Method for preparing amorphous calcium carbonate by fixation of carbon dioxide

Abstract

The present invention provides a method for fixing carbon dioxide and a method for preparing stabilized amorphous alkaline earth metal carbonates.

Description

[Technical Field]

[0001] The present invention relates to a method for preparing stabilized amorphous calcium carbonate using and fixing carbon dioxide gas. [Background technology]

[0002] Climate change is recognized as a major challenge for modern society. Generally caused by greenhouse gases, most commonly carbon dioxide (CO2), is the main cause of global warming. More than 40% of energy-related CO2 emissions come from the burning of fossil fuels to generate electricity.

[0003] Inorganic carbonation processes have previously been proposed and even implemented, primarily to sequester CO2 generated by power plants and other energy-intensive manufacturing facilities. In these cases, the idea is to capture emitted CO2 in a controlled manner and then release it again in a controlled manner by filling CO2 reservoirs, dumping them in the deep sea, or absorbing them in specific geological compositions. Existing methods have drawbacks, such as energy consumption, efficiency, and cost of the process (partly due to the high cost of inorganic reagents). They are also based on the use of capture agents, such as Ca(OH)2 and CaO, produced by releasing CO2 from mined CaCO3, or ammonia. These processes also require the CO2 to be released and captured somewhere in an energy-intensive process, while there is still a need to dispose of this CO2 somewhere on Earth ("storage") or convert it into useful organic products. The latter concept has already been studied for 40 years without large-scale implementation, low energy consumption, or any useful possibility for commercializing the resulting products.

[0004] Under basic conditions (i.e., high pH, ​​high concentration of OH -It is well known that in aqueous solutions, CO can be converted to bicarbonate or carbonate (depending on the pH). It is also known that calcium ion salts, such as calcium chloride and calcium nitrate in particular, can be converted to Ca(OH), which can then react with CO to form crystalline CaCO.

[0005] The solubility of CO2 at atmospheric pressure and 25°C is very low, with approximately 1.5 g of CO2 dissolving in 1 L of water at atmospheric pressure. The low solubility of CO2 in water at room temperature and atmospheric pressure makes it impractical to capture large amounts of rapidly released CO2 with calcium reagents such as CaCl2·2H2O, calcium nitrate, and Ca(OH)2 unless the pressure is increased in a sealed reactor.

[0006] A graph of CO2 solubility versus pressure generally demonstrates that at 1 atm, the solubility in water is about 1.5 g CO2 per Kg water at 25°C, although this varies somewhat depending on the water content. When CO2 is pressurized, the solubility increases dramatically. At about 50 atmospheres, the solubility reaches over 50 g CO2 per Kg water. Therefore, one way to increase the efficiency of the process described in this invention is to introduce CO2 in a pressurized mode.

[0007] Chemical equilibrium shifts the conversion reaction from primarily CO2 at pH 5 to primarily (more than 90%) bicarbonate and eventually carbonate ions at pH levels 7 and 11, respectively. At pH levels below 4 and 5, CO2 is converted to carbonic acid, which increases the acidity of the aqueous solution and keeps most of the CO2 in its original form.

[0008] The mass production of other carbonates and minerals can involve the mass production of CaCl and CaSO hydrate as industrial waste. For example, CaCl is a by-product of soda ash (NaCO) in a process known as the "Solvay Process." Park et al. (Journal of Hazardous Materials 403 (2021) 123862) disclose the use of a process that converts Ca(OH) to calcium carbonate by reacting it with CO. If such industrial waste could be reused at no cost, or at least partially, the economics of capturing CO in any form of calcium carbonate would outweigh the costs associated with continuous CO capture.

[0009] Due to global industrialization in parallel with dangerous greenhouse effect and climate change, there is an urgent need to develop new technologies to remove CO2 from the atmosphere. Summary of the Invention

[0010] It has been unexpectedly discovered that by adjusting the physicochemical conditions, it is possible to fix CO2 gas and produce large amounts of stabilized amorphous calcium carbonate at room temperature in an industrially useful manner. In the laboratory-scale reaction provided in the examples, approximately 3.8 g of CO2 was mixed with approximately 13 g of CaCl2 in the presence of a stabilizer such as tripolyphosphate (as a representative stabilizer) to synthesize ACC. . 2H2O, CO2 reacts with CO3 - A total yield of 10.5 g was obtained in a 250 mL reaction volume solution at room temperature, provided that ACC was converted to ACC. The examples show that it is possible to achieve up to 90% yield of ACC production and 90% phase purity (i.e., amorphous material). In the present invention, the yield was shown to be increased by adding CO2 to a basic solution as a first step to obtain a soluble form of (Na)2CO3 in situ. Alternatively, a base can be added to a solution of calcium chloride or calcium nitrate to convert them in situ to calcium hydroxide, which can capture CO2 and form ACC in the presence of a stabilizer.

[0011] Furthermore, it is possible to increase the yield of ACC production by changing the schedule for adding the stabilizer and / or by increasing the pH of the reaction. As shown in Example 2, adding the stabilizer in two different stages increases the yield.

[0012] Without being limited to any particular theory, it is estimated that three to four equilibrium reactions occur.

[0013] The main reactions are as follows:

[0014] [ka]

[0015] Further reactions that may occur after addition of CaCl are as follows:

[0016] [ka]

[0017] It was concluded that under laboratory conditions, the reaction can be completed in less than two minutes. Similar reactions can also be carried out in the presence of dissolved ammonia (hence, NH4OH). NH4OH refers to the product of dissolving ammonia (NH3) in water. Thus, reactions with this base can be handled by using pre-dissolved ammonia, already defined as NH4OH, or by bubbling or pressurizing ammonia directly into the reaction solution to form NH4OH in situ.

[0018] By fixing CO2 and converting CaCl2 to ACC, the present invention actually solves three problems: fixing environmentally harmful CO2, disposing of CaCl2 waste, and producing large amounts of ACC. ACC, when produced at a lower purity than required for use as a food supplement or pharmaceutical, can be used in agriculture, for example, as a crop fertilizer, as a supplement for livestock, etc. In some industrial processes, calcium oxide can be produced as a by-product. It can be used to form cement and glass, but it can also be used to form calcium hydroxide, which can be converted to ACC according to the present invention. A similar process can be used to convert MgCl2 to ACC in the presence of a base, stabilizers, and CO2 bubbling. 2、 This can be done by using Mg(NO3)2, MgSO4, Mg(OH)2, and MgO waste to obtain an amorphous magnesium carbonate phase.

[0019] It is important to maintain an adequately high pH (above 8) throughout the process by adding sufficient base (at least two equivalents of calcium present in the reaction) or by continuous or incremental addition of base to maintain a pH above 8, preferably above 11. Generally, it is possible to achieve calcium carbonate precipitate formation below pH 10, but in that case most of the CO2 is in the form of dissolved bicarbonate and calcium carbonate, obtained by partial decomposition of bicarbonate to CO2, is produced in low yield. A pH higher than 11 is also an option as it can affect the primary particle size and amorphous phase of the calcium carbonate.

[0020] The use of clean, content-controlled amorphous calcium carbonate (ACC) for a wide range of biomedical applications has already been demonstrated and reported in a series of patents and publications. If toxic metals present in calcium-based by-products were at or below ppm levels, the less clean ACC, but in very large quantities, could be utilized as an advantageous fertilizer and feedstock for animals such as chickens and cattle. If such ACC could be produced as a food supplement or drug at a fraction of the cost of currently used ACC, this would enhance and improve the quality of crops, fruits, and vegetables, as well as healthier livestock.

[0021] According to one aspect, the present invention provides a method for preparing a stabilized amorphous alkaline earth metal carbonate, the method comprising: (i) dissolving a base in an aqueous solution, the resulting solution having a pH of 8 or greater; (ii) bubbling or pressurizing CO2 gas into the solution obtained in step (i) followed by adding a salt of an alkaline earth metal; or adding an alkaline earth metal salt to the solution obtained in step (i), followed by bubbling or pressurizing CO2 gas through the solution, thereby precipitating an amorphous alkaline earth metal carbonate; (iii) recovering the resulting stabilized amorphous alkaline earth metal carbonate precipitate; The method includes adding at least one stabilizer in at least one of the following steps: (a) before bubbling or pressurizing the CO2 gas, (b) after bubbling or pressurizing the CO2 gas, (c) before adding the alkaline earth metal salt, (d) simultaneously with adding the alkaline earth metal salt, or (e) after adding the alkaline earth metal salt.

[0022] According to some embodiments, the stabilizer is added at the same time as adding the alkaline earth metal salt after bubbling or pressurizing the CO2 gas.

[0023] According to some embodiments, the method comprises: (i) dissolving a base in an aqueous solution, the resulting solution having a pH of 8 or greater; (ii) bubbling or pressurizing CO2 gas into the solution obtained in step (i), followed by adding an alkaline earth metal salt; (iii) recovering the resulting stabilized amorphous alkaline earth metal carbonate precipitate.

[0024] In some embodiments, the method includes adding a stabilizer before bubbling or pressurizing CO gas into the solution obtained in step (i). In some embodiments, the method includes adding a stabilizer after adding the alkaline earth metal salt. In some embodiments, the method includes adding a stabilizer before bubbling or pressurizing CO gas into the solution obtained in step (i) and after adding the alkaline earth metal salt.

[0025] According to some embodiments, the method comprises: (i) dissolving a base in an aqueous solution, the resulting solution having a pH of 8 or greater; (ii) adding an alkaline earth metal salt to the solution obtained in step (i), followed by bubbling or pressurizing CO2 gas through the solution; (iii) recovering the resulting stabilized amorphous alkaline earth metal carbonate precipitate.

[0026] According to some embodiments, the method includes adding a stabilizer simultaneously with adding the alkaline earth metal salt. According to some embodiments, the method includes adding a stabilizer prior to bubbling or pressurizing CO gas into the solution obtained in step (i). According to some embodiments, the method includes adding a stabilizer simultaneously with adding the alkaline earth metal salt and prior to bubbling or pressurizing CO gas.

[0027] According to some embodiments, the method comprises, as a first step, dissolving a base and a stabilizer in an aqueous solution. Thus, according to some embodiments, the present invention provides a method for preparing a stabilized alkaline earth metal carbonate, the method comprising: (i) dissolving a base and a stabilizer in an aqueous solution, the resulting solution having a pH of 8 or greater; (ii) bubbling or pressurizing CO2 gas through the solution obtained in step (i), followed by adding an alkaline earth metal salt and, optionally, adding a stabilizer to the solution; or adding an alkaline earth metal salt to the solution obtained in step (i), followed by bubbling or pressurizing CO2 gas through the solution and, optionally, adding a stabilizer; thereby precipitating a stabilized amorphous alkaline earth metal carbonate; (iii) optionally adding a stabilizer to the solution obtained in step (ii); (iv) recovering the resulting stabilized amorphous alkaline earth metal carbonate; The method provides a process wherein CO2 is constantly introduced into the solution during step (ii) and, if present, during step (iii), and wherein the stabilizers in step (i) and, if present, step (ii) and / or step (iii) are the same or different.

[0028] According to some embodiments, step (ii) comprises bubbling or pressurizing CO2 gas through the solution obtained in step (i), followed by adding a salt of an alkaline earth metal. Thus, according to some embodiments, the method comprises: (i) dissolving a base and a stabilizer in an aqueous solution; (ii) bubbling or pressurizing CO2 gas into the solution obtained in step (i), followed by adding an alkaline earth metal salt and, optionally, adding a stabilizer to the solution; (iii) optionally adding a stabilizer to the solution obtained in step (ii); (iv) recovering the resulting stabilized amorphous alkaline earth metal carbonate.

[0029] According to another embodiment, step (ii) comprises adding a salt of an alkaline earth metal to the solution obtained in step (i), followed by bubbling or pressurizing CO2 gas through the solution. Thus, according to some embodiments, the method comprises: (i) dissolving a base and a stabilizer in an aqueous solution; (ii) adding an alkaline earth metal salt to the solution obtained in step (i), and optionally adding a stabilizer to the solution obtained in step (i), followed by bubbling or pressurizing with CO gas; (iii) optionally adding a stabilizer to the solution obtained in step (ii); (iv) recovering the resulting stabilized amorphous alkaline earth metal carbonate.

[0030] According to some embodiments, the present invention provides a method for preparing a stabilized amorphous alkaline earth metal carbonate, the method comprising: (i) dissolving a base in an aqueous solution; (ii) a step of dissolving a stabilizer in the solution obtained in step (a) and bubbling or pressurizing CO2 gas, in which dissolution of the stabilizer and initiation of CO2 introduction by bubbling or pressurization are carried out in any order; (iii) adding a salt of an alkaline earth metal and optionally a stabilizer to the solution obtained in step (b), thereby precipitating a stabilized amorphous carbonate of the alkaline earth metal; (iv) optionally adding a stabilizer to the solution obtained in step (c); CO2 is constantly introduced into the solution during step (b) and, if CO2 is added, during step (c), and the stabilizers in steps (b) and (c) and / or (d) are the same or different.

[0031] According to some embodiments, the pH of the solution obtained after addition of base in step (i) is 8 or greater, 9 or greater, 10 or greater, 11 or greater, or 12 or greater. According to some embodiments, the pH of the solution obtained in step (i) is 9 or greater. According to some embodiments, the pH of the solution obtained in step (i) is 10 or greater. According to some embodiments, the pH of the solution obtained in step (i) is 11 or greater. According to some embodiments, the pH of the solution obtained in step (i) is 12 or greater. The term "pH equal to or above X" can be replaced with any one of the terms "pH equal to X," "pH of more than X," "pH higher than X," "pH of X or more," etc.

[0032] According to some embodiments, precipitation of the amorphous alkaline earth metal carbonate is achieved within 2 minutes.

[0033] According to some embodiments, the method includes adding a stabilizer in step (ii). Thus, according to some embodiments, step (ii) includes bubbling or pressurizing CO2 gas into the solution obtained in step (i), followed by adding an alkaline earth metal salt and adding a stabilizer. According to other embodiments, step (ii) includes adding an alkaline earth metal salt and a stabilizer to the solution obtained in step (i), followed by bubbling or pressurizing CO2 gas. According to some embodiments, the stabilizer added in steps (i) and (ii) is the same stabilizer. According to some embodiments, the stabilizers added in steps (i) and (ii) are different stabilizers.

[0034] According to some embodiments, the method includes adding a stabilizer only in steps (i) and (ii). According to some embodiments, the method includes adding a stabilizer in step (iii). According to some embodiments, the method includes adding a stabilizer only in steps (i) and (iii). According to some embodiments, the stabilizer added in steps (i) and (iii) is the same stabilizer. According to some embodiments, the stabilizer added in steps (i) and (iii) is different stabilizers. According to some embodiments, the method includes adding a stabilizer in steps (ii) and (iii). According to some embodiments, when a stabilizer is added in multiple steps, the stabilizer may be different in each step. According to other embodiments, the stabilizer in all steps may be the same stabilizer. In some examples, the method includes adding a stabilizer in step (iv). In some examples, the stabilizer in steps (ii), (iii), and (iv) is the same stabilizer. Similar methods may be used for other alkaline earth by-products. In an alternative process, the base and stabilizer can be (i) added to the alkaline earth metal solution or slurry, and then (ii) purged with CO to form the amorphous metal carbonate. The entire amount of stabilizer can be added to the solution at once before purging with CO. In other cases, the stabilizer can be added partially to the solution before purging and partially after purging.

[0035] In some instances, the process is carried out in batches. In other instances, the process may be carried out in a series of batch reactors. In some instances, the process may be carried out continuously. In this case, completion time is not a factor, but it is best to remove the formed product within a few minutes, preferably less than 10 minutes, less than 5 minutes, less than 3 minutes, or even less than 2 minutes.

[0036] According to some embodiments, the present invention provides a continuous method for preparing a stabilized amorphous alkaline earth metal carbonate, the method comprising: providing an aqueous solution having a pH of 8 or greater; (i) continuously adding a base, at least one stabilizer, and an alkaline earth metal to the aqueous solution; (ii) continuously bubbling or pressurizing CO gas through the solution; and (iii) continuously collecting the resulting amorphous alkaline earth metal carbonate precipitate, wherein the pH is maintained constant at 8 or greater during the entire process.

[0037] In some examples, the base is selected from an alkali metal hydroxide, ammonia, or ammonium hydroxide. In some embodiments, the base is sodium hydroxide. In other embodiments, the base is ammonium hydroxide.

[0038] In any one of the above and below embodiments, the alkaline earth metal salt is water-soluble. In some examples, the alkaline earth metal salt is selected from water-soluble halides, nitrates, and sulfates of the metal, and hydrates thereof. In some examples, the alkaline earth metal salt is selected from calcium chloride, calcium bromide, calcium nitrate, magnesium chloride, magnesium sulfate, magnesium nitrate, and combinations thereof. In one example, the alkaline earth metal salt is calcium chloride. In some examples, the alkaline earth metal salt is magnesium chloride. In another example, the alkaline earth metal salt is magnesium sulfate. In another embodiment, the alkaline earth metal salt is a combination of calcium chloride and magnesium sulfate. According to some embodiments, the method includes adding an alkaline earth metal salt and / or maintaining its concentration between 0.02 M and 0.1 M (molar, mol / L). According to some embodiments, the method includes adding CaCl and / or maintaining its concentration between 0.03 M and 0.8 M. According to some embodiments, the method includes adding MgSO4 and / or maintaining its concentration in the range of 0.04M to 1M.

[0039] In some examples, the stabilizer is selected from the group consisting of polyphosphates, inorganic polyphosphates, organic acids, phosphorylated amino acids, phosphorylated organic compounds, phosphonated organic compounds, sulfated or sulfonated organic compounds, phosphate or sulfate esters of hydroxycarboxylic acids, bisphosphonates, organic polyphosphates, polyphosphates, hydroxyl-containing organic compounds, derivatives thereof, proteins, any salts thereof, and any combinations thereof. In some examples, the stabilizer is selected from the group consisting of tripolyphosphate or a salt thereof, phosphoserine, citric acid, sodium triphosphate and citric acid, adenosine triphosphate, adenosine diphosphate, phytic acid, etidronic acid, pyrophosphate, polyphosphate, hexametaphosphate, ethanol, a salt thereof, and any combinations thereof. In some examples, the stabilizer is sodium tripolyphosphate. In some embodiments, the stabilizer is selected from triphosphate, pyrophosphate, hexametaphosphate, phytic acid, citric acid, and combinations thereof. According to one embodiment, the stabilizer is a combination of triphosphate and pyrophosphate, or a combination of triphosphate and hexametaphosphate, or a combination of triphosphate and phytic acid, or a combination of triphosphate and citric acid.

[0040] In some examples, the pH in step (i) is greater than 8, greater than 10, or greater than 12. In some examples, the pH in step (i) is 8-13, 8-12, 9-12, 9-11, 10-12, or 10-13.

[0041] In some examples, the pH is maintained at a value of 8 or greater, 9 or greater, 10 or greater, 11 or greater, or 12 or greater throughout the entire preparation process. In some examples, the pH is maintained at a value of 8-13, 8-12, 9-12, 9-11, 10-12, or 10-13 throughout the entire preparation process.

[0042] In some examples, the amount of base is at least 2 molar equivalents of the amount of alkaline earth metal salt. In some examples, the concentration of base is at least 2 molar equivalents of the concentration of alkaline earth metal salt. In some examples, the concentration of base is maintained at at least 2 molar equivalents of the concentration of alkaline earth metal salt.

[0043] The terms "at least X" and "X or more" mean a value greater than or equal to X. This term can be replaced with a phrase that limits an upper limit defined in an embodiment of this application.

[0044] In some examples, the total amount of stabilizer added is 2-15 wt% of the amount of alkaline earth metal salt. In some examples, the cumulative concentration of stabilizer added is 2-15 wt% of the concentration of alkaline earth metal salt. In some examples, the cumulative concentration of stabilizer added is kept constant at 2-15 wt% of the concentration of alkaline earth metal salt.

[0045] In some instances, the reaction is carried out at atmospheric pressure. In some instances, the reaction is carried out at a pressure of 1 to 60 bar.

[0046] In some instances, the reaction is carried out at ambient temperature.

[0047] In some instances, for example, precipitation of stabilized amorphous alkaline earth metal carbonates, e.g., ACC and AMC, in step (iii) is achieved within 2-3 minutes, optionally followed by addition of a stabilizer in step (iv).

[0048] According to some embodiments, the entire process of precipitation of stabilized amorphous alkaline earth metal carbonates, such as ACC and AMC, is accomplished within 2 minutes from the start of precipitation.

[0049] According to some embodiments, recovering the stabilized amorphous alkaline earth metal carbonate comprises filtering and / or drying the resulting amorphous alkaline earth metal carbonate precipitant.

[0050] In some examples, the present invention provides (i) dissolving a base and sodium tripolyphosphate as a stabilizer in an aqueous solution, the pH of the resulting aqueous solution being 8 or higher; (ii) bubbling or pressurizing CO2 into the solution obtained in step (i), followed by adding CaCl2 and, optionally, adding sodium tripolyphosphate as a stabilizer to the solution; (iii) optionally adding sodium tripolyphosphate as a stabilizer to the solution obtained in step (ii); (iv) recovering the resulting stabilized amorphous calcium carbonate, The method includes adding a stabilizer in step (iii). In some embodiments, the base is selected from NaOH and NH4OH and is added in an amount equal to at least 2 molar equivalents of CaCl2, and optionally, the CaCl2 is selected from anhydrous, monohydrate, and dihydrate CaCl2. In some embodiments, the method includes adding a stabilizer in step (iii). In some embodiments, the base is selected from NaOH or NH4OH and is added in an amount equal to 2 or 3 molar equivalents of CaCl2. According to some embodiments, the pH is maintained at a value of 8 or higher, 9 or higher, 10 or higher, 11 or higher, or 12 or higher throughout the entire preparation process. According to some embodiments, the pH is maintained at a value of 8 to 13 throughout the entire preparation process.

[0051] In some examples, the present invention provides (i) dissolving a base and sodium tripolyphosphate as a stabilizer in an aqueous solution, the pH of the resulting aqueous solution being 8 or higher; (ii) adding CaCl followed by bubbling or pressurizing with CO gas; (iii) optionally adding sodium tripolyphosphate as a stabilizer to the solution obtained in step (ii); (iv) recovering the resulting stabilized amorphous calcium carbonate, The method includes adding a stabilizer in step (iii). In some embodiments, the base is selected from NaOH and NH4OH and is added in an amount equal to at least 2 molar equivalents of CaCl2, and optionally, the CaCl2 is selected from anhydrous, monohydrate, or dihydrate CaCl2. In some embodiments, the method includes adding a stabilizer in step (iii). In some embodiments, the base is selected from NaOH or NH4OH and is added in an amount equal to 2 or 3 molar equivalents of CaCl2. According to some embodiments, the pH is maintained at a value of 8 or higher, 9 or higher, 10 or higher, 11 or higher, or 12 or higher throughout the entire preparation process. According to some embodiments, the pH is maintained at a value between 8 and 13 throughout the entire preparation process.

[0052] In some examples, the present invention provides (i) dissolving a base and sodium tripolyphosphate as a stabilizer in an aqueous solution, the pH of the resulting aqueous solution being 8 or higher; (ii) bubbling or pressurizing CO gas into the solution obtained in step (i), followed by adding MgSO to the solution; (iii) optionally adding sodium tripolyphosphate as a stabilizer to the solution obtained in step (ii); (iv) recovering the resulting stabilized amorphous magnesium carbonate; The method includes adding a stabilizer in step (iii). In some embodiments, the base is selected from NaOH and NH4OH and is added in an amount equal to at least 2 molar equivalents of MgSO4, and optionally, the MgSO4 is anhydrous or heptahydrate MgSO4. In some embodiments, the method includes adding a stabilizer in step (iii). In some embodiments, the base is selected from NaOH or NH4OH and is added in an amount equal to 2 or 3 molar equivalents of CaCl2 or MgSO4. According to some embodiments, the pH is maintained at a value of 8 or higher, 9 or higher, 10 or higher, 11 or higher, or 12 or higher throughout the entire preparation process. According to some embodiments, the pH is maintained at a value of 8 to 13 throughout the entire preparation process.

[0053] In some examples, the present invention provides (i) dissolving a base and sodium tripolyphosphate as a stabilizer in an aqueous solution, the pH of the resulting aqueous solution being 8 or higher; (ii) adding MgSO4 and optionally sodium tripolyphosphate as stabilizers to the solution obtained in step (i), followed by bubbling or pressurizing CO2 gas into the solution; (iii) optionally adding sodium tripolyphosphate as a stabilizer to the solution obtained in step (ii); (iv) recovering the resulting stabilized amorphous magnesium carbonate; The method includes adding a stabilizer in step (iii). In some embodiments, the base is selected from NaOH and NH4OH and is added in an amount equal to at least 2 molar equivalents of MgSO4, and optionally, the MgSO4 is anhydrous or heptahydrate MgSO4. In some embodiments, the method includes adding a stabilizer in step (iii). In some embodiments, the base is selected from NaOH or NH4OH and is added in an amount equal to 2 or 3 molar equivalents of MgSO4. According to some embodiments, the pH is maintained at a value of 8 or higher, 9 or higher, 10 or higher, 11 or higher, or 12 or higher throughout the entire preparation process. According to some embodiments, the pH is maintained at a value of 8 to 13 throughout the entire preparation process.

[0054] In some examples, the present invention provides a method comprising: providing an aqueous solution having a pH of 8 or greater; (i) continuously adding a base, sodium triphosphate, and calcium chloride to the aqueous solution; (ii) continuously bubbling or pressurizing CO gas through the solution; and (iii) continuously recovering the resulting amorphous calcium carbonate, wherein the base is selected from NaOH and NHOH and is added in an amount of at least 2 molar equivalents of calcium chloride; and the pH is maintained constant at 8 or greater throughout the entire process. According to some embodiments, the pH is maintained at a value of 8 or greater, 9 or greater, 10 or greater, 11 or greater, or 12 or greater throughout the entire preparation process. According to some embodiments, the pH is maintained at a value between 8 and 13 throughout the entire preparation process.

[0055] In some examples, the present invention provides a method comprising providing an aqueous solution having a pH of 8 or greater; (i) continuously adding a base, sodium triphosphate, and magnesium sulfate to the aqueous solution; (ii) continuously bubbling or pressurizing CO gas through the solution; and (iii) continuously recovering the resulting amorphous magnesium carbonate, wherein the base is selected from NaOH and NHOH and is added in an amount of at least 2 molar equivalents of magnesium sulfate, and the pH is maintained constant at 8 or greater throughout the entire process. According to some embodiments, the pH is maintained at a value of 8 or greater, 9 or greater, 10 or greater, 11 or greater, or 12 or greater throughout the entire preparation process. According to some embodiments, the pH is maintained at a value between 8 and 13 throughout the entire preparation process.

[0056] According to another aspect, the present invention provides a stabilized amorphous alkaline earth metal carbonate prepared by a method according to any one of the above examples. According to some examples, the present invention provides a stabilized amorphous calcium carbonate prepared by a method according to any one of the above examples. According to some examples, the present invention provides a stabilized amorphous magnesium carbonate prepared by a method according to any one of the above examples. According to some embodiments, the present invention provides a stabilized amorphous alkaline earth metal carbonate obtained or obtainable by a method according to any one of the above examples. According to some embodiments, the present invention provides a stabilized amorphous carbonate obtained or obtainable by a method according to any one of the above examples. According to another aspect, the present invention provides uses of the stabilized ACC prepared by the method of the present invention in agriculture and veterinary medicine. DETAILED DESCRIPTION OF THE INVENTION

[0057] According to one aspect, the present invention provides a method for preparing a stabilized alkaline earth metal carbonate, the method comprising: (i) dissolving a base in an aqueous solution, the resulting solution having a pH of 8 or greater; (ii) bubbling or pressurizing CO2 gas into the solution obtained in step (i) followed by adding a salt of an alkaline earth metal; or adding an alkaline earth metal salt to the solution obtained in step (i), followed by bubbling or pressurizing CO gas through the solution; thereby precipitating an amorphous alkaline earth metal carbonate; (iii) recovering the resulting stabilized amorphous alkaline earth metal carbonate precipitate; The method includes adding at least one stabilizer at at least one stage during the preparation process, non-limiting examples of which are (a) before bubbling or pressurizing CO2 gas, (b) after bubbling or pressurizing CO2 gas, (c) before adding an alkaline earth metal salt, (d) simultaneously with adding an alkaline earth metal salt, or (e) after adding an alkaline earth metal salt.

[0058] Thus, according to some embodiments, the present invention provides a method for preparing a stabilized amorphous alkaline earth metal carbonate, the method comprising: (i) dissolving a base in an aqueous solution, the resulting solution having a pH of 8 or greater; (ii) bubbling or pressurizing CO2 gas into the solution obtained in step (i) followed by adding a salt of an alkaline earth metal; or adding an alkaline earth metal salt to the solution obtained in step (i), followed by bubbling or pressurizing CO gas through the solution; thereby precipitating an amorphous alkaline earth metal carbonate; (iii) recovering the resulting amorphous alkaline earth metal carbonate precipitate; The method includes adding at least one stabilizer in at least one of the following steps: (a) before bubbling or pressurizing the CO2 gas, (b) after bubbling or pressurizing the CO2 gas, (c) before adding the alkaline earth metal salt, (d) simultaneously with adding the alkaline earth metal salt, or (e) after adding the alkaline earth metal salt.

[0059] The term "aqueous solution" refers to a composition that comprises at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or 100% water. In preferred embodiments, the term "aqueous solution" refers to "water," such as distilled water, double-distilled water, or any other aqueous solution known in the art.

[0060] According to some embodiments, the stabilizer is added before bubbling or pressurizing the CO2 gas. According to some embodiments, the stabilizer is added after bubbling or pressurizing the CO2 gas. According to some embodiments, the stabilizer is added before adding the alkaline earth metal salt. According to some embodiments, the stabilizer is added simultaneously with adding the alkaline earth metal salt, for example, by mixing the alkaline earth metal salt and the stabilizer together. According to some embodiments, the stabilizer is added after adding the alkaline earth metal salt. According to some embodiments, the stabilizer is added simultaneously with adding the alkaline earth metal salt before bubbling or pressurizing the CO2 gas. According to some embodiments, the stabilizer is added before bubbling or pressurizing the CO2 gas and after adding the alkaline earth metal salt. According to some embodiments, the stabilizer is added after bubbling or pressurizing the CO2 gas and after adding the alkaline earth metal salt.

[0061] According to some embodiments, the stabilizer is added at the same time as adding the alkaline earth metal salt after bubbling or pressurizing the CO2 gas.

[0062] According to some embodiments, the method comprises: (i) dissolving a base in an aqueous solution, the resulting solution having a pH of 8 or greater; (ii) bubbling or pressurizing CO2 gas into the solution obtained in step (i), followed by adding an alkaline earth metal salt; (iii) recovering the resulting amorphous alkaline earth metal carbonate precipitate.

[0063] In some embodiments, the method includes adding a stabilizer before bubbling or pressurizing CO gas into the solution obtained in step (i). In some embodiments, the method includes adding a stabilizer after adding the alkaline earth metal salt. In some embodiments, the method includes adding a stabilizer before bubbling or pressurizing CO gas into the solution obtained in step (i) and after adding the alkaline earth metal salt.

[0064] According to some embodiments, the method comprises: (i) dissolving a base in an aqueous solution, the resulting solution having a pH of 8 or greater; (ii) adding an alkaline earth metal salt to the solution obtained in step (i), followed by bubbling or pressurizing CO gas through the solution; (iii) recovering the resulting amorphous alkaline earth metal carbonate precipitate.

[0065] According to some embodiments, the method includes adding a stabilizer simultaneously with adding the alkaline earth metal salt. According to some embodiments, the method includes adding a stabilizer prior to bubbling or pressurizing CO gas into the solution obtained in step (i). According to some embodiments, the method includes adding a stabilizer simultaneously with adding the alkaline earth metal salt and prior to bubbling or pressurizing CO gas.

[0066] According to some embodiments, the stabilizers added in the different stages may be the same or different. According to some embodiments, the stabilizer added before bubbling or pressurizing CO gas into the solution obtained in step (i) and the stabilizer added after adding the alkaline earth metal salt are the same stabilizer. According to other embodiments, the stabilizers added in the different stages are different stabilizers.

[0067] According to some embodiments, the stabilizer is added at the same time as the alkaline earth metal salt is added, and the same stabilizer is added before bubbling or pressurizing the CO gas. According to other embodiments, the stabilizers added at different stages are different stabilizers.

[0068] As contemplated by the present invention, the terms "bubbling CO" and "pressurizing CO" may be used interchangeably and refer to incorporating CO into an aqueous solution. This process may be carried out as known in the art. Bubbling may be carried out at a constant pressure or at a varying pressure, at a constant pace or at a varying pace.

[0069] According to some embodiments, the method comprises, as a first step, dissolving a base and a stabilizer in an aqueous solution. Thus, according to some embodiments, the present invention provides a method for preparing a stabilized amorphous alkaline earth metal carbonate, the method comprising: (i) dissolving a base and a stabilizer in an aqueous solution, the resulting solution having a pH of 8 or greater; (ii) bubbling or pressurizing CO2 gas through the solution obtained in step (i), followed by adding an alkaline earth metal salt and, optionally, adding a stabilizer to the solution, or adding an alkaline earth metal salt to the solution obtained in step (i), followed by bubbling or pressurizing CO2 gas through the solution and, optionally, adding a stabilizer; thereby precipitating a stabilized amorphous alkaline earth metal carbonate; (iii) optionally adding a stabilizer to the solution obtained in step (ii); (iv) recovering the resulting stabilized amorphous alkaline earth metal carbonate; CO2 is constantly introduced into the solution during step (ii) and, if present, during step (iii), and the stabilizers in step (i) and, if present, step (ii) and / or step (iii) are the same or different.

[0070] According to some embodiments, step (ii) comprises bubbling or pressurizing CO2 gas through the solution obtained in step (i), followed by adding a salt of an alkaline earth metal. Thus, according to some embodiments, the method comprises: (i) dissolving a base and a stabilizer in an aqueous solution; (ii) bubbling or pressurizing CO2 gas into the solution obtained in step (i), followed by adding an alkaline earth metal salt and, optionally, adding a stabilizer to the solution; (iii) optionally adding a stabilizer to the solution obtained in step (ii); (iv) recovering the resulting stabilized amorphous alkaline earth metal carbonate.

[0071] According to another embodiment, step (ii) comprises adding a salt of an alkaline earth metal to the solution obtained in step (i), followed by bubbling or pressurizing CO2 gas through the solution. Thus, according to some embodiments, the method comprises: (i) dissolving a base and a stabilizer in an aqueous solution; (ii) adding an alkaline earth metal salt to the solution obtained in step (i), and optionally adding a stabilizer to the solution obtained in step (i), followed by bubbling or pressurizing with CO gas; (iii) optionally adding a stabilizer to the solution obtained in step (ii); (iv) recovering the resulting stabilized amorphous alkaline earth metal carbonate.

[0072] In some embodiments, the present invention provides a method for preparing a stabilized amorphous carbonate of an alkaline earth metal, the method comprising: (a) dissolving a base in an aqueous solution; (b) dissolving a stabilizer in the solution obtained in step (a) and then bubbling or pressurizing CO2 gas into the solution, in which dissolution of the stabilizer and initiation of CO2 introduction by bubbling or pressurization are performed in either order; (c) adding an alkaline earth metal salt and optionally a stabilizer to the solution obtained in step (b), thereby precipitating ACC; (d) optionally adding a stabilizer to the solution obtained in step (c); CO2 is constantly introduced into the solution during step (b) and, if CO2 is added, during step (c), and the stabilizers in steps (b) and (c) and step (d) are the same or different.

[0073] According to some embodiments, the method of the present invention allows for the fixation of CO2 gas. Therefore, in any one of the embodiments of the present invention, the term "method of preparing a stabilized amorphous carbonate of an alkaline earth metal" can be replaced with the term "a method of fixating CO2."

[0074] According to some embodiments, the present invention provides a method for fixing CO2, the method comprising: (a) dissolving a base in an aqueous solution; (b) dissolving a stabilizer in the solution obtained in step (a) and then bubbling or pressurizing CO2 gas into the solution, in which dissolution of the stabilizer and initiation of CO2 introduction by bubbling or pressurization are performed in either order; (c) adding an alkaline earth metal salt and optionally a stabilizer to the solution obtained in step (b), thereby precipitating a stabilized amorphous alkaline earth metal carbonate; (d) optionally adding a stabilizer to the solution obtained in step (c); CO2 is constantly introduced into the solution during step (b) and, if CO2 is added, during step (c), and the stabilizers in steps (b) and (c) and step (d) are the same or different.

[0075] According to some embodiments, the present invention provides a method for fixing CO2, the method comprising: (i) dissolving a base and a stabilizer in an aqueous solution, the resulting solution having a pH of 8 or greater; (ii) bubbling or pressurizing CO2 gas through the solution obtained in step (i), followed by adding an alkaline earth metal salt and, optionally, adding a stabilizer to the solution, or adding an alkaline earth metal salt to the solution obtained in step (i), followed by bubbling or pressurizing CO2 gas through the solution and, optionally, adding a stabilizer; thereby fixing CO2 and precipitating stabilized alkaline earth metal carbonates; (iii) optionally adding a stabilizer to the solution obtained in step (ii); (iv) recovering the resulting stabilized amorphous alkaline earth metal carbonate; CO2 is constantly introduced into the solution during step (ii) and, if present, during step (iii), and the stabilizers in step (i) and, if present, step (ii) and / or step (iii) are the same or different.

[0076] According to some embodiments, the pH of the solution obtained after the addition of the base in step (i) is 8 or higher, 9 or higher, 10 or higher, 11 or higher, or 12 or higher. According to some embodiments, the pH of the solution obtained in step (i) is 9 or higher. According to some embodiments, the pH of the solution obtained in step (i) is 10 or higher. According to some embodiments, the pH of the solution obtained in step (i) is 11 or higher. According to some embodiments, the pH of the solution obtained in step (i) is 12 or higher. According to some embodiments, the pH of the solution obtained in step (i) is 8 to 13. According to some embodiments, the pH of the solution obtained in step (i) is 9 to 13. According to some embodiments, the pH of the solution obtained in step (i) is 10 to 13. According to some embodiments, the pH of the solution obtained in step (i) is 1 to 13. According to some embodiments, the pH of the solution obtained in step (i) is 8 to 12. According to some embodiments, the pH of the solution obtained in step (i) is 9 to 12. According to some embodiments, the pH of the solution obtained in step (i) is 10 to 12. According to some embodiments, the pH of the solution obtained in step (i) is 9 to 11. According to some embodiments, the pH of the solution obtained in step (i) is 10 to 12. According to some embodiments, the pH of the solution obtained in step (i) is 9.5 to 10.5 or about 10.

[0077] According to some embodiments, precipitation of the alkaline earth metal carbonate is achieved within 2 minutes. According to some embodiments, precipitation of the alkaline earth metal carbonate is achieved within 3 minutes. According to some embodiments, precipitation of the alkaline earth metal carbonate is achieved within 1.5 minutes.

[0078] According to some embodiments, the method includes adding a stabilizer in step (ii). Thus, according to some embodiments, step (ii) includes bubbling or pressurizing CO2 gas into the solution obtained in step (i), followed by adding an alkaline earth metal salt and adding a stabilizer. According to other embodiments, step (ii) includes adding an alkaline earth metal salt and a stabilizer to the solution obtained in step (i), followed by bubbling or pressurizing CO2 gas. According to some embodiments, the stabilizer added in steps (i) and (ii) is the same stabilizer. According to some embodiments, the stabilizers added in steps (i) and (ii) are different stabilizers.

[0079] According to some embodiments, the method comprises adding a stabilizer only in steps (i) and (ii). According to some embodiments, the method comprises adding a stabilizer in step (iii). According to some embodiments, the method comprises adding a stabilizer only in steps (i) and (iii). According to some embodiments, the stabilizer added in steps (i) and (iii) is the same stabilizer. According to some embodiments, the stabilizer added in steps (i) and (iii) is different stabilizers. According to some embodiments, the method comprises adding a stabilizer in steps (ii) and (iii). According to some embodiments, when a stabilizer is added in multiple stages or steps, the stabilizer may be different in each step. According to other embodiments, the stabilizer in all steps may be the same stabilizer.

[0080] According to any one of the above embodiments, the method may include a step of degassing the aqueous solution before the start of the process of preparing the stabilized amorphous alkaline earth metal carbonate or fixing CO. Degassing may be performed using any known technique. According to some embodiments, degassing is performed, for example, by bubbling CO gas through the aqueous solution before adding the base.

[0081] According to some embodiments, the method of the present invention is carried out / performed in the form of a batch reaction. According to some embodiments, the method is carried out / performed in the form of a series of batches. Thus, according to any one of the above embodiments, the method is a batch method.

[0082] According to some embodiments, the method is carried out in the form of a continuous process. Thus, according to some embodiments, the present invention provides a method for preparing a stabilized amorphous alkaline earth metal carbonate, the method comprising: providing an aqueous solution having a pH of 8 or greater; (i) continuously adding a base, at least one stabilizer, and an alkaline earth metal to the aqueous solution; (ii) continuously bubbling or pressurizing CO2 gas through the solution; and (iii) continuously collecting the resulting stabilized amorphous alkaline earth metal carbonate precipitate, wherein the pH is maintained constant at 8 or greater throughout the process. According to some embodiments, the pH of the provided solution is 8 or greater, 9 or greater, 10 or greater, 11 or greater, or 12 or greater, and is maintained at a value between 8 and 12 throughout the process. According to some embodiments, the pH of the provided solution is 8 to 13, and the pH is maintained at a value between 8 and 13 throughout the process. According to some embodiments, the pH of the provided solution is 8 to 13. According to some embodiments, the pH of the provided solution is 9 to 13. According to some embodiments, the pH of the provided solution is between 10 and 13. According to some embodiments, the pH of the provided solution is between 1 and 13. According to some embodiments, the pH of the provided solution is between 8 and 12. According to some embodiments, the pH of the provided solution is between 9 and 12. According to some embodiments, the pH of the provided solution is between 10 and 12. According to some embodiments, the pH of the provided solution is between 9 and 11. According to some embodiments, the pH of the provided solution is between 10 and 12. According to some embodiments, the pH of the provided solution is between 9.5 and 10.5, or about 10. According to some embodiments, the pH is maintained at a value between 8 and 13 throughout the entire process. According to some embodiments, the pH is maintained at a value between 9 and 13 throughout the entire process. According to some embodiments, the pH is maintained at a value between 10 and 13 throughout the entire process. According to some embodiments, the pH is maintained at a value between 1 and 13 throughout the entire process. According to some embodiments, the pH is maintained at a value between 8 and 12 throughout the entire process. According to some embodiments, the pH is maintained at a value between 9 and 12 during the entire process.According to some embodiments, the pH is maintained at a value of 10-12 during the entire process. According to some embodiments, the pH is maintained at a value of 9-11 during the entire process. According to some embodiments, the pH is maintained at a value of 10-12 during the entire process. According to some embodiments, the pH is maintained at a value of 9.5-10.5 or about 10 during the entire process.

[0083] The term "amorphous alkaline earth metal carbonate" refers to an amorphous form of any alkaline earth metal carbonate. Non-limiting examples of alkaline earth metals are calcium and magnesium. The terms "amorphous alkaline earth metal carbonate" and "stabilized amorphous alkaline earth metal carbonate" are used interchangeably herein. The terms "amorphous calcium carbonate," "amorphous calcium carbonate," "stable ACC," and "stabilized ACC" are used interchangeably herein and refer to amorphous forms of calcium carbonate. The terms "amorphous magnesium carbonate," "amorphous magnesium carbonate," "stable AMC," and "stabilized AMC" are used interchangeably herein and refer to amorphous forms of magnesium calcium carbonate. The term AMC does not exclude the presence of Mg-OH functional groups. As used herein, the term "stable" indicates that the calcium carbonate remains in an amorphous form for an extended period of time, for example, for at least about 7 days in a solid form having about 30% or less crystalline calcium carbonate. According to any one of the above embodiments, the composition is stable for at least 7 days. According to some embodiments, the composition is stable for at least 1 month. According to other embodiments, the composition is stable for at least 3 months. According to further embodiments, the composition is stable for 6 months. According to certain embodiments, the composition is stable for at least 1 year. According to certain embodiments, the composition is stable for at least 2 years.According to some embodiments, the ACC is stable in amorphous form in aqueous solution for at least 7 days, at least 1 month, at least 3 months, or 6 months.

[0084] In most cases, the resulting ACC or AMC contains 1-20% by weight of adsorbed water and maintains its stability even in the presence of stabilizers and under dry conditions for further storage. According to some embodiments, the resulting ACC contains 5-15% by weight or about 10% by weight of adsorbed water. As can be seen from the examples, the ACC powders obtained in the examples contained about 6-10% by weight of water at the time of formulation. Regarding calcium content, this means that the calcium content of the ACC is within a practical range of 28-38% by weight of its composition. According to some embodiments, the resulting stabilized ACC contains 30-38%, 32-36%, or about 34% by weight of calcium.

[0085] Minor precursors to water are bicarbonate [Ca-O-(C=O)--OH] and carbonate anions [Ca-O-(C=O)--O] found in the disordered molecular network of ACC. - At high temperatures, as part of the crystallization process, these species are converted to fully bound carbonates by a condensation reaction, which results in the release of a water molecule.

[0086] In the case of amorphous magnesium carbonate, even more complex presence of water and water precursors can be expected, since the molecular structures of most of the eight defined phases of crystalline magnesium carbonate are known to be "hydrate" (i.e., containing water molecules complexed by strong bonds to the Mg element), "basic" (i.e., containing Mg-OH), or both. Furthermore, the crystallized magnesium carbonate phases, e.g., previously known as MgCO3 . The presence of various bicarbonate species has been detected in the nesquehonite phase, the most common of which was previously defined as 3H2O.

[0087] According to some embodiments, the alkaline earth metal salt is a water-soluble salt of an alkaline earth metal. According to some embodiments, the alkaline earth metal salt is selected from metal halides, nitrates, and sulfates, and hydrates thereof. According to some embodiments, the alkaline earth metal is selected from calcium and magnesium. According to some embodiments, the alkaline earth metal salt is selected from calcium halides, magnesium halides, calcium nitrate, magnesium nitrate, and magnesium sulfate. According to some embodiments, the halide is selected from chloride and bromide. According to some embodiments, the alkaline earth metal salt is selected from calcium chloride, calcium bromide, calcium nitrate, magnesium chloride, magnesium sulfate, magnesium nitrate, and combinations thereof. According to some embodiments, the alkaline earth metal salt is calcium chloride. According to some embodiments, the alkaline earth metal salt is calcium sulfate. According to some embodiments, the alkaline earth metal salt is magnesium chloride. According to some embodiments, the alkaline earth metal salt is magnesium sulfate. According to some embodiments, the alkaline earth metal salt can be water insoluble, such as CaO, Ca(OH), MgO, Mg(OH), etc. In another embodiment, the alkaline earth metal salt is a combination of calcium chloride and magnesium sulfate.

[0088] According to some embodiments, the alkaline earth metal salt is calcium chloride. According to some embodiments, calcium chloride can be in any known hydration state, i.e., CaCl·nH0, e.g., anhydrous, monohydrate, or dihydrate, for various values ​​of n=0, 1, 2, 4, or 6. According to some embodiments, calcium chloride is calcium chloride hydrate.

[0089] According to some embodiments, the alkaline earth metal salt is magnesium sulfate. According to some embodiments, the magnesium sulfate can be in any known hydration state. The magnesium sulfate can be in the form of a hydrate, MgSO4·nH2O, for various values ​​of n from 1 to 11. According to some embodiments, the magnesium sulfate can be in the form of an anhydrous or heptahydrate. According to some embodiments, the magnesium sulfate is magnesium sulfate heptahydrate.

[0090] According to some embodiments, the method comprises adding 0.02 to 1 molar (M) alkaline earth metal salt. According to some embodiments, the method comprises adding 0.02 to 0.95 M alkaline earth metal salt. According to some embodiments, the method comprises adding 0.03 to 0.9 M alkaline earth metal salt. According to some embodiments, the method comprises adding 0.06 to 0.86 M alkaline earth metal salt. According to some embodiments, the method comprises adding 0.1 to 0.85 M alkaline earth metal salt. According to some embodiments, the method comprises adding 0.15 to 0.85 M alkaline earth metal salt. According to some embodiments, the method comprises adding 0.2 to 0.85 M alkaline earth metal salt. According to some embodiments, the method comprises adding 0.25 to 0.85 M alkaline earth metal salt. According to some embodiments, the method comprises adding 0.3 to 0.80 M alkaline earth metal salt. According to some embodiments, the method comprises adding 0.34-0.85M alkaline earth metal salt. According to some embodiments, the method comprises adding 0.2-0.6M alkaline earth metal salt. According to some embodiments, the method comprises adding 0.3-0.5M alkaline earth metal salt. According to some embodiments, the method comprises adding 0.3-0.4M alkaline earth metal salt. According to some embodiments, the alkaline earth metal salt is calcium chloride. According to some embodiments, the alkaline earth metal salt is magnesium sulfate.

[0091] According to some embodiments, the method comprises adding 0.1-0.85M calcium chloride. According to some embodiments, the method comprises adding 0.2-0.85M calcium chloride. According to some embodiments, the method comprises adding 0.3-0.8M calcium chloride. According to some embodiments, the method comprises adding 0.3-0.7M calcium chloride. According to some embodiments, the method comprises adding 0.3-0.6M calcium chloride. According to some embodiments, the method comprises adding 0.3-0.5M calcium chloride. According to some embodiments, the method comprises adding about 0.34M calcium chloride. According to some embodiments, the calcium chloride can be in any known hydration state, for example, anhydrous, monohydrate, or dihydrate.

[0092] According to some embodiments, the method comprises adding 0.1-0.85M magnesium sulfate. According to some embodiments, the method comprises adding 0.2-1M magnesium sulfate. According to some embodiments, the method comprises adding 0.3-0.9M magnesium sulfate. According to some embodiments, the method comprises adding 0.35-0.8M magnesium sulfate. According to some embodiments, the method comprises adding 0.4-0.6M magnesium sulfate. According to some embodiments, the method comprises adding 0.4-0.5M magnesium sulfate. According to some embodiments, the method comprises adding about 0.46M magnesium sulfate. According to some embodiments, the magnesium sulfate can be in the form of anhydrous or heptahydrate. According to some embodiments, the magnesium sulfate is magnesium sulfate heptahydrate.

[0093] According to any one of the above embodiments, when referring to a continuous method of preparing an amorphous stabilized amorphous alkaline earth metal carbonate, the term "adding a compound at a concentration X" or any equivalent of this phrase contemplates continuous addition and maintaining the stated concentration.

[0094] According to some embodiments, the base is selected from an alkali metal hydroxide, ammonia, or ammonium hydroxide. According to some embodiments, the base is an alkali metal hydroxide. According to some embodiments, the alkali metal is selected from sodium and potassium. According to one embodiment, the alkali metal hydroxide is sodium hydroxide (NaOH). According to one embodiment, the base is ammonia. According to one embodiment, the base is ammonium hydroxide.

[0095] According to some embodiments, the amount of base added in step (i) corresponds to at least 2 molar equivalents of the amount of alkaline earth metal salt. According to some embodiments, the amount of base added in step (i) corresponds to at least 3 molar equivalents of the amount of alkaline earth metal salt. According to some embodiments, the amount of base, such as NaOH, ammonia, or ammonium hydroxide, corresponds to at least 2 molar equivalents or at least 3 molar equivalents of the alkaline earth metal added to the reaction. According to some embodiments, the concentration of the base, e.g., NaOH or ammonium hydroxide, is 2, 2.5, 3, 3.5, 4, 4.5, or 5 molar equivalents of the alkaline earth metal added to the reaction. According to some embodiments, the concentration of the alkaline earth metal base, between 2 and 5 molar equivalents, is maintained constant by constantly adding base to the reaction mixture.

[0096] According to some embodiments, the amount / concentration of NaOH added in step (i) corresponds to at least 2 molar equivalents or at least 3 molar equivalents of added CaCl. According to some embodiments, the amount / concentration of NH4OH added in step (i) corresponds to at least 2 molar equivalents or at least 3 molar equivalents of added CaCl.

[0097] According to some embodiments, the amount / concentration of NaOH in step (i) corresponds to at least 2 molar equivalents or at least 3 molar equivalents of the added MgSO. According to some embodiments, the amount / concentration of NHOH in step (i) corresponds to at least 2 molar equivalents or at least 3 molar equivalents of the added MgSO. According to some embodiments, the base is added continuously or in portions throughout the process via solid, solution, or gas phase. According to some embodiments, the concentration of the base, e.g., NaOH or NHOH, is kept constant and corresponds to at least 2 molar equivalents of the alkaline earth metal salt, e.g., CaCl or MgSO.

[0098] According to any one of the above embodiments, the ACC is stabilized by at least one stabilizer. The terms "stabilizing agent" and "stabilizer" are used interchangeably herein and refer to any molecule, ion, or substance that contributes to preserving calcium carbonate in an amorphous state during the manufacture, formulation, and / or storage of the ACC. According to the teachings of the present invention, the ACC acts as an active agent that provides improved exercise and muscle performance. According to the teachings of the present invention, any ACC that remains stable can be used. Any compound that can stabilize ACC in its amorphous form is suitable for the practice of the present invention.

[0099] ACC stabilizer The stabilizer may include, but is not limited to, molecules having one or more functional groups selected from hydroxyl, carboxyl, ester, amine, phosphino, phosphono, phosphate, sulfonyl, sulfate, or sulfino groups. The hydroxy-containing compound in combination with the hydroxide optionally also has other functional groups, such as carboxyl, but the hydroxyl is not esterified.

[0100] According to some embodiments, the stabilizer has low or no toxicity to mammalian cells or organisms, particularly humans. According to some embodiments, the stabilizer is food, dietary supplement, or pharmaceutical grade.

[0101] In certain embodiments, the ACC stabilizer is, independently at each occurrence, an organic acid, a phosphorylated, phosphonated, sulfated, or sulfonated organic compound, a phosphoric or sulfate ester of a hydroxyl carboxylic acid, an organic amine compound, a hydroxyl-containing organic compound, an organic phosphorus compound or a salt thereof, a phosphorylated amino acid and its derivatives, a bisphosphonate compound, an organic phosphate compound, an organic phosphonate compound, an inorganic phosphoric acid, an organic compound with multiple functional groups as defined above, an inorganic phosphate and polyphosphate compound, a polyphosphate chain, an organic surfactant, an organic compound having a bioessential inorganic ion, a salt thereof, or any combination thereof.

[0102] According to some embodiments, the stabilizer is an organic acid or a salt thereof. According to certain embodiments, the organic acid is selected from ascorbic acid, citric acid, lactic acid, acetic acid, oxalic acid, malonic acid, glutaconic acid, succinic acid, maleic acid, lactic acid, aconitic acid, or a salt thereof, optionally containing at least two carboxyl groups and a molecular weight of 250 g / mol or less, such as citric acid, tartaric acid, malic acid, etc. According to one particular embodiment, the stabilizer is citric acid or a citrate salt.

[0103] In another embodiment, the phosphate ester of a hydroxyl carboxylic acid is phosphoenolpyruvic acid. In another embodiment, the phosphate or sulfate ester of a hydroxyl carboxylic acid comprises an amino acid. Examples of such esters are phosphoserine, phosphothreonine, sulfoserine, sulfothreonine, and phosphocreatine.

[0104] The hydroxyl-containing compounds combined with the hydroxides can include, for example, mono-, di-, tri-, oligo-, and polysaccharides such as sucrose or other polyols such as glycerol. The hydroxyl-containing compounds can further include hydroxy acids such as citric acid, tartaric acid, malic acid, etc., or hydroxyl-containing amino acids such as serine or threonine and their salts. Each possibility represents a separate embodiment of the present invention.

[0105] Some specific, non-limiting examples of such ACC stabilizers include phytic acid, citric acid and their salts, sodium pyrophosphate dibasic, adenosine 5'-monophosphate (AMP) sodium salt, adenosine 5'-diphosphate (ADP) sodium salt and adenosine 5'-triphosphate (ATP) disodium salt hydrate, phosphoserine, phosphorylated amino acids, food-grade surfactants, sodium stearoyl lactylate, and combinations thereof.

[0106] According to some embodiments, the stabilizer comprises at least one component selected from phosphate or sulfate esters of hydroxyl carboxylic acids, such as phosphoenolpyruvate, phosphoserine, phosphothreonine, sulfoserine, or sulfothreonine, and a hydroxyl-containing organic compound selected from mono-, di-, tri-, oligo-, and polysaccharides, e.g., sucrose, mannose, glucose.

[0107] The hydroxyl-containing compound may further comprise at least one alkali hydroxide, such as sodium hydroxide or potassium hydroxide. Phosphorylated acids may be present in oligopeptides and polypeptides. In other embodiments of the present invention, the stabilizer is an organic acid selected from monocarboxylic or multicarboxylic acids, for example, dicarboxylic or tricarboxylic acids. Each possibility represents a separate embodiment of the present invention. The organic acid may be as defined above.

[0108] In some embodiments of the present invention, the ACC stabilizer is selected from a phosphorylated amino acid, a polyol, and a combination thereof. In some embodiments, the stable ACC comprises a phosphorylated compound as a stabilizer, where the phosphorylation is performed on the hydroxyl group of an organic compound. In some embodiments, the stable ACC comprises a stabilizer selected from the group consisting of citric acid, phosphoserine, phosphothreonine, and a combination thereof. Non-limiting examples of stabilizers containing phosphate, phosphite, phosphonate groups and their salts or esters include phytic acid, dimethyl phosphate, trimethyl phosphate, sodium pyrophosphate, tetraethyl pyrophosphate, ribulose bisphosphate, etidronic acid and other medical bisphosphonates, 3-phosphoglyceric acid, glyceraldehyde 3-phosphate, 1-deoxy-D-xylulose-5-phosphate sodium salt, diethylenetriaminepentakis(methylphosphonic acid), nitrilotri(methylphosphonic acid), 5-phospho-D-ribose 1-diphosphate pentasodium salt, adenosine 5'-diphosphate sodium salt, adenosine 5'-triphosphate disodium salt hydrate, Examples of suitable phosphate buffers include α-D-galactosamine 1-phosphate, 2-phospho-L-ascorbic acid trisodium salt, α-D-galactose 1-phosphate dipotassium salt pentahydrate, α-D-galactosamine 1-phosphate, O-phosphorylethanolamine, disodium salt hydrate, 2,3-diphospho-D-glyceric acid pentasodium salt, phospho(enol)pyruvic acid monosodium salt hydrate, D-glyceraldehyde 3-phosphate, sn-glycerol 3-phosphate lithium salt, D-(-)-3-phosphoglyceric acid disodium salt, D-glucose 6-phosphate sodium salt, phosphatidic acid, ibandronate sodium salt, phosphonoacetic acid, DL-2-amino-3-phosphonopropionic acid, or combinations thereof.

[0109] In some embodiments, the stabilizer may be a bioessential inorganic ion, including, inter alia, Na, K, Mg, Zn, Fe, P, S, N, P, or S in the oxide phase, or N as an ammonia or nitro group.

[0110] The stabilized ACC may be stabilized by two or more stabilizers, for example, two, three, or more stabilizers. The stabilizers may be added during the synthesis and precipitation of the ACC primary particles and are defined as "internal stabilizers." The stabilizers may be added after synthesis and attached to the outer surface of the particles and are defined as "external stabilizers." In some embodiments in which both internal and external stabilizers are used, the internal and external stabilizers are similar. In other embodiments, the internal and external stabilizers are different stabilizers. The internal and external stabilizers may be independent of each other, as defined above, or each may be a combination of multiple types of stabilizers.

[0111] A stable ACC can contain three or more stabilizers, one or more of which are added to the ACC during its formation and precipitation.

[0112] According to some embodiments, the stabilizer is selected from the group consisting of polyphosphates, polyphosphonates, bisphosphonates, phosphorylated amino acids, citric acid, salts thereof, and any combination thereof. In some embodiments, more than one stabilizer is added, for example, two, three, or four stabilizers.

[0113] According to one embodiment, ACC is stabilized by a combination of phosphoserine and citrate. According to another embodiment, ACC is stabilized by a combination of triphosphate and citrate.

[0114] According to some embodiments, the stabilizer is a polyphosphate or a pharmaceutically acceptable salt thereof. According to some embodiments, the polypolyphosphate is a physiologically compatible, water-soluble polypolyphosphate selected from the group consisting of sodium, potassium, and any other essential cation of polyphosphate. In one embodiment, the polyphosphate is an organic or inorganic polyphosphate. As used herein, the term "polyphosphate" refers to (1) a polymeric anhydride of PO or (2) a phosphorylated organic compound containing two or more phosphorylated groups via a C-P (ether) bond. An example of a type 2 polyphosphate is phytic acid or its salt, which contains six phosphorylated groups. According to some embodiments, the polypolyphosphate is a physiologically compatible, water-soluble polyphosphate selected from the group consisting of sodium polyphosphate and potassium polyphosphate. In some embodiments, the polyphosphate is an inorganic polyphosphate or a pharmaceutically acceptable salt thereof. Non-limiting examples of such salts are Na, K, Mg, Mn, and Zn. The polyphosphate, such as inorganic polyphosphate, contains 2 to 10 phosphate groups, e.g., 2, 3, 4, 5, 6, 7, 8, 9, or 10 phosphate groups. According to some embodiments, the inorganic polyphosphate is selected from pyrophosphate, triphosphate, and hexametaphosphate. According to one embodiment, the stabilizer is polyphosphate or a pharmaceutically acceptable salt thereof, such as sodium pyrophosphate. According to another embodiment, the stabilizer is triphosphate (tripolyphosphate) or a pharmaceutically acceptable salt thereof, such as sodium triphosphate. The terms "triphosphate" and "tripolyphosphate" are used interchangeably herein. According to further embodiments, the stabilizer is hexametaphosphate or a pharmaceutically acceptable salt thereof, such as sodium hexametaphosphate.

[0115] According to some embodiments, the stabilizer is a polyphosphonate, such as a bisphosphonate or a tetraphosphonate, or a pharmaceutically acceptable salt thereof. Non-limiting examples of salts are Na, K, Mg, Mn, and Zn.

[0116] The term "bisphosphonate," as used herein, refers to an organic compound having two phosphonate (PO(OH)) groups. This term further relates to compounds having a PO-organo-PO backbone. Most typically, there is a series of bisphosphonates used as pharmaceuticals to treat osteoporosis. According to some embodiments, the bisphosphonate is selected from the group consisting of etidronic acid, zoledronic acid, medronic acid, alendronic acid, and pharmaceutically acceptable salts thereof. According to some embodiments, the stabilizer is etidronic acid or a pharmaceutically acceptable salt thereof. According to another embodiment, the stabilizer is zoledronic acid or a pharmaceutically acceptable salt thereof. According to further embodiments, the stabilizer is medronic acid or a pharmaceutically acceptable salt thereof. According to certain embodiments, the stabilizer is alendronic acid or a pharmaceutically acceptable salt thereof.

[0117] In certain embodiments, the stabilizer is a phosphorylated amino acid. In one embodiment, the phosphorylated amino acid is phosphoserine. In another embodiment, the phosphorylated amino acid is phosphothreonine.

[0118] According to a particular embodiment, the stabilizer is phytic acid or a salt thereof.

[0119] According to some embodiments, the ACC composition comprises a combination of the stabilizers disclosed above.

[0120] According to some embodiments, the stabilizer is an inorganic polyphosphate or bisphosphonate as defined above, and the molar ratio between the P atoms of the stabilizer and the Ca atoms of the ACC (P:Ca molar ratio) is about 1:90 to 1:1. In one embodiment, the P:Ca molar ratio is about 1:40 to about 1:1. In a further embodiment, the P:Ca molar ratio is about 1:35 to about 1:2. In certain embodiments, the P:Ca molar ratio is about 1:30 to about 1:3. In certain embodiments, the P:Ca molar ratio is about 1:28 to about 1:3. In other embodiments, the P:Ca molar ratio is about 1:25 to about 1:4. In still further embodiments, the P:Ca molar ratio is about 1:20 to about 1:5. In another embodiment, the P:Ca molar ratio is about 1:20 to about 1:6. In certain embodiments, the P:Ca molar ratio is about 1:15 to about 1:5. In another specific embodiment, the P:Ca molar ratio is about 1:25 to about 1:5. According to some embodiments, the inorganic polyphosphate is pyrophosphate, triphosphate, hexametaphosphate, or a pharmaceutically acceptable salt thereof. According to another embodiment, the bisphosphonate is alendronic acid, etidronic acid, zoledronic acid, or medronic acid, and the P:Ca molar ratio is as defined above.

[0121] According to some embodiments, the calcium content (Ca content) of such compositions containing a stabilizer is about 1% to about 39%, about 5% to about 39%, about 10% to about 39%, about 15% to about 39%, about 20% to about 38%, about 25% to about 38%, or about 30% to about 38% by weight of the dry ACC particles. The terms "Ca content" and "calcium content" are used interchangeably herein and refer to the calcium content of the ACC in the final composition.

[0122] In certain embodiments, the P:Ca molar ratio is about 1:40 to about 1:1, and the Ca content is about 20% to about 39% by weight. In some embodiments, the molar ratio is 1:28 to about 1:3, and the Ca content is about 30% to about 38% by weight of the dry ACC particles. In other embodiments, the molar ratio is 1:25 to about 1:5, and the Ca content is about 30% to about 36% by weight of the dry ACC particles.

[0123] According to some embodiments, the stabilizer is an inorganic polyphosphate or bisphosphonate as defined above, and the molar ratio between the P atoms of the stabilizer and the Mg atoms of the amorphous magnesium carbonate (AMC) (P:Mg molar ratio) is about 1:90 to 1:1. In one embodiment, the P:Mg molar ratio is about 1:40 to about 1:1. In a further embodiment, the P:Mg molar ratio is about 1:35 to about 1:2. In certain embodiments, the P:Mg molar ratio is about 1:30 to about 1:3. In certain embodiments, the P:Mg molar ratio is about 1:28 to about 1:3. In other embodiments, the P:Mg molar ratio is about 1:25 to about 1:4. In a further embodiment, the P:Mg molar ratio is about 1:20 to about 1:5. In another embodiment, the P:Mg molar ratio is about 1:20 to about 1:6. In certain embodiments, the molar ratio of P:Mg is about 1:15 to about 1:5. In another specific embodiment, the molar ratio of P:Mg is about 1:25 to about 1:5. According to some embodiments, the inorganic polyphosphate is pyrophosphate, triphosphate, hexametaphosphate, or a pharmaceutically acceptable salt thereof. According to another embodiment, the bisphosphonate is alendronic acid, etidronic acid, zoledronic acid, or medronic acid, and the molar ratio of P:Mg is as defined above.

[0124] According to some embodiments, the magnesium content (Mg content) of such compositions containing a stabilizer is about 1% to about 39%, about 5% to about 39%, about 10% to about 39%, about 15% to about 39%, about 20% to about 38%, about 25% to about 38%, or about 30% to about 38% by weight of the dry ACC particles. The terms "Mg content" and "magnesium content" are used interchangeably herein and refer to the magnesium content of the AMC in the final composition.

[0125] In certain embodiments, the P:Mg molar ratio is about 1:40 to about 1:1, and the Ca content is about 20% to about 39% by weight. In some embodiments, the molar ratio is 1:28 to about 1:3, and the Mg content is about 30% to about 38% by weight of the dry ACC particles. In other embodiments, the molar ratio is 1:25 to about 1:5, and the Mg content is about 30% to about 36% by weight of the dry AMC particles.

[0126] According to some embodiments, the stabilized ACC or AMC powder contains about 1% to about 18%, about 4% to about 15%, and about 6% to about 10% absorbed and adsorbed water by weight. According to some embodiments, the stabilizer is a polyphosphate or bisphosphonate, and the molar ratio between the phosphorus atoms of the stabilizer and the calcium atoms of the ACC is about 1:90 to 1:1. According to some embodiments, the stabilizer is a polyphosphate or bisphosphonate, and the molar ratio between the phosphorus atoms of the stabilizer and the magnesium atoms of the AMC is about 1:90 to 1:1.

[0127] In some embodiments, the stabilizer is selected from the group consisting of polyphosphate, phosphorylated amino acid, bisphosphonate, citric acid, tartaric acid, and any combination thereof. In one embodiment, the polyphosphate is selected from the group consisting of triphosphate, pyrophosphate, and hexametaphosphate, the phosphorylated amino acid is phosphoserine or phosphothreonine, and the bisphosphonate is selected from the group consisting of alendronate, etidronic acid, zoledronic acid, and medronic acid. In some embodiments, the polyphosphate is an inorganic polyphosphate.

[0128] According to one embodiment, the stabilizer is selected from the group consisting of organic acids, phosphorylated, phosphonated, sulfated or sulfonated organic compounds, phosphate or sulfate esters of hydroxycarboxylic acids, phosphorylated amino acids, bisphosphonates, organic polysulfonates, hydroxyl-containing organic compounds, derivatives thereof, proteins and any combination thereof.

[0129] According to another embodiment, the stabilizer is selected from the group consisting of phosphoserine, adenosine triphosphate, adenosine diphosphate, phytic acid, citric acid, etidronic acid, pyrophosphate, polyphosphate, inorganic triphosphate, hexametaphosphate, ethanol, and any combination thereof.

[0130] According to some embodiments, the stabilizer is selected from the group consisting of polyphosphates, organic acids, phosphorylated amino acids, phosphorylated, phosphonated, sulfated or sulfonated organic compounds, phosphorus or sulfate esters of hydroxycarboxylic acids, bisphosphonates, organic polyphosphates, polyphosphates, hydroxyl-containing organic compounds, derivatives thereof, proteins and any combination thereof.

[0131] According to some embodiments, the stabilizer is selected from the group consisting of triphosphate or a salt thereof, phosphoserine, citric acid, sodium triphosphate and citric acid, adenosine triphosphate, adenosine diphosphate, phytic acid, etidronic acid, pyrophosphate, polyphosphate, hexametaphosphate, a salt thereof, ethanol, and any combination thereof.

[0132] According to some embodiments, the stabilizer in steps (ii) and (iv) is sodium tripolyphosphate.

[0133] According to some embodiments, the stabilizer is added at any one of the following stages: (a) before bubbling or pressurizing the CO gas, (b) after bubbling or pressurizing the CO gas, (c) before adding the alkaline earth metal salt, (d) simultaneously with adding the alkaline earth metal salt, or (e) after adding the alkaline earth metal salt and adding sodium tripolyphosphate.

[0134] According to some embodiments, the total amount / concentration of the stabilizer is 2 to 15% by weight of the amount / concentration of the alkaline earth metal halide. Considering that the stabilizer may be added in two or more steps, the amount / concentration of the stabilizer refers to the total amount / concentration added. In embodiments referring to the concentration of the alkaline earth metal salt, it is clear that the corresponding concentration units are used for the stabilizer. According to some embodiments, the amount / concentration of the stabilizer is 3 to 13% by weight of the amount / concentration of the alkaline earth metal halide. According to some embodiments, the amount / concentration of the stabilizer is 4 to 15% by weight of the amount / concentration of the alkaline earth metal halide. According to some embodiments, the amount / concentration of the stabilizer is 5 to 12% by weight of the amount / concentration of the alkaline earth metal halide. According to some embodiments, the amount / concentration of the stabilizer is 8 to 15% by weight of the total amount / concentration of the alkaline earth metal halide. According to some embodiments, the total concentration of sodium tripolyphosphate added in all steps together is 2 to 15% by weight of the added CaCl2. According to some embodiments, the total concentration of sodium tripolyphosphate added in all steps collectively is 2-15% by weight of the added MgCl. According to some embodiments, the total concentration of sodium tripolyphosphate added in all steps collectively is 2-15% by weight of the added MgSO. According to some embodiments, in the continuous process of the present invention, the stabilizer is added constantly to maintain a concentration of alkaline earth metal salt of 2-15% by weight.

[0135] According to some embodiments, the methods of the present invention are carried out / performed at atmospheric pressure.

[0136] According to some embodiments, the method of the present invention is carried out / performed under a CO2 pressure of 1 to 60 bar.

[0137] According to any one of the above embodiments, the method is carried out at ambient temperature. According to some embodiments, the method is carried out at a temperature ranging from about 15°C to about 60°C.

[0138] According to any one of the above embodiments, the term "recovering the obtained stabilized amorphous alkaline earth metal carbonate" encompasses any recovery method, such as continuously recovering the precipitant. According to any one of the above embodiments, recovering the obtained stabilized amorphous alkaline earth metal carbonate may be performed by filtering the stabilized amorphous alkaline earth metal carbonate precipitant, or by any other method common in continuously recovering solid precipitants, for example. According to some embodiments, the method includes filtering the obtained alkaline earth metal carbonate, such as ACC or AMC. According to some embodiments, the method further includes washing the obtained ACC or AMC.

[0139] According to some embodiments, recovering further comprises drying the recovered precipitant, which may be done by any method, such as air, fan, vacuum, oven, microwave oven, and combinations thereof, or any other known method.

[0140] According to some embodiments, the present invention provides a method for preparing a stabilized amorphous alkaline earth metal carbonate or a method for fixing CO2, the method comprising: (i) dissolving NaOH or NH4OH in an aqueous solution to adjust the pH to 10 or higher; (ii) dissolving sodium tripolyphosphate in the solution obtained in step (i) and starting to bubble or pressurize the solution of step (i) with CO2 gas; (iii) adding an alkaline earth metal salt to the solution of step (ii), thereby precipitating an amorphous alkaline earth metal carbonate; (iv) adding sodium tripolyphosphate to the solution of step (iii); (v) recovering the resulting amorphous stabilized alkaline earth metal carbonate; CO2 is constantly introduced into the solution during steps (ii) and (iii), and NaOH or NH4OH is added in an amount equal to at least 2 molar equivalents of the alkaline earth metal carbonate added. According to one embodiment, the alkaline earth metal carbonate is CaCl2. According to one embodiment, the alkaline earth metal carbonate is MgSO4. According to some embodiments, CaCl2 is added to a concentration of 0.2 to 0.6 M. According to some embodiments, MgSO4 is added to a concentration of 0.3 to 0.9 M. According to some embodiments, the reaction is carried out at ambient pressure. According to other embodiments, the reaction is carried out at a pressure of 1 to 60 bar or 5 to 56 bar. According to some embodiments, the pH is maintained above 10 during the process. According to some embodiments, the method further comprises filtering the resulting stabilized ACC or AMC. According to some embodiments, the filtration is carried out within 2 minutes of adding CaCl2 or MgSO4. According to some embodiments, the method further comprises washing the stabilized ACC or AMC.

[0141] According to some embodiments, the present invention provides a method for preparing an alkaline earth metal carbonate or a method for fixing CO2, the method comprising: (i) dissolving NaOH or NH4OH in an aqueous solution to adjust the pH to 10 or higher; (ii) dissolving sodium tripolyphosphate in the solution of step (i) and beginning to bubbling or pressurize CO2 into the solution; (iii) adding an alkaline earth metal salt and a tripolyphosphate to the solution of step (ii), thereby precipitating an amorphous alkaline earth metal carbonate; CO2 is constantly introduced into the solution during steps (ii) and (iii), and NaOH or NH4OH is added in an amount equal to or greater than 2 molar equivalents of the stabilized alkaline earth metal salt added. According to one embodiment, the alkaline earth metal carbonate is CaCl2. According to one embodiment, the alkaline earth metal carbonate is MgSO4. According to some embodiments, CaCl2 is added to a concentration of 0.2 to 0.6 M. According to some embodiments, MgSO4 is added to a concentration of 0.3 to 0.9 M. According to some embodiments, the reaction is carried out at ambient pressure. According to other embodiments, the reaction is carried out at a pressure of 1 to 60 bar or 5 to 56 bar. According to some embodiments, the pH is maintained above 10 during the process. According to some embodiments, the method further comprises filtering the stabilized ACC. According to some embodiments, the filtration is carried out within 2 minutes of adding CaCl2 or MgSO4. According to some embodiments, the method further comprises washing the stabilized ACC or AMC.

[0142] According to some embodiments, the method of the present invention comprises: (i) dissolving a base and sodium tripolyphosphate as a stabilizer in an aqueous solution, the pH of the resulting aqueous solution being 8 or higher; (ii) bubbling or pressurizing CO gas into the solution obtained in step (i), followed by adding CaCl and, optionally, adding sodium tripolyphosphate as a stabilizer to the solution; (iii) optionally adding sodium tripolyphosphate as a stabilizer to the solution obtained in step (ii); (iv) recovering the resulting stabilized amorphous calcium carbonate, The base is selected from NaOH and NH4OH and is added in an amount equal to at least 2 equivalents of CaCl2, optionally with CaCl2 selected from anhydrous, monohydrate, and dihydrate. According to some embodiments, the method includes adding a stabilizer in step (ii). According to some embodiments, the method includes adding a stabilizer in step (iii). According to some embodiments, the method includes adding a stabilizer in steps (ii) and (iii). According to some embodiments, the pH is maintained at a value of 8 or higher, 9 or higher, 10 or higher, 11 or higher, or 12 or higher throughout the preparation process. According to some embodiments, the pH is maintained at a value of 8 to 12 throughout the preparation process. According to some embodiments, the reaction is carried out at ambient pressure. According to other embodiments, the reaction is carried out at a pressure of 1 to 60 bar or 5 to 56 bar. According to some embodiments, the pH is maintained above 10 throughout the process. According to some embodiments, the method further includes filtering the stabilized ACC. According to some embodiments, the filtration is performed within 2 minutes of adding CaCl. According to some embodiments, the method further comprises washing the stabilized ACC. According to some embodiments, the method further comprises drying the stabilized ACC.

[0143] According to some embodiments, the method of the present invention comprises: (i) dissolving a base and sodium tripolyphosphate as a stabilizer in an aqueous solution, the pH of the resulting aqueous solution being 8 or higher; (ii) adding CaCl and optionally sodium tripolyphosphate as stabilizers to the solution obtained in step (i), followed by bubbling or pressurizing with CO gas; (iii) optionally adding sodium tripolyphosphate as a stabilizer to the solution obtained in step (ii); (iv) recovering the resulting amorphous calcium carbonate, The base is selected from NaOH and NH4OH and is added in an amount equal to at least 2 equivalents of CaCl2, optionally with CaCl2 selected from anhydrous, monohydrate, and dihydrate. According to some embodiments, the method includes adding a stabilizer in step (ii). According to some embodiments, the method includes adding a stabilizer in step (iii). According to some embodiments, the method includes adding a stabilizer in steps (ii) and (iii). According to some embodiments, the pH is maintained at a value of 8 or higher, 9 or higher, 10 or higher, 11 or higher, or 12 or higher throughout the preparation process. According to some embodiments, the pH is maintained at a value of 8 to 12 throughout the preparation process. According to some embodiments, the reaction is carried out at ambient pressure. According to other embodiments, the reaction is carried out at a pressure of 1 to 60 bar or 5 to 56 bar. According to some embodiments, the pH is maintained above 10 throughout the process. According to some embodiments, the method further includes filtering the stabilized ACC. According to some embodiments, the filtration is performed within 2 minutes of the start of the addition of CO bubbling. According to some embodiments, the method further comprises washing the stabilized ACC. According to some embodiments, the method further comprises drying the stabilized ACC.

[0144] According to some embodiments, the method of the present invention comprises: (i) dissolving a base and sodium tripolyphosphate as a stabilizer in an aqueous solution, the pH of the resulting aqueous solution being 8 or higher; (ii) bubbling or pressurizing CO gas into the solution obtained in step (i), followed by adding MgSO and, optionally, adding sodium tripolyphosphate as a stabilizer to the solution; (iii) optionally adding sodium tripolyphosphate as a stabilizer to the solution obtained in step (ii); (iv) recovering the resulting amorphous magnesium carbonate; The base is selected from NaOH and NH4OH and is added in an amount equal to at least 2 equivalents of MgSO4, optionally with MgSO4 heptahydrate. According to some embodiments, the method comprises adding a stabilizer in step (ii). According to some embodiments, the method comprises adding a stabilizer in step (iii). According to some embodiments, the method comprises adding a stabilizer in steps (ii) and (iii). According to some embodiments, the pH is maintained at a value of 8 or greater, 9 or greater, 10 or greater, 11 or greater, or 12 or greater throughout the preparation process. According to some embodiments, the pH is maintained at a value between 8 and 12 throughout the preparation process. According to some embodiments, the reaction is carried out at ambient pressure. According to other embodiments, the reaction is carried out at a pressure between 1 and 60 bar or between 5 and 56 bar. According to some embodiments, the pH is maintained above 10 throughout the process. According to some embodiments, the method further comprises filtering the stabilized AMC. According to some embodiments, the filtration is performed within 2 minutes of adding the MgSO. According to some embodiments, the method further comprises washing the stabilized AMC. According to some embodiments, the method further comprises drying the stabilized AMC.

[0145] According to some embodiments, the method of the present invention comprises: (i) dissolving a base and sodium tripolyphosphate as a stabilizer in an aqueous solution, the pH of the resulting aqueous solution being 8 or higher; (ii) adding MgSO4 and optionally sodium tripolyphosphate as stabilizers to the solution obtained in step (i), followed by bubbling or pressurizing with CO2 gas, and optionally adding sodium tripolyphosphate as a stabilizer to the solution; (iii) optionally adding sodium tripolyphosphate as a stabilizer to the solution obtained in step (ii); (iv) recovering the resulting amorphous magnesium carbonate; The base is selected from NaOH and NH4OH and is added in an amount equal to at least 2 equivalents of MgSO4, optionally with MgSO4 heptahydrate. According to some embodiments, the method comprises adding a stabilizer in step (ii). According to some embodiments, the method comprises adding a stabilizer in step (iii). According to some embodiments, the method comprises adding a stabilizer in steps (ii) and (iii). According to some embodiments, the pH is maintained at a value of 8 or greater, 9 or greater, 10 or greater, 11 or greater, or 12 or greater throughout the preparation process. According to some embodiments, the pH is maintained at a value between 8 and 12 throughout the preparation process. According to some embodiments, the reaction is carried out at ambient pressure. According to other embodiments, the reaction is carried out at a pressure between 1 and 60 bar or between 5 and 56 bar. According to some embodiments, the pH is maintained above 10 throughout the process. According to some embodiments, the method further comprises filtering the stabilized AMC. According to some embodiments, the filtration occurs within 2 minutes of the start of CO bubbling. According to some embodiments, the method further comprises washing the stabilized AMC. According to some embodiments, the method further comprises drying the stabilized AMC.

[0146] According to some embodiments, the method for preparing stabilized calcium carbonate comprises: providing an aqueous solution having a pH of 8 or greater; (i) continuously adding a base, sodium triphosphate, and calcium chloride to the aqueous solution; (ii) continuously bubbling or pressurizing CO gas through the solution; and (iii) continuously recovering the resulting amorphous calcium carbonate, wherein the base is selected from NaOH and NHOH and is added in an amount of at least 2 molar equivalents of calcium chloride, and the pH is maintained constant at 8 or greater throughout the entire process. According to some embodiments, the pH of the starting solution is 9 or greater, 10 or greater, 11 or greater, or 12 or greater. According to some embodiments, the pH is maintained at a value of 8 or greater, 9 or greater, 10 or greater, 11 or greater, or 12 or greater throughout the entire process. According to some embodiments, the pH is maintained at a value between 8 and 12 throughout the entire preparation process. According to some embodiments, the reaction is carried out at ambient pressure. According to other embodiments, the reaction is carried out at a pressure between 1 and 60 bar or between 5 and 56 bar. According to some embodiments, the pH is maintained above 10 during the process. According to some embodiments, the method further comprises filtering the stabilized ACC. According to some embodiments, the method further comprises drying the stabilized ACC. According to some embodiments, the method further comprises washing the stabilized ACC.

[0147] According to some embodiments, the method for preparing stabilized calcium carbonate comprises: providing an aqueous solution having a pH of 8 or greater; (i) continuously adding a base, sodium triphosphate, and magnesium sulfate to the aqueous solution; (ii) continuously bubbling or pressurizing CO gas through the solution; and (iii) recovering the resulting amorphous calcium carbonate, wherein the base is selected from NaOH and NHOH and is added in an amount of at least 2 molar equivalents of calcium chloride; and the pH is maintained constant at 8 or greater throughout the entire process. According to some embodiments, the pH of the starting solution is 9 or greater, 10 or greater, 11 or greater, or 12 or greater. According to some embodiments, the pH is maintained at a value of 8 or greater, 9 or greater, 10 or greater, 11 or greater, or 12 or greater throughout the entire process. According to some embodiments, the pH is maintained at a value between 8 and 12 throughout the entire preparation process. According to some embodiments, the reaction is carried out at ambient pressure. According to other embodiments, the reaction is carried out at a pressure between 1 and 60 bar or between 5 and 56 bar. According to some embodiments, the pH is maintained above 10 during the process. According to some embodiments, the method further comprises filtering the stabilized AMC. According to some embodiments, the method further comprises drying the stabilized AMC. According to some embodiments, the method further comprises washing the stabilized AMC.

[0148] According to another aspect, the present invention provides stabilized amorphous calcium carbonate prepared by a method according to any one of the above embodiments and aspects. All terms, embodiments, and definitions disclosed in any one of the above aspects apply and are encompassed herein as well.

[0149] According to some embodiments, the present invention provides a method for producing a pharmaceutical composition comprising: (i) dissolving a base in an aqueous solution, the resulting solution having a pH of 8 or greater; (ii) bubbling or pressurizing CO2 gas into the solution obtained in step (i) followed by adding a salt of an alkaline earth metal; or adding an alkaline earth metal salt to the solution obtained in step (i), followed by bubbling or pressurizing CO gas through the solution; thereby precipitating an amorphous alkaline earth metal carbonate; (iii) recovering the obtained amorphous alkaline earth metal carbonate precipitate; The method includes adding at least one stabilizer in at least one of the following steps: (a) before bubbling or pressurizing the CO2 gas, (b) after bubbling or pressurizing the CO2 gas, (c) before adding the alkaline earth metal salt, (d) simultaneously with adding the alkaline earth metal salt, or (e) after adding the alkaline earth metal salt.

[0150] According to some embodiments, the present invention provides a method for producing a pharmaceutical composition comprising: (i) dissolving a base and a stabilizer in an aqueous solution, the resulting solution having a pH of 8 or greater; (ii) bubbling or pressurizing CO2 gas through the solution obtained in step (i), followed by adding an alkaline earth metal salt and, optionally, adding a stabilizer to the solution, or adding an alkaline earth metal salt to the solution obtained in step (i), followed by bubbling or pressurizing CO2 gas through the solution and, optionally, adding a stabilizer; (iii) thereby precipitating a stabilized alkaline earth metal carbonate; (iv) optionally adding a stabilizer to the solution obtained in step (ii); (v) recovering the obtained amorphous alkaline earth metal carbonate; CO2 is constantly introduced into the solution during step (ii) and, if present, during step (iii), and the stabilizers in step (i) and, if present, step (ii) and / or step (iii) are the same or different.

[0151] According to some embodiments, the present invention provides a method for producing a pharmaceutical composition comprising: (i) dissolving a base in an aqueous solution; (ii) dissolving a stabilizer in the solution obtained in step (i) and then bubbling or pressurizing CO2 gas into the solution, in which dissolution of the stabilizer and initiation of CO2 introduction by bubbling or pressurization are performed in either order; (iii) adding an alkaline earth metal salt and optionally a stabilizer to the solution obtained in step (ii), thereby precipitating an amorphous alkaline earth metal carbonate; (iv) optionally adding a stabilizer to the solution obtained in step (iii), CO2 is constantly introduced into the solution during step (ii) and, if CO2 is added, during step (iii), and the stabilizers in steps (ii) and (iii) and step (iv) are the same or different.

[0152] According to some embodiments, the present invention provides a method for producing a pharmaceutical composition comprising: (i) dissolving NaOH or NH4OH in an aqueous solution to adjust the pH to 10 or higher; (ii) dissolving sodium tripolyphosphate in the solution obtained in step (i) and starting to bubble or pressurize the solution with CO2 gas; (iii) adding an alkaline earth metal halide or sulfate to the solution of step (ii); (iv) adding sodium tripolyphosphate to the solution of step (iii) or simultaneously with step (iii), CO2 is constantly introduced into the solution during steps (ii) and (iii), and NaOH or NH4OH is added in an amount equal to at least 2 molar equivalents of the alkaline earth metal added.

[0153] According to some embodiments, the present invention provides a method for producing a pharmaceutical composition comprising: (i) dissolving a base in an aqueous solution; (ii) dissolving a stabilizer in the solution obtained in step (i) and then bubbling or pressurizing CO2 gas into the solution, in which dissolution of the stabilizer and initiation of CO2 introduction by bubbling or pressurization are performed in either order; (iii) adding a calcium salt, such as calcium chloride, and optionally a stabilizer to the solution obtained in step (ii), thereby precipitating ACC; (iv) optionally adding a stabiliser to the solution obtained in step (iii), CO2 is constantly introduced into the solution during step (ii) and, if CO2 is added, during step (iii), and the stabilizers in steps (ii) and (iii) and step (iv) are the same or different.

[0154] According to some embodiments, the present invention provides a method for producing a pharmaceutical composition comprising: (i) dissolving NaOH or NH4OH in an aqueous solution to adjust the pH to 10 or higher; (ii) dissolving sodium tripolyphosphate in the resulting solution of step (i) and beginning to bubbling or pressurize the solution with CO2 gas; (iii) adding CaCl to the solution of step (ii); (iv) adding sodium tripolyphosphate to the solution of step (iii) or simultaneously with step (iii), CO2 is constantly introduced into the solution during steps (ii) and (iii), and NaOH or NH4OH is added in an amount equal to at least 2 molar equivalents of the CaCl2 added.

[0155] According to some embodiments, the present invention provides a method for producing a pharmaceutical composition comprising: (i) dissolving a base in an aqueous solution; (ii) dissolving a stabilizer in the solution obtained in step (i) and then bubbling or pressurizing CO2 gas into the solution, in which dissolution of the stabilizer and initiation of CO2 introduction by bubbling or pressurization are performed in either order; (iii) adding a magnesium salt, such as magnesium sulfate, and optionally a stabilizer to the solution obtained in step (ii), thereby precipitating ACC; and (iv) optionally adding a stabiliser to the solution obtained in step (iii), CO2 is constantly introduced into the solution during step (ii) and, if CO2 is added, during step (iii), and the stabilizers in steps (ii) and (iii) and step (iv) are the same or different.

[0156] According to some embodiments, the present invention provides a method for producing a pharmaceutical composition comprising: (i) dissolving NaOH or NH4OH in an aqueous solution to adjust the pH to 10 or higher; (ii) dissolving sodium tripolyphosphate in the resulting solution of step (i) and beginning to bubbling or pressurize the solution with CO2 gas; (iii) adding MgCl or magnesium sulfate to the solution of step (ii); (iv) adding sodium tripolyphosphate to the solution of step (iii) or simultaneously with step (iii), CO2 is constantly introduced into the solution during steps (ii) and (iii), and NaOH or NH4OH is added in an amount equal to at least 2 molar equivalents of the magnesium salt added.

[0157] According to some embodiments, the present invention provides a method for producing a pharmaceutical composition comprising: (i) dissolving NaOH or NH4OH and sodium tripolyphosphate as a stabilizer in an aqueous solution, wherein the pH of the resulting aqueous solution is 8 or higher; (ii) bubbling or pressurizing CO gas into the solution obtained in step (i), followed by adding CaCl and / or NH OH, and optionally adding sodium tripolyphosphate as a stabilizer to the solution; (iii) optionally adding sodium tripolyphosphate as a stabilizer to the solution obtained in step (ii); (iv) recovering the obtained amorphous carbonates of Ca and / or Mg.

[0158] According to some embodiments, the present invention provides a method for producing a pharmaceutical composition comprising: (i) dissolving NaOH or NH4OH and sodium tripolyphosphate as a stabilizer in an aqueous solution, wherein the pH of the resulting aqueous solution is 8 or higher; (ii) adding CaCl or MgSO as a stabilizer and optionally sodium tripolyphosphate to the solution obtained in step (i), followed by bubbling or pressurizing with CO gas; (iii) optionally adding sodium tripolyphosphate as a stabilizer to the solution obtained in step (ii); (iv) recovering the obtained amorphous carbonates of Ca and / or Mg.

[0159] According to some embodiments, the present invention provides stabilized alkaline earth metal carbonates obtained or obtainable by a process comprising providing an aqueous solution having a pH of 8 or greater, and (i) continuously adding a base, at least one stabilizer, and an alkaline earth metal or salt thereof to the aqueous solution, (ii) continuously bubbling or pressurizing CO gas through the solution, and (iii) continuously recovering the resulting stabilized amorphous alkaline earth metal carbonate, wherein the pH is maintained at 8 or greater during the entire process. According to some embodiments, the alkaline earth metal or salt thereof is selected from CaCl and MgSO.

[0160] According to yet another aspect, the present invention provides the use of stabilized amorphous alkaline earth metal carbonates, such as ACC, AMC and combinations thereof, in agriculture and veterinary medicine.

[0161] Having now generally described the invention, the same will be more readily understood by reference to the following examples, which are provided by way of illustration and are not intended to limit the invention. [Example]

[0162] The characteristics of the products prepared in the examples described herein are shown in Table 1 below. Some examples were repeated with slight variations in conditions. A detailed description of these variations is provided in Table 1.

[0163] Example 1. Preparation of ACC with 10% stabilizer and 2 equivalents of NaOH introduced in one addition step with CO2 bubbling at atmospheric pressure. Sodium hydroxide pellets (7 g, 2 molar equivalents of CaCl) were dissolved in 250 mL of deionized water. A stabilizer (sodium tripolyphosphate, STPP, also known as sodium triphosphate) was then added to the solution (1.26 g, CaCl . CO gas was bubbled through the solution for at least 2 minutes before adding the calcium reagent and then bubbled continuously throughout the reaction after adding the calcium source. . 2H2O was added in small portions to the above solution mixture with a steady, gentle stream of CO2 until dissolved (due to the exothermic reaction). The reaction mixture was homogenized with a homogenizer, and CO2 was further bubbled into the reaction mixture for a total time of 10 minutes, yielding 3.2 g of a white solid after filtration, washing with water, and drying. In this particular example, the solid was dried in an oven at 100°C for 15 minutes with an air purge. The calculated yield was approximately 30% based on the estimated ACC composition and the molar amount of calcium source.

[0164] Example 2. Preparation of ACC with 5% stabilizer and 2 equivalents of NaOH introduced in one step with CO2 bubbling at atmospheric pressure. Sodium hydroxide pellets (7 g, 2 molar equivalents of CaCl) were dissolved in 200 mL of deionized water. A stabilizer (sodium tripolyphosphate, STPP) was then added to the solution (0.63 g, CaCl . 12.61 g of CaCl2 was dissolved in 50 mL of deionized water (5% by weight of the amount of 2H2O). CO2 gas was bubbled through the solution to degas the solution from other gases before adding the calcium source, and was bubbled continuously throughout the reaction after adding the calcium source. . 2H2O was added to the above solution mixture with a constant gentle CO2 flow. The reaction mixture was homogenized with a homogenizer, and CO2 was further bubbled into the reaction mixture for a total time of 10 minutes to yield 7.8 g of a white solid (73% yield based on the estimated ACC composition and the molar amount of calcium source). The calcium content was 39.7 wt%. The surface area of ​​the resulting ACC was 18.49 m 2 / g.

[0165] Example 3. Preparation of ACC with CO2 bubbling at atmospheric pressure, 10% stabilizer added in two portions, and 2 equivalents of NaOH. A quantity of NaOH pellets (7 g, 2 equivalents) was dissolved in 250 mL of deionized water. A stabilizer (sodium tripolyphosphate, STPP) (0.63 g, 5% by weight of the amount of CaCl.2H0) was then dissolved. CO gas was then bubbled through the solution for various times before adding the calcium source and continuously during the reaction with the calcium source. A quantity of 12.61 g of CaCl was added. . 2H2O was added in small portions with a steady gentle flow of CO2 to the above solution mixture until dissolved (the reaction is exothermic). The reaction mixture was homogenized with a homogenizer, and additional CO2 was bubbled into the reaction mixture. Another portion of 0.63 g of STPP was added, and the reaction was continued for another 5 minutes. The total yield was 5.5 g of a white solid (51% yield) with a calcium content of 34.4 wt%. The surface area of ​​the resulting ACC was 11 m2 / g.

[0166] The reaction may be carried out at higher pressures (5 bar to 200 bar). It may be carried out using additional ion sources of other metals (e.g., Mg, Fe, Mn, Cr, Co, etc.).

[0167] It appears possible to increase the yield of the reaction by increasing the amount of base.

[0168] Example 4. Preparation of ACC with CO bubbling at atmospheric pressure without adding sodium hydroxide and 10% stabilizer all at once. In an Erlenmeyer flask filled with 250 mL of deionized water, 1.26 g (CaCl2 . A stabilizer (sodium tripolyphosphate, STPP) in an amount of 10% by weight of the amount of 2H2O was dissolved. A quantity of 12.61 g of CaCl2 2H2O was added in small portions to the above solution mixture with a constant gentle CO2 flow until dissolved (the reaction is exothermic). The reaction mixture was homogenized with a homogenizer, and CO2 was further bubbled into the reaction mixture for a total of 10 minutes. The yield of recovered product was only 1.2 g, and TGA showed only 2% by weight of CO2 released, indicating a very low content of carbonated product. The product was found to be amorphous.

[0169] Example 5. Two-stage preparation of ACC without added sodium hydroxide and 10% stabilizer and with CO2 bubbling at atmospheric pressure. In an Erlenmeyer flask filled with 250 mL of deionized water, 0.63 g (CaCl2 .A stabilizer (sodium tripolyphosphate, STPP) in an amount of 5% by weight of the amount of 2H2O was dissolved. A 12.61 g amount of CaCl2 2H2O was added in small portions with a constant gentle CO2 flow into the above solution mixture until dissolved. Another 0.63 g portion of the stabilizer was added as a powder. The reaction mixture was homogenized with a homogenizer, and CO2 was further bubbled into the reaction mixture for a total of 10 minutes. The yield of the recovered product was only 1 g, and TGA showed only 2% by weight of CO2 released, indicating a very low calcium carbonate content. The material was amorphous.

[0170] Example 6. Preparation of ACC without added sodium hydroxide and with 10% stabilizer added in two steps by CO2 bubbling at atmospheric pressure In an Erlenmeyer flask filled with 250 mL of deionized water, 0.63 g (CaCl2 . A stabilizer (sodium tripolyphosphate, STPP) in an amount of 5% by weight of the amount of 2H2O was dissolved. A quantity of 12.61 g of CaCl2 2H2O was added in small portions with a constant gentle CO2 flow into the above solution mixture until dissolved. Another portion of 0.63 g of STPP was added, the reaction mixture was homogenized with a homogenizer, and CO2 was further bubbled into the reaction mixture for a total of 10 minutes. The yield of recovered product was only 1.2 g, and TGA showed only 2% by weight CO2 release, indicating a very low calcium carbonate content. The material was amorphous and contained 23.9% calcium. The surface area of ​​the resulting ACC was 32.9 m 2 / g.

[0171] Example 7. Preparation of ACC with CO2 bubbling at atmospheric pressure, 10% stabilizer added all at once, and 3 equivalents of sodium hydroxide Sodium hydroxide pellets (10.5 g, CaCl . 2H2O) was dissolved in 200 mL of deionized water, and then a stabilizer (sodium tripolyphosphate, STPP) was dissolved in the solution (1.26 g, CaCl2 .CO was then bubbled into the solution before adding the calcium source and continuously bubbled during the reaction with the calcium source. A quantity of 12.61 g of CaCl22H2O dissolved in 50 mL of water was added with a constant gentle CO2 flow. The reaction mixture was homogenized with a homogenizer, and CO2 was further bubbled into the reaction mixture for a total time of 10 minutes to give 9.5 g of a white solid (88% yield for ACC). The calcium content was 34.3 wt%. The surface area of ​​the resulting ACC was 44.45 m 2 / g.

[0172] Example 8. Preparation of ACC using CO bubbling at atmospheric pressure, calcium chloride, sodium tripolyphosphate (STPP) as a stabilizer (single addition), and 3 equivalents of sodium hydroxide Sodium hydroxide pellets (10.5 g, CaCl . 2H2O) was dissolved in 150 mL of deionized water, and then a stabilizer (sodium tripolyphosphate, STPP) was dissolved in the solution (1.26 g, CaCl2 . The reaction mixture was homogenized with a homogenizer, and CO was further bubbled into the reaction mixture for a total time of 10 minutes, yielding 7.6 g of a white solid (71% yield for ACC). The surface area of ​​the resulting ACC was 28.6 m. 2 / g.

[0173] Example 9. Preparation of ACC with CO2 bubbling at atmospheric pressure, 10% stabilizer added in two portions, and 3 equivalents of sodium hydroxide Sodium hydroxide pellets (10.5 g, CaCl . 2H2O) was dissolved in 200 mL of deionized water, and then a stabilizer (sodium tripolyphosphate, STPP) was dissolved in the solution (0.63 g, CaCl2. 2H2O). CO2 was then bubbled into this solution before adding the calcium source and continuously bubbled during the reaction with the calcium source. Another portion of 0.63 g of STPP dissolved in 50 mL of water and an amount of 12.61 g of CaCl2H2O was added with a constant gentle flow of CO2. The reaction mixture was homogenized with a homogenizer, and additional CO2 was bubbled into the reaction mixture, allowing the reaction to continue for an additional 5 minutes. The total yield was 9.5 g of a white solid (88% yield for ACC).

[0174] Example 10. Preparation of ACC with 10% stabilizer added in one step and 3 equivalents of sodium hydroxide in the presence of 10 bar CO in a 1 L pressure reactor Sodium hydroxide pellets (10.5 g, CaCl . 2H2O) was dissolved in 200 mL of deionized water, and then a stabilizer (sodium tripolyphosphate, STPP) was dissolved in the solution (1.26 g, CaCl2 . 2H2O。 12.61 g of CaCl2H2O dissolved in 50 mL of water was added all at once to the above mixture, and the resulting solution was mixed and then introduced into a pressure reactor. CO2 gas was then flushed through the solution in the reactor to degas the solution. The reactor was sealed and pressurized with 10 bar of CO2 for 10 minutes. The reaction mixture was stirred by a mechanical rotor stirring shaft set at 1000 rpm. After filtration, washing with water, and drying in an oven at 100 °C with an air purge for 15 minutes, the reaction yield was 6.9 g of a white solid (64% yield for ACC).

[0175] Example 11. Preparation of ACC with 10% stabilizer and 3 equivalents of sodium hydroxide added in two steps in the presence of 10 bar CO in a 1 L pressure reactor Sodium hydroxide pellets (10.5 g, CaCl . 2H2O) was dissolved in 200 mL of deionized water, and then a stabilizer (sodium tripolyphosphate, STPP) was dissolved in the solution (0.63 g, CaCl2 .A quantity of 12.61 g of CaCl2 2H2O dissolved in 40 mL of water, a stabilizer (sodium tripolyphosphate, STPP) was then separately dissolved in 10 mL of water (0.63 g, CaCl2 . The 5% by weight of 2H2O, calcium solution, and STPP solution were premixed to a total volume of 50 mL and added all at once to the above 200 mL mixture. The resulting solution was mixed and added to the reactor, and CO2 was flushed through the solution in the reactor. The reactor was then sealed, and the pressure was set to 10 bar for 10 minutes. The reaction mixture was stirred with a mechanical rotor stirring shaft set at 1000 rpm. After filtration, washing, and drying in a 100 °C oven for 15 minutes with an air purge, the product yield was 7.1 g of a white solid (66% yield for ACC).

[0176] Example 12. Preparation of ACC with 10% stabilizer and 2 equivalents of sodium hydroxide added in one step in the presence of 10 bar CO in a 1 L pressure reactor Sodium hydroxide pellets (7g, CaCl2 . 2H2O) was dissolved in 200 mL of deionized water, and then a stabilizer (sodium tripolyphosphate, STPP) was dissolved in the solution (1.26 g, CaCl2 . 2H2O。 A quantity of 12.61 g of CaCl2H2O dissolved in 50 mL of water was added to the above mixture all at once, and the resulting solution was mixed and added to the reactor. CO2 was flushed through the solution in the reactor. The reactor was then sealed, and the CO2 pressure was set to 10 bar for a total time of 10 minutes. The reaction mixture was mixed with a mechanical rotor stirring shaft set at 1000 rpm to give 6.7 g of a white solid (62% yield for ACC).

[0177] Example 13. Preparation of ACC with 10% stabilizer and 2 equivalents of sodium hydroxide added in two steps in the presence of 10 bar CO in a 1 L pressure reactor Sodium hydroxide pellets (7g, CaCl2 .2H2O) was dissolved in 200 mL of deionized water, and then a stabilizer (sodium tripolyphosphate, STPP) was dissolved in the solution (0.63 g, CaCl2 . A quantity of 12.61 g of CaCl2 2H2O dissolved in 40 mL of water, a stabilizer (sodium tripolyphosphate, STPP) was then separately dissolved in 10 mL of water (0.63 g, CaCl2 . The calcium solution and STPP solution were premixed to a total volume of 50 mL and added all at once to the above 200 mL mixture. The resulting solution was mixed and added to the reactor, and CO was flushed through the solution in the reactor. The reactor was then sealed, and the CO pressure was set to 10 bar for a total time of 10 minutes. The reaction mixture was stirred with a mechanical rotor stirring shaft set at 1000 rpm to yield 6.7 g of a white solid (62% yield for ACC).

[0178] Example 14. Preparation of ACC with 10% stabilizer and 2 equivalents of sodium hydroxide added in two steps in the presence of 20 bar CO in a 1 L pressure reactor Sodium hydroxide pellets (7g, CaCl2 . 2H2O) was dissolved in 250 mL of deionized water, and then a stabilizer (sodium tripolyphosphate, STPP) was dissolved in the solution (0.63 g, CaCl2 . 5% by weight of the amount of 2H2O, CO2 was pressurized into a sealed reactor at 20 bar for 10 minutes at room temperature. The reactor was opened, the solution was transferred to a conical flask, and the mixture was mixed with a homogenizer. A quantity of 12.61 g of powdered CaCl2 2H2O was added to the above mixture, followed by 0.63 g of powdered stabilizer (sodium tripolyphosphate, CaCl2 . 2H2O) was added. The resulting solution was homogenized for an additional 3 minutes to give 7.7 g of a white solid (72% yield for ACC).

[0179] Example 15. Preparation of ACC in a 1 L pressure reactor with 10% stabilizer and 3 equivalents of sodium hydroxide added in two steps in the presence of 20 bar CO2. Sodium hydroxide pellets (10.5 g, CaCl . 2H2O) was dissolved in 250 mL of deionized water, and then a stabilizer (sodium tripolyphosphate, STPP) was dissolved in the solution (0.63 g, CaCl2 . 5% by weight of the amount of 2H2O, CO2 was pressurized into a sealed reactor at 20 bar for 10 minutes at room temperature. The reactor was opened, the solution was transferred to a conical flask, and the mixture was mixed with a homogenizer. A quantity of 12.61 g of powdered CaCl2 2H2O was added to the above mixture, followed by 0.63 g of powdered stabilizer (sodium tripolyphosphate, CaCl2 . 2H2O) was added. The resulting solution was homogenized for an additional 3 minutes to give 10.4 g of a white solid (97% yield for ACC).

[0180] Example 16. Preparation of ACC with 10% stabilizer added in two additions and 2 equivalents of sodium hydroxide in the presence of 20 bar CO in a 1 L pressure reactor Sodium hydroxide pellets (7g, CaCl2 . 2H2O) was dissolved in 200 mL of deionized water, and then a stabilizer (sodium tripolyphosphate, STPP) was dissolved in the solution (0.63 g, CaCl2 . CO2, 5% by weight of the amount of 2H2O, was pressurized into a sealed reactor at 20 bar for 10 minutes at room temperature. The reactor was opened, the solution was transferred to a conical flask, and the mixture was mixed with a homogenizer. A quantity of 12.61 g of powdered CaCl2 2H2O dissolved in 40 mL of deionized water was added to the above mixture, followed by 0.63 g of powdered stabilizer (sodium tripolyphosphate, CaCl2) dissolved in 10 mL of deionized water. . 2H2O) was added. The resulting solution was homogenized for an additional 3 minutes to give 7.6 g of a white solid (71% yield for ACC).

[0181] Example 17. Preparation of ACC with 10% stabilizer and 3 equivalents of sodium hydroxide added in two steps in the presence of 20 bar CO in a 1 L pressure reactor Sodium hydroxide pellets (10.5 g, CaCl . 2H2O) was dissolved in 200 mL of deionized water, and then a stabilizer (sodium tripolyphosphate, STPP) was dissolved in the solution (0.63 g, CaCl2 . A solution containing 5% by weight of the amount of CaCl2 2H2O, and CO2 was pressurized into a sealed reactor at room temperature at 20 bar for 10 minutes. The reactor was opened, the solution was transferred to a conical flask, and the mixture was mixed with a homogenizer. A quantity of 12.61 g of powdered CaCl2 2H2O dissolved in 40 mL of deionized water was added to the above mixture, followed by 0.63 g of powdered stabilizer (sodium tripolyphosphate, CaCl2) dissolved in 10 mL of deionized water. . 2H2O) was added. The resulting solution was homogenized for an additional 3 minutes to give 9.8 g of a white solid (91% yield for ACC).

[0182] Example 18. Preparation of ACC without 10% stabilizer and sodium hydroxide added in one step in the presence of 10 bar CO in a 1 L pressure reactor In 200 mL of deionized water, a stabilizer (sodium tripolyphosphate, STPP) was dissolved in the solution (1.26 g, CaCl . 2H2O。 A quantity of 12.61 g of CaCl2H2O dissolved in 50 mL of water was added to the above mixture all at once, and the resulting solution was mixed and added to the reactor. CO2 was flushed through the solution in the reactor. The reactor was then sealed and the pressure was set to 10 bar for a total time of 10 minutes. The reaction mixture was stirred with a mechanical rotor stirring shaft set at 1000 rpm to give 1.1 g of a white solid (10% yield for ACC).

[0183] Example 19. Preparation of ACC without 10% stabilizer and sodium hydroxide added in one step in the presence of 20 bar CO in a 1 L pressure reactor In 200 mL of deionized water, a stabilizer (sodium tripolyphosphate, STPP) was dissolved in the solution (1.26 g, CaCl . 2H2O。 12.61 g of CaCl2H2O dissolved in 50 mL of water was added to the above mixture in one portion, and the resulting solution was mixed and added to the reactor. CO2 gas was flushed through the solution in the reactor. The reactor was then sealed and the pressure was set to 20 bar for a total time of 10 minutes. The reaction mixture was stirred with a mechanical rotor stirring shaft set at 1000 rpm to give 1.1 g of a white solid (10% yield for ACC).

[0184] Example 20. Same preparation as Example 7 and Example 12, except no stabilizer was added. When ACC was prepared without the addition of stabilizers as detailed in Examples 7 and 12, the resulting ACC crystallized immediately in solution.

[0185] Example 21. Preparation of ACC (2730) with 10% stabilizer and 2 equivalents of NHOH solution added in one step in the presence of 10 bar CO in a 1 L pressure reactor. Ammonium hydroxide solution (25 wt.% NH3) (11.7 mL, CaCl2 . 2H2O) was dissolved in 200 mL of deionized water, and then a stabilizer (sodium tripolyphosphate, STPP) was added to the solution (1.26 g, CaCl2 . 12.61 g of CaCl2 dissolved in 50 mL of deionized water was added. CO2 was bubbled through the solution before adding the calcium source. .2H2O was added to the above solution mixture with a steady, gentle stream of CO2 gas. The reactor was sealed, and the reaction continued for 1 minute at 10 bar and 25°C while stirring with a mechanical rotor shaft set at 1000 rpm. After 1 minute, the reaction was stopped, and then the reactor was opened and the product was filtered through a Buchner funnel using filter paper. The product was dried in a vented oven at 100°C to yield 8.8 g of a white solid (82% yield for ACC). The amorphous content of ACC was 100% as determined by XRD. The loss on drying of ACC was 10.4%, and the calcium content was 32.9 wt%.

[0186] Example 22. Preparation of AMC with 6.4% stabilizer added in one addition and 2 equivalents of ammonium hydroxide in the presence of 15 bar CO in a 1 L pressure reactor. (2754) In 200 mL of deionized water, a stabilizer (sodium tripolyphosphate, STPP) was dissolved (0.898 g, 6.4 wt. % of the amount of MgSO4) simultaneously with a 25 wt. % ammonia solution (2 equivalents relative to MgSO4, 15.8 mL). 28.57 g of MgSO4 dissolved in 50 mL of water. . 7H2O was added to the mixture in one portion, and the resulting solution was mixed for 30 seconds and added to the reactor. CO2 gas was flushed through the solution in the reactor. The reactor was then sealed, and the pressure was set to 15 bar for a total time of 3 minutes. The reaction mixture was stirred with a mechanical rotor shaft set at 1000 rpm, and after precipitation with 30 mL of ethanol, 1 g of a white solid was obtained. The product was washed with 500 mL of deionized water to remove unreacted starting materials and salts and dried in an oven without a vent to a constant LOD of 4.7% and XRD of 100% AMC (6% yield for AMC).

[0187] Example 23. Preparation of AMC with 6.4% stabilizer added in one addition and 2 equivalents of ammonium hydroxide in the presence of 15 bar CO in a 1 L pressure reactor (2755) In 200 mL of deionized water, a stabilizer (sodium tripolyphosphate, STPP) was dissolved (0.898 g, 6.4 wt. % of the amount of MgSO4) simultaneously with a 25 wt. % ammonia solution (2 equivalents relative to MgSO4, 15.8 mL). 28.57 g of MgSO4 dissolved in 50 mL of water. . 7H2O was added to the mixture all at once, and the resulting solution was mixed for 30 seconds and added to the reactor. CO2 gas was flushed through the solution in the reactor. The reactor was then sealed, and the pressure was set to 15 bar for a total time of 5 minutes. The reaction mixture was stirred by a mechanical rotor shaft set at 1000 rpm, and after precipitation with 50 mL of ethanol, 1.5 g of a white solid was obtained. The product was washed with 500 mL of deionized water to remove unreacted starting materials and salts and dried in an oven without a vent to a constant LOD of 5.1%, XRD 100% AMC (9.4% yield for AMC).

[0188] Example 24. Preparation of AMC (2761) with 2 equivalents of aqueous ammonia in the presence of 15 bar of CO in a 1 L pressure reactor without added stabilizer To 200 mL of deionized water was added 25 wt% ammonia solution (2 equivalents, 15.8 mL). 28.57 g of MgSO4 dissolved in 50 mL of water. . 7H2O was added to the above solution all at once, and the resulting mixture was mixed for 30 seconds and added to the reactor. CO2 was flushed through the solution in the reactor. The reactor was then sealed, and the pressure was set to 15 bar for a total time of 3 minutes. The reaction mixture was stirred with a mechanical rotor stirring shaft set at 1000 rpm, and after precipitation with 50 mL of ethanol, 1.1 g of a white solid was obtained. The product was washed with 500 mL of deionized water to remove unreacted starting materials and salts and dried in an oven without a vent to a constant LOD of 3.6%, with XRD showing predominantly AMC with minor nesquehonite (6% yield for AMC).

[0189] Example 25. Preparation of AMC with 6.4% stabilizer and 2 equivalents of ammonium added in one addition in the presence of 15 bar CO in a 1 L pressure reactor (2766) To 200 mL of deionized water, 25 wt% (2 equivalents, 15.8 mL) ammonia solution was added simultaneously with the stabilizer (sodium tripolyphosphate, STPP, 0.898 g, 6.4 wt% of the amount of MgSO4). 28.57 g of MgSO4 dissolved in 50 mL of water was added. . 7H2O was added to the above solution all at once, and the resulting mixture was mixed for 30 seconds and added to the reactor. CO2 was flushed through the solution in the reactor. The reactor was then sealed, and the pressure was set to 15 bar for a total time of 3 minutes. The reaction mixture was stirred with a mechanical rotor stirring shaft set at 1000 rpm, and after precipitation with 50 mL of ethanol, 6.3 g of a white solid was obtained. The product was isolated as is without washing with deionized water and dried in an oven without a vent to a constant LOD of 5.4% and XRD 100% AMC (55% yield for AMC).

[0190] Example 26. Preparation of ACC with 10% stabilizer and 2 equivalents of NHOH solution added in one step in the presence of 10 bar CO in a 1 L pressure reactor Ammonium hydroxide solution (25 wt.% NH3) (11.7 mL, CaCl2 . 2H2O) was dissolved in 200 mL of deionized water, and then a stabilizer (pyrophosphate, hexametaphosphate, phytic acid, or citric acid) was added to the solution (CaCl2 . Dissolve 12.61 g of CaCl in 50 mL of deionized water. CO was bubbled through the solution before adding the calcium source. .2H2O is added to the above solution mixture with a steady, gentle stream of CO2 gas. The reactor is sealed and the reaction is continued for 1 minute at 10 bar and 25°C while stirring with a mechanical rotor shaft set at 1000 rpm. After 1 minute, the reaction is stopped, then the reactor is opened and the product is filtered through a Buchner funnel using filter paper. The product is dried in a vented oven at 100°C to yield 8-10 g of a white solid. The amorphous content of ACC is 100% as determined by XRD.

[0191] Example 27. Preparation of AMC with 6.4% stabilizer and 2 equivalents of ammonium added in one addition in the presence of 15 bar CO in a 1 L pressure reactor To 200 mL of deionized water, 25 wt. % ammonia solution (2 equivalents, 15.8 mL) is added simultaneously with a stabilizer (pyrophosphate, hexametaphosphate, phytic acid, or citric acid, 6.4 wt. % of the amount of MgSO4). 28.57 g of MgSO4 dissolved in 50 mL of water. . 7H2O is added to the above solution all at once, and the resulting mixture is mixed for 30 seconds and added to the reactor. CO2 is flushed through the solution in the reactor. The reactor is then sealed and the pressure is set to 15 bar for a total time of 3 minutes. The reaction mixture is stirred with a mechanical rotor stirring shaft set at 1000 rpm, and after precipitation with 50 mL of ethanol, 6.3 g of a white solid is obtained. The product is isolated directly without washing with deionized water and dried in an oven without a vent to a constant LOD of approximately 5.5%, XRD 100% AMC (approximately 55% yield for AMC).

[0192] Example 28. Preparation of ACC with 10% stabilizer and 2 equivalents of NH4OH solution added in one step in the presence of 10 bar CO2 in a 1 L pressure reactor Ammonium hydroxide solution (25 wt.% NH3) (11.7 mL, CaCl2 .2H2O) was dissolved in 200 mL of deionized water, a stabilizer (tripolyphosphate in combination with one of the following: pyrophosphate, hexametaphosphate, phytic acid, or citric acid), and then the solution (CaCl2 . Dissolve 12.61 g of CaCl in 50 mL of deionized water. CO was bubbled through the solution before adding the calcium source. . 2H2O is added to the above solution mixture with a steady, gentle stream of CO2 gas. The reactor is sealed and the reaction is continued for 1 minute at 10 bar and 25°C while stirring with a mechanical rotor shaft set at 1000 rpm. After 1 minute, the reaction is stopped, then the reactor is opened and the product is filtered through a Buchner funnel using filter paper. The product is dried in a vented oven at 100°C to yield 8-10 g of a white solid. The amorphous content of ACC is 100% as determined by XRD.

[0193] Example 29. Preparation of AMC with 6.4% stabilizer and 2 equivalents of ammonium added in one addition in the presence of 15 bar CO in a 1 L pressure reactor To 200 mL of deionized water, add 25 wt. % ammonia solution (2 equivalents, 15.8 mL) simultaneously with a stabilizer (tripolyphosphate combined with one of the following: pyrophosphate, hexametaphosphate, phytic acid, or citric acid, 6.4 wt. % of the amount of MgSO4). Dissolve 28.57 g of MgSO4 in 50 mL of water. . 7H2O is added to the above solution all at once, and the resulting mixture is mixed for 30 seconds and added to the reactor. CO2 is flushed through the solution in the reactor. The reactor is then sealed and the pressure is set to 15 bar for a total time of 3 minutes. The reaction mixture is stirred with a mechanical rotor stirring shaft set at 1000 rpm, and after precipitation with 50 mL of ethanol, 6.3 g of a white solid is obtained. The product is isolated directly without washing with deionized water and dried in an oven without a vent to a constant LOD of approximately 5.5%, XRD 100% AMC (approximately 55% yield for AMC).

[0194] The analytical results of the above examples are summarized in Table 1, highlighting some key issues. First, the presence of a base is important to convert CO2 into carbonate and bicarbonate ions. Indeed, the stoichiometry of the reaction with alkaline earth metal salts requires at least two equivalents of base (OH) to complete the chemical reaction. - The inventors have shown that higher levels of base equivalents can be beneficial to reassure high yields of amorphous product.

[0195] Without being bound by any particular theory, it is believed that the base can react directly with CO2 before the alkaline earth metal salt is introduced. However, it can also first react with the metal salt to form an M-OH species (M = Ca or Mg), which is itself a base, and then react with CO2. This means that if the industrial waste material is an alkaline earth metal hydroxide, CO2 can form the desired amorphous carbonate without the addition of a base. However, to our knowledge, current industrial waste containing calcium and magnesium consists primarily of alkaline earth metal chlorides and sulfates, obtained from dissolving metal-containing rocks in either sulfuric or hydrochloric acid. Magnesium sulfate (Epsom salt) is highly soluble and therefore can be used in the given example, while calcium sulfate (gypsum) is a highly insoluble material.

[0196] The presence of a base is also important for stabilizing the as-formed amorphous carbonate in the reaction solution before isolating and drying it. Our experience shows that during large-scale industrial processing of these amorphous carbonates, process steps where the amorphous product is still in a suspended or wet state are highly vulnerable to crystallization via the solid-solution-solid crystallization mechanism. The presence of a stabilizer, as well as a basic pH level, is important for suppressing crystallization in these process steps, or when the amorphous product is intended to be used as a suspension for practical applications. In basic solutions, the solubility of amorphous carbonates is dramatically reduced. In contrast, they are significantly more soluble under acidic and even neutral conditions compared to their associated crystalline phases. Therefore, in the given examples, the pH of the reaction solution was maintained above pH 8.

[0197] The most commonly used bases are sodium hydroxide and dissolved ammonia (NH4OH). Furthermore, these bases are also inexpensive and are produced in very large quantities. The process, based on one or other criteria, is determined based on economic evaluation, availability, location, and environmental factors associated with the industrial plant for producing the product of the present invention.

[0198] The presence of a stabilizer is very important when forming ACC, as shown in Example 20. The amount of stabilizer and its order of introduction are not critical. Most examples used 10% stabilizer, but as can be seen from Example 2, 5% stabilizer is also suitable. The presence of a stabilizer in the formation of AMC is not critical to the ability to produce AMC that is stable under dry conditions, as shown in Example 24. However, a stabilizer is required for the long-term stability of AMC in humid environments, or when suspended in aqueous solution for certain applications, because AMC stability decreases dramatically and rapidly crystallizes in the absence of a stabilizer. The resulting ACC has very similar molecular configuration in all examples that give high yields, regardless of synthetic variations. However, the chemical content of AMC and its molecular arrangement can vary widely based on the variables and sequence changes during its synthesis.

[0199] Furthermore, recent detailed studies using modern solid-state NMR techniques have revealed that both amorphous and crystalline phases of magnesium carbonate also contain magnesium bicarbonate species and their salts (e.g., Leukel et al., Hydrogen Bonding in Amorphous Alkaline Earth Carbonates, Inorg. Chem. 2018, 57:11289-11298; Moore et al., Quantitative Identification of Metastable Magnesium Carbonate Minerals by Solid-State NMR). 13 (C NMR Spectroscopy. Environ. Sci. Technol. 2015, 49, 657-664; and Tanaka et al., Transformation process of amorphous magnesium carbonate in aqueous solution. Journal of Mineralogical and Petrological Sciences, Volume 114, pages 105-109, 2019). This is not very surprising given the disordered structure of AMC, but their presence in the crystalline phase is somewhat surprising.

[0200] Many other stabilizers can be used in addition to those exemplified. Tripolyphosphate is a very reliable stabilizer, very low cost, and is used in very large quantities in food processing (preservation). Nevertheless, any one of the following stabilizers can be used: polyphosphates, organic acids, phosphorylated amino acids, phosphorylated, phosphonated, sulfated, or sulfonated organic compounds, phosphoric or sulfate esters of hydroxycarboxylic acids, bisphosphonates, organic polyphosphates, polyphosphates, hydroxyl-containing organic compounds, their derivatives, proteins, and any combination thereof. More specific examples of useful stabilizers include phosphoserine, citric acid, sodium triphosphate and citric acid, adenosine triphosphate, adenosine diphosphate, phytic acid, etidronic acid, pyrophosphate, polyphosphate, hexametaphosphate, ethanol, salts thereof, and any combination thereof.

[0201] Additionally, waste calcium and magnesium salts may be found in or produced in the vicinity of locations where they may be found during the production of phosphate salts from naturally occurring calcium phosphate minerals.

[0202] Although no examples of mixed amorphous calcium-magnesium carbonates are given, their formation as stable amorphous compositions is highly feasible, as recently demonstrated in WO 2022162667, "Particles Comprising Amorphous Divalent Metal Carbonate."

[0203] While the present invention has been described hereinabove in its preferred embodiments, modifications can be made thereto without departing from the spirit and nature of the invention as defined in the appended claims.

[0204] [Table 1-1]

[0205] [Table 1-2]

[0206] [Table 1-3]

[0207] [Table 1-4]

[0208] footnote: 4 PACKS solution: Half the amount of stabilizer, i.e., 5% by weight, was added to CaCl2 . The stabilizer is dissolved in a 2H2O solution to obtain solution (I). Meanwhile, the remaining half of the stabilizer, i.e., 5% by weight, is dissolved in a basic solution containing NaOH or NH4OH to obtain solution (II). The resulting reaction solution contains a mixture of solutions (I) and (II).

[0209] 2 PACKS solution: The total amount of stabilizer, i.e., 10% by weight, is dissolved solely in a basic solution, i.e., NaOH or NH4OH.

Claims

1. 1. A method for preparing a stabilized amorphous alkaline earth metal carbonate, the method comprising: (i) dissolving a base in an aqueous solution, the resulting solution having a pH of 8 or greater; (ii) adding CO to the solution obtained in step (i); ２ bubbling or pressurizing the gas followed by adding a salt of an alkaline earth metal; or Adding an alkaline earth metal salt to the solution obtained in step (i), followed by CO ２ bubbling or pressurizing a gas through the solution, thereby precipitating an amorphous alkaline earth metal carbonate; (iii) recovering the resulting amorphous alkaline earth metal carbonate precipitate, said method comprising the steps of: (a) removing CO ２ (b) before bubbling or pressurizing the gas; ２ adding at least one stabilizer after bubbling or pressurizing the gas, at least one of: (c) before adding the alkaline earth metal salt; (d) simultaneously with adding the alkaline earth metal salt; or (e) after adding the alkaline earth metal salt.

2. The method comprises: (i) dissolving a base in an aqueous solution, the resulting solution having a pH of 8 or greater; (ii) adding CO to the solution obtained in step (i); ２ bubbling or pressurizing the gas, followed by adding a salt of an alkaline earth metal; (iii) recovering the resulting stabilized amorphous alkaline earth metal carbonate precipitate.

3. (a) adding a stabilizer to the solution obtained in step (i) by adding CO ２ 3. The method of claim 2, comprising adding the salt of an alkaline earth metal at a stage selected from (a) before bubbling or pressurizing the gas, (b) after adding the salt of the alkaline earth metal, or (c) both (a) and (b).

4. The method comprises: (i) dissolving a base in an aqueous solution, the resulting solution having a pH of 8 or greater; (ii) adding the salt of the alkaline earth metal to the solution obtained in step (i), followed by CO ２ bubbling or pressurizing a gas through the solution; (iii) recovering the resulting stabilized amorphous alkaline earth metal carbonate precipitate.

5. (a) adding the stabilizer simultaneously with the addition of the alkaline earth metal salt; (b) adding CO ２ 5. The method of claim 4, comprising adding the gas at a stage selected from (c) both (a) and (b) before bubbling or pressurizing.

6. (i) dissolving a base and a stabilizer in an aqueous solution; (ii) adding CO to the solution obtained in step (i); ２ bubbling or pressurizing a gas, followed by adding a salt of an alkaline earth metal and, optionally, adding a stabilizer to the solution; (iii) optionally adding a stabilizer to the solution obtained in step (ii); and (iv) recovering the resulting stabilized alkaline earth metal carbonate.

7. (i) dissolving a base and a stabilizer in an aqueous solution; (ii) adding a salt of an alkaline earth metal to the solution obtained in step (i) and, optionally, adding a stabilizer to the solution obtained in step (i), followed by CO ２ bubbling or pressurizing a gas; (iii) optionally adding a stabilizer to the solution obtained in step (ii); and (iv) recovering the resulting stabilized alkaline earth metal carbonate.

8. The method according to any one of claims 6 to 7, comprising adding a stabilizer in step (ii).

9. The method according to any one of claims 6 to 8, comprising adding a stabilizer in step (iii).

10. 10. The method of any one of claims 1 to 9, wherein the pH of the solution obtained in step (i) is 8 or higher, 9 or higher, 10 or higher, 11 or higher, or 12 or higher.

11. 11. The method of any one of claims 1 to 10, wherein the precipitation of the alkaline earth metal carbonate is achieved within 2 minutes.

12. 1. A method for preparing a stabilized amorphous alkaline earth metal carbonate, the method comprising: providing an aqueous solution having a pH of 8 or greater; (i) sequentially adding a base, at least one stabilizer, and an alkaline earth metal to the aqueous solution; and (ii) adding CO to the solution. ２ (iii) continuously bubbling or pressurizing the gas; and (iii) continuously recovering the resulting amorphous alkaline earth metal carbonate precipitate, wherein the pH is maintained constant at or above 8 during the entire process.

13. The method according to any one of claims 1 to 12, wherein the base is selected from alkali metal hydroxides, ammonia or ammonium hydroxide.

14. 14. The method of claim 13, wherein the alkali metal hydroxide is sodium hydroxide.

15. 14. The method of claim 13, wherein the base is ammonium hydroxide.

16. 16. The method according to any one of claims 1 to 15, wherein the salt of the alkaline earth metal is selected from water-soluble halides, nitrates and sulfates of the alkaline earth metals, and hydrates thereof.

17. 17. The method of claim 16, wherein the alkaline earth metal salt is selected from calcium chloride, calcium bromide, calcium nitrate, magnesium chloride, magnesium sulfate, magnesium nitrate, and combinations thereof.

18. 18. The method of claim 17, wherein the combination of alkaline earth metal salts comprises a combination of a calcium salt and a magnesium salt, and the salts are water-soluble salts.

19. 18. The method of claim 17, wherein the alkaline earth metal salt is calcium chloride.

20. 20. The method of claim 19, wherein the method comprises adding 0.03M to 0.8M calcium chloride.

21. 18. The method of claim 17, wherein the alkaline earth metal salt is magnesium chloride.

22. 22. The method of claim 21, wherein the method comprises adding 0.04M to 1M magnesium chloride.

23. 23. The method of any one of claims 1 to 22, wherein the stabilizer is selected from the group consisting of polyphosphates, inorganic polyphosphates, organic acids, phosphorylated amino acids, phosphorylated organic compounds, phosphonated organic compounds, sulfated or sulfonated organic compounds, phosphate or sulfate esters of hydroxycarboxylic acids, bisphosphonates, organic polyphosphates, polyphosphates, hydroxyl-containing organic compounds, derivatives thereof, proteins, and any combination thereof.

24. 24. The method of claim 23, wherein the stabilizer is selected from the group consisting of tripolyphosphate or a salt thereof, phosphoserine, citric acid, sodium triphosphate and citric acid, adenosine triphosphate, adenosine diphosphate, phytic acid, etidronic acid, pyrophosphate, polyphosphate, hexametaphosphate, ethanol, a salt thereof, and any combination thereof.

25. 25. The method of claim 24, wherein the stabilizer is sodium tripolyphosphate.

26. 26. The method of any one of claims 1 to 25, wherein the pH is maintained at a value of at least 8, at least 9, at least 10, at least 11, or at least 12 during the entire process of preparation.

27. 27. The method of any one of claims 1 to 26, wherein the concentration of the added base is at least 2 molar equivalents of the concentration of the alkaline earth metal salt.

28. 28. The method according to any one of claims 1 to 27, wherein the total amount of stabilizer added is 2 to 15% by weight of the amount of the alkaline earth metal salt.

29. 29. The method of any one of claims 1 to 28, wherein the reaction is carried out at atmospheric pressure.

30. 29. The process of any one of claims 1 to 28, wherein the reaction is carried out under a pressure of 1 to 60 bar.

31. The method of any one of claims 1 to 30, wherein the reaction is carried out at ambient temperature.

32. 32. The method of any one of claims 1 to 31, wherein recovering the stabilized amorphous alkaline earth metal carbonate comprises filtering and drying the resulting stabilized amorphous alkaline earth metal carbonate precipitate.

33. (i) dissolving a base and sodium tripolyphosphate as a stabilizer in an aqueous solution, wherein the pH of the resulting aqueous solution is 8 or higher; (ii) adding CO to the solution obtained in step (i); ２ is bubbled or pressurized, followed by CaCl ２ and optionally adding sodium tripolyphosphate as a stabilizer to said solution; (iii) optionally adding sodium tripolyphosphate as a stabilizer to the solution obtained in step (ii); (iv) recovering the stabilized amorphous calcium carbonate obtained, The base is NaOH and NH ４ OH and at least two equivalents of CaCl ２ and optionally, CaCl ２ is anhydrous, monohydrate, and dihydrate CaCl ２ The method of claim 1 , wherein the compound is selected from the group consisting of:

34. (i) dissolving a base and sodium tripolyphosphate as a stabilizer in an aqueous solution, wherein the pH of the resulting aqueous solution is 8 or higher; (ii) CaCl ２ followed by the addition of CO ２ bubbling or pressurizing a gas; (iii) optionally adding sodium tripolyphosphate as a stabilizer to the solution obtained in step (ii); (iv) recovering the stabilized amorphous calcium carbonate obtained, The base is NaOH and NH ４ OH and at least two equivalents of CaCl ２ and optionally, CaCl ２ is anhydrous, monohydrate, or dihydrate CaCl ２ The method of claim 1 , wherein the compound is selected from the group consisting of:

35. (i) dissolving a base and sodium tripolyphosphate as a stabilizer in an aqueous solution, wherein the pH of the resulting aqueous solution is 8 or higher; (ii) adding CO to the solution obtained in step (i); ２ Bubbling or pressurizing the gas followed by MgSO ４ to the solution; (iii) optionally adding sodium tripolyphosphate as a stabilizer to the solution obtained in step (ii); (iv) recovering the resulting stabilized amorphous magnesium carbonate; The base is NaOH and NH ４ OH and at least 2 equivalents of MgSO ４ and optionally MgSO ４ is anhydrous or heptahydrate MgSO ４ The method of claim 1, wherein

36. (i) dissolving a base and sodium tripolyphosphate as a stabilizer in an aqueous solution, wherein the pH of the resulting aqueous solution is 8 or higher; (ii) adding MgSO as a stabilizer to the solution obtained in step (i); ４ and optionally adding sodium tripolyphosphate, followed by CO ２ bubbling or pressurizing a gas through the solution; (iii) optionally adding sodium tripolyphosphate as a stabilizer to the solution obtained in step (ii); (iv) recovering the resulting stabilized amorphous magnesium carbonate; The base is NaOH and NH ４ OH and at least 2 equivalents of MgSO ４ and optionally MgSO ４ is anhydrous or heptahydrate MgSO ４ The method of claim 1, wherein

37. 37. The method of any one of claims 33 to 36, comprising adding said stabilizer in step (iii).

38. The base is NaOH and NH ４ OH, and 2 or 3 molar equivalents of CaCl or MgSO ４ The method of any one of claims 33 to 37, wherein the hydroxybenzoate is added in an amount equal to

39. A method for preparing stabilized amorphous calcium carbonate, comprising: providing an aqueous solution having a pH of 8 or greater; (i) sequentially adding a base, sodium triphosphate, and calcium chloride to the aqueous solution; and (ii) adding CO to the solution. ２ (iii) continuously bubbling or pressurizing the gas; and (iii) continuously recovering the resulting amorphous calcium carbonate, wherein the base is NaOH and NH ４ 13. The method of claim 12, wherein the calcium chloride is selected from the group consisting of HCl, ...

40. A method for preparing stabilized amorphous magnesium carbonate, comprising: providing an aqueous solution having a pH of 8 or greater; (i) sequentially adding a base, sodium triphosphate, and magnesium sulfate to the aqueous solution; and (ii) adding CO to the solution. ２ (iii) continuously bubbling or pressurizing the gas; and (iii) continuously recovering the resulting amorphous magnesium carbonate, wherein the base is NaOH and NH ４ 13. The method of claim 12, wherein the magnesium sulfate is selected from the group consisting of magnesium sulphate, ...

41. 41. The method of any one of claims 33 to 40, wherein the pH is maintained at a value of at least 8, at least 9, at least 10, at least 11, or at least 12 during the entire process of preparation.

42. 41. The method according to any one of claims 33 to 40, wherein the pH is maintained at a value between 8 and 13 during the entire process of preparation.

43. A stabilized amorphous alkaline earth metal carbonate prepared by the method of any one of claims 1 to 42.

44. 44. Use of the stabilized amorphous alkaline earth metal carbonate of claim 43 in agriculture and veterinary medicine.

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