WO2025207753A1

WO2025207753A1 - Calcination free extraction and refinement of lithium compounds reduced temperatures utilizing flexible feedstock

Info

Publication number: WO2025207753A1
Application number: PCT/US2025/021520
Authority: WO
Inventors: Brian Christopher KEENUM
Original assignee: Lithium Technologies LLC
Current assignee: Lithium Technologies LLC
Priority date: 2024-03-26
Filing date: 2025-03-26
Publication date: 2025-10-02
Anticipated expiration: 2026-09-26

Abstract

A lithium extraction process and system that extracts lithium from flexible feed stock, including ore-grade targeted deposits and waste rock, is presented. Waste rock corresponds to mine tailings and/or rock that was mined but not used for lithium extraction. Aspects of the process include crushing the source material, structurally decomposing/altering the source material to expose the contained lithium for extraction, leaching the lithium from the structurally decomposes source material, extracting the leached lithium (as a lithium slurry, i.e., lithium carbonate), and drying the leached lithium as one or more commercially useful lithium compounds. Components of the system, such as the concentration, decomposing, leaching and production modules may be implemented as mobile modules that are co-located in situ with the source material.

Description

Calcination Free Extraction and Refinement of Lithium Compounds

Reduced Temperatures Utilizing Flexible Feedstock

BACKGROUND OF THE INVENTION

[0001] Lithium has become a key mineral throughout the world due to its critical role in powering mobile phones, computers, power tools, battery storage of energy generated from wind and solar power, and electric vehicles. Indeed, lithium (Li) is the lightest alkaline metal in the periodic table with a soft texture, silver-white color, high inflammability, and high reactivity. Given its exceptional chemical and physical properties, lithium has been widely used in the manufacture of batteries. Currently, lithium is viewed as the best material/mineral on which to base a battery, particularly a lithium-ion battery, due to its various unique properties. These properties include high energy density, and a reduced risk of thermal runaway as compared to other minerals used as a base in batteries. Lithium has become the most important element in rechargeable battery chemistries worldwide.

[0002] As a counterpoint to all the potential and promise of using lithium for low- carbon power storage and use throughout the world, there is a limited amount of lithium refining capacity available worldwide. Current estimates as to the amount of currently known world-wide lithium reserves vary widely: somewhere between 14 and 80 million metric tons, with approximately 9.1 million metric tons identified in the United States. However, whether the actual amount is closer to 14 or 80 million metric tons, there is a premium on lithium as it is still relatively scarce. This premium is further exacerbated by many factors, including hurdles in provisioning and permitting new mines, as well as the capital-heavy proposition of scaling and operating lithium refining operations.

[0003] Current processes for "harvesting" lithium from the earth include mining for lithium-containing rock or evaporating brine solutions that contain lithium that are pumped from deposits in the earth. The "mining process" involves drilling and blasting to break apart hard rock in which lithium is found, extracting that rock from the mine, chemical leaching the extracted rock using high heat and strong acids (below 6 pH) to separate the lithium from the rock, separating the lithium solution from the non-lithium solid residues, and purifying the lithium solution. The advantage of the mining process is the relatively short timeline for refining battery-grade lithium from hard rock spodumene, LiAlfSiC h, in comparison to evaporating brine solutions containing lithium.

[0004] It should be appreciated that commercially viable lithium mining only occurs on hard rock spodumene and pegmatite deposits that contain, at a minimum, between 1 and 2% lithium. Unfortunately, commercial mining techniques leave a substantial amount of the world's lithium untapped, including lithium is found in "waste rock." "Waste rock" refers to material that was extracted in a mining operation but left unprocessed due to lower concentrations of lithium, or sometimes because lithium was not targeted in the mining process at all.

[0005] Additionally, and perhaps beyond leaving some lithium "unharvested," mining can have a very significant negative impact on the environment. Similarly, the energy costs for using high heat decomposition methods (i.e., calcination) to extract lithium from its source material, and the environmental concerns of the used strong acid solutions to leach the lithium from its source material, also present significant negative impacts on the environment. In short, the environmental scars from mining and the chemicals used to isolate the lithium pose environmental hazards. Disposal of acids, used to leach lithium from its source material, are difficult to dispose of, and disposal is costly when properly executed.

[0006] The brining process mentioned above is limited to a limited number of regions where lithium-laced brine solutions can be produced and have sufficient land available to evaporate those solutions. To extract the lithium from these sources, the lithium-bearing brine solutions are evaporated over time (typically months) to create a concentrated lithium brine solution. The lithium solution is purified and then crystalized by heat to create usable lithium compounds. This evaporation process, like the mining process, poses significant negative environmental concerns. For example, these brine operations begin with utilizing an incredibly large amount of fresh water, placing extreme demands on limited water resources in the areas of the world where lithium-laced brine solutions can be found. In use, the evaporation pools leach substances, including toxic chemicals found in the brine, into the ground/environment. On top of this, the yield of concentrated lithium extracted through evaporation is significantly less than through mining: lithium in brine is measured in parts per billion, rather than in substantial percentages found in hard rock deposits.

SUMMARY OF THE INVENTION

[0007] According to aspects of the disclosed subject matter, a lithium extraction system and process, particularly suitable for extracting lithium from flexible feed stock is presented. Waste rock corresponds to mine tailings and/or rock that was mined but not used for lithium extraction. Aspects of the process include crushing the source material, structurally decomposing/altering the source material to expose the contained lithium for extraction, leaching the lithium from the structurally decomposes source material, extracting the leached lithium (as a lithium slurry, i.e., lithium carbonate), and drying the leached lithium as one or more commercially useful lithium compounds. Components of the system, such as the concentration, decomposing, leaching and production modules may be implemented as mobile modules that are co-located in situ with the source material.

[0008] In accordance with at least one embodiment of the disclosed subject matter, a process for extracting lithium from source material is presented. Indeed, as part of this novel process, a first step is with respect to concentrating the source material to lithium-containing source material. This first step includes crushing the source material to a desired dimension and dissociating lithium- containing source material from crushed non-lithium-containing source material. With the non-lithium-containing source material discarded, a next step is treating the crushed lithium-containing source material to expose the lithium held within for leaching. This step includes, by way of illustration and not limitation, immersing the crushed lithium-containing source material into a heated decomposition bath for a first predetermined period of time. This bath at least partially structurally decomposes the immersed source material, thereby exposing the lithium held within the structurally decomposed source material. The structurally decomposed source material is removed from the decomposition bath and washed to remove the compounds of the bath from the structurally decomposed source material. A subsequent step of the extraction process is a leaching step, i.e., immersing the structurally decomposed source material in a leaching bath for a second predetermined period of time to leach the lithium from the structurally decomposed source material. This leaching results in a lithium slurry extracted from the structurally decomposed source material. After extracting the lithium slurry from the leaching bath, a formulation and drying process is carried out to transform the lithium slurry into a commercially usable lithium compound.

[0009] In accordance with at least one additional embodiment of the disclosed subject matter, a lithium extraction system for extracting lithium from source material is presented. The lithium extraction system includes, at least and without limitation, one or more concentration modules, one or more decomposition modules, one or more leaching modules, and one or more production modules. In operation, a concentration module crushes the source material to a desired dimension, e.g., 50_km to 80^. The concentration module further separates crushed lithium-containing source material from crushed non- lithium-containing source material, such that only the crushed lithium-containing source material is further processed. A decomposition module immerses the crushed lithium-containing source material into a heated decomposition bath, where it remains for a first period of time. The heated decomposition bath partially structurally decomposes (or structurally alters) the immersed source material, thereby exposing the lithium, held within the source material, for extraction. From the bath, the partially structurally decomposed source material is extracted for further processing. A leaching module immerses the structurally decomposed source material in a leaching bath which is mildly acidic, for a second predetermined period of time. This second predetermined period of time is typically much shorter than the first period of time, e.g., one hour vs 24 hours. A lithium slurry leaches out of the source material and forms a lithium compound slurry. The leaching module then extracts the lithium slurry from the leaching bath for further processing. A production module, depending on the final product that is desired, mixes the lithium slurry with one or more additional compound and dries the lithium slurry to a form a commercially usable lithium compound.

[0010] It should be further appreciated that while the lithium extraction system and process are highly suitable for capturing lithium from waste rock, this system/process may also be advantageously and suitably applied to processing hard rock, e.g., mined spodumene.

BRIEF DESCRIPTION OF DRAWINGS

[0011] The detailed description is described with reference to the accompanying figures. In the figures, the same reference numbers in different figures indicate similar or identical items.

[0012] Figure 1 is a process diagram illustrating exemplary elements of a lithium extraction process, formed in accordance with aspects of the disclosed subject matter;

[0013] Figure 2 is a block diagram pictorially illustrating various elements of a lithium extraction process implemented in accordance with aspects of the disclosed subject matter;

[0014] Figure 3 is a process diagram illustrating exemplary elements of a concentration and separation step of the lithium extraction process, in accordance with aspects of the disclosed subject matter;

[0015] Figure 4 is a process diagram illustrating exemplary elements of a decomposition process of the overall lithium extraction process, in accordance with aspects of the disclosed subject matter;

[0016] Figure 5 is a process diagram illustrating exemplary steps of a leaching process, of overall the lithium extraction process, in accordance with aspects of the disclosed subject matter; and

[0017] Figure 6 is a process diagram illustrating exemplary steps of the product generation step of the lithium extraction process, in accordance with aspects of the disclosed subject matter. DETAILED DESCRIPTION OF THE INVENTION

[0018] By way of definition, and as indicated above, the phrase "waste rock" refers to material that was harvested in a mining operation but left unprocessed due to lower concentrations of lithium, or alternatively because lithium was not targeted in the mining process at all. The phrase "source material" should be understood to mean rock, which may be either ore grade rock that is typically (though not exclusively) the result of a mining operation, or waste rock.

[0019] It should be appreciated that the term "spodumene" refers to spodumene pyroxene, consisting of lithium aluminium inosilicate LiAI(SiO3)2-

[0020] The phrases "structurally decompose" or "structurally alter" should be understood to mean, at least, the weakening, altering and/or partially dissolving non-lithium content in source material, such that the lithium contained within the source material becomes readily accessible for leaching from the weakened, structurally altered and/or structurally dissolved non-lithium content.

[0021] The terms "dissociation," "dissociate," and "dissociating" should be understood as referring to a chemical reaction that breaks down a compound into it smaller parts.

[0022] Turning to Figure 1, as indicated above, this figure is a process diagram illustrating exemplary elements of a lithium extraction process 100, formed in accordance with aspects of the disclosed subject matter. Reference is further made with respect to Figure 2 which, as indicated, is a pictorial diagram illustrating the elements of the lithium extraction process of Figure 1, implemented in accordance with aspects of the disclosed subject matter.

[0023] As those skilled in the art will appreciate, prior to beginning the lithium extraction process defined according to aspects of the disclosed subject matter, there are some steps that one might preliminarily or initially undertake that are not part of the lithium extraction process. Generally, these preliminary/initial steps are designed to ensure economic success in extracting lithium from source material. These steps include one or more analyses with respect to the source material. For instance, the one or more analyses may include, determining the percentage/concentration of lithium in the source material, determining the amount of source material to be processes, determining whether the extraction process can be conducted in situ and, if not, determining the distance the source material must be shipped for processing, the availability of resources in situ to enable local processing (e.g., the preconcentration, the decomposition, the leaching and/or the drying operations discussed below), current prices of lithium, and the like. Of course, when an analysis (or the analyses) reveals that recovering lithium through the disclosed lithium extraction process is not commercially feasible, the process set forth in Figure 1 might not be commenced.

[0024] Assuming that there is a decision to process the source material for lithium extraction, and beginning at step 102, a concentration step is carried out on the source material. More particularly, in step 102, the source material is crushed to a predetermined size, and a preliminary mechanical separation is carried out, separating lithium-containing source material (now crushed) from non-lithium-containing source material. Regarding the elements of the concentration step, reference is further made to Figure 3.

[0025] Ideally but not mandatorily, this separation results in a concentration of 6% lithium, commonly referred to as "SC6", and which is viewed as a commercially targetable percentage. A more detailed description of the concentration step that generates this crushed rock and separates the lithium- containing crushed rock from the rest of source material is set forth below.

[0026] Figure 3 is a process diagram illustrating exemplary steps 300 of the concentration and separation step of the lithium extraction process 100, all in accordance with aspects of the disclosed subject matter. According to aspects of the disclosed subject matter, the concentration step is carried out by one or more concentration modules. Typically, though not exclusively, the one or more concentration modules are specially designed mobile concentration modules (while some of these modules may be dedicated specifically to separation steps), suitable for positioning in situ with the source material. Advantageously, locating the concentration/separation modules in situ with the source material results in lower costs arising from not transporting non-lithium containing material to a facility for processing, and is further advantageous in the "green" sense by reducing the energy expenditure required to transport non-lithium containing material. [0027] A further advantage of utilizing mobile concentration/separation modules is that this allows for ready scaling the size of the operation (concentration and separation) depending on the volume of available source material. This scaling according to the volume of available source material further reduces the environmental effects of utilizing super-sized operations.

[0028] According to embodiments of the disclosed subject matter, the concentration and separation process 300 involves ensuring (typically by crushing) that the source material is reduced to uniform size that is suitable for extracting the lithium according to the disclosed lithium extraction process and system. Thus, in accordance with aspects of the disclosed subject matter, at block 302, the source material is fed through a crushing device to reduce the source material to a predetermined, substantially uniform size. More particularly, and by way of illustration and not limitation, the concentration process includes crushing the source material to granules/grit having a diameter of roughly 50_Rm to 80_Rm. In various embodiments, granules of the source material may be reduced to a size of between l^m and lOO^m for used by the disclosed lithium extraction process.

[0029] Generally speaking, and with respect to this crushing step, the more readily accessible or exposed the lithium is within the structure of the crushed source material, the larger dimension the granules of the crushed rock (from the source material) can be accepted. Hence, a preliminary step to process 300 is to determine the target diameter (+ or - 2nm) of the crushed source material.

[0030] At block 304, and with the source material crushed to the predetermined size, the crushed material is processed by separation features of the concentration/separation modules to separate lithium-containing source material from non-lithium-containing source material (both now in a crushed state). According to aspects of the disclosed subject matter, these separation techniques include one or more of, by way of illustration and not limitation, gravimetric separation step 304a, magnetic separation 304b, and/or flotation separation 304c.

[0031] With respect to the various separation steps, and according to aspects of the disclosed subject matter, once the source material has been crushed but before the various separation processes are carried out, the crushed source material is classified based on particle/grain size. This classification is made through a screening and/or a hydrocycloic process. This screening ensures that only appropriately sized particles advance within the concentration process 100, while oversized fractions are returned for further crushing/grinding. Indeed, this classification advantageously improves the efficiency of the subsequent separation stages by maintaining a narrow size distribution among the particles that are processed.

[0032] Regarding the gravity separation step 304a, this separation technique is employed to exploit the modest density differences between spodumene and lighter gangue minerals that maybe (and frequently are) present. While spodumene itself is not extremely dense, its liberation and angular shape make it amenable to separation using spirals or shaking tables, particularly when combined with density sorting techniques such as dense media separation (DMS). DMS is especially effective when spodumene is coarsely liberated, allowing the material to be separated based on its buoyancy in a dense medium such as a ferrosilicon slurry.

[0033] Regarding the magnetic separation step 304b, in instances where gangue materials exhibit magnetic susceptibility, magnetic separation is advantageously applied as a secondary refining step (i.e., separating the gangue materials from the spodumene). Low-intensity magnetic separator units can remove magnetic impurities like iron-bearing minerals, while high-intensity magnetic separator units may aid in separating some paramagnetic contaminants. Although spodumene itself is non-magnetic, this step advantageously improves the "purity" of the source material, i.e., separating lithium-containing source material from non-lithium-containing source material, prior to any subsequent chemical or thermal processing.

[0034] Regarding the floatation separation step 304c, for fine fractions or ores with intergrowths that are not easily separable by gravity or magnetic methods alone, liquid flotation separation may be incorporated as a final separation step. According to aspects of the disclosed subject matter, liquid flotation involves floating the crushed source material in selective reagents to alter the surface chemistry of the spodumene-containing source material. This floatation creates a physical separation between source material containing spodumene/lithium and source material that does not, all based on hydrophobicity. Advantageously, this flotation process further concentrates spodumene into a high-grade lithium mineral product, for subsequent chemical extraction processes.

[0035] It should be appreciated that the result of each or any of these separation techniques is the separation of lithium-containing source material (now crushed) from non-lithium-containing source material. As illustratively shown in Figure 2, the source material 201 is supplied to one or more concentration modules 210 where the above-described crushing and separation processes take place. This results in crushed lithium-containing source material 211 and crushed non- lithium-containing source material 203. Thereafter, process 300 terminates.

[0036] In various embodiments, a mobile concentration module 210 may include a tumbler having a hardened steel drum into which source material is inserted. Also in the steel drum are hardened steel balls. As the tumbler rotates the steel drum, the steel balls crush the source material to reduce it to the desired size. In a non-exclusive embodiment, the drum may also include, or have attached, a grate that permits crushed source material to exit from the drum once the material is reduced (by crushing) to the desired particle size.

[0037] In non-exclusive, non-limited embodiments, each concentration module may also include a tub or vat in which the crushed source material enters once it is reduced to the desired particle size. This tub includes water (or a water-based solution) in which lithium-containing material floats and non-lithium-containing material sinks, creating a convenient separation between the two such that the lithium-containing source material can be readily captured for further refinement. Of course, in alternative embodiments, the concentration modules may comprise a combination of crushing units, filters, flotation mechanisms, mechanical separation units, and/or centrifuges to carry out the concentration process described above.

[0038] With reference to Figure 3, at block 306, as some of the separation techniques may include placing the crushed source material in a bath (e.g., flotation), the lithium-containing source material is partially dried using centrifugation or pressure filtration. Drying the lithium-containing source advantageously removed the water (or other liquids) used for separation purposes, reducing the weight of the lithium-containing source material that must be delivered for further processing in the disclosed lithium extraction process 100.

[0039] Returning to Figure 1, with the lithium-containing source material (now crushed) captured and at least partially dried, at block 104, the lithium-containing source material is chemically decomposed or dissociated. More particularly, this treatment step comprises decomposing the source material in which the lithium is found, which enables and facilitates leaching the lithium from that containing source material. Figure 4 describes aspects of this decomposition or dissociation treatment in greater detail.

[0040] Regarding Figure 4, this figure is a process diagram illustrating exemplary steps of a decomposition process 400, formed in accordance with aspects of the disclosed subject matter. Beginning at block 402, the lithium-containing source material 211 is placed in a heated decomposition bath. In various embodiments, the decomposition bath may be comprised of one or more inorganic compound such as sodium hydroxide or the like. In various non-exclusive embodiments, the amount of time that the lithium containing source material remains in the inorganic compound bath may be up to 24 hours, or more, at a moderate temperature (discussed below).

[0041] According to a non-exclusive embodiment of the disclosed subject matter, the inorganic compound bath is comprised of a solution of greater than 30%. In various embodiments, the inorganic compound is comprised of, or similar to sodium hydroxide, NaOH. Additionally and according to aspects of the disclosed subject matter, this "decomposition bath" is maintained at a predetermined temperature below the boiling point of water, e.g., 212 degrees Fahrenheit. This provides a huge advantage over typical calcination processes which often require heating the bath solution to at least 1400 degrees Fahrenheit, and maintaining that heat for an extended period of time. Indeed, the present, relatively low- heat, bath solution is easily maintained and consumes significantly less energy than currently used by calcination processing. [0042] Advantageously, the various embodiments of the decomposition bath, maintained at temperature for the predetermined amount of time, causing the lithium-containing source material/crushed rock to partially structurally decompose, resulting in structurally decomposed source material that exposes the contained lithium for extraction/separation. Advantageously, the various compounds used to structurally decompose the source material, when used in the low-heated bath, do not bind to or combine with the now-exposed lithium. This, advantageously, eliminates additional processing complexities in extracting lithium from compounds formed during high heat calcination, as is often common in typical processes.

[0043] At block 404, the now-structurally decomposed source material is extracted from the inorganic compound bath and, at block 406, the dissociated source material is washed in a water bath. This washing in the water bath removes any remaining compounds used in the previous step from the now- decomposed source material. At block 408, the water used to wash the decomposed lithium-containing material is extracted through one or more iterations of centrifugation. Thereafter, process 400 terminates.

[0044] With reference to Figure 2, and as a significant advantage over typical processes, the dissociation steps described above with respect to process 400 of Figure 4 may be carried out by modular and mobile decomposition modules 220. Use of one or more decomposition modules is facilitated by the fact that the energy requirements to maintain the relatively low-level heat of the decomposition bath are typically readily available in situ with the source material. This, of course, means that there is no shipping of the crushed lithium-containing source material, a huge energy savings as well as cost savings. Of course, the mobile decomposition modules 220 can then be easily scaled according to actual needs for production. Still further, the inorganic salts and/or alkaline solutions used for structurally decomposing the crushed source material are easier to manage, capture, store, recycle and/or dispose of that the highly acidic solutions in current lithium extraction processes. Indeed, the inorganic compound solutions and/or alkaline solutions can be readily filtered, recaptured and reused. [0045] As illustrated in Figure 2, one or more mobile decomposition modules 220 accept the crushed lithium-containing source material 211, process this source material as described above, and output dissociated (i.e., structurally decomposed or altered source material) lithium-containing, source material 221 and non-lithium-containing source material 213. Again, according to aspects of the disclosed subject matter, significant environmental and cost advantages are realized by reducing the current amount of source material to be further shipped and processed exclusively to the now- dissociated lithium-containing source material. Additionally, utilizing mobile decomposition modules 220 is easily scaled and can be conducted in situ, co-located with the unprocessed source material.

[0046] Returning to Figure 1, with the structurally decomposed lithium- containing source material from the process steps described above, at block 106, a leaching step of the lithium extraction process is applied to the decomposed source material. This leaching step is described in greater below with respect to Figure 5.

[0047] Turning to Figure 5, this figure is a process diagram illustrating exemplary steps of a leaching process 500, a sub-process of the lithium extraction process 100 formed in accordance with aspects of the disclosed subject matter. At block 502, the decomposed lithium-containing source material is immersed in a leaching bath. In various embodiments of the disclosed subject matter, the leaching bath comprises a moderately high concentrated alkaline solution, i.e., having a pH of between 5 and 6. The source material is left within this "leaching bath" for a second predetermined period of time, e.g., one hour at 80° Celsius, in which the lithium leaches/separates from the decomposed resource material, with the leached lithium forming a lithium slurry, LizO, within the leaching bath.

[0048] In accordance with various embodiments of the disclosed subject matter, the mildly acidic bath (between a pH of 5.0 to 6.0) is comprised of a at least a 40% solution of ammonium sulfate, (NH^SC , or other similar inorganic salts. As those skilled in the art will appreciate, in the ammonium sulfate solution, the lithium binds with elements within the lixiviant solution. This binding results in a lithium slurry, as identified above. [0049] At block 504, the material of the mildly acidic bath is then filtered, using a liquid ion exchange process for separating out the lithium slurry from the mildly acidic bath. At block 506, an evaporation and centrifuge process is applied to the lithium slurry. At block 508, a clarifier is applied to lithium slurry and the slurry is passed through another centrifuge. These steps 504-508 are all purifying operations designed to remove impurities from the lithium slurry. At block 510, the remaining lithium slurry may be washed using a water-based solution and dried, typically via centrifugation. Thereafter, routine 500 terminates.

[0050] While not specifically denoted on Figure 5, according to aspects of the disclosed subject matter, steps 504 to 508 may be carried out multiple times in an effort to purify the lithium slurry. At the end of these multiple iterations, and after washing in the water solution (step 510), the leaching sub-process 500 terminates.

[0051] Advantageously, and in contrast to the typical acid leaching processes commonly used today, which are extremely environmentally impactful, this leaching sub-process 500 uses very little energy and simply eliminates the generation of acidic byproducts which are toxic and difficult to be disposed of properly. Moreover and advantageously, the byproducts of the disclosed technology have commercialization opportunities themselves to feed other industries' supply chains.

[0052] With reference to Figure 2, one or more mobile leaching modules 230 accept the dissociated lithium-containing source material 221, process this source material as described above, and output the lithium slurry 231. The source material that is separated from the lithium slurry, i.e., the structurally decomposed source material 223 is discarded. Again, according to aspects of the disclosed subject matter, significant environmental and cost advantages are realized by processing only dissociated lithium-containing source material (whether it is shipped off or processed in situ at the source material site). Additionally, utilizing mobile leaching modules 230 is easily scaled and can be conducted in situ of the unprocessed source material.

[0053] Returning to Figure 1, at block 108 the next step in the lithium extraction process is to convert the lithium slurry (the product of the leaching process 500) into a commercially suitable/usable lithium product. The process of converting the lithium slurry to a commercially usable lithium product is described below regarding Figure 6.

[0054] Turning to Figure 6, this figure is a process diagram illustrating exemplary steps of lithium product generation process 600, formed in accordance with aspects of the disclosed subject matter. Having the lithium slurry, at block 602 a determination is made as to whether the final product is to be lithium hydroxide or lithium carbonate, or a combination of the two. According to aspects of the disclosed subject matter, the lithium slurry is comprised of wet lithium hydroxide monohydrate, LiOH.HzO. Accordingly, upon a determination that the product to be generated for commercial offering is lithium carbonate, U2CO3, the subprocess 600 advances to block 604.

[0055] At block 604, a sodium carbonate solution is mixed in with the lithium slurry and, at block 606, the lithium slurry is filtered and dried as U2CO3. Indeed, as those skilled in the art will appreciate, typically though not exclusively, lithium carbonate is often used in/with iron compounds to create lithium iron phosphate (LiFePo4), a common chemistry formulation that is used in batteries. In accordance with various embodiments of the disclosed subject matter, drying the lithium carbonate (U2CO3) may be carried out by pressure filtration or a similar technique, such that the lithium carbonate may be shipped in a crystalized form. Thereafter, the process 600 terminates. Advantageously, one of the byproducts of this process, sodium hydroxide (NaOH), can be fed back into the concentration step to be used with more upstream feedstock.

[0056] If at least some of the products to be produced is to be lithium hydroxide, LiOH x H2O, from decision block 604, the process 600 proceeds to block 608. At block 608, the lithium slurry, which is lithium hydroxide or, more accurately, lithium hydroxide monohydrate, is washed by placing the slurry in a water bath to remove any remaining impurities in the slurry.

[0057] At block 610, the washed/purified lithium hydroxide monohydrate is extracted from the water bath, leaving behind impurities and most, if not all, of the water not bound to the lithium. At block 612, the purified lithium hydroxide monohydrate slurry is dried and packaged for commercial sale/use, using similar techniques mentioned above, e.g., pressure filtration, resulting in crystalized lithium hydroxide (LiOH.HzO). Thereafter, sub-process 600 terminates.

[0058] While process 600 is illustrated as an "either-or" process with respect to the type of commercially usable lithium product to yield, in various embodiments, and without limitation to the two products identified, both paths to producing lithium hydroxide and/or lithium carbonate may be implemented.

[0059] As those skilled in the art will appreciate, there are both advantages and disadvantages to lithium hydroxide monohydrate and lithium carbonate, with the lithium hydroxide monohydrate being more energy dense but having a short shelf life, while lithium carbonate is less energy dense but significantly more stable. As will be readily appreciated, either resulting lithium product formulation has a significant commercial purpose. Moreover, with reference to Figure 1, as the product generation sub-process completes, so too does the lithium extraction process 100 of Figure 1.

[0060] With reference to Figure 2, one or more mobile production modules 240 accept the lithium slurry 231, and process the slurry as described above, thereby producing a commercially usable and/or saleable lithium product 241. Moreover, utilizing mobile production modules 240, the size of operation is easily scaled and can be conducted in situ of the unprocessed source material.

[0061] While the techniques above are described with respect to a lithium extraction process using a mild acid-based process on waste rock, it should be appreciated that the disclosed extraction process is not simply limited to lithium extraction from source material and may be advantageously applied to lithium extraction from intentionally mined rock (i.e., not waste rock or tailings.) Similarly, the techniques described in the mild acid-based process above may also be suitably applied to extracting other minerals from mined rock, waste rock and/or tailings. Indeed, in at least one alternative chemical separation process to the alkaline decomposition bath and leaching processes described above, the preconcentrated lithium bearing material is dry roasted with a strong alkaline (above 9 pH) and then water leached. This dry roasting and water leaching may operate as a substitute for the decomposition bath/inorganic salt leaching process.

Claims

1. A process for extracting lithium from source material, the process comprising: concentrating the source material to lithium-containing source material, comprising: crushing the source material to a desired dimension; and separating crushed lithium-containing source material from crushed non- lithium-containing source material; treating the crushed lithium-containing source material to expose the lithium within the mineral-containing source material for leaching, comprising: immersing the crushed lithium-containing source material into a heated decomposition bath for a first predetermined period of time, thereby partially structurally decomposing the immersed source material and exposing the lithium held within the structurally decomposed source material; and removing the structurally decomposed source material from the heated decomposition bath; and washing the structurally decomposed source material to remove remnants of the heated decomposition bath; immersing the structurally decomposed source material in a leaching bath for a second predetermined period of time to leach the lithium from the structurally decomposed source material, resulting in a lithium slurry in the leaching bath; extracting the lithium slurry from the leaching bath; and drying the lithium slurry to form a commercially usable lithium compound.

2. The process of Claim 1, wherein the desired dimension of the crushed source material comprises grains of crushed source material of between 50_Rm to 80_Rm.

3. The process of Claim 1, wherein the source material comprises unprocessed waste rock that was considered unsuitable source material for processing in a prior mining operation.

4. The process of Claim 1, wherein the heated decomposition bath is comprised of sodium hydroxide that is heated to a temperature not exceeding the boiling point of water.

5. The process of Claim 4, wherein the first predetermined period of time is 24 hours.

6. The process of Claim 1, wherein the leaching bath is comprised of a moderately high concentrated mild acid solution.

7. The process of Claim 1, wherein the lithium slurry extracted from the leaching bath comprises a lithium hydroxide slurry.

8. The process of Claim 7 , wherein drying the lithium slurry to form a commercially usable lithium compound comprises drying the lithium slurry to form the lithium compound, LiOH.HzO.

9. The process of Claim 7, wherein drying the lithium slurry to form a commercially usable lithium compound comprises combining the lithium slurry with sodium carbonate and drying the combined slurry as lithium carbonate (U2CO3).

10. The process of Claim 1, where separating crushed lithium-containing source material from crushed non-lithium-containing source material comprises: separating crushed lithium-containing source material from crushed non- lithium-containing source material according to one or more of a magnetic separation, a gravimetric separation, and/or a flotation separation.

11. The process of Claim 1, wherein the source material is comprised of between three percent (3%) and six percent (6%) lithium.

12. A lithium extraction system for extracting lithium from source material to generate a lithium compound, the system comprising: at least a first concentration module that, in operation: crushes the source material to a desired dimension; and separates crushed lithium-containing source material from crushed non- lithium-containing source material; at least one decomposition module that, in operation: immerses the crushed lithium-containing source material in a heated decomposition bath for a first period of time to partially structurally decompose the immersed source material, thereby exposing the lithium held within the structurally decomposed source material for extraction; and extracting the partially structurally decomposed material from the heated decomposition bath; at least one leaching module that, in operation: immerses the structurally decomposed source material in a leaching bath for a second predetermined period of time, resulting in the lithium in the structurally decomposed source material thereby leaching the lithium out of the source material and forming a lithium compound slurry; and extracts the lithium compound slurry from the leaching bath; and at least one production module that, in operation, dries the lithium compound slurry to form a commercially usable lithium compound.

13. The lithium extraction system of Claim 12, wherein each concentration module, including the at least first concentration module, is a mobile concentration module and co-located in situ with the source material.

14. The lithium extraction system of Claim 12, wherein the source material comprises unprocessed waste rock that was considered unsuitable source material for processing in a prior mining operation.

15. The lithium extraction system of Claim 12, wherein the source material is comprised of between three percent (3%) and six percent (6%) lithium.