Extraction of lithium, rubidium, and cesium from minerals

Abstract

Disclosed herein are methods of extracting lithium from a lithium containing material such as spodumene. Also disclosed are methods of extraction lithium, rubidium, and cesium from a material containing the same, for example lepidolite. The disclosed processes provide higher extraction efficiency and lower energy inputs relative to previously disclosed extractive processes.

Description

Attorney Docket No. 11196 114WO1EXTRACTION OF LITHIUM, RUBIDIUM, AND CESIUM FROM MINERALSCROSS REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of U.S. Provisional Applications 63 / 551,313, filed February8, 2024, and 63 / 682,618, filed August 13, 2024, the contents of each are hereby incorporated in itsentirety. BACKGROUND

[0002] The quest for sustainable energy solutions has significantly increased the demand for criticalmetals, particularly lithium (Li), rubidium (Rb), and cesium (Cs), owing to their indispensable roles invarious high tech industries such as aerospace, defense, and new energy applications. Lithium hasbecome an irreplaceable component of energy storage devices with the expansion of the renewableenergy (RE) sector and the reduction of fossil fuel based energy generation. The surging demand forhybrid and electric vehicles (EVs) requires rechargeable batteries, and Li will almost exclusively betheir fuel. Due to its physical, chemical, and electrochemical properties such as low density (0.534gcm 3), high specific capacity (~3.8 Ah g 1), and high electrochemical potential (~3 V), Li has beenapplied in many other sectors such as in the fabrication of nonlinear optics, high temperaturelubricants, alloys, heat transfer applications, chemical and pharmaceuticals industry, as well asnuclear research. By 2015, the majority of global Li production (~60%) was consumed for nonbattery. However, debates on global de carbonization, and implementation of the United NationsSustainable Development Goals (SDGs) urged renewable energy harvesting and storage, which hascaptured alarming attention on Li due to the substantial increase in Li consumption. Cesium, thehighest electropositive and the least abundant of the five naturally occurring alkali metals, and Rb,exhibit exceptional photoelectric properties essential for precision instruments like atomic clocksand satellite navigation systems

[0003] According to the present understanding, Li resources are not scarce, and it will not be alimiting constraint in this century. About two thirds of the global demand for Li is produced frombrine sources, while the rest is compensated by processing Li ores, such as those composed ofspodumene (LiAlSi2O6) – the major Li mineral. However, the recent increased demand for batteriesand various projections shows that the Li production must be escalated to tackle any future supplyrisks. Therefore, research and development are required to address technical, economic, andenvironmental bottlenecks for extraction of Li from all viable sources. In contrast, Rb and Cs have noprimary source and are mainly obtained as by products during Li extraction from lepidolite. Thescarcity of these two critical metals has led to their exceedingly high market prices. Moreover, manyAttorney Docket No. 11196 114WO1countries including the United States rely entirely on imports of these metals, primarily from Canadaand China.

[0004] Spodumene is an inosilicate belonging to the pyroxene group that can accommodate threedifferent crystal structures , and , where spodumene is the naturally occurring phase. In thisintact monoclinic structure, Li occupies cavities between Si centered tetrahedra and Al centeredoctahedra making it difficult to be readily leached. The conventional methods for extracting Li fromspodumene involve a series of complex and energy intensive steps. These methods mainly requirethe conversion of spodumene to spodumene (a porous and leachable phase) through hightemperature (~1100 °C) calcination for about two hours. The spodumene is then subjected tosulfuric acid baking at 250 °C, where Li undergoes ion exchange with H to form Li2SO4. The lithiumsulfate product is then extracted through water leaching at 90 °C. Following dissolution of metalsulfates, CaCO3 is added to the product solution to neutralize excess H2SO4 and adjust pH to removeimpurities. Finally, Na2CO3 is added to precipitate Li2CO3, which is a precursor to the production ofLiOH. However, these methods suffer mainly from high energy consumption and greenhouse gasemission (GHG) during the calcination process.

[0005] Additionally, the industrial kilns have low efficiency for phase transformation of spodumenefrom to (due to temperature gradient and variation in particle size of spodumene concentrate),thereby reducing Li recovery in the downstream process. The potential for the generation of highlytoxic by products, such as arsenic trioxide (formation usually begins above 500 °C due to oxidation)during the high temperature calcination, has also been a recent concern in the industry.Furthermore, high corrosive acid consumption and required maintenance, as well as high baseconsumption in downstream purification processes are disadvantages of the acid baking process inthis method.

[0006] In this regard, studies have focused on the direct extraction of Li from spodumene usingvarious techniques such dry chlorination, hydrofluoric decomposition, and microbial digestion toeliminate the high temperature calcination process. Dry chlorination suffers from the required hightemperature (1000 °C) and the loss of Li in the form of gaseous lithium chloride (LiCl). The toxicity ofhydrofluoric acid and slow kinetics of reactions by microorganisms to digest spodumene haverestricted their industrial application. Therefore, there is a pressing need to develop an alternativeextraction process that is more efficient, environmentally friendly, and cost effective.

[0007] There remains a need for improved methods for obtaining critical metals, including lithium,cesium, and rubidium, from mineral sources. There remains a need for improved methods forrecovering lithium from lithium bearing materials, including spodumene sources. There remains aneed for improved methods for extracting lithium, cesium, and rubidium, with lower energy inputs,Attorney Docket No. 11196 114WO1less toxic and / or costly reagents, and / or lower environmental harms. There remains a need forimproved methods for recovering lithium from lithium bearing materials with lower energy inputs,less toxic and / or costly reagents, and / or lower environmental harms.BRIEF DESCRIPTION OF THE FIGURES

[0008] Figure 1 depicts X ray diffraction pattern of raw spodumene concentrate.

[0009] Figure 2 depicts grain size distribution and SEM image of raw spodumene concentrate.

[0010] Figure 3 depicts the effect of the weight ratio of NaOH to spodumene on Li extraction(roasting at 325 °C for 2 h; leaching at room temperature with S / L = 1% and 400 rpm for 2 h). Errorbars represent 95% C.I. as calculated from at least three repeat experiments).

[0011] Figure 4 depicts calculated equilibrium products for different NaOH to spodumene ratiosof the roasting process by FactSage 8.3.

[0012] Figure 5 depicts X ray diffractograms of spodumene roasted with different mass ratios ofNaOH. The corresponding mineral phases with symbols in diffractograms are as follows: A: LiAl(SiO4),B: Li2Al2Si4O12(H2O)2, C: Li2SiO3, D: Li3NaSiO4, E: Li0.33Al0.33Si0.67O2, F: NaAlO2, G: Na0.775Al0.775Si0.775O2, H:NaAlSiO4, I: NaAlSi2O6, J: Na(AlSi3O8), K: Na3Li2Al(SiO4)2, L: NaCaAl(Si2O7), M: Na2SiO3, N:NaAlSi2O6 H2O, O: Na4(SiO4), P: K2LiAlH6, Q: SiO2, R: KAlSi3O8, S: spodumene (LiAlSi2O6), T:Ca3(SiO4)O, U: CaSiO3, V: Ca2SiO4, W: Al(OH)3.

[0013] Figure 6 depicts the effect of roasting temperature on lithium extraction from spodumene(roasting at 1.5:1 NaOH to spodumene ratio for 2 h; water leaching at room temperature withsolid to liquid ratio of 1% and 400 rpm for 2 h).

[0014] Figure 7 depicts variation of enthalpy ( H) and Gibb’s free energy ( G) of NaOHspodumene reaction with roasting temperature.

[0015] Figure 8 depicts phase transformations of spodumene roasted at 1.5:1 NaOH tospodumene (weight ratio) investigated at different temperatures. The corresponding mineral phaseswith symbols in diffractograms are as follows: A: LiAl(SiO4), B: Li2Al2Si4O12(H2O)2, C: Li2SiO3, D:Li3NaSiO4, E: Li0.33Al0.33Si0.67O2, F: NaAlO2, G: Na0.775Al0.775Si0.775O2, H: NaAlSiO4, I: NaAlSi2O6, J:Na(AlSi3O8), K: Na3Li2Al(SiO4)2, Q: SiO2, S: spodumene (LiAlSi2O6).

[0016] Figure 9 depicts the effect of roasting time on Li extraction for 1.5:1 NaOH: spodumene atroasting temperature of 325 °C (leaching at room temperature with S / L = 1% and 400 rpm for 2 h).

[0017] Figure 10 depicts a Thermogravimetric Derivative Thermogravimetric (TG DTG) curve ofNaOH spodumene reaction at optimum conditions.

[0018] Figure 11 depicts the effect of solid to liquid ratio on Li extraction (leaching at roomtemperature at 100 rpm for 30 min.).Attorney Docket No. 11196 114WO1

[0019] Figure 12 depicts the effect of leaching reaction temperature on Li recovery (leaching withsolid to liquid ratio = 10% for 30 min.).

[0020] Figure 13 depicts variation of enthalpy ( H) and Gibb’s free energy ( G) with leachingtemperature.

[0021] Figure 14 depicts X ray diffractogram and SEM image of spodumene (a) concentrate, (b)roasted with NaOH, and (c) NaOH roasted and water leached. (Note: The diffraction intensity of thisfigure was intentionally increased to highlight complexity of roasting with the formation of differentproducts). The corresponding mineral phases with the symbols in diffractograms are as following: A:Na0.775Al0.775Si0.775O2, H: NaAlSiO4, I: NaAlSi2O6, J: Na(AlSi3O8), K: Na3Li2Al(SiO4)2, L: NaCaAl(Si2O7), M:Na2SiO3, N: NaAlSi2O6 H2O, O: Na4(SiO4), P: K2LiAlH6, Q: SiO2, R: KAlSi3O8, S: spodumene (LiAlSi2O6),T: Ca3(SiO4)O, U: CaSiO3, V: Ca2SiO4, W: Al(OH)3.

[0022] Figure 15 depicts an illustration of shrinking core model during NaOH roasting ofspodumene and the corresponding SEM image observed from the surface.

[0023] Figure 16 depicts (a) effect of varying the weight ratio of NaOH on the extraction of Li fromstage 1 residue (roasting for 2 h; leaching at room temperature with S / L = 2% and 100 rpm for 2 h),(b) Thermogravimetric Derivative Thermogravimetric (TG DTG) curve of NaOH stage 1 residuereaction, (c) effect of roasting temperature on Li extraction from stage 1 residue, (d) effect ofroasting duration on Li extraction from stage 1 residue at a roasting temperature of 325 °C.

[0024] Figure 17 depicts the effect of (a) solid to liquid ratio on Li extraction, (b) stirring speed on Liextraction using 1% solid to liquid ratio at room temperature, and (c) leaching temperature on Lirecovery at 1% solid to liquid ratio and 200 rpm.

[0025] Figure 18 depicts a schematic of an extraction protocol.

[0026] Figure 19 depicts a summary of the direct Li extraction process.

[0027] Figure 20 depicts X ray diffraction pattern and scanning electron microscopic image of (a)lepidolite concentrate, (b) sample roasted with NaOH showing product formation, NaOH diffusionand the complexity of the roasting process, and (c) process residue after water leaching showing thepresence of undissolved Li containing species. (Note: The diffraction intensities of this figure wereintentionally increased to highlight complexity of roasting with the formation of different products).The corresponding mineral phases with the symbols in diffractograms are as follows: A albite(NaAlSi3O8), B lithium aluminum oxide (Li5AlO4), C lithium oxide (Li2O), D lithium sodium silicate(Li3NaSiO4), E lithium metasilicate (Li2SiO3), F ephesite (NaLiAl4(SiO4)2O2(OH)2), G sodiumorthosilicate (Na4SiO4), H sodium metasilicate (Na2SiO3), I sodium aluminate (NaAlO2), JAttorney Docket No. 11196 114WO1natrosilite (Na2Si2O5), K sodium aluminum silicate (Na5AlO4), L lepidolite(K(Li,Al)3(Al,Si)4O10(F,OH)2)), and Q quartz (SiO2).

[0028] Figure 21 depicts Thermogravimetric Derivative Thermogravimetric (TG DTG) curve ofNaOH lepidolite reaction.

[0029] Figure 22 depicts elemental recovery during the water leaching of NaOH roasted lepidolite(stirring rate 400 rpm, solid liquid ratio 10%, temperature 25 °C, time 2 h), compared with thethree baseline methods.DETAILED DESCRIPTION

[0030] Before the present methods and systems are disclosed and described, it is to be understoodthat the methods and systems are not limited to specific synthetic methods, specific components, orto particular compositions. It is also to be understood that the terminology used herein is for thepurpose of describing particular embodiments only and is not intended to be limiting.

[0031] As used in the specification and the appended claims, the singular forms “a,” “an” and “the”include plural referents unless the context clearly dictates otherwise. Ranges may be expressedherein as from “about” one particular value, and / or to “about” another particular value. When sucha range is expressed, another embodiment includesfrom the one particular value and / or to theother particular value. Similarly, when values are expressed as approximations, by use of theantecedent “about,” it will be understood that the particular value forms another embodiment. Itwill be further understood that the endpoints of each of the ranges are significant both in relation tothe other endpoint, and independently of the other endpoint.

[0032] “Optional” or “optionally” means that the subsequently described event or circumstancemay or may not occur, and that the description includes instances where said event or circumstanceoccurs and instances where it does not.

[0033] Throughout the description and claims of this specification, the word “comprise” andvariations of the word, such as “comprising” and “comprises,” means “including but not limited to,”and is not intended to exclude, for example, other additives, components, integers or steps.“Exemplary” means “an example of” and is not intended to convey an indication of a preferred orideal embodiment. “Such as” is not used in a restrictive sense, but for explanatory purposes.

[0034] The term "lithium bearing material" is used interchangeably with “lithium containingmaterial” and as used herein refers to any lithium containing substance. The term may be usedpredominantly to refer to naturally occurring minerals that contain lithium values, including but notlimited to silicates, fluorophosphate, borosilicates, aluminum silicates, phosphates such asamblygonite, lithium containing micas, and lithium containing clays. In some aspects, as disclosedAttorney Docket No. 11196 114WO1herein, the lithium bearing materials can be used as naturally occurring ores. Yet, in other aspects,the lithium bearing materials can be used as concentrates.

[0035] It will be appreciated by those skilled in the art that the lithium bearing material maycomprise one or more naturally occurring lithium minerals because they frequently occur together,for example, in pegmatite bodies. Several metals, such as Mn, Rb and Cs, and other minerals such asquartz, albite, feldspar, topaz and beryl may also be associated with these lithium minerals.Accordingly, the term "lithium bearing material" encompasses high grade ores and concentrates aswell as medium to low grade ores, concentrates and blends thereof.

[0036] Exemplary lithium bearing materials include, but are not limited to, jadarite, spodumeneand other pyroxenes, trilithionite, petalite and other lithium bearing silicates from the nephelinegroup of minerals, holmquistite and other lithium bearing silicates from the amphibole group ofminerals, lepidolite, zinwaldite, elbaite and other tourmalines, chlorites, smectites, lithiumcontaining micas, and lithium containing clays.

[0037] Disclosed are components that can be used to perform the disclosed methods and systems.These and other components are disclosed herein, and it is understood that when combinations,subsets, interactions, groups, etc. of these components are disclosed that while specific reference ofeach various individual and collective combinations and permutation of these may not be explicitlydisclosed, each is specifically contemplated and described herein, for all methods and systems. Thisapplies to all aspects of this application including, but not limited to, steps in disclosed methods.Thus, if there are a variety of additional steps that can be performed it is understood that each ofthese additional steps can be performed with any specific embodiment or combination ofembodiments of the disclosed methods.

[0038] Disclosed herein are methods including the steps:a) contacting a lithium containing material with a first roasting agent at a first elevatedtemperature for a first period of time to provide a first water insoluble phase and a firstwater soluble phase;b) contacting the first water insoluble phase and first water soluble phase with a firstquantity of water to dissolve the first water soluble phase;c) separating the first water insoluble phase from the water comprising the first watersoluble phase;d) contacting the separated first water insoluble phase with a second roasting agent ata second elevated temperature for a second period of time to provide a second waterinsoluble phase and a second water soluble phase;Attorney Docket No. 11196 114WO1e) contacting the second water insoluble phase and second water soluble phase with asecond quantity of water to dissolve the second water soluble phase;f) separating the second water insoluble phase from the water comprising the secondwater soluble phase; andg) recovering lithium from the first water soluble phase and second water solublephase; wherein neither the first water insoluble phase nor second water insoluble phase arecontacted with an acid.

[0039] In some implementations, the lithium containing material is spodumene, lepidolite,hectorite, jadarite, Li enriched clays, Li batteries, waste streams of mining and processing of coaland coal by products and minerals and oil shale, coal underclay, coal overburden, recycled materials,or a combination thereof. In some implementations, the lithium containing material comprisesspodumene.

[0040] In some implementations, the method provides an extraction efficiency of at least 90%, atleast 95%, at least 97.5%, or at least 99%. As used herein, extraction efficiency is the percent lithiumextracted vs. the total lithium content of the lithium containing material.

[0041] In some implementations the lithium containing material has a particle size d50 (ASTM C13601) from 1 1,000 µm, from 10 1,000 µm, from 10 500 µm, from 50 500 µm, from 50 250 µm, from100 250 µm, or from 100 200 µm. The lithium containing material can have relatively small particlesize distribution. In some implementations the lithium containing material has a particle size d90(ASTM C136 01) that is no more than 5x the particle size d50 (ASTM C136 01), no more than 4x theparticle size d50 (ASTM C136 01), no more than 3x the particle size d50 (ASTM C136 01), or no morethan 2x the particle size d50 (ASTM C136 01).

[0042] In some implementations the lithium containing material further includes aluminum,calcium, iron, silicon, sodium, a rare earth element, or a combination thereof. In someimplementations, the disclosed methods provide an extraction selectivity of at least 50%, at least60%, at least 70%, at least 80%, or at least 90%. As used herein, extraction selectivity refers to theconcentration (wt.%) of lithium in the combined water soluble phases relative to the other metalspecies present. In some implementations, the combined water soluble phases contain Al in anamount less than 20 wt.%, less than 15 wt.%, less than 10 wt.%, less than 5 wt.%, or less than 1wt.%, relative to the lithium content of the combined phases.

[0043] In some implementations the lithium containing material further includes cesium andrubidium.Attorney Docket No. 11196 114WO1

[0044] In some implementations, the lithium containing material is lepidolite and the methodfurther provides recovering cesium and rubidium.

[0045] In some implementations the first roasting agent and lithium containing mineral are presentin a weight ratio from 10:1 to 1:10, from 1:1 to 1:10, from 1:1 to 1:5, from 2:1 to 1:2, from 10:1 to1:1, from 5:1 to 1:1, from 3:1 to 1:1, from 2:1 to 1:1, from 1.75 to 1.25, or 1.5:1.

[0046] In some implementations the first roasting agent and lithium containing mineral are presentin a weight ratio from 1.75 to 1.25.

[0047] In some implementations the lithium containing material includes spodumene, and the firstroasting agent and spodumene are present in a weight ratio from 10:1 to 1:10, from 1:1 to 1:10,from 1:1 to 1:5, from 2:1 to 1:2, from 10:1 to 1:1, from 5:1 to 1:1, from 3:1 to 1:1, from 2:1 to 1:1,from 1:1.75 to 1:1.25, or 1.5:1. In some implementations the spodumene is spodumene.

[0048] In some implementations the lithium containing material includes spodumene, and thefirst roasting agent and spodumene are present in a weight ratio from 1.75 to 1.25.

[0049] In some implementations the first roasting agent includes an alkali metal salt, an alkalineearth metal salt, an ammonium salt, or a combination thereof.

[0050] In some implementations the first roasting agent includes an alkali hydroxide, alkalicarbonate, alkali sulfate, alkali chloride, alkali nitrate, alkaline earth hydroxide, alkaline earthcarbonate, alkaline earth sulfate, alkaline earth chloride, alkaline earth nitrate, ammoniumhydroxide, ammonium carbonate, ammonium sulfate, ammonium chloride, ammonium nitrate, or acombination thereof.

[0051] In some implementations the first roasting agent includes NaOH, Na2CO3, KOH, K2CO3,MgCO3, CaCO3, BaCO3, NaCl, KCl, CaCl2, MgCl2, NaNO3, KNO3, Ca(NO3)2, Ba(NO3)2, Mg(NO3)2, Ca(OH)2,CaSO4, (NH4)2SO4, Na2SO4, or a combination thereof.

[0052] In some implementations the first roasting agent is NaOH.

[0053] In some implementations the first elevated temperature is greater than the melting point ofthe first roasting agent.

[0054] In some implementations the first elevated temperature is from 100 800 °C., from 200 800°C., from 200 700 °C., from 200 600 °C., from 200 500 °C., from 200 400 °C., from 250 400 °C., from250 350 °C., from 200 300 °C., from 300 350 °C., from 300 400 °C., or from 350 400 °C.

[0055] In some implementations the first elevated temperature is provided by microwaveirradiation of the lithium containing material and first roasting agent. In some implementations thefirst elevated temperature is provided by a heat transfer process, i.e., using a heating mantle orother heating source.Attorney Docket No. 11196 114WO1

[0056] In some implementations the first elevated temperature is provided by microwaveirradiation of the lithium containing material and first roasting agent, wherein the microwave sourcehas a frequency between about 900 MHz to about 6 GHz.

[0057] In some implementations the first elevated temperature is provided by microwaveirradiation of the lithium containing material and first roasting agent, wherein the microwave sourcehas an energy from 0.5 30 kW.

[0058] In some implementations the first period of time is from 1 second 12 hours, 1 minute 12hours, 0.1 12 hours, from 0.5 12 hours, from 1 12 hours, from 0.5 6 hours, from 0.5 3 hours, from 12.5 hours, from 1 3 hours, from 2 4 hours, from 1.5 2.5 hours, from 1 5 hours, from 2 10 hours, from5 10 hours or from 6 12 hours.

[0059] In some implementations the first period of time is from 1.5 2.5 hours.

[0060] In some implementations step (a) is performed at a pressure from 0.1 20 MPa.

[0061] In some implementations the first water insoluble phase and first water soluble phase aresubjected to size reduction prior to contacting with the first quantity of water.

[0062] In some implementations the first quantity of water is provided at a solids:liquid ratio from0.1 10 wt.%, from 0.1 5 wt.%, from 0.1 2.5 wt.%, from 0.5 2.5 wt.%, or from 0.5 1.5 wt.%, from 1 20wt.%, from 1 15 wt.%, from 2 10 wt.%, from 2 5 wt.%, from 5 10 wt.%, or from 5 15 wt.%.

[0063] In some implementations the first quantity of water is provided at a solids:liquid ratio from5 15 wt.%.

[0064] In some implementations the lithium containing material is spodumene, and the firstquantity of water is provided at a solids:liquid ratio from 0.1 20 wt.%, from 0.1 10 wt.%, from 0.1 5wt.%, from 0.1 2.5 wt.%, from 0.5 2.5 wt.%, from 0.5 1.5 wt.%, from 1 20 wt.%, from 1 15 wt.%,from 2 10 wt.%, from 2 5 wt.%, from 5 10 wt.%, from 7.5 12.5 wt.%, or from 5 15 wt.%. In someimplementations the spodumene is spodumene.

[0065] In some implementations the lithium containing material is spodumene, and the firstquantity of water is provided at a solids:liquid ratio from 7.5 12.5 wt.%.

[0066] In some implementations the first water insoluble phase and first water soluble phase arecontacted with the first quantity of water for a period from 1 second 1 minute, 1 second 5 minutes,1 second 60 minutes, 0.1 60 minutes, from 0.1 30 minutes, from 0.1 20 minutes, from 0.1 10minutes, from 0.1 5 minutes, from 0.5 2.5 minutes, or from 0.5 1.5 minutes.

[0067] In some implementations the first water insoluble phase and first water soluble phase arecontacted with the first quantity of water for a period from 0.5 1.5 minutes.

[0068] In some implementations the first water insoluble phase and first water soluble phase arecontacted with the first quantity of water at a temperature from 0 50 °C., from 5 50 °C., from 10 50Attorney Docket No. 11196 114WO1°C., 15 50 °C., from 15 40 °C., from 15 30 °C., from 25 50 °C., from 25 40 °C., from 25 30 °C., from20 30 °C., from 30 40 °C., or from 35 50 °C.

[0069] In some implementations the first water insoluble phase and first water soluble phase arecontacted with the first quantity of water at a temperature from 20 30 °C.

[0070] In some implementations the first water insoluble phase and first water soluble phase arecontacted with the first quantity of water with agitation.

[0071] In some implementations the first water insoluble phase and first water soluble phase arecontacted with the first quantity of water using countercurrent leaching.

[0072] In some implementations the first water insoluble phase and first water soluble phase arecontacted with the first quantity of water with stirring.

[0073] In some implementations the first water insoluble phase and first water soluble phase arecontacted with the first quantity of water with stirring at a rate from 1 1,200 rpm, from 100 1,200rpm, from 100 800 rpm, from 100 600 rpm, from 200 600 rpm, from 300 500 rpm, from 300 1,200rpm, from 600 1,200 rpm, from 10 250 rpm, from 50 250 rpm, from 50 150 rpm, or from 75 125rpm.

[0074] In some implementations the first water insoluble phase and first water soluble phase arecontacted with the first quantity of water with stirring at a rate from 75 125 rpm.

[0075] In some implementations contacting the first water insoluble phase and first water solublephase with the first quantity of water produces a solution having a pH from 10 15, from 11 15, from11 14, from 12 14, or from 12.5 13.5.

[0076] In some implementations the first water insoluble phase is separated from the watercomprising the first water soluble phase by filtration.

[0077] In some implementations the first water insoluble phase is separated from the watercomprising the first water soluble phase by filtration using a filter having a membrane pore size from0.05 50 µm, from 0.05 25 µm, from 0.05 10 µm, from 0.05 2 µm, from 0.1 2 µm, from 0.1 1.5 µm,from 0.1 1 µm, from 0.1 0.5 µm, from 0.25 1 µm, from 0.25 0.5 µm, from 1 10 µm, from 1 5 µm,from 5 25 µm, from 5 50 µm, or from 25 50 µm.

[0078] In some implementations the separated first water insoluble phase is dried prior to beingcontacted with the second roasting agent. In some implementations the first water insoluble phaseis dried to constant weight prior to being contacted with the second roasting agent.

[0079] In some implementations the second roasting agent includes an alkali metal salt, an alkalineearth metal salt, an ammonium salt, or a combination thereof.

[0080] In some implementations the second roasting agent includes an alkali hydroxide, alkalicarbonate, alkali sulfate, alkali chloride, alkali nitrate, alkaline earth hydroxide, alkaline earthAttorney Docket No. 11196 114WO1carbonate, alkaline earth sulfate, alkaline earth chloride, alkaline earth nitrate, ammoniumhydroxide, ammonium carbonate, ammonium sulfate, ammonium chloride, ammonium nitrate, or acombination thereof.

[0081] In some implementations the second roasting agent includes NaOH, Na2CO3, KOH, K2CO3,MgCO3, CaCO3, BaCO3, NaCl, KCl, CaCl2, MgCl2, NaNO3, KNO3, Ca(NO3)2, Ba(NO3)2, Mg(NO3)2, Ca(OH)2,CaSO4, (NH4)2SO4, Na2SO4, or a combination thereof.

[0082] In some implementations the second roasting agent includes NaOH.

[0083] In some implementations the second elevated temperature is greater than the melting pointof the second roasting agent.

[0084] In some implementations the first roasting agent is employed in greater amount than thesecond roasting agent.

[0085] In some implementations the first roasting agent is employed in an amount that is from 100250%, 100 200%, 100 150%, 100 125%, 125 150%, 125 175%, 150 175%, 150 200%, or 175 200%the amount of the second roasting agent.

[0086] In some implementations the second roasting agent and first water insoluble phase arepresent in a weight ratio from 10:1 to 1:10, from 1:1 to 1:10, from 1:1 to 1:5, from 2:1 to 1:2, from10:1 to 1:1, from 5:1 to 1:1, from 3:1 to 1:1, from 2:1 to 1:1, from 1:1.75 to 1:1.25, from 0.1:1 to 1:2,from 0.5:1 to 1:2, from 0.5:1 to 1:1.5, or from 0.75:1 to 1:1.25.

[0087] In some implementations the first roasting agent and first water insoluble phase are presentin a weight ratio from 1:0.75 to 1:1.25.

[0088] In some implementations the second elevated temperature is from 100 800 °C., from 200800 °C., from 200 700 °C., from 200 600 °C., from 200 500 °C., from 200 400 °C., from 250 400 °C.,from 250 350 °C., from 200 300 °C., from 300 350 °C., from 300 400 °C., or from 350 400 °C.

[0089] In some implementations the second elevated temperature is provided by microwaveirradiation of the first water insoluble phase and second roasting agent. In some implementationsthe second elevated temperature is provided by a heat transfer process, i.e., using a heating mantleor other heating source.

[0090] In some implementations the second elevated temperature is provided by microwaveirradiation of the first water insoluble phase and second roasting agent, wherein the microwavesource has a frequency between about 900 MHz to about 6 GHz.

[0091] In some implementations the second elevated temperature is provided by microwaveirradiation of the first water insoluble phase and second roasting agent, wherein the microwavesource has an energy from 0.5 30 kW.

[0092] In some implementations the second period of time is less than the first period of time.Attorney Docket No. 11196 114WO1

[0093] In some implementations the second period of time is from 1 50%, from 1 25%, from 1 10%,from 1 5%, from 2 10%, from 2 6%, from 5 10%, from 10 25%, from 25 50%, or from 25 75% thefirst period of time.

[0094] In some implementations the second period of time is from 5 10% the first period of time.

[0095] In some implementations the second period of time is from 1 second 60 minutes, 0.1 60minutes, from 1 60 minutes, from 1 30 minutes, from 1 15 minutes, from 1 10 minutes, from 1 5minutes, from 5 15 minutes, from 10 25 minutes, from 10 60 minutes, or from 30 60 minutes.

[0096] In some implementations step (d) is performed at a pressure from 0.1 20 MPa.

[0097] In some implementations the second water insoluble phase and second water soluble phaseare subjected to size reduction prior to contacting with the second quantity of water.

[0098] In some implementations the second quantity of water is greater than the first quantity ofwater.

[0099] In some implementations the second quantity of water is in an amount from 100 2,000%,from 100 1,000%, from 100 500%, from 100 250%, from 250 750%, from 250 500%, from 5001,000%, from 500 1,500% from 1000 2,000% the first quantity of water.

[0100] In some implementations the second quantity of water is provided is provided at asolids:liquid ratio from 0.1 10 wt.%, from 0.1 5 wt.%, from 0.1 2.5 wt.%, from 0.5 2.5 wt.%, from 0.51.5 wt.%, from 1 20 wt.%, from 1 15 wt.%, from 2 10 wt.%, from 2 5 wt.%, from 5 10 wt.%, or from5 15 wt.%.

[0101] The method of claim 1, wherein the second quantity of water is provided at a solids:liquidratio from 0.5 2.5 wt.%.

[0102] In some implementations the second water insoluble phase and second water soluble phaseare contacted with the second quantity of water for a period from 1 second 1 minute, 1 second 5minutes, 1 second 30 minutes, 0.1 30 minutes, from 0.1 20 minutes, from 1 20 minutes, 2 20minutes, from 5 20 minutes, from 5 15 minutes, or from 10 20 minutes.

[0103] In some implementations the second water insoluble phase and second water soluble phaseare contacted with the second quantity of water for a period from 5 15 minutes.

[0104] In some implementations wherein the second water insoluble phase and second watersoluble phase are contacted with the second quantity of water at a temperature from 0 50 °C., from5 50 °C., from 10 50 °C., 15 50 °C., from 15 40 °C., from 15 30 °C., from 25 50 °C., from 25 40 °C.,from 25 30 °C., from 20 30 °C., from 30 40 °C., or from 35 50 °C.

[0105] In some implementations the second water insoluble phase and second water soluble phaseare contacted with the second quantity of water with agitation.Attorney Docket No. 11196 114WO1

[0106] In some implementations the second water insoluble phase and second water soluble phaseare contacted with the second quantity of water using countercurrent leaching.

[0107] In some implementations the second water insoluble phase and second water soluble phaseare contacted with the second quantity of water with stirring.

[0108] In some implementations the second water insoluble phase and second water soluble phaseare contacted with the second quantity of water with stirring at a rate from 100 1,200 rpm, from100 800 rpm, from 100 600 rpm, from 100 500 rpm, from 100 250 rpm, from 150 250 rpm, from200 600 rpm, from 300 500 rpm, from 300 1,200 rpm, or from 600 1,200 rpm.

[0109] In some implementations the second water insoluble phase and second water soluble phaseare contacted with the second quantity of water with stirring at a rate from 150 250 rpm.

[0110] In some implementations contacting the second water insoluble phase and second watersoluble phase with the second quantity of water produces a solution having a pH from 10 15, from11 15, from 11 14, from 12 14, or from 12.5 13.5.

[0111] In some implementations the second water insoluble phase is separated from the watercontaining the second water soluble phase by filtration.

[0112] In some implementations the second water insoluble phase is separated from the watercontaining the second water soluble phase by filtration using a filter having a membrane pore sizefrom 0.05 2 µm, from 0.1 2 µm, from 0.1 1.5 µm, from 0.1 1 µm, from 0.1 0.5 µm, from 0.25 1 µm,or from 0.25 0.5 µm.

[0113] In some implementations the first water soluble phase and second water soluble phase arecombined, and lithium is recovered from the combined phases.

[0114] Also disclosed herein are methods including the steps:a) contacting a material including cesium, rubidium, and lithium with a roasting agent at anelevated temperature for a period of time to provide a water insoluble phase and a watersoluble phase;b) contacting the water insoluble phase and water soluble phase with a quantity of water todissolve the water soluble phase;c) separating the water insoluble phase from the water comprising the water soluble phase;and d) recovering cesium, rubidium, and lithium from the water soluble phase.

[0115] In some implementations the first water insoluble phase obtained from the materialincluding cesium, rubidium, and lithium is not contacted with an acid, for example HF.Attorney Docket No. 11196 114WO1

[0116] In some implementations, the material including cesium, rubidium, and lithium includeslepidolite, pollucite, leucite, carnallite, and amblygonite, biotite, recycled materials, or acombination thereof.

[0117] In some implementations the material including cesium, rubidium, and lithium is lepidolite.

[0118] In some implementations the material including cesium, rubidium, and lithium has a particlesize d50 (ASTM C136 01) from 1 1,000 µm, from 10 1,000 µm, from 10 500 µm, from 50 500 µm,from 50 250 µm, from 100 250 µm, or from 100 200 µm.

[0119] In some implementations the material including cesium, rubidium, and lithium has a particlesize d90 (ASTM C136 01) that is no more than 5x the particle size d90 (ASTM C136 01), no more than4x the particle size d50 (ASTM C136 01), no more than 3x the particle size d50 (ASTM C136 01), or nomore than 2x the particle size d50 (ASTM C136 01).

[0120] In some implementations the roasting agent and material including cesium, rubidium, andlithium are present in a weight ratio from 10:1 to 1:10, from 1:1 to 1:10, from 1:1 to 1:5, from 2:1 to1:2, from 10:1 to 1:1, from 5:1 to 1:1, from 3:1 to 1:1, from 2:1 to 1:1, from 1.75 to 1.25, or 1.5:1.

[0121] In some implementations the roasting agent and the material including cesium, rubidium,and lithium are present in a weight ratio from 1.75 to 1.25.

[0122] In some implementations the material including cesium, rubidium, and lithium is lepidolite,and the roasting agent and lepidolite are present in a weight ratio from 10:1 to 1:10, from 1:1 to1:10, from 1:1 to 1:5, from 2:1 to 1:2, from 10:1 to 1:1, from 5:1 to 1:1, from 3:1 to 1:1, from 2:1 to1:1, from 1:1.75 to 1:1.25, or 1.5:1.

[0123] In some implementations the material including cesium, rubidium, and lithium is lepidolite,and the roasting agent and lepidolite are present in a weight ratio from 1.75 to 1.25.

[0124] In some implementations the roasting agent includes an alkali metal salt, an alkaline earthmetal salt, an ammonium salt, or a combination thereof.

[0125] In some implementations the roasting agent includes an alkali hydroxide, alkali carbonate,alkali sulfate, alkali chloride, alkali nitrate, alkaline earth hydroxide, alkaline earth carbonate,alkaline earth sulfate, alkaline earth chloride, alkaline earth nitrate, ammonium hydroxide,ammonium carbonate, ammonium sulfate, ammonium chloride, ammonium nitrate, or acombination thereof.

[0126] In some implementations the roasting agent includes NaOH, Na2CO3, KOH, K2CO3, MgCO3,CaCO3, BaCO3, NaCl, KCl, CaCl2, MgCl2, NaNO3, KNO3, Ca(NO3)2, Ba(NO3)2, Mg(NO3)2, Ca(OH)2, CaSO4,(NH4)2SO4, Na2SO4, or a combination thereof.

[0127] In some implementations the roasting agent includes NaOH.Attorney Docket No. 11196 114WO1

[0128] In some implementations the elevated temperature is greater than the melting point of theroasting agent.

[0129] In some implementations the elevated temperature is from 100 800 °C., from 200 800 °C.,from 200 700 °C., from 200 600 °C., from 200 500 °C., from 200 400 °C., from 250 400 °C., from 250350 °C., from 200 300 °C., from 300 350 °C., from 300 400 °C., or from 350 400 °C.

[0130] In some implementations the elevated temperature is provided by microwave irradiation ofthe material including cesium, rubidium, and lithium and first roasting agent. In someimplementations the elevated temperature is provided by a heat transfer process, i.e., using aheating mantle or other heating source.

[0131] In some implementations the elevated temperature is provided by microwave irradiation ofthe material including cesium, rubidium, and lithium and roasting agent, wherein the microwavesource has a frequency between about 900 MHz to about 6 GHz.

[0132] In some implementations the elevated temperature is provided by microwave irradiation ofthe material including cesium, rubidium, and lithium and roasting agent, wherein the microwavesource has an energy from 0.5 30 kW.

[0133] In some implementations the period of time is from 1 second 12 hours, 1 minute 12 hours,0.1 12 hours, from 0.5 12 hours, from 1 12 hours, from 0.5 6 hours, from 0.5 3 hours, from 1 2.5hours, from 1 3 hours, from 2 4 hours, from 1.5 2.5 hours, from 1 5 hours, from 2 10 hours, from 510 hours or from 6 12 hours.

[0134] In some implementations the period of time is from 1.5 2.5 hours.

[0135] In some implementations step (a) is performed at a pressure from 0.1 20 MPa.

[0136] In some implementations the water insoluble phase and water soluble phase are subjectedto size reduction prior to contacting with the first quantity of water.

[0137] In some implementations the quantity of water is provided at a solids:liquid ratio from 0.110 wt.%, from 0.1 5 wt.%, from 0.1 2.5 wt.%, from 0.5 2.5 wt.%, or from 0.5 1.5 wt.%, from 1 20wt.%, from 1 15 wt.%, from 2 10 wt.%, from 2 5 wt.%, from 5 10 wt.%, or from 5 15 wt.%.

[0138] In some implementations the quantity of water is provided at a solids:liquid ratio from 5 15wt.%.

[0139] In some implementations the material including cesium, rubidium, and lithium is lepidolite,and the quantity of water is provided at a solids:liquid ratio from 0.1 20 wt.%, from 0.1 10 wt.%,from 0.1 5 wt.%, from 0.1 2.5 wt.%, from 0.5 2.5 wt.%, from 0.5 1.5 wt.%, from 1 20 wt.%, from 115 wt.%, from 2 10 wt.%, from 2 5 wt.%, from 5 10 wt.%, from 7.5 12.5 wt.%, or from 5 15 wt.%.

[0140] In some implementations the material including cesium, rubidium, and lithium is lepidolite,and the quantity of water is provided at a solids:liquid ratio from 7.5 12.5 wt.%.Attorney Docket No. 11196 114WO1

[0141] In some implementations the water insoluble phase and water soluble phase are contactedwith the quantity of water for a period from 1 second 6 hours, 1 minute 6 hours, 0.1 6 hours, from1 6 hours, from 1 4 hours, from 1 2 hours, from 1.5 2.5 hours, from 0.1 1 hours, from 0.1 0.5 hours,or from 3 6 hours.

[0142] In some implementations the water insoluble phase and water soluble phase are contactedwith the quantity of water for a period from 1.5 2.5 hours.

[0143] In some implementations the water insoluble phase and water soluble phase are contactedwith the quantity of water at a temperature from 0 50 °C., from 5 50 °C., from 10 50 °C., 15 50 °C.,from 15 40 °C., from 15 30 °C., from 25 50 °C., from 25 40 °C., from 25 30 °C., from 20 30 °C., from30 40 °C., or from 35 50 °C.

[0144] In some implementations the water insoluble phase and water soluble phase are contactedwith the quantity of water at a temperature from 20 30 °C.

[0145] In some implementations the water insoluble phase and water soluble phase are contactedwith the quantity of water with agitation.

[0146] In some implementations the water insoluble phase and water soluble phase are contactedwith the quantity of water using countercurrent leaching.

[0147] In some implementations the water insoluble phase and water soluble phase are contactedwith the quantity of water with stirring.

[0148] In some implementations the water insoluble phase and water soluble phase are contactedwith the quantity of water with stirring at a rate from 1 1,200 rpm, from 100 1,200 rpm, from 100800 rpm, from 100 600 rpm, from 200 600 rpm, from 300 500 rpm, from 300 1,200 rpm, from 6001,200 rpm, from 10 250 rpm, from 50 250 rpm, from 50 150 rpm, or from 75 125 rpm.

[0149] In some implementations the water insoluble phase and water soluble phase are contactedwith the quantity of water with stirring at a rate from 300 500 rpm.

[0150] In some implementations contacting the water insoluble phase and water soluble phasewith the quantity of water produces a solution having a pH from 10 15, from 11 15, from 11 14,from 12 14, or from 12.5 13.5.

[0151] In some implementations the water insoluble phase is separated from the water comprisingthe water soluble phase by filtration.

[0152] In some implementations the water insoluble phase is separated from the water comprisingthe water soluble phase by filtration using a filter having a membrane pore size from 0.05 50 µm,from 0.05 25 µm, from 0.05 10 µm, from 0.05 2 µm, from 0.1 2 µm, from 0.1 1.5 µm, from 0.1 1µm, from 0.1 0.5 µm, from 0.25 1 µm, from 0.25 0.5 µm, from 1 10 µm, from 1 5 µm, from 5 25 µm,from 5 50 µm, or from 25 50 µm.Attorney Docket No. 11196 114WO1EXAMPLES

[0153] The following examples are for the purpose of illustration of the invention only and are notintended to limit the scope of the present invention in any manner whatsoever.

[0154] A raw spodumene sample from the Carolina Tin Spodumene Belt (North Carolina, USA) wasprovided by Piedmont Lithium Inc. According to the mineralogical analysis, the abundance ofspodumene, quartz, feldspar, and mica in the sample were recorded as ~20% (~1.6% Li2O), ~30%,~40% and ~5%, respectively. The sample also contained traces of biotite, other silicates, calcite,pyrite, chlorite, and apatite. The sample was subjected to pilot scale physical separationencompassing size reduction, flotation and magnetic separation at Minerals Research Laboratory,North Carolina State University, to obtain a spodumene concentrate. The spodumene concentratewas analyzed for mineralogical content by X ray diffraction (XRD) (i.e., quantitative analysis –Rietveld refinement method), which showed that the concentrate contains 93 ± 1.5% spodumeneand 7 ± 1.5% quartz confirming the dominance of Li, Si and Al in the composition of spodumene.Figure 1.

[0155] Size analysis of the concentrate conducted according to the ASTM C136 01 showed thesample has a d50and d90 of 144 m and 236 m, respectively. This was also confirmed by the sizeanalysis under scanning electron microscope (SEM) (Figure 2). The composition of spodumeneconcentrate was analyzed by a Thermo Scientific iCAP 7400 ICP AES at the Laboratory for Isotopesand Metals in the Environment (LIME) and an Agilent 7800 ICP MS at the Centre for Critical Minerals(C2M), of The Pennsylvania State University (Penn State). For ICP analyses, at least threerepresentative samples ( spodumene concentrate) were digested according to the ASTM D6357 11standard and Lithium Metaborate fusion methods. The elemental content showed that thisconcentrate is compatible with a typical spodumene feedstock used in conventional calcination andLi extraction processes (i.e., containing ~6% Li2O and <1% Fe2O3). It also showed trace amounts ofNa, K, and Ca in the sample. These elements, which could be present as isomorphic substitutionswithin the spodumene crystal lattice were below the detection limit of XRD.

[0156] Analytical grade (Sigma Aldrich) NaOH powder was used in the salt roasting experimentsdescribed in this study. Spodumene and NaOH mixtures were roasted in a Thermo ScientificThermolyne Muffle Furnace F30420C 80 using 25 mL zirconium crucibles. Ultrapure deionized water(i.e., resistivity > 18 M cm) was used for all the water leaching experiments, and trace metal gradeacids (i.e., HF, HCl and HNO3) were used for sample digestions for ICP analysis. Three parallel runs,unless specified, were conducted in each experiment, and the confidence intervals of mean valueswere reported.Example 1: One stage roastingAttorney Docket No. 11196 114WO1

[0157] The investigation involved the evaluation of NaOH and spodumene, roasting temperatureand roasting duration. Triplicate experiments were performed, and each experiment was conductedusing 2 g of spodumene. The stoichiometric ratio of NaOH to spodumene was found to be 14:3,equivalent to 1.5:1 by weight.

[0158] It has been shown that certain chemicals exhibit peak roasting efficiencies at their respectivemelting points. A temperature range, including 250 °C, 325 °C, 400 °C, and 600 °C, whichencompasses the melting point of NaOH, was investigated. Experiments were conducted for 5, 30,60, 120, 180 and 240 minutes. For each experiment, after being cooled down to room temperature,the roasted sample was subjected to water leaching. Roasted samples were slightly impacted using apestle in an agate mortar to dismantle any potentially agglomerated particles during roasting. Thewater leaching was performed using 200 g of D.I. water (i.e., spodumene to water ratio of 1%) for 2h at room temperature and a stirring rate of 400 rpm. The leaching experiments were conducted inthree necked round bottom flasks, and the solution was agitated using overhead stirrers. Theleachates were then collected through a 0.45 m hydrophilic polyvinylidene fluoride (PVDF) filter(Durapore® membrane – Millipore Sigma) in a high pressure (700 kPa) filtration setup. The filtercakes were then washed within the filtration unit using 100 g of wash water. The solid residues weredried in a low temperature vacuum oven, weighed, digested, and analyzed along with the leachatesamples for elemental content using ICP AES and ICP MS. Recovery of Li and other elements werecalculated based on the elemental analysis and using Eq. 1:where Ci is the concentration (mg / L) of any element of interest in the leachate with Vi volume (L)and Cs is the elemental content (mg / g) of the element in spodumene concentrate with Ms mass (g)of spodumene sample. The sum of stage 1 and stage 2 leaching elemental recoveries are referred toas the total leaching recovery. Finally, the model free roasting kinetics were determined using aDiscover SDT 650 instrument.

[0159] The impact of water leaching parameters, specifically stirring rate, solid to liquid ratio, andtemperature, on Li recovery was thoroughly investigated. Three parallel experiments wereconducted for each condition, utilizing triplicate samples that had been roasted under theestablished roasting conditions. These experiments were carried out in a consistent environment,employing three necked round bottom flasks with overhead stirrers being used for agitation. Theexperiments were conducted using 200 mL (i.e., 1% spodumene to water ratio) of ultrapure DIwater at room temperature. The Eh and pH of the solutions were determined at the beginning andcompletion of the experiments using a Thermo Scientific pH meter. Furthermore, about 0.5 mLincremental samples were taken out of the solution mixture at 30, 60, 300, 900, 1800, 2700, 5400,Attorney Docket No. 11196 114WO1and 7200 s (i.e., from 30 s to 2 h) for the kinetic study. All the experiments except 100 and 300 rpmwere repeated three times to calculate 95% C.I. for recovery values. To track the concentration ofelements for kinetic study, 1 mL samples were collected incrementally at the duration of theexperiments (i.e., 5, 10, 15, 30, 45, 60, 90, 120, 300, 900, 1800 s). Samples retrieved in all theexperiments were immediately filtered through 0.22 µm using VWR® syringe filters, with the filtratesinstantly acidified with 5% HNO3 to prevent any further reaction. The acidified samples were thenanalyzed for elemental content using ICP analysis. Finally, the reaction kinetics were studied underestablished roasting and leaching conditions.

[0160] To ensure sustainability and environmental compliance, leaching was only carried out usingwater in this study. Therefore, to potentially maximize the recovery of Li, the residue of the initialwater leaching step was oven dried and re roasted with NaOH in different ratios of NaOH to residue(R) (i.e., 0.25:R, 0.5:R, 0.75:R, 1:R, 1.25:R and 1.5:R). The roasted samples were water leached at thepre determined roasting and water leaching conditions to determine the NaOH to stage 1 residueratio.

[0161] Elemental contents of all the leachates were analyzed using the ICP MS at C2M. The mineralphases and morphology of the spodumene concentrate, as well as the leaching residues, wereexamined using X ray diffraction (XRD) and SEM at the Material Characterization Laboratory (MCL)of Penn State’s Materials Research Institute. The XRD data were collected using a MalvernPanalytical Empyrean IV with Cu K radiation ( =1.54056), operated at 45 kV and 40 mA. Thediffractograms were recorded at a scanning rate of 0.06° / second, in the 2 range of 0° to 70°. ForSEM analysis, small amounts of samples were mounted onto sample stubs using carbon tapes andthe samples were coated with Ir for 15 seconds using a Leica Sputter Coater. The images were takenat 5 kV using a Thermo Scientific Verios G4 UC High resolution field emission scanning electronmicroscope (FESEM). The energy dispersive X ray spectroscopy (EDX) mapping was conducted at avoltage of 15 kV in Oxford Instruments EDX with Aztec software. The thermogravimetric analysis(TGA) with simultaneous differential scanning calorimetric (DSC) measurements were performedusing a Discovery SDT 650 instrument at C2M. For this analysis, about 15 mg of material (i.e., 10 mgof NaOH and 5 mg of spodumene concentrate weighed using a Precisa Series 360 EP 125 SemiMicro Balance, Switzerland) was weighed into a platinum (Pt) crucible (110 L). The instrument washeated from room temperature to 400 °C in the modulated mode with a high resolution ramp rateof 2 °C / min. The reaction atmosphere inside the furnace was maintained similar to the roastingenvironment and nitrogen gas was purged at a flow rate of 100 mL / min during the cooling process. Amodulation period of 300 s and a modulation temperature amplitude of ± 1 °C were used for modelfree kinetic analysis and the data were recorded from 50 to 400 °C, after which the weight stabilizes.Attorney Docket No. 11196 114WO1The particle sizes of stage 1 and stage 2 process residues were analyzed in a Malvern PanalyticalMastersizer 3000, using ultrapure deionized water as the suspension medium.

[0162] To further support experimental data and understand the roasting mechanism, the Equilibmodule of FactSage 8.3 was used to develop the roasting chemical reactions. The thermodynamicanalysis was performed by calculating the Gibbs free energy change ( G) of the reactions atoptimum roasting conditions. The solution chemistry and thermodynamics of water leaching wasstudied using HSC Chemistry 10.0.

[0163] The NaOH to spodumene ratio and its effects on Li extraction were studied. The resultsrevealed that the Li extraction increases with the increase of the NaOH to spodumene ratio up to1.5:1 (w / w), resulting in a Li extraction of 77 ± 3.40% (Figure 3). Similar results for Li extraction fromspodumene using K2SO4 roasting at the temperature of 1050 °C, and water leaching have beenreported by others. Further increments of NaOH to spodumene ratio did not have a significanteffect on Li extraction as expected. This is due to the change of products with the amount of NaOHas shown in Figure 4. The formation of less water soluble lithium silicate (Li2SiO3) at low NaOH tospodumene ratio results in lower recovery of Li into solution. However, with the increase of NaOH,the products change to lithium sodium silicate (Li3NaSiO4), which is readily soluble in water.

[0164] The consistent presence of Li3NaSiO4 across the ratios of 1:1 to 1.5:1 suggests a point ofequilibrium in its formation, where further increases in NaOH do not significantly affect itsproduction. Conversely, the decrease in Li3NaSiO4 and the concurrent formation of LiNa(OH)3 atratios exceeding 1.5:1 can be attributed to the theoretically excessive NaOH present in the system.This surplus NaOH might lead to the formation of alternative phases, such as LiNa(OH)3, due to theavailability of excess reactants. This suggests that while other products may form at different ratios,the amount of Li recovered reaches a maximum level at the 1.5:1 ratio.

[0165] Furthermore, the increase of NaOH to spodumene ratio further increased the Al and Siextraction resulting in high impurity content in the product solution (Figure 3). This outcome alignswith the reduction in analcime (NaAlSi2O6 H2O) and keatite (NaAlSi2O6) peaks observed in the XRDspectra (Figure 5), along with the weakening and disappearance of major characteristic peaks ofspodumene, such as those appearing at 19.6° and 31.95° (Figure 5). Furthermore, the X raydiffractograms depicted in Figure 5 for spodumene subjected to NaOH roasting exhibit irregularpatterns with numerous superimposed peaks, highlighting the intricate nature of the roastingprocedure. Moreover, the X ray diffractograms reveal the presence of structurally distorted andamorphous silicate material (i.e., evidenced by peak broadening), alongside the emergence of newcrystalline phases. A NaOH to spodumene ratio of 1.5:1 provides maximum Li extraction (i.e.,Attorney Docket No. 11196 114WO177.00 ± 3.40%), while only 8 ± 0.39% of Al and 47 ± 2.03% of Si are reported to the solution product.This ratio was used in the subsequent experiments.

[0166] The results presented in Figure 6 show that the roasting temperature of 250 °C (i.e., belowthe melting temperature of NaOH ~318 °C) followed by water leaching does not render efficient Liextraction from spodumene, indicated by a low recovery of only 5.00 ± 1.5%.

[0167] The enthalpy and Gibb’s free energy of spodumene reaction with NaOH from 0 °C to 1200°C are shown in Figure 7. Although silica species are very stable, they spontaneously react with alkalicompounds (i.e., G < 0) in the temperature range studied. Moreover, the enthalpy of this alkalisilica reaction changes with temperature due to the formation of different products. However, therates of these reactions at low temperatures are kinetically very slow because breaking the strongcovalent Si–O bonds requires a large amount of energy. At roasting temperatures higher than ~318°C, spodumene behaves differently with a substantial increase in Li recovery of more than 73%(Figure 6). This shows that the reaction of NaOH with spodumene produces readily leachablephases of Li above the melting temperature of NaOH. Specifically, the less water soluble Li2SiO3product formed at low temperatures is not formed above the melting temperature of NaOH due tothe sufficient energy input for the formation of readily water soluble Li3NaSiO4 and LiAl(SiO4) asconfirmed by XRD analysis (Figure 8). Moreover, the importance of roasting temperature in Liextraction from spodumene is directly related to the requirement for elevated temperatures tobreak the intact silicate structure. Consequently, 325 °C was selected as the temperature forroasting in successive experiments as the further increase of temperature above 325 °C did not yieldany significant increase in Li extraction, because the LiAl(SiO4) and Li3NaSiO4 products did not changewith further temperature increase (Figure 8). However, the Si recovery substantially increased withthe increase of roasting temperature due to the promotion of alkali silica reaction at hightemperatures (>325 °C).

[0168] Due to slow reaction kinetics of alkali compounds with silicates to break Si–O bonds, shortroasting durations, such as 5 min, 30 min, and 60 min, did not effectively extract Li fromspodumene as they only yielded 13 ± 0.94%, 56 ± 2.16%, and 68 ± 1.87%, respectively (Figure 9).Reasonably, the ion exchange reactions involving Li and Al in spodumene with Na are alsokinetically slow. This observation is further supported by the TGA analysis as shown in Figure 10.

[0169] The reaction of NaOH with spodumene shows four regions of mass loss (10). The initialmass decrease depicted by region [1] in Figure 10 can be attributed to the loss of moisture mostlyfrom the hygroscopic NaOH in the system. The peak indicated by [2] is due to the melting of NaOH.Following the melting of NaOH in the system, the major reaction initiates, marking the breakage ofSi O bonds indicated by the peak [3] in Figure 8. Additionally, the peak [4] is indicative of the ionAttorney Docket No. 11196 114WO1exchange of Na with Li and Al and reconstructive transformation of (Li) spodumene into keatite(NaAlSi2O6) and analcime (NaAlSi2O6 H2O) (Figure 10). Initially, during the release of Li ions, substoichiometric phases such as Li0.33Al0.33Si0.67O2 and Na0.775Al0.775Si0.225O2 are formed, where Li ions canbe randomly distributed within the lattice structure. The limited solubility of Na ions inLi0.33Al0.33Si0.67O2 arises from the disparities in ionic radii and the interaction with the silicate host.Notably, the larger size of the Na ions compared to the Li ions leads to local expansion of themicaceous spodumene layered structure upon Na insertion, thereby affecting the electrostaticattraction between the negatively charged SiO4 and the positively charged Li layers. Specifically, anincrease in the distance between negatively charged silicates layers weakens the attraction to theincorporated Li ions. It has been postulated that after reaching a certain threshold of Na with Al andLi ion exchange, this mechanism shifts towards reconstructive transformation of (Li) spodumeneinto keatite and analcime. This shift is supported by a decrease in both spodumene and NaOHconcentrations, coinciding with the appearance of keatite and analcime (Figure 8). Therefore, it isevident that Li extraction increases with roasting time for the reaction at 325 °C. In this regard, forroasting duration of 2 h, Li extraction reached 77 ± 1.54%, and the further increase of roasting timefor 3 h and 4 h did not produce a significant difference in Li extraction (Figure 9).

[0170] This observation is also in agreement with the stabilization of mass loss in the TGA curveslightly after 2 h. In addition, the study of reaction kinetics showed that this reaction is characterizedby a fairly high activation energy (Ea) of 212 kJ / mol with a reaction rate of 0.065 mg / min at 325 °Cfurther indicating the need of dwelling time for 2 h. Consequently, the NaOH roasting reaction takesplace at a relatively lower temperature compared to values reported in existing literature whenspodumene reacts with alternative reagents. This highlights a significant advantage of our proposedprocess.

[0171] The thickness of the boundary layer surrounding a solid particle in the lixiviant depends onthe agitation rate. Higher stirring rates lead to an increased shear rate within the solution, resultingin a thinner film layer, promoting diffusion, and enhancing the mass transfer rate through the filmdiffusion layer.

[0172] The solid to liquid (S / L) ratio determines the stoichiometric ratio of reactants, which directlyinfluences the equilibrium of the reaction. The effect of the S / L ratio on the Li leaching recovery wasinvestigated in the range 1% to 20% while maintaining the other leaching parameters constant at 23°C (room temperature) for a duration of 30 minutes (Figure 11).

[0173] The Li recovery did not show any significant difference with the increase of S / L ratio up to10% (Figure 11). However, further increases up to 15% and 20% decreased Li extraction. This isbecause at S / L ratios below 10%, mass transfer limitations cannot significantly impede the effectiveAttorney Docket No. 11196 114WO1interaction of water with solid material, promoting efficient Li recovery. However, a higher ratio canlead to excessive solid particles, by reducing their exposure to water and increasing the pulp densityleading to decreasing Li recovery (Figure 11). In addition, competing reactions due to the complexityof roasting products can further impede Li dissolution. It has been hypothesized that the formationof insoluble reaction products between Si and Li can occur, depositing onto the surface of reactiveaggregate particles. These products are highly likely to serve as a physical barrier, preventing furtherinteraction with siloxane (Si O Si) groups by alkalis. For example, the complex formed between Siand Li, in the presence of LiOH is highly insoluble. Consequently, it creates a coating on the surfaceof reactive silica particles, effectively hindering additional involvement of dissolution reactions.Furthermore, challenges in agitation and mixing at higher S / L ratios can result in non uniformexposure of solid particles to water imposing a barrier for Li dissolution.

[0174] A leaching process that is primarily governed by a chemical reaction at the boundary layer ismore dependent on temperature; whereas, agitation conditions have a more significant effect ondiffusion controlled processes. The effect of temperature on Li recovery during water leaching ofNaOH roasted spodumene was investigated in the range of 10 °C to 90 °C using a stirring rate of100 rpm and S / L ratio of 10% for 30 minutes (Figure 12). Samples were retrieved incrementally atvarious time intervals. Figure 12 shows that dissolution is very sensitive to temperature as itsrecovery significantly decreased with the increase in leaching temperature.

[0175] When the temperature was increased from 10 °C (283 K) to 90 °C (363 K), Li recoverydecreased from 71 ± 5.01% to 27 ± 2.34% after 15 s of the dissolution reaction (Figure 12). Inaddition, Li dissolution appeared to be very sensitive to temperature, indicating that the dissolutionreaction was most likely exothermic. To further understand this phenomenon, the temperaturevariation of the system was monitored throughout the duration of the experiments at different settemperature values. As shown in Figure 12, the dissolution reaction was highly exothermic wherethe temperature of the system suddenly increased above the set value and stabilized at least after 5min. of reaction. This observation was further supported by thermodynamic calculations showingthat the overall reaction of roasted products with water is exothermic ( H < 0) and spontaneous ( G< 0) in the range of temperature studied as shown in Figure 13. In addition, the Gibb’s free energyvalues show that the spontaneity of the reaction decreases with the increase in temperature, furthervalidating the observations.

[0176] Furthermore, the high and low Li recovery values at low and high temperatures,respectively, could also be partly attributed to the negatively charged sites on the particle surfaceattracting cations, resulting in the formation of an electrostatic double layer. Within this structure,the accumulation of Na+ ions at the particle surface, also known as the Stern layer, enhances theAttorney Docket No. 11196 114WO1diffusion of cations inside the particles. This is due to the creation of a more pronouncedconcentration gradient, leading to increased Li recovery at low temperatures. However, when theionic strength of the solution is elevated, the surface charges are shielded, rendering the surfaceselectrically neutral. Consequently, this shielding effect hampers the diffusion of cations toward theparticle surface and within the mineral particles. As a result, the extraction of Li can be reduced athigh temperatures (Figure 12).

[0177] To further understand the prevailing mechanism that is essential in the course of reactordesign and development of downstream purification processes, leaching kinetics were studied.Figure 12 shows that the maximum recovery is reached around 15 s, reflecting rapid reactionkinetics. The water leaching of the NaOH roasted spodumene could be elucidated through theconcept of a heterogeneous reaction occurring at the boundary between the solid roasted particlesand water. Typically, there are two major steps involved in heterogeneous reactions that can berelated to water leaching of NaOH roasted spodumene: (i) diffusion of lixiviant from bulk solutionto the solution boundary layer, and (ii) chemical reaction at the solid liquid interface. However, bothof these mechanisms are significantly faster that they happen within 15 s of the reaction making itpractically difficult to determine the rate limiting step.

[0178] The rapid water leaching kinetics of this method is an advantage, as it also ensures thatleaching kinetics will not be a limiting factor in reactor design. After reaching equilibrium at 15 s, theLi dissolution is restricted due to the mass transfer limitation (i.e., due to the formation of a sodiumaluminum silicate product layer over the unreacted spodumene core) during the roasting reaction.

[0179] As can be seen in Figure 12, the rate apparently becomes slow with the increase oftemperature. According to the fundamentals of reaction kinetics, the rate of reaction increases withthe increase of temperature. However, in this exothermic reaction, the rate of backward reaction(endothermic) is more dominant that the rate of forward reaction (exothermic), by slowing theapparent rate of the forward dissolution reaction with the temperature rise. The faster dissolutionkinetics during the first minute, followed by a slow process, indicate that multiple reactionmechanisms may be in play, a phenomenon that has also been observed in other studies. To explainthe observed behavior in this heterogeneous system, a simplified reaction mechanism is proposed,based on the mineral phases identified in the XRD analysis of the roasted material.

[0180] The proposed mechanism for the dissolution of NaOH roasted spodumene in waterinvolves several key reactions. Initially, Li3NaSiO4 and LiAl(SiO4) dissolve in water, forming LiOH,NaOH, and Si(OH)4. Hydrolysis of Si(OH)4 results in the formation of SiO2 and H2O, whilealuminosilicate complexes formed are simultaneously transformed to more stable compounds. Al³reacts with OH to produce Al(OH)3, and both Li and Na form their respec ve hydroxides.Attorney Docket No. 11196 114WO1Dissolution of other aluminosilicates and the formation of soluble silicate compounds further aid inLi extraction. Finally, these reactions detail the chemical transformations necessary for efficientlybreaking down water soluble phases derived from the NaOH spodumene roasting reaction andextracting Li, emphasizing the importance of controlled reaction conditions to maximize recovery.

[0181] After thorough investigation of the NaOH roasting of spodumene and the subsequent waterleaching process, achieving a Li recovery of only 71 ± 5.01% under optimal process conditions isperplexing. This observation suggests the presence of underlying factors limiting the extractionefficiency.

[0182] To further understand the observations and mechanisms governing the roasting andleaching processes, phase transformations and morphological changes at optimum conditions werestudied using X ray diffraction and scanning electron microscopy (Figure 14). The X raydiffractograms of NaOH roasted spodumene demonstrated in Figure 14b reveal many overlappingpeaks, indicating the complexity of the roasting process. The complexity and increase in mineralphases could be attributed to the substitution reactions (e.g., NaxAlxSi1 xO2 or K1 xAl1 xSixO2 solidsolutions occurring due to the substitution reaction of M+ + Al3+ Si4+ (M = Li, Na, K)) and thepresence of other naturally occurring impurities such as Fe and Ca in spodumene. Additionally, theformation of structurally distorted and amorphous silicate and new crystalline phases during theroasting process can be identified through peak broadening and the emergence of new peaks in theX ray diffractogram.

[0183] The phase transformations of spodumene upon reaction with NaOH were furtherconfirmed by visual changes observed under SEM. The relatively coarse spodumene particles withdistinct corrugated edges and smooth surfaces have changed to irregularly shaped particles due tothe reaction with melted NaOH (Figure 14b and c). Furthermore, EDS analysis verified the chemicalcomposition of the roasted particles are rich in Na, Al, Si and O. In addition, the formation of tinyneedle shaped and almost isometric crystals during roasting, also rich in Na, Al, Si and O, suggest theformation of sodium aluminum silicates (e.g., keatite NaAlSi2O6 and analcime NaAlSi2O6 H2O) andsodium silicates (e.g., Na2SiO3).

[0184] The presence of a few peaks corresponding to unreacted spodumene in the X raydiffractogram suggests that the roasting reaction might not have fully penetrated to the cores ofcoarser particles, by hampering Li recovering. This hypothesis was further supported by the SEM andEDS, where a product layer mainly composed of Na, Al, Si and O formed around the boundary of theunreacted spodumene core was observed. This phenomenon of a particle shrinking core modelduring the roasting process is illustrated in detail using Figure 15 which illustrates the formation of aAttorney Docket No. 11196 114WO1product layer hindering the mass transfer of molten NaOH towards the unreacted spodumenecore. Any remaining NaOH reacts forming Na2SiO3 and Na4SiO4.

[0185] The shrinking core model of NaOH roasting of spodumene was further validated byinvestigating the effect of particle size on elemental recovery. The spodumene concentrate wasground using a Mini Puck Pulverizer (Rocklabs) to obtain a size fraction of top size 53 m, which wasthen roasted and leached. The significantly higher Li recovery from the spodumene powdercompared to that of spodumene concentrate further supported the hypothesized shrinking coremodel. Fine grinding increases the surface area and also exposes more Li containing sites. Thisenhances the reaction of Li with NaOH during roasting, forming products such as LiNaSiO4, which iseventually recovered during water leaching. In contrast, Al and Si are mostly exposed to react withNaOH even without size reduction. Moreover, Al and Si form more stable, less water solublecomplexes such as aluminosilicates. Therefore, the particle size reduction primarily impacts therecovery of Li, while Al and Si recoveries remain largely unaffected. However, spodumene, being aninosilicate, has a relatively high Bond ball mill work index (BBMWI) of 44.9 kWh / t. Therefore, finegrinding of raw spodumene is generally excluded from process flowsheets to avoid extra energyconsumption to enhance process feasibility.

[0186] The water leaching process overcomes this mass transfer limitation by the dissolution ofgenerated water soluble phases on the product layer. This enhances the particle porosity andfacilitates the lixiviant diffusion and recovery of the remaining Li in the residue by other means, suchas acid leaching. The water leaching process involves several simultaneous reactions, driven by themineral composition and the complexity of roasting products. After leaching, the particles exhibitedporous structures on their surfaces, and keatite crystals were also observed to be partially resistantto water leaching. This resistance could be attributed to the low surface concentration of chargedspecies (such as >Si O ) on the particles, which makes keatites crystals less prone to the dissolutionof Al and Si. The dissolution of aluminosilicates, such as keatite and analcime, is incongruent with Altypically leaving the crystal surface at much slower rates than Si. This is also in agreement with thelower elemental recovery of Al compared to that of Si during the water leaching of the roastedproducts. Example 2: Two stage roasting

[0187] To improve Li recovery during water leaching and eliminate the need for sequential acidleaching, a two stage roasting and water leaching method was investigated. In this approach, thelayers generated in the first roasting are removed through water leaching, with the remaining corebeing reacted with NaOH in the second roasting to extract the remaining Li in the second waterleaching.Attorney Docket No. 11196 114WO1

[0188] Effect of NaOH to stage 1 residue ratio: After stage 1 roasting and water leaching, thechemistry of spodumene is significantly changed. The Li containing species in the stage 1 leachresidue is mostly LiAl(SiO4) and spodumene. In addition, this residue also contains keatite,analcime and other silicate products. Figure 16a shows the Li recovery of stage 2 roasting fordifferent ratios of NaOH to stage 1 leaching residue (R), concluding 1:R (with Li recovery of 86 ±3.06% from the R) as the weight ratio of NaOH to stage 1 residue, after which the Li recovery doesnot significantly change. The increase of Si recovery by increasing NaOH was expected due to thefavorability of the alkali silica reaction.

[0189] The Li recovery data presented in Figure 16d revealed that the kinetics of the stage 2roasting is significantly faster than the stage 1 roasting, as the maximum Li recovery (84 ± 3.88%)was obtained within 10 min roasting time. The faster kinetics could be attributed to the significantchange in chemistry and crystal structure. Furthermore, the particle size reduction and deteriorationof the crystal structure during stage 1 facilitates the diffusion of NaOH into the silicate material, byimposing faster kinetics in stage 2 with a reaction rate of 0.078 mg / min at 325 °C compared to thatof 0.065 mg / min in stage 1.

[0190] In stage 2, the leach residue obtained from stage 1 contain a lower concentration of Li andother elements; therefore, a lower solid to liquid ratio was required. In this stage, the Liconcentration is much lower, necessitating a lower S / L ratio to maintain a sufficient concentrationgradient, enhance dissolution, and overcome diffusion limitations to ensure maximum Li recoveryfrom the residue.

[0191] The stirring rate for the second stage water leaching was investigated and found to givemaximal recovery at 200 rpm, after which the recovery values did not significantly change. Thehigher stirring rate in the second stage is justified by the lower concentration of Li in the roastedproduct compared to stage 1. An enhanced stirring rate at 200 rpm helps to better disperse theparticles and improve the contact between the solid particles and the leaching solution, facilitatingmore efficient extraction of the remaining lithium. Additionally, most alkali silicate reactions aregenerally exothermic. This was also observed during the stage 2 leaching process where the Lirecovery decreased with the increase of leaching temperature. However, this phenomenon is not asdominant in stage 2 compared to stage 1 mostly due to the change of chemistry of the stage 2 feedmaterial. The Li dissolution for stage 2 also followed swift kinetics reaching the equilibrium around60 s as shown in Figure 17c. Therefore, in the context of dissolution of NaOH roasted spodumenein water, the reaction involves complex interactions and diffusion effects, where increasingtemperature beyond a certain point hinder the overall reaction rate due to the favorability of thebackward reaction.Attorney Docket No. 11196 114WO1

[0192] Figure 18 shows the Li recovery for different processes parameters. Remarkably, the total Lirecovery reached over 99% at stage 1 optimum conditions and NaOH to stage 1 residue ratio of1.5:1. The process residue (i.e., the residue obtained after stage 2 water leaching) was characterizedusing XRD and SEM EDS. This residue was partially crystalline, characterized by the occurrence of abroad peak from 10° to 40° in the X ray diffractogram. The particles were extremely small androunded as compared to the spodumene feed. This observation was also consistent with theparticle size distribution of process the residue (i.e., d80 = 72.5 m) determined using a MalvernPanalytical Mastersizer. Based on EDS analysis, these particles were determined to be composed ofmainly aluminum silicates and sodium aluminum silicates that are less water soluble. The unreactedspodumene peaks or any peaks corresponding to Li containing species were not detected in theprocess residue, demarcating the complete conversion of spodumene to water soluble phases.These observations confirm that the initial dissolution reaction follows the shrinking core model.Consequently, the overall Li extraction process developed is summarized in Figure 19.

[0193] This study introduces a novel method for lithium extraction from spodumene using lowtemperature NaOH roasting (325 °C), bypassing the traditional high temperature conversion (1100°C) to spodumene and sulfuric acid baking. This environmentally friendly approach convertsspodumene to water soluble phases, achieving 99% Li recovery through two stage roasting andwater leaching. The method significantly reduces the environmental footprint and promotessustainability and economic viability in the Li extraction industry, positioning it as a leadingenvironmentally responsible alternative in the field.

[0194] Figure 19 depicts a process flowsheet, in addition to eliminating high temperaturecalcination and acid baking steps, utilizes room temperature water leaching, which has fast kineticscompared to that of the traditional method. The method proposed in the flowsheet was validatedusing softened water (i.e., not using deionized water). Consequently, the product solution pH isabove 13, which reduces the chemical consumption for the Li purification step. The variation of Ehand pH of water leaching solution during experiments at different temperatures were alsodetermined. The high pH of the product solution can be explained by sodium silicate dissolutionreactions. The reaction of sodium silicate (i.e., formed during the roasting process) with waterregenerates NaOH and LiOH in the solution. These strong bases are then subsequently dissociatedsignificantly releasing OH ions into the product solution resulting in the increase of pH.

[0195] Furthermore, in this complex system, silanol (Si O Si) forma on through protona on ofnonbridging oxygen (NBO) or via the saturation of undercoordinated silica by OH is also expected.The formation of silanol through NBO results in the release of OH to the system, and the formationof silanol through saturation of undercoordinated silica results in the release of H+. Although theseAttorney Docket No. 11196 114WO1two processes are instantaneous, the release of OH can account for the increase of pH in thesystem.

[0196] The reaction of sodium silicate with water is an exothermic reaction and the increase oftemperature results in the decrease of pH due to the low reactivity of species forming OH ion. Thepredominance of lithium sodium silicates exists in a much larger window of pH at high temperatures(e.g., 90 °C) implying that the solubility of lithium sodium silicates decreases with the increase oftemperature. This is also consistent with the elemental concentrations (i.e., low recovery of Li athigh temperature leaching). It has been suggested that the solubility of LiOH is lower in water;however, Li will dissolve at higher pH. In addition, the recovery of Al (i.e., the other major element ofinterest in spodumene) was low (~10%) during water leaching, because Al exists as AlO(OH) in AlH2O system which is not water soluble. The low recovery of Al is a major advantage of NaOHroasting and water leaching of spodumene for direct Li extraction.Example 3: Extraction from lepidolite

[0197] Lumps of raw lepidolite ore from the Lucky Mica Lithium Project in the Arizona pegmatitebelt were provided by an industry partner. In this study, to prepare the sample for the critical metalextraction, the ore sample was first crushed to 3.35 mm top size and ground into a size of 250 m.Then representative samples of the 250 m size fraction (i.e., typical industrial grade feedstockparticle size) were directly used without further beneficiation for the experimentation in this study.The experiments utilized analytical grade NaOH powder (Sigma Aldrich) as the roasting reagent.

[0198] Lepidolite is unique among Li containing minerals due to its notable concentrations of Rb.Quantitative analysis of the X ray diffraction (XRD) pattern showed that the feed sample in this studyconsists of 92% lepidolite, 5% quartz and 3% albite (Figure 20a). This result was supported by thelithium, aluminum, potassium, and silica oxide contents shown in the table below as determined byInductively Coupled Plasma – Atomic Emission Spectroscopic (ICP AES) analysis. The ScanningElectron Microscopic (SEM) image shows lepidolite particles with angular, irregular shapes andrough surfaces, characteristic of crushed and ground materials. The particles exhibit varying sizes(<250 m), with no significant agglomeration (Figure 20a).

[0199] The composition of the lepidolite sample was analyzed by a Thermo Scientific iCAP 7400 ICPAES at the Laboratory for Isotopes and Metals in the Environment (LIME) of The Pennsylvania StateUniversity (Penn State). Lepidolite and NaOH mixtures were roasted in a Thermo ScientificThermolyne Muffle Furnace F30420C 80 using 25 mL zirconium crucibles to convert lepidolite toAttorney Docket No. 11196 114WO1water soluble phases. Representative 2 g fractions of the lepidolite sample were used in thesequential roasting process to recover the monovalent critical elements, Li, Cs, and Rb. Ultrapuredeionized water with a resistivity exceeding 18 M cm was used in the water leaching of roastingproducts. The Eh and pH of the leach solutions were measured using a Thermo Scientific pH meter.The product solutions and the leach residues were separated through a 0.45 m hydrophilicpolyvinylidene fluoride (PVDF) filter (Durapore® membrane – Millipore Sigma) in a high pressure(700 kPa) filtration setup. The filter cakes were then washed within the filtration unit using half theamount of water used to leach. The process conditions are summarized in the table below.

[0200] Additionally, trace metal grade hydrofluoric acid (HF), hydrochloric acid (HCl), and nitric acid(HNO3) were used for sample digestion and dilution purposes during ICP analysis. The recovery (R%)of Li, Cs and Rb were determined using the equation:where Ci represents the concentration (mg / L) of the element in the leachate with Vi volume (L), Csdenotes the elemental content (mg / g) of the element in the lepidolite sample, Ms corresponds tothe mass (g) of the lepidolite sample. Unless otherwise specified, triplicate experiments wereconducted, and the average recovery values were reported.

[0201] The mineral phases and morphology of raw lepidolite, roasting products and the leachingresidues were assessed through XRD and SEM at the Material Characterization Laboratory (MCL) ofPenn State’s Materials Research Institute. XRD data were collected using a Malvern PanalyticalEmpyrean IV instrument with Cu K radiation ( =1.54056), operated at 45 kV and 40 mA, scanning inthe 2 range of 0° to 70° at a rate of 0.06° / second in a continuous operation mode. Prior to SEManalysis, specimens were affixed onto sample stubs using carbon tape and coated with iridium (Ir)for a duration of 15 seconds using a Leica Sputter Coater. Imaging was subsequently conducted at 5kV using a Thermo Scientific Verios G4 UC High resolution field emission scanning electronmicroscope (FESEM). For elemental mapping using energy dispersive X ray spectroscopy (EDX), anOxford Instruments EDX system equipped with Aztec software was employed at 15 kV.Attorney Docket No. 11196 114WO1

[0202] Thermogravimetric analysis (TGA) was conducted to study the roasting reaction using aDiscovery SDT 650 instrument at Penn State MCL. Approximately 50 mg of the sample, comprised of30 mg of NaOH and 20 mg of raw lepidolite, were weighed into a 110 L platinum (Pt) crucible. Theinstrument was programmed to heat the sample at a ramp rate of 2 °C / min from room temperatureto 900 °C under high resolution mode. A continuous flow of air at a rate of 100 mL / min wasmaintained within the furnace during the analysis to mimic the conditions inside the furnace duringexperimentation. The experimental data were collected over the temperature range of 50 to 900 °Cuntil the weight of the sample stabilized.

[0203] Three baseline experiments were carried out to replicate the conventional processingmethods commonly applied to lepidolite ores. These experiments included Na2SO4 roasting at 1000°C followed by water leaching at 85 °C, NaCl and CaCl2 roasting at 850 °C followed by water leachingat 60 °C, and Na2SO4 and CaCl2 roasting at 850 °C followed by water leaching at ambienttemperature. Roasting was carried out for 0.5 h for each experiment to mimic the originalconditions.

[0204] The roasting process forms a readily water soluble lithium sodium silicate (Li3NaSiO4) phase.Moreover, due to the complexity of the roasting process, in addition to partially reacted lepidolite,the XRD analysis of the roasted products shows the formation of lithium aluminum oxide (LiAlSiO4),lithium oxide (Li2O), Li3NaSiO4, lithium metasilicate (Li2SiO3), and ephesite (NaLiAl4(SiO4)2O2(OH)2) asthe Li bearing phases (Figure 20b). However, mineral phases bearing Cs and Rb that can be presentas isomorphic substitutions in the structure of products formed were most likely below thedetection limit of XRD. Furthermore, the dissolution of NaOH and the formation of products werestudied using the SEM imaging on the surface of lepidolite as shown in Figure 20b.

[0205] The reaction of NaOH with lepidolite exhibits four distinct regions of mass loss, clearlydepicted by the derivative thermogravimetric (DTG) curve shown in Figure 21. The initial decrease inmass, represented by region [1], can be attributed to the loss of moisture, primarily from thehygroscopic NaOH present in the system (Figure 21). The peak denoted by [2] mainly corresponds tothe loss of H2O from lepidolite. The onset of NaOH melting and the attack of Na+ on the Si O bondsmost likely corresponds to the DTG peaks denoted by [3] and [4], respectively (Figure 21).Subsequently, lithium sodium silicate (Li3NaSiO4), lithium metasilicate (Li2SiO3), ephesite(NaLiAl4(SiO4)2O2(OH)2), and sodium orthosilicate (Na4SiO4) are formed (Figure 20b), after which theweight stabilizes until around 800 °C, where the mass loss happens due to the evolution of gaseoushydrogen fluoride (HF) ( Go = 1485.4 kJ at 800 °C), and the conversion of remaining lepidolite tospodumene ( LiAlSi2O6) and leucite (KAlSi2O6) above 850 °C. Therefore, high temperature roastingAttorney Docket No. 11196 114WO1methods likely form LiAlSi2O6, resulting in lower Li, Rb and Cs recoveries during subsequent waterand acid leaching steps, unless the excess amount of additives homogeneously mixed with lepidolite.

[0206] The roasted products were subjected to water leaching, and the elemental recoveries werecalculated. Accordingly, 72 ± 5.08% of Li, 98 ± 2.61% of Rb, and 97 ± 1.30% of Cs were recovered tothe product solution (Figure 22).

[0207] The Rb and Cs recoveries are significantly higher than the three baseline methods. The highrecoveries of Rb and Cs can be attributed to their presence as isomorphous substitutions forpotassium (K), within the lepidolite crystal lattice. Therefore, during chemical reactions, these largerions can be more readily replaced by sodium (Na) from the NaOH used in roasting, leading to theirfaster release into solution, while Li remains more strongly retained within the crystal lattice due toits smaller size and different site occupancy.

[0208] The formation of less water soluble phases like lithium silicate (Li2SiO3) and lithium oxide(Li2O) results in the lower recovery of Li into solution. This result is in good agreement with theremaining diffraction peaks corresponding to Li2SiO3 and Li2O observed in the leach residue (Figure20c). Figure 20c also shows the partially retained lepidolite phase even after NaOH roasting andwater leaching, which can be another reason for comparatively lower Li recovery.

[0209] Furthermore, insoluble reaction products can form between Si and Li, depositing onto thesurface of reactive aggregate particles. These products likely act as physical barriers, impedingfurther interaction with siloxane (Si O Si) groups by alkalis. For instance, the complex formedbetween Si and Li in the presence of LiOH (i.e., produced during water leaching) is highly insoluble.Consequently, it forms a coating on the surface of reactive silica particles, effectively obstructingadditional dissolution reactions.

[0210] Based on the solution chemistry study and HSC modelling, the dissolution of NaOH roastedlepidolite is exothermic ( H < 0) and spontaneous ( G < 0). Therefore, it is evident that waterleaching of NaOH roasted lepidolite is more efficient at low temperatures.

[0211] The extraction of Li, Rb, and Cs from lepidolite was successfully investigated through NaOHroasting and water leaching. High recoveries of Rb (98 ± 2.61%) and Cs (97 ± 1.30%) were achieved,along with a 72 ± 5.08% recovery of Li. This process represents a paradigm shift in the extraction ofthese critical metals, offering significant advantages over conventional methods. By operating atlower roasting temperatures, eliminating the generation of hazardous HF gas, and avoiding the useof corrosive acids, the method enhances safety, reduces environmental impact, and lowersoperating costs. Additionally, the prevention of spodumene formation ensures higher extractionyields and improved product quality using simple water leaching.Attorney Docket No. 11196 114WO1ADDITIONAL EMBODIMENTS

[0212] A method, comprising the steps:contacting a lithium containing material with a first roasting agent at a first elevated temperaturefor a first period of time to provide a first water insoluble phase and a first water soluble phase;contacting the first water insoluble phase and first water soluble phase with a first quantity of waterto dissolve the first water soluble phase;separating the first water insoluble phase from the water comprising the first water soluble phase;contacting the separated first water insoluble phase with a second roasting agent at a secondelevated temperature for a second period of time to provide a second water insoluble phase and asecond water soluble phase;contacting the second water insoluble phase and second water soluble phase with a secondquantity of water to dissolve the second water soluble phase;separating the second water insoluble phase from the water comprising the second water solublephase; andrecovering lithium from the first water soluble phase and second water soluble phase;wherein neither the first water insoluble phase nor second water insoluble phase are contactedwith an acid.

[0213] The method of any preceding embodiment, wherein lithium containing material comprisesspodumene, lepidolite, hectorite, jadarite, Li enriched clays, Li batteries, waste streams of miningand processing of coal and coal by products and minerals and oil shale, coal underclay, coaloverburden, recycled materials, or a combination thereof.

[0214] The method of any preceding embodiment, wherein lithium containing material comprisesspodumene.

[0215] The method of any preceding embodiment, wherein the lithium containing material has aparticle size d50 (ASTM C136 01) from 1 1,000 µm, from 10 1,000 µm, from 10 500 µm, from 50 500µm, from 50 250 µm, from 100 250 µm, or from 100 200 µm.

[0216] The method of any preceding embodiment, wherein the lithium containing material has aparticle size d90 (ASTM C136 01) that is no more than 5x the particle size d50 (ASTM C136 01), nomore than 4x the particle size d50 (ASTM C136 01), no more than 3x the particle size d50 (ASTM C13601), or no more than 2x the particle size d50 (ASTM C136 01).

[0217] The method of any preceding embodiment, wherein the lithium containing material furthercomprises aluminum, calcium, iron, silicon, sodium, a rare earth element, or a combination thereof.

[0218] The method of any preceding embodiment, wherein the first roasting agent and lithiumcontaining mineral are present in a weight ratio from 10:1 to 1:10, from 1:1 to 1:10, from 1:1 to 1:5,Attorney Docket No. 11196 114WO1from 2:1 to 1:2, from 10:1 to 1:1, from 5:1 to 1:1, from 3:1 to 1:1, from 2:1 to 1:1, from 1.75 to 1.25,or 1.5:1.

[0219] The method of any preceding embodiment, wherein the first roasting agent and lithiumcontaining mineral are present in a weight ratio from 1.75 to 1.25.

[0220] The method of any preceding embodiment, wherein lithium containing material comprisesspodumene, and the first roasting agent and spodumene are present in a weight ratio from 10:1to 1:10, from 1:1 to 1:10, from 1:1 to 1:5, from 2:1 to 1:2, from 10:1 to 1:1, from 5:1 to 1:1, from 3:1to 1:1, from 2:1 to 1:1, from 1:1.75 to 1:1.25, or 1.5:1.

[0221] The method of any preceding embodiment, wherein lithium containing material comprisesspodumene, and the first roasting agent and spodumene are present in a weight ratio from 1.75to 1.25.

[0222] The method of any preceding embodiment, wherein the first roasting agent comprises analkali metal salt, an alkaline earth metal salt, an ammonium salt, or a combination thereof.

[0223] The method of any preceding embodiment, wherein the first roasting agent comprises analkali hydroxide, alkali carbonate, alkali sulfate, alkali chloride, alkali nitrate, alkaline earthhydroxide, alkaline earth carbonate, alkaline earth sulfate, alkaline earth chloride, alkaline earthnitrate, ammonium hydroxide, ammonium carbonate, ammonium sulfate, ammonium chloride,ammonium nitrate, or a combination thereof.

[0224] The method of any preceding embodiment, wherein the first roasting agent comprisesNaOH, Na2CO3, KOH, K2CO3, MgCO3, CaCO3, BaCO3, NaCl, KCl, CaCl2, MgCl2, NaNO3, KNO3, Ca(NO3)2,Ba(NO3)2, Mg(NO3)2, Ca(OH)2, CaSO4, (NH4)2SO4, Na2SO4, or a combination thereof.

[0225] The method of any preceding embodiment, wherein the first roasting agent comprisesNaOH.

[0226] The method of any preceding embodiment, wherein the first elevated temperature isgreater than the melting point of the first roasting agent.

[0227] The method of any preceding embodiment, wherein the first elevated temperature is from100 800 °C., from 200 800 °C., from 200 700 °C., from 200 600 °C., from 200 500 °C., from 200 400°C., from 250 400 °C., from 250 350 °C., from 200 300 °C., from 300 350 °C., from 300 400 °C., orfrom 350 400 °C.

[0228] The method of any preceding embodiment, wherein the first elevated temperature isprovided by microwave irradiation of the lithium containing material and first roasting agent.

[0229] The method of any preceding embodiment, wherein the first elevated temperature isprovided by microwave irradiation of the lithium containing material and first roasting agent,wherein the microwave source has a frequency between about 900 MHz to about 6 GHz.Attorney Docket No. 11196 114WO1

[0230] The method of any preceding embodiment, wherein the first elevated temperature isprovided by microwave irradiation of the lithium containing material and first roasting agent,wherein the microwave source has an energy from 0.5 30 kW.

[0231] The method of any preceding embodiment, wherein the first period of time is from 0.1 12hours, from 0.5 12 hours, from 1 12 hours, from 0.5 6 hours, from 0.5 3 hours, from 1 2.5 hours,from 1 3 hours, from 2 4 hours, from 1.5 2.5 hours, from 1 5 hours, from 2 10 hours, from 5 10hours or from 6 12 hours.

[0232] The method of any preceding embodiment, wherein the first period of time is from 1.5 2.5hours.

[0233] The method of any preceding embodiment, wherein step (a) is performed at a pressure from0.1 20 MPa.

[0234] The method of any preceding embodiment, wherein the first water insoluble phase and firstwater soluble phase are subjected to size reduction prior to contacting with the first quantity ofwater.

[0235] The method of any preceding embodiment, wherein the first quantity of water is provided ata solids:liquid ratio from 0.1 10 wt.%, from 0.1 5 wt.%, from 0.1 2.5 wt.%, from 0.5 2.5 wt.%, orfrom 0.5 1.5 wt.%, from 1 20 wt.%, from 1 15 wt.%, from 2 10 wt.%, from 2 5 wt.%, from 5 10 wt.%,or from 5 15 wt.%.

[0236] The method of any preceding embodiment, wherein the first quantity of water is provided ata solids:liquid ratio from 5 15 wt.%.

[0237] The method of any preceding embodiment, wherein the lithium containing material isspodumene, and the first quantity of water is provided at a solids:liquid ratio from 0.1 20 wt.%, from0.1 10 wt.%, from 0.1 5 wt.%, from 0.1 2.5 wt.%, from 0.5 2.5 wt.%, from 0.5 1.5 wt.%, from 1 20wt.%, from 1 15 wt.%, from 2 10 wt.%, from 2 5 wt.%, from 5 10 wt.%, from 7.5 12.5 wt.%, or from5 15 wt.%.

[0238] The method of any preceding embodiment, wherein the lithium containing material isspodumene, and the first quantity of water is provided at a solids:liquid ratio from 7.5 12.5 wt.%.

[0239] The method of any preceding embodiment, wherein the first water insoluble phase and firstwater soluble phase are contacted with the first quantity of water for a period from 1 second 1minute, 1 second 60 minutes, 0.1 60 minutes, from 0.1 30 minutes, from 0.1 20 minutes, from 0.110 minutes, from 0.1 5 minutes, from 0.5 2.5 minutes, or from 0.5 1.5 minutes.

[0240] The method of any preceding embodiment, wherein the first water insoluble phase and firstwater soluble phase are contacted with the first quantity of water for a period from 0.5 1.5 minutes.Attorney Docket No. 11196 114WO1

[0241] The method of any preceding embodiment, wherein the first water insoluble phase and firstwater soluble phase are contacted with the first quantity of water at a temperature from 0 50 °C.,from 5 50 °C., from 10 50 °C., 15 50 °C., from 15 40 °C., from 15 30 °C., from 25 50 °C., from 25 40°C., from 25 30 °C., from 20 30 °C., from 30 40 °C., or from 35 50 °C.

[0242] The method of any preceding embodiment, wherein the first water insoluble phase and firstwater soluble phase are contacted with the first quantity of water at a temperature from 20 30 °C.

[0243] The method of any preceding embodiment, wherein the first water insoluble phase and firstwater soluble phase are contacted with the first quantity of water with agitation.

[0244] The method of any preceding embodiment, wherein the first water insoluble phase and firstwater soluble phase are contacted with the first quantity of water using countercurrent leaching.

[0245] The method of any preceding embodiment, wherein the first water insoluble phase and firstwater soluble phase are contacted with the first quantity of water with stirring.

[0246] The method of any preceding embodiment, wherein the first water insoluble phase and firstwater soluble phase are contacted with the first quantity of water with stirring at a rate from 11,200 rpm, from 100 1,200 rpm, from 100 800 rpm, from 100 600 rpm, from 200 600 rpm, from300 500 rpm, from 300 1,200 rpm, from 600 1,200 rpm, from 10 250 rpm, from 50 250 rpm, from50 150 rpm, or from 75 125 rpm.

[0247] The method of any preceding embodiment, wherein the first water insoluble phase and firstwater soluble phase are contacted with the first quantity of water with stirring at a rate from 75 125rpm.

[0248] The method of any preceding embodiment, wherein contacting the first water insolublephase and first water soluble phase with the first quantity of water produces a solution having a pHfrom 10 15, from 11 15, from 11 14, from 12 14, or from 12.5 13.5.

[0249] The method of any preceding embodiment, wherein the first water insoluble phase isseparated from the water comprising the first water soluble phase by filtration.

[0250] The method of any preceding embodiment, wherein the first water insoluble phase isseparated from the water comprising the first water soluble phase by filtration using a filter having amembrane pore size from 0.05 50 µm, from 0.05 25 µm, from 0.05 10 µm, from 0.05 2 µm, from0.1 2 µm, from 0.1 1.5 µm, from 0.1 1 µm, from 0.1 0.5 µm, from 0.25 1 µm, from 0.25 0.5 µm,from 1 10 µm, from 1 5 µm, from 5 25 µm, from 5 50 µm, or from 25 50 µm.

[0251] The method of any preceding embodiment, wherein the separated first water insolublephase is dried prior to being contacted with the second roasting agent.

[0252] The method of any preceding embodiment, wherein the second roasting agent comprises analkali metal salt, an alkaline earth metal salt, an ammonium salt, or a combination thereof.Attorney Docket No. 11196 114WO1

[0253] The method of any preceding embodiment, wherein the second roasting agent comprises analkali hydroxide, alkali carbonate, alkali sulfate, alkali chloride, alkali nitrate, alkaline earthhydroxide, alkaline earth carbonate, alkaline earth sulfate, alkaline earth chloride, alkaline earthnitrate, ammonium hydroxide, ammonium carbonate, ammonium sulfate, ammonium chloride,ammonium nitrate, or a combination thereof.

[0254] The method of any preceding embodiment, wherein the second roasting agent comprisesNaOH, Na2CO3, KOH, K2CO3, MgCO3, CaCO3, BaCO3, NaCl, KCl, CaCl2, MgCl2, NaNO3, KNO3, Ca(NO3)2,Ba(NO3)2, Mg(NO3)2, Ca(OH)2, CaSO4, (NH4)2SO4, Na2SO4, or a combination thereof.

[0255] The method of any preceding embodiment, wherein the second roasting agent comprisesNaOH.

[0256] The method of any preceding embodiment, wherein the second elevated temperature isgreater than the melting point of the second roasting agent.

[0257] The method of any preceding embodiment, wherein the first roasting agent is employed ingreater amount than the second roasting agent.

[0258] The method of any preceding embodiment, wherein the first roasting agent is employed inan amount that is from 100 250%, 100 200%, 100 150%, 100 125%, 125 150%, 125 175%, 150175%, 150 200%, or 175 200% the amount of the second roasting agent.

[0259] The method of any preceding embodiment, wherein the second roasting agent and firstwater insoluble phase are present in a weight ratio from 10:1 to 1:10, from 1:1 to 1:10, from 1:1 to1:5, from 2:1 to 1:2, from 10:1 to 1:1, from 5:1 to 1:1, from 3:1 to 1:1, from 2:1 to 1:1, from 1:1.75 to1:1.25, from 0.1:1 to 1:2, from 0.5:1 to 1:2, from 0.5:1 to 1:1.5, or from 0.75:1 to 1:1.25.

[0260] The method of any preceding embodiment, wherein the first roasting agent and first waterinsoluble phase are present in a weight ratio from 1:0.75 to 1:1.25.

[0261] The method of any preceding embodiment, wherein the second elevated temperature isfrom 100 800 °C., from 200 800 °C., from 200 700 °C., from 200 600 °C., from 200 500 °C., from 200400 °C., from 250 400 °C., from 250 350 °C., from 200 300 °C., from 300 350 °C., from 300 400 °C.,or from 350 400 °C.

[0262] The method of any preceding embodiment, wherein the second elevated temperature isprovided by microwave irradiation or by a heat transfer process, i.e., using a heating mantle or otherheating source, of the first water insoluble phase and second roasting agent.

[0263] The method of any preceding embodiment, wherein the second elevated temperature isprovided by microwave irradiation of the first water insoluble phase and second roasting agent,wherein the microwave source has a frequency between about 900 MHz to about 6 GHz.Attorney Docket No. 11196 114WO1

[0264] The method of any preceding embodiment, wherein the second elevated temperature isprovided by microwave irradiation of the first water insoluble phase and second roasting agent,wherein the microwave source has an energy from 0.5 30 kW.

[0265] The method of any preceding embodiment, wherein the second period of time is less thanthe first period of time.

[0266] The method of any preceding embodiment, wherein the second period of time is from 150%, from 1 25%,from 1 10%, from 1 5%, from 2 10%, from 2 6%, from 5 10%, from 10 25%, from25 50%, or from 25 75% the first period of time.

[0267] The method of any preceding embodiment, wherein the second period of time is from 510% the first period of time.

[0268] The method of any preceding embodiment, wherein the second period of time is from 1second 60 minutes, 0.1 60 minutes, from 1 60 minutes, from 1 30 minutes, from 1 15 minutes, from1 10 minutes, from 1 5 minutes, from 5 15 minutes, from 10 25 minutes, from 10 60 minutes, orfrom 30 60 minutes.

[0269] The method of any preceding embodiment, wherein step (d) is performed at a pressure from0.1 20 MPa.

[0270] The method of any preceding embodiment, wherein the second water insoluble phase andsecond water soluble phase are subjected to size reduction prior to contacting with the secondquantity of water.

[0271] The method of any preceding embodiment, wherein the second quantity of water is greaterthan the first quantity of water.

[0272] The method of any preceding embodiment, wherein the second quantity of water is in anamount from 100 2,000%, from 100 1,000%, from 100 500%, from 100 250%, from 250 750%, from250 500%, from 500 1,000%, from 500 1,500% from 1000 2,000% the first quantity of water.

[0273] The method of any preceding embodiment, wherein the second quantity of water isprovided is provided at a solids:liquid ratio from 0.1 10 wt.%, from 0.1 5 wt.%, from 0.1 2.5 wt.%,from 0.5 2.5 wt.%, from 0.5 1.5 wt.%, from 1 20 wt.%, from 1 15 wt.%, from 2 10 wt.%, from 2 5wt.%, from 5 10 wt.%, or from 5 15 wt.%.

[0274] The method of any preceding embodiment, wherein the second quantity of water isprovided is provided at a solids:liquid ratio from 0.5 2.5 wt.%.

[0275] The method of any preceding embodiment, wherein the second water insoluble phase andsecond water soluble phase are contacted with the second quantity of water for a period from 1second 30 minutes, 0.1 30 minutes, from 0.1 20 minutes, from 1 20 minutes, 2 20 minutes, from 520 minutes, from 5 15 minutes, or from 10 20 minutes.Attorney Docket No. 11196 114WO1

[0276] The method of any preceding embodiment, wherein the second water insoluble phase andsecond water soluble phase are contacted with the second quantity of water for a period from 5 15minutes.

[0277] The method of any preceding embodiment, wherein the second water insoluble phase andsecond water soluble phase are contacted with the second quantity of water at a temperature from0 50 °C., from 5 50 °C., from 10 50 °C., 15 50 °C., from 15 40 °C., from 15 30 °C., from 25 50 °C.,from 25 40 °C., from 25 30 °C., from 20 30 °C., from 30 40 °C., or from 35 50 °C.

[0278] The method of any preceding embodiment, wherein the second water insoluble phase andsecond water soluble phase are contacted with the second quantity of water with agitation.

[0279] The method of any preceding embodiment, wherein the second water insoluble phase andsecond water soluble phase are contacted with the first quantity of water using countercurrentleaching.

[0280] The method of any preceding embodiment, wherein the second water insoluble phase andsecond water soluble phase are contacted with the second quantity of water with stirring.

[0281] The method of any preceding embodiment, wherein the second water insoluble phase andsecond water soluble phase are contacted with the second quantity of water with stirring at a ratefrom 100 1,200 rpm, from 100 800 rpm, from 100 600 rpm, from 100 500 rpm, from 100 250 rpm,from 150 250 rpm, from 200 600 rpm, from 300 500 rpm, from 300 1,200 rpm, or from 600 1,200rpm.

[0282] The method of any preceding embodiment, wherein the second water insoluble phase andsecond water soluble phase are contacted with the second quantity of water with stirring at a ratefrom 150 250 rpm.

[0283] The method of any preceding embodiment, wherein contacting the second water insolublephase and second water soluble phase with the second quantity of water produces a solution havinga pH from 10 15, from 11 15, from 11 14, from 12 14, or from 12.5 13.5.

[0284] The method of any preceding embodiment, wherein the second water insoluble phase isseparated from the water comprising the second water soluble phase by filtration.

[0285] The method of any preceding embodiment, wherein the second water insoluble phase isseparated from the water comprising the second water soluble phase by filtration using a filterhaving a membrane pore size from 0.05 2 µm, from 0.1 2 µm, from 0.1 1.5 µm, from 0.1 1 µm, from0.1 0.5 µm, from 0.25 1 µm, or from 0.25 0.5 µm.

[0286] The method of any preceding embodiment, wherein the first water soluble phase andsecond water soluble phase are combined, and lithium is recovered from the combined phases.

[0287] A method, comprising the steps:Attorney Docket No. 11196 114WO1contacting a material comprising cesium, rubidium, and lithium with a roasting agent at a elevatedtemperature for a period of time to provide a water insoluble phase and a water soluble phase;contacting the water insoluble phase and water soluble phase with a quantity of water to dissolvethe water soluble phase;separating the water insoluble phase from the water comprising the water soluble phase; andrecovering cesium, rubidium, and lithium from the water soluble phase and second water solublephase.

[0288] The method of any preceding embodiment, wherein the material comprising cesium,rubidium, and lithium comprises lepidolite, pollucite, leucite, carnallite, and amblygonite, biotite,recycled materials, or a combination thereof.

[0289] The method of any preceding embodiment, wherein the material comprising cesium,rubidium, and lithium is lepidolite.

[0290] The method of any preceding embodiment, wherein the material comprising cesium,rubidium, and lithium has a particle size d50 (ASTM C136 01) from 1 1,000 µm, from 10 1,000 µm,from 10 500 µm, from 50 500 µm, from 50 250 µm, from 100 250 µm, or from 100 200 µm.

[0291] The method of any preceding embodiment, wherein the material comprising cesium,rubidium, and lithium has a particle size d90 (ASTM C136 01) that is no more than 5x the particle sized50 (ASTM C136 01), no more than 4x the particle size d50 (ASTM C136 01), no more than 3x theparticle size d50 (ASTM C136 01), or no more than 2x the particle size d50 (ASTM C136 01).

[0292] The method of any preceding embodiment, wherein the roasting agent and materialcomprising cesium, rubidium, and lithium are present in a weight ratio from 10:1 to 1:10, from 1:1 to1:10, from 1:1 to 1:5, from 2:1 to 1:2, from 10:1 to 1:1, from 5:1 to 1:1, from 3:1 to 1:1, from 2:1 to1:1, from 1.75 to 1.25, or 1.5:1.

[0293] The method of any preceding embodiment, wherein the roasting agent material comprisingcesium, rubidium, and lithium are present in a weight ratio from 1.75 to 1.25.

[0294] The method of any preceding embodiment, wherein material comprising cesium, rubidium,and lithium comprises lepidolite, and the roasting agent and spodumene are present in a weightratio from 10:1 to 1:10, from 1:1 to 1:10, from 1:1 to 1:5, from 2:1 to 1:2, from 10:1 to 1:1, from 5:1to 1:1, from 3:1 to 1:1, from 2:1 to 1:1, from 1:1.75 to 1:1.25, or 1.5:1.

[0295] The method of any preceding embodiment, wherein material comprising cesium, rubidium,and lithium comprises lepidolite, and the roasting agent and lepidolite are present in a weight ratiofrom 1.75 to 1.25.

[0296] The method of any preceding embodiment, wherein the roasting agent comprises an alkalimetal salt, an alkaline earth metal salt, an ammonium salt, or a combination thereof.Attorney Docket No. 11196 114WO1

[0297] The method of any preceding embodiment, wherein the roasting agent comprises an alkalihydroxide, alkali carbonate, alkali sulfate, alkali chloride, alkali nitrate, alkaline earth hydroxide,alkaline earth carbonate, alkaline earth sulfate, alkaline earth chloride, alkaline earth nitrate,ammonium hydroxide, ammonium carbonate, ammonium sulfate, ammonium chloride, ammoniumnitrate, or a combination thereof.

[0298] The method of any preceding embodiment, wherein the roasting agent comprises NaOH,Na2CO3, KOH, K2CO3, MgCO3, CaCO3, BaCO3, NaCl, KCl, CaCl2, MgCl2, NaNO3, KNO3, Ca(NO3)2,Ba(NO3)2, Mg(NO3)2, Ca(OH)2, CaSO4, (NH4)2SO4, Na2SO4, or a combination thereof.

[0299] The method of any preceding embodiment, wherein the roasting agent comprises NaOH.

[0300] The method of any preceding embodiment, wherein the elevated temperature is greaterthan the melting point of the roasting agent.

[0301] The method of any preceding embodiment, wherein the elevated temperature is from 100800 °C., from 200 800 °C., from 200 700 °C., from 200 600 °C., from 200 500 °C., from 200 400 °C.,from 250 400 °C., from 250 350 °C., from 200 300 °C., from 300 350 °C., from 300 400 °C., or from350 400 °C.

[0302] The method of any preceding embodiment, wherein the elevated temperature is providedby a heat transfer process, i.e., using a heating mantle or other heating source, or microwaveirradiation of the material comprising cesium, rubidium, and lithium and roasting agent.

[0303] The method of any preceding embodiment, wherein the elevated temperature is providedby microwave irradiation of the material comprising cesium, rubidium, and lithium and roastingagent, wherein the microwave source has a frequency between about 900 MHz to about 6 GHz.

[0304] The method of any preceding embodiment, wherein the elevated temperature is providedby microwave irradiation of the material comprising cesium, rubidium, and lithium and roastingagent, wherein the microwave source has an energy from 0.5 30 kW.

[0305] The method of any preceding embodiment, wherein the period of time is from 0.1 12 hours,from 0.5 12 hours, from 1 12 hours, from 0.5 6 hours, from 0.5 3 hours, from 1 2.5 hours, from 1 3hours, from 2 4 hours, from 1.5 2.5 hours, from 1 5 hours, from 2 10 hours, from 5 10 hours or from6 12 hours.

[0306] The method of any preceding embodiment, wherein the period of time is from 1.5 2.5hours.

[0307] The method of any preceding embodiment, wherein step (a) is performed at a pressure from0.1 20 MPa.

[0308] The method of any preceding embodiment, wherein the water insoluble phase and watersoluble phase are subjected to size reduction prior to contacting with the quantity of water.Attorney Docket No. 11196 114WO1

[0309] The method of any preceding embodiment, wherein the quantity of water is provided at asolids:liquid ratio from 0.1 10 wt.%, from 0.1 5 wt.%, from 0.1 2.5 wt.%, from 0.5 2.5 wt.%, or from0.5 1.5 wt.%, from 1 20 wt.%, from 1 15 wt.%, from 2 10 wt.%, from 2 5 wt.%, from 5 10 wt.%, orfrom 5 15 wt.%.

[0310] The method of any preceding embodiment, wherein the quantity of water is provided at asolids:liquid ratio from 5 15 wt.%.

[0311] The method of any preceding embodiment, wherein the material comprising cesium,rubidium, and lithium is lepidolitee, and the quantity of water is provided at a solids:liquid ratio from0.1 20 wt.%, from 0.1 10 wt.%, from 0.1 5 wt.%, from 0.1 2.5 wt.%, from 0.5 2.5 wt.%, from 0.5 1.5wt.%, from 1 20 wt.%, from 1 15 wt.%, from 2 10 wt.%, from 2 5 wt.%, from 5 10 wt.%, from 7.512.5 wt.%, or from 5 15 wt.%.

[0312] The method of any preceding embodiment, wherein the lithium containing material islepidolite, and the quantity of water is provided at a solids:liquid ratio from 7.5 12.5 wt.%.

[0313] The method of any preceding embodiment, wherein the water insoluble phase and watersoluble phase are contacted with the quantity of water for a period from 1 second 6 hours, 1minute 6 hours, 0.1 6 hours, from 1 6 hours, from 1 4 hours, from 1 2 hours, from 1.5 2.5 hours,from 0.1 1 hours, from 0.1 0.5 hours, or from 3 6 hours.

[0314] The method of any preceding embodiment, wherein the water insoluble phase and watersoluble phase are contacted with the quantity of water for a period from 1.5 2.5 hours.

[0315] The method of any preceding embodiment, wherein the water insoluble phase and watersoluble phase are contacted with the quantity of water at a temperature from 0 50 °C., from 5 50°C., from 10 50 °C., 15 50 °C., from 15 40 °C., from 15 30 °C., from 25 50 °C., from 25 40 °C., from25 30 °C., from 20 30 °C., from 30 40 °C., or from 35 50 °C.

[0316] The method of any preceding embodiment, wherein the water insoluble phase and watersoluble phase are contacted with the quantity of water at a temperature from 20 30 °C.

[0317] The method of any preceding embodiment, wherein the water insoluble phase and watersoluble phase are contacted with the quantity of water with agitation.

[0318] The method of any preceding embodiment, wherein the water insoluble phase and watersoluble phase are contacted with the quantity of water with countercurrent leaching.

[0319] The method of any preceding embodiment, wherein the water insoluble phase and watersoluble phase are contacted with the quantity of water with stirring.

[0320] The method of any preceding embodiment, wherein the water insoluble phase and watersoluble phase are contacted with the quantity of water with stirring at a rate from 1 1,200 rpm, from100 1,200 rpm, from 100 800 rpm, from 100 600 rpm, from 200 600 rpm, from 300 500 rpm, fromAttorney Docket No. 11196 114WO1300 1,200 rpm, from 600 1,200 rpm, from 10 250 rpm, from 50 250 rpm, from 50 150 rpm, or from75 125 rpm.

[0321] The method of any preceding embodiment, wherein the water insoluble phase and watersoluble phase are contacted with the quantity of water with stirring at a rate from 300 500 rpm.

[0322] The method of any preceding embodiment, wherein contacting the water insoluble phaseand water soluble phase with the quantity of water produces a solution having a pH from 10 15,from 11 15, from 11 14, from 12 14, or from 12.5 13.5.

[0323] The method of any preceding embodiment, wherein the water insoluble phase is separatedfrom the water comprising the water soluble phase by filtration.

[0324] The method of any preceding embodiment, wherein the water insoluble phase is separatedfrom the water comprising the water soluble phase by filtration using a filter having a membranepore size from 0.05 50 µm, from 0.05 25 µm, from 0.05 10 µm, from 0.05 2 µm, from 0.1 2 µm,from 0.1 1.5 µm, from 0.1 1 µm, from 0.1 0.5 µm, from 0.25 1 µm, from 0.25 0.5 µm, from 1 10 µm,from 1 5 µm, from 5 25 µm, from 5 50 µm, or from 25 50 µm.

[0325] The compositions and methods of the appended claims are not limited in scope by thespecific compositions and methods described herein, which are intended as illustrations of a fewaspects of the claims and any compositions and methods that are functionally equivalent areintended to fall within the scope of the claims. Various modifications of the compositions andmethods in addition to those shown and described herein are intended to fall within the scope ofthe appended claims. Further, while only certain representative compositions and method stepsdisclosed herein are specifically described, other combinations of the compositions and methodsteps also are intended to fall within the scope of the appended claims, even if not specificallyrecited. Thus, a combination of steps, elements, components, or constituents may be explicitlymentioned herein or less, however, other combinations of steps, elements, components, andconstituents are included, even though not explicitly stated. The term “comprising” and variationsthereof as used herein is used synonymously with the term “including” and variations thereof andare open, non limiting terms. Although the terms “comprising” and “including” have been usedherein to describe various embodiments, the terms “consisting essentially of” and “consisting of”can be used in place of “comprising” and “including” to provide for more specific embodiments ofthe invention and are also disclosed. Other than in the examples, or where otherwise noted, allnumbers expressing quantities of ingredients, reaction conditions, and so forth used in thespecification and claims are to be understood at the very least, and not as an attempt to limit theAttorney Docket No. 11196 114WO1application of the doctrine of equivalents to the scope of the claims, to be construed in light of thenumber of significant digits and ordinary rounding approaches

Claims

Attorney Docket No. 11196 114WO1CLAIMSWhat is claimed is:

1. A method, comprising the steps:a) contacting a lithium containing material with a first roasting agent at a first elevatedtemperature for a first period of time to provide a first water insoluble phase and a firstwater soluble phase;b) contacting the first water insoluble phase and first water soluble phase with a firstquantity of water to dissolve the first water soluble phase;c) separating the first water insoluble phase from the water comprising the first watersoluble phase;d) contacting the separated first water insoluble phase with a second roasting agent at asecond elevated temperature for a second period of time to provide a second waterinsoluble phase and a second water soluble phase;e) contacting the second water insoluble phase and second water soluble phase with asecond quantity of water to dissolve the second water soluble phase;f) separating the second water insoluble phase from the water comprising the secondwater soluble phase; andg) recovering lithium from the first water soluble phase and second water soluble phase;wherein neither the first water insoluble phase nor second water insoluble phase are contactedwith an acid.

2. The method of claim 1, wherein lithium containing material comprises spodumene,lepidolite, hectorite, jadarite, Li enriched clays, Li batteries, waste streams of mining andprocessing of coal and coal by products and minerals and oil shale, coal underclay, coaloverburden, recycled materials, or a combination thereof.

3. The method of claim 1, wherein lithium containing material comprises spodumene.

4. The method of claim 1, wherein the lithium containing material has a particle size d50 (ASTMC136 01) from 1 1,000 µm, from 10 1,000 µm, from 10 500 µm, from 50 500 µm, from 50250 µm, from 100 250 µm, or from 100 200 µm.

5. The method of claim 1, wherein the lithium containing material has a particle size d90 (ASTMC136 01) that is no more than 5x the particle size d50 (ASTM C136 01), no more than 4x theAttorney Docket No. 11196 114WO1particle size d50 (ASTM C136 01), no more than 3x the particle size d50 (ASTM C136 01), or nomore than 2x the particle size d50 (ASTM C136 01).

6. The method of claim 1, wherein the lithium containing material further comprisesaluminum, calcium, iron, silicon, sodium, a rare earth element, or a combination thereof.

7. The method of claim 1, wherein the first roasting agent and lithium containing mineral arepresent in a weight ratio from 10:1 to 1:10, from 1:1 to 1:10, from 1:1 to 1:5, from 2:1 to 1:2,from 10:1 to 1:1, from 5:1 to 1:1, from 3:1 to 1:1, from 2:1 to 1:1, from 1.75 to 1.25, or 1.5:1.

8. The method of claim 1, wherein the first roasting agent and lithium containing mineral arepresent in a weight ratio from 1.75 to 1.25.

9. The method of claim 1, wherein lithium containing material comprises spodumene, andthe first roasting agent and spodumene are present in a weight ratio from 10:1 to 1:10,from 1:1 to 1:10, from 1:1 to 1:5, from 2:1 to 1:2, from 10:1 to 1:1, from 5:1 to 1:1, from 3:1to 1:1, from 2:1 to 1:1, from 1:1.75 to 1:1.25, or 1.5:1.

10. The method of claim 1, wherein lithium containing material comprises spodumene, andthe first roasting agent and spodumene are present in a weight ratio from 1.75 to 1.25.

11. The method of claim 1, wherein the first roasting agent comprises an alkali metal salt, analkaline earth metal salt, an ammonium salt, or a combination thereof.

12. The method of claim 1, wherein the first roasting agent comprises an alkali hydroxide, alkalicarbonate, alkali sulfate, alkali chloride, alkali nitrate, alkaline earth hydroxide, alkaline earthcarbonate, alkaline earth sulfate, alkaline earth chloride, alkaline earth nitrate, ammoniumhydroxide, ammonium carbonate, ammonium sulfate, ammonium chloride, ammoniumnitrate, or a combination thereof.

13. The method of claim 1, wherein the first roasting agent comprises NaOH, Na2CO3, KOH,K2CO3, MgCO3, CaCO3, BaCO3, NaCl, KCl, CaCl2, MgCl2, NaNO3, KNO3, Ca(NO3)2, Ba(NO3)2,Mg(NO3)2, Ca(OH)2, CaSO4, (NH4)2SO4, Na2SO4, or a combination thereof.

14. The method of claim 1, wherein the first roasting agent comprises NaOH.

15. The method of claim 1, wherein the first elevated temperature is greater than the meltingpoint of the first roasting agent.

16. The method of claim 1, wherein the first elevated temperature is from 100 800 °C., from200 800 °C., from 200 700 °C., from 200 600 °C., from 200 500 °C., from 200 400 °C., from250 400 °C., from 250 350 °C., from 200 300 °C., from 300 350 °C., from 300 400 °C., orfrom 350 400 °C.Attorney Docket No. 11196 114WO117. The method of claim 1, wherein the first elevated temperature is provided by a heat transferprocess, i.e., using a heating mantle or other heating source, or microwave irradiation of thelithium containing material and first roasting agent.

18. The method of claim 1, wherein the first elevated temperature is provided by microwaveirradiation of the lithium containing material and first roasting agent, wherein themicrowave source has a frequency between about 900 MHz to about 6 GHz.

19. The method of claim 1, wherein the first elevated temperature is provided by microwaveirradiation of the lithium containing material and first roasting agent, wherein themicrowave source has an energy from 0.5 30 kW.

20. The method of claim 1, wherein the first period of time is from 1 second 12 hours, 0.1 12hours, from 0.5 12 hours, from 1 12 hours, from 0.5 6 hours, from 0.5 3 hours, from 1 2.5hours, from 1 3 hours, from 2 4 hours, from 1.5 2.5 hours, from 1 5 hours, from 2 10 hours,from 5 10 hours or from 6 12 hours.

21. The method of claim 1, wherein the first period of time is from 1.5 2.5 hours.

22. The method of claim 1, wherein step (a) is performed at a pressure from 0.1 20 MPa.

23. The method of claim 1, wherein the first water insoluble phase and first water soluble phaseare subjected to size reduction prior to contacting with the first quantity of water.

24. The method of claim 1, wherein the first quantity of water is provided at a solids:liquid ratiofrom 0.1 10 wt.%, from 0.1 5 wt.%, from 0.1 2.5 wt.%, from 0.5 2.5 wt.%, or from 0.5 1.5wt.%, from 1 20 wt.%, from 1 15 wt.%, from 2 10 wt.%, from 2 5 wt.%, from 5 10 wt.%, orfrom 5 15 wt.%.

25. The method of claim 1, wherein the first quantity of water is provided at a solids:liquid ratiofrom 5 15 wt.%.

26. The method of claim 1, wherein the lithium containing material is spodumene, and thefirst quantity of water is provided at a solids:liquid ratio from 0.1 20 wt.%, from 0.1 10 wt.%,from 0.1 5 wt.%, from 0.1 2.5 wt.%, from 0.5 2.5 wt.%, from 0.5 1.5 wt.%, from 1 20 wt.%,from 1 15 wt.%, from 2 10 wt.%, from 2 5 wt.%, from 5 10 wt.%, from 7.5 12.5 wt.%, orfrom 5 15 wt.%.

27. The method of claim 1, wherein the lithium containing material is spodumene, and thefirst quantity of water is provided at a solids:liquid ratio from 7.5 12.5 wt.%.

28. The method of claim 1, wherein the first water insoluble phase and first water soluble phaseare contacted with the first quantity of water for a period from 0.1 60 minutes, from 0.1 30minutes, from 0.1 20 minutes, from 0.1 10 minutes, from 0.1 5 minutes, from 0.5 2.5minutes, or from 0.5 1.5 minutes.Attorney Docket No. 11196 114WO129. The method of claim 1, wherein the first water insoluble phase and first water soluble phaseare contacted with the first quantity of water for a period from 0.5 1.5 minutes.

30. The method of claim 1, wherein the first water insoluble phase and first water soluble phaseare contacted with the first quantity of water at a temperature from 0 50 °C., from 5 50 °C.,from 10 50 °C., 15 50 °C., from 15 40 °C., from 15 30 °C., from 25 50 °C., from 25 40 °C.,from 25 30 °C., from 20 30 °C., from 30 40 °C., or from 35 50 °C.

31. The method of claim 1, wherein the first water insoluble phase and first water soluble phaseare contacted with the first quantity of water at a temperature from 20 30 °C.

32. The method of claim 1, wherein the first water insoluble phase and first water soluble phaseare contacted with the first quantity of water with agitation.

33. The method of claim 1, wherein the first water insoluble phase and first water soluble phaseare contacted with the first quantity of water using countercurrent leaching.

34. The method of claim 1, wherein the first water insoluble phase and first water soluble phaseare contacted with the first quantity of water with stirring.

35. The method of claim 1, wherein the first water insoluble phase and first water soluble phaseare contacted with the first quantity of water with stirring at a rate from 1 1,200 rpm, from100 1,200 rpm, from 100 800 rpm, from 100 600 rpm, from 200 600 rpm, from 300 500rpm, from 300 1,200 rpm, from 600 1,200 rpm, from 10 250 rpm, from 50 250 rpm, from50 150 rpm, or from 75 125 rpm.

36. The method of claim 1, wherein the first water insoluble phase and first water soluble phaseare contacted with the first quantity of water with stirring at a rate from 75 125 rpm.

37. The method of claim 1, wherein contacting the first water insoluble phase and first watersoluble phase with the first quantity of water produces a solution having a pH from 10 15,from 11 15, from 11 14, from 12 14, or from 12.5 13.5.

38. The method of claim 1, wherein the first water insoluble phase is separated from the watercomprising the first water soluble phase by filtration.

39. The method of claim 1, wherein the first water insoluble phase is separated from the watercomprising the first water soluble phase by filtration using a filter having a membrane poresize from 0.05 50 µm, from 0.05 25 µm, from 0.05 10 µm, from 0.05 2 µm, from 0.1 2 µm,from 0.1 1.5 µm, from 0.1 1 µm, from 0.1 0.5 µm, from 0.25 1 µm, from 0.25 0.5 µm, from1 10 µm, from 1 5 µm, from 5 25 µm, from 5 50 µm, or from 25 50 µm.

40. The method of claim 1, wherein the separated first water insoluble phase is dried prior tobeing contacted with the second roasting agent.Attorney Docket No. 11196 114WO141. The method of claim 1, wherein the second roasting agent comprises an alkali metal salt, analkaline earth metal salt, an ammonium salt, or a combination thereof.

42. The method of claim 1, wherein the second roasting agent comprises an alkali hydroxide,alkali carbonate, alkali sulfate, alkali chloride, alkali nitrate, alkaline earth hydroxide, alkalineearth carbonate, alkaline earth sulfate, alkaline earth chloride, alkaline earth nitrate,ammonium hydroxide, ammonium carbonate, ammonium sulfate, ammonium chloride,ammonium nitrate, or a combination thereof.

43. The method of claim 1, wherein the second roasting agent comprises NaOH, Na2CO3, KOH,K2CO3, MgCO3, CaCO3, BaCO3, NaCl, KCl, CaCl2, MgCl2, NaNO3, KNO3, Ca(NO3)2, Ba(NO3)2,Mg(NO3)2, Ca(OH)2, CaSO4, (NH4)2SO4, Na2SO4, or a combination thereof.

44. The method of claim 1, wherein the second roasting agent comprises NaOH.

45. The method of claim 1, wherein the second elevated temperature is greater than themelting point of the second roasting agent.

46. The method of claim 1, wherein the first roasting agent is employed in greater amount thanthe second roasting agent.

47. The method of claim 1, wherein the first roasting agent is employed in an amount that isfrom 100 250%, 100 200%, 100 150%, 100 125%, 125 150%, 125 175%, 150 175%, 150200%, or 175 200% the amount of the second roasting agent.

48. The method of claim 1, wherein the second roasting agent and first water insoluble phaseare present in a weight ratio from 10:1 to 1:10, from 1:1 to 1:10, from 1:1 to 1:5, from 2:1 to1:2, from 10:1 to 1:1, from 5:1 to 1:1, from 3:1 to 1:1, from 2:1 to 1:1, from 1:1.75 to 1:1.25,from 0.1:1 to 1:2, from 0.5:1 to 1:2, from 0.5:1 to 1:1.5, or from 0.75:1 to 1:1.25.

49. The method of claim 1, wherein the first roasting agent and first water insoluble phase arepresent in a weight ratio from 1:0.75 to 1:1.25.

50. The method of claim 1, wherein the second elevated temperature is from 100 800 °C., from200 800 °C., from 200 700 °C., from 200 600 °C., from 200 500 °C., from 200 400 °C., from250 400 °C., from 250 350 °C., from 200 300 °C., from 300 350 °C., from 300 400 °C., orfrom 350 400 °C.

51. The method of claim 1, wherein the second elevated temperature is provided by a heattransfer process, i.e., using a heating mantle or other heating source, or microwaveirradiation of the first water insoluble phase and second roasting agent.

52. The method of claim 1, wherein the second elevated temperature is provided by microwaveirradiation of the first water insoluble phase and second roasting agent, wherein themicrowave source has a frequency between about 900 MHz to about 6 GHz.Attorney Docket No. 11196 114WO153. The method of claim 1, wherein the second elevated temperature is provided by microwaveirradiation of the first water insoluble phase and second roasting agent, wherein themicrowave source has an energy from 0.5 30 kW.

54. The method of claim 1, wherein the second period of time is less than the first period oftime.

55. The method of claim 1, wherein the second period of time is from 1 50%, from 1 25%,from1 10%, from 1 5%, from 2 10%, from 2 6%, from 5 10%, from 10 25%, from 25 50%, or from25 75% the first period of time.

56. The method of claim 1, wherein the second period of time is from 5 10% the first period oftime.

57. The method of claim 1, wherein the second period of time is from 0.1 60 minutes, from 1 60minutes, from 1 30 minutes, from 1 15 minutes, from 1 10 minutes, from 1 5 minutes, from5 15 minutes, from 10 25 minutes, from 10 60 minutes, or from 30 60 minutes.

58. The method of claim 1, wherein step (d) is performed at a pressure from 0.1 20 MPa.

59. The method of claim 1, wherein the second water insoluble phase and second water solublephase are subjected to size reduction prior to contacting with the second quantity of water.

60. The method of claim 1, wherein the second quantity of water is greater than the firstquantity of water.

61. The method of claim 1, wherein the second quantity of water is in an amount from 1002,000%, from 100 1,000%, from 100 500%, from 100 250%, from 250 750%, from 250 500%,from 500 1,000%, from 500 1,500% from 1000 2,000% the first quantity of water.

62. The method of claim 1, wherein the second quantity of water is provided is provided at asolids:liquid ratio from 0.1 10 wt.%, from 0.1 5 wt.%, from 0.1 2.5 wt.%, from 0.5 2.5 wt.%,from 0.5 1.5 wt.%, from 1 20 wt.%, from 1 15 wt.%, from 2 10 wt.%, from 2 5 wt.%, from 510 wt.%, or from 5 15 wt.%.

63. The method of claim 1, wherein the second quantity of water is provided is provided at asolids:liquid ratio from 0.5 2.5 wt.%.

64. The method of claim 1, wherein the second water insoluble phase and second water solublephase are contacted with the second quantity of water for a period from 1 second 30minutes, 0.1 30 minutes, from 0.1 20 minutes, from 1 20 minutes, 2 20 minutes, from 5 20minutes, from 5 15 minutes, or from 10 20 minutes.

65. The method of claim 1, wherein the second water insoluble phase and second water solublephase are contacted with the second quantity of water for a period from 5 15 minutes.Attorney Docket No. 11196 114WO166. The method of claim 1, wherein the second water insoluble phase and second water solublephase are contacted with the second quantity of water at a temperature from 0 50 °C., from5 50 °C., from 10 50 °C., 15 50 °C., from 15 40 °C., from 15 30 °C., from 25 50 °C., from 2540 °C., from 25 30 °C., from 20 30 °C., from 30 40 °C., or from 35 50 °C.

67. The method of claim 1, wherein the second water insoluble phase and second water solublephase are contacted with the second quantity of water with agitation.

68. The method of claim 1, wherein the second water insoluble phase and second water solublephase are contacted with the first quantity of water using countercurrent leaching.

69. The method of claim 1, wherein the second water insoluble phase and second water solublephase are contacted with the second quantity of water with stirring.

70. The method of claim 1, wherein the second water insoluble phase and second water solublephase are contacted with the second quantity of water with stirring at a rate from 100 1,200rpm, from 100 800 rpm, from 100 600 rpm, from 100 500 rpm, from 100 250 rpm, from150 250 rpm, from 200 600 rpm, from 300 500 rpm, from 300 1,200 rpm, or from 600 1,200rpm.

71. The method of claim 1, wherein the second water insoluble phase and second water solublephase are contacted with the second quantity of water with stirring at a rate from 150 250rpm.

72. The method of claim 1, wherein contacting the second water insoluble phase and secondwater soluble phase with the second quantity of water produces a solution having a pH from10 15, from 11 15, from 11 14, from 12 14, or from 12.5 13.5.

73. The method of claim 1, wherein the second water insoluble phase is separated from thewater comprising the second water soluble phase by filtration.

74. The method of claim 1, wherein the second water insoluble phase is separated from thewater comprising the second water soluble phase by filtration using a filter having amembrane pore size from 0.05 2 µm, from 0.1 2 µm, from 0.1 1.5 µm, from 0.1 1 µm, from0.1 0.5 µm, from 0.25 1 µm, or from 0.25 0.5 µm.

75. The method of claim 1, wherein the first water soluble phase and second water solublephase are combined, and lithium is recovered from the combined phases.

76. A method, comprising the steps:a) contacting a material comprising cesium, rubidium, and lithium with a roasting agent ata elevated temperature for a period of time to provide a water insoluble phase and awater soluble phase;Attorney Docket No. 11196 114WO1b) contacting the water insoluble phase and water soluble phase with a quantity of waterto dissolve the water soluble phase;c) separating the water insoluble phase from the water comprising the water solublephase; andd) recovering cesium, rubidium, and lithium from the water soluble phase and secondwater soluble phase.

77. The method of claim 76, wherein the material comprising cesium, rubidium, and lithiumcomprises lepidolite, pollucite, leucite, carnallite, and amblygonite, biotite, recycledmaterials, or a combination thereof.

78. The method of claim 76, wherein the material comprising cesium, rubidium, and lithiumcomprises lepidolite.

79. The method of claim 76, wherein the material comprising cesium, rubidium, and lithium hasa particle size d50 (ASTM C136 01) from 1 1,000 µm, from 10 1,000 µm, from 10 500 µm,from 50 500 µm, from 50 250 µm, from 100 250 µm, or from 100 200 µm.

80. The method of claim 76, wherein the material comprising cesium, rubidium, and lithium hasa particle size d90 (ASTM C136 01) that is no more than 5x the particle size d50 (ASTM C13601), no more than 4x the particle size d50 (ASTM C136 01), no more than 3x the particle sized50 (ASTM C136 01), or no more than 2x the particle size d50 (ASTM C136 01).

81. The method of claim 76, wherein the roasting agent and material comprising cesium,rubidium, and lithium are present in a weight ratio from 10:1 to 1:10, from 1:1 to 1:10, from1:1 to 1:5, from 2:1 to 1:2, from 10:1 to 1:1, from 5:1 to 1:1, from 3:1 to 1:1, from 2:1 to 1:1,from 1.75 to 1.25, or 1.5:1.

82. The method of claim 76, wherein the roasting agent material comprising cesium, rubidium,and lithium are present in a weight ratio from 1.75 to 1.25.

83. The method of claim 76, wherein material comprising cesium, rubidium, and lithiumcomprises lepidolite, and the roasting agent and spodumene are present in a weight ratiofrom 10:1 to 1:10, from 1:1 to 1:10, from 1:1 to 1:5, from 2:1 to 1:2, from 10:1 to 1:1, from5:1 to 1:1, from 3:1 to 1:1, from 2:1 to 1:1, from 1:1.75 to 1:1.25, or 1.5:1.

84. The method of claim 76, wherein material comprising cesium, rubidium, and lithiumcomprises lepidolite, and the roasting agent and lepidolite are present in a weight ratio from1.75 to 1.25.

85. The method of claim 76, wherein the roasting agent comprises an alkali metal salt, analkaline earth metal salt, an ammonium salt, or a combination thereof.Attorney Docket No. 11196 114WO186. The method of claim 76, wherein the roasting agent comprises an alkali hydroxide, alkalicarbonate, alkali sulfate, alkali chloride, alkali nitrate, alkaline earth hydroxide, alkaline earthcarbonate, alkaline earth sulfate, alkaline earth chloride, alkaline earth nitrate, ammoniumhydroxide, ammonium carbonate, ammonium sulfate, ammonium chloride, ammoniumnitrate, or a combination thereof.

87. The method of claim 76, wherein the roasting agent comprises NaOH, Na2CO3, KOH, K2CO3,MgCO3, CaCO3, BaCO3, NaCl, KCl, CaCl2, MgCl2, NaNO3, KNO3, Ca(NO3)2, Ba(NO3)2, Mg(NO3)2,Ca(OH)2, CaSO4, (NH4)2SO4, Na2SO4, or a combination thereof.

88. The method of claim 76, wherein the roasting agent comprises NaOH.

89. The method of claim 76, wherein the elevated temperature is greater than the melting pointof the roasting agent.

90. The method of claim 76, wherein the elevated temperature is from 100 800 °C., from 200800 °C., from 200 700 °C., from 200 600 °C., from 200 500 °C., from 200 400 °C., from 250400 °C., from 250 350 °C., from 200 300 °C., from 300 350 °C., from 300 400 °C., or from350 400 °C.

91. The method of claim 76, wherein the elevated temperature is provided by a heat transferprocess, i.e., using a heating mantle or other heating source, or microwave irradiation of thematerial comprising cesium, rubidium, and lithium and roasting agent.

92. The method of claim 76, wherein the elevated temperature is provided by microwaveirradiation of the material comprising cesium, rubidium, and lithium and roasting agent,wherein the microwave source has a frequency between about 900 MHz to about 6 GHz.

93. The method of claim 76, wherein the elevated temperature is provided by microwaveirradiation of the material comprising cesium, rubidium, and lithium and roasting agent,wherein the microwave source has an energy from 0.5 30 kW.

94. The method of claim 76, wherein the period of time is from 1 second 12 hours, 0.1 12 hours,from 0.5 12 hours, from 1 12 hours, from 0.5 6 hours, from 0.5 3 hours, from 1 2.5 hours,from 1 3 hours, from 2 4 hours, from 1.5 2.5 hours, from 1 5 hours, from 2 10 hours, from5 10 hours or from 6 12 hours.

95. The method of claim 76, wherein the period of time is from 1.5 2.5 hours.

96. The method of claim 76, wherein step (a) is performed at a pressure from 0.1 20 MPa.

97. The method of claim 76, wherein the water insoluble phase and water soluble phase aresubjected to size reduction prior to contacting with the quantity of water.

98. The method of claim 76, wherein the quantity of water is provided at a solids:liquid ratiofrom 0.1 10 wt.%, from 0.1 5 wt.%, from 0.1 2.5 wt.%, from 0.5 2.5 wt.%, or from 0.5 1.5Attorney Docket No. 11196 114WO1wt.%, from 1 20 wt.%, from 1 15 wt.%, from 2 10 wt.%, from 2 5 wt.%, from 5 10 wt.%, orfrom 5 15 wt.%.

99. The method of claim 76, wherein the quantity of water is provided at a solids:liquid ratiofrom 5 15 wt.%.

100. The method of claim 76, wherein the material comprising cesium, rubidium, and lithium islepidolitee, and the quantity of water is provided at a solids:liquid ratio from 0.1 20 wt.%,from 0.1 10 wt.%, from 0.1 5 wt.%, from 0.1 2.5 wt.%, from 0.5 2.5 wt.%, from 0.5 1.5 wt.%,from 1 20 wt.%, from 1 15 wt.%, from 2 10 wt.%, from 2 5 wt.%, from 5 10 wt.%, from 7.512.5 wt.%, or from 5 15 wt.%.

101. The method of claim 76, wherein the lithium containing material is lepidolite, and thequantity of water is provided at a solids:liquid ratio from 7.5 12.5 wt.%.

102. The method of claim 76, wherein the water insoluble phase and water soluble phase arecontacted with the quantity of water for a period from 1 second 6 hours, 1 minute 6 hours,0.1 6 hours, from 1 6 hours, from 1 4 hours, from 1 2 hours, from 1.5 2.5 hours, from 0.1 1hours, from 0.1 0.5 hours, or from 3 6 hours.

103. The method of claim 76, wherein the water insoluble phase and water soluble phase arecontacted with the quantity of water for a period from 1.5 2.5 hours.

104. The method of claim 76, wherein the water insoluble phase and water soluble phase arecontacted with the quantity of water at a temperature from 0 50 °C., from 5 50 °C., from 1050 °C., 15 50 °C., from 15 40 °C., from 15 30 °C., from 25 50 °C., from 25 40 °C., from 25 30°C., from 20 30 °C., from 30 40 °C., or from 35 50 °C.

105. The method of claim 76, wherein the water insoluble phase and water soluble phase arecontacted with the quantity of water at a temperature from 20 30 °C.

106. The method of claim 76, wherein the water insoluble phase and water soluble phase arecontacted with the quantity of water with agitation.

107. The method of claim 76, wherein the water insoluble phase and water soluble phase arecontacted with the quantity of water with countercurrent leaching.

108. The method of claim 76, wherein the water insoluble phase and water soluble phase arecontacted with the quantity of water with stirring.

109. The method of claim 76, wherein the water insoluble phase and water soluble phase arecontacted with the quantity of water with stirring at a rate from 1 1,200 rpm, from 1001,200 rpm, from 100 800 rpm, from 100 600 rpm, from 200 600 rpm, from 300 500 rpm,from 300 1,200 rpm, from 600 1,200 rpm, from 10 250 rpm, from 50 250 rpm, from 50 150rpm, or from 75 125 rpm.Attorney Docket No. 11196 114WO1110. The method of claim 77, wherein the water insoluble phase and water soluble phase arecontacted with the quantity of water with stirring at a rate from 300 500 rpm.

111. The method of claim 77, wherein contacting the water insoluble phase and water solublephase with the quantity of water produces a solution having a pH from 10 15, from 11 15,from 11 14, from 12 14, or from 12.5 13.5.

112. The method of claim 77, wherein the water insoluble phase is separated from the watercomprising the water soluble phase by filtration.

113. The method of claim 77, wherein the water insoluble phase is separated from the watercomprising the water soluble phase by filtration using a filter having a membrane pore sizefrom 0.05 50 µm, from 0.05 25 µm, from 0.05 10 µm, from 0.05 2 µm, from 0.1 2 µm, from0.1 1.5 µm, from 0.1 1 µm, from 0.1 0.5 µm, from 0.25 1 µm, from 0.25 0.5 µm, from 1 10µm, from 1 5 µm, from 5 25 µm, from 5 50 µm, or from 25 50 µm.