Method for converting metal carbonate into metal hydroxide

Abstract

The present disclosure generally relates to the field of electrochemical processes and hydroxide salts production.

Description

METHOD FOR CONVERTING METAL CARBONATE INTO METAL HYDROXIDE TECHNICAL FIELD

[0001] The present disclosure generally relates to the field of electrochemical processes and hydroxide salts production.BACKGROUND

[0002] Climate change is caused by anthropogenic emissions of greenhouse gases to the atmosphere, with carbon dioxide (CO₂) being the most prominent contributor to the greenhouse effect. In order to reduce CO₂ emissions, various technologies to electrify industrial thermal processes to shift energy source from fossil fuels to cleaner electricity, have been developed. The majority of these technologies focus on electrifying industrial processes that consume heat at low temperature of few hundred degrees Celsius, which can be produced by cheap commercial electric heaters utilizing resistance heating.

[0003] The processing of limestone (CaCO₃) into lime (collectively refers to quicklime (CaO) or hydrated lime (Ca(OH)₂)) is an essential process in many industries including cement, pulp and paper, and chemicals, which significantly contributes to global CO₂ emissions. For example, the cement industry is responsible for 8% of the global greenhouse gases emissions, with limestone processing responsible for the majority of these emissions. The commercial process for converting limestone into lime consists of calcining the limestone in temperatures exceeding 900 °C, which causes the limestone to decompose to quicklime and CO2; The quicklime then optionally reacted with water to produce hydrated lime. Due to the high temperatures involved in limestone calcination, commercial electrification of lime production has yet to be implemented at large scale, with attempts to develop electrified lime production processes being at its early stages.

[0004] WO 2007 / 112496 and WO 20222 / 29192 disclose methods for electricity-powered calcination using superheated gas and plasma generated by electric arc, respectively. While these methods provide pathways for calcination electrification, the chemical pathways for lime production is unchanged, implying that the working temperatures of these methods should exceed 900°C. Such temperatures make the energy management more challenging and the structural materials more costly compared to alternative chemical processes employing lower temperature.

[0005] US 11,554,357 describes a method of treating a metal carbonate salt which includes hydrolyzing a metal halide salt to form a hydrohalic acid and a hydroxide salt of the metal in the metal halide salt. The metal includes an alkaline earth metal or an alkali metal. The method includes reacting the hydrohalic acid with the metal carbonate salt, wherein the metal carbonate salt is a carbonate salt of the alkaline earth metal or alkali metal, to form CO2 and the metal halide salt. At least some of the metal halide salt formed from the reacting of the hydrohalic acid with the metal carbonate salt is recycled as at least some of the metal halide salt is hydrolyzed to form the hydrohalic acid and the hydroxide salt.

[0006] WO 2022 / 216741 discloses an electrochemical method for upcycling low-value minerals, including limestone, to various materials, including lime, at low temperature and using electricity and an energy input. This method suggests to dissolve limestone in monovalent acid to form soluble calcium salt solution and then contact the salt solution with base to precipitate hydrated lime, which is filtered and washed. Then, the brine left following precipitation is purified and fed into an electrochemical reactor to regenerate the acid and base used in the method.

[0007] Importantly, the presence of divalent ions, such as calcium, in brines poses a challenge for electrochemical processing because the divalent ions precipitate as hydroxide salt in the alkaline compartments of the electrochemical reactor and lead to its fouling [Mikhaylin and Bazinet, Advances in Colloidal and Interface Science, 2016; Liu and She, ACS ES& T Engineering 2024; Mahmud et al., Desalination 2022].

[0008] There is an unmet need for methods of calcium ion removal from brines of acid-dissolved calcium-containing minerals to enable cost-effective electrochemical production of lime from limestone or other CaCO₃-containing mineral feedstock.SUMMARY OF THE INVENTION

[0009] The present invention provides a method for producing valuable metal hydroxides (e.g., Ca(OH)2, slaked lime) from metal carbonates (e.g., calcium carbonate). In some embodiments, the method comprises acidifying the calcium carbonate to obtain carbon dioxide and a residual Ca+2salt, and basifying the residual calcium salt to generate the Ca(OH)2.

[0010] According to some embodiments, the method further comprises recovery of byproducts obtained during the method for subsequent use. Specifically, the base used for basifying the residual metal salt may be EOH, which may form upon the electrodialysis.

[0011] In particular, the alkali hydroxide base may be further used for the basification step; and the acid formed in the electrodialysis may be further used for the metal carbonate acidification step. Furthermore, the CO2 formed upon the metal carbonate acidification step can be used as a reactant in a following precipitation step.

[0012] The present invention is based, in part, on the unexpected finding of an alternative method to produce Ca(OH)2, which further enable capturing of CO₂ from CaCO₃. through a regenerative process, which requires low energy input. Specifically, the CaCO₃ is subjected to acidification to release the CO₂, preferably as gas, which can be captured as the only other net product of the present reaction cycle, according to some embodiments. Another advantageous feature is that contrary to hydrolysis of the residual calcium salt which is performed at a temperature of 300°C-500°C, the generation of the Ca(OH)2 according to embodiments of the present invention can be performed at temperatures as low as room temperature thereby making the entire method energetically favorable. In addition, it also avoids the production of HCl in a gas phase but instead produces liquid aqueous acid (e.g., hydrochloric acid or nitric acid) which is less environmentally hazardous and easier to handle.

[0013] Thus, the process of the present invention is environmentally friendly, cost effective and minimizes the produced waste through recycling.

[0014] One of the major challenges encountered by the present inventors in the development of the present process is directed to technical difficulties in accomplishing the electrodialysis. Specifically, electrochemical processes are typically sensitive to the presence of contaminants, and it was found that residual Ca+2or other multivalent ions in the liquid composition undergoing electrodialysis can significantly disrupt its performance. Therefore, the challenge was to perform the steps that precede the electrodialysis, in manner that provide a liquid composition (e.g., an aqueous solution) of a monovalent salt EX, that includes minimal calcium or other multivalent metal ions contaminations. This challenge was solved by the present process through reprecipitation of the semi-soluble Ca(OH)2 and other metal hydroxides as CaCOs or other metal carbonates through their reaction with CO2, as the metal carbonates can be conveniently separated from the aqueous solution (e.g., through filtration).

[0015] The terms “method” and “process” are used herein interchangeably. Embodiments that refer to a process may relate to the method and vice versa.

[0016] According to a first aspect, there is provided a method for producing a metal hydroxide from a metal carbonate, the method comprising the steps of:(I) providing a carbonate salt of a metal M, wherein M is:an alkaline earth metal selected from the group consisting of: calcium, magnesium, strontium and barium;a transition metal or post-transition metal, selected from the group consisting of: manganese, cobalt, copper, zinc, lead and bismuth; oran actinide or lanthanide selected from the group consisting of: lanthanum, uranium, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, erbium, holmium, thulium, lutetium and ytterbium;(II) reacting the carbonate salt provided in step (I) with an acid, having the formula HX, wherein X is selected from the group consisting of: halide, NOs', HSO4', HCO3', H2PO3; CH3COO’ and HCOO’,to obtain CO2 and a residual metal salt, which comprises M and at least one X' anion; (III) reacting the residual metal salt with a monovalent base EOH, wherein E is an alkali metal, at a predetermined pH, to form a hydroxide salt of the metal M and an alkali salt EX, thereby resulting in:a first liquid phase comprising the EX and a first portion of the hydroxide salt of the metal M; anda first precipitate comprising a second portion of the hydroxide salt of the metal M; (IV) separating the first precipitate from the first liquid phase;(Va) contacting the separated first liquid phase with CO2, thereby reacting the first portion of the hydroxide salt of the metal M with CO2, to form:a second liquid phase comprising the EX, anda second precipitate comprising the carbonate salt of the metal M;(Vb) separating the second precipitate from the second liquid phase; and(VI) subjecting the separated second liquid phase to electrolysis or electrodialysis thereby regenerating the base of step (III), EOH, and the acid of step (II), HX;wherein the liquid composition provided to step (VI) comprises no more than 500mg / L of the ions of metal M dissolved therein.

[0017] According to some embodiments, the carbonate salt of a metal M is selected from the group consisting of: CaCO3, MgCO3, SrCO3, BaCO3, MnCO3, CoCO3, CuCO3, ZnCO3, PbCO3, (BiO)2CO3, Lu2(CO3)3, La2(CO3)3, UO2CO3, Ce2(CO3)3, Pr2(CO3)3, Nd2(CO3)3, Sm2(CO3)3, Eu2(CO3)3, Gd2(CO3)3, Tb2(CO3)3, Dy2(CO3)3, Er2(CO3)3, Ho2(CO3)3, Tm2(CO3)3, and Yb2(CO3)3. Each possibility represents a separate embodiment of the invention.

[0018] According to some embodiments, M is Ca, Mg, or Mn. According to some embodiments, M is Ca and the carbonate salt provided to step (I) is CaCO3.

[0019] According to some embodiments, the CO2formed in step (II) is in a gas form. According to some embodiments, step (II) comprises isolating and storing at least a portion of the CO2gas. According to some embodiments, the CO2formed in step (II) is in a gas form, and step (II) comprises isolating and storing at least a portion of the CO2gas thus obtained. According to some embodiments, the CO2formed in step (II) is in a gas form, and step (II) comprises isolating and storing the CO2gas thus obtained.

[0020] According to some embodiments, the residual metal salt has the formula MX2. According to some embodiments, the carbonate salt of a metal M has the formula MCO3. According to some embodiments, reacting the MCO3with the acid in step (II) entails carrying out the chemical reaction:MCO3+ 2HX → MX2+ CO2+ H2O.

[0021] According to some embodiments, the residual Ca+2salt has the formula CaX2. According to some embodiments, reacting the CaCO3with the acid in step (II) entails carrying out the chemical reaction:CaCO3+ 2HX CaX2+ CO2+ H2O.

[0022] According to some embodiments, the residual Ca+2salt has the formula CaX2, and reacting the CaCO3with the acid in step (II) entails carrying out the chemical reaction:CaCO3+ 2HX CaX2+ CO2+ H2O.

[0023] According to some embodiments, acid in step (II) is provided as an aqueous solution of HX.

[0024] According to some embodiments, the acid in step (II) is selected from the group consisting of hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, carbonic acid, phosphoric acid, and combinations thereof. Each possibility represents a separate embodiment of the invention. According to some embodiments, the acid in step (II) comprises hydrochloric acid, nitric acid or both. According to some embodiments, the acid in step (II) comprises hydrochloric acid. According to some embodiments, the acid in step (II) comprises nitric acid According to some embodiments, the acid has a concentration in the range of 0.01M to 5M, including each value and sub-range within the specified range.

[0025] According to some embodiments, the acid in step (II) is hydrochloric acid. According to some embodiments, the hydrochloric acid has a concentration in the range of 0.01M to 5M, including each value and sub-range within the specified range. According to some embodiments, the acid in step (II) is nitric acid. According to some embodiments, the nitric acid has a concentration in the range of 0.01M to 5M, including each value and sub-range within the specified range.

[0026] According to some embodiments, the carbonate salt of a metal M has the formula MCO3, and reacting the MCO3 with the acid in step (II) entails carrying out at least one of the following chemical reactions:MCO₃ + 2HCl → CO2+ H2O + MCl2; andMCO3 + 2HNO3CO2+ H2O + M(NO3)2;thereby producing CO₂, and MCl₂ and / or M(NO₃)₂ as the residual metal salt

[0027] According to some embodiments, reacting the CaCO3with the acid in step (II) entails carrying out at least one of the following chemical reactions:CaCO3+ 2HCl → CO2+ H2O + CaCl2; andCaCO3+ 2HNO3CO2+ H2O + Ca(NO3)2;thereby producing CO₂, and CaCl₂ and / or Ca(NO₃)₂ as the residual calcium salt.

[0028] According to some embodiments, the residual metal salt is formed in step (II) as an aqueous solution. According to some embodiments, the residual metal salt is formed in step (II) as an aqueous solution having a concentration of the residual metal salt in the range of 0.005M to 2.5M, including each value and sub-range within the specified range.

[0029] According to some embodiments, the residual Ca+2salt is formed in step (II) as an aqueous solution. According to some embodiments, the residual Ca+2salt is formed in step (II) as an aqueous solution having a concentration of the residual Ca+2salt in the range of 0.005M to 2.5M.

[0030] According to some embodiments, step (III) further comprises providing the monovalent base EOH as an aqueous solution.

[0031] According to some embodiments, step (III) comprises reacting the residual metal salt with excess monovalent base EOH.

[0032] According to some embodiments, step (III) comprises reacting the residual metal salt with the monovalent base EOH at a mol ratio in the range of 1:2 to 1:25. According to some embodiments, step (III) comprises reacting the residual metal salt with the monovalent base EOH at a mol ratio in the range of 1:1.8 to 1:3.3.

[0033] According to some embodiments, the residual metal salt formed in step (II) has the formula MX2, wherein reacting MX2 with EOH in step (III) entails carrying out the following chemical reaction:MX2+ 2EOH → M(OH)2+ 2EX.

[0034] According to some embodiments, the residual metal salt is CaCh and / or Ca(NO3)2, E is Na and reacting the residual metal salt in step (III) entails carrying out at least one of the following chemical reactions:CaCl2+ 2NaOH → Ca(OH)2+ 2NaCl; andCa(NO3)2+ 2NaOH Ca(OH)2+ 2NaNO3,thereby producing Ca(OH)2 and sodium chloride and / or sodium nitrate. Each possibility represents a separate embodiment of the invention.

[0035] According to some embodiments, the predetermined pH is in the range of 7 to 14. According to some embodiments, the predetermined pH is in the range of 9 to 14. According to some embodiments, the predetermined pH is in the range of 12 to 14.

[0036] According to some embodiments, the first liquid phase formed in step (III) is aqueous and has pH in the range of 7 to 14, including each value and sub-range within the specified range. According to some embodiments, the first liquid phase formed in step (III) is aqueous and haspH in the range of 9 to 14. According to some embodiments, the first liquid phase formed in step (III) is aqueous and has pH in the range of 12 to 14.

[0037] According to some embodiments, the first liquid phase formed in step (III) comprises 0.5mg / L to 5000mg / L hydroxide salt of the metal M dissolved therein as the first portion.

[0038] According to some embodiments, a ratio between the first portion of the hydroxide salt of the metal M and the second portion of the hydroxide salt of the metal M is in the range of 0.000002 to 0.2.

[0039] According to some embodiments, E is an alkali metal cation. According to some embodiments, E is Na+.

[0040] According to some embodiments, separating the first precipitate from the first liquid phase in step (IV) comprises filtering the first precipitate from the liquid phase.

[0041] According to some embodiments, the CO2 formed in step (II) is in a gas form. According to some embodiments, step (Va) comprises contacting the separated first liquid phase with a portion of the CO2 formed in step (II). According to some embodiments, the CO2 formed in step (II) is in a gas form, and step (Va) comprises contacting the separated first liquid phase with a portion of the CO2 formed in step (II), or with an aqueous solution comprising bicarbonate ions, carbonate ions, or both, wherein said aqueous solution is formed by contacting a portion of the CO2 formed in step (II) with a portion of the base, EOH, formed in step (IV). Each possibility represents a separate embodiment of the invention.

[0042] According to some embodiments, the first portion of the hydroxide salt of the metal M comprises M(0H)2, wherein reacting the M(0H)2 with the CO2 in step (Va) entails carrying out at least one of the following chemical reaction:M(OH)2+ CO2→ MCO₃ + H2O;M(OH)2+ HCO3⁻ → MCO₃ + H₂O + OH⁻;M(OH)2+ CO₃2-→ MCO₃ + 2OH⁻.

[0043] According to some embodiments, the second precipitate comprises CaCO,.

[0044] According to some embodiments, the second liquid phase comprises no more than 500mg / L metal M in an ionized form dissolved therein. According to some embodiments, the second liquid phase comprises no more than 500mg / L metal M dissolved therein.

[0045] According to some embodiments, the second liquid phase comprises no more than 200mg / L Ca+2dissolved therein.

[0046] According to some embodiments, the second liquid phase comprises 0.1M to 5M EX dissolved therein.

[0047] According to some embodiments, separating the second precipitate from the second liquid phase in step (Vb) comprises filtering the second precipitate from the second liquid phase.

[0048] According to some embodiments, the method further comprises performing steps (I) to (VI), for at least one consecutive cycle, wherein the carbonate salt of the metal M separated in step (Vb) is provided to step (II).

[0049] According to some embodiments, the separated second liquid phase comprises residual dissolved inorganic carbon species. According to some embodiments, the method further comprises step (Vc) of contacting the separated second liquid phase with an acid. According to some embodiments, the acid has the formula HX, wherein X is selected from the group consisting of: halide, NOf, HSCU', HCCh', IfePOs’, CHsCOO' and HCOO'. According to some embodiments, the contacting of step (Vc) entails removing the residual dissolved inorganic carbon species from the separated second liquid phase as CO2. According to some embodiments, the separated second liquid phase comprises residual dissolved inorganic carbon species, and the method further comprises step (Vc) of contacting the separated second liquid phase with an acid, having the formula HX, wherein X is selected from the group consisting of: halide, NOs', HSO4', HCOf, HiPOs', CHsCOO" and HCOO', thereby removing the residual dissolved inorganic carbon species from the separated second liquid phase as CO2.

[0050] According to some embodiments, the acid in step (Vc) is hydrochloric acid or nitric acid.

[0051] According to some embodiments, the method further comprises performing steps (I) to (VI), for at least one consecutive cycle, wherein a portion of the acid formed in step (VI) is provided to consecutive step (Vc).

[0052] According to some embodiments, the method further comprises performing steps (I) to (VI), for at least one consecutive cycle, wherein the CO2 formed in step (Vc) is provided to consecutive step (Va).

[0053] According to some embodiments, the separated second liquid phase provided to step (VI) comprises no more than 500mg / L dissolved inorganic carbon species dissolved therein.

[0054] According to some embodiments, the second liquid phase provided to step (VI) comprises no more than 200mg / L salts of the metal M dissolved therein. According to some embodiments, the second liquid phase provided to step (VI) comprises no more than 200mg / L Ca+2.

[0055] According to some embodiments, EX is ECI or ENO3, and the electrodialysis or electrolysis is according to one of the following schemes:ECl +H2O → HCl + EOHandEENO3+H2O → HNO3+ EOH.

[0056] According to some embodiments, the method further comprises performing steps (I) to (VI), for at least one consecutive cycle. According to some embodiments, the method further comprises performing steps (I) to (VI), for at least one consecutive cycle, wherein the EOH formed in step (VI) is provided as the hydroxide base EOH of consecutive step (III).

[0057] According to some embodiments, X is Cl’ or NOs', E is Na+, and the electrodialysis or electrolysis is according to one of the following schemes:NaCl +H2O → HCl + NaOHorNaNO3+H2O HNO3 + NaOH.

[0058] According to some embodiments, the HX formed in step (VI) is in the form of an aqueous solution.

[0059] According to some embodiments, the method further comprises performing steps (I) to (VI), for at least one consecutive cycle, wherein the HX formed in step (VI) is provided as the acid of consecutive step (II).

[0060] According to some embodiments, each one of the steps of the method is performed at a temperature of 200°C or less. According to some embodiments, each one of the steps of the method is performed at a temperature of 150°C or less. According to some embodiments, each one of the steps of the method is performed at a temperature of 120°C or less.

[0061] A method for producing M(0H)2 from MCO3, the method comprising performing reactions ( l)-(4) a plurality of iterations:(1) MCO3+ 2HX - MX2+ CO2+ H2O;(2) MX2+ 2EOH 2EX + M(0H)2;(3) M(OH)2+ CO2→ MCO₃ + H2O;(4) EX +H2O HX + EOHwhereinM is selected from the group consisting of: Ca+2, Mg+2, Sr+2, Ba+2, Mn+2, Co+2, Cu+2, Zn+2and Pb+2;X is selected from the group consisting of: halide, NCE', HSOx, H2PO3’, HCCE', CPECOO' and HCOO’; andE is a monovalent cation;wherein the reaction of scheme (4) is performed through electrodialysis or electrolysis;wherein the MX2 formed in an iteration of reaction (1) is used as a reactant in an iteration of reaction (2), wherein a portion of the M(0H)2formed in an iteration of reaction (2) is used as a reactant in an iteration of reaction (3), wherein the EX formed in an iteration of reaction (2) is used as a reactant in an iteration of reaction (4); andwherein CO2 formed in an iteration of reaction (1) is used as a reactant in an iteration of reaction (3); and / or MCO3 formed in an iteration of reaction (3) is used as a reactant in an iteration of reaction (1); and / or HX formed in an iteration of reaction (4) is used as a reactant in an iteration of reaction (1); and / or EOH formed in an iteration of reaction (4) is used as a reactant in an iteration of reaction (2).

[0062] According to some embodiments, X is CP or NO3'. According to some embodiments, E is Na+. According to some embodiments, M is Ca+2.

[0063] Certain embodiments of the present disclosure may include some, all, or none of the above advantages. One or more technical advantages may be readily apparent to those skilled in the art from the figures, descriptions and claims included herein. Moreover, while specificadvantages have been enumerated above, various embodiments may include all, some or none of the enumerated advantages.

[0064] In addition to the exemplary aspects and embodiments described above, further aspects and embodiments will become apparent by reference to the figures and by study of the following detailed descriptions.BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Examples illustrative of embodiments are described below with reference to figures attached hereto. In the figures, identical structures, elements or parts that appear in more than one figure are generally labeled with a same numeral in all the figures in which they appear. Alternatively, elements or parts that appear in more than one figure may be labeled with different numerals in the different figures in which they appear. Dimensions of components and features shown in the figures are generally chosen for convenience and clarity of presentation and are not necessarily shown in scale. The figures are listed below.

[0066] Figure 1A is a block diagram illustrating of a method for producing M(0H)2 from MCO3, according to some embodiments.

[0067] Figure IB is a block diagram illustrating of a method for producing Ca(OH)2 from CaCOs. according to some embodiments.

[0068] Figure 1C is a block diagram illustrating of a method for producing Ca(OH)2 from CaCOs. according to some embodiments.

[0069] Figure 2 is a schematic illustration of an electrodialysis device, according to some embodiments.

[0070] Figure 3 is table containing a summary of materials, compositions, processing conditions, and metal-removal efficiencies associated with Examples 1-6.DETAILED DESCRIPTION OF THE INVENTION

[0071] In the following description, various aspects of the disclosure will be described. For the purpose of explanation, specific configurations and details are set forth in order to provide a thorough understanding of the different aspects of the disclosure. However, it will also be apparent to one skilled in the art that the disclosure may be practiced without specific details being presented herein. Furthermore, well-known features may be omitted or simplified in order not to obscure the disclosure.

[0072] The methods of the present invention are suitable for transforming metal carbonates into metal hydroxides.

[0073] According to some embodiments, the present invention provides a method for producing a metal hydroxide from a metal carbonate. According to some embodiments, the method includes the steps as disclosed herein (e.g., steps (I)-(VI), performed once or repeatedly / cyclically ).

[0074] According to some embodiments, the method comprises the steps of:(I) providing a carbonate salt of a metal M, wherein M is:an alkaline earth metal selected from the group consisting of: calcium, magnesium, strontium and barium;a transition metal or post-transition metal, selected from the group consisting of: manganese, cobalt, copper, zinc, lead and bismuth; oran actinide or lanthanide selected from the group consisting of: lanthanum, uranium, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, erbium, holmium, thulium, lutetium and ytterbium;(II) reacting the carbonate salt provided in step (I) with an acid, having the formula HX, wherein X is selected from the group consisting of: halide, NCE', HSOT, HCCE', H2PO3; CH3COO’ and HCOO’,to obtain CO2 and a residual metal salt, which comprises M and at least one X' anion;(III) reacting the residual metal salt with a monovalent base EOH, wherein E is an alkali metal, at a predetermined pH, to form a hydroxide salt of the metal M and an alkali salt EX, thereby resulting in:a first liquid phase comprising the EX and a first portion of the hydroxide salt of the metal M; anda first precipitate comprising a second portion of the hydroxide salt of the metal M;(IV) separating the first precipitate from the first liquid phase;(Va) contacting the separated first liquid phase with CO2, thereby reacting the first portion of the hydroxide salt of the metal M with CO2, to form:a second liquid phase comprising the EX, anda second precipitate comprising the carbonate salt of the metal M; and(Vb) separating the second precipitate from the second liquid phase; and(VI) subjecting the separated second liquid phase to electrolysis or electrodialysis thereby regenerating the base of step (III), EOH, and the acid of step (II), HX;wherein the liquid composition provided to step (VI) comprises no more than 500mg / L salts of the metal M dissolved therein.

[0075] Figure 1A is a schematic illustration of the method 1000 of the present invention, according to some embodiments. Figure IB is a schematic illustration of the present method 1000, performed with specific reactants. Figure 1C is a schematic illustration of the present method 1000, performed with a specific reactants and at specific states of the materials involve, i.e., (g) - gas state, (s) - solid state, (1) - liquid state, or (aq.) -within an aqueous liquid (e.g., dissolved, suspended or dispersed).

[0076] Advantageously, the present method does not require any constant supply of materials or reagents besides the carbonate of the metal M and an energy source.

[0077] Moreover, the present method does not generate any chemical by-products such as acids that are difficult to handle at large scales.

[0078] According to some embodiments, the environmental advantages of the present method are enhanced by electrified regeneration of the hydroxide salt of the metal M from the carbonate salt thereof, and sequestering of carbon dioxide in the gas form. This can be simplified by the following reaction net reaction scheme:MCO3 + H2O M(0H)2+ CO2.

[0079] One of the challenges, which were faced when conducting regeneration of calcium hydroxide from the corresponding carbonate is that this process requires high temperatures that are provided by combustion of fuels. The present invention is based, in part, on the unexpected finding of an alternative method to the methods in the art, occurring at low temperature and usingelectrical input. The carbonate salt, according to some embodiments, can be subjected to acidification (e.g., using an acid HX) to obtain CO2 gas and a residual calcium salt (e.g., CaXi).

[0080] It is to be understood that the terms “Ca+2salt” and “calcium salt”, as used herein are interchangeable. The term "limestone" refers to calcium carbonate, also known as CaCOs. The term "quicklime" refers to calcium oxide, CaO. The term "hydrated lime" refers to calcium hydroxide, also known as Ca(OH)2. The term "lime" is used in its broadest scope covering quicklime (CaO) and hydrated lime (Ca(OH)2).

[0081] The residual calcium salt obtained in the acidification may be in the form of an aqueous composition (e.g., a CaCh solution). It may then be reacted with a base, such as sodium hydroxide (e.g., provided as an aqueous solution) to generate the calcium hydroxide Ca(OH)2. Advantageously, and contrary to hydrolysis of the residual calcium salt which is performed at a temperature of 300°C-500°C, the generation of the Ca(OH)2 according to embodiments of the present invention can be performed at temperatures as low as room temperature thereby making the entire method energetically favorable.

[0082] In addition, a main advantage of the present method is that it enables reuse of all of its side products, such that the net reaction scheme of the entire method is indeed:MCO3 + H2O M(0H)2+ CO2.wherein the CO2 can be captured and the M(0H)2 used as a desired product. A main step that enables the recycling is the electrodialysis, that regenerates the acid, HX, and the hydroxide base EOH from the EX solution. However, accomplishing this step is not trivial as electrodialysis is a process which is highly sensitive to contamination. Thus, it was found that presence of M cation residues from previous steps of the method in the EX solution undergoing electrodialysis prevents its successful completion. As specified above, it was found that dissolved M(0H)2 may be removed through reaction with CO2 and separation of the precipitated MCO3, leaving the liquid phase substantially free from M cations, such as Ca+2.

[0083] Specific reference is now made to step (I) of the present process. According to some embodiments, the present process comprises step (I) of providing carbonate salt of a metal M. According to some embodiments, step (I) is also represented as step 1010 in Figure 1A, Figure 1B and Figure 1C.

[0084] According to some embodiments, M is selected from the group consisting of: an alkaline earth metal, a transition metal, a post-transition metal, an actinide and lanthanide. Eachpossibility represents a separate embodiment of the invention. According to some embodiments, M is selected from the group consisting of: an alkaline earth metal, a transition metal and a posttransition metal. According to some embodiments, M is an alkaline earth metal or a transition metal. According to some embodiments, M is an alkaline earth metal.

[0085] According to some embodiments, the alkaline earth metal is selected from the group consisting of: calcium, magnesium, strontium and barium. Each possibility represents a separate embodiment of the invention. According to some embodiments, the alkaline earth metal is calcium or magnesium. According to some embodiments, the alkaline earth metal is calcium.

[0086] According to some embodiments, the transition metal is selected from the group consisting of: manganese, cobalt, copper and zinc. Each possibility represents a separate embodiment of the invention.

[0087] According to some embodiments, the post-transition metal is selected from the group consisting of: lead and bismuth. Each possibility represents a separate embodiment of the invention.

[0088] According to some embodiments, the lanthanide is selected from the group consisting of: lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium. Each possibility represents a separate embodiment of the invention.

[0089] According to some embodiments, the actinide is uranium.

[0090] According to some embodiments, the carbonate salt of a metal M is selected from the group consisting of: CaCO3, MgCO3, SrCO3, BaCO3, MnCO3, CoCO3, CuCO3, ZnCO3, PbCO3, (BiO)2CO3, LU2(CO3)3, La2(CO3)3, UO2CO3, Ce2(CO3)3, Pr2(CO3)3, Nd2(CO3)3, Sm2(CO3)3, Eu2(CO3)3, Gd2(CO3)3, Tb2(CO3)3, Dy2(CO3)3, Er2(CO3)3, Ho2(CO3)3, Tm2(CO3)3, and Yb2(CO3)3. Each possibility represents a separate embodiment of the invention.

[0091] For the purposes of the present disclosure, the term "providing a carbonate salt of a metal M" refers to the act of supplying or making available either pure carbonate salt of a metal M (e.g., calcium carbonate, magnesium carbonate, manganese carbonate etc.) in its natural or synthetic form, or any composition, mixture, or product that contains carbonate salt of M as an ingredient. This definition encompasses any form (e.g., solid) or concentration of the carbonate salt, and includes but is not limited to, carbonate salt of a metal M provided as a single substance, as part of a formulation, or as an ingredient in a composition or product. Additionally, thecomposition may include more than one compound that falls under the definition of "carbonate salt of a metal M."

[0092] According to some embodiments, providing a carbonate salt of the metal M comprises providing a composition that comprises the carbonate salt of the metal M. According to some embodiments, the composition comprises one or more carbonate salt of the metal M. According to some embodiments, the composition comprises more than one carbonate salt of the metal M. According to some embodiments, the composition comprises at least a first carbonate salt of a first metal M and a second carbonate salt of a second metal M, wherein the first metal M is different from the second metal M. According to some embodiments, the composition is a mineral feedstock composition.

[0093] For the purposes of this disclosure, the term " Mineral Feedstocks" refers to raw mineral materials that are used as primary inputs in industrial processes. This definition includes, but is not limited to, feedstocks composed of calcium carbonate (CaCO3), magnesium carbonate (MgCCh), and / or manganese carbonate (MnCCh), whether in pure form or as part of a mixture or composition. " Mineral Feedstocks" encompass any form or concentration of these minerals, as well as any natural or synthetic variations thereof, that are utilized for the production of goods, energy, or other industrial applications.

[0094] According to some embodiments, the composition comprises no more than 0.5% of the carbonate salt of the metal M. According to some embodiments, the composition comprises at least 1% of the carbonate salt of the metal M. According to some embodiments, the composition comprises at least 5% of the carbonate salt of the metal M. According to some embodiments, the composition comprises at least 10% of the carbonate salt of the metal M. According to some embodiments, the composition comprises at least 25% of the carbonate salt of the metal M. According to some embodiments, the composition comprises at least 50% of the carbonate salt of the metal M. According to some embodiments, the composition comprises at least 75% of the carbonate salt of the metal M.

[0095] It is to be understood that the term “carbonate salt” refers to any salt, which comprises a carbonate moiety, either in an ionic interaction with a cation (e.g., the metal M), multiple cations (e.g., in the case of dolomite which comprises Mg and Ca) or as a coordination complex. The term “carbonate salt” includes hydrates and other solvates, anhydrous salts, and mixtures that contain one or more carbonate salts.

[0096] According to some embodiments, M is a divalent metal cation. According to some embodiments, the carbonate salt has the formula MCO3 or Mi / COs - According to some embodiments, the carbonate salt has the formula MCO3.

[0097] According to some embodiments, M is Ca, Mg, or Mn.

[0098] According to some embodiments, M is Ca and the carbonate salt provided to step (I) is CaCO,. According to some embodiments, M is Mg and the carbonate salt provided to step (I) is MgCO,. According to some embodiments, M is Mn and the carbonate salt provided to step (I) is MnC,.

[0099] According to some embodiments, the carbonate salt of a metal M is provided as a solid. According to some embodiments, the carbonate salt of a metal M is provided as an aqueous composition, which comprises water and the carbonate salt, wherein the carbonate salt is substantially not dissolved in the water. The phrase “substantially not dissolved in the water” refers to a solid material within a composition that also comprises a liquid, wherein most of the solid material is present at the solid state, out of solution, and less than 10%, less than 5%, less than 2% or less than 1% w / w is dissolved. Each possibility represents a separate embodiment of the invention.

[0100] According to some embodiments, the CaCO, is provided as a solid. According to some embodiments, CaCO, is provided as an aqueous composition, which comprises water and CaCO,, wherein the CaCO, is substantially not dissolved in the water.

[0101] Specifically, the aqueous solubility of CaCOs is 13 mg / L at 25°C.

[0102] The term "solution" as used herein broadly refers to a combination, mixture and / or admixture of ingredients having at least one liquid component. Thus, the term "aqueous solution" refers to any solution, in which at least one of its liquid components is water, wherein at least 10% of its weight is water. Aqueous solutions typically include water in greater quantity or volume than a solute. Preferably, "solution" refers broadly to a mixture of miscible substances, where one substance dissolves in a second substance. More preferably, in a solution the essential components are homogeneously mixed and that the components are subdivided to such an extent that there is no appearance of light scattering visible to the naked eye when a one-inch diameter bottle of the mixture is viewed in sunlight. It is also to be understood that water drawn from seas are considered to include a solution, even if the drawn water includes insoluble contaminants mixed or dispersed with the aqueous solution.

[0103] According to some embodiments, the CaCOs is extracted and precipitated from a carbonated water source. For example, carbonated species (e.g. CO2, H2CO3, HCCh', CO3-2) are dissolved in water sources, such as seas. These can be precipitated in the form of water insoluble CaCO3, as detailed in WO 2023 / 187778, which may be the source of the CaCOs of the present method. According to some embodiments, the CaCOs is quarried from natural deposits of calcium carbonate minerals. Calcium carbonate minerals include, but are not limited to, natural limestone and dolomite.

[0104] According to some embodiments, a portion of the carbonate salt of a metal M is provided from the separated second precipitate, separated in step (Vb). According to some embodiments, a portion of the CaCOs is provided from the separated second precipitate, separated in step (Vb).

[0105] According to some embodiments, the CaCOs is in any crystalline or amorphous form including, but not limited to, calcite, aragonite, calcium carbonate monohydrate, amorphous calcium carbonate and the like. Each possibility represents a separate embodiment of the present invention.

[0106] According to some embodiments, the carbonate salt of the metal M provided in step (I) is one constituent within a mixture. The mixture may comprise at least 10%, at least 25%, at least 50%, at least 75%, at least 90%, at least 95%, or at least 99% of the carbonate salt of the metal M, according to some embodiments. According to some embodiments, the mixture comprises a single carbonate salt of the metal M. According to some embodiments, the mixture comprises carbonate salts two or more metals M, wherein each metal M is, individually, as described herein. Thus, according to some embodiments, the carbonate salt of the metal M may be provided not a pure single-component material but is instead part of a mineral feedstock that further comprises other carbonate, oxide, or hydroxide species. Each possibility represents a separate embodiment of the invention. Such feedstocks may include naturally occurring or industrially derived mixtures that comprise, in addition to the MCO3, one or more of MgCCh, MnCCh, FeCCh, Al-containing minerals, silicates, CaO, MgO, hydroxides thereof, or combinations thereof. In these embodiments, the provided composition may contain both target and non-target metals, wherein at least a portion of the non-target metal species are susceptible to selective precipitation under controlled pH conditions, as further defined when relating to step (ID-

[0107] Specific reference is now made to step (II) of the present process. According to some embodiments, the present process comprises step (II) of reacting the carbonate salt provided instep (I) with an acid. According contacting to some embodiments, step (II) is also represented as step 1020 in Figure 1A, Figure 1B and Figure 1C.

[0108] According to some embodiments, the carbonate salt is provided to step (II) as a solid. According to some embodiments, the carbonate salt is provided to step (II) as a solid within an aqueous mixture. According to some embodiments, the carbonate salt is provided to step (II) as a solid, which is (a) suspended within an aqueous suspension, (b) precipitated in water, and / or (c) comprising water absorbed therein. Each possibility represents a separate embodiment of the invention.

[0109] According to some embodiments, the CaCOs is provided to step (II) as a solid. According to some embodiments, the CaCOs is provided to step (II) as a solid within an aqueous mixture. According to some embodiments, the CaCOs is provided to step (II) as a solid, which is (a) suspended within an aqueous suspension, (b) precipitated in water, and / or (c) comprising water absorbed therein. Each possibility represents a separate embodiment of the invention. According to some embodiments, the MgCOs is provided to step (II) as a solid. According to some embodiments, the MgCOs is provided to step (II) as a solid within an aqueous mixture. According to some embodiments, the MgCOs is provided to step (II) as a solid, which is (a) suspended within an aqueous suspension, (b) precipitated in water, and / or (c) comprising water absorbed therein. Each possibility represents a separate embodiment of the invention. According to some embodiments, the MnCOs is provided to step (II) as a solid. According to some embodiments, the MnCOs is provided to step (II) as a solid within an aqueous mixture. According to some embodiments, the MnCOs is provided to step (II) as a solid, which is (a) suspended within an aqueous suspension, (b) precipitated in water, and / or (c) comprising water absorbed therein. Each possibility represents a separate embodiment of the invention.

[0110] According to some embodiments, reacting the carbonate salt with the acid entails forming carbon dioxide. According to some embodiments, reacting the carbonate salt with an acid entails forming a residual metal salt. According to some embodiments, the residual metal salt comprises M. According to some embodiments, the residual metal salt comprises at least one X' anion. According to some embodiments, the residual metal salt is represented by the formula MX2 or M2X3 or MX3. According to some embodiments, the residual metal salt is represented by the formula MX2. According to some embodiments, the residual metal salt has the formula MCI2. According to some embodiments, the residual metal salt has the formula M(NO3)2. According to some embodiments, the residual metal salt is MCI2. According to some embodiments, the residual metal salt is M(NO3)2. The metal M is defined as above.

[0111] According to some embodiments, reacting the CaCO3formed in step (II) with the acid entails forming carbon dioxide. According to some embodiments, reacting the CaCO3formed in step (II) with an acid entails forming a residual calcium salt. According to some embodiments, reacting the MgCO3formed in step (II) with the acid entails forming carbon dioxide. According to some embodiments, reacting the MgCO3formed in step (II) with an acid entails forming a residual magnesium salt. According to some embodiments, reacting the MnCO3formed in step (II) with the acid entails forming carbon dioxide. According to some embodiments, reacting the MnCO3formed in step (II) with an acid entails forming a residual manganese salt.

[0112] According to some embodiments, the residual metal salt comprises a residual Ca+2salt. According to some embodiments, the residual metal salt comprises a residual Mg+2salt. According to some embodiments, the residual metal salt comprises a residual Mn+2salt.

[0113] According to some embodiments, the residual Ca+2salt comprises at least one X' anion. According to some embodiments, the residual Ca+2salt has the formula CaX. According to some embodiments, the residual Ca+2salt has the formula CaCh. According to some embodiments, the residual Ca+2salt is CaCh. According to some embodiments, the residual Ca+2salt has the formula Ca(NO3)2. According to some embodiments, the residual Ca+2salt is Ca(NO3)2. According to some embodiments, the residual Mg+2salt comprises at least one X’ anion. According to some embodiments, the residual Mg+2salt has the formula MgX2. According to some embodiments, the residual Mg+2salt has the formula MgCh. According to some embodiments, the residual Mg+2salt is MgCh. According to some embodiments, the residual Mg+2salt has the formula Mg(NO3)2. According to some embodiments, the residual Mg+2salt is Mg(NO3)2. According to some embodiments, the residual Mn+2salt comprises at least one X' anion. According to some embodiments, the residual Mn+2salt has the formula MnX2. According to some embodiments, the residual Mn+2salt has the formula MnCh. According to some embodiments, the residual Mn+2salt is MnCh. According to some embodiments, the residual Mn+2salt has the formula Mn(NO3)2. According to some embodiments, the residual Mn+2salt is Mn(NO3)2.

[0114] According to some embodiments, the CO2 formed in step (II) is in a gas form. According to some embodiments, step (II) comprises isolating and storing at least a portion of the CO2 gas. According to some embodiments, storing the CO2 gas is also represented as step 1025 in Figure 1A, Figure 1B and Figure 1C. According to some embodiments, the CO2 formedin step (II) is in a gas form, and step (II) comprises isolating and storing at least a portion of the CO2 gas thus obtained.

[0115] According to some embodiments, the CO2 gas is sold as a feedstock for industrial uses. According to some embodiments, the CO2 is permanently sequestered from the carbon cycle by reaction with chemicals or minerals that result in stable solids. According to some embodiments, the CO2 gas is stored in a dedicated container (not shown) or designated storage site (such as underground geological formations, not shown). Suitable containers for CO2 storage, include, but not limited to gas cylinders. Other storage processes include, but are not limited to, condensing the CO2, (e.g., liquidating it) and storing it as a condensed state within depleted oil or gas fields or saline aquifers, or injecting it to geological formations made of silicate rocks, thereby leading to chemical mineralization of the CO2. Each possibility represents a separate embodiment of the invention.

[0116] According to some embodiments, the process comprises performing step (VI), wherein step (VI) entails forming an acid, and wherein a subsequent step (II), which follows step (VI) comprises reacting the carbonate salt of the metal M with the acid formed in step (VI). According to some embodiments, the process comprises performing step (VI), wherein step (VI) entails forming an acid, and wherein a subsequent step (II), which follows step (VI) comprises reacting the CaCO3with the acid formed in step (VI). According to some embodiments, the process comprises performing step (VI), wherein step (VI) entails forming an acid, and wherein a subsequent step (II), which follows step (VI) comprises reacting the MgCO3with the acid formed in step (VI). According to some embodiments, the process comprises performing step (VI), wherein step (VI) entails forming an acid, and wherein a subsequent step (II), which follows step (VI) comprises reacting the MnCO3with the acid formed in step (VI).

[0117] According to some embodiments, the residual metal salt formed in step (II) is in the form of an aqueous mixture. According to some embodiments, the residual metal salt formed in step (II) is in the form of an aqueous solution or suspension. Each possibility represents a separate embodiment of the invention. According to some embodiments, the residual metal salt formed in step (II) is in the form of an aqueous solution. According to some embodiments, the MX2 formed in step (II) is in the form of an aqueous mixture. According to some embodiments, the MX2 formed in step (II) is in the form of an aqueous solution or suspension. Each possibility represents a separate embodiment of the invention. According to some embodiments, the MX2 formed in step (II) is in the form of an aqueous solution. According to some embodiments, the MCI2 formed in step (II) is in the form of an aqueous mixture. According to some embodiments,the MCh formed in step (II) is in the form of an aqueous solution or suspension. Each possibility represents a separate embodiment of the invention. According to some embodiments, the MCh formed in step (II) is in the form of an aqueous solution. According to some embodiments, the M(NO3)2formed in step (II) is in the form of an aqueous mixture. According to some embodiments, the M(NO3)2formed in step (II) is in the form of an aqueous solution or suspension. Each possibility represents a separate embodiment of the invention. According to some embodiments, the M(NO3)2formed in step (II) is in the form of an aqueous solution.

[0118] According to some embodiments, the residual Ca+2salt formed in step (II) is in the form of an aqueous mixture. According to some embodiments, the residual Ca+2salt formed in step (II) is in the form of an aqueous solution or suspension. Each possibility represents a separate embodiment of the invention. According to some embodiments, the residual Ca+2salt formed in step (II) is in the form of an aqueous solution. According to some embodiments, the CaX2 formed in step (II) is in the form of an aqueous mixture. According to some embodiments, the CaX2 formed in step (II) is in the form of an aqueous solution or suspension. Each possibility represents a separate embodiment of the invention. According to some embodiments, the CaX2 formed in step (II) is in the form of an aqueous solution. According to some embodiments, the CaCh formed in step (II) is in the form of an aqueous mixture. According to some embodiments, the CaCh formed in step (II) is in the form of an aqueous solution or suspension. Each possibility represents a separate embodiment of the invention. According to some embodiments, the CaCh formed in step (II) is in the form of an aqueous solution. According to some embodiments, the Ca(NOs)2 formed in step (II) is in the form of an aqueous mixture. According to some embodiments, the Ca(NOs)2 formed in step (II) is in the form of an aqueous solution or suspension. Each possibility represents a separate embodiment of the invention. According to some embodiments, the Ca(NOs)2 formed in step (II) is in the form of an aqueous solution. According to some embodiments, the residual Mg+2salt formed in step (II) is in the form of an aqueous mixture. According to some embodiments, the residual Mg+2salt formed in step (II) is in the form of an aqueous solution or suspension. Each possibility represents a separate embodiment of the invention. According to some embodiments, the residual Mg+2salt formed in step (II) is in the form of an aqueous solution. According to some embodiments, the MgX2 formed in step (II) is in the form of an aqueous mixture. According to some embodiments, the MgX2 formed in step (II) is in the form of an aqueous solution or suspension. Each possibility represents a separate embodiment of the invention. According to some embodiments, the MgX2 formed in step (II) is in the form of an aqueous solution. According to some embodiments, the MgCh formed in step (II) is in the form of an aqueous mixture. According to some embodiments,the MgCh formed in step (II) is in the form of an aqueous solution or suspension. Each possibility represents a separate embodiment of the invention. According to some embodiments, the MgCh formed in step (II) is in the form of an aqueous solution. According to some embodiments, the Mg(NOs)2 formed in step (II) is in the form of an aqueous mixture. According to some embodiments, the Mg(NOs)2 formed in step (II) is in the form of an aqueous solution or suspension. Each possibility represents a separate embodiment of the invention. According to some embodiments, the Mg(NOs)2 formed in step (II) is in the form of an aqueous solution. According to some embodiments, the residual Mn+2salt formed in step (II) is in the form of an aqueous mixture. According to some embodiments, the residual Mn+2salt formed in step (II) is in the form of an aqueous solution or suspension. Each possibility represents a separate embodiment of the invention. According to some embodiments, the residual Mn+2salt formed in step (II) is in the form of an aqueous solution. According to some embodiments, the MnX2 formed in step (II) is in the form of an aqueous mixture. According to some embodiments, the MnX2 formed in step (II) is in the form of an aqueous solution or suspension. Each possibility represents a separate embodiment of the invention. According to some embodiments, the MnX2 formed in step (II) is in the form of an aqueous solution. According to some embodiments, the MnCh formed in step (II) is in the form of an aqueous mixture. According to some embodiments, the MnCh formed in step (II) is in the form of an aqueous solution or suspension. Each possibility represents a separate embodiment of the invention. According to some embodiments, the MnCh formed in step (II) is in the form of an aqueous solution. According to some embodiments, the Mn(NO3)2formed in step (II) is in the form of an aqueous mixture. According to some embodiments, the Mn(NO3)2formed in step (II) is in the form of an aqueous solution or suspension. Each possibility represents a separate embodiment of the invention. According to some embodiments, the Mn(NO3)2formed in step (II) is in the form of an aqueous solution.

[0119] According to some embodiments, the acid of step (II) has the formula HX. According to some embodiments, X is selected from the group consisting of: halide, NO3-, HSO4-, H2PO3-, HCO3-, CH3COO-and HCOO-. Each possibility represents a separate embodiment of the invention. According to some embodiments, X is selected from the group consisting of: halide, NO3-, HSO4-, H2PO3-and HCO3-. According to some embodiments, X is a halide. According to some embodiments, X is Cl-or Br-. According to some embodiments, X is Cl-. According to some embodiments, X is a halide or nitrate. According to some embodiments, X is Cl-or NO3-. According to some embodiments, X is NO3-.

[0120] For the purposes of this disclosure, the phrase "reacting the carbonate salt provided in step (I) with an acid, having the formula HX" refers to the process of subjecting the carbonate salt to a chemical reaction with one or more acids, wherein at least one is represented as HX, according to the present definitions of X. This definition encompasses scenarios where the carbonate salt is reacted with multiple acids, some of which have the formula HX. The acids can be introduced either as a single composition containing a mixture of several acids or as several separate compositions introduced sequentially. The term includes, but is not limited to, any combination of acids, whether reacted simultaneously or in successive steps, as long as the overall process involves the reaction of the carbonate salt with at least one acid having the formula HX. It is, therefore, to be understood that the phrase “residual metal salt, which comprises M and at least one X' anion” refers to any compound that include at least one M and at least one X. For example, the residual metal salt may include MnCh, in which two X moieties are the same (i.e., chloride), MgChNOs), in which two X moieties are different (i.e., chloride and nitrate) and / or Ca(OH)Cl, in which only one of the anions (i.e., chloride), is under the present definition of X, while the other anion (i.e., hydroxide), is not. Thus, chemical representation (e.g., formulas and reaction schemes) that refer to MX2, CaCh, MgX2, MnX2and the like are to be interpreted broadly, so that they include two X moieties, which are the same (e.g., CaCh) or different (e.g., CaCl(NO3)).

[0121] According to some embodiments, the acid of step (II) is selected from the group consisting of: HF, HC1, HBr, HI, HNO3, H2SO4, H3PO3, H2CO3, CH3COOH, HCOH and a combination thereof. Each possibility represents a separate embodiment of the invention. According to some embodiments, the acid is selected from the group consisting of: HF, HC1, HBr, HI, HNO3, H2SO4, H3PO3, H2CO3 and a combination thereof. According to some embodiments, the acid comprises a hydrohalic acid. According to some embodiments, the acid comprises HC1 and / or HBr. According to some embodiments, the acid comprises HC1. According to some embodiments, the acid comprises hydrochloric acid. According to some embodiments, the acid comprises hydrohalic acid and / or nitric acid. According to some embodiments, the acid comprises HC1 and / or HNO3. According to some embodiments, the acid comprises HNO3. According to some embodiments, the acid comprises nitric acid.

[0122] According to some embodiments, the acid is provided as an aqueous mixture. According to some embodiments, the acid is provided as an aqueous solution. According to some embodiments, the acid is an aqueous solution of hydrohalic acid or nitric acid. According to some embodiments, the acid is an aqueous solution of hydrochloric acid or nitric acid. Accordingto some embodiments, the acid is an aqueous solution of hydrohalic acid. According to some embodiments, the acid is an aqueous solution of hydrochloric acid. According to some embodiments, the acid is an aqueous solution of nitric acid.

[0123] According to some embodiments, the acid has a concentration of at least 0.01M. According to some embodiments, the acid has a concentration of no more than 5M. According to some embodiments, the acid has a concentration in the range of 0.01M to 5M, including each value and sub-range within the specified range.

[0124] According to some embodiments, the hydrochloric acid has a HC1 concentration of at least 0.01M. According to some embodiments, the hydrochloric acid has a HC1 concentration of no more than 5M. According to some embodiments, the hydrochloric acid has a HC1 concentration in the range of 0.01M to 5M, including each value and sub-range within the specified range.

[0125] According to some embodiments, the nitric acid has a HNO3 concentration of at least 0.01M. According to some embodiments, the nitric acid has a HNO3 concentration of no more than 5M. According to some embodiments, the nitric acid has a HNO3 concentration in the range of 0.01M to 5M, including each value and sub-range within the specified range.

[0126] According to some embodiments, the residual calcium salt has the formula CaX2. According to some embodiments, the residual calcium salt comprises calcium chloride, calcium nitrate or hydrates thereof. According to some embodiments, the residual calcium salt comprises CaCl2. According to some embodiments, the residual calcium salt comprises CaCl2(H2O)y. According to some embodiments, the residual calcium salt comprises Ca(NO3)2(H2O)x.

[0127] Specifically, calcium nitrate is typically in the form of a hydrate. The most common calcium nitrate hydrate is the tetrahydrate, i.e., x=4. Calcium chloride is common both in the anhydrous form and as a hydrate (e.g., mono- di-, tetra-, hexa-hydrates etc.).

[0128] According to some embodiments, reacting the MCO3 of step (I) with the acid in step (II) entails carrying out the chemical reaction:MCO3+ 2HX → MX2+ CO2+ H2O.

[0129] According to some embodiments, reacting the CaCO3of step (I) with the acid in step (II) entails carrying out the chemical reaction:CaCO3+ 2HX → CaX2+ CO2+ H2O.

[0130] According to some embodiments, reacting the MgCOs of step (I) with the acid in step (II) entails carrying out the chemical reaction:MgCO3+ 2HX → MgX2+ CO2+ H2O.

[0131] According to some embodiments, reacting the MnCO3of step (I) with the acid in step (II) entails carrying out the chemical reaction:MnCO3+ 2HX MnX2+ CO2+ H2O.

[0132] According to some embodiments, reacting the MCO3of step (I) with the acid in step (II) entails carrying out the chemical reaction:MCO3+ 2HCl → MCl2+ CO2+ H2O.

[0133] According to some embodiments, reacting the CaCO3of step (I) with the acid in step (II) entails carrying out the chemical reaction:CaCO3+ 2HCl → CaCl2+ CO2+ H2O.

[0134] According to some embodiments, reacting the MgCO3of step (I) with the acid in step (II) entails carrying out the chemical reaction:MgCO3+ 2HCl → MgCl2+ CO2+ H2O.

[0135] According to some embodiments, reacting the MnCO3of step (I) with the acid in step (II) entails carrying out the chemical reaction:MnCO3+ 2HCl → MnCl2+ CO2+ H2O.

[0136] According to some embodiments, reacting the MCO3of step (I) with the acid in step (II) entails carrying out the chemical reaction:MCO3+ 2HNO3→ CO2+ H2O + M(NO3)2.

[0137] According to some embodiments, reacting the CaCO3of step (I) with the acid in step (II) entails carrying out the chemical reaction:CaCO3+ 2HNO3→ CO2+ H2O + Ca(NO3)2.

[0138] According to some embodiments, reacting the MgCO3of step (I) with the acid in step (II) entails carrying out the chemical reaction:MgCO3+ 2HNO3→ CO2+ H2O + Mg(NO3)2.

[0139] According to some embodiments, reacting the MnCO3of step (I) with the acid in step (II) entails carrying out the chemical reaction:MnCO3+ 2HNO3→ CO2+ H2O + Mn(NO3)2.

[0140] According to some embodiments, reacting the MCO3of step (I) with the acid in step (II) entails carrying out at least one of the following chemical reactions:MCO3+ 2HCl → CO2+ H2O + MCl2;andMCO3+ 2HNO3→ CO2+ H2O + M(NO3)2.

[0141] According to some embodiments, reacting the CaCO3of step (I) with the acid in step (II) entails carrying out at least one of the following chemical reactions:CaCO3+ 2HCl → CO2+ H2O + CaCl2;andCaCO3+ 2HNO3→ CO2+ H2O + Ca(NO3)2.

[0142] According to some embodiments, reacting the MgCO3of step (I) with the acid in step (II) entails carrying out at least one of the following chemical reactions:MgCO3+ 2HCl → CO2+ H2O + MgCl2;andMgCO3+ 2HNO3→ CO2+ H2O + Mg(NO3)2.

[0143] According to some embodiments, reacting the MnCO3of step (I) with the acid in step (II) entails carrying out at least one of the following chemical reactions:MnCO3+ 2HCl → CO2+ H2O + MnCl2;andMnCO3+ 2HNO3→ CO2+ H2O + Mn(NO3)2.

[0144] According to some embodiments, the contacting of step (II) is carried out at a temperature of no more than 200°C. According to some embodiments, the contacting of step (II) is carried out at a temperature of no more than 150°C. According to some embodiments, the contacting of step (II) is carried out at a temperature of no more than 120°C. According to some embodiments, the contacting of step (II) is carried out at a temperature of no more than 100°C. According to some embodiments, the contacting of step (II) is carried out at a temperature of no more than 75°C. According to some embodiments, the contacting of step (II) is carried out at a temperature of no more than 50°C. According to some embodiments, step (II) is carried out at a temperature of no more than 30°C. According to some embodiments, the contacting of step (II) is carried out at room temperature or less. According to some embodiments, the contacting of step (II) is carried out at room temperature.

[0145] According to some embodiments, the reaction of step (II) is carried out at a pH in the range of 0.5 to 4. According to some embodiments, the reaction of step (II) is carried out at a pH in the range of 0.5 to 7. Specifically, it was observed that the reaction may begin at an initially lower pH as low as 0.5 to 5, and at the end of the reaction the pH may elevate to 5.5 to 7.

[0146] According to some embodiments, step (II) comprises contacting at least 0.01 mol of the MCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 0.05 mol of the MCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 0.1 mol of the MCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 0.25 mol of the MCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 0.5 mol of the MCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 0.75 mol of the MCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 0.9 mol of the MCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 0.95 mol of the MCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 1 mol of the MCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 1.1 mol of the MCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 1.25 mol of the MCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 1.5 mol of the MCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 2 mol of the MCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 5 mol of the MCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 2 mol of the MCO3 per 10 mol of the acid. According to some embodiments, step (II) comprises contacting at least 50 mol of the MCO3 per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 100 mol of the MCO3 per 1 mol of the acid.

[0147] According to some embodiments, step (II) comprises contacting at least 0.01 mol of the CaCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 0.05 mol of the CaCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 0.1 mol of the CaCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 0.25 mol of the CaCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 0.5 mol of the CaCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 0.75 mol of the CaCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 0.9 mol of the CaCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 0.95 mol of the CaCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 1 mol of the CaCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 1.1 mol of the CaCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 1.25 mol of the CaCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 1.5 mol of the CaCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 2 mol of the CaCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 5 mol of the CaCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 2 mol of the CaCO3per 10 mol of the acid. According to some embodiments, step (II) comprises contacting at least 50 mol of the CaCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 100 mol of the CaCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 0.01 mol of the MgCCh per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 0.05 mol of the MgCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 0.1 mol of the MgCCh per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 0.25 mol of the MgCCh per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 0.5 mol of the MgCCh per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 0.75 mol of the MgCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 0.9 mol of the MgCCh per 1 mol of the acid. According to some embodiments,step (II) comprises contacting at least 0.95 mol of the MgCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 1 mol of the MgCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 1.1 mol of the MgCOs per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 1.25 mol of the MgCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 1.5 mol of the MgCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 2 mol of the MgCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 5 mol of the MgCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 2 mol of the MgCO3per 10 mol of the acid. According to some embodiments, step (II) comprises contacting at least 50 mol of the MgCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 100 mol of the MgCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 0.01 mol of the MnCOs per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 0.05 mol of the MnCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 0.1 mol of the MnCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 0.25 mol of the MnCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 0.5 mol of the MnCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 0.75 mol of the MnCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 0.9 mol of the MnCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 0.95 mol of the MnCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 1 mol of the MnCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 1.1 mol of the MnCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 1.25 mol of the MnCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 1.5 mol of the MnCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 2 mol of the MnCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 5 mol of the MnCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 2 mol of the MnCO3per 10 mol of the acid. According to some embodiments, step (II) comprises contacting at least 50 mol of the MnCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting at least 100 mol of the MnCO3per 1 mol of the acid.

[0148] According to some embodiments, step (II) comprises contacting no more than 0.01 mol of the MCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 0.05 mol of the MCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 0.1 mol of the MCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 0.25 mol of the MCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 0.5 mol of the MCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 0.75 mol of the MCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 0.9 mol of the MCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 0.95 mol of the MCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 1 mol of the MCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 1.1 mol of the MCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 1.25 mol of the MCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 1.5 mol of the MCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 2 mol of the MCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 5 mol of the MCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 2 mol of the MCO3per 10 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 50 mol of the MCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 100 mol of the MCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting 0.25 mol to 1 mol of the MCO3per 1 mol of the acid.

[0149] According to some embodiments, step (II) comprises contacting no more than 0.01 mol of the CaCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 0.05 mol of the CaCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 0.1 mol of the CaCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 0.25 mol of the CaCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 0.5 mol of the CaCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 0.75 mol of the CaCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 0.9 mol of the CaCO3per 1 mol of the acid. According to some embodiments, step (II) comprisescontacting no more than 0.95 mol of the CaCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 1 mol of the CaCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 1.1 mol of the CaCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 1.25 mol of the CaCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 1.5 mol of the CaCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 2 mol of the CaCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 5 mol of the CaCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 2 mol of the CaCO3per 10 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 50 mol of the CaCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 100 mol of the CaCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting 0.25 mol to 1 mol of the CaCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 0.01 mol of the MgCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 0.05 mol of the MgCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 0.1 mol of the MgCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 0.25 mol of the MgCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 0.5 mol of the MgCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 0.75 mol of the MgCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 0.9 mol of the MgCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 0.95 mol of the MgCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 1 mol of the MgCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 1.1 mol of the MgCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 1.25 mol of the MgCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 1.5 mol of the MgCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 2 mol of the MgCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 5 mol of the MgCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 2 mol of the MgCO3per 10 mol of the acid. According to some embodiments, step(II) comprises contacting no more than 50 mol of the MgCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 100 mol of the MgCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting 0.25 mol to 1 mol of the MgCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 0.01 mol of the MnCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 0.05 mol of the MnCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 0.1 mol of the MnCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 0.25 mol of the MnCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 0.5 mol of the MnCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 0.75 mol of the MnCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 0.9 mol of the MnCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 0.95 mol of the MnCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 1 mol of the MnCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 1.1 mol of the MnCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 1.25 mol of the MnCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 1.5 mol of the MnCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 2 mol of the MnCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 5 mol of the MnCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 2 mol of the MnCO3per 10 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 50 mol of the MnCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting no more than 100 mol of the MnCO3per 1 mol of the acid. According to some embodiments, step (II) comprises contacting 0.25 mol to 1 mol of the MnCO3per 1 mol of the acid

[0150] According to some embodiments, the reaction of step (II) is carried out at a temperature in the range of 0.5°C to 95°C, including each value and sub-range within the specified range. According to some embodiments, the reaction of step (II) is carried out at a temperature in the range of 0.5°C to 80°C.

[0151] According to some embodiments, the reaction of step (II) is carried out at a pressure in the range of 0.1 Bar to 5 Bar, including each value and sub-range within the specified range. According to some embodiments, the reaction of step (II) is carried out at a pressure in the range of 1 Bar to 10 Bar, including each value and sub-range within the specified range. According to some embodiments, the reaction of step (II) is carried out at a pressure in the range of 5 Bar to 50 Bar, including each value and sub-range within the specified range. According to some embodiments, the reaction of step (II) is carried out at a pressure in the range of 15 Bar to 150 Bar, including each value and sub-range within the specified range.

[0152] According to some embodiments, the residual metal salt is formed in step (II) as a liquid composition. According to some embodiments, the residual metal salt is formed in step (II) as a liquid solution. According to some embodiments, the residual metal salt is formed in step (II) as an aqueous composition. According to some embodiments, the residual metal salt is formed in step (II) as an aqueous solution. According to some embodiments, the acid is provided to step (II) as an aqueous solution, and the residual metal salt is formed in step (II) as an aqueous solution.

[0153] According to some embodiments, the residual Ca+2salt is formed in step (II) as a liquid composition. According to some embodiments, the residual Ca+2salt is formed in step (II) as a liquid solution. According to some embodiments, the residual Ca+2salt is formed in step (II) as an aqueous composition. According to some embodiments, the residual Ca+2salt is formed in step (II) as an aqueous solution. According to some embodiments, the acid is provided to step (II) as an aqueous solution, and the residual Ca+2salt is formed in step (II) as an aqueous solution. According to some embodiments, the residual Mg+2salt is formed in step (II) as a liquid composition. According to some embodiments, the residual Mg+2salt is formed in step (II) as a liquid solution. According to some embodiments, the residual Mg+2salt is formed in step (II) as an aqueous composition. According to some embodiments, the residual Mg+2salt is formed in step (II) as an aqueous solution. According to some embodiments, the acid is provided to step (II) as an aqueous solution, and the residual Mg+2salt is formed in step (II) as an aqueous solution. According to some embodiments, the residual Mn+2salt is formed in step (II) as a liquid composition. According to some embodiments, the residual Mn+2salt is formed in step (II) as a liquid solution. According to some embodiments, the residual Mn+2salt is formed in step (II) as an aqueous composition. According to some embodiments, the residual Mn+2salt is formed in step (II) as an aqueous solution. According to some embodiments, the acid is provided to step (II) as an aqueous solution, and the residual Mn+2salt is formed in step (II) as an aqueous solution

[0154] According to some embodiments, the aqueous composition comprises the residual metal salt at a concentration of at least 0.01M. According to some embodiments, the aqueous composition comprises the residual metal salt at a concentration of at least 0.1M. According to some embodiments, the aqueous composition comprises the residual metal salt at a concentration of at least 0.25M. According to some embodiments, the aqueous composition comprises the residual metal salt at a concentration of at least 0.3M. According to some embodiments, the aqueous composition comprises the residual metal salt at a concentration of at least 0.4M. According to some embodiments, the aqueous composition comprises the residual metal salt at a concentration of at least 0.5M. According to some embodiments, the aqueous composition comprises the residual metal salt at a concentration of no more than 5M. According to some embodiments, the aqueous composition comprises the residual metal salt at a concentration of no more than 4M. According to some embodiments, the aqueous composition comprises the residual metal salt at a concentration of no more than 3M. According to some embodiments, the aqueous composition comprises the residual metal salt at a concentration of no more than 2.5M. According to some embodiments, the aqueous composition comprises the residual metal salt at a concentration of no more than 2M. According to some embodiments, the aqueous composition comprises the residual metal salt at a concentration of no more than 1.5M. According to some embodiments, the aqueous composition comprises the residual metal salt at a concentration in the range of 0.01M to 5M, including each value and sub-range within the specified range. According to some embodiments, the aqueous composition comprises the residual metal salt at a concentration in the range of 0.1M to 5M, including each value and sub-range within the specified range. According to some embodiments, the aqueous composition comprises the residual metal salt at a concentration in the range of 0.1M to 3M, including each value and subrange within the specified range. According to some embodiments, the aqueous composition comprises the residual metal salt at a concentration in the range of 0.1M to 2.5M, including each value and sub-range within the specified range.

[0155] According to some embodiments, the aqueous composition comprises the residual Ca+2salt at a concentration of at least 0.01M. According to some embodiments, the aqueous composition comprises the residual Ca+2salt at a concentration of at least 0.1M. According to some embodiments, the aqueous composition comprises the residual Ca+2salt at a concentration of at least 0.25M. According to some embodiments, the aqueous composition comprises the residual Ca+2salt at a concentration of at least 0.3M. According to some embodiments, the aqueous composition comprises the residual Ca+2salt at a concentration of at least 0.4M. According to some embodiments, the aqueous composition comprises the residual Ca+2salt at aconcentration of at least 0.5M. According to some embodiments, the aqueous composition comprises the residual Ca+2salt at a concentration of no more than 5M. According to some embodiments, the aqueous composition comprises the residual Ca+2salt at a concentration of no more than 4M. According to some embodiments, the aqueous composition comprises the residual Ca+2salt at a concentration of no more than 3M. According to some embodiments, the aqueous composition comprises the residual Ca+2salt at a concentration of no more than 2.5M. According to some embodiments, the aqueous composition comprises the residual Ca+2salt at a concentration of no more than 2M. According to some embodiments, the aqueous composition comprises the residual Ca+2salt at a concentration of no more than 1.5M. According to some embodiments, the aqueous composition comprises the residual Ca+2salt at a concentration in the range of 0.01M to 5M, including each value and sub-range within the specified range. According to some embodiments, the aqueous composition comprises the residual Ca+2salt at a concentration in the range of 0.1M to 5M, including each value and sub-range within the specified range. According to some embodiments, the aqueous composition comprises the residual Ca+2salt at a concentration in the range of 0.1M to 3M, including each value and subrange within the specified range. According to some embodiments, the aqueous composition comprises the residual Ca+2salt at a concentration in the range of 0.1M to 2.5M, including each value and sub-range within the specified range. According to some embodiments, the aqueous composition comprises the residual Mg+2salt at a concentration of at least 0.01M. According to some embodiments, the aqueous composition comprises the residual Mg+2salt at a concentration of at least 0.1M. According to some embodiments, the aqueous composition comprises the residual Mg+2salt at a concentration of at least 0.25M. According to some embodiments, the aqueous composition comprises the residual Mg+2salt at a concentration of at least 0.3M. According to some embodiments, the aqueous composition comprises the residual Mg+2salt at a concentration of at least 0.4M. According to some embodiments, the aqueous composition comprises the residual Mg+2salt at a concentration of at least 0.5M. According to some embodiments, the aqueous composition comprises the residual Mg+2salt at a concentration of no more than 5M. According to some embodiments, the aqueous composition comprises the residual Mg+2salt at a concentration of no more than 4M. According to some embodiments, the aqueous composition comprises the residual Mg+2salt at a concentration of no more than 3M. According to some embodiments, the aqueous composition comprises the residual Mg+2salt at a concentration of no more than 2.5M. According to some embodiments, the aqueous composition comprises the residual Mg+2salt at a concentration of no more than 2M. According to some embodiments, the aqueous composition comprises the residual Mg+2salt at aconcentration of no more than 1.5M. According to some embodiments, the aqueous composition comprises the residual Mg+2salt at a concentration in the range of 0.01M to 5M, including each value and sub-range within the specified range. According to some embodiments, the aqueous composition comprises the residual Mg+2salt at a concentration in the range of 0.1M to 5M, including each value and sub-range within the specified range. According to some embodiments, the aqueous composition comprises the residual Mg+2salt at a concentration in the range of 0.1M to 3M, including each value and sub-range within the specified range. According to some embodiments, the aqueous composition comprises the residual Mg+2salt at a concentration in the range of 0.1M to 2.5M, including each value and sub-range within the specified range. According to some embodiments, the aqueous composition comprises the residual Mn+2salt at a concentration of at least 0.01M. According to some embodiments, the aqueous composition comprises the residual Mn+2salt at a concentration of at least 0.1M. According to some embodiments, the aqueous composition comprises the residual Mn+2salt at a concentration of at least 0.25M. According to some embodiments, the aqueous composition comprises the residual Mn+2salt at a concentration of at least 0.3M. According to some embodiments, the aqueous composition comprises the residual Mn+2salt at a concentration of at least 0.4M. According to some embodiments, the aqueous composition comprises the residual Mn+2salt at a concentration of at least 0.5M. According to some embodiments, the aqueous composition comprises the residual Mn+2salt at a concentration of no more than 5M. According to some embodiments, the aqueous composition comprises the residual Mn+2salt at a concentration of no more than 4M. According to some embodiments, the aqueous composition comprises the residual Mn+2salt at a concentration of no more than 3M. According to some embodiments, the aqueous composition comprises the residual Mn+2salt at a concentration of no more than 2.5M. According to some embodiments, the aqueous composition comprises the residual Mn+2salt at a concentration of no more than 2M. According to some embodiments, the aqueous composition comprises the residual Mn+2salt at a concentration of no more than 1.5M. According to some embodiments, the aqueous composition comprises the residual Mn+2salt at a concentration in the range of 0.01M to 5M, including each value and sub-range within the specified range. According to some embodiments, the aqueous composition comprises the residual Mn+2salt at a concentration in the range of 0.1 M to 5M, including each value and subrange within the specified range. According to some embodiments, the aqueous composition comprises the residual Mn+2salt at a concentration in the range of 0.1M to 3M, including each value and sub-range within the specified range. According to some embodiments, the aqueouscomposition comprises the residual Mn+2salt at a concentration in the range of 0.1M to 2.5M, including each value and sub-range within the specified range

[0156] According to some embodiments, the aqueous solution formed in step (II) comprises the residual metal salt at a concentration of at least 0.01M. According to some embodiments, the aqueous solution formed in step (II) comprises the residual metal salt at a concentration of at least 0.1M. According to some embodiments, the aqueous solution formed in step (II) comprises the residual metal salt at a concentration of at least 0.25M. According to some embodiments, the aqueous solution formed in step (II) comprises the residual metal salt at a concentration of at least 0.3M. According to some embodiments, the aqueous solution formed in step (II) comprises the residual metal salt at a concentration of at least 0.4M. According to some embodiments, the aqueous solution formed in step (II) comprises the residual metal salt at a concentration of at least 0.5M. According to some embodiments, the aqueous solution formed in step (II) comprises the residual metal salt at a concentration of no more than 5M. According to some embodiments, the aqueous solution formed in step (II) comprises the residual metal salt at a concentration of no more than 4M. According to some embodiments, the aqueous solution formed in step (II) comprises the residual metal salt at a concentration of no more than 3M. According to some embodiments, the aqueous solution formed in step (II) comprises the residual metal salt at a concentration of no more than 2.5M. According to some embodiments, the aqueous solution formed in step (II) comprises the residual metal salt at a concentration of no more than 2M. According to some embodiments, the aqueous solution formed in step (II) comprises the residual metal salt at a concentration of no more than 1.5M. According to some embodiments, the aqueous solution formed in step (II) comprises the residual metal salt at a concentration in the range of 0.01M to 5M, including each value and sub-range within the specified range. According to some embodiments, the aqueous solution formed in step (II) comprises the residual metal salt at a concentration in the range of 0.1M to 5M, including each value and sub-range within the specified range. According to some embodiments, the aqueous solution formed in step (II) comprises the residual metal salt at a concentration in the range of 0.1M to 3M, including each value and sub-range within the specified range. According to some embodiments, the aqueous solution formed in step (II) comprises the residual metal salt at a concentration in the range of 0.1M to 2.5M, including each value and sub-range within the specified range.

[0157] According to some embodiments, the aqueous solution formed in step (II) comprises the residual Ca+2salt at a concentration of at least 0.01M. According to some embodiments, the aqueous solution formed in step (II) comprises the residual Ca+2salt at a concentration of at least0.1M. According to some embodiments, the aqueous solution formed in step (II) comprises the residual Ca+2salt at a concentration of at least 0.25M. According to some embodiments, the aqueous solution formed in step (II) comprises the residual Ca+2salt at a concentration of at least 0.3M. According to some embodiments, the aqueous solution formed in step (II) comprises the residual Ca+2salt at a concentration of at least 0.4M. According to some embodiments, the aqueous solution formed in step (II) comprises the residual Ca+2salt at a concentration of at least 0.5M. According to some embodiments, the aqueous solution formed in step (II) comprises the residual Ca+2salt at a concentration of no more than 5M. According to some embodiments, the aqueous solution formed in step (II) comprises the residual Ca+2salt at a concentration of no more than 4M. According to some embodiments, the aqueous solution formed in step (II) comprises the residual Ca+2salt at a concentration of no more than 3M. According to some embodiments, the aqueous solution formed in step (II) comprises the residual Ca+2salt at a concentration of no more than 2.5M. According to some embodiments, the aqueous solution formed in step (II) comprises the residual Ca+2salt at a concentration of no more than 2M. According to some embodiments, the aqueous solution formed in step (II) comprises the residual Ca+2salt at a concentration of no more than 1.5M. According to some embodiments, the aqueous solution formed in step (II) comprises the residual Ca+2salt at a concentration in the range of 0.01M to 5M, including each value and sub-range within the specified range. According to some embodiments, the aqueous solution formed in step (II) comprises the residual Ca+2salt at a concentration in the range of 0.1M to 5M, including each value and sub-range within the specified range. According to some embodiments, the aqueous solution formed in step (II) comprises the residual Ca+2salt at a concentration in the range of 0.1M to 3M, including each value and sub-range within the specified range. According to some embodiments, the aqueous solution formed in step (II) comprises the residual Ca+2salt at a concentration in the range of 0.1M to 2.5M, including each value and sub-range within the specified range. According to some embodiments, the aqueous solution formed in step (II) comprises the residual Mg+2salt at a concentration of at least 0.01M. According to some embodiments, the aqueous solution formed in step (II) comprises the residual Mg+2salt at a concentration of at least 0.1M. According to some embodiments, the aqueous solution formed in step (II) comprises the residual Mg+2salt at a concentration of at least 0.25M. According to some embodiments, the aqueous solution formed in step (II) comprises the residual Mg+2salt at a concentration of at least 0.3M. According to some embodiments, the aqueous solution formed in step (II) comprises the residual Mg+2salt at a concentration of at least 0.4M. According to some embodiments, the aqueous solution formed in step (II) comprises the residual Mg+2salt at a concentration of at least 0.5M. According tosome embodiments, the aqueous solution formed in step (II) comprises the residual Mg+2salt at a concentration of no more than 5M. According to some embodiments, the aqueous solution formed in step (II) comprises the residual Mg+2salt at a concentration of no more than 4M. According to some embodiments, the aqueous solution formed in step (II) comprises the residual Mg+2salt at a concentration of no more than 3M. According to some embodiments, the aqueous solution formed in step (II) comprises the residual Mg+2salt at a concentration of no more than 2.5M. According to some embodiments, the aqueous solution formed in step (II) comprises the residual Mg+2salt at a concentration of no more than 2M. According to some embodiments, the aqueous solution formed in step (II) comprises the residual Mg+2salt at a concentration of no more than 1.5M. According to some embodiments, the aqueous solution formed in step (II) comprises the residual Mg+2salt at a concentration in the range of 0.01M to 5M, including each value and sub-range within the specified range. According to some embodiments, the aqueous solution formed in step (II) comprises the residual Mg+2salt at a concentration in the range of 0.1M to 5M, including each value and sub-range within the specified range. According to some embodiments, the aqueous solution formed in step (II) comprises the residual Mg+2salt at a concentration in the range of 0.1M to 3M, including each value and sub-range within the specified range. According to some embodiments, the aqueous solution formed in step (II) comprises the residual Mg+2salt at a concentration in the range of 0.1M to 2.5M, including each value and sub-range within the specified range. According to some embodiments, the aqueous solution formed in step (II) comprises the residual Mn+2salt at a concentration of at least 0.01M. According to some embodiments, the aqueous solution formed in step (II) comprises the residual Mn+2salt at a concentration of at least 0.1M. According to some embodiments, the aqueous solution formed in step (II) comprises the residual Mn+2salt at a concentration of at least 0.25M. According to some embodiments, the aqueous solution formed in step (II) comprises the residual Mn+2salt at a concentration of at least 0.3M. According to some embodiments, the aqueous solution formed in step (II) comprises the residual Mn+2salt at a concentration of at least 0.4M. According to some embodiments, the aqueous solution formed in step (II) comprises the residual Mn+2salt at a concentration of at least 0.5M. According to some embodiments, the aqueous solution formed in step (II) comprises the residual Mn+2salt at a concentration of no more than 5M. According to some embodiments, the aqueous solution formed in step (II) comprises the residual Mn+2salt at a concentration of no more than 4M. According to some embodiments, the aqueous solution formed in step (II) comprises the residual Mn+2salt at a concentration of no more than 3M. According to some embodiments, the aqueous solution formed in step (II) comprises the residual Mn+2salt at a concentration of no more than 2.5M. According to someembodiments, the aqueous solution formed in step (II) comprises the residual Mn+2salt at a concentration of no more than 2M. According to some embodiments, the aqueous solution formed in step (II) comprises the residual Mn+2salt at a concentration of no more than 1.5M. According to some embodiments, the aqueous solution formed in step (II) comprises the residual Mn+2salt at a concentration in the range of 0.01M to 5M, including each value and sub-range within the specified range. According to some embodiments, the aqueous solution formed in step (II) comprises the residual Mn+2salt at a concentration in the range of 0.1M to 5M, including each value and sub-range within the specified range. According to some embodiments, the aqueous solution formed in step (II) comprises the residual Mn+2salt at a concentration in the range of 0.1M to 3M, including each value and sub-range within the specified range. According to some embodiments, the aqueous solution formed in step (II) comprises the residual Mn+2salt at a concentration in the range of 0.1M to 2.5M, including each value and sub-range within the specified range

[0158] According to some embodiments, step (II) further comprises separating contaminants from the formed aqueous composition. Contaminants may include, but not limited to, sand, acidinsoluble particles, multivalent metal ions different than M or Ca+2. The separation may include techniques known in the art, such as filtration, decantation, sedimentation, basification, and precipitation.

[0159] The separation may also include repeating step (III) multiple times at different predetermined pH levels to selectively precipitate different metal ions. In particular, as detailed above with respect to step (I), the carbonate salt of the metal M may be provided as one constituent within a mixture. This carbonate feedstock may comprise one or more non-target metal species. According to some embodiments, the present process comprises a separation of the non-target metal species during step (II). Thus, according to some embodiments, step (II) may further comprise a controlled impurity-precipitation stage.

[0160] According to some embodiments, step (II) comprises introducing the acid HX in an amount that adjusts the pH of the formed mixture to a predetermined intermediate value. According to some embodiments, the predetermined intermediate value is higher than the final pH, to which the mixture reaches before proceeding to step (III). According to some embodiments, the predetermined intermediate pH value is in the range of 5 to 9, including each value and sub-range within the specified range. According to some embodiments, the predetermined intermediate pH value is in the range of 6 to 8. According to some embodiments, the intermediate pH value is such that at which at least a portion of the non-target ions areinsoluble or sparingly soluble. According to some embodiments, upon reaching the predetermined intermediate pH value, one or more non-target salts precipitate from the mixture. According to some embodiments, the one or more non-target salts are selected from the group consisting of oxides, hydroxide, sulphates and phosphates and carbonates of: iron, aluminum, CaSO4and calcium phosphate. According to some embodiments, step (II) further comprises separating the one or more non-target salts from the mixture. According to some embodiments, this impurity-precipitation stage may be carried out within an impurity precipitator. This may be achieved, according to some embodiments, using any suitable solid-liquid separation technique, including filtration, decantation, or sedimentation. Each possibility represents a separate embodiment of the invention. The remaining aqueous phase may then undergo further acidification in step (II) to complete dissolution of the carbonate mixture and form the residual metal salt MX2.

[0161] According to some embodiments, at least a portion of the CO2 obtained in step (II) is provided to step (Va).

[0162] According to some embodiments, the residual metal salt obtained in step (II) is provided to step (III)

[0163] According to some embodiments, the reaction of step (II) is carried out in a vessel comprising polymeric walls.

[0164] Specific reference is now made to step (III) of the present process. According to some embodiments, the present process comprises step (III) of reacting the residual metal salt with a base. According to some embodiments, step (III) is also represented as step 1030 in Figure 1A, Figure 1B and Figure 1C.

[0165] According to some embodiments, the residual metal salt is a calcium salt. According to some embodiments, the residual metal salt is CaX2. According to some embodiments, the residual metal salt is CaCh. According to some embodiments, the residual metal salt is Ca(NOs)2. According to some embodiments, the residual metal salt is a magnesium salt. According to some embodiments, the residual metal salt is MgX2. According to some embodiments, the residual metal salt is MgCh. According to some embodiments, the residual metal salt is Mg(NOs)2. According to some embodiments, the residual metal salt is a manganese salt. According to some embodiments, the residual metal salt is MnX2. According to some embodiments, the residual metal salt is MnCh. According to some embodiments, the residualmetal salt is Mn(NO3)2. According to some embodiments, reacting the residual metal salt with the EOH is performed in the presence of water.

[0166] According to some embodiments, the residual metal salt is provided to step (III) as an aqueous mixture. According to some embodiments, the residual metal salt is provided to step (III) as an aqueous solution or suspension. Each possibility represents a separate embodiment of the invention. According to some embodiments, the residual metal salt is provided to step (III) as an aqueous solution.

[0167] According to some embodiments, the residual calcium salt is provided to step (III) as an aqueous mixture. According to some embodiments, the residual calcium salt is provided to step (III) as an aqueous solution or suspension. Each possibility represents a separate embodiment of the invention. According to some embodiments, the residual calcium salt is provided to step (III) as an aqueous solution. According to some embodiments, the residual magnesium salt is provided to step (III) as an aqueous mixture. According to some embodiments, the residual magnesium salt is provided to step (III) as an aqueous solution or suspension. Each possibility represents a separate embodiment of the invention. According to some embodiments, the residual magnesium salt is provided to step (III) as an aqueous solution. According to some embodiments, the residual manganese salt is provided to step (III) as an aqueous mixture. According to some embodiments, the residual manganese salt is provided to step (III) as an aqueous solution or suspension. Each possibility represents a separate embodiment of the invention. According to some embodiments, the residual manganese salt is provided to step (III) as an aqueous solution.

[0168] According to some embodiments, the residual metal salt has the formula MX2. According to some embodiments, the residual calcium salt has the formula CaX2. The variable X is as detailed herein.

[0169] According to some embodiments, the residual metal salt is MX2. According to some embodiments, MX2 is provided to step (III) as an aqueous mixture. According to some embodiments, MX2 is provided to step (III) as an aqueous solution or suspension. Each possibility represents a separate embodiment of the invention. According to some embodiments, MX2 is provided to step (III) as an aqueous solution. According to some embodiments, MX2 comprises MCI2. According to some embodiments, MCI2 is provided to step (III) as an aqueous mixture. According to some embodiments, MCI2 is provided to step (III) as an aqueous solution or suspension. Each possibility represents a separate embodiment of the invention. According to some embodiments, MCI2 is provided to step (III) as an aqueous solution. According to someembodiments, MX2 comprises M(NOs)2. According to some embodiments, M(N0s)2 is provided to step (III) as an aqueous mixture. According to some embodiments, M(N0s)2 is provided to step (III) as an aqueous solution or suspension. Each possibility represents a separate embodiment of the invention. According to some embodiments, M(N0s)2 is provided to step (III) as an aqueous solution.

[0170] According to some embodiments, the residual metal salt is CaX2. According to some embodiments, CaX2 is provided to step (III) as an aqueous mixture. According to some embodiments, CaX2 is provided to step (III) as an aqueous solution or suspension. Each possibility represents a separate embodiment of the invention. According to some embodiments, CaX2 is provided to step (III) as an aqueous solution. According to some embodiments, CaX2 comprises CaCh. According to some embodiments, CaCh is provided to step (III) as an aqueous mixture. According to some embodiments, CaCh is provided to step (III) as an aqueous solution or suspension. Each possibility represents a separate embodiment of the invention. According to some embodiments, CaCh is provided to step (III) as an aqueous solution. According to some embodiments, CaX2 comprises Ca(NO3)2. According to some embodiments, Ca(NOs)2 is provided to step (III) as an aqueous mixture. According to some embodiments, Ca(NOs)2 is provided to step (III) as an aqueous solution or suspension. Each possibility represents a separate embodiment of the invention. According to some embodiments, Ca(NOs)2 is provided to step (III) as an aqueous solution. According to some embodiments, the residual metal salt is MgX2. According to some embodiments, MgX2 is provided to step (III) as an aqueous mixture. According to some embodiments, MgX2 is provided to step (III) as an aqueous solution or suspension. Each possibility represents a separate embodiment of the invention. According to some embodiments, MgX2 is provided to step (III) as an aqueous solution. According to some embodiments, MgX2 comprises MgCh. According to some embodiments, MgCh is provided to step (III) as an aqueous mixture. According to some embodiments, MgCh is provided to step (III) as an aqueous solution or suspension. Each possibility represents a separate embodiment of the invention. According to some embodiments, MgCh is provided to step (III) as an aqueous solution. According to some embodiments, MgX2 comprises Mg(NOs)2. According to some embodiments, Mg(NOs)2 is provided to step (III) as an aqueous mixture. According to some embodiments, Mg(NOs)2 is provided to step (III) as an aqueous solution or suspension. Each possibility represents a separate embodiment of the invention. According to some embodiments, Mg(NOs)2 is provided to step (III) as an aqueous solution. According to some embodiments, the residual metal salt is MnX2. According to some embodiments, MnX2is provided to step (III) as an aqueous mixture. According to some embodiments, MnX2 is provided to step (III) as anaqueous solution or suspension. Each possibility represents a separate embodiment of the invention. According to some embodiments, MnX is provided to step (III) as an aqueous solution. According to some embodiments, MnX2 comprises MnCh. According to some embodiments, MnCh is provided to step (III) as an aqueous mixture. According to some embodiments, MnCh is provided to step (III) as an aqueous solution or suspension. Each possibility represents a separate embodiment of the invention. According to some embodiments, MnCh is provided to step (III) as an aqueous solution. According to some embodiments, MnX comprises Mn(N0s)2. According to some embodiments, Mn(N0s)2 is provided to step (III) as an aqueous mixture. According to some embodiments, Mn(N0s)2 is provided to step (III) as an aqueous solution or suspension. Each possibility represents a separate embodiment of the invention. According to some embodiments, Mn(N0s)2 is provided to step (III) as an aqueous solution

[0171] According to some embodiments, E is a monovalent cation. According to some embodiments, E is a metal monovalent cation. According to some embodiments, E is a monovalent metal cation. According to some embodiments, E is an alkali metal.

[0172] Monovalent metallic cations include, but are not limited to, alkali metal cations (e.g., Li+, Na+, K+), copper (Cu+), silver (Ag+) and the like.

[0173] According to some embodiments, E is an alkali metal cation. According to some embodiments, E is Na+or K+. Each possibility represents a separate embodiment of the invention. According to some embodiments, E is Na+.

[0174] According to some embodiments, EOH is provided to step (III) as a liquid mixture. According to some embodiments, EOH is provided to step (III) as an aqueous mixture. According to some embodiments, EOH is provided to step (III) as an aqueous solution or suspension. Each possibility represents a separate embodiment of the invention. According to some embodiments, EOH is provided to step (III) as an aqueous solution. According to some embodiments, EOH comprises NaOH. According to some embodiments, the NaOH is provided to step (III) as an aqueous mixture. According to some embodiments, the NaOH is provided to step (III) as an aqueous solution or suspension. Each possibility represents a separate embodiment of the invention. According to some embodiments, the NaOH is provided to step (III) as an aqueous solution.

[0175] According to some embodiments, the EOH liquid mixture comprises a predetermined EOH concentration. According to some embodiments, the EOH aqueous mixture comprises apredetermined EOH concentration. According to some embodiments, the EOH aqueous solution comprises a predetermined EOH concentration. According to some embodiments, the predetermined EOH concentration is at least 0.000001M. According to some embodiments, the predetermined EOH concentration is at least 0.001M. According to some embodiments, the predetermined EOH concentration is at least 0.01M. According to some embodiments, the predetermined EOH concentration is at least 0.1M. According to some embodiments, the predetermined EOH concentration is at least 0.25M. According to some embodiments, the predetermined EOH concentration is at least 0.75M. According to some embodiments, the predetermined EOH concentration is at least IM. According to some embodiments, the predetermined EOH concentration is no more than 10M. According to some embodiments, the predetermined EOH concentration is no more than 5M. According to some embodiments, the predetermined EOH concentration is no more than 4M. According to some embodiments, the predetermined EOH concentration is no more than 3M. According to some embodiments, the predetermined EOH concentration in the range of 0.75M to 5M, including each value and subrange within the specified range. According to some embodiments, the predetermined EOH concentration in the range of 0.5M to 3M. According to some embodiments, the predetermined EOH concentration in the range of 0.01M to IM. According to some embodiments, the predetermined EOH concentration in the range of 0.000001M to 0.01M.

[0176] According to some embodiments, the NaOH liquid mixture comprises a predetermined NaOH concentration. According to some embodiments, the NaOH aqueous mixture comprises a predetermined NaOH concentration. According to some embodiments, the NaOH aqueous solution comprises a predetermined NaOH concentration. According to some embodiments, the predetermined NaOH concentration is at least 0.000001M. According to some embodiments, the predetermined NaOH concentration is at least 0.001M. According to some embodiments, the predetermined NaOH concentration is at least 0.01M. According to some embodiments, the predetermined NaOH concentration is at least 0.1M. According to some embodiments, the predetermined NaOH concentration is at least 0.25M. According to some embodiments, the predetermined NaOH concentration is at least 0.75M. According to some embodiments, the predetermined NaOH concentration is at least IM. According to some embodiments, the predetermined NaOH concentration is no more than 10M. According to some embodiments, the predetermined NaOH concentration is no more than 5M. According to some embodiments, the predetermined NaOH concentration is no more than 4M. According to some embodiments, the predetermined NaOH concentration is no more than 3M. According to some embodiments, the predetermined NaOH concentration in the range of 0.75M to 5M, includingeach value and sub-range within the specified range. According to some embodiments, the predetermined NaOH concentration in the range of 0.5M to 3M. According to some embodiments, the predetermined NaOH concentration in the range of 0.01M to IM. According to some embodiments, the predetermined NaOH concentration in the range of 0.000001M to 0.01M.

[0177] According to some embodiments, the process comprises performing step (VI), wherein step (VI) entails forming a base, and wherein a subsequent step (III), which follows step (VI) comprises reacting the base formed in step (VI). According to some embodiments, the method further comprises performing steps (I) to (VI), for at least one consecutive cycle, wherein the base formed in step (VI) is used as the monovalent base EOH of consecutive step (III).

[0178] As specified above, according to some embodiments, the residual metal salt is obtained in step (II) as an aqueous solution. Thus, according to some embodiments, the residual metal salt is provided to step (III) as an aqueous solution. According to some embodiments, the aqueous solution provided to step (III) comprises residual metal salt at a concentration as detailed herein. For example, according to some embodiments, the aqueous solution provided to step (III) comprises 0.01M to 2.5M CaCh and / or Ca(NOs)2, including each value and sub-range within the specified range.

[0179] According to some embodiments, step (III) comprises reacting the residual metal salt with the EOH at a predetermined pH. It is to be understood that monitoring the pH may be performed while adding the EOH solution into the aqueous solution of the residual metal salt. Thus, according to some embodiments, step (III) comprises adding an aqueous solution of EOH into the aqueous solution comprising the residual metal salt until the pH value of the aqueous solution reaches (e.g., is elevated to) a predetermined pH.

[0180] According to some embodiments, step (III) comprises reacting the residual M+2salt with the EOH at a predetermined pH. It is to be understood that monitoring the pH may be performed while inserting the EOH into the aqueous solution of the residual M+2salt. Thus, according to some embodiments, step (III) comprises inserting the EOH into the aqueous solution comprising the residual M+2salt until the pH value of the aqueous solution reaches (e.g., is elevated to) a predetermined pH. According to some embodiments, step (III) comprises reacting the residual Ca+2salt with the EOH at a predetermined pH. It is to be understood that monitoring the pH may be performed while inserting the EOH into the aqueous solution of the residual Ca+2salt. Thus, according to some embodiments, step (III) comprises inserting the EOH into the aqueous solution comprising the residual Ca+2salt until the pH value of the aqueoussolution reaches (e.g., is elevated to) a predetermined pH. According to some embodiments, step (III) comprises reacting the residual Mg+2salt with the EOH at a predetermined pH. It is to be understood that monitoring the pH may be performed while inserting the EOH into the aqueous solution of the residual Mg+2salt. Thus, according to some embodiments, step (III) comprises inserting the EOH into the aqueous solution comprising the residual Mg+2salt until the pH value of the aqueous solution reaches (e.g., is elevated to) a predetermined pH. According to some embodiments, step (III) comprises reacting the residual Mn+2salt with the EOH at a predetermined pH. It is to be understood that monitoring the pH may be performed while inserting the EOH into the aqueous solution of the residual Mn+2salt. Thus, according to some embodiments, step (III) comprises inserting the EOH into the aqueous solution comprising the residual Mn+2salt until the pH value of the aqueous solution reaches (e.g., is elevated to) a predetermined pH.

[0181] According to some embodiments, step (III) comprises two or more sequential pH-adjustment segments, wherein distinct metal species present in the aqueous solution precipitate at different basic pH thresholds. In such embodiments, the monovalent base EOH is added in a controlled, stepwise manner. For example, when the residual metal salt solution comprises both magnesium- and calcium-containing species, the pH may first be adjusted to a value at which magnesium hydroxide becomes sparingly soluble (e.g., about pH 10.5), thereby precipitating a first hydroxide fraction. Following removal of this first precipitate by any suitable solid-liquid separation technique, the pH of the remaining aqueous phase may be further increased (e.g., to about pH 12.5) to precipitate a second hydroxide fraction, such as calcium hydroxide. Each precipitated portion may be removed, isolated, or collected as desired, while the remaining aqueous phase, comprising the alkali salt EX and any unprecipitated species, proceeds as described herein for step (III).

[0182] According to some embodiments, one or more of the segmented basification stages of step (III) may be carried out within an impurity precipitator. According to some embodiments, the segmented basification of step (III) is particularly applicable when the feedstock originates from dolomite, CaMg(CO3)2. In such embodiments, a first pH-adjustment segment may be performed to about pH 10.5 to selectively precipitate magnesium hydroxide, Mg(OH)2, which is then removed; the pH of the remaining aqueous phase may subsequently be increased (e.g., to about pH 12.5) to precipitate calcium hydroxide, Ca(OH)2. As magnesium hydroxide has a commercial value, it may be isolated and purified for further sale. Each precipitation and separation event may be carried out using any suitable solid-liquid separation technique, andeach recovered hydroxide fraction (e.g., Mg(OH)2 and Ca(OH)2) may be isolated or collected as desired.

[0183] According to some embodiments, such segmented precipitation enables selective recovery of hydroxides of different metals M present in mixed feedstocks, especially when the corresponding hydroxides exhibit distinct solubility minima at different pH values. Each segment, separation event, and resulting hydroxide fraction represents a separate embodiment of the invention.

[0184] According to some embodiments, the predetermined pH is in the range of 7 to 10, including each value and sub-range within the specified range. According to some embodiments, the predetermined pH is in the range of 9 to 14, including each value and subrange within the specified range. According to some embodiments, the predetermined pH is in the range of 12 to 14. According to some embodiments, the predetermined pH is at least 9. According to some embodiments, the predetermined pH is at least 10. According to some embodiments, the predetermined pH is at least 11. According to some embodiments, the predetermined pH is at least 11.25. According to some embodiments, the predetermined pH is at least 11.5. According to some embodiments, the predetermined pH is at least 11.75. According to some embodiments, the predetermined pH is at least 12. According to some embodiments, the predetermined pH is in the range of 13 to 13.5, including each value and sub-range within the specified range.

[0185] According to some embodiments, step (III) comprises reacting the residual metal salt with excess EOH. According to some embodiments, step (III) comprises reacting the residual Ca+2salt with excess EOH. It is to be understood that the term “excess” as used in the context of the ratio of reactants, refers to an amount which is more than the minimal amount required to stoichiometrically complete a full reaction. In the case of the reaction between NaOH and the residual Ca+2salt, the minimal amount of NaOH required to stoichiometrically complete a full reaction is 2 mol NaOH per 1 mol residual Ca+2salt. Therefore, “excess EOH” in the case that M is divalent, refers to more than 2 mols EOH per 1 mol residual M+2salt, and in the case of a trivalent M, excess refers to more than 3 mols monovalent EOH per 1 mol residual M+3salt.

[0186] According to some embodiments, step (III) comprises reacting the residual metal salt with excess EOH at a mol ratio of at least 1:2.01. According to some embodiments, step (III) comprises reacting the residual metal salt with excess EOH at a mol ratio of at least 1:2.05. According to some embodiments, step (III) comprises reacting the residual metal salt with excess EOH at a mol ratio of at least 1:2.1. According to some embodiments, step (III) comprisesreacting the residual metal salt with excess EOH at a mol ratio of at least 1:2.2. According to some embodiments, step (III) comprises reacting the residual metal salt with excess EOH at a mol ratio of at least 1:2.5. According to some embodiments, step (III) comprises reacting the residual metal salt with excess EOH at a mol ratio of at least 1:5. According to some embodiments, step (III) comprises reacting the residual metal salt with excess EOH at a mol ratio of at least 1: 10. According to some embodiments, step (III) comprises reacting the residual metal salt with excess EOH at a mol ratio of at least 1:25.

[0187] According to some embodiments, step (III) comprises reacting the residual Ca+2salt with excess EOH at a mol ratio of at least 1:2.01. According to some embodiments, step (III) comprises reacting the residual Ca+2salt with excess EOH at a mol ratio of at least 1:2.05. According to some embodiments, step (III) comprises reacting the residual Ca+2salt with excess EOH at a mol ratio of at least 1:2.1. According to some embodiments, step (III) comprises reacting the residual Ca+2salt with excess EOH at a mol ratio of at least 1:2.2. According to some embodiments, step (III) comprises reacting the residual Ca+2salt with excess EOH at a mol ratio of at least 1:2.5. According to some embodiments, step (III) comprises reacting the residual Ca+2salt with excess EOH at a mol ratio of at least 1:5. According to some embodiments, step (III) comprises reacting the residual Ca+2salt with excess EOH at a mol ratio of at least 1: 10. According to some embodiments, step (III) comprises reacting the residual Ca+2salt with excess EOH at a mol ratio of at least 1:25. According to some embodiments, step (III) comprises reacting the residual Mg+2salt with excess EOH at a mol ratio of at least 1:2.01. According to some embodiments, step (III) comprises reacting the residual Mg+2salt with excess EOH at a mol ratio of at least 1:2.05. According to some embodiments, step (III) comprises reacting the residual Mg+2salt with excess EOH at a mol ratio of at least 1:2.1. According to some embodiments, step (III) comprises reacting the residual Mg+2salt with excess EOH at a mol ratio of at least 1:2.2. According to some embodiments, step (III) comprises reacting the residual Mg+2salt with excess EOH at a mol ratio of at least 1:2.5. According to some embodiments, step (III) comprises reacting the residual Mg+2salt with excess EOH at a mol ratio of at least 1:5. According to some embodiments, step (III) comprises reacting the residual Mg+2salt with excess EOH at a mol ratio of at least 1:10. According to some embodiments, step (III) comprises reacting the residual Mg+2salt with excess EOH at a mol ratio of at least 1:25. According to some embodiments, step (III) comprises reacting the residual Mn+2salt with excess EOH at a mol ratio of at least 1:2.01. According to some embodiments, step (III) comprises reacting the residual Mn+2salt with excess EOH at a mol ratio of at least 1:2.05. According to some embodiments, step (III) comprises reacting the residual Mn+2salt with excess EOH at amol ratio of at least 1:2.1. According to some embodiments, step (III) comprises reacting the residual Mn+2salt with excess EOH at a mol ratio of at least 1:2.2. According to some embodiments, step (III) comprises reacting the residual Mn+2salt with excess EOH at a mol ratio of at least 1:2.5. According to some embodiments, step (III) comprises reacting the residual Mn+2salt with excess EOH at a mol ratio of at least 1:5. According to some embodiments, step (III) comprises reacting the residual Mn+2salt with excess EOH at a mol ratio of at least 1:10. According to some embodiments, step (III) comprises reacting the residual Mn+2salt with excess EOH at a mol ratio of at least 1:25

[0188] According to some embodiments, reacting EOH in step (III) with the residual metal salt entails forming M(OH)2. According to some embodiments, reacting EOH in step (III) with the residual calcium salt entails forming Ca(OH)2. According to some embodiments, reacting EOH in step (III) with the residual magnesium salt entails forming Mg(OH)2. According to some embodiments, reacting EOH in step (III) with the residual manganese salt entails forming Mn(OH)2. According to some embodiments, reacting EOH in step (III) with the residual metal salt entails forming EX. According to some embodiments, reacting EOH in step (III) with the residual calcium salt entails forming EX. According to some embodiments, reacting EOH in step (III) with the residual magnesium salt entails forming EX. According to some embodiments, reacting EOH in step (III) with the residual manganese salt entails forming EX.

[0189] According to some embodiments, X is Cl’ or NOf. According to some embodiments, EX is ECI or ENO3. Each possibility represents a separate embodiment of the invention. According to some embodiments, EX is NaCl or NaNOs. Each possibility represents a separate embodiment of the invention.

[0190] According to some embodiments, reacting EOH in step (III) with the residual metal salt, MX2, entails carrying out the following chemical reaction:MX2+ 2EOH → M(OH)2+ 2EX.

[0191] According to some embodiments, reacting EOH in step (III) with the residual calcium salt, CaX2, entails carrying out the following chemical reaction:CaX2+ 2EOH → Ca(OH)2+ 2EX.

[0192] According to some embodiments, reacting EOH in step (III) with the residual magnesium salt, MgX2, entails carrying out the following chemical reaction:MgX2+ 2EOH → Mg(OH)2+ 2EX.

[0193] According to some embodiments, reacting EOH in step (III) with the residual manganese salt, MnX2, entails carrying out the following chemical reaction:MnX2+ 2EOH → Mn(OH)2+ 2EX.

[0194] According to some embodiments, E is Na and reacting NaOH in step (III) with the residual metal salt, MX2, entails carrying out the following chemical reaction:MX2+ 2NaOH → M(OH)2+ 2NaX.

[0195] According to some embodiments, E is Na and reacting NaOH in step (III) with the residual calcium salt, CaX2, entails carrying out the following chemical reaction:CaX2+ 2NaOH → Ca(OH)2+ 2NaX.

[0196] According to some embodiments, E is Na and reacting NaOH in step (III) with the residual magnesium salt, MgX2, entails carrying out the following chemical reaction:MgX2+ 2NaOH → Mg(OH)2+ 2NaX.

[0197] According to some embodiments, E is Na and reacting NaOH in step (III) with the residual manganese salt, MnX2, entails carrying out the following chemical reaction:MnX2+ 2NaOH → Mn(OH)2+ 2NaX.

[0198] According to some embodiments, X is Cl, the residual metal salt is MC12and reacting MC12in step (III) with the EOH entails carrying out the following chemical reaction:MCl2+ 2EOH → M(OH)2+ 2ECl.

[0199] According to some embodiments, X is Cl, the residual metal salt is CaCl2and reacting CaCl2in step (III) with the EOH entails carrying out the following chemical reaction:CaCl2+ 2EOH → Ca(OH)2+ 2ECl.

[0200] According to some embodiments, X is Cl, the residual metal salt is MgCl2and reacting MgCl2in step (III) with the EOH entails carrying out the following chemical reaction:MgCl2+ 2EOH → Mg(OH)2+ 2ECl.

[0201] According to some embodiments, X is Cl, the residual metal salt is MnCl2and reacting MnCl2in step (III) with the EOH entails carrying out the following chemical reaction:MnCl2+ 2EOH → Mn(OH)2+ 2ECl.

[0202] According to some embodiments, X is NO3-the residual metal salt is M(NO3)2and reacting M(NO3)2in step (III) with the EOH entails carrying out the following chemical reaction:M(NO3)2+ 2EOH → M(OH)2+ 2ENO3.

[0203] According to some embodiments, X is NO3‘, the residual metal salt is Ca(NO3)2and reacting Ca(NO3)2in step (III) with the EOH entails carrying out the following chemical reaction:Ca(NO3)2+ 2EOH → Ca(OH)2+ 2ENO3.

[0204] According to some embodiments, X is NO3‘, the residual metal salt is Mg(NO3)2and reacting Mg(NO3)2in step (III) with the EOH entails carrying out the following chemical reaction:Mg(NO3)2+ 2EOH → Mg(OH)2+ 2ENO3.

[0205] According to some embodiments, X is NO3‘, the residual metal salt is Mn(NO3)2and reacting Mn(NO3)2in step (III) with the EOH entails carrying out the following chemical reaction:Mn(NO3)2+ 2EOH → Mn(OH)2+ 2ENO3.

[0206] According to some embodiments, E is Na, X is Cl’ or NO3‘, the residual metal salt is M(NO3)2and / or MC12and reacting M(NO3)2and / or MC12in step (III) with the NaOH entails carrying out at least one of the following chemical reactions:MCl2+ 2NaOH → M(OH)2+ 2NaCl; andM(NO3)2+ 2NaOH → M(OH)2+ 2NaNO3. Each possibility represents a separate embodiment of the invention.

[0207] According to some embodiments, M is Ca+2, E is Na, X is Cl’ or NCE', the residual metal salt is Ca(NO3)2and / or CaCl2and reacting Ca(NO3)2and / or CaCl2in step (III) with the NaOH entails carrying out at least one of the following chemical reactions:CaCl2+ 2NaOH → Ca(OH)2+ 2NaCl; andCa(NO3)2+ 2NaOH → Ca(OH)2+ 2NaNO3. Each possibility represents a separate embodiment of the invention.

[0208] According to some embodiments, M is Mg+2, E is Na, X is Cl’ or NCh', the residual metal salt is Mg(NO3)2and / or MgCl2and reacting Mg(NO3)2and / or MgCl2in step (III) with the NaOH entails carrying out at least one of the following chemical reactions:MgCl2+ 2NaOH → Mg(OH)2+ 2NaCl; andMg(NO3)2+ 2NaOH → Mg(OH)2+ 2NaNO3. Each possibility represents a separate embodiment of the invention.

[0209] According to some embodiments, M is Mn+2, E is Na, X is Cl’ or NOs', the residual metal salt is Mn(NO3)2and / or MnCl2and reacting Mn(NO3)2and / or MnCl2in step (III) with the NaOH entails carrying out at least one of the following chemical reactions:MnCl2+ 2NaOH → Mn(OH)2+ 2NaCl; andMn(NO3)2+ 2NaOH → Mn(OH)2+ 2NaNO3. Each possibility represents a separate embodiment of the invention.

[0210] According to some embodiments, the reaction of step (III) entails forming phase separation. According to some embodiments, the reaction of step (III) entails forming a first liquid phase and a first precipitate. According to some embodiments, the first precipitate is substantially insoluble in the liquid phase.

[0211] The phrase “substantially insoluble in the liquid phase” refers to a solid material within a composition that also comprises a liquid, wherein most of the material is present at the solid state, out of solution, and less than 10%, less than 5%, less than 2% or less than 1% w / w is dissolved.

[0212] According to some embodiments, the reaction of step (III) comprises precipitation of a solid from the aqueous solution. According to some embodiments, the reaction of step (III) entails forming a liquid phase and a precipitate.

[0213] According to some embodiments, the first liquid phase comprises the EX. According to some embodiments, the first liquid phase comprises NaCl. According to some embodiments, the first liquid phase comprises EOH. According to some embodiments, the first liquid phase comprises NaOH. According to some embodiments, the first liquid phase comprises unreacted excess EOH. Specifically, it is to be understood that since EOH may be used in excess, according to some embodiments, some of the EOH will remain unreacted. It is also to be understood that since the liquid phase is aqueous, according to some embodiments, and since EOH (such as NaOH and KOH) is water-soluble, the unreacted excess EOH may dissolve into the aqueous phase. According to some embodiments, the first liquid phase is aqueous. According to some embodiments, the first liquid phase comprises an aqueous solution. According to some embodiments, the first aqueous solution comprises the EX and a first portion of the hydroxide salt of the metal M dissolved therein.

[0214] According to some embodiments, the liquid phase comprises a first portion of the hydroxide salt of the metal M. According to some embodiments, the liquid phase comprises a first portion of the M(0H)2. According to some embodiments, the liquid phase comprises a first portion of the Ca(OH)2. According to some embodiments, the liquid phase comprises a first portion of the Mg(OH)2. According to some embodiments, the liquid phase comprises a first portion of the Mn(0H)2. According to some embodiments, the liquid phase comprises a first portion of the hydroxide salt of the metal M dissolved therein. According to some embodiments, the liquid phase comprises a first portion of the M(0H)2 dissolved therein. According to some embodiments, the liquid phase comprises a first portion of the Ca(OH)2 dissolved therein. According to some embodiments, the liquid phase comprises a first portion of the Mg(OH)2 dissolved therein. According to some embodiments, the liquid phase comprises a first portion of the Mn(0H)2 dissolved therein.

[0215] Specifically, as hydroxide salts of the metals of the present invention are partially soluble in water, a portion thereof may be in solution and some may precipitate as a solid. For example, Ca(OH)2 is partially soluble in water, having a solubility of 0.16g Ca(OH)2 per 100g water. As the amount of Ca(OH)2 dissolved in the water may appear as a detrimental contaminant in the electrodialysis step (VI), it is an objective of the present invention to obtain a calciumdepleted solution entering to step (VI). According to some embodiments, the objective is addressed in step (V).

[0216] According to some embodiments, the first liquid phase formed in step (III) has pH in the range of 7 to 10, including each value and sub-range within the specified range. According to some embodiments, the first liquid phase formed in step (III) has pH in the range of 9 to 14, including each value and sub-range within the specified range. According to some embodiments, the first liquid phase formed in step (III) has pH in the range of 11.5 to 14, including each value and sub-range within the specified range. According to some embodiments, the first liquid phase formed in step (III) has pH at least 7. According to some embodiments, the first liquid phase formed in step (III) has pH at least 8. According to some embodiments, the first liquid phase formed in step (III) has pH at least 9. According to some embodiments, the first liquid phase formed in step (III) has pH at least 9.5. According to some embodiments, the first liquid phase formed in step (III) has pH at least 10. According to some embodiments, the first liquid phase formed in step (III) has pH at least 10.5. According to some embodiments, the first liquid phase formed in step (III) has pH at least 11. According to some embodiments, the first liquid phase formed in step (III) has pH at least 11.25. According to some embodiments, the first liquid phase formed in step (III) has pH at least 11.5. According to some embodiments, the first liquid phase formed in step (III) has pH at least 11.75. According to some embodiments, the first liquid phase formed in step (III) has pH at least 12. According to some embodiments, the first liquid phase formed in step (III) has pH in the range of 13 to 13.5, including each value and sub-range within the specified range.

[0217] According to some embodiments, the first aqueous solution formed in step (III) has pH in the range of 7 to 10, including each value and sub-range within the specified range. According to some embodiments, the first aqueous solution formed in step (III) has pH in the range of 9 to 14, including each value and sub-range within the specified range. According to some embodiments, the first aqueous solution formed in step (III) has pH in the range of 11.5 to 14, including each value and sub-range within the specified range. According to some embodiments, the first aqueous solution formed in step (III) has pH at least 7. According to some embodiments, the first aqueous solution formed in step (III) has pH at least 8. According to some embodiments, the first aqueous solution formed in step (III) has pH at least 9. According to some embodiments, the first aqueous solution formed in step (III) has pH at least 9.5. According to some embodiments, the first aqueous solution formed in step (III) has pH at least 10. According to some embodiments, the first aqueous solution formed in step (III) has pH at least 10.5.According to some embodiments, the first aqueous solution formed in step (III) has pH at least 11. According to some embodiments, the first aqueous solution formed in step (III) has pH at least 11.25. According to some embodiments, the first aqueous solution formed in step (III) has pH at least 11.5. According to some embodiments, the first aqueous solution formed in step (III) has pH at least 11.75. According to some embodiments, the first aqueous solution formed in step (III) has pH at least 12. According to some embodiments, the first aqueous solution formed in step (III) has pH in the range of 13 to 13.5, including each value and sub-range within the specified range.

[0218] According to some embodiments, the first liquid phase formed in step (III) comprises 0.1gr / L to 2.5gr / L hydroxide salt of the metal M dissolved therein, including each value and sub-range within the specified range. According to some embodiments, the first liquid phase formed in step (III) comprises 0.0005gr / L to 0.5gr / L hydroxide salt of the metal M dissolved therein, including each value and sub-range within the specified range. According to some embodiments, the first liquid phase formed in step (III) comprises 0.1gr / L to 2.5gr / L M(OH)2dissolved therein, including each value and sub-range within the specified range. According to some embodiments, the first liquid phase formed in step (III) comprises 0.0005gr / L to 0.5gr / L M(0H)2 dissolved therein, including each value and sub-range within the specified range. According to some embodiments, the first liquid phase formed in step (III) comprises 0.1gr / L to 2.5gr / L Ca(OH)2dissolved therein, including each value and sub-range within the specified range. According to some embodiments, the first liquid phase formed in step (III) comprises 0.0005gr / L to 0.5gr / L Mg(OH)2 and / or Mn(0H)2 dissolved therein, including each value and sub-range within the specified range.

[0219] According to some embodiments, the first liquid phase formed in step (III) comprises 0.5gr / L to 600gr / L EX dissolved therein. According to some embodiments, the first liquid phase formed in step (III) comprises 0.5gr / L to 600gr / L NaX dissolved therein. According to some embodiments, the first liquid phase formed in step (III) comprises 0.5gr / L to 320gr / L NaCl dissolved therein dissolved therein. According to some embodiments, the first liquid phase formed in step (III) comprises 0.8gr / L to 600gr / L NaNOs dissolved therein. According to some embodiments, the first liquid phase formed in step (III) comprises 6gr / L to 150gr / L EX dissolved therein. According to some embodiments, the first liquid phase formed in step (III) comprises 6gr / L to 150gr / L NaX dissolved therein. According to some embodiments, the first liquid phase formed in step (III) comprises 6gr / L to 120gr / L NaCl dissolved therein dissolved therein.According to some embodiments, the first liquid phase formed in step (III) comprises 7.5gr / L to 150gr / L NaNOs dissolved therein.

[0220] According to some embodiments, the first precipitate comprises a second portion of the hydroxide salt of the metal M formed in step (III). According to some embodiments, the first precipitate comprises a second portion of the M(0H)2 formed in step (III). According to some embodiments, the first precipitate comprises a second portion of the Ca(OH)2 formed in step (III). According to some embodiments, the first precipitate comprises a second portion of the Mg(OH)2 formed in step (III). According to some embodiments, the first precipitate comprises a second portion of the Mn(0H)2 formed in step (III).

[0221] According to some embodiments, the precipitate formed in step (III) comprises a solid. According to some embodiments, the second portion of the hydroxide salt of M is in a solid form. According to some embodiments, the second portion of the M(0H)2 is in a solid form. According to some embodiments, the second portion of the Ca(OH)2 is in a solid form. According to some embodiments, the second portion of the Mg(OH)2 is in a solid form. According to some embodiments, the second portion of the Mn(0H)2 is in a solid form.

[0222] According to some embodiments, the precipitate formed in step (III) comprises at least 50% hydroxide salt of the metal M w / w. According to some embodiments, the precipitate formed in step (III) comprises at least 60% hydroxide salt of the metal M w / w. According to some embodiments, the precipitate formed in step (III) comprises at least 70% hydroxide salt of the metal M w / w. According to some embodiments, the precipitate formed in step (III) comprises at least 80% hydroxide salt of the metal M w / w. According to some embodiments, the precipitate formed in step (III) comprises at least 90% hydroxide salt of the metal M w / w. According to some embodiments, the precipitate formed in step (III) comprises at least 95% hydroxide salt of the metal M w / w. According to some embodiments, the precipitate formed in step (III) comprises at least 98% hydroxide salt of the metal M w / w. As detailed herein, according to some embodiments, step (I) comprises providing a composition that comprises one or more carbonate salt of the metal M. (e.g., a first carbonate salt of a first metal M and a second carbonate salt of a second metal M, wherein the first metal M is different from the second metal M). It is thus to be understood that the phrase “the precipitate formed in step (III) comprises at least 50% hydroxide salt of the metal M w / w” should be interpreted broadly to include compositions that include, in total, 50% w / w or more hydroxides of any metal M, as described herein, combined.

[0223] According to some embodiments, the precipitate formed in step (III) comprises at least 50% M(0H)2 w / w. According to some embodiments, the precipitate formed in step (III)comprises at least 60% M(0H)2 w / w. According to some embodiments, the precipitate formed in step (III) comprises at least 70% M(0H)2 w / w. According to some embodiments, the precipitate formed in step (III) comprises at least 80% M(0H)2 w / w. According to some embodiments, the precipitate formed in step (III) comprises at least 90% M(0H)2 w / w. According to some embodiments, the precipitate formed in step (III) comprises at least 95% M(0H)2 W / W. According to some embodiments, the precipitate formed in step (III) comprises at least 98% M(0H)2 w / w. According to some embodiments, the precipitate formed in step (III) comprises at least 50% Ca(OH)2 w / w. According to some embodiments, the precipitate formed in step (III) comprises at least 60% Ca(OH)2 w / w. According to some embodiments, the precipitate formed in step (III) comprises at least 70% Ca(OH)2 w / w. According to some embodiments, the precipitate formed in step (III) comprises at least 80% Ca(OH)2 w / w. According to some embodiments, the precipitate formed in step (III) comprises at least 90% Ca(OH)2 w / w. According to some embodiments, the precipitate formed in step (III) comprises at least 95% Ca(OH)2 w / w. According to some embodiments, the precipitate formed in step (III) comprises at least 98% Ca(OH)2 w / w. According to some embodiments, the precipitate formed in step (III) comprises at least 50% Mg(OH)2 w / w. According to some embodiments, the precipitate formed in step (III) comprises at least 60% Mg(OH)2 w / w. According to some embodiments, the precipitate formed in step (III) comprises at least 70% Mg(OH)2 w / w. According to some embodiments, the precipitate formed in step (III) comprises at least 80% Mg(OH)2 w / w. According to some embodiments, the precipitate formed in step (III) comprises at least 90% Mg(OH)2 w / w. According to some embodiments, the precipitate formed in step (III) comprises at least 95% Mg(OH)2 w / w. According to some embodiments, the precipitate formed in step (III) comprises at least 98% Mg(OH)2 w / w. According to some embodiments, the precipitate formed in step (III) comprises at least 50% Mn(0H)2 w / w. According to some embodiments, the precipitate formed in step (III) comprises at least 60% Mn(0H)2 w / w. According to some embodiments, the precipitate formed in step (III) comprises at least 70% Mn(0H)2 w / w. According to some embodiments, the precipitate formed in step (III) comprises at least 80% Mn(0H)2 w / w. According to some embodiments, the precipitate formed in step (III) comprises at least 90% Mn(0H)2 w / w. According to some embodiments, the precipitate formed in step (III) comprises at least 95% Mn(0H)2 w / w. According to some embodiments, the precipitate formed in step (III) comprises at least 98% Mn(0H)2 w / w.

[0224] According to some embodiments, the reacting of step (III) is carried out at a temperature of no more than 200°C. According to some embodiments, the reacting of step (III) is carried out at a temperature of no more than 150°C. According to some embodiments, thereacting of step (III) is carried out at a temperature of no more than 120°C. According to some embodiments, the reacting of step (III) is carried out at a temperature of no more than 100°C. According to some embodiments, the reacting of step (III) is carried out at a temperature of no more than 90°C. According to some embodiments, the reacting of step (III) is carried out at a temperature of no more than 80°C. According to some embodiments, the reacting of step (III) is carried out at a temperature of at least 0°C. According to some embodiments, the reacting of step (III) is carried out at a temperature of at least 5°C. According to some embodiments, the reacting of step (III) is carried out at a temperature in the range of 5°C to 80°C, including each value and sub-range within the specified range. According to some embodiments, reacting of step (III) is carried out at a temperature in the range of 15°C to 60°C, including each value and sub-range within the specified range. According to some embodiments, the reacting of step (III) is carried out at room temperature or less. According to some embodiments, the reaction of step (III) is carried out at a temperature of about 40°C.

[0225] According to some embodiments, a ratio between the first portion of the hydroxide salt of the metal M and the second portion of the hydroxide salt of the metal M is in the range of 0.000002 to 0.2, including each value and sub-range within the specified range.

[0226] According to some embodiments, the reaction of step (III) is carried out in a vessel comprising polymeric walls.

[0227] Specific reference is now made to step (IV) of the present process. According to some embodiments, the present process comprises step (IV) of separating the first precipitate from the first liquid phase. According to some embodiments, step (IV) is also represented as step 1040 in Figure 1A, Figure 1B and Figure 1C.

[0228] Also in Figures 1A-1C, the separated first precipitate is represented as 1042 and the separated first liquid phase is represented as 1044.

[0229] According to some embodiments, separating the first precipitate from the first liquid phase entails separating the first portion of the hydroxide salt of the metal M from the second portion of the hydroxide salt of the metal M. According to some embodiments, separating the first precipitate from the first liquid phase entails separating the first portion of the M(0H)2 from the second portion of the M(0H)2. According to some embodiments, separating the first precipitate from the first liquid phase entails separating the first portion of the Ca(OH)2 from the second portion of the Ca(OH)2. According to some embodiments, separating the first precipitate from the first liquid phase entails separating the first portion of the Mg(OH)2 from the secondportion of the Mg(0H)2. According to some embodiments, separating the first precipitate from the first liquid phase entails separating the first portion of the Mn(0H)2 from the second portion of the Mn (OH)2.

[0230] According to some embodiments, separating the first precipitate from the first liquid phase entails separating the dissolved first portion of the hydroxide salt of the metal M from the solid second portion of the hydroxide salt of the metal M. According to some embodiments, separating the first precipitate from the first liquid phase entails separating the dissolved first portion of the M(0H)2 from the solid second portion of the M(0H)2. According to some embodiments, separating the first precipitate from the first liquid phase entails separating the dissolved first portion of the Ca(OH)2 from the solid second portion of the Ca(OH)2. According to some embodiments, separating the first precipitate from the first liquid phase entails separating the dissolved first portion of the Mg(OH)2 from the solid second portion of the Mg(OH)2. According to some embodiments, separating the first precipitate from the first liquid phase entails separating the dissolved first portion of the Mn(0H)2 from the solid second portion of the Mn(0H)2.

[0231] According to some embodiments, step (IV) comprises isolating the second portion of the hydroxide salt of the metal M. According to some embodiments, step (IV) comprises isolating the second portion of M(0H)2. According to some embodiments, step (IV) comprises isolating the second portion of Ca(OH)2. According to some embodiments, step (IV) comprises isolating the second portion of Mg(OH)2. According to some embodiments, step (IV) comprises isolating the second portion of Mn(0H)2. According to some embodiments, step (IV) comprises isolating the solid second portion of the hydroxide salt of the metal M. According to some embodiments, step (IV) comprises isolating the solid second portion of M(0H)2. According to some embodiments, step (IV) comprises isolating the solid second portion of Ca(OH)2. According to some embodiments, step (IV) comprises isolating the solid second portion of Mg(OH)2. According to some embodiments, step (IV) comprises isolating the solid second portion of Mg(OH)2.

[0232] Separation techniques of solids from liquids are well known in the art. According to some embodiments, the separation includes filtration. According to some embodiments, separating the precipitate comprising the second portion of the hydroxide salt of M from the liquid phase in step (IV) comprises filtering the first precipitate from the first liquid phase. According to some embodiments, separating the precipitate comprising the second portion of the M(0H)2 from the liquid phase in step (IV) comprises filtering the first precipitate from thefirst liquid phase. According to some embodiments, separating the precipitate comprising the second portion of the Ca(0H)2 from the liquid phase in step (IV) comprises filtering the first precipitate from the first liquid phase. According to some embodiments, separating the precipitate comprising the second portion of the Mg(0H)2 from the liquid phase in step (IV) comprises filtering the first precipitate from the first liquid phase. According to some embodiments, separating the precipitate comprising the second portion of the Mn(0H)2 from the liquid phase in step (IV) comprises filtering the first precipitate from the first liquid phase.

[0233] According to some embodiments, the filtering is performed using a filter, which has a cutoff of at least 0.2 micron. According to some embodiments, the cutoff is at least 0.5 micron. According to some embodiments, the cutoff is at least 1 micron. According to some embodiments, the cutoff is no more than 50 micron. According to some embodiments, the cutoff is no more than 25 micron. According to some embodiments, the cutoff is no more than 10 micron. According to some embodiments, the cutoff is in the range of 0.2 micron to 50 micron, including each value and sub-range within the specified range. According to some embodiments, the cutoff is in the range of 1 micron to 10 micron, including each value and subrange within the specified range.

[0234] According to some embodiments, the first separated liquid phase is an aqueous mixture. According to some embodiments, the first separated liquid phase is an aqueous solution or suspension. Each possibility represents a separate embodiment of the invention. According to some embodiments, the first separated liquid phase is an aqueous solution.

[0235] According to some embodiments, the first separated liquid phase comprises water and the first portion of the hydroxide salt of M dissolved therein. According to some embodiments, the first separated liquid phase comprises water and the first portion of M(0H)2 dissolved therein. According to some embodiments, the first separated liquid phase comprises water, and the first portion of Ca(OH)2 dissolved therein. According to some embodiments, the first separated liquid phase comprises water, and the first portion of Mg(OH)2 dissolved therein. According to some embodiments, the first separated liquid phase comprises water, and the first portion of Mn(0H)2 dissolved therein.

[0236] According to some embodiments, the first separated liquid phase comprises EX. According to some embodiments, the first separated liquid phase comprises EX dissolved therein.

[0237] According to some embodiments, the first precipitate comprises the second portion of the hydroxide salt of M as a solid. According to some embodiments, the first precipitate comprises the second portion of M(0H)2 as a solid. According to some embodiments, the first precipitate comprises the second portion of Ca(OH)2 as a solid. According to some embodiments, the first precipitate comprises the second portion of Mg(OH)2 as a solid. According to some embodiments, the first precipitate comprises the second portion of Mn(0H)2 as a solid.

[0238] According to some embodiments, the first separated precipitate comprises the second portion of the hydroxide salt of M as a solid and liquid water. According to some embodiments, the first separated precipitate comprises the second portion of the M(0H)2 as a solid and liquid water. According to some embodiments, the first separated precipitate comprises the second portion of the Ca(OH)2 as a solid and liquid water. According to some embodiments, the first separated precipitate comprises the second portion of the Mg(OH)2 as a solid and liquid water. According to some embodiments, the first separated precipitate comprises the second portion of the Mn(0H)2 as a solid and liquid water. According to some embodiments, a water content within the first precipitate is in the range of 10% to 70% w / w, including each value and subrange within the specified range.

[0239] As used herein, the term "precipitate" refers to solid particles that form in a liquid medium as a result of a chemical reaction, a change in solubility conditions, or other physical or chemical processes that cause a previously dissolved substance to separate as a solid phase. The precipitate may exist as a sedimented solid phase or as a dispersion of fine solid particles suspended in the liquid, forming a slurry. In particular, the term "precipitate" includes fine solid particles of metal hydroxides, such as calcium hydroxide (Ca(OH)2) and other compounds that, upon formation, remain in suspension within an aqueous medium rather than settling immediately, thereby forming a slurry. Similarly, the term "precipitate" also includes solid particles of metal carbonates, such as calcium carbonate (CaCO3) and other compounds that form in an aqueous solution and separate as a distinct solid phase, which may settle out of the solution or remain temporarily suspended before eventual sedimentation. The precipitate may exhibit high water content, which may result from (i) the absorption or retention of water within the solid particles themselves, as in the case of calcium carbonate, and / or (ii) the formation of a slurry in which the precipitate is dispersed in a liquid medium, with the slurry comprising a substantial proportion of water along with the suspended solid particles, as typically in the case of calcium hydroxide. Unless otherwise specified, references to a precipitate herein include bothsettled and suspended solid phases, including slurries containing a high ratio of liquid to solid material.

[0240] According to some embodiments, the water within the precipitate has pH in the range of 7 to 10, including each value and sub-range within the specified range. According to some embodiments, the water within the precipitate has pH in the range of 10 to 14, including each value and sub-range within the specified range. According to some embodiments, the water within the precipitate has pH in the range of 11 to 13, including each value and sub-range within the specified range.

[0241] According to some embodiments, step (IV) further comprises purifying the solid second portion of the hydroxide salt of the metal M. According to some embodiments, step (IV) further comprises washing and / or drying the solid second portion of the hydroxide salt of the metal M. According to some embodiments, step (IV) further comprises purifying the solid second portion of the M(0H)2. According to some embodiments, step (IV) further comprises washing and / or drying the solid second portion of the M(0H)2. According to some embodiments, step (IV) further comprises purifying the solid second portion of the Ca(OH)2. According to some embodiments, step (IV) further comprises washing and / or drying the solid second portion of the Ca(OH)2. According to some embodiments, step (IV) further comprises purifying the solid second portion of the Mg(OH)2. According to some embodiments, step (IV) further comprises washing and / or drying the solid second portion of the Mg(OH)2. According to some embodiments, step (IV) further comprises purifying the solid second portion of the Mn(0H)2. According to some embodiments, step (IV) further comprises washing and / or drying the solid second portion of the Mn(0H)2.

[0242] According to some embodiments, the M(0H)2 is obtained from step (IV) at a purity of at least 50%. As detailed herein, it is to be understood that when referring to embodiments directed to M(0H)2, wherein M comprises more than one metal, the purity is determined as the combined weight of each of the compounds that fall under the definition M(0H)2 (e.g., the combined weight Ca(OH)2 and Mg(OH)2) divided by the total weight of the product. According to some embodiments, the M(0H)2 is obtained from step (IV) at a purity of at least 60%. According to some embodiments, the M(0H)2 is obtained from step (IV) at a purity of at least 70%. According to some embodiments, the M(0H)2 is obtained from step (IV) at a purity of at least 80%. According to some embodiments, the M(0H)2 is obtained from step (IV) at a purity of at least 90%. According to some embodiments, the M(0H)2 is obtained from step (IV) at a purity of at least 95%. According to some embodiments, the M(0H)2 is obtained from step (IV)at a purity of at least 98%. According to some embodiments, the Ca(0H)2 is obtained from step (IV) at a purity of at least 50%. According to some embodiments, the Ca(OH)2 is obtained from step (IV) at a purity of at least 60%. According to some embodiments, the Ca(OH)2 is obtained from step (IV) at a purity of at least 70%. According to some embodiments, the Ca(OH)2 is obtained from step (IV) at a purity of at least 80%. According to some embodiments, the Ca(OH)2 is obtained from step (IV) at a purity of at least 90%. According to some embodiments, the Ca(OH)2 is obtained from step (IV) at a purity of at least 95%. According to some embodiments, the Ca(OH)2 is obtained from step (IV) at a purity of at least 98%. According to some embodiments, the Mg(OH)2 is obtained from step (IV) at a purity of at least 50%. According to some embodiments, the Mg(OH)2 is obtained from step (IV) at a purity of at least 60%. According to some embodiments, the Mg(OH)2 is obtained from step (IV) at a purity of at least 70%. According to some embodiments, the Mg(OH)2 is obtained from step (IV) at a purity of at least 80%. According to some embodiments, the Mg(OH)2 is obtained from step (IV) at a purity of at least 90%. According to some embodiments, the Mg(OH)2 is obtained from step (IV) at a purity of at least 95%. According to some embodiments, the Mg(OH)2 is obtained from step (IV) at a purity of at least 98%. According to some embodiments, the Mn(0H)2 is obtained from step (IV) at a purity of at least 50%. According to some embodiments, the Mn(0H)2 is obtained from step (IV) at a purity of at least 60%. According to some embodiments, the Mn(0H)2 is obtained from step (IV) at a purity of at least 70%. According to some embodiments, the Mn(0H)2 is obtained from step (IV) at a purity of at least 80%. According to some embodiments, the Mn(0H)2 is obtained from step (IV) at a purity of at least 90%. According to some embodiments, the Mn(0H)2 is obtained from step (IV) at a purity of at least 95%. According to some embodiments, the Mn(0H)2 is obtained from step (IV) at a purity of at least 98%.

[0243] According to some embodiments, the first liquid phase has similar properties upon the separation of step (IV) as upon its formation in step (III). Therefore, embodiments directed to the properties of the liquid phase or aqueous solution formed in step (III) may be applied to the separated liquid phase or aqueous solution obtained in step (IV). Such properties include, but not limited to, the concentrations of EX, ECI, ENO3, NaX, NaCl, NaNOs, the hydroxide salt of the metal M, M(0H)2 and / or Ca(OH)2, and the pH.

[0244] Specific reference is now made to step (Va) of the present process. According to some embodiments, the present process comprises step (Va) of contacting the separated first liquid phase with CO2. According to some embodiments, step (Va) is also represented as step 1050 in Figure 1A, Figure 1B and Figure 1C.

[0245] According to some embodiments, the CO2 provided to step (Va) is in a gas form. According to some embodiments, step (Va) comprises contacting the separated first liquid phase with a portion of the CO2 formed in step (II). According to some embodiments, step (Va) comprises contacting the separated first liquid phase with a portion of the CO2 gas formed in step (II). According to some embodiments, step (Va) comprises contacting the separated first liquid phase with a portion of the CO2 formed in step (Vc). According to some embodiments, step (Va) comprises contacting the separated first liquid phase with a portion of the CO2 gas formed in step (Vc). According to some embodiments, step (Va) comprises contacting the separated first liquid phase with a portion of the CO2 gas formed in step (II) and with a portion of the CO2 gas formed in step (Vc).

[0246] According to some embodiments, the contacting of step (Va) may additionally or alternatively be performed using aqueous bicarbonate (EHCO3) or carbonate (E2CO3) species, including sodium bicarbonate formed by contacting at least a portion of the CO2 with the base EOH generated in step (VI). Thus, according to some embodiments, the CO2 provided to step (Va) is in a EHCO3 form or E2CO3 form. According to some embodiments, step (Va) comprises contacting the base, EOH, formed in step (VI) with CO2 to form an aqueous composition comprising EHCO3, E2CO3 or both; and contacting the separated first liquid phase with the aqueous composition, thereby reacting the first portion of the hydroxide salt of the metal M with CO2, to form: the second liquid phase comprising the EX, and the second precipitate comprising the carbonate salt of the metal M. According to some embodiments, step (Va) comprises contacting an aqueous solution of the base, EOH, formed in step (VI) with CO2 to form an aqueous solution comprising EHCO3, E2CO3 or both dissolved therein; and contacting the separated first liquid phase with the aqueous solution, thereby reacting the first portion of the hydroxide salt of the metal M with CO2, to form: the second liquid phase comprising the EX, and the second precipitate comprising the carbonate salt of the metal M. According to some embodiments, at least a portion of the CO2 is provided from the product of step (II). According to some embodiments, at least a portion of the CO2 is provided from the product of step (Vc). According to some embodiments, step (Va) comprises contacting the separated first liquid phase with EHCO3, E2CO3 or both formed by contacting a portion of the CO2 formed in step (II) or step (Vc) with the base formed in step (VI). According to some embodiments, step (Va) comprises contacting the separated first liquid phase with a EHCO3, E2CO3 or both formed by contacting a portion of the CO2 gas formed in step (II) or step (Vc) with the base formed in step (VI).

[0247] According to some embodiments, the separated first liquid phase is provided from step (IV) as an aqueous mixture. According to some embodiments, the separated first liquid phase is provided from step (IV) as an aqueous solution or suspension. Each possibility represents a separate embodiment of the invention. According to some embodiments, the separated first liquid phase is provided from step (IV) as an aqueous solution.

[0248] According to some embodiments, the separated first liquid phase provided from step (IV) to step (Va) comprises the EX. According to some embodiments, the separated first liquid phase provided from step (IV) to step (Va) comprises the NaX. According to some embodiments, the separated first liquid phase provided from step (IV) to step (Va) comprises the NaCl. According to some embodiments, the separated first liquid phase provided from step (IV) to step (Va) comprises the NaNO3. According to some embodiments, the separated first liquid phase provided from step (IV) to step (Va) comprises the EX dissolved therein. According to some embodiments, the separated first liquid phase provided from step (IV) to step (Va) comprises the NaX dissolved therein. According to some embodiments, the separated first liquid phase provided from step (IV) to step (Va) comprises the NaCl dissolved therein. According to some embodiments, the separated first liquid phase provided from step (IV) to step (Va) comprises the NaNCE dissolved therein.

[0249] According to some embodiments, the separated first liquid phase provided from step (IV) comprises the first portion of the hydroxide salt of the metal M and the contacting of step (Va) entails reacting the first portion of the hydroxide salt of the metal M with CO2. According to some embodiments, the separated first liquid phase provided from step (IV) comprises the first portion of the M(0H)2 and the contacting of step (Va) entails reacting the first portion of the M(0H)2 with CO2. According to some embodiments, the separated first liquid phase provided from step (IV) comprises the first portion of the Ca(OH)2 and the contacting of step (Va) entails reacting the first portion of the Ca(OH)2 with CO2. According to some embodiments, the separated first liquid phase provided from step (IV) comprises the first portion of the Mg(OH)2 and the contacting of step (Va) entails reacting the first portion of the Mg(OH)2 with CO2. According to some embodiments, the separated first liquid phase provided from step (IV) comprises the first portion of the Mn(0H)2 and the contacting of step (Va) entails reacting the first portion of the Mn(0H)2 with CO2.

[0250] According to some embodiments, the first portion of the hydroxide salt of the metal M comprises M(0H)2. According to some embodiments, the first portion of the hydroxide salt of the metal M comprises M(0H)2 dissolved within the first separated liquid phase. Accordingto some embodiments, reacting the M(0H)2 with the CO2 in step (Va) entails carrying out one or more of the following chemical reaction:M(OH)2+ CO2→ MCO₃ + H2O;M(OH)2+ HCO3⁻ → MCO₃ + H₂O + OH⁻; andM(OH)2+ CO₃2-→ MCO₃ + 2OH⁻.

[0251] According to some embodiments, the contacting of step (Va) is therefore not limited to gaseous CO2 and encompasses contacting with aqueous carbonate or bicarbonate species, including EHCO3 or E2CO3 provided as described herein.

[0252] According to some embodiments, reacting the M(0H)2 with the CO2 in step (Va) entails carrying out the following chemical reaction:M(0H)2+ CO2MCO3 + H2O.

[0253] According to some embodiments, the first portion of the hydroxide salt of the metal M comprises Ca(OH)2. According to some embodiments, the first portion of the hydroxide salt of the metal M comprises Ca(OH)2 dissolved within the first separated liquid phase.

[0254] According to some embodiments, reacting the Ca(OH)2 with the CO2 in step (Va) entails carrying out one or more of the following chemical reaction:Ca(OH)2+ CO2CaCO3+ H2O;Ca(OH)2+ HCO3‘ CaCO3+ H2O + OH'; andCa(OH)2+ CO3-2CaCO3+ 2OH'.

[0255] According to some embodiments, reacting the Ca(OH)2 with the CO2 in step (Va) entails carrying out the following chemical reaction:Ca(OH)2+ CO2CaCO3+ H2O.

[0256] According to some embodiments, the first portion of the hydroxide salt of the metal M comprises Mg(OH)2. According to some embodiments, the first portion of the hydroxide salt of the metal M comprises Mg(OH)2 dissolved within the first separated liquid phase.

[0257] According to some embodiments, reacting the Mg(OH)2 with the CO2 in step (Va) entails carrying out one or more of the following chemical reaction:Mg(OH)2+ CO2MgCO3+ H2O;Mg(OH)2+ HCO3' MgCO3+ H2O + OH'; andMg(OH)2+ CO3'2MgCO3+ 2OH'.

[0258] According to some embodiments, reacting the Mg(OH)2with the CO2 in step (Va) entails carrying out the following chemical reaction:Mg(OH)2+ CO2MgCO3+ H2O.

[0259] According to some embodiments, the first portion of the hydroxide salt of the metal M comprises Mn(OH)2. According to some embodiments, the first portion of the hydroxide salt of the metal M comprises Mn(0H)2dissolved within the first separated liquid phase.

[0260] According to some embodiments, reacting the Mn(0H)2with the CO2 in step (Va) entails carrying out one or more of the following chemical reaction:Mn(0H)2+ CO2MnCO3+ H2O;Mn(0H)2+ HCO3' MnCO3+ H2O + OH'; andMn(0H)2+ CO3'2MnCO3+ 2OH'.

[0261] According to some embodiments, reacting the Mn(0H)2with the CO2 in step (Va) entails carrying out the following chemical reaction:Mn(0H)2+ CO2MnCO3+ H2O.

[0262] According to some embodiments, step (Va) comprises reacting the hydroxide salt of the metal M with CO2 at a predetermined pH. It is to be understood that monitoring the pH may be performed while adding the CO2 gas solution into the aqueous solution of the hydroxide salt. Thus, according to some embodiments, step (Va) comprises adding CO2 gas to the aqueous solution comprising the residual metal salt until the pH value of the aqueous solution reaches (e.g., is lowered to) a predetermined pH.

[0263] According to some embodiments, the addition of CO2 gas is performed using a CO2 diffuser.

[0264] According to some embodiments, the predetermined pH is in the range of 7 to 13, including each value and sub-range within the specified range.

[0265] According to some embodiments, step (Va) comprises reacting the hydroxide salt of M with excess CO2. According to some embodiments, step (Va) comprises reacting the M(0H)2 with excess CO2. According to some embodiments, step (Va) comprises reacting the Ca(OH)2 with excess CO2. According to some embodiments, step (Va) comprises reacting the Mg(OH)2 with excess CO2. According to some embodiments, step (Va) comprises reacting the Mn(0H)2 with excess CO2. It is to be understood that the term “excess” as used in the context of the ratio of reactants, refers to an amount which is more than the minimal amount required to stoichiometrically complete a full reaction. In the case of the reaction between Ca(OH)2 and CO2, the minimal amount of CO2 required to stoichiometrically complete a full reaction is 1 mol CO2 per 1 mol Ca(OH)2. Therefore, “excess CO2” in the case that M is divalent, refers to more than 1 mol CO2 per 1 mol M+2, and in the case of a trivalent M, excess refers to more than 1.5 mol CO2 per 1 mol residual M+3salt.

[0266] According to some embodiments, step (Va) comprises reacting the M(0H)2 with excess CO2 at a mol ratio of at least 1:1.01. According to some embodiments, step (Va) comprises reacting the M(0H)2 with excess CO2 at a mol ratio of at least 1:1.1. According to some embodiments, step (Va) comprises reacting the M(0H)2 with excess CO2 at a mol ratio of at least 1:1.2. According to some embodiments, step (Va) comprises reacting the M(0H)2 with excess CO2 at a mol ratio of at least 1:1.3. According to some embodiments, step (Va) comprises reacting the M(0H)2 with excess CO2 at a mol ratio of at least 1:1.4. According to some embodiments, step (Va) comprises reacting the M(0H)2 with excess CO2 at a mol ratio of at least 1:1.5. According to some embodiments, step (Va) comprises reacting the M(0H)2 with excess CO2 at a mol ratio of at least 1:2. According to some embodiments, step (Va) comprises reacting the M(0H)2 with excess CO2 at a mol ratio of at least 1:2.5. According to some embodiments, step (Va) comprises reacting the M(0H)2 with excess CO2 at a mol ratio of at least 1:5. According to some embodiments, step (Va) comprises reacting the M(0H)2 with excess CO2 at a mol ratio of at least 1: 10.

[0267] According to some embodiments, step (Va) comprises reacting the hydroxide salt of the metal M with excess CO2 at a mol ratio of at least 1: 1.01. According to some embodiments, step (Va) comprises reacting the hydroxide salt of the metal M with excess CO2 at a mol ratio of at least 1:1.1. According to some embodiments, step (Va) comprises reacting the hydroxide salt of the metal M with excess CO2 at a mol ratio of at least 1:1.2. According to some embodiments,step (Va) comprises reacting the hydroxide salt of the metal M with excess CO2 at a mol ratio of at least 1:1.3. According to some embodiments, step (Va) comprises reacting the hydroxide salt of the metal M with excess CO2 at a mol ratio of at least 1:1.4. According to some embodiments, step (Va) comprises reacting the hydroxide salt of the metal M with excess CO2 at a mol ratio of at least 1:1.5. According to some embodiments, step (Va) comprises reacting the hydroxide salt of the metal M with excess CO2 at a mol ratio of at least 1:2. According to some embodiments, step (Va) comprises reacting the hydroxide salt of the metal M with excess CO2 at a mol ratio of at least 1:2.5. According to some embodiments, step (Va) comprises reacting the hydroxide salt of the metal M with excess CO2 at a mol ratio of at least 1:5. According to some embodiments, step (Va) comprises reacting the hydroxide salt of the metal M with excess CO2 at a mol ratio of at least 1:10.

[0268] According to some embodiments, step (Va) comprises reacting the Ca(OH)2 with excess CO2 at a mol ratio of at least 1:1.01. According to some embodiments, step (Va) comprises reacting the Ca(OH)2 with excess CO2 at a mol ratio of at least 1:1.1. According to some embodiments, step (Va) comprises reacting the Ca(OH)2 with excess CO2 at a mol ratio of at least 1:1.2. According to some embodiments, step (Va) comprises reacting the Ca(OH)2 with excess CO2 at a mol ratio of at least 1:1.3. According to some embodiments, step (Va) comprises reacting the Ca(OH)2 with excess CO2 at a mol ratio of at least 1:1.4. According to some embodiments, step (Va) comprises reacting the Ca(OH)2 with excess CO2 at a mol ratio of at least 1:1.5. According to some embodiments, step (Va) comprises reacting the Ca(OH)2 with excess CO2 at a mol ratio of at least 1:2. According to some embodiments, step (Va) comprises reacting the Ca(OH)2 with excess CO2 at a mol ratio of at least 1:2.5. According to some embodiments, step (Va) comprises reacting the Ca(OH)2 with excess CO2 at a mol ratio of at least 1:5. According to some embodiments, step (Va) comprises reacting the Ca(OH)2with excess CO2 at a mol ratio of at least 1: 10.

[0269] According to some embodiments, step (Va) comprises reacting the Mg(OH)2 with excess CO2 at a mol ratio of at least 1:1.01. According to some embodiments, step (Va) comprises reacting the Mg(OH)2 with excess CO2 at a mol ratio of at least 1:1.1. According to some embodiments, step (Va) comprises reacting the Mg(OH)2 with excess CO2 at a mol ratio of at least 1:1.2. According to some embodiments, step (Va) comprises reacting the Mg(OH)2 with excess CO2 at a mol ratio of at least 1:1.3. According to some embodiments, step (Va) comprises reacting the Mg(OH)2 with excess CO2 at a mol ratio of at least 1:1.4. According to some embodiments, step (Va) comprises reacting the Mg(OH)2with excess CO2 at a mol ratioof at least 1:1.5. According to some embodiments, step (Va) comprises reacting the Mg(0H)2 with excess CO2 at a mol ratio of at least 1:2. According to some embodiments, step (Va) comprises reacting the Mg(0H)2 with excess CO2 at a mol ratio of at least 1:2.5. According to some embodiments, step (Va) comprises reacting the Mg(0H)2 with excess CO2 at a mol ratio of at least 1:5. According to some embodiments, step (Va) comprises reacting the Mg(0H)2 with excess CO2 at a mol ratio of at least 1: 10.

[0270] According to some embodiments, step (Va) comprises reacting the Mn(0H)2 with excess CO2 at a mol ratio of at least 1:1.01. According to some embodiments, step (Va) comprises reacting the Mn(0H)2 with excess CO2 at a mol ratio of at least 1:1.1. According to some embodiments, step (Va) comprises reacting the Mn(0H)2 with excess CO2 at a mol ratio of at least 1:1.2. According to some embodiments, step (Va) comprises reacting the Mn(0H)2 with excess CO2 at a mol ratio of at least 1:1.3. According to some embodiments, step (Va) comprises reacting the Mn(0H)2 with excess CO2 at a mol ratio of at least 1:1.4. According to some embodiments, step (Va) comprises reacting the Mn(OH)2with excess CO2 at a mol ratio of at least 1:1.5. According to some embodiments, step (Va) comprises reacting the Mn(0H)2 with excess CO2 at a mol ratio of at least 1:2. According to some embodiments, step (Va) comprises reacting the Mn(0H)2 with excess CO2 at a mol ratio of at least 1:2.5. According to some embodiments, step (Va) comprises reacting the Mn(0H)2 with excess CO2 at a mol ratio of at least 1:5. According to some embodiments, step (Va) comprises reacting the Mn(0H)2 with excess CO2 at a mol ratio of at least 1: 10.

[0271] According to some embodiments, the reaction of step (Va) entails forming phase separation. According to some embodiments, the reaction of step (Va) entails forming a second liquid phase and a second precipitate. According to some embodiments, the second precipitate is substantially insoluble in the liquid phase.

[0272] According to some embodiments, the second precipitate comprises a carbonate salt of the metal M. According to some embodiments, the carbonate salt of the metal M comprises MCO3. According to some embodiments, the carbonate salt of the metal M comprises CaCOs. According to some embodiments, the second precipitate comprises CaCOs. According to some embodiments, the carbonate salt of the metal M comprises MgCOs. According to some embodiments, the second precipitate comprises MgCOs. According to some embodiments, the carbonate salt of the metal M comprises MnCOs. According to some embodiments, the second precipitate comprises MnCOs.

[0273] According to some embodiments, the reaction of step (Va) comprises precipitation of a solid from the aqueous solution. According to some embodiments, the reaction of step (Va) entails forming a liquid phase and a precipitate.

[0274] Specifically, as carbonate salts of the metals of the present invention are nearly insoluble in water, they may precipitate as a solid. For example, CaCOs is nearly insoluble in water, having a solubility of 0.013 g / L in water. As the amount of calcium salts dissolved in the water may appear as a detrimental contaminant in the electrodialysis step (VI), it is an objective of the present invention to obtain a calcium depleted solution entering to step (VI). According to some embodiments, the objective is addressed in steps (Va) and (Vb), which separate the calcium salts from the liquid medium.

[0275] According to some embodiments, the precipitate formed in step (Va) comprises a solid. According to some embodiments, the carbonate salt of M is in a solid form. According to some embodiments, the MCO3 is in a solid form. According to some embodiments, the carbonate salt of Ca is in a solid form. According to some embodiments, the CaCOs is in a solid form. According to some embodiments, the carbonate salt of Mg is in a solid form. According to some embodiments, the MgCOs is in a solid form. According to some embodiments, the carbonate salt of Mn is in a solid form. According to some embodiments, the MnCOs is in a solid form. According to some embodiments, the precipitate formed in step (Va) comprises at least 50% MCO3 w / w. According to some embodiments, the precipitate formed in step (Va) comprises at least 60% MCO3 w / w. According to some embodiments, the precipitate formed in step (Va) comprises at least 70% MCO3 w / w. According to some embodiments, the precipitate formed in step (Va) comprises at least 80% MCO3 w / w. According to some embodiments, the precipitate formed in step (Va) comprises at least 90% MCO3 w / w. According to some embodiments, the precipitate formed in step (Va) comprises at least 95% MCO3 w / w. According to some embodiments, the precipitate formed in step (Va) comprises at least 98% MCO3 w / w. According to some embodiments, the precipitate formed in step (Va) comprises at least 50% CaCO3w / w. According to some embodiments, the precipitate formed in step (Va) comprises at least 60% CaCO, w / w. According to some embodiments, the precipitate formed in step (Va) comprises at least 70% CaCO3w / w. According to some embodiments, the precipitate formed in step (Va) comprises at least 80% CaCO3w / w. According to some embodiments, the precipitate formed in step (Va) comprises at least 90% CaCO3w / w. According to some embodiments, the precipitate formed in step (Va) comprises at least 95% CaCCV w / w. According to some embodiments, the precipitate formed in step (Va) comprises at least 98% CaCO3w / w. According to someembodiments, the precipitate formed in step (Va) comprises at least 50% MgCOs w / w. According to some embodiments, the precipitate formed in step (Va) comprises at least 60% MgCOs w / w. According to some embodiments, the precipitate formed in step (Va) comprises at least 70% MgCOs w / w. According to some embodiments, the precipitate formed in step (Va) comprises at least 80% MgCOs w / w. According to some embodiments, the precipitate formed in step (Va) comprises at least 90% MgCOs w / w. According to some embodiments, the precipitate formed in step (Va) comprises at least 95% MgCOs w / w. According to some embodiments, the precipitate formed in step (Va) comprises at least 98% MgCOs w / w. According to some embodiments, the precipitate formed in step (Va) comprises at least 50% MnCOs w / w. According to some embodiments, the precipitate formed in step (Va) comprises at least 60% MnCOs w / w. According to some embodiments, the precipitate formed in step (Va) comprises at least 70% MnCOs w / w. According to some embodiments, the precipitate formed in step (Va) comprises at least 80% MnCOs w / w. According to some embodiments, the precipitate formed in step (Va) comprises at least 90% MnCOs w / w. According to some embodiments, the precipitate formed in step (Va) comprises at least 95% MnCOs w / w. According to some embodiments, the precipitate formed in step (Va) comprises at least 98% MnCOs w / w.

[0276] According to some embodiments, the second liquid phase comprises the EX. According to some embodiments, the second liquid phase comprises NaCl. According to some embodiments, the second liquid phase comprises NaNCh.

[0277] Advantageously, as detailed herein, the step of the present method enables provision of a liquid composition to step (VI) that is substantially devoid of metals M, such as Ca+2. This may be imperative, as electrodialysis may be impaired by precipitation of metal salts, such as Ca+2salt(s).

[0278] According to some embodiments, the second liquid phase comprises no more than 500mg / L cations of the metal M dissolved therein. According to some embodiments, the second liquid phase comprises no more than 400mg / L cations of the metal M dissolved therein. According to some embodiments, the second liquid phase comprises no more than 300mg / L cations of the metal M dissolved therein. According to some embodiments, the second liquid phase comprises no more than 200mg / L cations of the metal M dissolved therein. According to some embodiments, the second liquid phase comprises no more than lOOmg / L cations of the metal M dissolved therein. According to some embodiments, the second liquid phase comprises no more than 50mg / L cations of the metal M dissolved therein. According to some embodiments,the second liquid phase comprises no more than 20mg / L cations of the metal M dissolved therein. According to some embodiments, the second liquid phase comprises no more than lOmg / L cations of the metal M dissolved therein. According to some embodiments, the second liquid phase comprises no more than 5mg / L cations of the metal M dissolved therein. According to some embodiments, the second liquid phase comprises no more than 2mg / L cations of the metal M dissolved therein. According to some embodiments, the second liquid phase comprises no more than Img / L cations of the metal M dissolved therein. According to some embodiments, the second liquid phase comprises no more than 0.5mg / L cations of the metal M dissolved therein. According to some embodiments, the second liquid phase comprises no more than O.lmg / L cations of the metal M dissolved therein.

[0279] According to some embodiments, the second liquid phase comprises no more than 500mg / L M+2dissolved therein. According to some embodiments, the second liquid phase comprises no more than 400mg / L M+2dissolved therein. According to some embodiments, the second liquid phase comprises no more than 300mg / L M+2dissolved therein. According to some embodiments, the second liquid phase comprises no more than 200mg / L M+2dissolved therein. According to some embodiments, the second liquid phase comprises no more than lOOmg / L M+2dissolved therein. According to some embodiments, the second liquid phase comprises no more than 50mg / L M+2dissolved therein. According to some embodiments, the second liquid phase comprises no more than 20mg / L M+2dissolved therein. According to some embodiments, the second liquid phase comprises no more than lOmg / L M+2dissolved therein. According to some embodiments, the second liquid phase comprises no more than 5mg / L M+2dissolved therein. According to some embodiments, the second liquid phase comprises no more than 2mg / L M+2dissolved therein. According to some embodiments, the second liquid phase comprises no more than Img / L M+2dissolved therein. According to some embodiments, the second liquid phase comprises no more than 0.5mg / L M+2dissolved therein. According to some embodiments, the second liquid phase comprises no more than O.lmg / L M+2dissolved therein.

[0280] According to some embodiments, the second liquid phase comprises no more than 500mg / L Ca+2dissolved therein. According to some embodiments, the second liquid phase comprises no more than 400mg / L Ca+2dissolved therein. According to some embodiments, the second liquid phase comprises no more than 300mg / L Ca+2dissolved therein. According to some embodiments, the second liquid phase comprises no more than 200mg / L Ca+2dissolved therein. According to some embodiments, the second liquid phase comprises no more than lOOmg / L Ca+2dissolved therein. According to some embodiments, the second liquid phase comprises nomore than 50mg / L Ca+2dissolved therein. According to some embodiments, the second liquid phase comprises no more than 20mg / L Ca+2dissolved therein. According to some embodiments, the second liquid phase comprises no more than lOmg / L Ca+2dissolved therein. According to some embodiments, the second liquid phase comprises no more than 5mg / L Ca+2dissolved therein. According to some embodiments, the second liquid phase comprises no more than 2mg / L Ca+2dissolved therein. According to some embodiments, the second liquid phase comprises no more than Img / L Ca+2dissolved therein. According to some embodiments, the second liquid phase comprises no more than 0.5mg / L Ca+2dissolved therein. According to some embodiments, the second liquid phase comprises no more than 0. Img / L Ca+2dissolved therein. According to some embodiments, the second liquid phase comprises no more than 500mg / L Mg+2dissolved therein. According to some embodiments, the second liquid phase comprises no more than 400mg / L Mg+2dissolved therein. According to some embodiments, the second liquid phase comprises no more than 300mg / L Mg+2dissolved therein. According to some embodiments, the second liquid phase comprises no more than 200mg / L Mg+2dissolved therein. According to some embodiments, the second liquid phase comprises no more than lOOmg / L Mg+2dissolved therein. According to some embodiments, the second liquid phase comprises no more than 50mg / L Mg+2dissolved therein. According to some embodiments, the second liquid phase comprises no more than 20mg / L Mg+2dissolved therein. According to some embodiments, the second liquid phase comprises no more than lOmg / L Mg+2dissolved therein. According to some embodiments, the second liquid phase comprises no more than 5mg / L Mg+2dissolved therein. According to some embodiments, the second liquid phase comprises no more than 2mg / L Mg+2dissolved therein. According to some embodiments, the second liquid phase comprises no more than 1mg / L Mg+2dissolved therein. According to some embodiments, the second liquid phase comprises no more than 0.5mg / L Mg+2dissolved therein. According to some embodiments, the second liquid phase comprises no more than O.lmg / L Mg+2dissolved therein. According to some embodiments, the second liquid phase comprises no more than 500mg / L Mn+2dissolved therein. According to some embodiments, the second liquid phase comprises no more than 400mg / L Mn+2dissolved therein. According to some embodiments, the second liquid phase comprises no more than 300mg / L Mn+2dissolved therein. According to some embodiments, the second liquid phase comprises no more than 200mg / L Mn+2dissolved therein. According to some embodiments, the second liquid phase comprises no more than lOOmg / L Mn+2dissolved therein. According to some embodiments, the second liquid phase comprises no more than 50mg / L Mn+2dissolved therein. According to some embodiments, the second liquid phase comprises no more than 20mg / L Mn+2dissolved therein. According to some embodiments,the second liquid phase comprises no more than lOmg / L Mn+2dissolved therein. According to some embodiments, the second liquid phase comprises no more than 5mg / L Mn+2dissolved therein. According to some embodiments, the second liquid phase comprises no more than 2mg / L Mn+2dissolved therein. According to some embodiments, the second liquid phase comprises no more than Img / L Mn+2dissolved therein. According to some embodiments, the second liquid phase comprises no more than 0.5mg / L Mn+2dissolved therein. According to some embodiments, the second liquid phase comprises no more than O.lmg / L Mn+2dissolved therein.

[0281] According to some embodiments, the second liquid phase formed in step (Va) has pH in the range of 4 to 12, including each value and sub-range within the specified range.

[0282] According to some embodiments, the second liquid phase comprises 0.1M to 5M EX dissolved therein, including each value and sub-range within the specified range.

[0283] According to some embodiments, the first liquid phase formed in step (Va) comprises 0.5gr / L to 600gr / L EX dissolved therein. According to some embodiments, the first liquid phase formed in step (Va) comprises 0.5gr / L to 600gr / L NaX dissolved therein dissolved therein. According to some embodiments, the first liquid phase formed in step (Va) comprises 0.5gr / L to 320gr / L NaCl dissolved therein dissolved therein. According to some embodiments, the first liquid phase formed in step (Va) comprises 0.8gr / L to 600gr / L NaNOs dissolved therein dissolved therein.

[0284] According to some embodiments, the reacting of step (Va) is carried out at a temperature of no more than 200°C. According to some embodiments, the reacting of step (Va) is carried out at a temperature of no more than 150°C. According to some embodiments, the reacting of step (Va) is carried out at a temperature of no more than 120°C. According to some embodiments, the reacting of step (Va) is carried out at a temperature of no more than 100°C. According to some embodiments, the reacting of step (Va) is carried out at a temperature of no more than 90°C. According to some embodiments, the reacting of step (Va) is carried out at a temperature of no more than 80°C. According to some embodiments, the reacting of step (Va) is carried out at a temperature of at least 0°C. According to some embodiments, the reacting of step (Va) is carried out at a temperature of at least 5°C. According to some embodiments, the reacting of step (Va) is carried out at a temperature in the range of 5°C to 80°C, including each value and sub-range within the specified range. According to some embodiments, reacting of step (Va) is carried out at a temperature in the range of 15°C to 60°C, including each value and sub-range within the specified range. According to some embodiments, the reacting of step (Va)is carried out at room temperature or less. According to some embodiments, the reaction of step (Va) is carried out at a temperature of about 40°C.

[0285] According to some embodiments, the reaction of step (Va) is carried out in a vessel comprising polymeric walls. According to some embodiments, the reaction of step (Va) is expedited by the introduction of nucleation seeds of the metal carbonate. According to some embodiment, the reaction of step (Va) is carried out in a fluidized bed reactor.

[0286] Specific reference is now made to step (Vb) of the present process. According to some embodiments, the present process comprises step (Vb) of separating the second precipitate from the second liquid phase. According contacting to some embodiments, step (IV) is also represented as step 1060 in Figure 1A, Figure 1B and Figure 1C.

[0287] Also in Figures 1A-1C, the separated second precipitate is represented as 1062 and the separated second liquid phase is represented as 1064.

[0288] According to some embodiments, separating the second precipitate from the second liquid phase entails separating the carbonate salt of the metal M from the EX. According to some embodiments, separating the second precipitate from the second liquid phase entails separating the MCO3 from the EX. According to some embodiments, separating the second precipitate from the second liquid phase entails separating the CaCOs from the EX. According to some embodiments, separating the second precipitate from the second liquid phase entails separating the MgCOs from the EX. According to some embodiments, separating the second precipitate from the second liquid phase entails separating the MnCOs from the EX.

[0289] According to some embodiments, separating the second precipitate from the second liquid phase entails separating the carbonate salt of the metal M from the NaCl or NaNCE. According to some embodiments, separating the second precipitate from the second liquid phase entails separating the MCO3 from the NaCl or NaNO,. According to some embodiments, separating the second precipitate from the second liquid phase entails separating the CaCCE from the NaCl or NaNO?. According to some embodiments, separating the second precipitate from the second liquid phase entails separating the MgCCE from the NaCl or NaNO,. According to some embodiments, separating the second precipitate from the second liquid phase entails separating the MnCO, from the NaCl or NaN,.

[0290] According to some embodiments, step (Vb) comprises isolating the carbonate salt of the metal M. According to some embodiments, step (Vb) comprises isolating the MCO3. According to some embodiments, step (Vb) comprises isolating the CaCO,. According to someembodiments, step (Vb) comprises isolating the MgCOs. According to some embodiments, step (Vb) comprises isolating the MnCOs.

[0291] Separation techniques of solids from liquids are well known in the art. According to some embodiments, the separation includes filtration. According to some embodiments, separating the second precipitate comprising the carbonate salt of the metal M from the second liquid phase in step (Vb) comprises filtering the second precipitate from the second liquid phase. According to some embodiments, separating the second precipitate comprising the CaCOs from the second liquid phase in step (Vb) comprises filtering the second precipitate from the second liquid phase. According to some embodiments, separating the second precipitate comprising the MgCOs from the second liquid phase in step (Vb) comprises filtering the second precipitate from the second liquid phase. According to some embodiments, separating the second precipitate comprising the MnCOs from the second liquid phase in step (Vb) comprises filtering the second precipitate from the second liquid phase. According to some embodiments, separating the second precipitate comprising the MCO3 from the second liquid phase in step (Vb) comprises filtering the second precipitate from the second liquid phase.

[0292] According to some embodiments, the filtering is performed using a filter, which has a cutoff of at least 0.2 micron. According to some embodiments, the cutoff is at least 0.5 micron. According to some embodiments, the cutoff is at least 1 micron. According to some embodiments, the cutoff is no more than 500 micron. According to some embodiments, the cutoff is no more than 250 micron. According to some embodiments, the cutoff is no more than 100 micron. According to some embodiments, the cutoff is no more than 50 micron. According to some embodiments, the cutoff is no more than 10 micron. According to some embodiments, the cutoff is in the range of 0.2 micron to 500 micron, including each value and sub-range within the specified range. According to some embodiments, the cutoff is in the range of 1 micron to 100 micron, including each value and sub-range within the specified range. According to some embodiments, the cutoff is in the range of 5 micron to 25 micron, including each value and subrange within the specified range.

[0293] According to some embodiments, the second separated liquid phase is an aqueous mixture. According to some embodiments, the second separated liquid phase is an aqueous solution or suspension. Each possibility represents a separate embodiment of the invention. According to some embodiments, the second separated liquid phase is an aqueous solution.

[0294] According to some embodiments, the second separated liquid phase comprises water and the EX dissolved therein. According to some embodiments, the second separated liquid phase comprises water and the NaCl or NaNO3 dissolved therein.

[0295] According to some embodiments, the second precipitate comprises the carbonate salt of M as a solid. According to some embodiments, the second precipitate comprises the MCO3 as a solid. According to some embodiments, the second precipitate comprises the CaCO3 as a solid. According to some embodiments, the second precipitate comprises the MgCO3 as a solid. According to some embodiments, the second precipitate comprises the MnCO3 as a solid.

[0296] According to some embodiments, the second separated precipitate comprises the carbonate salt of M as a solid and liquid water. According to some embodiments, the second separated precipitate comprises the MCO3 as a solid and liquid water. According to some embodiments, the second separated precipitate comprises the CaCO3as a solid and liquid water. According to some embodiments, the second separated precipitate comprises the MgCO3 as a solid and liquid water. According to some embodiments, the second separated precipitate comprises the MnCO3 as a solid and liquid water. According to some embodiments, a water content within the second precipitate is in the range of 10% to 70% w / w, including each value and sub-range within the specified range. According to some embodiments, the water within the precipitate has pH in the range of 10 to 14, including each value and sub-range within the specified range. According to some embodiments, the water within the precipitate has pH in the range of 11 to 13. According to some embodiments, the water within the precipitate has pH in the range of 7 to 13.

[0297] According to some embodiments, the method further comprises performing steps (I) to (VI), for at least one consecutive cycle, wherein the carbonate salt of the metal M separated in step (Vb) is provided to consecutive step (II). According to some embodiments, the method further comprises performing steps (I) to (VI), for at least one consecutive cycle, and further comprises an acidification of the carbonate salt of the metal M recovered in step (Vb), wherein the acidification is performed according to the definitions of step (II). According to some embodiments, the acidification of the carbonate salt of the metal M recovered in step (Vb) may be carried out in a dedicated dissolution compartment, which is separate from a reactor in which step (II) is performed on the carbonate salt provided in step (I). According to some embodiments, the method further comprises performing steps (I) to (VI), for at least one consecutive cycle, wherein the MCO3 separated in step (Vb) is provided to consecutive step (II). According to some embodiments, the acidification of the MCO3 recovered in step (Vb) may be carried out in adedicated dissolution compartment that performs step (II), separate from the main step-(II) reactor. According to some embodiments, the method further comprises performing steps (I) to (VI), for at least one consecutive cycle, wherein the CaCO3separated in step (Vb) is provided to consecutive step (II). According to some embodiments, the acidification of the CaCO3 recovered in step (Vb) may be carried out in a dedicated dissolution compartment that performs step (II), separate from the main step-(II) reactor. According to some embodiments, the method further comprises performing steps (I) to (VI), for at least one consecutive cycle, and further comprises an acidification of the CaCO3 recovered in step (Vb), wherein the acidification is performed according to the definitions of step (II). According to some embodiments, the acidification of the CaCO3 recovered in step (Vb) may be carried out in a dedicated dissolution compartment, which is separate from a reactor in which step (II) is performed on the carbonate salt provided in step (I). According to some embodiments, the method further comprises performing steps (I) to (VI), for at least one consecutive cycle, wherein the MgCO3 separated in step (Vb) is provided to consecutive step (II). According to some embodiments, the acidification of the MgCO3 recovered in step (Vb) may be carried out in a dedicated dissolution compartment that performs step (II), separate from the main step-(II) reactor. According to some embodiments, the method further comprises performing steps (I) to (VI), for at least one consecutive cycle, and further comprises an acidification of the MgCO3 recovered in step (Vb), wherein the acidification is performed according to the definitions of step (II). According to some embodiments, the acidification of the MgCO3 recovered in step (Vb) may be carried out in a dedicated dissolution compartment, which is separate from a reactor in which step (II) is performed on the carbonate salt provided in step (I). According to some embodiments, the method further comprises performing steps (I) to (VI), for at least one consecutive cycle, wherein the MnCO3 separated in step (Vb) is provided to consecutive step (II). According to some embodiments, the acidification of the MnCO3 recovered in step (Vb) may be carried out in a dedicated dissolution compartment that performs step (II), separate from the main step-(II) reactor. According to some embodiments, the method further comprises performing steps (I) to (VI), for at least one consecutive cycle, and further comprises an acidification of the MnCO3 recovered in step (Vb), wherein the acidification is performed according to the definitions of step (II). According to some embodiments, the acidification of the MnCO3 recovered in step (Vb) may be carried out in a dedicated dissolution compartment, which is separate from a reactor in which step (II) is performed on the carbonate salt provided in step (I). The recycled carbonate stream may thus undergo step (II) in a physically separate compartment while the fresh carbonate feed undergoes step (II) in the main reactor. According to some embodiments, the residual metalsalt that includes M and at least one X' anion formed by performing step (II) in the dedicated dissolution compartment may be combined with the residual metal salt that includes M and at least one X' anion formed in the main step-(II) reactor, or alternatively may be provided separately to step (III). Each possibility represents a separate embodiment of the invention. According to some embodiments, the liquid composition (e.g., aqueous solution) formed by performing step (II) in the dedicated dissolution compartment may be combined with the liquid composition (e.g., aqueous solution) formed in the main step-(II) reactor, or alternatively may be provided separately to step (III). Each possibility represents a separate embodiment of the invention.

[0298] It is to be understood that that phrase “wherein the carbonate salt of the metal M separated in step (Vb) is provided to step (II)” is intended to cover both the option wherein the carbonate salt of the metal M separated in step (Vb) is provided to main step-(II) reactor; and the option wherein the carbonate salt of the metal M separated in step (Vb) is provided to the separate recycling-dedicated step-(II) reactor.

[0299] According to some embodiments, the second liquid phase has similar properties upon the separation of step (Vb) as upon its formation in step (Va). Therefore, embodiments directed to the properties of the liquid phase or aqueous solution formed in step (Va) may be applied to the separated liquid phase or aqueous solution obtained in step (Vb). Such properties include, but not limited to, the concentrations of EX, ECI, ENO3, NaX, NaCl, NaNO3, any salt of M and the pH.

[0300] Specific reference is now made to step (Vc) of the present process. According to some embodiments, the present process comprises step (Vc) of contacting the separated second liquid phase with an acid.

[0301] According to some embodiments, step (Vc) of the present method is optional, and it is directed to removal of DICs from the separated second liquid phase that is formed in step (Vb). Thus, both the product of step (Vb) and the product of the (Vc) are individually referred herein as “separated second liquid phase”. Therefore, it is to be understood that when the present disclosure refers to “separated second liquid phase” it may refer to the product of step (Vb) (e.g., in the case that step (Vc) is not performed) and / or to the product of the (Vc) (e.g., when performing step (Vc)). Such references may be relevant, e.g., when referring to the composition which is provided to step (VI), which, unless specified otherwise refers broadly to the product of step (Vb) and / or to the product of the (Vc).

[0302] According to some embodiments, the separated second liquid phase is provided from step (Vb) as an aqueous mixture. According to some embodiments, the separated second liquid phase is provided from step (Vb) as an aqueous solution or suspension. Each possibility represents a separate embodiment of the invention. According to some embodiments, the separated second liquid phase is provided from step (Vb) as an aqueous solution.

[0303] According to some embodiments, the separated second liquid phase comprises the EX dissolved therein. According to some embodiments, the separated second liquid phase comprises the NaCl or NaNO3 dissolved therein.

[0304] According to some embodiments, the separated second liquid phase comprises residual dissolved inorganic carbon species. According to some embodiments, the separated second liquid phase is provided from step (Vb) comprising residual dissolved inorganic carbon species. According to some embodiments, the separated second liquid phase comprises residual dissolved inorganic carbon species dissolved therein. According to some embodiments, the separated second liquid phase is provided from step (Vb) comprising residual dissolved inorganic carbon species dissolved therein.

[0305] Residual dissolved inorganic carbon species may include any carbonate or bicarbonate species, according to some embodiments.

[0306] According to some embodiments, the acid of step (Vc) has the formula HX. According to some embodiments, X is selected from the group consisting of: halide, NO3⁻, HSO4⁻, H2PO3⁻, HCO3⁻, CH3COO⁻ and HCOO⁻. Each possibility represents a separate embodiment of the invention. According to some embodiments, X is selected from the group consisting of: halide, NO3⁻, HSO4⁻, H2PO3⁻ and HCO3⁻. According to some embodiments, X is a halide. According to some embodiments, X is Cl' or Br'. According to some embodiments, X is Cl'. According to some embodiments, X is a halide or nitrate. According to some embodiments, X is Cl-or NO3-. According to some embodiments, X is NOs'.

[0307] According to some embodiments, the acid of step (Vc) is selected from the group consisting of: HF, HC1, HBr, HI, HNO3, H2SO4, H3PO3, H2CO3, CH3COOH and HCOH. Each possibility represents a separate embodiment of the invention. According to some embodiments, the acid is selected from the group consisting of: HF, HC1, HBr, HI, HNO3, H2SO4, H3PO3 and H2CO3. According to some embodiments, the acid is a hydrohalic acid. According to some embodiments, the acid is HC1 or HBr. According to some embodiments, the acid is HC1. According to some embodiments, the acid is hydrochloric acid. According to someembodiments, the acid is a hydrohalic acid or nitric acid. According to some embodiments, the acid is HC1 or HNO3. According to some embodiments, the acid is HNO3. According to some embodiments, the acid is nitric acid.

[0308] According to some embodiments, the acid is provided as an aqueous mixture. According to some embodiments, the acid is provided as an aqueous solution. According to some embodiments, the acid is an aqueous solution of hydrohalic acid or nitric acid. According to some embodiments, the acid is an aqueous solution of hydrochloric acid or nitric acid. According to some embodiments, the acid is an aqueous solution of hydrohalic acid. According to some embodiments, the acid is an aqueous solution of hydrochloric acid. According to some embodiments, the acid is an aqueous solution of nitric acid.

[0309] According to some embodiments, the acid has a concentration of at least 0.01M. According to some embodiments, the acid has a concentration of no more than 5M. According to some embodiments, the acid has a concentration in the range of 0.01M to 5M, including each value and sub-range within the specified range.

[0310] According to some embodiments, the hydrochloric acid has a HC1 concentration of at least 0.01M. According to some embodiments, the hydrochloric acid has a HC1 concentration of no more than 5M. According to some embodiments, the hydrochloric acid has a HC1 concentration in the range of 0.01M to 5M, including each value and sub-range within the specified range.

[0311] According to some embodiments, the nitric acid has a HNO3 concentration of at least 0.01M. According to some embodiments, the nitric acid has a HNO3 concentration of no more than 5M. According to some embodiments, the nitric acid has a HNO3 concentration in the range of 0.01M to 5M, including each value and sub-range within the specified range.

[0312] According to some embodiments, the process comprises performing step (VI), wherein step (VI) entails forming an acid, and wherein a subsequent step (Vc), which follows step (VI) comprises reacting the residual dissolved inorganic carbon species with the acid formed in step (VI).

[0313] According to some embodiments, step (Vc) comprises reacting the residual dissolved inorganic carbon species with the acid, thereby carrying out at least one of the following chemical reactions:CO3’2+ 2HX 2X- + C02+ H2O,andHCO3⁻ + HX → X⁻ + CO2 + H2O. Each possibility represents a separate embodiment of the invention.

[0314] According to some embodiments, step (Vc) comprises reacting the residual dissolved inorganic carbon species with the acid, thereby carrying out at least the following chemical reaction:CO3’2+ 2HX 2X’ + CO2+ H2O.

[0315] According to some embodiments, step (Vc) comprises reacting the residual dissolved inorganic carbon species with the acid, thereby carrying out at least the following chemical reaction:HCO3⁻ + HX → X⁻ + CO2 + H2O.

[0316] According to some embodiments, step (Vc) comprises reacting the residual dissolved inorganic carbon species with the acid, thereby carrying out at least one of the following chemical reactions:CO3’2+ 2HC1 2C1- + CO2+ H2O,CO3²⁻ + 2HNO3 → 2NO3⁻ + CO2 + H2O,HCO3- + HC1 Cl’ + CO2+ H2O,andHCO3⁻ + HNO3 → NO3⁻ + CO2 + H2O. Each possibility represents a separate embodiment of the invention.

[0317] It is to be appreciated that since CO2 is somewhat soluble in water (e.g., as carbonic acid, H2CO3), a portion thereof may still exist in the solution, as a DIC, according to some embodiments, after the contacting of the separated second liquid phase with the acid. Removal of the CO2 / H2CO3from the separated second liquid phase may be promoted via aeration, according to some embodiments. Removal of the CO2 / H2CO3from the separated second liquid phase may be promoted via vacuum stripping, according to some embodiments.

[0318] As used herein, the term "aeration" refers to the process of introducing a gas into a liquid or exposing a liquid to a gas to facilitate the transfer of gases between the liquid phase and the surrounding gas phase. Aeration may be employed for various purposes, including but not limited to degassing, which involves the removal of dissolved gases from a liquid. In particular, aeration includes the removal of dissolved carbon dioxide (CO2) from an aqueous solution, wherein the solution is exposed to a gas, such as air, nitrogen, or other gases, to promote the release and transfer of CO2 from the liquid phase into the gas phase. This can occur through various techniques, including physical agitation, sparging, bubbling, or other methods that enhance gas-liquid exchange. The term "aeration" is not limited to a specific type of gas and encompasses the introduction of any suitable gas, such as air or nitrogen, to achieve gas-liquid interaction and facilitate the removal of dissolved gases or the promotion of other desired processes. Unless otherwise specified, the term "aeration" encompasses both natural and forced processes for introducing gases into liquids to enhance gas transfer, stripping, or displacement of dissolved gases from the liquid medium.

[0319] As used herein, the term “vacuum stripping” refers to the removal of dissolved gases from a liquid composition by reducing the ambient pressure so as to promote desorption and release of those gases, including dissolved CO2. Vacuum stripping may be performed using any suitable pressure-reduction technique and does not impose any limitation on the type of vessel or equipment employed.

[0320] According to some embodiments, step (Vc) further comprises aerating the separated second liquid phase. According to some embodiments, the aeration entails reducing a CO2 concentration within the separated second liquid phase.

[0321] According to some embodiments, step (Vc) is performed at a pH in the range of 1 to 7, including each value and sub-range within the specified range.

[0322] According to some embodiments, step (Vc) is performed at a temperature in the range of 0°C to 150°C, including each value and sub-range within the specified range.

[0323] According to some embodiments, reacting the residual dissolved inorganic carbon species with the acid entails forming carbon dioxide. According to some embodiments, the CO2 formed in step (Vc) is in a gas form. According to some embodiments, step (Vc) comprises isolating and storing at least a portion of the CO2 gas.

[0324] The term “portion” as used herein refers to any part or segment of an amount or quantity of a material, which may include the entirety or just a subset of the total. This term isinclusive and can pertain to any proportion, fraction, or component, such as a chemical composition or mixture. For example, when referring to a chemical composition, a portion could include some or all of the chemicals present in the mixture, allowing for flexible interpretations within the scope of the disclosure.

[0325] According to some embodiments, the method further comprises performing steps (I) to (VI), for at least one consecutive cycle, wherein the CO2 formed in step (Vc) is provided to consecutive step (Va).

[0326] According to some embodiments, step (Vc) comprises removing the residual dissolved inorganic carbon species from the separated second liquid phase. According to some embodiments, step (Vc) comprises removing the residual dissolved inorganic carbon species from the separated second liquid phase as CO2 gas.

[0327] According to some embodiments, the separated second liquid phase comprises no more than 500mg / L dissolved inorganic carbon species dissolved therein. According to some embodiments, the separated second liquid phase comprises no more than 400mg / L dissolved inorganic carbon species dissolved therein. According to some embodiments, the separated second liquid phase comprises no more than 300mg / L dissolved inorganic carbon species dissolved therein. According to some embodiments, the separated second liquid phase comprises no more than 200mg / L dissolved inorganic carbon species dissolved therein. According to some embodiments, the separated second liquid phase comprises no more than 100mg / L dissolved inorganic carbon species dissolved therein. According to some embodiments, the separated second liquid phase comprises no more than 50mg / L dissolved inorganic carbon species dissolved therein. According to some embodiments, the separated second liquid phase comprises no more than 20mg / L dissolved inorganic carbon species dissolved therein. According to some embodiments, the separated second liquid phase comprises no more than 10mg / L dissolved inorganic carbon species dissolved therein. According to some embodiments, the separated second liquid phase comprises no more than 5mg / L dissolved inorganic carbon species dissolved therein. According to some embodiments, the separated second liquid phase comprises no more than 2mg / L dissolved inorganic carbon species dissolved therein. According to some embodiments, the separated second liquid phase comprises no more than 1mg / L dissolved inorganic carbon species dissolved therein. According to some embodiments, the separated second liquid phase comprises no more than 0.5mg / L dissolved inorganic carbon species dissolved therein. According to some embodiments, the separated second liquid phase comprises no more than 0.1mg / L dissolved inorganic carbon species dissolved therein.

[0328] As used herein, the term “metal recovery efficiency” refers to the percentage of a metal M that is recovered in one or more isolated solid phases during the process, relative to the total amount of metal M originally present in the provided feedstock. The metal recovery efficiency may be determined on a mass basis, by comparing the amount of metal M measured in isolated solids with the initial amount of metal M in the feedstock, or on a solution-basis, by comparing the amount of metal in the carbonate salt of the metal M provided in step (I) to the outlet concentrations of the metal M across the relevant precipitation and separation stages (e.g., steps (III), (IV), (Va) and / or (Vc).

[0329] According to some embodiments, “Ca efficiency” or “calcium recovery efficiency” refers to the percentage of calcium that is precipitated and isolated as one or more solid calcium-containing phases, including but not limited to Ca(OH)2 and CaCOs, relative to the total calcium present in the feedstock. According to some embodiments, “Mg efficiency” or “magnesium recovery efficiency” refers to the percentage of magnesium that is precipitated and isolated as one or more solid magnesium-containing phases, including but not limited to Mg(OH)2 and MgCOs, relative to the total magnesium present in the feedstock. According to some embodiments, “Mn efficiency” or “manganese recovery efficiency” refers to the percentage of manganese that is precipitated and isolated as one or more solid manganese-containing phases, including but not limited to Mn(OH)2 and MnCO3, relative to the total manganese present in the feedstock.

[0330] According to some embodiments, the process of the present invention results in a metal recovery efficiency of at least 50%. According to some embodiments, the metal recovery efficiency is at least 60%. According to some embodiments, the metal recovery efficiency is at least 70%. According to some embodiments, the metal recovery efficiency is at least 80%. According to some embodiments, the metal recovery efficiency is at least 85%. According to some embodiments, the metal recovery efficiency is at least 90%. According to some embodiments, the metal recovery efficiency is at least 95%. According to some embodiments, the metal recovery efficiency is at least 98%. According to some embodiments, the metal recovery efficiency is at least 99%. According to some embodiments, the process of the present invention results in a Ca recovery efficiency of at least 50%. According to some embodiments, the Ca recovery efficiency is at least 60%. According to some embodiments, the Ca recovery efficiency is at least 70%. According to some embodiments, the Ca recovery efficiency is at least 80%. According to some embodiments, the Ca recovery efficiency is at least 85%. According to some embodiments, the Ca recovery efficiency is at least 90%. According to some embodiments,the Ca recovery efficiency is at least 95%. According to some embodiments, the Ca recovery efficiency is at least 98%. According to some embodiments, the Ca recovery efficiency is at least 99%. According to some embodiments, the process of the present invention results in a Mg recovery efficiency of at least 50%. According to some embodiments, the Mg recovery efficiency is at least 60%. According to some embodiments, the Mg recovery efficiency is at least 70%. According to some embodiments, the Mg recovery efficiency is at least 80%. According to some embodiments, the Mg recovery efficiency is at least 85%. According to some embodiments, the Mg recovery efficiency is at least 90%. According to some embodiments, the Mg recovery efficiency is at least 95%. According to some embodiments, the Mg recovery efficiency is at least 98%. According to some embodiments, the Mg recovery efficiency is at least 99%. According to some embodiments, the process of the present invention results in a Mn recovery efficiency of at least 50%. According to some embodiments, the Mn recovery efficiency is at least 60%. According to some embodiments, the Mn recovery efficiency is at least 70%. According to some embodiments, the Mn recovery efficiency is at least 80%. According to some embodiments, the Mn recovery efficiency is at least 85%. According to some embodiments, the Mn recovery efficiency is at least 90%. According to some embodiments, the Mn recovery efficiency is at least 95%. According to some embodiments, the Mn recovery efficiency is at least 98%. According to some embodiments, the Mn recovery efficiency is at least 99%.

[0331] According to some embodiments, the reaction of step (V) is carried out in a vessel comprising polymeric walls.

[0332] Specific reference is now made to step (VI) of the present process. According to some embodiments, the present process comprises step (VI) of subjecting the EX to electrodialysis or electrolysis. According to some embodiments, step (VI) is also represented as step 1070 in Figure 1A, Figure 1B and Figure 1C.

[0333] According to some embodiments, subjecting the EX of step (V) to electrodialysis or electrolysis performed in the presence of water. According to some embodiments, step (VI) comprises subjecting the liquid composition comprising the EX dissolved therein of step (V) to electrodialysis.

[0334] According to some embodiments, the NaCl electrodialysis of step (VI) further entails forming deionized aqueous mixture. According to some embodiments, the NaCl electrodialysis of step (VI) further entails forming an aqueous mixture of lower salinity than the salinity of the aqueous mixture provided to step (VI). According to some embodiments, the salinity of theaqueous mixture is restored by using pressure filtration to form a retentate with the same salinity as the NaCl solution provided to step (VI).

[0335] According to some embodiments, the NaNO₃ electrodialysis of step (VI) further entails forming deionized aqueous mixture. According to some embodiments, the NaNO₃ electrodialysis of step (VI) further entails forming an aqueous mixture of lower salinity than the salinity of the aqueous mixture provided to step (VI). According to some embodiments, the salinity of the aqueous mixture is restored by using pressure filtration to form a retentate with the same salinity as the NaNO₃ solution provided to step (VI).

[0336] According to some embodiments, at least a portion of a deionized aqueous stream obtained upon performing step (VI) is subjected to pressure-driven membrane filtration. According to some embodiments, the pressure-driven membrane filtration comprises reverse osmosis or nanofiltration. According to some embodiments, upon applying the pressure-driven membrane filtration, a retentate and a permeate are obtained. According to some embodiments, the permeate comprises reduced salinity.

[0337] According to some embodiments, the retentate comprises an elevated concentration of EX. According to some embodiments, the retentate comprises a salinity of EX which is in the range of ±25% compared to the salinity of the separated second liquid phase. According to some embodiments, the retentate obtained by the pressure-driven membrane filtration exhibits a salinity suitable for electrodialysis or electrolysis. According to some embodiments, the retentate obtained by the pressure-driven membrane filtration exhibits an EX concentration suitable for electrodialysis or electrolysis. According to some embodiments, a salinity suitable for electrodialysis corresponds to an EX concentration in the range of 0.01 M to 5 M, including each value and sub-range within the specified range. According to some embodiments, the retentate may be provided as at least part of the EX feed in a subsequent performance of step (VI). According to some embodiments, a subsequent performance of step (VI) comprises subjecting the retentate obtained by the pressure-driven membrane filtration to electrolysis or electrodialysis thereby regenerating the base of step (III), EOH, and the acid of step (II), HX.

[0338] Advantageously, as detailed herein, the steps of the present method enable provision of a liquid composition to step (VI) that is substantially devoid of metal cations of M, such as Ca+2. This may be imperative, as electrodialysis may be impaired by precipitation of Ca+2salt(s).

[0339] Also advantageously, as detailed herein, the steps of the present method enable provision of a liquid composition to step (VI) that is substantially devoid of dissolved inorganiccarbon (DIC) species, such as CO3-2. This may be imperative, as electrodialysis may be impaired by such DICs.

[0340] According to some embodiments, the liquid composition provided to step (VI) comprises no more than 500mg / L metal cations of M dissolved therein. According to some embodiments, the liquid composition comprises no more than 400mg / L metal cations of M dissolved therein. According to some embodiments, the liquid composition comprises no more than 300mg / L metal cations of M dissolved therein. According to some embodiments, the liquid composition comprises no more than 200mg / L metal cations of M dissolved therein. According to some embodiments, the liquid composition comprises no more than 100mg / L metal cations of M dissolved therein. According to some embodiments, the liquid composition comprises no more than 50mg / L metal cations of M dissolved therein. According to some embodiments, the liquid composition comprises no more than 20mg / L metal cations of M dissolved therein. According to some embodiments, the liquid composition comprises no more than 10mg / L metal cations of M dissolved therein. According to some embodiments, the liquid composition comprises no more than 5mg / L metal cations of M dissolved therein. According to some embodiments, the liquid composition comprises no more than 2mg / L metal cations of M dissolved therein. According to some embodiments, the liquid composition comprises no more than 1mg / L metal cations of M dissolved therein. According to some embodiments, the liquid composition comprises no more than 0.5mg / L metal cations of M dissolved therein. According to some embodiments, the liquid composition comprises no more than 0.1mg / L metal cations of M dissolved therein.

[0341] According to some embodiments, the liquid composition provided to step (VI) comprises no more than 500mg / L M+2dissolved therein. According to some embodiments, the liquid composition comprises no more than 400mg / L M+2dissolved therein. According to some embodiments, the liquid composition comprises no more than 300mg / L M+2dissolved therein. According to some embodiments, the liquid composition comprises no more than 200mg / L M+2dissolved therein. According to some embodiments, the liquid composition comprises no more than 100mg / L M+2dissolved therein. According to some embodiments, the liquid composition comprises no more than 50mg / L M+2dissolved therein. According to some embodiments, the liquid composition comprises no more than 20mg / L M+2dissolved therein. According to some embodiments, the liquid composition comprises no more than 10mg / L M+2dissolved therein. According to some embodiments, the liquid composition comprises no more than 5mg / L M+2dissolved therein. According to some embodiments, the liquid composition comprises no morethan 2mg / L M+2dissolved therein. According to some embodiments, the liquid composition comprises no more than 1mg / L M+2dissolved therein. According to some embodiments, the liquid composition comprises no more than 0.5mg / L M+2dissolved therein. According to some embodiments, the liquid composition comprises no more than 0.1mg / L M+2dissolved therein.

[0342] According to some embodiments, the liquid composition provided to step (VI) comprises no more than 500mg / L Ca+2dissolved therein. According to some embodiments, the liquid composition comprises no more than 400mg / L Ca+2dissolved therein. According to some embodiments, the liquid composition comprises no more than 300mg / L Ca+2dissolved therein. According to some embodiments, the liquid composition comprises no more than 200mg / L Ca+2dissolved therein. According to some embodiments, the liquid composition comprises no more than 100mg / L Ca+2dissolved therein. According to some embodiments, the liquid composition comprises no more than 50mg / L Ca+2dissolved therein. According to some embodiments, the liquid composition comprises no more than 20mg / L Ca+2dissolved therein. According to some embodiments, the liquid composition comprises no more than 10mg / L Ca+2dissolved therein. According to some embodiments, the liquid composition comprises no more than 5mg / L Ca+2dissolved therein. According to some embodiments, the liquid composition comprises no more than 2mg / L Ca+2dissolved therein. According to some embodiments, the liquid composition comprises no more than 1mg / L Ca+2dissolved therein. According to some embodiments, the liquid composition comprises no more than 0.5mg / L Ca+2dissolved therein. According to some embodiments, the liquid composition comprises no more than 0.1mg / L Ca+2dissolved therein. According to some embodiments, the liquid composition provided to step (VI) comprises no more than 500mg / L Mg+2dissolved therein. According to some embodiments, the liquid composition comprises no more than 400mg / L Mg+2dissolved therein. According to some embodiments, the liquid composition comprises no more than 300mg / L Mg+2dissolved therein. According to some embodiments, the liquid composition comprises no more than 200mg / L Mg+2dissolved therein. According to some embodiments, the liquid composition comprises no more than 100mg / L Mg+2dissolved therein. According to some embodiments, the liquid composition comprises no more than 50mg / L Mg+2dissolved therein. According to some embodiments, the liquid composition comprises no more than 20mg / L Mg+2dissolved therein. According to some embodiments, the liquid composition comprises no more than 10mg / L Mg+2dissolved therein. According to some embodiments, the liquid composition comprises no more than 5mg / L Mg+2dissolved therein. According to some embodiments, the liquid composition comprises no more than 2mg / L Mg+2dissolved therein. According to some embodiments, the liquid composition comprises no more than 1mg / L Mg+2dissolved therein. According to some embodiments, theliquid composition comprises no more than 0.5mg / L Mg+2dissolved therein. According to some embodiments, the liquid composition comprises no more than 0.1mg / L Mg+2dissolved therein. According to some embodiments, the liquid composition provided to step (VI) comprises no more than 500mg / L Mn+2dissolved therein. According to some embodiments, the liquid composition comprises no more than 400mg / L Mn+2dissolved therein. According to some embodiments, the liquid composition comprises no more than 300mg / L Mn+2dissolved therein. According to some embodiments, the liquid composition comprises no more than 200mg / L Mn+2dissolved therein. According to some embodiments, the liquid composition comprises no more than 100mg / L Mn+2dissolved therein. According to some embodiments, the liquid composition comprises no more than 50mg / L Mn+2dissolved therein. According to some embodiments, the liquid composition comprises no more than 20mg / L Mn+2dissolved therein. According to some embodiments, the liquid composition comprises no more than 10mg / L Mn+2dissolved therein. According to some embodiments, the liquid composition comprises no more than 5mg / L Mn+2dissolved therein. According to some embodiments, the liquid composition comprises no more than 2mg / L Mn+2dissolved therein. According to some embodiments, the liquid composition comprises no more than 1mg / L Mn+2dissolved therein. According to some embodiments, the liquid composition comprises no more than 0.5mg / L Mn+2dissolved therein. According to some embodiments, the liquid composition comprises no more than 0.1mg / L Mn+2dissolved therein.

[0343] According to some embodiments, the liquid composition provided to step (VI) comprises no more than 500mg / L dissolved inorganic carbon species dissolved therein. According to some embodiments, the liquid composition comprises no more than 400mg / L dissolved inorganic carbon species dissolved therein. According to some embodiments, the liquid composition comprises no more than 300mg / L dissolved inorganic carbon species dissolved therein. According to some embodiments, the liquid composition comprises no more than 200mg / L dissolved inorganic carbon species dissolved therein. According to some embodiments, the liquid composition comprises no more than 100mg / L dissolved inorganic carbon species dissolved therein. According to some embodiments, the liquid composition comprises no more than 50mg / L dissolved inorganic carbon species dissolved therein. According to some embodiments, the liquid composition comprises no more than 20mg / L dissolved inorganic carbon species dissolved therein. According to some embodiments, the liquid composition comprises no more than 10mg / L dissolved inorganic carbon species dissolved therein. According to some embodiments, the liquid composition comprises no more than 5mg / L dissolved inorganic carbon species dissolved therein. According to some embodiments, the liquid composition comprises no more than 2mg / L dissolved inorganic carbonspecies dissolved therein. According to some embodiments, the liquid composition comprises no more than 1mg / L dissolved inorganic carbon species dissolved therein. According to some embodiments, the liquid composition comprises no more than 0.5mg / L dissolved inorganic carbon species dissolved therein. According to some embodiments, the liquid composition comprises no more than 0.1mg / L dissolved inorganic carbon species dissolved therein.

[0344] According to some embodiments, EX is provided to step (VI) as an aqueous mixture. According to some embodiments, EX is provided to step (VI) as an aqueous solution or suspension. Each possibility represents a separate embodiment of the invention. According to some embodiments, EX is provided to step (VI) as an aqueous solution. According to some embodiments, EX is provided to step (VI) as a concentrated aqueous solution. The variables E and X are detailed herein. According to some embodiments, EX comprises NaCl. According to some embodiments, the NaCl is provided to step (VI) as an aqueous mixture. According to some embodiments, the NaCl is provided to step (VI) as an aqueous solution or suspension. Each possibility represents a separate embodiment of the invention. According to some embodiments, the NaCl is provided to step (VI) as an aqueous solution. According to some embodiments, the NaCl is provided to step (VI) as a concentrated aqueous solution (e.g., brine). According to some embodiments, EX comprises NaNO₃. According to some embodiments, the NaNO₃ is provided to step (VI) as an aqueous mixture. According to some embodiments, the NaNO₃ is provided to step (VI) as an aqueous solution or suspension. Each possibility represents a separate embodiment of the invention. According to some embodiments, the NaNO₃ is provided to step (VI) as an aqueous solution. According to some embodiments, the NaNO₃ is provided to step (VI) as a concentrated aqueous solution.

[0345] According to some embodiments, the liquid composition provided to step (VI) comprises EX at concentration in the range of 0.01M to 5M, including each value and sub-range within the specified range.

[0346] According to some embodiments, subjecting the EX to electrodialysis or electrolysis entails carrying out the following chemical reaction:EX +H2O → HX + EOH.

[0347] According to some embodiments, subjecting the NaX to electrodialysis or electrolysis entails carrying out the following chemical reaction:NNaX +H2O → HX + NaOH.

[0348] According to some embodiments, subjecting the ECI to electrodialysis or electrolysis entails carrying out the following chemical reaction:EECl +H2O → HCl + EOH.

[0349] According to some embodiments, subjecting the ENO3 to electrodialysis or electrolysis entails carrying out the following chemical reaction:EENO3+H2O → HNO3+ EOH.

[0350] According to some embodiments, subjecting the NaCl to electrodialysis or electrolysis entails carrying out the following chemical reaction:NaCl +H2O → HCl + NaOH.

[0351] According to some embodiments, subjecting the NaNOs to electrodialysis or electrolysis entails carrying out the following chemical reaction:NNaNO3+H2O → HNO3+ NaOH.

[0352] According to some embodiments, the electrodialysis of step (VI) is carried out at a temperature of no more than 200°C. According to some embodiments, the electrodialysis of step (VI) is carried out at a temperature of no more than 150°C. According to some embodiments, the electrodialysis of step (VI) is carried out at a temperature of no more than 120°C. According to some embodiments, the electrodialysis of step (VI) is carried out at a temperature of no more than 100°C. According to some embodiments, the electrodialysis of step (VI) is carried out at a temperature of no more than 75°C. According to some embodiments, the electrodialysis of step (VI) is carried out at a temperature of no more than 50°C. According to some embodiments, the electrodialysis of step (VI) is carried out at a temperature of no more than 30°C. According to some embodiments, electrodialysis of step (VI) is carried out at room temperature or less. According to some embodiments, the electrodialysis of step (VI) is carried out at room temperature.

[0353] According to some embodiments, the electrodialysis of step (VI) is carried out at an electrode voltage in the range of 0.5 to 10V. According to some embodiments, the current density is no more than 5 Amper per cm2.

[0354] According to some embodiments, the electrodialysis of step (VI) is carried out at a pH in the range of 4 to 12.

[0355] According to some embodiments, subjecting the EX to electrodialysis or electrolysis entails forming an acid. According to some embodiments, the acid has the formula HX. According to some embodiments, subjecting the EX to electrodialysis or electrolysis entails forming HX. The variable X is defined herein.

[0356] According to some embodiments, the HX is formed in step (VI) as an aqueous mixture. According to some embodiments, the HX is formed in step (VI) as an aqueous solution. According to some embodiments, the HX formed in step (VI) is an aqueous solution of hydrohalic acid. According to some embodiments, the HX formed in step (VI) is an aqueous solution of hydrochloric acid. According to some embodiments, the HX formed in step (VI) is an aqueous solution of nitric acid. According to some embodiments, the HX formed in step (VI) is an aqueous solution of hydrochloric acid or nitric acid.

[0357] According to some embodiments, subjecting the EX to electrodialysis or electrolysis entails forming a base. According to some embodiments, subjecting the EX to electrodialysis or electrolysis entails forming a base comprising E. According to some embodiments, the base is EOH. According to some embodiments, subjecting the EX to electrodialysis or electrolysis entails forming EOH. The variable E is defined herein.

[0358] According to some embodiments, the EOH formed in step (VI) is in the form of an aqueous mixture. According to some embodiments, the EOH formed in step (VI) is in the form of an aqueous solution or suspension. Each possibility represents a separate embodiment of the invention. According to some embodiments, the EOH formed in step (VI) is in the form of an aqueous solution. According to some embodiments, EOH comprises NaOH. According to some embodiments, the NaOH formed in step (VI) is in the form of an aqueous mixture. According to some embodiments, the NaOH formed in step (VI) is in the form of an aqueous solution or suspension. Each possibility represents a separate embodiment of the invention. According to some embodiments, the NaOH formed in step (VI) is in the form of an aqueous solution.

[0359] According to some embodiments, a subsequent step (II), which follows step (VI), comprises reacting the carbonate salt of the metal M with the acid formed in step (VI). According to some embodiments, a subsequent step (II), which follows step (VI), comprises reacting the carbonate salt of the metal M provided in step (I) with the HX formed in step (VI). According to some embodiments, a subsequent step (II), which follows step (VI), comprises reacting thecarbonate salt of the metal M provided in step (I) with the HC1 formed in step (VI). According to some embodiments, a subsequent step (II), which follows step (VI), comprises reacting the carbonate salt of the metal M provided in step (I) with the HNO3 formed in step (VI). According to some embodiments, a subsequent step (II), which follows step (VI), comprises reacting the MCO3 with the acid formed in step (VI). According to some embodiments, a subsequent step (II), which follows step (VI), comprises reacting the MCO3 provided in step (I) with the HX formed in step (VI). According to some embodiments, a subsequent step (II), which follows step (VI), comprises reacting the MCO3 provided in step (I) with the HC1 formed in step (VI). According to some embodiments, a subsequent step (II), which follows step (VI), comprises reacting the MCO3 provided in step (I) with the HNO3 formed in step (VI). According to some embodiments, a subsequent step (II), which follows step (VI), comprises reacting the CaCO, with the acid formed in step (VI). According to some embodiments, a subsequent step (II), which follows step (VI), comprises reacting the CaCCV provided in step (I) with the HX formed in step (VI). According to some embodiments, a subsequent step (II), which follows step (VI), comprises reacting the CaCO3provided in step (I) with the HC1 formed in step (VI). According to some embodiments, a subsequent step (II), which follows step (VI), comprises reacting the CaCO, provided in step (I) with the HNO3 formed in step (VI). According to some embodiments, a subsequent step (II), which follows step (VI), comprises reacting the MgCO, with the acid formed in step (VI). According to some embodiments, a subsequent step (II), which follows step (VI), comprises reacting the MgCCh provided in step (I) with the HX formed in step (VI). According to some embodiments, a subsequent step (II), which follows step (VI), comprises reacting the MgCCh provided in step (I) with the HC1 formed in step (VI). According to some embodiments, a subsequent step (II), which follows step (VI), comprises reacting the MgCO, provided in step (I) with the HNO3 formed in step (VI). According to some embodiments, a subsequent step (II), which follows step (VI), comprises reacting the MnCCh with the acid formed in step (VI). According to some embodiments, a subsequent step (II), which follows step (VI), comprises reacting the MnCCh provided in step (I) with the HX formed in step (VI). According to some embodiments, a subsequent step (II), which follows step (VI), comprises reacting the MnCCh provided in step (I) with the HC1 formed in step (VI). According to some embodiments, a subsequent step (II), which follows step (VI), comprises reacting the MnCCh provided in step (I) with the HNO3 formed in step (VI).

[0360] According to some embodiments, the method further comprises performing steps (I) to (VI), for at least one consecutive cycle, wherein the acid formed in step (VI) is provided as the acid of consecutive step (II). According to some embodiments, the method further comprisesperforming steps (I) to (VI), for at least one consecutive cycle, wherein the HX formed in step (VI) is provided as the acid of consecutive step (II). According to some embodiments, the method further comprises performing steps (I) to (VI), for at least one consecutive cycle, wherein the HC1 formed in step (VI) is provided as the acid of consecutive step (II). According to some embodiments, the method further comprises performing steps (I) to (VI), for at least one consecutive cycle, wherein the HNO3 formed in step (VI) is provided as the acid of consecutive step (II).

[0361] According to some embodiments, a subsequent step (III), which follows step (VI), comprises reacting the residual metal salt with the hydroxide base, EOH, formed in step (VI). According to some embodiments, a subsequent step (V), which follows step (VI), comprises reacting the residual metal salt with the hydroxide base, NaOH, formed in step (VI). According to some embodiments, a subsequent step (III), which follows step (VI), comprises reacting the MX2 with the hydroxide base, EOH, formed in step (VI). According to some embodiments, a subsequent step (V), which follows step (VI), comprises reacting the MX2 with the hydroxide base, NaOH, formed in step (VI). According to some embodiments, a subsequent step (III), which follows step (VI), comprises reacting the CaX2 with the hydroxide base, EOH, formed in step (VI). According to some embodiments, a subsequent step (V), which follows step (VI), comprises reacting the CaX2 with the hydroxide base, NaOH, formed in step (VI). According to some embodiments, a subsequent step (III), which follows step (VI), comprises reacting the MgX2 with the hydroxide base, EOH, formed in step (VI). According to some embodiments, a subsequent step (V), which follows step (VI), comprises reacting the MgX2 with the hydroxide base, NaOH, formed in step (VI). According to some embodiments, a subsequent step (III), which follows step (VI), comprises reacting the MnX2 with the hydroxide base, EOH, formed in step (VI). According to some embodiments, a subsequent step (V), which follows step (VI), comprises reacting the MnX2 with the hydroxide base, NaOH, formed in step (VI).

[0362] According to some embodiments, the method further comprises performing steps (I) to (VI), for at least one consecutive cycle, wherein the EOH formed in step (VI) is provided to consecutive step (III). According to some embodiments, the method further comprises performing steps (I) to (VI), for at least one consecutive cycle, wherein the NaOH formed in step (VI) is provided to consecutive step (III).

[0363] According to some embodiments, the electrodialysis or electrolysis of step (VI) is carried out in a vessel comprising polymeric walls or standard stainless steel. Specifically, in contrast to processes that form HC1 gas, which is hot, corrosive and does not enable the use ofplastic or standard stainless steel reaction vessels, the present method forms HC1 only as aqueous hydrochloric acid, which is much less hot and corrosive and may enable the use of plastic or standard stainless-steel vessels.

[0364] According to some embodiments, step (VI) includes a pre-treatment of the EX (e.g., NaCl) to remove divalent ions that may be harmful to ion exchange membranes and bipolar membranes. According to some embodiments, removal of divalent ions is performed by softening, nanofiltration, ion exchange or other method.

[0365] According to some embodiments, the NaCl electrodialysis of step (VI) further entails forming deionized aqueous mixture. According to some embodiments, the NaCl electrodialysis of step (VI) further entails forming an aqueous mixture of lower salinity than the salinity of the aqueous mixture provided to step (VI). According to some embodiments, the salinity of the aqueous mixture is restored by using pressure filtration to form a retentate with the same salinity as the NaCl solution provided to step (VI).

[0366] According to some embodiments, the NaNO₃ electrodialysis of step (VI) further entails forming deionized aqueous mixture. According to some embodiments, the NaNO₃ electrodialysis of step (VI) further entails forming an aqueous mixture of lower salinity than the salinity of the aqueous mixture provided to step (VI). According to some embodiments, the salinity of the aqueous mixture is restored by using pressure filtration to form a retentate with the same salinity as the NaNO₃ solution provided to step (VI).

[0367] Reference is now made to Figure 2, which shows the electrodialysis system, according to some embodiments.

[0368] Figure 2 makes a specific reference to electrodialysis of sodium chloride. However, it is to be understood that this is exemplary, and the disclosure provides alternatives to sodium chloride, e.g., sodium nitrate. The electrodialysis system of Figure 2 is an exemplary standard electrodialysis system, which is configured to form an acidic solution of HC1 and a basic solution of NaOH from the NaCl of step (V). Electrodialysis apparatuses are typically composed of two electrodes, an anode and a cathode, separated from one another by one or more ion-selective membranes. Ion-selective membranes suitable for use in the present invention include, but are not limited to, anion-selective, cation-selective and bipolar membranes. Each possibility represents a separate embodiment.

[0369] Thus, the system comprises an anode, a cathode, an anion exchange membrane, a cation exchange membrane, an aqueous NaCl chamber, an acid chamber and a base chamber,according to some embodiments. According to some embodiments, the anion exchange membrane is positioned to separate between the aqueous NaCl chamber and the anode, wherein the acid chamber is defined there between. According to some embodiments, upon application of electric potential, the negative chloride ions of the NaCl flow toward the anode and are separated from the aqueous NaCl chamber in the acid chamber as HCl. According to some embodiments, the cation exchange membrane is positioned to separate between the aqueous NaCl chamber and the cathode, wherein the base chamber is defined there between. According to some embodiments, upon application of electric potential, the positive sodium ions of the NaCl flow toward the cathode and are separated from the aqueous NaCl chamber in the base chamber as NaOH.

[0370] According to certain embodiments, electrodialysis in step (VI) is bipolar membrane electrodialysis (BPMED). According to some embodiments, electrodialysis in step (VI) is electro-electrodialysis (EED).

[0371] As used herein, the term “bipolar membrane electrodialysis” (BPMED) refers to an electrodialysis process that employs bipolar ion-exchange membranes configured to generate an acid and a base from a salt solution upon the application of an electric potential. BPMED may be used in step (VI) to regenerate the acid HX and the base EOH from the EX composition and does not impose any limitation on the specific membrane type, stack configuration, or operational mode employed.

[0372] In some embodiments, the aqueous NaCl, comprising the monovalent NaCl salt is introduced into the aqueous NaCl chamber and the monovalent Na+cations are transported from the aqueous NaCl chamber to the base chamber through the cation exchange membrane to produce a base NaOH solution comprising the monovalent Na+cations. Simultaneously, Cl⁻ anions are transported through the anion exchange membrane to the acid chamber to produce the acid solution comprising the hydrochloric acid, HCl. The respective base and acid solutions can then be utilized for further processes, as described herein.

[0373] In other embodiments, the aqueous NaCl comprising the monovalent NaCl salt is introduced into the aqueous NaCl chamber where the acid is formed and the monovalent Na+cations are transported from the aqueous NaCl chamber to the base chamber through the cation exchange membrane to produce a base solution comprising the monovalent Na+cations. In other embodiments, the aqueous NaCl comprising the monovalent NaCl salt is introduced into the aqueous NaCl chamber where the base is formed and the monovalent Cl⁻ anions are transportedfrom the aqueous NaCl chamber to the acid chamber through the anion exchange membrane to produce an acid solution comprising the monovalent Cl’ anions.

[0374] Within the scope of the present invention are electrodialysis modes of operation such as water-splitting electrodialysis (WSED), electro-electrodialysis (EED), and bipolar membrane electrodialysis (BPMED). Each possibility represents a separate embodiment. Currently preferred is the use of BPMED whereby a bipolar membrane is utilized to convert a saline solution comprising the monovalent salt into the corresponding acid and base under the influence of an electrical field.

[0375] While electrodialysis can be performed at room temperatures, it can also be performed at elevated temperatures. Suitable temperatures at which electrodialysis can be performed include from about 20°C to about 80°C, for example from about 40°C to about 70°C, including each value within the specified ranges. Exemplary temperatures for performing the electrodialysis include, but are not limited to, about 20°C, about 25°C, about 30°C, about 35°C, about 40°C, about 45°C, about 50°C, about 55°C, about 60°C, about 65°C, about 70°C, about 75°C, and about 80°C. Each possibility represents a separate embodiment.

[0376] As contemplated herein, in some embodiments, step (VI) comprises performing an electrolysis of the aqueous NaCl of step (V). According to some embodiments, the electrolysis it a chlor-alkali process. In accordance with these embodiments, the chloride ions of the NaCl undergo oxidation on the anode to form chlorine (Cl₂). At the cathode, water is reduced to hydroxide and hydrogen gas. The net process is the electrolysis of an aqueous solution of NaCl into sodium hydroxide (NaOH), hydrogen gas, and chlorine gas. Thus, according to some embodiments, step (VI) comprises performing an electrolysis of the NaCl of step (V) to form a basic solution of NaOH, hydrogen gas, and chlorine gas.

[0377] Although some embodiments of the present method relate to a batch reaction, it is to be understood that the present method may be carried out continuously.

[0378] According to some embodiments, the method comprises performing steps (I)-(VI) continuously. According to some embodiments, the method comprises performing steps (I)-(VI) repeatedly.

[0379] According to some embodiments, each one of the steps of the method is performed at a temperature of 200°C or less. According to some embodiments, each one of the steps of the method is performed at a temperature of 150°C or less. According to some embodiments, each one of the steps of the method is performed at a temperature of 120°C or less.

[0380] According to some embodiments, at least one of the method steps is performed within a reactor, which comprises walls made from a polymer. According to some embodiments, at least one of the method step is performed within a reactor, which comprises walls made from stainless steel. According to some embodiments, each one of the steps of the present method is performed within a reactor, which comprises walls made from a polymer or within a reactor, which comprises walls made from stainless steel.

[0381] Examples

[0382] Example 1 – Pure Limstone

[0383] A carbonate salt of calcium (CaCCE) is provided as the metal M. The initial dissolution step involves reacting the calcium carbonate with hydrochloric acid (HC1) to form calcium chloride (CaCh) and carbon dioxide (CO2). An excess of 1.05% HC1 (i.e., 2.024 mol of HC1 per mol of CaCO3) is used for the dissolution step.

[0384] Next, the residual calcium chloride solution is reacted with sodium hydroxide (NaOH). An excess of 10.0% NaOH (i.e., 2.2 mol of NaOH per mol of Ca(OH)2 formed) is added to form solid calcium hydroxide (Ca(OH)2) and an aqueous solution comprising calcium hydroxide and sodium chloride (NaCl). The solid, which includes Ca(OH)2 is then separated from the solution via filtration. The calcium concentration in the solution after this separation step is 200-550 mg / L.

[0385] The NaCl solution is then transferred to a fluidized bed reactor (FBR) for precipitation of residual Ca+2as carbonate. The precipitation is expedited by introducing nucleation seeds of calcium carbonate (CaCO3) into the fluidized bed reactor. In the FBR, CO2 is added to a CC Ca molar ratio of 1.3-1.9, resulting in the formation and precipitation of solid CaCO₃. The calcium concentration at the FBR outlet is 1-2 mg / L. The solid CaCO₃ is then separated from the aqueous solution via filtration.

[0386] The separated aqueous solution comprises sodium chloride and has a dissolved inorganic carbon (DIC) concentration of 90-150 mg / L as C. For stripping the DICs from the solution, HC1 is added to reduce the pH to 3.5-5.5 and to remove any residual dissolved inorganic carbon species as CO2. Following the stripping stage, the resulting DIC concentration is 10-30 mg / L as C.

[0387] The resulting aqueous solution comprises NaCl, which is then subjected to electrodialysis using a bipolar membrane. The electrodialysis process regenerates NaOH and HC1, each with a molarity of IM.

[0388] Example 2 - Limestone With Magnesium Separation Step

[0389] A carbonate salt comprising calcium carbonate (CaCO₃ - 98.3% and magnesium carbonate (MgCO₃ -1.7%) is provided as the metal M. The initial dissolution step involves reacting the carbonate salt with hydrochloric acid (HC1) to form calcium chloride (CaCh), magnesium chloride (MgCh), and carbon dioxide (CO2). An excess of 1.05% HC1 equivalents (i.e., 2.1 mol of HC1 per mol of CaCO₃ or MgCO₃) is used for the dissolution step.

[0390] Next, the residual calcium and magnesium chloride solution is reacted with sodium hydroxide (NaOH) to remove magnesium impurities. The solution pH is elevated to 10.3-10.6 and the solids formed are separated via filtration.

[0391] The residual calcium and magnesium chloride solution is then reacted with additional sodium hydroxide. A total excess of 10.0% NaOH equivalents (i.e., 2.2 mol of NaOH per mol of Ca(OH)2 and Mg(OH)2 precipitates) is added across both NaOH addition stages to form solid calcium hydroxide (Ca(OH)2) and an aqueous solution comprising calcium hydroxide and sodium chloride (NaCl). The pure Ca(OH)2 solid is then separated from the solution via filtration. The calcium concentration in the solution after this separation step is 200-550 mg / L.

[0392] The NaCl solution is then transferred to a fluidized bed reactor (FBR) for precipitation of residual Ca+2as calcium carbonate. The precipitation is expedited by the introduction of nucleation seeds of calcium carbonate (CaCO₃) within a fluidized bed reactor. In the FBR, CO₂ is added to a CO₂ / Ca molar ratio of 1.3-1.9, resulting in the formation and precipitation of solid CaCO₃. The calcium concentration at the FBR outlet is 1-2 mg / L. The solid CaCO₃ is then separated from the aqueous solution via filtration.

[0393] The separated aqueous solution comprises sodium chloride and has a dissolved inorganic carbon (DIC) concentration of 90-150 mg / L as C. For stripping the DICs from the solution, HC1 is added to reduce the pH to 3.5-5.5 and to remove residual dissolved inorganic carbon species as CO2. Following the stripping stage, the resulting DIC concentration is 10-30 mg / L as C.

[0394] The resulting aqueous solution comprises NaCl, which is then subjected to electrodialysis using a bipolar membrane. The electrodialysis process regenerates NaOH and HC1, each with a molarity of 0.7-1 M.

[0395] Example 3 - Limestone Without Magnesium Separation Step

[0396] A carbonate salt comprising calcium carbonate (CaCO₃ - 98.3% and magnesium carbonate (MgCO₃ -1.7%) is provided as the metal M. The initial dissolution step involvesreacting the carbonate salt with hydrochloric acid (HC1) to form calcium chloride (CaCh), magnesium chloride (MgCh), and carbon dioxide (CO2). An excess of 1.05% HC1 equivalents (i.e., 2.1 mol of HC1 per mol of CaCO3or MgCCh) is used for the dissolution step.

[0397] The residual calcium and magnesium chloride solution is reacted with sodium hydroxide (NaOH). A total excess of 10.0% NaOH equivalents (i.e., 2.2 mol of NaOH per mol of Ca(OH)2 and Mg(OH)2 precipitates) is added across the NaOH addition stages to form solid calcium hydroxide (Ca(OH)2), magnesium hydroxide (Mg(OH)2) and and sodium chloride (NaCl). The combined Ca(OH)2 and Mg(OH)2 solids are then separated from the solution via filtration. The calcium concentration in the solution after this separation step is 200-550 mg / L.

[0398] The Ca(OH)2-containing solution is transferred to a fluidized bed reactor (FBR) for precipitation of calcium ions (Ca+2as calcium carbonate). The precipitation is expedited by the introduction of nucleation seeds of calcium carbonate (CaCO₃) in the fluidized bed reactor. In the FBR, CO₂ is added to a CO₂ / Ca molar ratio of 1.3-1.9, resulting in the formation and precipitation of solid CaCO₃. The calcium concentration at the FBR outlet is 1-2 mg / L. The solid CaCO₃ is then separated from the aqueous solution via filtration.

[0399] The separated aqueous solution comprises sodium chloride (NaCl) and has a dissolved inorganic carbon (DIC) concentration of 90-150 mg / L as C. For stripping the DICs from the solution, HC1 is added to reduce the pH value to 3.5-5.5 and to remove residual dissolved inorganic carbon species as CO2. Following the stripping stage, the resulting DIC concentration is 10-30 mg / L as C.

[0400] The resulting aqueous solution comprises NaCl, which is then subjected to electrodialysis using a bipolar membrane. The electrodialysis process regenerates NaOH and HC1, each with a molarity of 0.7-1M.

[0401] Example 4 - Dolomite With Magnesium Separation

[0402] A carbonate salt comprising calcium carbonate (CaCO₃ - 51.3% and magnesium carbonate (MgCO₃ -48.7%) is provided as the metal M. The initial dissolution step involves reacting the carbonate salt with hydrochloric acid (HC1) to form calcium chloride (CaCh), magnesium chloride (MgCh), and carbon dioxide (CO2). An excess of 1.05% HC1 equivalents (i.e., 2.1 mol of HC1 per mol of CaCO₃ or MgCO₃) is used for the dissolution step.

[0403] hydroxide (NaOH) to remove magnesium precipitates. The solution pH is elevated to 10.3-10.6, and the solids formed are separated via filtration. In this step, 97%-99% of the magnesium is removed.

[0404] The residual calcium chloride solution is reacted with additional sodium hydroxide. A total excess of 10.0% NaOH equivalents (i.e., of 2.2 mol of NaOH per mol of Ca(OH)2 and Mg(OH)2 precipitates) is added after both NaOH addition stages to form solid calcium hydroxide (Ca(OH)2) and an aqueous solution comprising calcium hydroxide and sodium chloride (NaCl). The pure Ca(OH)2 solid is then separated from the solution via filtration. The calcium concentration in the solution after this separation step is 200-550 mg / L.

[0405] The NaCl solution is transferred to a fluidized bed reactor (FBR) for precipitation of residual Ca+2as calcium carbonate. The precipitation is expedited by introducing nucleation seeds of CaCO₃ into the fluidized bed reactor. In the FBR, CO₂ is added to a CO₂ / Ca molar ratio of 1.3-1.9, resulting in the formation and precipitation of solid CaCO₃. The calcium concentration at the FBR outlet is 1-2 mg / L. The solid CaCO₃ is then separated from the aqueous solution via filtration.

[0406] The separated aqueous solution comprises sodium chloride (NaCl) and has a dissolved inorganic carbon (DIC) concentration of 90-150 mg / L as C. For stripping the DICs from the solution, HC1 is added to reduce the pH to 3.5-5.5 and to remove any residual dissolved inorganic carbon species as CO2. Following the stripping stage, the resulting DIC concentration is 10-30 mg / L as C.

[0407] The resulting aqueous NaCl solution is then subjected to electrodialysis using a bipolar membrane. The electrodialysis process regenerates the NaOH and HC1, each with a molarity of IM.

[0408] Example 5 - MgfOHL Extraction From Magnesite

[0409] A carbonate mineral containing magnesium, silica, calcium, and iron (MgCOs -92.0%, SiO2 - 3.5%, CaCOs -2.5%, Fe2O3-l.l% and AI2O3 -0.9%) is provided. The initial dissolution step involves reacting the carbonate salt and the associated impurities with hydrochloric acid (HC1) to form a chloride-based solution (mainly MgCh and CaCh) and carbon dioxide (CO2). An excess of 1.05% HC1 equivalents (i.e., 2.1 mol of HC1 per mol of CaCO₃ and MgCO₃ and 6.3 mol of HCl per mol of Fe₂O₃ and Al₂O₃) is used for the dissolution step.

[0410] Next, the residual solution is reacted with sodium hydroxide (NaOH) to remove iron and aluminium precipitates. The solution pH is elevated to 4.0-4.5 and the solids formed are separated via filtration.

[0411] The residual magnesium and calcium chloride solution is then reacted with additional sodium hydroxide. A total excess of 10.0% NaOH equivalents (i.e., of 2.2 mol of NaOH per molMg(OH)2 precipitates, 6.6 mol of NaOH per mol Fe(OH)3 and A1(OH)3) is added after both NaOH addition stages to form solid magnesium hydroxide (Mg(OH)2) and an aqueous solution comprising calcium hydroxide, calcium chloride, and sodium chloride (NaCl). The pure Mg(OH)2 solid is then separated from the solution via filtration.

[0412] The NaCl solution is then transferred to a fluidized bed reactor (FBR) for precipitation of the remaining Ca+2as carbonate. The precipitation is expedited by introducing nucleation seeds of calcium carbonate (CaCO3) into the fluidized bed reactor. In the FBR, CO2 is added at a CC Ca molar ratio of 1.3-1.9, resulting in the formation and precipitation of solid CaCO,. The calcium concentration at the FBR outlet is 1-2 mg / L. The solid CaCO3is then separated from the aqueous solution via filtration.

[0413] The separated aqueous solution comprises sodium chloride and has a dissolved inorganic carbon (DIC) concentration of 90-200 mg / L as C. For stripping the DICs from the solution, HC1 is added to reduce the pH to 3.5-5.5 and to remove any residual dissolved inorganic carbon species as CO2. Following the stripping stage, the resulting DIC concentration is 10-30 mg / L as C.

[0414] The resulting aqueous solution comprises NaCl, which is then subjected to electrodialysis using a bipolar membrane. The electrodialysis process regenerates NaOH and HC1, each with a molarity of IM.

[0415] Example 6 - Mn(0H)2 Extraction From Manganese Carbonate

[0416] A carbonate mineral containing manganese, calcium, magnesium, and iron (MnCOs - 95.1%, CaCOs -2.8%, MgCOs -1.6%, and Fe2O3 -0.5%) is provided. The initial dissolution step involves reacting the carbonate salt and impurities with hydrochloric acid (HC1) to form a chloride-based solution (mainly MnCh, CaCh and MgCh) and carbon dioxide (CO2). An excess of 1.05% HC1 equivalents is used (i.e., 2.1 mol of HC1 per mol of MnCCL, CaCCL and MgCCL and 6.3 mol of HC1 per mol of Fe2O3 and AI2O3) for the dissolution step.

[0417] Next, the residual solution is reacted with sodium hydroxide (NaOH) to remove iron precipitates. The solution pH is elevated to 4.5-5.0 and the solids formed are separated via filtration.

[0418] The residual solution is then reacted again with sodium hydroxide (NaOH) to form and separate manganese hydroxide (Mn(0H)2 precipitates. The solution pH is elevated to 8.7-9.3 and the resulting Mn(OH)2-contaning solids are separated via filtration.

[0419] The remaining solution is then reacted with additional sodium hydroxide to remove magnesium hydroxide (Mg(OH)2) impurities. A total excess of 10.0% NaOH equivalents (i.e., 2.2 mol of NaOH per mol Mn(0H)2 and Mg(OH)2 precipitates and 6.6 mol of NaOH per mol Fe(OH)3) is added across the three NaOH addition stages.

[0420] The NaCl solution is transferred to a fluidized bed reactor (FBR) for precipitation of the remaining Ca+2as carbonate. The precipitation is expedited by the introduction of nucleation seeds of calcium carbonate (CaCO₃) into the fluidized bed reactor. In the FBR, CO₂ is added at a CO₂ / Ca molar ratio of 1.3-1.9, resulting in the formation and precipitation of solid CaCO₃. The calcium concentration at the FBR outlet is 1-2 mg / L. The solid CaCO₃ is then separated from the aqueous solution via filtration.

[0421] The separated aqueous solution comprises sodium chloride and has a dissolved inorganic carbon (DIC) concentration of 90-200 mg / L as C. For stripping the DICs from the solution, HC1 is added to reduce the pH to 3.5-5.5 and remove any residual dissolved inorganic carbon species as CO2. Following the stripping stage, the resulting DIC concentration is 10-30 mg / L as C.

[0422] The resulting aqueous solution comprises NaCl, which is then subjected to electrodialysis using a bipolar membrane. The electrodialysis process regenerates the NaOH and HC1, each with a molarity of IM.

[0423] A consolidated summary of the materials, compositions, processing conditions, and metal-removal efficiencies associated with Examples 1-6 is provided in Figure 3.

[0424] The foregoing description of the specific embodiments will so fully reveal the general nature of the invention that others can, by applying current knowledge, readily modify and / or adapt for various applications such specific embodiments without undue experimentation and without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. The means, materials, and steps for carrying out various disclosed functions may take a variety of alternative forms without departing from the invention.

Claims

CLAIMS1. A method for producing a metal hydroxide from a metal carbonate, the method comprising the steps of:(I) providing a carbonate salt of a metal M, wherein M is:an alkaline earth metal selected from the group consisting of: calcium, magnesium, strontium and barium;a transition metal or post-transition metal, selected from the group consisting of: manganese, cobalt, copper, zinc, lead and bismuth; oran actinide or lanthanide selected from the group consisting of: lanthanum, uranium, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, erbium, holmium, thulium, lutetium and ytterbium;(II) reacting the carbonate salt provided in step (I) with an acid, having the formula HX, wherein X is selected from the group consisting of: halide, NOf, HSO4', HCO3; H2PO3; CH3COO’ and HCOO’,to obtain CO2 and a residual metal salt, which comprises M and at least one X’ anion;(III) reacting the residual metal salt with a monovalent base EOH, wherein E is an alkali metal, at a predetermined pH, to form a hydroxide salt of the metal M and an alkali salt EX, thereby resulting in:a first liquid phase comprising the EX and a first portion of the hydroxide salt of the metal M; anda first precipitate comprising a second portion of the hydroxide salt of the metal M;(IV) separating the first precipitate from the first liquid phase;(Va) contacting the separated first liquid phase with CO2, thereby reacting the first portion of the hydroxide salt of the metal M with CO2, to form:a second liquid phase comprising the EX, anda second precipitate comprising the carbonate salt of the metal M;(Vb) separating the second precipitate from the second liquid phase; and(VI) subjecting the separated second liquid phase to electrolysis or electrodialysis thereby regenerating the base of step (III), EOH, and the acid of step (II), HX;wherein the liquid composition provided to step (VI) comprises no more than 500mg / L ions of the metal M dissolved therein.

2. The method according to claim 1, wherein the carbonate salt of a metal M is selected from the group consisting of: CaCO3, MgCO3, SrCO3, BaCO3, MnCO3, CoCOs, CuCO3, ZnCO3, PbCO3, (BiO)2CO3, Lu2(CO3)3, La2(CO3)3, UO2CO3, Ce2(CO3)3, Pr2(CO3)3, Nd2(CO3)3, Sm2(CO3)3, Eu2(CO3)3, Gd2(CO3)3, Tb2(CO3)3, Dy2(CO3)3, Er2(CO3)3, Ho2(CO3)3, Tm2(CO3)3, and Yb2(CO3)3.

3. The method according to claim 2, wherein M is Ca, Mg, or Mn.

4. The method according to claim 3, wherein M is Ca and the carbonate salt provided to step (I) is CaCO3.

5. The method according to any one of claims 1 to 4, wherein the CO2formed in step (II) is in a gas form, and step (II) comprises isolating and storing at least a portion the CO2gas thus obtained.

6. The method according to any one of claims 1 to 5, wherein the residual metal salt has the formula MX2, wherein the carbonate salt of a metal M has the formula MCO3, and wherein reacting the MCO3with the acid in step (II) entails carrying out the chemical reaction:MCO3+ 2HX → MX2+ CO2+ H2O.

7. The method according to any one of claims 1 to 6, wherein the acid in step (II) is provided as an aqueous solution of HX.

8. The method according to any one of claims 1 to 7, wherein the acid in step (II) is selected from the group consisting of hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, carbonic acid, phosphoric acid, and combinations thereof.

9. The method according to any one of claims 1 to 8, wherein the acid in step (II) comprises hydrochloric acid, nitric acid or both.

10. The method according to claim 9, wherein the hydrochloric acid or nitric acid has a concentration in the range of 0.01M to 5M.

11. The method according to any one of claims 9 to 10, wherein the carbonate salt of a metal M has the formula MCO3, wherein reacting the MCO3 with the acid in step (II) entails carrying out at least one of the following chemical reactions:MCO3+ 2HCl → CO2+ H2O + MCl2;andMCO3 + 2HNO3CO2+ H2O + M(NO3)2;thereby producing CO2and MCl2or M(NO3)2as the residual metal salt.

12. The method according to any one of claims 1 to 11, wherein the residual metal salt is formed in step (II) as an aqueous solution.

13. The method according to claim 12, wherein the residual metal salt is formed in step (II) as an aqueous solution having a concentration of the residual metal salt in the range of 0.005M to 2.5M.

14. The method according to any one of claims 1 to 13, wherein step (III) further comprises providing the monovalent base EOH as an aqueous solution.

15. The method according to any one of claims 1 to 14, wherein step (III) comprises reacting the residual metal salt with excess monovalent base EOH.

16. The method according to any one of claims 1 to 15, wherein step (III) comprises reacting the residual metal salt with the monovalent base EOH at a mol ratio in the range of 1:2 to 1:25.

17. The method according to any one of claims 1 to 16, wherein the residual metal salt formed in step (II) has the formula MX2, wherein reacting MX2 with EOH in step (III) entails carrying out the following chemical reaction:MX2+ 2EOH → M(OH)2+ 2EX.

18. The method according to claim 17, wherein the residual metal salt is CaCl2or Ca(NO3)2, E is Na and reacting the residual metal salt in step (III) entails carrying out at least one of the following chemical reactions:CaCl2+ 2NaOH → Ca(OH)2+ 2NaCl; andCa(NO3)2+ 2NaOH Ca(OH)2+ 2NaNO3,thereby producing Ca(OH)2and sodium chloride or sodium nitrate.

19. The method according to any one of claims 1 to 18, wherein the predetermined pH is in the range of 7 to 14.

20. The method according to any one of claims 1 to 19, wherein the first liquid phase formed in step (III) is aqueous and has pH in the range of 7 to 14.

21. The method according to any one of claims 1 to 20, wherein the first liquid phase formed in step (III) comprises 0.5mg / L to 5000mg / L hydroxide salt of the metal M dissolved therein as the first portion.

22. The method according to any one of claims 1 to 21, wherein a ratio between the first portion of the hydroxide salt of the metal M and the second portion of the hydroxide salt of the metal M is in the range of 0.000002 to 0.2.

23. The method according to any one of claims 1 to 22, wherein E is an alkali metal cation.

24. The method according to claim 23, wherein E is Na+.

25. The method according to any one of claims 1 to 24, wherein separating the first precipitate from the first liquid phase in step (IV) comprises filtering the first precipitate from the first liquid phase.

26. The method according to any one of claims 1 to 25, wherein the CO2formed in step (II) is in a gas form, and step (Va) comprises contacting the separated first liquid phase with a portion of the CO2formed in step (II), or with an aqueous solution comprising bicarbonate ions, carbonate ions, or both, wherein said aqueous solution is formed by contacting a portion of the CO2formed in step (II) with a portion of the base, EOH, formed in step (IV).

27. The method according to any one of claims 1 to 26, wherein the first portion of the hydroxide salt of the metal M comprises M(0H)2, wherein reacting the M(0H)2 with the CO2 in step (Va) entails carrying out at least one of the following chemical reactions:M(OH)2+ CO2→ MCO₃ + H2O;M(OH)2+ HCO3⁻ → MCO₃ + H₂O + OH⁻; andM(0H)2+ CO3-2MCO3 + 2OH'28. The method according to any one of claims 1 to 27, wherein the second precipitate comprises CaCO3.

29. The method according to any one of claims 1 to 28, wherein the second liquid phase comprises no more than 500mg / L metal M in an ionized form dissolved therein.

30. The method according to any one of claims 1 to 29, wherein the second liquid phase comprises no more than 200mg / L Ca+2dissolved therein.

31. The method according to any one of claims 1 to 30, wherein the second liquid phase comprises 0.1M to 5M EX dissolved therein.

32. The method according to any one of claims 1 to 31, wherein separating the second precipitate from the second liquid phase in step (Vb) comprises filtering the second precipitate from the second liquid phase.

33. The method according to any one of claims 1 to 32, further comprising performing steps (I) to (VI), for at least one consecutive cycle, wherein the carbonate salt of the metal M separated in step (Vb) is provided to step (II).

34. The method according to any one of claims 1 to 33, wherein the separated second liquid phase comprises residual dissolved inorganic carbon species, andwherein the method further comprises step (Vc) of contacting the separated second liquid phase with an acid, having the formula HX, wherein X is selected from the group consisting of: halide, NO3-, HSO4-, HCO3-, H2PO3-, CH3COO-and HCOO-,thereby removing the residual dissolved inorganic carbon species from the separated second liquid phase as CO2.

35. The method according to claim 34, wherein the acid in step (Vc) is hydrochloric acid or nitric acid.

36. The method according to any one of claims 34 to 35, further comprising performing steps (I) to (VI), for at least one consecutive cycle, wherein a portion of the acid formed in step (VI) is provided to consecutive step (Vc).

37. The method according to any one of claims 34 to 36, further comprising performing steps (I) to (VI), for at least one consecutive cycle, wherein the CO2 formed in step (Vc) is provided to consecutive step (Va).

38. The method according to any one of claims 1 to 37, wherein the separated second liquid phase provided to step (VI) comprises no more than 500mg / L dissolved inorganic carbon species dissolved therein.

39. The method according to any one of claims 1 to 38, wherein the second liquid phase provided to step (VI) comprises no more than 200mg / L salts of the metal M dissolved therein.

40. The method according to any one of claims 1 to 39, wherein the second liquid phase provided to step (VI) comprises no more than 200mg / L Ca+2.

41. The method according to any one of claim 1 to 40, wherein EX is ECI or ENO3, and the electrodialysis or electrolysis is according to one of the following schemes:ECl +H2O → HCl + EOHandENO3+H2O → HNO3+ EOH.

42. The method according to any one of claims 1 to 41, further comprising performing steps (I) to (VI), for at least one consecutive cycle, wherein the EOH formed in step (VI) is provided as the hydroxide base EOH of consecutive step (III).

43. The method according to any one of claims 1 to 42, wherein X is Cl’ or NCE', E is Na+, and the electrodialysis or electrolysis is according to at least one of the following schemes:NaCl +H2O → HCl + NaOHandNaNO3+H2O → HNO3+ NaOH.

44. The method according to any one of claims 1 to 43, wherein the HX formed in step (VI) is in the form of an aqueous solution.

45. The method according to any one of claims 1 to 44, further comprising performing steps (I) to (VI), for at least one consecutive cycle, wherein the HX formed in step (VI) is provided as the acid of consecutive step (II).

46. The method according to any one of claims 1 to 45, wherein each one of the steps is performed at a temperature of 200°C or less.

47. The method according to any one of claims 1 to 46, wherein each one of the steps is performed at a temperature of 150°C or less.

48. The method according to any one of claims 1 to 47, wherein each one of the steps is performed at a temperature of 120°C or less.

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