Method for extracting lithium, aluminum and silicon materials from hard rock source

Abstract

An improved beta (beta)-spodumene (-LiAlSi2O6) nitric acid conversion process produces discrete lithium (Li), aluminum (Al) and silicon dioxide (SiO2) materials by (i) converting lithium nitrate LiNO3 to lithium carbonate Li2CO3; (ii) producing an Al-rich precipitate by thermal decomposition of aluminum nitrate Al (NO3) 3 or by reaction of Al (NO3) 3 with aqueous and / or solid ammonium carbonate (NH4) 2CO3; and (iii) forming a solid SiO2-rich aluminum silicate residue by selectively leaching Li and Al from the beta-spodumene. Three key reactants such as nitric acid (HNO3), ammonia (NH3) and magnesium oxide (MgO) consumed in the processing process can be regenerated internally through closed-loop chemical circulation, and the economical efficiency of the method in commercial application is greatly improved due to the characteristic of the method.

Description

Technical Field

[0001] The present invention generally relates to a method for extracting lithium, aluminum, and silicon materials from a hard rock source comprising spodumene concentrate.

[0002] Statement Regarding Federally Sponsored Research or Development

[0003] None. Background Art

[0004] Lithium (Li), aluminum (Al), and silicon (Si) materials are crucial in many commercial applications when recovered and processed from the earth's crust. In the case of lithium and its compounds, the most common uses are in the manufacture of lithium-ion batteries, lubricants, and glass ceramics, as well as the formation of lithium alloys with aluminum and magnesium (Mg). Aluminum and its compounds also have many different uses. For example, in the case of aluminum oxide, alumina (Al2O3): as a source of aluminum for the manufacture of metallic aluminum, aluminum alloys, and glass ceramics; as an abrasive; and as a catalyst support. As for silicon, its common oxide, silicon dioxide (SiO2), is used in the manufacture of, for example, glass ceramics, silica glass-based optical fibers, glass fibers, precipitated silica, and silica gel.

[0005] Particularly in the case of lithium materials, the increasing demand for higher-capacity and longer-lasting lithium batteries has driven the demand for lithium carbonate (Li2CO3) and lithium hydroxide monohydrate (LiOH·H2O). To meet this development, brine deposits in South America (mainly in Chile and Argentina) have become the main source of lithium materials, especially Li2CO3. At the same time, the extraction of lithium from lithium-containing silicate minerals has increased sharply, most notably from spodumene (in its purest form, LiAlSi2O6).

[0006] Regarding the extraction of lithium from spodumene, representative documents reflecting the prior art level include, for example, US2017 / 0175228 A1 (Hunwick) published on June 22, 2017, which describes a method including a heat treatment unit configured to operate at a temperature for converting a previously leached lithium material into solid lithium oxide (Li2O). The heat treatment unit may include a roasting furnace. The heat treatment may also indirectly heat the extracted lithium material, which may be lithium nitrate (LiNO3). In the case where the lithium material is LiNO3, the indirect heating may include catalytic combustion of ammonia (NH3) in excess air. The gas stream generated by the heat treatment can be collected and reused for acid leaching and / or for regenerating nitric acid. The reference points out that during the acid leaching process, silicate minerals can be mixed with nitric acid. In an embodiment described as a sidestream treatment scheme, the reference teaches that ammonium carbonate ((NH4)2CO3) can be used to precipitate lithium values as lithium carbonate. The reference also states that the leaching conditions may include increasing the temperature and / or pressure to accelerate the extraction of lithium values as lithium nitrate from silicate minerals, but non-lithium values in silicate minerals tend not to be leached from silicate minerals. As can be clearly seen from the following, the conditions that tend to prevent the leaching of non-lithium values are contrary to what occurs in the present invention.

[0007] Another reference, namely CA 3009374A1 (Hunwick), published on June 29, 2017, discloses a method for recovering lithium from silicate minerals, which includes: (a) mixing silicate minerals with nitric acid; (b) subjecting the mixture obtained from step (a) to a leaching treatment having conditions for leaching lithium values in the silicate minerals as LiNO3 into an aqueous phase; (c) separating LiNO3 from the aqueous phase; (d) subjecting the separated LiNO3 obtained from step (c) to heat treatment at a temperature for decomposing LiNO3 into solid lithium oxide, thereby generating a gas stream containing nitrogen oxides; and (e) feeding the gas stream containing nitrogen oxides into a nitric acid production stage, where nitric acid is formed for reuse in the leaching treatment.

[0008] In addition, CN106906359A (ICSIP Pty Limited) published on June 30, 2017, discloses a method for recovering lithium from silicate minerals, wherein, in an embodiment described as a sidestream treatment scheme, ammonium carbonate can be used to precipitate lithium as lithium carbonate.

[0009] In addition, CN113603122A (Hunan TianTai TianRun New Energy Technology Co., Ltd.), which was published on November 5, 2021, discloses a method for synthesizing battery-grade lithium carbonate, specifically including the following steps: S1: Pretreatment: After the recycled waste lithium iron phosphate batteries are discharged, disassembled, and crushed, electrode powder is obtained; S2: Nitration reaction: The above-mentioned electrode powder is added to a nitric acid solution for nitration reaction, with a liquid-solid ratio of 4:1, and a nitrate product is obtained after the reaction; S3: Roasting: The above-mentioned nitrate product is roasted to obtain a roasted product; S4: Leaching: The roasted product is leached with water, with a solid-liquid ratio of 1:2, and a lithium-rich solution is obtained by filtration; S5: Preparation of battery-grade lithium carbonate: While stirring at 50 °C, a carbonate (such as ammonium carbonate) is added to the lithium-rich solution. The reference points out that through reaction, filtration, washing, drying, screening, and packaging, battery-grade lithium carbonate is obtained.

[0010] CN115537580A (Jiangxi Flash Condensation Technology Co., Ltd.), which was published on December 30, 2022 (after the priority date of this application), discloses a method for extracting lithium from lithium ore, including the following steps: 1) After mixing lithium ore with saltpeter, ball milling, roasting, acid leaching, and filtration are carried out to obtain a lithium-containing solution and a slag rich in silicon; 2) After mixing the lithium-containing solution and a carbonate (such as ammonium carbonate), lithium is precipitated to obtain a lithium-containing compound; wherein, the lithium ore is selected from "at least two of spodumene, lepidolite, and petalite". In a preferred embodiment, the precipitation is described as being carried out at 85-100 °C.

[0011] In addition, CN1024124C (Xinjiang Nonferrous Metals Research Institute), which was published on April 6, 1994, discloses a method for preparing quilonum retard, which involves steps including using an ammonium carbonate precipitant to obtain lithium carbonate from a lithium-containing sulfate solution. Summary of the Invention

[0012] The present invention, described below in non-limiting aspects, embodiments or examples, relates to an improved method for the co-production of lithium, aluminum and silicon materials, and more particularly to a method for extracting and co-producing lithium, aluminum and silicon materials from a hard rock source in the form of a granular concentrate of one or more lithium aluminosilicate minerals, including spodumene (~LiAlSi2O6). One of the features of the present invention is the implementation of a technique involving the following steps: (i) in a reactor (such as a sealed mixing reactor), heat treatment is carried out at a temperature sufficient to decompose Al(NO3)3 in an aqueous mixture to form an Al precipitate-rich material ("Al(OH)3") containing a large amount of amorphous Al-O-H solid material mixed with other amounts of quasi-crystalline Al-O-H; or (ii) the aqueous mixture is contacted with sufficient aqueous and / or solid ammonium carbonate ((NH4)2CO3), which causes the precipitation of Al(OH)3.

[0013] In one aspect of the present invention, a method for extracting lithium, aluminum and silicon materials from a hard rock source in the form of a granular concentrate of one or more lithium aluminosilicate minerals, including spodumene, is disclosed. The method may at least include the following steps:

[0014] Providing a hard rock source in the form of a granular concentrate of one or more lithium aluminosilicate minerals, including spodumene (Step 1);

[0015] Calcining the concentrate of Step 1 at a high temperature sufficient to convert substantially all of the spodumene therein from its natural alpha (α) polymorphic crystal structure to a synthetic beta (β) crystal structure (Step 2);

[0016] Providing an aqueous solution of nitric acid (HNO3) (Step 3);

[0017] Mixing the minerals in Step 2 with the aqueous solution of nitric acid (HNO3) and subjecting the resulting mixture to conditions in a first main sealed mixing reactor sufficient to achieve the leaching of lithium (Li) and aluminum (Al) from the β-spodumene in the concentrate of Step 1, and possibly the leaching of one or more other minerals in the concentrate, and optionally, further leaching the calcined concentrate with nitric acid in one or more secondary sealed mixing reactors (Optional Step 5);

[0018] Transferring the slurry from the first main sealed mixing reactor or from one or more optional secondary sealed mixing reactors to a second main sealed mixing reactor having a lower gas pressure to reduce the pressure of the transferred slurry, which causes the generation of N-O-H gas from the transferred slurry (Step 6);

[0019] Removing the slurry from the second main sealed mixing reactor and allowing the slurry to cool (Step 7);

[0020] The cooled slurry is separated into two parts, one part being rich in leached granular β-spodumene and the other part being a liquid containing a relatively small amount of entrained or suspended solid material. The leached granular β-spodumene-rich part is transferred to a mixer where it is washed with high-purity water and then optionally contacted separately with an aqueous solution of Na and / or K hydroxide under conditions sufficient to dissolve Li, Al, and SiO2. Finally, further treatment is carried out to recover: (i) Li as one or more of Li2CO3, LiOH (aqueous (aq)), LiOH·xH2O (where x = 1, 2, 3, or 6), and / or Li2O·ySiO2 (where y = 1 or 2); (ii) Al as one or more of Al(OH)3, Al2O3·H2O, and Al2O3; and (iii) SiO2, which is retained in (Na,K)2SiO3(aq) and / or as precipitated silica and / or silica gel (step 8); and

[0021] In a third main seal mixing reactor, the wash water containing LiNO3(aq) and Al(NO3)3(aq) from the mixer is mixed with the liquid part containing a relatively small amount of entrained or suspended solid material, and then the resulting liquid mixture is subjected to either of the following treatments: (i) heat treatment at a temperature sufficient to convert Al(NO2)3 in the mixture to Al(OH)3; or (ii) contact with sufficient aqueous and / or solid (NH4)2CO3, which causes precipitation of Al(OH)3 (step 9).

[0022] Other more specific exemplary embodiments will be described in more detail below. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Preferred embodiments of the present invention will be described below in conjunction with the accompanying drawings, which are used to illustrate but not limit the present invention, where any same names represent the same elements, and where:

[0024] Figure 1 A process flow diagram (block diagram) of the "initial production part" of an exemplary method of the present invention is shown;

[0025] Figure 2 A process flow diagram of the "final production part" of an exemplary method of the present invention is shown ( Figure 1 continuation); and

[0026] Figure 3 A process flow diagram of the "supply / generation / regeneration part" of an exemplary method of the present invention is shown ( Figure 1 and Figure 2 continuation).

[0027] In several flowcharts of the drawings, the same reference numerals represent the same parts. Detailed implementation manners

[0028] The following detailed description is merely exemplary in nature and is not intended to limit the described embodiments or the application and uses of the described embodiments. As used herein, the term "exemplary" or "illustrative" means "serving as an example, instance, or illustration". Any embodiment described herein as "exemplary" or "explanatory" cannot necessarily be construed as superior to other embodiments. All of the embodiments described below are exemplary embodiments, intended to enable those skilled in the art to utilize the embodiments of the present disclosure and are not intended to limit the scope of the present disclosure, which is defined by the claims.

[0029] Some features of the drawings may be described using designated numbers or relative ranking terms, such as "first", "second", etc. Such designated numbers or relative ranking terms are only used for reference to the drawings and do not mean to limit the disclosed embodiments in terms of order, nor do they mean to exclude additional unrecited steps or method components at any point in the described method, unless expressly defined in the appended claims.

[0030] Furthermore, the present invention is not intended to be bound by any explicit or implicit theory presented in the foregoing technical field, background, brief summary, or the following detailed description. It should also be understood that the specific devices and methods shown in the drawings and described in the following specification are merely simple exemplary embodiments of the inventive concept defined in the appended claims. Therefore, the specific quantities, dimensions, and / or other physical characteristics associated with the embodiments disclosed herein should not be considered restrictive, but merely exemplary, unless expressly stated otherwise in the claims.

[0031] Furthermore, those skilled in the art will understand by reading the present disclosure that "a" and "an" generally each mean "at least one", but do not exclude a plurality, unless the context otherwise provides. In addition, the term "or" in a list of enumerated items means "at least one of the items" and thus does not exclude a plurality of items in the list.

[0032] As described above, the basic concept of the present invention relates to the extraction of lithium, aluminum, and silica from a hard rock source, which is in the form of a particulate concentrate of one or more lithium aluminosilicate minerals, called "spodumene concentrate". Spodumene is a mineral with an end-member (ideal, pure, theoretical, etc.) composition of LiAlSi2O6. Spodumene concentrate is a particulate mechanical mixture of minerals produced by crushing and grinding rocks mined from spodumene pegmatite deposits, and the proportion of spodumene in the resulting particulate solid is increased by at least one concentration method, such as density medium separation and froth flotation.

[0033] (Step 1): Generally, the first step of this processing method starts from granular spodumene concentrate. The supply of commercially sold spodumene concentrate is usually graded according to its Li2O content. Pure spodumene contains 8.03 wt.% of Li2O; the original spodumene pegmatite ore usually contains 1 wt.% - 2 wt.% of Li2O; spodumene concentrate usually contains 6 wt.% - 7 wt.% of Li2O, where the proportion of spodumene is usually between 75 wt.% and 87 wt.%, which is the requirement for the preparation of Li2CO3 and / or LiOH·H2O. Spodumene concentrate contains at least 7.6 wt.% of Li2O and has a low iron content, and is used for manufacturing ceramics and other special applications.

[0034] (Step 2): In an exemplary embodiment, the second step of the method involves calcining the granular spodumene concentrate provided in Step 1 at a temperature of about 900 °C to about 1200 °C or within a temperature range to convert the crystal structure of spodumene from its most common natural form, alpha (α) polymorph, to a synthetic beta (β) configuration.

[0035] (Step 3): Generally, the third step of the method involves using an aqueous nitric acid solution (HNO3(aq)). The solution preferably contains about 20 wt.% to about 68 wt.% of HNO3(aq), and the balance is mainly high-purity water. Most preferably, for commercial applications, the nitric acid will contain about 40 wt.% to about 68 wt.% of HNO3(aq).

[0036] (Step 4): Generally, the fourth step involves taking out the β-spodumene concentrate produced in Step 2 and mixing it into the nitric acid provided in Step 3, possibly under the conditions of about 25 ≤ T (°C) ≤ about 80 and about 1 ≤ P (atm) ≤ about 10; plus optionally combining it with compressed NO2 - O2 ± H2O ± HNO3 (N - O - H) gas, before, during, and / or after the material is transferred to the first main sealed mixing reactor. In this step, the extraction of granular β-spodumene begins, and some lithium and a part of aluminum in the mineral dissolve in the acidic aqueous liquid. It is considered that the transfer of Li and Al from β-spodumene particles to the enclosed acidic aqueous liquid occurs through one or more chemical reactions similar to the following Reaction 1, and the calculated values of each of the above materials represent the mass (in metric tons) expected to be consumed or produced during the reaction process.

[0037] Reaction 1:

[0038]

[0039] Then, during and after charging the reactor, the acidic slurry ±N-O-H gas can be heated to about 120 °C at about 1 < P(atm) ≤ about 10. Heating to about 120 °C can be achieved by passing the slurry through a pipe immersed in a heat transfer liquid for temperature regulation at about 120 < T(°C) ≤ about 140. In addition, the flow path of the acidic slurry ±N-O-H gas may include a mixer having a spike-shaped rotor that rotates rapidly within the housing of such a structure, such that all of the acidic slurry ±N-O-H gas is forced to flow around the spikes as it moves from the front end of the mixer to the exit point. Preferably, when the material passes through the mixer, the pressure and temperature of all the material will be maintained or allowed to slightly increase. The guiding principle for achieving satisfactory nitric acid Li-Al extraction of β-spodumene is that the mixing is preferably done under physicochemical conditions that tend to maintain or even increase the weight percentage concentration of HNO3(aq) in the nitric acid, while preventing any significant loss of β-spodumene. For example, to mitigate the decrease in the weight percentage of HNO3(aq) that occurs during the extraction of Li and Al from β-spodumene, the starting weight percentage concentration of HNO3(aq) in the nitric acid can be in the range between 50 wt% - 68 wt%, and the starting weight ratio of HNO3(aq) to β-spodumene can be set high enough to ensure that the concentration of HNO3(aq) remains high throughout the Li-Al extraction process. Additionally, alternatively, the weight percentage concentration of HNO3(aq) in the nitric acid can be kept high by N-O-H gas (if present), which will achieve Model Reaction 2 below.

[0040] Reaction 2:

[0041]

[0042] The end result of Reaction 2 is that the consumption of HNO3(aq) in the nitric acid by Reaction 1 is offset by the replenishment of HNO3 in the acidic mixture due to Reaction 2. Finally, at the end of this step, the produced slurry preferably contains about 30 vol.% - 70 vol.% (vol.%) solids.

[0043] (Optional Step 5): The fifth step of the method is optional and involves the slurry formed in Step 4. This slurry can be transferred to one or more secondary sealed mixing reactors where Li and Al are further extracted from the β-spodumene through one or several reactions similar to Reaction 1. Laboratory-scale tests conducted so far have shown that Steps 3 and 4 ± Step 5 will ultimately remove nearly 90% of the Li and 15% to 30% of the Al from the calcined granular β-spodumene.

[0044] (Step 6): The sixth step of the method involves the slurry generated in Steps 3 and 4 ± 5 flowing out of the reactor, being pumped or driven by a pressure gradient, through a device capable of reducing the gas pressure to a level almost equal to the pressure in the second main-sealed mixing reactor that receives the slurry. The gas pressure in the second main-sealed mixing reactor can be kept low (e.g., close to 1 atm) by creating a headspace into which N-O-H gas can enter from the acid slurry heated from below, and the N-O-H gas can be extracted from the headspace through the sides and / or top of the headspace to facilitate the gradual degassing of the slurry. The gases considered to be removed will include chemical materials rich in HNO3, H2O, NO2, and O2 in total amounts. Further considered is that in the commercial application of the processing steps disclosed herein, the removed gases containing the N-O-H volatile materials can subsequently be added to the N-O-H gas formed in Step 37, and then the large amount of mixed gases will be reacted (Step 38) to regenerate most of the nitric acid consumed in Step 4 or both Steps 4 and 5.

[0045] (Step 7): The seventh step involves removing the slurry formed in Step 6 from the second main-sealed mixing reactor and cooling it to about 25 ≤ T (°C) ≤ about 60, and then dividing it into two parts, one part rich in leached granular β-spodumene and the other part rich in a liquid containing very little entrained or suspended solid material. Subsequently, the liquid is transferred to a third main-sealed mixing reactor. The material separation can be achieved by centrifugation and / or filtration. As shown in Reaction 1 above, the liquid generated in this step will contain a large amount of LiNO3(aq) and Al(NO3)3(aq).

[0046] (Step 8): The eighth step of the method involves feeding most of the leached granular β-spodumene (accompanied by one or more of a small amount of quartz, feldspar, mica, etc.) separated in Step 7 into a mixer, washing it with high-purity water in the mixer, and then feeding the resulting washing water containing LiNO3(aq) and Al(NO3)3(aq) into the third main-sealed mixing reactor (Step 9). Preferably, the solid is washed with the least amount of high-purity water, and optionally, most of the leached β-spodumene can be processed as described in Steps 28 and 29 to produce additional Li-containing and Al-containing materials, as well as a large amount of one or more SiO2-containing materials.

[0047] (Two important points to note: (i) Steps 9 - 13 below describe the technique of the present invention for producing an Al-rich precipitate (“Al(OH)3”) from the LiNO3 - Al(NO3)3 - H2O - … liquid; and (ii) herein and in the rest of the disclosure, “-…” is used to indicate that other materials may be present in the aqueous solution.)

[0048] Step 9 - Ammonium Carbonate Treatment Option: In one embodiment, the ninth step involves providing a liquid comprising a substantial amount of (NH4)2CO3(aq) and / or a substantial amount of high-purity (NH4)2CO3(solid(s)) dissolved in high-purity water and mixing it with the liquid remaining in the third main-sealed mixing reactor, resulting in the precipitation of Al(OH)3(s). Four model reactions related to the precipitation of Al(OH)3(s) from the LiNO3 - Al(NO3)3 - H2O -... liquid using (NH4)2CO3(aq,s) are given below.

[0049] Reaction 3a:

[0050] Al(NO3)3(aq) + HNO3(aq) + 2(NH4)2CO3(aq,s) + H2O(liq) → Al(OH)3(s)↓ + 4NH4NO3(aq) + 2CO2(g)↑

[0051] Reaction 3b:

[0052] 2Al(NO3)3(aq) + (NH4)2CO3(aq,s) + 7H2O(liq) → 2Al(OH)3(s)↓ + 4NH4NO3(aq) + CO2(g)↑ + 4O2(g)

[0053] Reaction 3c:

[0054] 2Al(NO3)3(aq) + 2(NH4)2CO3(aq,s) + 5H2O(liq) → 2Al(NO3)(aq) + 2(NH4)2CO3(aq.s) + 5H2O(liq) → 2Al(OH)3(s)↓ + 5NH4NO3(aq) + 2CO2(g)↑ + 4O2(g)↑

[0055] Reaction 3d:

[0056]

[0057] Preferably, precipitation is induced at about 25 ≤ T(°C) ≤ about 60 and P = about 1 atm. To ensure optimal production of Al(OH)3(s): First, the amount of (NH4)2CO3(aqueous, solid(aq,s)) provided should be close to the minimum amount required to remove all Al(NO3)3(aq) from the liquid; Second, the CO2(gas(g)) produced should be removed from the reactor as it forms.

[0058] Optional Step 9 - Heat Treatment Option: As an alternative to the ammonium carbonate treatment described earlier, it is possible (and sometimes preferred) to heat-treat the mixture in the third main-sealed mixing reactor at a temperature sufficient to decompose Al(NO3)3 in the mixture to form Al(OH)3(s). The temperature for carrying out the heat treatment option can be in the range of about 80 to about 200 °C. In this option, Reactions 3a - 3d are avoided, and high-purity (NH4)2CO3(aq, s) does not come into contact with LiNO3(aq) until the precipitation of Al(OH)3(s) is complete and until the time when it becomes over-reacted to precipitate Li2CO3(s) in Reaction 4a and / or Reaction 4b.

[0059] (Step 10): The tenth step of the method involves removing the aqueous slurry containing Al(OH)3(s) and LiNO3(aq) formed in Step 9 from the third main-sealed mixing reactor and separating it into an Al(OH)3(s)-rich portion and a liquid-rich portion. The material separation can be achieved by centrifugation and / or filtration.

[0060] (Step 11): The eleventh step of the method involves feeding the precipitate separated in Step 10 into a mixer, where it is mixed with high-purity water and vigorously stirred / agitated to produce a slurry, which is then separated into an Al(OH)3(s)-rich portion and a liquid-rich portion. Preferably, the slurry in the mixer will contain about 40 vol% - 70 vol% solids. The separation of Al(OH)3(s) and the liquid after mixing can be achieved by centrifugation and / or filtration.

[0061] (Step 12): The twelfth step involves heating the wet Al(OH)3(s)-rich solid material produced in Step 11 to a temperature above about 100 °C or in a temperature range to dehydrate the material, which may result in the production of one or more forms of crystalline Al(OH)3(s) and / or Al2O3(s).

[0062] (Step 13): In the thirteenth step, the liquids formed in Steps 10 and 11 are mixed and fed into a fourth main-sealed mixing reactor. The treatment options before entering this reactor include (i) flowing through an evaporator, where the concentration of the dissolved solids increases due to the removal of water, and (ii) using compressed NH3-CO2 gas to pressurize the liquid to 1 < P(atm) ≤ about 10.

[0063] (Important Note: The following Steps 14 - 16 and Step 22 describe four different methods for converting LiNO3(aq) to high-purity Li2CO3(s). By using one of these methods, or by two or more methods, sufficient conversion can be achieved, for example as follows: (i) Steps 14 and 15, optionally followed by Step 22; and (ii) Step 16, followed by Step 22.

[0064] (Step 14): The fourteenth step involves combining the liquid in the fourth main-sealed mixing reactor with a liquid that contains a rich amount of (NH4)2CO3(aq) and / or high-purity (NH4)2CO3(s) dissolved in high-purity water, and the amount of the supplied (NH4)2CO3(aq,s) is slightly in excess of the amount required for the reaction to remove most of the LiNO3(aq). The precipitation of Li2CO3(s) may occur mainly through the following Model Reaction 4a.

[0065] Reaction 4a:

[0066]

[0067] Reaction 4a is preferably carried out at about 25 ≤ T (°C) ≤ about 80 and about 1 ≤ P (atm) ≤ about 10.

[0068] (Step 15): The fifteenth step can be an additional or alternative step. The liquid in the fourth main-sealed mixing reactor is combined with a mixed NH3-CO2 gas that has a composition previously shown to be suitable for reacting with LiNO3(aq) to produce Li2CO3(s), so the amount of the supplied NH3-CO2 gas is sufficient to first react away most of the LiNO3(aq) and secondly to form and leave a certain amount of (NH4)2CO3(aq). The precipitation of Li2CO3(s) may occur mainly through the following Model Reaction 4b.

[0069] Reaction 4b:

[0070] 2LiNO3(aq) + 2NH3(g) + CO2(g) + H2O(liq) → Li2CO3(s)↓ + 2NH4NO3(aq)

[0071] Reaction 4b is preferably carried out at about 25 ≤ T (°C) ≤ about 80 and about 1 ≤ P (atm) ≤ about 10.

[0072] (Step 16): Optionally, the sixteenth step involves combining the liquid in the fourth main-sealed mixing reactor with any one or more materials that result in (i) the co-production of Li2CO3(s) and NH4NO3(aq), and (ii) the formation and retention of (NH4)2CO3(aq) at about 25 ≤ T (°C) ≤ about 80 and about 1 ≤ P (atm) ≤ about 10.

[0073] (Step 17): The seventeenth step involves the Li2CO3(s)-LiNO3(aq)-NH4NO3(aq)-(NH4)2CO3(aq)-H2O(liquid(liq))-… slurry produced by one or more of steps 14, 15, and 16, which is transferred to a fifth main sealed mixing reactor where almost all of the (NH4)2CO3(aq) present is decomposed. The decomposition of (NH4)2CO3(aq) may occur mainly according to the following model decomposition reaction.

[0074] Decomposition reaction:

[0075] (NH4)2CO3(aq) → 2NH3(g)↑ + CO2(g)↑ + H2O(liq)

[0076] This decomposition reaction is preferably carried out under the conditions of about 60 ≤ T(°C) ≤ about 120 and P = about 1 atm to ensure the maximum decomposition of (NH4)2CO3(aq). The generated NH3-CO2 gas should be removed from the reactor as it is formed.

[0077] (Optional Step 18): Optionally, the eighteenth step involves the NH3-CO2 gas extracted from the fifth main sealed mixing reactor (step 17) being compressed and temporarily stored in a pressure vessel.

[0078] (Step 19): The nineteenth step involves removing the Li2CO3(s)-LiNO3(aq)-NH4NO3(aq)-H2O(liq)-… slurry produced in step 17 from the fifth main sealed mixing reactor and separating it into a Li2CO3(s)-rich portion and a liquid-rich portion. The material separation can be achieved by centrifugation and / or filtration.

[0079] (Step 20): The twentieth step involves feeding the wet Li2CO3(s) separated in step 19 into a mixer where it is mixed with high-purity water and then vigorously stirred / agitated to produce a Li2CO3(s)-LiNO3(aq)-NH4NO3(aq)-H2O(liq)-… slurry, which is then separated into a Li2CO3(s)-rich portion and a liquid-rich portion. The material separation can be achieved by centrifugation and / or filtration.

[0080] (Step 21): The twenty-first step involves mixing the LiNO3-NH4NO3-H2O-… liquids separated in steps 19 and 20 and feeding them into a sixth main sealed mixing reactor, and the processing options before entering this reactor are an inflow and an outflow evaporator, where the concentration of the dissolved solids increases due to the removal of water.

[0081] (IMPORTANT NOTE: The purpose of Step 22 below is to react away almost all of the LiNO3(aq) present in the sixth main-sealed mixing reactor, assuming that there is sufficient of this material in the liquid (Step 21) to demonstrate that almost complete conversion of LiNO3(aq) to Li2CO3(s) can be achieved using (Na,K)2CO3(aq). For the sake of the completeness of this document, it is stipulated that the latter case - that there is sufficient of this material in the liquid (Step 21) - holds.

[0082] (Step 22): The twenty-second step involves combining the LiNO3-NH4NO3-H2O-… liquid (i) in the sixth main-sealed mixing reactor with a liquid in which the solid material dissolved in high-purity water is (Na,K)2CO3(aq), and / or (ii) with high-purity (Na,K)2CO3(s). The precipitation of Li2CO3(s) may occur mainly through the following model reactions.

[0083] Supplementary Li2CO3 precipitation reaction:

[0084] 2LiNO3(aq)+(Na,K)2CO3(s,aq)→Li2CO3(s)↓+2(Na,K)NO3(aq)

[0085] This precipitation reaction is preferably induced at about 25 ≤ T (°C) ≤ about 120 and P = about 1 atm.

[0086] (Step 23): The twenty-third step involves removing the Li2CO3(s)-NH4NO3(aq)-(Na,K)NO3(aq)-H2O(liq)-… slurry produced in Step 22 from the sixth main-sealed mixing reactor and separating it into a Li2CO3(s)-rich part and a liquid-rich part. The separation of the materials can be achieved by centrifugation and / or filtration.

[0087] (Step 24): The twenty-fourth step involves feeding the Li2CO3(s) produced in Step 23 into a mixer, where it is mixed with high-purity water and then vigorously stirred to produce a Li2CO3(s)-NH4NO3(aq)-(Na,K)NO3(aq)-H2O(liq)-… slurry, which is then separated into a Li2CO3(s)-rich and a liquid-rich part. Preferably, the slurry in the mixer comprises about 40 vol% - 70 vol% solids. The separation of the mixed materials can be achieved by centrifugation and / or filtration.

[0088] (Step 25): The twenty-fifth step involves mixing the wet Li2CO3(s) produced in Steps 20 and 24, which can then optionally be further processed to remove impurities, and then heating to a temperature or temperature range between about 80 °C and about 120 °C to thoroughly dry the material.

[0089] (Step 26): The twenty-sixth step involves mixing the NH4NO3-(Na,K)NO3-H2O-… liquid separated in steps 23 and 24 and feeding it into the seventh main-sealed mixing reactor. The processing options before entering this reactor are inflow and outflow evaporators. In the evaporator, due to the removal of water, the concentration of the dissolved solids increases.

[0090] (Important note, optional step 27 indicates that the method described herein is fully applicable to reacting β-spodumene concentrate to produce LiOH·H2O(s).

[0091] (Optional step 27): Optionally, the twenty-seventh step involves converting the wet high-purity Li2CO3(s) produced in steps 20 and 24 into high-purity LiOH·H2O(s). The formation of LiOH·H2O(s) from Li2CO3(s) can be achieved in various ways, and one particularly well-known way is through the metathesis reaction (Reaction 5) below.

[0092] Reaction 5:

[0093]

[0094] The hydration state of LiOH·xH2O(s) is usually adjusted after Reaction 5 to produce LiOH·H2O(s).

[0095] (Important note: Steps 28 and 29 describe the production and recovery of materials containing Li, Al, SiO2, and Fe from the basically leached granular β-spodumene produced in step 8. 3+ materials.

[0096] (Step 28): The twenty-eighth step involves reacting the basically leached granular β-spodumene produced in step 8 with an aqueous solution of Na-K hydroxide at about 25 ≤ T (°C) ≤ about 120 and about 1 ≤ P (atm) ≤ about 10 to dissolve the Li and Al contained therein, as well as the hitherto poorly soluble SiO2. The dissolution of the leached granular β-spodumene in (Na,K)OH(aq) may occur through one or more chemical reactions similar to Reaction 6 below.

[0097] Reaction 6:

[0098]

[0099] In this regard, it is worth noting that recent laboratory-scale test results indicate that trace amounts of iron in the nitric acid-leached granular β-spodumene do not dissolve through reaction with (Na,K)OH(aq), but are oxidized to form highly water-insoluble (but possibly substantially hydrated) ferric iron (Fe3+ ) Oxide / hydroxide solid materials. Thus, centrifugation and / or filtration can be used to separate the Fe 3+ oxide / hydroxide solid materials from the co-produced liquid (Reaction 6) before further processing, where the further processing focuses on separating and recovering the Li-, Al-, and SiO2-containing materials dissolved by Reaction 6.

[0100] (Step 29): The twenty-ninth step involves recovering the Li, Al, and SiO2 dissolved in Step 28 by: (i) separating Li as Li2CO3(s) and / or LiOH(aq) and / or Li2O·xH2O(s) (x = 1, 2, 3, 6) and / or Li2O·xSiO2 (x = 1, 2); (ii) separating Al as Al(OH)3(s) and / or Al2O3·H2O and / or Al2O3(s); and (iii) retaining SiO2 in (Na,K)NO3(aq) and / or separating it as precipitated silica and / or silica gel.

[0101] (Important note: Steps 30 - 38 describe the processing steps for supplying, generating, or regenerating various materials consumed in the process of the present invention.)

[0102] Generating NH3(g) and co-producing a high-purity Mg(NO3)2-H2O liquid.

[0103] (Step 30): The thirtieth step involves contacting the NH4NO3-(Na,K)NO3-H2O-… liquid in the seventh main sealed mixing reactor with (i) an excess of magnesium oxide MgO(s) or (ii) an excess of MgO(s)+magnesium hydroxide Mg(OH)2 or (iii) an excess of Mg(OH)2(s) to prepare an aqueous solution of magnesium nitrate Mg(NO3)2(aq), H2O(liq), and NH3(g). It is considered that if the NH4NO3(aq) in the seventh main sealed mixing reactor reacts with MgO(s) or MgO(s)+Mg(OH)2(s), Mg(NO3)2(aq) and NH3(g) are produced through all three reactions 7a, 7b, and 7c, or conversely, if the NH4NO3(aq) only reacts with Mg(OH)2(s), Mg(NO3)2(aq) and NH3(g) are produced only through Reaction 7c.

[0104] Reaction 7a:

[0105]

[0106] Reaction 7b:

[0107] MgO(s)+H2O(liq)→Mg(OH)2(s)

[0108] Reaction 7c:

[0109] 2NH4NO3(aq) + Mg(OH)2(s) → Mg(NO3)2(aq) + 2H2O(liq) + 2NH3(g)↑

[0110] Regeneration of (NH4)2CO3(aq) and / or (NH4)2CO3(s).

[0111] (Step 31): The thirty - first step involves mixing (i) the CO2(g) generated in step 9, (ii) the NH3 - CO2 gas generated in step 17, (iii) the NH3(g) formed in step 30, and (iv) the provided CO2(g) in a gas mixer.

[0112] (Step 32): The thirty - second step involves feeding the mixed gas generated in step 31 into an eighth main sealed mixing reactor to produce a liquid in which the solid material dissolved in high - purity water is almost entirely (NH4)2CO3(aq). The synthesis of (NH4)2CO3(aq) can be achieved by initiating Reaction 8a, Reaction 8b, and / or Reaction 8c, as described below. In any case, the final result is (NH4)2CO3(aq) dissolved in high - purity H2O(liq).

[0113] Reaction 8a:

[0114] NH3(g) + H2O(liq) → NH4OH(aq)

[0115] Reaction 8b:

[0116] 2NH4OH(aq) + CO2(aq,g) → (NH4)2CO3(aq) + H2O(aq)

[0117] Reaction 8c:

[0118]

[0119] (Optional Step 33): Optionally, the thirty - third step involves removing water from the (NH4)2CO3 - H2O liquid (step 32) to precipitate, and subsequently separating high - purity (NH4)2CO3(s).

[0120] (Step 34): The thirty - fourth step involves feeding the high - purity (NH4)2CO3(aq) produced in step 32 and / or the high - purity (NH4)2CO3(s) crystallized in step 33 back to one or both of step 9 and step 14 to minimize the net consumption of (NH4)2CO3(aq,s).

[0121] Regeneration / production of the mixed NH3-CO2 gas applicable to Step 15.

[0122] (Optional Step 35): Optionally, the thirty-fifth step involves the mixing of (i) the CO2(g) produced in Step 9, (ii) the NH3-CO2 gas produced in Step 17, (iii) the NH3(g) formed in Step 30, and (iv) the supplied CO2(g), all of which are conveyed through a gas mixer to produce the mixed NH3-CO2 gas applicable to Step 15.

[0123] Regeneration of HNO3(aq,g).

[0124] (Step 36): The thirty-sixth step involves removing the slurry produced in Step 30 from the seventh main-sealed mixing reactor and sending it to an evaporator, where most of the water in the liquid and a small amount of HNO3(aq) formed therein are separated. In this step, vacuum suction can be used to reduce the time required for water removal.

[0125] (Step 37): The thirty-seventh step involves devolatilizing the partially dehydrated slurry produced in Step 36, preferably at P = about 1 atm and at a temperature or temperature range above the upper limit of the thermal stability of Mg(OH)2(s) and Mg(NO3)2(liq) but below the upper limit of the thermal stability of (Na,K)NO3(liq). Heating of Mg(OH)2(s)+Mg(NO3)2(liq) to a temperature above about 330 °C can be considered, at which point decomposition is expected to proceed via the following model reactions.

[0126] Reaction 9a:

[0127] Mg(OH)2(s) → MgO(s)+H2O(g)

[0128] Reaction 9b:

[0129]

[0130] (Step 38): The thirty-eighth step involves feeding the N-O-H gas produced in Steps 6, 36, and 37 together with sufficient H2O(liq) into the tenth main-sealed mixing reactor, where a large amount of HNO3 can be produced via Reaction 2.

[0131] Steps 39 - 41 describe the method for recovering (Na,K)NO3(aq) and / or (Na,K)NO3(s).

[0132] (Step 39): The thirty-ninth step of the method involves mixing the MgO(s)+(Na,K)NO3(s) produced in step 37 into an unsaturated solution of (Na,K)NO3(aq) dissolved in high-purity water, with the aim of dissolving (Na,K)NO3(s) while minimizing the conversion of MgO(s) to Mg(OH)2(s). At the end of this step, the slurry is separated into a MgO(s)-rich part and a liquid-rich part. The material separation can be achieved by centrifugation and / or filtration.

[0133] (Step 40): The fortieth step involves dividing the liquid produced in step 39 into two parts, designated herein as part 1 and part 2, and then adding an amount of high-purity water approximately equal to that of part 2 to part 1.

[0134] (Optional step 41): Optionally, the forty-first step involves removing water from liquid part 2 (step 40) to precipitate (Na,K)NO3(s).

[0135] (Important note: Steps 1-29 produce a single mass of Li-, Al-, and SiO2-containing material from a single mass of granular concentrate of one or more lithium-containing aluminosilicate minerals (including spodumene) (“spodumene concentrate”), while steps 30-38 show that most of the materials consumed in the processing can be directly recycled. In step 42 below, steps 1-29 and steps 30-41 are combined to enable the repeated batch or substantially continuous production of Li-, Al-, SiO2-, and (Na,K)NO3-containing material from a stable supply of spodumene concentrate, and to enhance the processing by creating an internal chemical cycle in which the consumption and regeneration of key reactants may approach equilibrium. It should also be noted that the production of NH3(g) (step 30) and the regeneration of HNO3(aq,g) (steps 36-38) automatically involve an approximate mass balance of internal consumption and regeneration of MgO(s) and / or Mg(OH)2(s).

[0136] (Optional step 42): Optionally, the forty-second step can be used to produce large quantities of Li-, Al-, SiO2-, and (Na,K)NO3-containing material from a stable supply of provided spodumene concentrate, as follows:

[0137] (i) The provided spodumene concentrate is (a) calcined according to step 2, (b) cooled to below about 100 °C, and then (c) mixed and reacted with nitric acid as described in steps 4 and 5. The initial mass of nitric acid required for steps 4 and 5 is obtained entirely from one or more external sources (step 3); subsequent amounts will come mainly from steps 6 and 36-38.

[0138] (ii) Precipitate Al(OH)3(s) as described in step 9, wash as described in step 11, and finally dehydrate as described in step 12. If using aqueous and / or solid (NH4)2CO3 to precipitate Al(OH)3(s), ensure that the initial mass of (NH4)2CO3 required for optimal production of Al(OH)3(s) is obtained entirely from one or more external sources; subsequent amounts are mainly from (a) steps 31 and 32 and / or (b) steps 31 - 33.

[0139] (iii) Li2CO3(s) is precipitated by one or more of the methods determined in steps 14 - 16 and may also be precipitated by the techniques described in step 22. In step 14, the initial mass of (NH4)2CO3(aq,s) is obtained entirely from one or more external sources; subsequent amounts will be mainly from (a) steps 31 and 32 and / or (b) steps 31 - 33. In step 15, the initial mass of NH3 - CO2 gas + H2O(liq) is obtained entirely from one or more external sources; subsequent amounts will be mainly from step 31.

[0140] (iv) As described in step 27, Li2CO3(s) formed in one or more of steps 14 - 16 and possibly subsequent step 22 is optionally converted to LiOH·H2O(s).

[0141] (v) Optionally, steps 39 - 41 are used to recover a certain amount of (Na,K)NO3(aq) and / or (Na,K)NO3(s).

[0142] (vi) Feed the wet MgO(s) ± Mg(OH)2(s) produced in step 39 into step 30 to essentially replace the MgO(s) ± Mg(OH)2(s) consumed in this step.

[0143] (vii) Mix liquid portion 1 (step 40) into the newly produced highly dehydrated MgO(s) + (Na,K)NO3(s) produced in step 37.

[0144] Table 1 below shows the calculated tonnes (tonne) of each material consumed (C) and produced (P) in Reactions 1, 2, 3d, 4a, 5, 6, 7a, 8c, and 9b.

[0145] Table 1

[0146]

[0147] Table 2 below shows the calculated total amounts (tonnes) of each reactant and reaction product in the mass balance for Reactions 1, 2, 3d, 4a, 5, 6, 7a, 8c, and 9b.

[0148] Table 2

[0149]

[0150] Since many modifications, variations and changes in detail can be made to the preferred embodiments of the present invention, all matters shown in the above description and drawings should be construed as illustrative and not restrictive. In addition, it should be understood that any feature presented in an embodiment can be integrated into any other embodiment unless otherwise expressly stated. The scope of coverage of the present invention shall be determined by the appended claims and their legal equivalents.

Claims

1. A method for extracting lithium, aluminum, and silicon materials from lithium aluminosilicate minerals, wherein the lithium aluminosilicate minerals include spodumene - LiAlSi2O6, and the method at least includes the following steps: Providing a hard rock source in the form of a granular concentrate of one or more lithium aluminosilicate minerals (step 1), wherein the lithium aluminosilicate minerals include spodumene; Calcining the concentrate at a high temperature sufficient to substantially convert all of the spodumene therein from its natural alpha (α) polymorphic crystal structure to a synthetic beta (β) crystal structure (step 2); Providing an aqueous solution of nitric acid (HNO3) (step 3); Mixing the calcined concentrate with the aqueous nitric acid solution, and then subjecting the resulting mixture to conditions sufficient to leach lithium (Li) and aluminum (Al) from the calcined concentrate in a first main reactor (step 4), and optionally, reacting the concentrate further with nitric acid in one or more secondary reactors to form a slurry (optional step 5); Transferring the slurry from the first main reactor or from one or more optional secondary reactors to a second main reactor having a lower gas pressure to reduce the pressure of the transferred slurry (step 6); Removing the slurry from the second main reactor and cooling the slurry (step 7); Dividing the cooled slurry into two parts, one part containing leached granular β-spodumene, and the other part being a liquid containing LiNO3(aq) and Al(NO3)3(aq) with a small amount of entrained or suspended solid materials. Transferring the part containing the leached granular β-spodumene to a mixer, washing it with high-purity water in the mixer, separating it from the washing water, and then optionally contacting it with an aqueous solution of Na and / or K hydroxide under conditions sufficient to dissolve Li, Al, and SiO2, and then recovering: (i) Li as one or more of Li2CO3, LiOH(aq), LiOH·xH2O (where x = 1, 2, 3, or 6), and / or Li2O·ySiO2 (where y = 1 or 2); (ii) Al as one or more of Al(OH)3, Al2O3·H2O, and Al2O3; and (iii) SiO2, which is retained in (Na,K)2SiO3(aq) and / or as precipitated silica and / or silica gel (step 8); and In the third main reactor, wash water containing LiNO3(aq) and Al(NO3)3(aq) from the mixer is mixed with a liquid portion containing LiNO3(aq) and Al(NO3)3(aq) with a small amount of entrained or suspended solid material, and then the resulting liquid mixture is subjected to one of the following two treatments to initiate the precipitation of "Al(OH)3(s)": (i) heat treatment at a temperature sufficient to decompose Al(NO3)3(aq) in the liquid mixture, or (ii) "(NH4)2CO3 treatment", which involves contacting the liquid mixture containing LiNO3(aq)- and Al(NO3)3(aq) with (NH4)2CO3(aq) and / or (NH4)2CO3(solid) (step 9).

2. The method according to claim 1, further comprising removing the mixture from the third main reactor and separating the mixture into two parts: an Al(OH)3(s)-rich part and a liquid-rich part (step 10).

3. The method according to claim 2, further comprising feeding the Al(OH)3(s) separated in step 10 into a mixer, where the Al(OH)3(s) is mixed with high-purity water and vigorously stirred / agitated in the mixer to produce a slurry, and the slurry is then divided into an Al(OH)3(s)-rich part and a liquid-rich part, and the slurry in the mixer contains about 40 vol% - 70 vol% solids (step 11).

4. The method according to claim 3, further comprising heating the wet Al(OH)3(s)-rich solid material produced in step 11 to a temperature or temperature range above about 100 °C to dehydrate the material and produce one or more forms of well-crystallized Al(OH)3(s) and / or Al2O3(s) (step 12).

5. The method according to claim 4, further comprising mixing the liquids separated in steps 10 and 11 and feeding the mixed liquid into a fourth main reactor, where the treatment options before entering the fourth main reactor include (i) flowing through an evaporator, in which the concentration of dissolved solids increases due to the removal of water, and (ii) compressing the liquid to 1 < P(atm) ≤ about 10 (step 13).

6. The method according to claim 5 further comprises: (a) Combine the liquid in the fourth main reactor with a liquid consisting almost entirely of (NH4)2CO3(aq) dissolved in high-purity water and / or with high-purity (NH4)2CO3(s), wherein the amount of (NH4)2CO3(aq,s) supplied is slightly in excess of the amount required to react away most of the LiNO3(aq) (step 14); and / or (b) Combine the liquid in the fourth main reactor with an NH3-CO2 gas having a composition suitable for reacting with LiNO3(aq) to produce Li2CO3(s), wherein the amount of NH3-CO2 gas supplied is sufficient to react away most of the LiNO3(aq) (step 15); and / or (c) Combine the liquid in the fourth main reactor with any one or more materials that cause (i) the co-production of Li2CO3(s) and NH4NO3(aq) and (ii) the formation and retention of (NH4)2CO3(aq) under the conditions of about 25 ≤ T (°C) ≤ about 80 and about 1 ≤ P (atm) ≤ about 10 (step 16).

7. The method according to claim 6, further comprising, after transfer to the fifth main reactor, heat-treating the (NH4)2CO3(aq) in the slurry prepared by one or more of steps 14, 15, and 16 such that almost all of the (NH4)2CO3(aq) present is decomposed (step 17).

8. The method according to claim 7, further comprising separating the Li2CO3(s)-LiNO3(aq)-NH4NO3(aq)-H2O(liq)-… slurry produced in step 17 into a Li2CO3(s)-rich portion and a liquid-rich portion (step 19).

9. The method according to claim 8, further comprising feeding the wet Li2CO3(s) separated in step 19 into a mixer, mixing it with high-purity water in the mixer, and then vigorously stirring / agitating to produce a slurry, which is then divided into a Li2CO3(s)-rich portion and a liquid-rich portion (step 20).

10. The method according to claim 9, further comprising mixing the two LiNO3-NH4NO3-H2O(liq)-… liquids separated in steps 19 and 20 and feeding the mixed liquid into the sixth main reactor, wherein the treatment option before entering the reactor is to flow through an evaporator, in which the concentration of the dissolved solids increases due to the removal of water (step 21).

11. The method according to claim 10, further comprising combining the LiNO3-NH4NO3-H2O-liquid in the sixth main reactor with a liquid consisting almost entirely of (Na,K)2CO3(aq) dissolved in high-purity water and / or with high-purity (Na,K)2CO3(s) to cause precipitation of Li2CO3(s) (step 22).

12. The method according to claim 11 further comprises removing the Li2CO3(s)-NH4NO3(aq)-(Na,K)2CO3(aq)H2O(liq)-… slurry generated in step 22 from the sixth main reactor, and then separating the slurry into a Li2CO3(s)-rich portion and a liquid-rich portion (step 23).

13. The method according to claim 12 further comprises feeding the Li2CO3(s) generated in step 23 into a mixer, where it is mixed with high-purity water and then vigorously stirred / agitated to produce a slurry, which is subsequently separated into a Li2CO3(s)-rich portion and a liquid-rich portion (step 24).

14. The method according to claim 13 further comprises drying the wet Li2CO3(s) generated in steps 20 and 24 by heating to a temperature or temperature range between about 80 °C and about 120 °C after optionally removing impurities, to thoroughly dry the material (step 25).

15. The method according to claim 14 further comprises mixing the NH4NO3-(Na,K)NO3-H2O-liquid separated in steps 23 and 24 and feeding the mixed liquid into the seventh main reactor, and the treatment options before entering the reactor are flowing in and out of an evaporator, where the concentration of dissolved solids increases due to the removal of water (step 26).

16. The method according to claim 15 further comprises converting the wet high-purity Li2CO3(s) generated in steps 20 and 24 into high-purity LiOH·H2O(s) by a metathesis reaction: Li2CO3(s)+Ca(OH)2(s)+(2-y)x H2O(liq)→yLiOH(aq)+(2-y)LiOH·x H2O(s)↓+CaCO3(s)↓, and then adjusting the hydration state of LiOH·x H2O(s) to produce LiOH·H2O(s) (step 27).

17. The method according to claim 16 optionally further comprises reacting the substantially leached granular β-spodumene generated in step 8 with an aqueous solution of Na-K hydroxide at about 25 ≤ T (°C) ≤ about 120 and about 1 ≤ P (atm) ≤ about 10 to dissolve the Li and Al and the previously poorly soluble SiO2 contained therein (step 28).

18. The method according to claim 17 further comprises recovering the Li, Al, and SiO2 dissolved in step 28 as follows: (i) Li is recovered as Li2CO3(s) and / or LiOH(aq) and / or Li2O·x H2O(s) (x = 1, 2, 3, 6) and / or Li2O·xSiO2 (x = 1,2); (ii) Al is recovered as Al(OH)3(s) and / or Al2O3·H2O and / or Al2O3(s); and (iii) SiO2 is retained in (Na,K)2SiO3(aq) and / or recovered as precipitated silica and / or silica gel (step 29).

19. The method according to claim 18 further comprises contacting the NH4NO3-(Na,K)NO3-H2O-liquid in the seventh main reactor with (i) an excess of solid magnesium oxide MgO(s), or (ii) an excess of MgO(s) + solid magnesium hydroxide Mg(OH)2(s), or (iii) an excess of Mg(OH)2(s) to produce an aqueous solution of magnesium nitrate Mg(NO3)2(aq), H2O(liq), and NH3(g), wherein if NH4NO3(aq) reacts with MgO(s) or MgO(s) + Mg(OH)2, Mg(NO3)2(aq) and NH3(g) are prepared by all three different types of contact, or if NH4NO3(aq) reacts only with Mg(OH)2(s), then only by the third type of contact (step 30).

20. The method according to claim 19 further comprises mixing in a gas mixer (i) the CO2(g) produced in step 9, (ii) the NH3-CO2 gas produced in step 17, (iii) the NH3(g) formed in step 30, and (iv) the supplied CO2(g) (step 31).

21. The method according to claim 20 further comprises sending the mixed gas produced in step 31 to an eighth main reactor to produce a liquid consisting almost entirely of (NH4)2CO3(aq) dissolved in high-purity water (step 32), wherein optionally water is removed from the (NH4)2CO3-H2O liquid produced in step 32 to precipitate and subsequently separate high-purity (NH4)2CO3(s) (step 33).

22. The method according to claim 21 further comprises recycling the high-purity (NH4)2CO3-H2O liquid produced in step 32 and / or the (NH4)2CO3(s) crystallized in step 33 to one or both of step 9 and step 14 to significantly reduce the net consumption of (NH4)2CO3(aq,s) (step 34).

23. The method according to claim 22 further comprises mixing in a gas mixer (i) the CO2(g) produced in step 9, (ii) the NH3-CO2 gas produced in step 17, (iii) the NH3(g) formed in step 30, and (iv) the supplied CO2(g) to produce a mixed NH3-CO2 gas suitable for step 15 (step 35).

24. The method according to claim 23 further comprises removing the Mg(OH)2(s)-Mg(NO3)2(aq)-(Na,K)NO3(aq)-H2O(liq)-… slurry produced in step 30 from the seventh main reactor and feeding the slurry into an evaporator, in which most of the water in the liquid, plus a small amount of HNO3(aq) formed therein, is separated, and the evaporation time is optionally shortened by vacuum suction (step 36).

25. The method according to claim 24 further comprises additionally removing water from the partially dehydrated slurry produced in step 36, and then devolatilizing it at a temperature or temperature range above the upper limit of the thermal stability of Mg(OH)2(s) and Mg(NO3)2(liq) at a P of about 1 atm (step 37).

26. The method according to claim 25 further comprises feeding the N-O-H gases produced in steps 6, 36 and 37 together with sufficient H2O(liq) into a tenth main reactor, where a large amount of nitric acid is formed (step 38).

27. The method according to claim 26 further comprises mixing the highly dehydrated MgO(s)+(Na,K)NO3(s) produced in step 37 into an unsaturated solution of (Na,K)NO3(aq) dissolved in high-purity water to dissolve (Na,K)NO3(s), while minimizing the conversion of MgO(s) to Mg(OH)2(s), whereupon the slurry is then divided into a MgO(s)-rich portion and a liquid-rich portion (step 39).

28. The method according to claim 27 further comprises dividing the liquid produced in step 39 into two parts, namely part 1 and part 2, and then adding high-purity water in an amount approximately equal to that of part 2 to part 1 (step 40).

29. The method according to claim 28 further comprises removing water from liquid part 2 (step 40) to precipitate (Na,K)NO3(s) (step 41).

30. The method according to claim 29 further comprises producing a large amount of materials containing Li, Al, SiO2 and (Na,K)NO3 in the form of a stable supply of granular concentrates of one or more lithium aluminosilicate minerals from a hard rock source, said one or more lithium aluminosilicate minerals including spodumene: (i) calcining the provided granular spodumene concentrate (a) as specified in step 2, (b) cooling to <100 °C, and then (c) mixing and reacting with nitric acid as described in steps 4 and 5, the initial mass of nitric acid required for steps 4 and 5 being obtained entirely from one or more external sources (step 3), and the amounts thereafter being mainly from steps 6 and 36 - 38; (ii) precipitate Al(OH)3(s) as described in step 9, wash as described in step 11, and finally dehydrate as described in step 12, wherein, In the case of the (NH4)2CO3 treatment option in step 9, ensuring that the initial amount of (NH4)2CO3(aq,s) required for optimal production of Al(OH)3(s) is obtained entirely from one or more external sources, and the amounts thereafter will be mainly from (a) steps 31 and 32 and / or (b) steps 31 - 33, (iii) Li2CO3(s) is precipitated by one or more of the ways determined in Steps 14 - 16, and thereafter, optionally also by the techniques described in Step 22, wherein in Step 14, the initial amount of (NH4)2CO3(aq,s) is obtained entirely from one or more external sources, and the subsequent amounts are mainly from (a) Steps 31 and 32 and / or (b) Steps 31 - 33; in Step 15, the initial amount of NH3-CO2(g)+H2O(liq) is obtained entirely from one or more external sources, and the subsequent amounts will be mainly from Step 31, (iv) As described in Step 27, the Li2CO3(s) formed in one or more of Steps 14 - 16 and optionally subsequent Step 22 is optionally converted to LiOH·H2O(s); (v) Optionally, Steps 39 - 41 are used to recover additional amounts of (Na,K)NO3(aq) and / or (Na,K)NO3(s); (vi) The wet MgO(s) ± Mg(OH)2(s) produced in Step 39 is fed to Step 30 to substantially replace the MgO(s) ± Mg(OH)2(s) consumed in this step; (vii) The liquid portion 1 (Step 40) is mixed into the newly produced amount of highly dehydrated MgO(s) + (Na,K)NO3(s) in Step 37 (Step 42).

31. The method according to claim 1, wherein, Under conditions sufficient to dissolve Li, Al, and SiO2, the washed and separated leached particulate β-spodumene-containing portion is contacted with an aqueous solution of Na and / or K hydroxide, and then recovered: (i) Li as one or more of Li2CO3, LiOH(aq), LiOH·x H2O (where x = 1, 2, 3, or 6), and / or Li2O·y SiO2 (where y = 1 or 2); (ii) Al as one or more of Al(OH)3, Al2O3·H2O, and / or Al2O3; and (iii) SiO2, which remains in (Na,K)2SiO3(aq) and / or as precipitated silica and / or silica gel.

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