Method for producing hydrogen and magnetite from rocks

Abstract

A system and method for sequential carbonation and serpentinization / hydration reactions involving processed ores rich in olivine and / or pyroxene, typically found in mafic and ultramafic igneous rocks, to sequester carbon, evolve hydrogen gas, and produce iron oxide as magnetite and magnesium carbonate as magnesite. Precious or rare metals, such as nickel, cobalt, chromium, and rare earth elements, are concentrated in the remaining ore, potentially facilitating their recovery from any gangue material.

Description

Technical Field

[0001] One or more embodiments of the present disclosure generally relate to systems and methods for producing hydrogen, producing magnetite, and / or obtaining additional desired products from ores containing cancrinite or pyroxene (such as kimberlite or ultramafic rock) by a preselected chemical process. In one or more embodiments, the systems and methods promote a carbonation reaction and / or a serpentinization / hydration reaction involving ores rich in cancrinite and pyroxene to sequester carbon dioxide, liberate hydrogen, produce magnetite and magnesite, and / or obtain other desired products, the other desired products including rare metals that are often essential for various green technologies (e.g., batteries, energy storage, solar power generation), and which would otherwise be mined using carbon-intensive methods.

Background Art

[0002] The environmental impact of greenhouse gases, mainly carbon dioxide (CO2) and methane (CH4), has been the subject of much public debate over the past few decades. More recently, voluntary private-sector efforts and government-mandated regulations to reduce greenhouse gas emissions into the environment have begun to be implemented. In addition to capturing and / or sequestering carbon dioxide and other greenhouse gases to reduce their release into the atmosphere, much research and development effort has been focused on the use of alternative means to replace fossil fuel combustion for energy generation in order to reduce the amount of carbon dioxide produced and / or the amount of carbon dioxide that needs to be captured and sequestered.

[0003] Hydrogen (H2) gas is promising as an energy source (e.g., as a hydrogen fuel or through the use of green ammonia) and as a chemical raw material (e.g., methanol, ammonia, hydrocarbon fuels) that produces little to no greenhouse gases when burned. In fact, when hydrogen gas is burned, only water is produced as a reaction product. However, hydrogen gas has traditionally been produced using fossil fuels (e.g., by natural gas / methane conversion in steam reformers), which produces carbon dioxide, a greenhouse gas, as a reaction product. For example, in the steam-methane reforming reaction described above, methane reacts with water vapor (i.e., water) to produce hydrogen gas and carbon monoxide. In the subsequent water-gas shift reaction, carbon monoxide further reacts with water vapor to produce carbon dioxide and additional hydrogen gas. The hydrogen gas is then separated from carbon dioxide by pressure swing adsorption, membrane separation, or other gas separation processes. Therefore, for example, most of the hydrogen produced in the operation of a smelter generates greenhouse gases, and in order to obtain meaningful benefits, these greenhouse gases need to be captured and sequestered.

[0004] Alternatively, hydrogen gas can be produced from hydrogen gas and oxygen by the electrolysis of water. The hydrogen gas is then separated from the oxygen by pressure swing adsorption, membrane separation, or other gas separation processes. The production of hydrogen by electrolysis or partial pyrolysis requires a considerable amount of electricity. Although at least some of the electricity required for hydrogen production by electrolysis and / or partial pyrolysis can be obtained from renewable sources (e.g., wind, solar, hydroelectric power), in practice, the majority of the electricity used for this purpose has traditionally and continues to be produced by the combustion of fossil fuels, which also produces greenhouse gases.

[0005] In certain geological formations, for example, in young oceanic crust near mid-ocean ridges as shown in Figures 1A to 1D, abiotic production of hydrogen gas is known to occur. These spontaneous reactions occur across a wide range of environmental conditions, including varying pH, oxygen fugacity, chemical composition, and pressure. While such reactions result in diverse and complex mineralogical compositions and chemical properties, no particular combination of reaction products is always produced as expected. In fact, as generally shown in the cross-sectional photographs of Figure 2, rock deposits capable of producing abiotic hydrogen often contain complex mixtures or layers of mineral phases that are difficult to extract, or they may not produce the desired products if other competing reactions take precedence based on in-situ geochemical conditions (e.g., various redox potentials (Eh), pH, pore water composition, gas chemical composition, and temperature). For example, hydrogen production is inherently variable, and its generation depends heavily on pH, Eh, and other aspects of fluid geochemistry in the pore space and on the mineral surface. Therefore, the complex kinetics of the reaction phases and the occurrence of competitive reactions under natural conditions (e.g., near-neutral pH, various oxygen fugaciities, and various pore water chemical properties) influence the products generated by these naturally occurring reactions. Certain geological formations and / or their rocks are also known to contain minerals that, under specific conditions, facilitate reactions with carbon dioxide to form carbonate mineral phases, such as carbonates. [Overview of the project] [Problems that the invention aims to solve]

[0006] Figure 3 provides a map highlighting examples of the locations of selected suitable and / or robust mafic and ultramafic deposits worldwide. Olivine-bearing and pyroxene-bearing ores may be found in such mafic and / or ultramafic formations. As can be seen from Figure 3, sources of mafic and ultramafic igneous rocks can be found in many locations, are very abundant, and occupy at least 10% of the Earth's continental crust, which demonstrates the global applicability of the solutions described herein. More recently, there has been growing interest in the potential of such sources of mafic and ultramafic igneous rocks to be used for carbon sequestration (mineralization) in carbonate mineral facies. However, despite the vast amount of prior research on carbon sequestration, there is considerable debate regarding the best mechanical reactions and optimized rates for carbon mineralization. Thus, the economic viability of these processes has not been fully developed, nor have the hydrogen-generating and carbon-sequestering capabilities of mafic and ultramafic rocks been realized. Furthermore, the economic uses of the particulate carbonated mineral phase produced from carbonization reactions are not recognized. Rather, proposals have been made to use such carbonated mineral phases as fill material or to dump them into oceans or lakes.

[0007] Despite the theoretical potential of utilizing such geological formations and / or their ores for geological hydrogen or other products, as well as potential carbon sequestration, the processes and kinetics of these reactions have not been rigorously evaluated or optimized. Furthermore, no process has been developed to produce hydrogen from these formations without generating alternative, and potentially harmful, mineral phases (e.g., antigorite, asbestos, or other serpentinite). Accordingly, the applicant recognized the need for a system and method to utilize specific geological formations and / or their ores to liberate hydrogen, produce magnetite and magnesite, and / or obtain other desired products such as rare metals / critical metals from formations containing olivine and pyroxene-rich ores, in addition to sequestrating carbon dioxide in magnesite or other mineral phases. [Means for solving the problem]

[0008] This disclosure provides one or more embodiments of a system and method for sequestrating carbon, generating hydrogen gas, and producing magnetite in addition to magnesite from ore containing olivine and pyroxene. In addition, precious or rare metals such as nickel, cobalt, chromium, and rare earth elements may be concentrated in the remaining ore, thereby facilitating the recovery of such precious or rare metals.

[0009] In exemplary embodiments, a method is provided for sequestrating carbon to produce hydrogen and magnetite. The method includes the step of obtaining an ore containing olivine or pyroxene. The ore can be crushed into smaller fragments by means of crushing or grinding, etc. The crushed ore can be introduced into a reactor capable of operating at a temperature above ambient temperature and a pressure above atmospheric pressure. The method may also include the step of introducing carbon dioxide (or a mixture of carbon dioxide and other gases such as nitrogen (N2), dihydrogen sulfide (H2S), sulfur dioxide (SO2)) into the reactor at a first temperature above ambient temperature for a first residence time to react at least a portion of the carbon dioxide with the ore. The method then includes the step of introducing water into the reactor at a second temperature for a second residence time to react at least a portion of the water with one or more remaining ores to produce at least magnetite and hydrogen gas. The reaction products, including hydrogen gas, magnesium carbonate (magnesite), magnetite, and other reaction products, along with the remaining ore, can be removed from the reactor.

[0010] In another embodiment, a method is provided for sequestrating carbon and producing hydrogen and magnetite from rock. The method includes the step of obtaining an ore containing olivine or pyroxene. As above, the ore may be broken down into smaller fragments by crushing or grinding, etc. The ore is introduced into a first reactor capable of operating at a pressure above atmospheric pressure at a first temperature above ambient temperature. The method also includes the step of introducing carbon dioxide (or a mixture of carbon dioxide and other gases such as nitrogen (N2), dihydrogen sulfide (H2S), sulfur dioxide (SO2)) into the first reactor at a first temperature for a first residence time, and reacting at least a portion of the carbon dioxide with the ore to produce at least magnesium carbonate. The remaining ore may be sent to a second reactor. The reaction products from the first reactor may be separated from the remaining ore and sent to the second reactor. The method includes the step of introducing water into a second reactor at a second temperature and for a second residence time to react at least a portion of the water with the remaining ore in the second reactor to produce at least magnetite and hydrogen gas. The reaction products, including hydrogen gas, magnesium carbonate (magnesite), magnetite, and other reaction products, and the remaining ore can be removed from the second reactor.

[0011] In yet another embodiment, a system is provided for sequestrating carbon and producing hydrogen and magnetite from rock. The system includes a source of ore containing olivine or pyroxene. The system may include a crusher or grinder, which is used to physically reduce the particle size of the ore introduced into the crusher or grinder from the source. The system may include a sieve used to receive the ore from the crusher and configured to allow ore particles to pass through to a pre-selected size. The system also includes a reactor having an inlet for receiving ore particles to a pre-selected size from the sieve and at least one outlet. The reactor has at least one additional inlet through which one or more of carbon dioxide or water can be introduced into the reactor (and in some embodiments the reactor may comprise two reactors: a first reactor having an additional inlet through which carbon dioxide can be introduced into the first reactor, and a second reactor having another additional inlet through which water can be introduced into the second reactor). The reactor is operable to react at least a portion of the incoming carbon dioxide with the ore in the first reactor at a first temperature and over a first residence time to produce at least magnesium carbonate. The reactor is also operable to react at least a portion of the water that enters the reactor through at least one additional inlet with the ore inside the reactor at a second temperature and over a second residence time to produce magnetite and hydrogen gas. In one or more embodiments the system also includes a gas separator connected to at least one outlet of the reactor and in fluid communication with it. The gas separator is configured to separate hydrogen gas from the gases exiting the reactor through at least one outlet of the reactor.

[0012] The corresponding means for carrying out these various steps are described below.

[0013] The above summary is provided solely for the purpose of summarizing some exemplary embodiments described herein. Since these embodiments are merely examples, they should not be construed as narrowing the scope of the disclosure in any way. It will be understood that the scope of the disclosure encompasses many potential embodiments in addition to those summarized above, some of which will be described in further detail below. [Brief explanation of the drawing]

[0014] While specific exemplary embodiments have been described above, please refer to the accompanying drawings, which are not necessarily drawn to scale. Some embodiments may include fewer or more components than those shown in the drawings.

[0015] [Figure 1A] Figure 1A shows a cross-section of young oceanic crust and related structures located near a theoretical mid-ocean ridge that may give rise to and / or host abiotic hydrogen production. [Figure 1B] Figure 1B shows a cross-section of young oceanic crust and related structures located near a theoretical mid-ocean ridge that may give rise to and / or host abiotic hydrogen production. [Figure 1C] Figure 1C shows a cross-section of young oceanic crust and related structures located near a theoretical mid-ocean ridge that may give rise to and / or host abiotic hydrogen production. [Figure 1D] Figure 1D shows a cross-section of young oceanic crust and related structures located near a theoretical mid-ocean ridge that may give rise to and / or host abiotic hydrogen production. [Figure 2] Figure 2 shows an exemplary cross-section of serpentinized ultramafic rock. [Figure 3] Figure 3 shows a map indicating the locations of suitable olivine and pyroxene localities around the world. [Figure 4A]Figure 4A provides an exemplary flowchart showing a series of operations performed by a system, according to some exemplary embodiments described herein, to promote the isolation of carbon dioxide, the generation of hydrogen gas, and the production of magnetite and magnesite using a single reactor. [Figure 4B] Figure 4B provides an exemplary flowchart showing a series of operations performed by a system, according to some exemplary embodiments described herein, to promote the isolation of carbon dioxide, the generation of hydrogen gas, and the production of magnetite / magnesite using multiple reactors. [Figure 5] Figure 5 shows an exemplary flowchart for promoting the isolation of carbon dioxide, the generation of hydrogen gas, and the production of magnetite / magnesite, according to some exemplary embodiments described herein. [Figure 6] Figure 6 shows an exemplary flowchart for the collection and preparation of raw rock for a reaction, according to some exemplary embodiments described herein. [Figure 7] Figure 7 shows an exemplary flowchart for processing the rock remaining after the reaction of carbon dioxide and / or water, according to some exemplary embodiments described herein. DETAILED DESCRIPTION

[0016] Hereinafter, some exemplary embodiments will be described in more detail with reference to the accompanying drawings, which show some, but not necessarily all, embodiments. Since the invention described herein can be embodied in many different forms, the invention should not be limited to the embodiments described herein, but rather these embodiments are provided so that this disclosure meets the applicable legal requirements.

[0017] [Overview] As described above, the Applicant has recognized that although ferroan igneous rocks and / or ultramafic igneous rocks (or, more broadly, ores containing high iron-content garnets and pyroxenes, such as ores containing garnets and pyroxenes) can play the role of an economic geological source of hydrogen, be used as a natural source and catalyst for hydrogen and magnetite generation, and have great theoretical potential for use in carbon sequestration, the optimal processes and kinetics of these reactions have not been rigorously evaluated and have not been optimized. Specifically, no process steps have been developed that improve both carbon sequestration and the production of hydrogen, magnetite, magnesite, and / or other minerals without the formation of alternative (in some cases, harmful) mineral phases from these types of rocks, such as serpentine and asbestos.

[0018] Furthermore, to the Applicant's knowledge, there have been no prior attempts to use an optimized chemical process for carbon mineralization to improve the rate of hydrogen and magnetite production or to control the chemical species of the resulting reaction products (e.g., suppress the formation of serpentine and asbestos).

[0019] In various embodiments disclosed herein, ores rich in garnets and pyroxenes are used to isolate carbon dioxide and produce hydrogen, magnetite, and other rare metals economically (and with a net zero to negative carbon footprint) through sequential carbonation and serpentination reactions in a controlled environment. Accordingly, the Applicant has developed an engineering process that utilizes the potential of ores rich in garnets and pyroxenes to isolate carbon dioxide mainly as magnesite or other carbonate minerals and liberate hydrogen, magnetite, and / or other desired minerals / rare metals using sequential reactions. The Applicant has further recognized that additional process steps applied to ores rich in garnets and pyroxenes can facilitate the concentration and recovery of precious or rare metals (e.g., nickel, cobalt, chromium, lithium, and rare earth elements) required for applications such as renewable energy and energy storage.

[0020] The applicant has found that the serpentinization reaction process can be favored by first removing most of the magnesium olivine from the olivine mineral phase and increasing the grinding of mineral particles by inducing the described chemical reaction, thereby improving the chemical activity and corresponding reaction rate of the reaction between water and iron olivine and / or iron silicate. In this way, the iron olivine and / or iron silicate in the igneous rock are concentrated and / or become less obscured by adjacent minerals such as magnesium olivine. This process benefits the reaction in two ways: firstly, by increasing the surface area of ​​the iron olivine and / or iron silicate exposed to the reaction; and secondly, by pre-concentrating the selected reactants (iron-rich olivine (iron olivine) or pyroxene (iron silicate)). Accordingly, in one or more embodiments, the magnesium olivine and / or enstatite are at least partially removed before the iron olivine and / or iron silite are reacted with water.

[0021] Some key differentiating factors that demonstrate the value of exemplary ex situ engineering embodiments of producing hydrogen, magnesite, magnetite, and critical metals through this pathway include: 1) the enormous geological scalability of such embodiments after the “serpentinization” process has been optimized to produce the desired products (hydrogen, magnetite, and rare metals) rather than alternative mineral phases such as serpentinite or asbestos; 2) the potential to permanently and verifiable sequestration of CO2 in a mineralized form, thereby producing hydrogen, magnetite, and rare metals in a carbon-negative process; and 3) the potentially scalable price point of “green” or “golden” hydrogen (i.e., carbon-negative hydrogen), magnetite, and rare metals, which can be largely offset by considering other value streams generated using the concept of quarrying (i.e., the sale of aggregates or higher-value utilization of magnesite).

[0022] Although a higher-level description of the operation of exemplary embodiments is provided above, specific details relating to the configuration of such exemplary embodiments are provided below.

[0023] [Serpentinization reaction and carbonation reaction] The disclosures herein provide one or more embodiments of systems and methods for promoting the formation of hydrogen, magnetite, and / or other desired minerals by serpentinization reactions involving olivine and pyroxene-rich ores commonly found in mafic igneous rocks and / or ultramafic igneous rocks, or by serpentinization reactions of any other rock aggregates containing such olivine and pyroxene-rich ores. Table 1 below shows typical serpentinization reactions involving iron olivine (FeSiO4) and / or iron siliceous (Fe2Si2O6). Iron olivine is an iron-rich end-component mineral phase of the olivine solid solution series and is abundantly found in olivine-rich ores. Iron siliceous is an iron-rich end-component of the orthorhombic pyroxene solid solution series and coexists with pyroxene-rich ores. Iron olivine and iron silicate are typically found together in mafic and ultramafic igneous rocks. Under certain conditions, water reacts with iron olivine and iron silicate to produce magnetite (Fe3O4), silica (SiO2), and hydrogen gas (H2) in favorable stoichiometric ratios. In each case, 2 moles of hydrogen gas are produced from 3 moles of iron olivine or iron silicate mineral.

[0024] [Table 1]

[0025] In one or more embodiments, the disclosed systems and methods may also promote the sequestration of gaseous carbon dioxide as mineralized carbonates by carbonation reactions involving magnesium-rich end components of olivine and pyroxene-rich ores typically found in mafic and / or ultramafic rocks. Table 2 below shows typical carbonation reactions involving magnesium olivine (Mg2SiO4) and enstatite (MgSiO6), as well as the possibility of carbonation during reactions with antigorite (Mg3Si2O5(OH)4), which can form as an associated mineral phase in natural systems where fluid conditions are not ideal for magnesite formation. Magnesium olivine is a mineral phase that is a magnesium-rich end component of the olivine solid solution series coexisting with olivine-rich ores. Enstatite is a mineral phase that is a magnesium-rich end component of the orthorhombic pyroxene solid solution series coexisting with pyroxene-rich ores. Antigorite is an exemplary mineral phase that coexists with serpentinite. Under certain conditions, carbon dioxide reacts with olivine and enstatite, and / or other associated mineral phases (e.g., antigorite) to produce at least magnesium carbonate (MgCO3) and silica (SiO2) in favorable stoichiometric ratios. The reaction of antigorite with carbon dioxide has been shown to further produce stoichiometric amounts of water, exhibiting a serpentinization reaction that occurs in nature where pH, Eh, temperature, pressure, and fluid chemistry cannot be optimized. In the case of an ideal carbonization reaction involving olivine and enstatite, 2 moles of carbon dioxide gas are converted to magnesium carbonate (magnesite) for every 1 mole of olivine or enstatite mineral.

[0026] [Table 2]

[0027] In nature, and as mentioned above, the serpentinization and carbonization reactions do occur, but only as part of a variety of reactions occurring subsurface or across diverse environmental conditions on the Earth's surface. Consequently, environmental conditions are often variable, and the reaction rates and pathways are far from ideal. Thus, natural reactions are based on the diverse (and often dynamic, i.e., time-varying) pH, oxygen fugacity, temperature, pore water chemical composition, gas chemical composition, and pressure found in nature, especially subsurface. The numerous reactions that occur in nature, and their potential pathways, lead to the formation of diverse and complex chemical properties and mineral aggregates, but they do not predict any particular combination of usable reaction products. Instead, natural systems evolving over time and under diverse reaction conditions produce complex (and often heterogeneous) composites of various mineral aggregates and reaction products that do not follow the ideal reactions described above, or they reach thermodynamic equilibrium more slowly.

[0028] Regarding the mineralogical composition and chemical properties of olivine and pyroxene, olivine is a solid solution series between magnesium silicate (magnesium olivine) and iron silicate (iron olivine) (X2SiO4, where X=Mg 2+ or Fe 2+ ) and pyroxene (i.e., orthorhombic pyroxene) is a solid solution series between magnesium silicate (enstatite) and iron silicate (ferrosilicate) (X2Si2O6, where X=Mg 2+ or Fe 2+In olivine-rich deposits, iron olivine and iron siliceous are typically trace elements, generally in concentrations ranging from 6% to 20%, with lower concentrations being more common in nature. Consequently, the thermochemical activity of iron olivine and iron siliceous is relatively low compared to that of magnesium olivine or enstatite, respectively. Therefore, olivine or pyroxene obtained from quarries is crushed and reacted with water under favorable reaction conditions (i.e., controlled temperature, pressure, Eh, pH, and fluid composition), after which the serpentinization reaction proceeds at a relatively slow rate due to the relatively low thermochemical activity and consequently slow rate of the reaction with iron olivine or iron siliceous. Nevertheless, upon completion of the reaction, the reaction produces magnetite, silica, and hydrogen (from the reaction of iron olivine or iron silite with water), and the magnetite, silica, and hydrogen can be separated (magnetically or gravimetrically) from the magnesium olivine, enstatite, or magnesite. However, a mixture of olivine minerals (magnesium olivine and iron olivine) and pyroxene minerals (enstatite and iron silite) constitutes a nearly "ideal" mixture, which is extremely rare in nature. However, in an ideal mixture, the chemical activity changes linearly with respect to the mole fraction and is approximately equal to the mole fraction. Therefore, the chemical activity and reaction rate of large quantities of olivine and pyroxene from bulk ore can be improved, particularly by pre-concentrating large quantities of iron-rich end components of both the olivine and pyroxene solid solution series.

[0029] [Off-site carbon dioxide sequestration and hydrogen production] In various embodiments intended herein, carbon dioxide may be mineralized, and hydrogen, magnesite, magnetite, and critical metals may be produced economically (and with an overall neutral to net-negative carbon footprint) by an engineering system that causes sequential reactions in the manner shown in the flow diagrams in Figures 4A and 4B and described in relation to the flowcharts shown in Figures 5, 6, and 7.

[0030] Figure 4A shows a flow chart of one embodiment 400' of a system that facilitates the generation of hydrogen gas and magnetite from rocks containing a mixture of olivine minerals (e.g., iron olivine and magnesium olivine) and pyroxene minerals (e.g., iron silite and enstatite). The source of olivine and / or pyroxene-rich ore 402 can be fed into or introduced into a crusher or grinder 406 that reduces the size of the received ore into smaller fragments. In one or more embodiments, optionally, a washer 404 may be used to wash the ore with water or a weakly acidic solution to remove impurities from the ore and prepare the ore for the carbonation reaction. The crushed or ground rock is then introduced into a sieve 408 or other similar separator that separates the rock into a pre-selected particle size range. In one or more embodiments, the sieve or its grid may be of different sizes, although they may have sizes that allow particles of 150 microns, 80 microns, or even 45 microns to pass through. In at least one embodiment, the crushed rock is in powder form or has a powdery particle size range. The rock that does not pass through the sieve is returned to the crusher or grinder 406 via the recycling loop 410, where it may be further reduced in size. A portion of the rock having particles of any size within a pre-selected particle size range of the sieve 408, such as 150 microns, 80 microns, 45 microns, or somewhere in between, is then supplied to or introduced into the reactor 412.

[0031] The reactor 412 may be a rotary kiln, a toroidal fluidized bed, a fluidized bed, or another reactor known to those skilled in the art. The reactor 412 may have an inlet for receiving ore (or ore particles) and at least one outlet through which the remaining ore after the reaction inside the reactor 412 can be removed. The reactor 412 may further have at least one additional inlet through which one or more of carbon dioxide or water can be introduced into the reactor 412. The reactor 412 may be operable to react the carbon dioxide that entered the reactor 412 through the at least one additional inlet with the ore placed inside the reactor 412 at a first temperature and for a first residence time to produce magnesium carbonate. The reactor 412 may also be operable to react water that enters the reactor through at least one additional inlet (which may be the same inlet as the inlet into which carbon dioxide enters the reactor 412, or a different inlet) with the ore placed inside the reactor 412 at a second temperature and for a second residence time to produce magnetite and hydrogen gas.

[0032] In the first reaction step, carbon dioxide is introduced into reactor 412 along with the crushed / ground rock. Either before or after the rock is placed in reactor 412, water (about 10 liters per kilogram) may be applied to the crushed / ground rock by a washer 404 (either by spraying or washing). Wetting the pulverized rock with water allows gaseous CO2 to dissolve in carbonic acid (H2CO3) on the wet surface of the mineral particles, thereby improving the reactivity of the magnesium olivine minerals in the rock with carbon dioxide. In at least one embodiment, the pH of the water applied to the ground rock may be between about 4.8 and about 6.5. Water within this pre-selected pH range further promotes the reaction between carbon dioxide and the magnesium olivine minerals. During this first reaction step, the reactor is operated at a pre-selected temperature (above 90°C) and pressure (above about 5 bar) to promote the carbonation reaction of the olivine minerals found in the rock. In one or more embodiments, the reactor 412 is operated at a temperature between about 100°C and about 400°C and a pressure between about 5 bar and at least 100 bar (e.g., about 40 bar, about 50 bar, about 75 bar, or even 100 bar); however, the upper limit of the pressure can be extended to significantly higher pressures if the reactor 412 and its associated components can withstand such pressures. By increasing the pressure in this way, the carbonation reaction being promoted at this stage of the process is correspondingly promoted. In other embodiments, the operating pressure of reactor 412 may be as low as 35 bar, 30 bar, 25 bar, 20 bar, 15 bar, 10 bar, 5 bar, or even lower (about 1 bar), and even then, although the reaction rate is considerably low, the intended carbonation reaction can still be promoted. As shown in Table 2 above, magnesium carbonate (MgCO3) and silicon dioxide (SiO2) are produced as reaction products by the reaction of carbon dioxide with magnesium olivine (Mg2SiO4).In this way, using mafic and / or ultramafic olivine minerals, CO2 is permanently sequestrated in the form of an insoluble magnesium carbonate mineral lattice, which is a solid that may be useful as a raw material and can be placed in landfills, seas, lakes, or otherwise easily stored. By reacting crushed / ground rocks containing olivine with carbon dioxide under favorable temperature, pressure, Eh, and pH conditions, the olivine can be converted to magnesite after reaction with carbon dioxide.

[0033] This first reaction step favorably promotes the pulverization of the raw rock and better prepares the remaining rock for the second reaction step described below. However, in some embodiments, this first reaction step may not be performed, and instead, the raw rock may be simply pulverized, which in itself prepares the raw rock for the second reaction step, as illustrated in the section on embodiments below. Of course, in other embodiments, the raw rock may not need to go through the first pulverization step, but instead may be treated only initially using the first reaction step described herein, which in itself promotes the pulverization of the raw rock and, consequently, prepares the raw rock for a more effective reaction in the second reaction step described below. Both the pulverization of the raw rock and the carbonation reaction that occurs during the first reaction step favorably deposit the remaining rock for the reaction steps described in the sections below. Therefore, in various scenarios, various combinations of pulverization and the first reaction step may be used, based on the desired results of a given embodiment.

[0034] In the second reaction step, water is then introduced into reactor 412 along with the crushed / ground rock, which in some embodiments may still contain magnesium carbonate and silicon dioxide from the first reaction step, iron olivine minerals and / or iron siliceous minerals from the original crushed / ground rock, and other minerals / ores found in the original crushed / ground rock. In some embodiments, the magnesium carbonate and silicon dioxide from the first reaction step may be separated from the residual iron silicate phase based on their respective densities. In one or more embodiments of these processes, the water added to reactor 412 may have low oxygen fugacity (for example, this water may be obtained from a municipal sewage treatment plant, groundwater, geothermal water, mine water, another industrial water source, or by reacting municipal water (i.e., “tap water”) on a copper bed at a temperature above 125°C, or by another mechanism) and may have a pH between about 8.3 and about 11.1 (a specific pH may be achieved artificially, such as by adding sodium bicarbonate to the water, or may be obtained naturally, such as when water in such a pH range is found in certain water sources and wastewater sources). During this second reaction step, the reactor is operated at a pre-selected temperature and pressure (about 1 bar to 20 bar) to promote the serpentinization of iron olivine and / or iron siliceous minerals in the rock. In one or more embodiments, reactor 412 is operated at a temperature in the range of about 80°C to about 400°C. As shown in Table 1 above, the reaction of water with iron olivine (Fe2SiO4) and / or iron silite (Fe2Si2O6) produces hydrogen gas and various mixtures of nitrogen (N2), carbon dioxide (CO2), silicon dioxide, and magnetite (Fe3O4) as reaction products. The molecular and isotopic composition of the hydrogen formed during this out-of-situ process is determined by the reaction temperature conditions (e.g., about 175°C) and the composition of the initial water, where the fractionation coefficient (α) between H2O and H2 follows the fractionation coefficient observed by a standard geothermal meter.The hydrogen gas is sent to the gas separator 414 along with any other gases in reactor 412, such as unreacted carbon dioxide (CO2), sulfur dioxide (SO2), or dihydrogen sulfide (H2S), or inert gases from the first reaction step (e.g., nitrogen (N2), argon (Ar)). The gas separator 414 may be a membrane unit, pressure swing adsorption, or cryogenic separation unit capable of separating the hydrogen gas from other gases that may also be present in reactor 412, such as atmospheric gas. The gas separator 414 may be connected to at least one outlet of reactor 412 and fluidically connected, and may be configured to separate the hydrogen gas from the gases exiting reactor 412 through the at least one outlet.

[0035] In at least one embodiment, any gases that may be present in reactor 412 before the second reaction can be evacuated before the second reaction, for example, by evacuating reactor 412. If these impurity gases (e.g., N2 or CO2) are not present in reactor 412, the only gas present after the second reaction step may be hydrogen gas formed as a result of the serpentinization reaction with water. In such a case, gas separator 414 may not be required to separate the hydrogen gas as a product. After the second reaction step, magnesium carbonate, silicon dioxide, magnetite, and any remaining rock / unreacted ore can be removed from reactor 412. In some embodiments, magnesium carbonate (i.e., magnesite) and silicon dioxide (i.e., quartz) can be separated from iron silicate and other mineral phases before the materials are introduced into reactor 412. Magnetite is a useful product / raw material for the iron industry (particularly valuable in the direct production of reduced iron) and can be recovered from magnesium carbonate, silicon dioxide, and the remaining rock / ore by, for example, magnetic separation or other density separation techniques. Using the magnetic separator 416, magnetite can be selectively attracted by using one or more magnets, thereby physically removing the magnetite from other nonmetallic ores. In one or more embodiments, the solid products such as magnetite, magnesium carbonate, silicon dioxide, and the remaining unreacted ore / rock can be further crushed or ground (not shown in Figure 4A) to facilitate the removal of magnetite particles from other solids in the magnetic separator 416 or to perform secondary recovery of other mineral or metal-rich phases. The hydrogen gas separated from the gas separator 414 and the magnetite recovered via the magnetic separator 416 are useful products whose formation and recovery from mafic and / or ultramafic rocks are facilitated by the sequential carbonization and serpentinization reactions disclosed herein.

[0036] The remaining magnesium carbonate, silicon dioxide, and unreacted rock / ore (with carbon permanently sequestrated in the mineral phase) can be used as aggregate material and / or placed in landfills or disposed of by other means. In one or more embodiments, magnesium carbonate and silicon dioxide can be separated (based on heavy liquid separation or other gravity separation, density separation techniques such as the runoff method) and removed from the remaining rock / gangue material (gangue: an aggregate of associated mineral phases such as phosphates, sulfides, and aluminum oxides). As will be further described below, magnesium carbonate (or magnesite) is useful in the manufacture of pharmaceuticals, agricultural lime (to neutralize acidification caused by the use of fertilizers), fertilizers, ceramics, and ceramic bricks, as well as a flux used in steelmaking. Magnesite can also be used as a partial lime substitute, which allows for lower carbon emissions, due to the lower temperatures required for the production of magnesium oxide (MgO) compared to calcium oxide (CaO) for cement production. Furthermore, magnesite can be used as a carbon-negative concrete filler and as a substitute for cement or aggregate in concrete.

[0037] In one or more embodiments, instead of filling in or otherwise using the majority of the magnesium carbonate, silicon dioxide, and unreacted rock / ore, the rock and / or gangue material from the first reaction step is further processed to separate and remove specific useful components from the rock and / or gangue material. For example, high concentrations of certain precious metals (e.g., nickel, cobalt, chromium, rare earth elements) in mafic and ultramafic rocks are further concentrated in this “slag” material. In at least one embodiment, a high metal concentrate, including but not limited to phosphates, aluminum oxides, precious metals, and other gangue minerals, may be separated from the remaining rock / ore by, for example, heavy liquid separation or other gravity separation in separator 418, or by a chute method. By gravity separation, various metals and other useful components are ground into fine particles and separated based on their individual specific gravities.

[0038] As shown in Figure 4A, both the first and second reactions may occur in the same reactor 412, which may be a rotary kiln, fluidized bed, toroidal bed, or other reactor as described above, in which case the reactions may be carried out sequentially, and all products may be separated upon completion of both reactions. In one or more embodiments (not shown in Figure 4A), the reaction products (i.e., magnesium carbonate and silicon dioxide) may be separated after the first reaction step and before the second reaction step using heavy liquid separation or other gravity separation, or established density separation techniques such as the chute method. In other embodiments, as shown in Figure 4A, the reaction products remain in the reactor during the second reaction step. Even if the reaction products are not physically separated, the thermochemical activity and reaction rate of olivine and / or ferrosilite increase in proportion to the newly exposed surface area of ​​the olivine and / or ferrosilite minerals. In other words, the reactivity of the serpentinization reaction with respect to iron olivine and / or iron silicate minerals proceeds according to the increased mole fraction of iron olivine and / or iron silicate in the solid solution (i.e., the number and / or extent of alternative side reactions are reduced). With respect to the upper limit of iron olivine and / or iron silicate that has been completely separated or exposed (e.g., using heavy liquid separation or other gravity separation or established density separation techniques such as the run-through method), the thermochemical activity of the powder material will approach that of a single pure phase mineral or a mixture of iron olivine and / or iron silicate mineral phases. Therefore, the first reaction step, which involves the reaction of magnesium olivine with carbon dioxide, increases the thermochemical driving force for the second reaction step, which is the serpentinization / hydration reaction of iron olivine and / or iron silicate with water, by reducing the availability of magnesium olivine and increasing the exposed surface area of ​​the iron olivine and / or iron silicate minerals. The former increases the kinetic rate by bringing the thermochemical activity closer to that of the pure compound, while the latter improves the chemical activity by increasing the surface area available for the reaction.

[0039] Figure 4B shows a flow diagram of another embodiment 400'' of a system that promotes the production of hydrogen gas and magnetite from a protolith containing a mixture of olivine (ferroolivine and magnesium olivine) minerals and / or pyroxene (ferrosilite and enstatite) minerals. The flow diagram of Figure 4B is similar to the flow diagram of Figure 4A, except that the first reaction step occurs in the first reactor 412' and the second reaction step occurs in the second reactor 412''. The first reactor 412' promotes the carbonation reaction between magnesium olivine minerals and carbon dioxide. A homogeneous or pre-selected crushed / ground ore is fed into the first reactor 412' from a sieve 408 or other particle size separator. Carbon dioxide is pumped into the first reactor 412' in the stoichiometric ratios listed above to promote the carbonization reactions listed in Table 2. After the first reaction has occurred, the magnesium carbonate and silicon dioxide products, along with the unreacted iron olivine and / or iron silicate, and other remaining ore, are sent to the second reactor 412''.

[0040] Continuing with Figure 4B, the second reactor 412'' facilitates the serpentinization reaction between the iron olivine and / or iron siliceous mineral phases and water (or vapor). The reaction products and remaining rock / ore from the first reactor 412' are introduced into the second reactor 412''. Water is pumped into the second reactor 412'' at the stoichiometric ratio described above (more than 20 liters per 1 kg of rock) to facilitate the serpentinization reaction listed in Table 1. After the second reaction has occurred, the reactor gas, including the hydrogen gas generated during the second reaction step, is sent to or transferred to the gas separator 414 as described above with respect to Figure 4A. Similarly, the solid reaction products, including magnesium carbonate, silicon dioxide, and magnetite, are sent to the magnetic separator 416 along with the unreacted ore / rock as described above with respect to Figure 4B. As described above, the embodiments shown in Figures 4A and 4B are similar, except that two reactors 412' and 412'' are used instead of one reactor 412. Note that the system configuration in Figure 4B provides a semi-continuous method in that separate processing vessels, such as reactors 412' and 412'', are dedicated to different parts of the method.

[0041] Figures 5, 6, and 7 show flowcharts of various embodiments that facilitate the generation of hydrogen gas, magnetite, magnesite, and rare metal resources from mafic and ultramafic igneous rocks containing mixtures of olivine (ferroolivine and magnesium olivine) minerals and pyroxene (ferrosilite and enstatite) minerals. As described above in relation to Figure 3, olivine and / or pyroxene-rich ores can be found in many locations around the world. In block 502, such olivine and / or pyroxene-rich ores can be extracted from geological sites containing high concentrations of such rocks in one or more of these areas. Figure 6 illustrates this rock acquisition operation in more detail. As shown in block 602, olivine and / or pyroxene-rich proto-rocks can be extracted by any method known to those skilled in the art, such as underground mining, open-pit mining, quarrying, outcrop quarrying, and utilization of waste (i.e., mine tailings). The raw rock can be transported, for example, by barge, train, or truck to a facility for further processing the rock. In one or more embodiments, the raw rock may be processed near the site from which the rock is collected. In block 606, the raw rock may be processed by crushing and / or grinding the rock into smaller fragments. Such grinding helps to make the size uniform or nearly uniform and also helps to expose minerals such as olivine (magnesium olivine and iron olivine) and pyroxene (enstatite and iron silite) contained within the rock. If the rock is processed near the geological site from which it originates, the processed rock may then be transported to a facility having a system for further extracting hydrogen, magnetite, and other useful products from the ore according to the methods disclosed herein (not shown in Figures 5 and 6). In block 608, the crushed and / or ground raw rock may be further processed by sieving or other methods to separate the rock according to size. In one or more embodiments, the crushed and / or ground rock may be washed with water or a weakly acidic solution to remove dust, mud, or other impurities from its surface. As shown in block 604, such washing may be performed before the rock is crushed and / or ground and may benefit from agitation.

[0042] Next, in block 610, the crushed and / or ground rock is introduced into the reactor, where it reacts with carbon dioxide and water to produce magnesium carbonate and hydrogen gas, along with other products, in stoichiometric ratios via the carbonation reaction described in Table 2. In block 610, the crushed / ground rock can be transported to and from the reactor by conveyor, machinery, etc., and introduced into the reactor. The weakly acidic aqueous solution described above can be applied to the outer surface of the rock, for example, by washing, spraying, or immersion. Such application may be before or after the rock is deposited in the reactor. The oxygen-containing air inside the reactor can be evacuated from the sealed reactor containing the rock (for example, by applying a vacuum to the reactor) or purged with a reaction gas (e.g., N2) before the reaction begins. Returning to Figure 5, block 504 shows that carbon dioxide (CO2) is introduced into the reactor to initiate the first reaction step. As described above, carbon dioxide may be in gaseous or supercritical form. To ensure that carbon dioxide does not limit the carbonation reaction and to take advantage of the increased reactivity observed to occur at high pressures of CO2 and / or supercritical CO2, a stoichiometric amount of carbon dioxide is added to the reactor relative to the amount of rock (and in particular the concentration of olivine in the rock). In block 504, the reactor is operated for a first residence time at one or more pre-selected temperatures and pressures, as described above, to allow sufficient reaction of carbon dioxide with the olivine mineral to produce magnesium carbonate and silicon dioxide reaction products. At the end of the first residence time, the gas phase from the reactor may be evacuated, for example by applying a vacuum or by a gas purging operation, to remove excess unreacted carbon dioxide and any other gases generated by the carbonation reaction in the first reaction step.

[0043] Continuing with Figure 5, in block 506, water is introduced into the reactor after the first residence time. In one or more embodiments, the water is hypoxic fugacity water prepared or obtained as described in more detail above. Again, to ensure that the water does not limit the serpentinization reaction, a stoichiometric amount of water (more than about 20 liters per kg of rock) is added relative to the amount of rock in the reactor (and in particular the concentration of iron olivine and / or iron silite in the rock). In block 506, the reactor is operated for a second residence time at one or more pre-selected temperatures and pressures, as described above, to allow the water to react sufficiently with the iron olivine and / or iron silite minerals (which, by the first reaction step, have come to have additional exposed surface area and more optimized chemical activity) to produce at least hydrogen gas and magnetite reaction products.

[0044] In block 508, the gas phase is removed from the reactor during or upon completion of the second reaction stage. This gas phase, rich in hydrogen gas (and possibly containing small amounts of trace gases, such as N2, Ar, and CO2), can be further purified by a gas separator 414 (as shown in Figures 4A and 4B). The gas separator 414 may be a pressure swing adsorption unit, a membrane separation unit, a cryogenic separation unit, or any other gas separation unit known to those skilled in the art. If the gas phase is not exhausted from the reactor between the first and second reaction stages, some of the other gases, such as carbon dioxide and / or reaction gases, may contaminate the hydrogen gas generated in the reactor by the serpentinization reaction in the second reaction stage.

[0045] In block 510, the remaining rock inside the reactor may be further processed, and magnesium carbonate / magnesite, iron oxide / magnetite, silicon dioxide, any remaining ore, and / or slag material may be removed from the reactor. These operations are described in detail with reference to Figure 7. Block 702 shows that the remaining rock inside the reactor may be removed for further processing. Such removal may include removal by mechanical devices that pick up, scrape, or feed the material by gravity from the reactor into a container or onto a conveyor. In particular, in block 702, solid reaction products (i.e., magnesite, magnetite, etc.), remaining ore, and any slag material may be sent to a magnetic separator 416 (as shown in Figures 4A and 4B) to separate the magnetite from the other material by the magnetic attraction of magnetosensible iron oxide to a magnetic field (see block 704). The solid material removed from the reactor in block 702 may undergo further crushing and / or grinding to produce a fine powder that facilitates the removal of its useful components (not shown in Figures 5 and 7). In block 706, any precious or rare metals that have become more concentrated in the remaining ore and / or gangue material (aggregates of associated mineral phases such as phosphates, sulfides, and aluminum oxides) after the removal of magnetite may be separated and removed based on heavy liquid separation or other gravity separation or density separation techniques such as the runoff method; an example of gravity separation using a gravity separator is shown in 480. Finally, as shown in block 708, the remaining rock, including the remaining magnesium carbonate, silicon dioxide, and any unreacted rock / ore (with carbon permanently sequestered in the mineral phases), may be used as aggregate material and / or placed in a landfill or disposed of by other means. As described above, in some embodiments, magnesium carbonate and silicon dioxide may be separated and removed from the remaining rock / gangue material (gangue: an aggregate of associated mineral phases such as phosphates, sulfides, and aluminum oxides) for separate disposal (based on heavy liquid separation or other gravity separation, or density separation techniques such as the drain method).

[0046] Figures 5, 6, and 7 illustrate operations performed in various exemplary embodiments. It will be understood that each flowchart block, and each combination of flowchart blocks, can be implemented by various means. A flowchart block supports a combination of means for performing a particular function and a combination of actions for performing a particular function. In some embodiments, some of the above operations may be modified or further extended. Furthermore, in some embodiments, additional optional actions may be included. Modifications, extensions, or additions to the above operations may be performed in any order and in any combination.

[0047] [Examples] In one example, ultramafic ore was reacted with carbon dioxide to sequester carbon in a magnesium carbonate mineral phase, and ultramafic rock was reacted with water to generate hydrogen gas and produce magnetite. This example was carried out in three stages: 1) rock preparation; 2) water preparation; and 3) reaction process, each of which is described in more detail below. As part of the analysis of the entire system and method, the composition of the ore (i.e., olivine (magnesium olivine and iron olivine) minerals and pyroxene (enstatite and iron siliceous) minerals), the reaction conditions to which the ore was targeted, and the characteristics of the carbonation / serpentinization reaction products were evaluated. For example, with respect to the composition of the ore, the mass, mineralogical composition, and geochemical composition of the bulk rock were evaluated by optical mineralogy, powder X-ray diffraction (XRD), and inductively coupled plasma mass spectrometry (ICP-MS), and the abundance of relevant components (e.g., iron olivine, iron siliceous, FeO, MgO) was evaluated.

[0048] In the rock preparation phase, ultramafic aggregate material, primarily consisting of rock particles approximately 1 cm in size, was collected from four operational quarries (i.e., two in Pennsylvania, one in Virginia, and one in Kentucky). The ultramafic aggregate material was first crushed (i.e., lightly crushed / ground) with a rock hammer, and then with a Spex Ball mill. The powder material was then sieved using a grid designed to allow 150-micron, 80-micron, and 45-micron particles to pass through sequentially. This allowed for experimentation with at least three different particle sizes. Another material, homogenized olivine mineral, was also purchased from a California scientific supplier. This olivine material was homogenized in size and composition, with a uniform grain size of approximately 100 microns.

[0049] In the water preparation stage, three preparations were carried out. First, low-oxygen fugacity, high-pH water was obtained by adding sodium bicarbonate, and / or sodium hydroxide or potassium hydroxide, to tap water to adjust the pH of the water to three levels: 8.3, 9.7, and 11.1. As will be understood by those skilled in the art, oxygen fugacity (fO2) is a measure of the amount of oxygen available to react with elements having multiple valence electron states, such as iron and carbon. High oxygen fugacity indicates a high chemical potential of oxygen in water. Reducing the oxygen fugacity of water can be achieved in various ways (e.g., by using a low-oxygen fugacity water supply such as city sewage, groundwater, mine water, or other wastewater flow). One simple and reliable way to produce low-oxygen fugacity water is to use a bed of copper scraps heated to 125°C and pass water through this bed to reduce the oxygen fugacity of the water (i.e., reduce the amount of reactive oxygen species in the water). Such a method was used in this embodiment. Secondly, brine was obtained by adding salt (sodium chloride) to tap water to create saline solutions ranging from 0.1 per mille to 4.5 per mille. In preparation for the carbon mineralization experiment, dilute HCl in a mixture of distilled water and sodium acetate buffer was used to adjust the pH of the brine to between approximately 4.8 and 6.5.

[0050] For the reaction process, a single batch reactor (made of 316 stainless steel) was designed and constructed to carry out the carbonation and serpentinization reactions in both batch and sequential configurations. All reactions were carried out as “batch” reactions (i.e., closed systems) within this sealed stainless steel reaction vessel, except for a fluid sampling port that was opened periodically. For each experiment, an entire sample (approximately 250 grams) was selected and sliced ​​into two equally sliced ​​portions of approximately 125 grams each, which were placed in the airtight stainless steel reaction vessel. In preparation for the introduction of carbon dioxide into the vessel, distilled water was weakly acidified with dilute hydrochloric acid and sodium acetate buffer, and then mixed with salt (sodium chloride) to create a 0.1 to 4.5 per mille NaCl salt solution at ambient oxygen fugacity. This prepared aqueous solution was then sprayed onto the pulverized rock introduced into the reaction vessel. The prepared aqueous solution provided a moist surface to enhance the reactivity of carbon dioxide with olivine during the subsequent carbonation reaction.

[0051] In the first reaction step, the goal was to sequestrate carbon dioxide through a carbonation reaction between the introduced carbon dioxide and the magnesium olivine (and enstatite) in the ore. The acidic brine prepared as described above was applied to the pulverized rock containing the magnesium olivine minerals before the moistened (i.e., sprayed with the aqueous solution as described above) pulverized rock was placed in the stainless steel reaction vessel. Prior to the introduction of carbon dioxide, the reaction vessel was evacuated by applying a vacuum using a mechanical rough pump to remove ambient oxygen-containing air from the reaction vessel. Other embodiments include flushing the vessel with an inert gas (e.g., N2) or a reaction gas (e.g., CO2 or a mixture thereof) to remove the air.

[0052] Next, carbon dioxide gas, or a mixture of carbon dioxide gases, for example, a gas mixture of carbon dioxide and nitrogen in a 4:1 ratio, was introduced at room temperature at an initial pressure of 2 bar (i.e., twice atmospheric pressure); in other embodiments of this disclosure, other ratios may be used as the CO2 to N2 ratio. The carbon dioxide used was, for example, ultra-high purity carbon dioxide with a purity of carbon dioxide in the gas exceeding 99.9%, but in various embodiments, a mixture with lower purity CO2 may be used. Next, the temperature inside the reaction vessel was raised to 100°C, 150°C, 200°C, 250°C, 300°C, and 400°C, the temperature controlled by an external band heater and measured by a standard Omega K-wire thermocouple. At each temperature, the gas phase pressure was measured via a sampling port using a standard Omega 0-100 psi pressure gauge. At each temperature, gas aliquots were measured using a Stanford Research Systems residual gas analyzer ("quadrupole mass spectrometer") and an SRI gas chromatograph equipped with a thermocouple detector. The total pressure of hydrogen was calculated by taking the product of the ratio of hydrogen gas measured using the residual gas analyzer and / or gas chromatograph, and the pressure compared to atmospheric pressure, and assuming PV=nRT.

[0053] As the temperature was increased from 150°C to 300°C, the kinetic rate of carbon mineralization appeared to increase by approximately 1.6 times; however, between 300°C and 400°C, the further increase in the rate of CO2 mineralization over a reaction time of approximately 18 hours in batch experiments was not statistically significant. Next, while maintaining a constant temperature of 250°C, the pressure of carbon dioxide was increased to 5 bar, 10 bar, 25 bar, and 50 bar. At each step, the gas phase pressure was monitored via the sampling port (to ensure that the sample pressure was within the range of the available pressure gauge) using a standard Omega 0-100 psi pressure gauge on an attached expansion volume. For each pressure, after depressurizing by expanding the sampling port into a pre-empted sample chamber, gas aliquots were also measured using an SRS quadrupole mass spectrometer and an SRI gas chromatograph equipped with a thermocouple detector. The rate of carbon mineralization appeared to increase by approximately 2.7 times at 250°C and pressures between 5 and 50 bar.

[0054] Preliminary results from the first reaction stage indicate that the rate of carbon dioxide mineralization increases as the ore grain size decreases. Based on measurements of CO2 pressure and concentration, and the mass of mineralized rock in the reaction vessel, a 23% improvement in the reduction of CO2 concentration was observed between 150 microns and 25 microns when the temperature was kept constant at 250°C. Although the removal of air is thought to improve the rate of carbon mineralization, at least one operation without removing air / oxygen from the reaction vessel at the start of the first reaction stage did not appear to have a significant effect on the carbonization reaction. Increasing both the temperature and pressure of the reaction conditions increased the rate of CO2 mineralization up to at least 300°C and 50 bar over a reaction time of approximately 18 hours in batch experiments. Based on the plateau of reaction pressure, these conditions are expected to approach thermodynamic equilibrium between 12 and 18 hours in batch conditions, although variability is observed across a wide range of experimental conditions (i.e., generally shorter times at higher temperatures and pressures).

[0055] While the temperature was increased from 100°C to 300°C at a constant pressure of 10 bar, the mineralization rate increased from 14% added mass to 27% (after 24 hours in the batch reactor), indicating a 92% increase in the mass of rock produced by carbon mineralization. While the pressure was increased from 1 bar to 50 bar at a constant temperature of 250°C, the mineralization rate increased from 4.1% added mass to 18.9% (after 24 hours in the batch reactor), indicating a 4.6-fold increase in the mass of rock produced by carbon mineralization. Rotary kiln, fluidized bed, and toroidal bed processes have not been evaluated in this process, but despite the expected similar effects of temperature and pressure as in the batch process, both the reaction rate and the overall efficiency of mineralization can be expected to increase significantly compared to the batch process.

[0056] In another experiment, supercritical carbon dioxide was used in the reactor during the first reaction step. Preliminary results showed that supercritical CO2 injected into the reactor at 10 bar and 250°C reached the pressure plateau 4.5 hours (18.8%) faster than gaseous CO2. Thus, carbon sequestration by this disclosed out-of-situ carbonation reaction can be maximized or promoted, taking into account temperature and pressure, in addition to other cost-intensive variables such as energy input, material handling, and chemical processing costs. After the first reaction step, the weight of the solid contents of the reactor was weighed. The total carbon mineralization was measured based on the mass increase between 39.3 grams (15.7%) at 150°C and 5 bar and 101.6 grams (40.6%) at 300°C and 50 bar, which was verified using an optical microscope. As predicted based on the stoichiometry of the carbonation reaction, which leads to the prior enrichment of iron-rich iron-silica ((iron olivine, and / or iron siliceous) phases prior to the second reaction step, magnesite (i.e., magnesium carbonate), which was not observed in the initial experimental material, was identified.

[0057] In the second reaction step, the goal was the liberation of hydrogen by a serpentinization / hydration reaction between the introduced water and the remaining olivine and / or ferrosilite (a mixture from four natural samples and one pure olivine preparation sample) in the ore. Prior to the introduction of water for the serpentinization reaction, the reaction vessel was evacuated by applying a vacuum using a mechanical rough pump to remove the remaining introduced carbon dioxide-containing air from the reaction vessel. Next, the low-oxygen fugacity (i.e., negative Eh value or negative potential), high pH (i.e., a pH range between 8.3 and 11.1 using sodium bicarbonate, or sodium hydroxide or potassium hydroxide), and brine (sodium chloride (NaCl) at approximately 0.1 to 4.5 per mille), prepared as described above, were introduced into the reaction vessel containing the remaining ore (i.e., unreacted ore consisting of the iron silicate phase, magnesium carbonate, silicon dioxide, residual olivine, pyroxene, and other associated mineral phases) at room temperature and ambient atmospheric pressure.

[0058] The initial gas phase pressure was measured and recorded via a sampling port using a standard Omega 0-100 psi pressure gauge. Next, the temperature inside the reaction vessel was increased to 50°C, 100°C, 150°C, 200°C, 250°C, 300°C, and 400°C, with the temperature controlled by an external band heater and monitored using an Omega K-wire thermocouple. At each temperature step, the gas phase pressure was measured via a sampling port using a standard Omega 0-100 psi pressure gauge. At each temperature, gas aliquots were measured using a Stanford Research Systems residual gas analyzer ("quadrupole mass spectrometer") and an SRI gas chromatograph equipped with a thermocouple detector. The total pressure of hydrogen (and other gases) was calculated by productting the percentage of hydrogen gas measured using the residual gas analyzer and / or gas chromatograph with the pressure compared to atmospheric pressure, assuming PV=nRT.

[0059] Preliminary results from the second reaction step indicated that the rate of hydrogen evolution increased as the ore grain size decreased. Based on measurements of H2 partial pressure over an 18-hour period, the H2 yield increased 5.2 times between the 50°C and 100°C temperature steps when a constant pressure of 10 bar was maintained. Based on measurements of H2 partial pressure over an 18-hour period, the H2 concentration yield increased 7.3 times between the 100°C and 400°C temperature steps when a constant pressure of 10 bar was maintained. The H2 yield increased with pressure, but not as much as with temperature. Based on measurements of H2 partial pressure over an 18-hour period, the H2 yield increased by 31% between 1 bar and 5 bar at a constant temperature of 250°C, and by 1.8 times between 5 bar and 40 bar at a constant temperature of 250°C. Compared to the serpentinization reaction without a preceding two-step carbonation reaction, the reaction rate of the serpentinization reaction, when carried out at a constant pressure of 20 bar, increased by 21% at 150°C and up to 87% at 250°C compared to experiments conducted at 100°C. This change is thought to be due to the pre-concentration of the iron silicate mineral phase, along with the crushing of the ore brought about by carbonation, which promotes the initial decomposition of the rock / ore. The maximum increase in H2 yield was 1.8 times the yield observed at 100°C, and was observed in the 200°C temperature step after density separation of SiO2 and MgCO3 from the denser iron silicate by laboratory flush method; the total amount of H2 produced in this step was 0.576 mol H2 / kg. It was shown that the purity of the generated hydrogen gas improved with increasing temperature steps; various mixtures of N2, Ar, and trace amounts of CO2 were observed at both the 50°C and 100°C temperature steps, while at temperatures above 150°C, the CO2 content was less than 5% in the non-condensable fragments, with the exception of one sample at 400°C which yielded 6.7% CO2.

[0060] Along with the composition (%), the total pressure of the hydrogen gas formed by the reaction increases with increasing temperature, indicating that the reaction rate and overall yield of hydrogen production gradually increase with increasing temperature. This result is theoretically expected, and it distinguishes the hydrogen produced by the exemplary embodiments described herein from the hydrogen produced by the natural system, which consists of CO2 and HCO3 below the Earth's surface. - Alternatively, the generation of carbon in other forms may begin to react with hydrogen at approximately 150°C, thereby "short-circuiting" the production of carbon-negative hydrogen by the formation of abiogenic methane via the Sabatier reaction (i.e., CO2 + 4H2 → CH4 + 2H2O), where CO2 can be available as gaseous CO2 or released from the dissolved inorganic carbon phase in the pore fluid by the following reaction: H + +HCO3→CO2+H2O.

[0061] The disclosed two-step reaction was compared with two base-case single-step reactions. The first base-case comparison was a single-step reaction at pH 6.0, with the temperature increased from room temperature to 50°C, 100°C, 150°C, 200°C, 250°C, 300°C, and 400°C. The maximum H2 yield at this pH was less than 0.011 mol H2 / kg at 400°C, which was expected based on weakly acidic conditions. The second base-case comparison was a single-step reaction at pH 8.0, with the temperature increased from room temperature to 50°C, 100°C, 150°C, 200°C, 250°C, 300°C, and 400°C. At this pH, with the pressure kept constant at 20 bar, the H2 yield in this one-step reaction ranged from below the detection limit at 50°C after 18 hours, to 0.051 mol H2 / kg at 100°C, and a maximum of 0.349 mol H2 / kg at 400°C. For comparison, the highest value observed at 400°C in the one-step base case was 69.6% lower than the highest yield in the two-step reaction described above. Thus, hydrogen gas production by this disclosed in-situ serpentinization reaction can be maximized or promoted by preventing interactions between H2 and unstable carbon (i.e., CO2), taking into account temperature and pressure, in addition to other cost-intensive variables such as energy input, material handling, and chemical processing costs.

[0062] After the sequential first and second reaction stages (i.e., carbonation and serpentinization) were completed in the reaction vessel, the mass (i.e., weight), mineralogical composition, and geochemical composition of the remaining bulk rock were measured by optical mineralogy and ICP-MS to assess the abundance (or absence) of relevant components (e.g., iron olivine, iron silicate, FeO, MgO). Although visible olivine and pyroxene were still observed along with small amounts of serpentinite, the amount of magnetite observed was significantly higher in the sequential reaction (i.e., the first and subsequent second reaction stages) than when the reaction was carried out without prior enrichment of iron olivine and / or iron silicate minerals and control of reaction conditions such as pH, hypoxia control, and temperature (11% to 171% based on the mass of separable magnetic components). Magnetite yield increased by 11% between the 50°C and 100°C temperature steps, and by approximately 13% between the 100°C and 150°C temperature steps. Furthermore, when a constant pressure of 10 bar was maintained for 18 hours, 1.7 times more magnetite was recovered magnetically compared between the 300°C and 100°C steps. Based on the stoichiometry of the reaction and these observations, it is clear that the increase in magnetite formation (as predicted from the stoichiometric serpentinization reaction) is linked to and closely related to the increase in hydrogen formation. These results support stoichiometric modeling of both carbon dioxide mineralization (by carbonation) and hydrogen formation (by serpentinization / hydration reaction). Thus, magnetite can be formed as a byproduct of hydrogen formation / evolution (or vice versa, depending on the chosen business method).

[0063] Further analysis of residual materials identified high metal concentrates in the gangue ("mineral slag"), including phosphates, aluminum oxides, and other undefined solids. For example, lanthanum (one of the rare earth elements) showed an average concentration of 8.2 ppm in bulk samples of ultramafic rock from a Pennsylvania quarry and an average concentration of 187.1 ppm in the residual gangue (representing approximately 2%–4% of the total material, mainly aluminum oxides, phosphates, and sulfides). Similarly, the concentrations of nickel and cobalt were 133.9 ppm and 78.2 ppm in bulk samples of ultramafic rock from the same Pennsylvania quarry, and 1426 ppm and 976.8 ppm in the residual gangue (mainly aluminum oxides and sulfides). Separation of these metal concentrates can be achieved by heavy liquid separation or other gravity separation, or by drainage methods, or by density separation techniques such as other methods known to those skilled in the art.

[0064] The overall results demonstrate that, in the pursuit of carbon-neutral, or even carbon-negative, hydrogen production, the sequential carbonation and serpentinization reaction steps disclosed herein yield multiple reaction products (e.g., magnetite, rare earth elements, and other rare metals) that have economic and social value in the pursuit of a low-carbon economy, in addition to carbon sequestration and hydrogen generation. Furthermore, although various conditions exist under which each reaction can be accelerated, these differ only slightly depending on the different rock content, and therefore the reactions are generally stable under the aforementioned conditions across various sources of ultramafic and mafic rocks.

[0065] As briefly described above, several reaction products have been identified from the stepwise, sequential carbonation and serpentinization reactions disclosed herein. In particular, four reaction products have the potential to be economically viable if enhanced or made possible by the steps, procedures, and reaction conditions described herein, which enhance the crushing of rocks and the thermodynamic driving force toward ideal "carbonation" and serpentinization / hydration reactions. In addition to the economic viability of these reaction products, there may be rights to revenues associated with the production of these reaction products, such as tax credits, sales of carbon credits, and tax incentives. The four products include magnesite / aggregate, (net carbon-negative) "green" or "golden" hydrogen, magnetite, and rare metals, each of which is described further below.

[0066] [Magnesite] The controlled, off-situ production of magnesite (magnesium carbonate) by promoting "water-rock" serpentinization / hydration reactions involving mined, quarried, or discarded (e.g., mine tailings) mafic or ultramafic rocks and products provides an economical and carbon-neutral (and therefore carbon-negative) pathway for the formation of scalable magnesite and rock aggregates. This process can also economically increase the volume and mass of rock (stoichiometric evaluations of suitable mafic / ultramafic ores suggest that the mass can increase by 34% to over 60% (or 0.34 kg to over 0.60 kg per kg of rock, or 340 kg to over 600 kg per metric ton of rock), while experimental results suggested an increase from 0.104 kg / kg (at 300°C, 50 bar in bulk rock obtained from a Pennsylvania quarry) to 0.237 kg / kg (at 300°C, 50 bar in a pure olivine test sample). These values ​​are expected to increase further compared to the original material introduced into the batch reactor by transferring the rock from the batch to a dynamic reaction process (e.g., rotary kiln, fluidized bed, toroidal bed, or other similar process).

[0067] As disclosed, water having a pH between approximately 4.8 and 6.5 can be mixed with carbon dioxide under controlled conditions (e.g., atmospheric or oxidative conditions) to chemically decompose the magnesium-rich silicate (i.e., olivine) portions of mafic and ultramafic rocks. This reaction can be accelerated at a temperature between approximately 150°C and approximately 300°C-400°C (although our experiments showed a plateau in mineralization at 300°C) and a pressure of at least 50 bar to a maximum to produce magnesite. This carbonation process permanently sequesters carbon dioxide through the precipitation of the magnesite mineral phase and other carbonate minerals, which can be used directly or as rock aggregate.

[0068] The successful conversion of magnesium silicate to magnesium carbonate and other carbonate minerals also makes it possible to remove most of the rock fragments (according to the density separation technique described above), which can then be separated from the residual iron silicate or separated before the serpentinization / hydration reaction. The step of enriching the iron silicate phase may further enrich rare metals (e.g., nickel, cobalt, rare earth elements) in other mineral forms (e.g., aluminum oxide, phosphates, and sulfides). This carbonation process was first carried out so that the reaction products of magnetite and hydrogen gas could be produced more easily and in larger quantities by sequential serpentinization reactions without forming a secondary / competitive phase, thereby facilitating grinding.

[0069] The importance of producing scalable and carbon-negative (or carbon-neutral) magnesium carbonate (magnesite) is directly related to the many current uses of magnesite, including but not limited to pharmaceutical applications, agricultural lime and fertilizers (to neutralize acidification caused by fertilizer use), raw materials for ceramics and ceramic bricks, and fluxes used in steelmaking. Magnesite can also be used as a partial lime substitute, enabling lower carbon emissions, which are achieved by the lower temperature required to produce magnesium oxide (MgO) compared to calcium oxide (CaO). Furthermore, magnesite can be used as a carbon-negative concrete filler, as well as a substitute for cement or aggregate in concrete.

[0070] [Green / Golden Hydrogen] Hydration reactions involving iron silicate (e.g., iolite, iron silicerite) can be used to produce "green" (i.e., carbon neutral) or "golden" (i.e., carbon negative) hydrogen off-site from olivine and / or pyroxene-rich ores such as mafic and ultramafic rocks, which have been mined, quarried, or are in waste flows. In one or more embodiments of the systems and methods disclosed herein, the out-of-situ production of carbon-negative hydrogen relates to a two-reaction step / step process, in which: (1) carbon dioxide is first introduced in a gaseous or supercritical state into crushed rock (less than about 150 microns) moistened with an aqueous preparation having a pH between about 4.8 and about 6; (2) water having hypoxic fugacity (e.g., obtained from urban sewage, geothermal water, or other industrial water applications, or produced by reacting tap water on a copper bed at 125°C) and a pH between 8.3 and about 11.1 over a temperature range between about 60°C and about 400°C (this particular pH is achieved by adding sodium bicarbonate, or sodium hydroxide or potassium hydroxide to the water, such water pH can be found in natural water sources and wastewater).

[0071] In the first reaction step, the removal of most of the magnesium component from the pulverized or crushed rock increases the chemical (reaction) potential of the iron-rich portion in the second reaction step. Stoichiometric calculations suggest that the chemical activity can increase by up to eightfold, but experiments have observed an improvement of nearly twofold; it is expected that the chemical activity and rate can be further increased by transitioning from a batch process to a dynamic process. In fact, the rate of hydrogen production is significantly higher (nearly 70% higher) than the rate of hydrogen production in the method of reacting iron-rich silicate minerals without a precursor step of carbon dioxide mineralization, compared to a base case suitable for the spontaneous reaction or other one-step engineered reaction processes.

[0072] A key advantage of the various embodiments disclosed herein is that the systems and methods of such embodiments can be deployed for out-of-situ operation almost anywhere in the world, due to the vast and widespread reserves of mafic and ultramafic rocks, and the availability of water and chemicals for modifying the pH and Eh of the water. Conversely, hydrogen production by more common methods, such as natural gas reforming, is often limited by other carbon-intensive constraints, particularly the availability of natural gas. Even if the generated carbon dioxide is sequestered, this hydrogen would be considered "blue," rather than "green" or "golden."

[0073] [Magnetite] Controlled off-site magnetite production by facilitating the "water-rock serpentinization" reaction in mined, quarried, or wastewater-rich olivine and pyroxene-rich ores and other materials provides an economical and carbon-neutral (and therefore carbon-negative) pathway for magnetite production, while enabling corresponding carbon dioxide sequestration through carbonate mineralization. Although the carbonation and serpentinization reactions themselves occur naturally, embodiments of the systems and methods disclosed herein relate to facilitating magnetite production by sequentially ordering these reactions in a controlled off-site environment and limiting alternative and undesirable chemical reactions that may produce serpentinite, brucite, or asbestos.

[0074] In various embodiments disclosed herein, the out-of-situ production of magnetite relates to a two-reaction step / step process, in which: (1) carbon dioxide is first introduced in a gaseous or supercritical state in the presence of crushed rock (less than about 150 microns) moistened with an aqueous preparation having a pH between about 4.8 and about 6.5; (2) water having a low oxygen fugacity and a pH between 8.3 and about 11.1 (this particular pH is achieved by adding sodium bicarbonate, or sodium hydroxide or potassium hydroxide to the water, although such water pH can be found in natural water sources and wastewater) is introduced over a temperature range between about 80°C and about 400°C. A two-step reaction at temperatures exceeding 300°C improves magnetite recovery by approximately 1.7 times compared to a low-temperature and suitable base case. Furthermore, the removal of most of the magnesium component from the pulverized or crushed rock in the first reaction step / stage increases the chemical (reaction) potential of the iron-rich portion in the second reaction step / stage (e.g., by approximately 23% to 800%), thereby increasing the thermodynamic driving force for magnetite formation several times over. Consequently, the formation of desirable mineral products such as magnetite and hydrogen is increased compared to the random or undesirable mineral species commonly formed in nature. In fact, the rate of magnetite formation is significantly increased, and the formation of these specific target chemical species is more reliable than the formation of those specific chemical species by reacting iron-rich silicate minerals without a precursor step of carbon dioxide mineralization, or by reacting both CO2 and water together (as occurs in nature) (e.g., reduced formation of serpentinite, brucite, or asbestos).

[0075] The direct reduction of iron (DRI) process is the only commercially viable low-carbon emission steelmaking process and a pioneer in steelmaking. The DRI process requires high-grade iron ore (over approximately 67% iron), which is scarce in natural iron ore worldwide. This limited access to magnetite (or other similarly iron-rich mineral facies) restricts the potential to produce iron or steel using the DRI process, a crucial pathway for reducing carbon emissions in the steel industry. The systems and methods disclosed herein can generate large quantities of high-grade iron ore (magnetite) due to the abundant production of mafic and ultramafic rocks, which comprise over 10% of continental crust and the majority of oceanic crust. Furthermore, carbon sequestration tax credits and / or carbon credit sales related to magnesite production may be added to the magnetite production of these systems and methods. Accordingly, the embodiments disclosed herein could increase carbon credits as well as the availability of high-grade iron ore for the steel industry, which could also lead to the "greening" of the steel industry worldwide. Notably, the simultaneous co-production of magnesite, magnetite, and hydrogen gas (at a single physical site) also satisfies the three requirements of the steelmaking process (i.e., iron-rich iron ore, reducing gas species / hydrogen, and magnesite flux).

[0076] [Rare metals] High concentrations of certain relatively rare metals (e.g., nickel, cobalt, chromium, and rare earth elements) in mafic and ultramafic rocks can be released off-site and more easily recovered through sequential carbon sequestration / carbonation and "water-rock" serpentinization reactions involving mined, quarried, or discarded mafic or ultramafic rocks / ores. These rare, and sometimes strategically important, metals are crucial for renewable energy and energy storage and are often obtained from the mining of weathered or processed minerals in more energy-intensive steps (i.e., dehydrating asbestos back into dolomitic olivine). However, the disclosed systems and methods provide an economical and carbon-neutral (or even carbon-negative) pathway for the production of these rare metals, while also enabling carbon sequestration through the mineralization of carbon dioxide. The reaction of magnesium olivine with gaseous or supercritical carbon dioxide chemically decomposes these magnesium-rich silicate minerals while simultaneously sequestering carbon from carbon dioxide, whereas the reaction of iron olivine and / or iron silite with water chemically decomposes iron-rich silicate minerals while simultaneously producing magnetite and hydrogen gas. As these minerals decompose, the remaining rare metals are concentrated in the remaining unreacted ore and gangue (i.e., aluminosilicates, phosphates, associated oxides, clay, etc.). Consequently, the reaction rates and total metal recovery rates (i.e., high concentrations in the starting compositions) of one or more embodiments disclosed herein are significantly higher than those of natural chemical weathering of mafic and ultramafic rocks. Furthermore, the concentration of rare metals in gangue increases, reducing the carbon footprint of the "mining" or recovery (and derivative uses in mobility and energy storage) of these precious metals. Therefore, sequential carbonation and serpentinization reactions can essentially provide carbon-negative mining of rare and strategically important metals.

[0077] [Conclusion] Many modifications and other embodiments of the inventions described herein will be conceivable to those skilled in the art, benefiting from the teachings shown in the above description and the accompanying drawings. Therefore, it should be understood that the invention is not limited to the specific embodiments disclosed, and that modifications and other embodiments are intended to be included within the scope of the appended claims. Furthermore, while the above description and the accompanying drawings illustrate exemplary embodiments in relation to specific exemplary combinations of elements and / or functions, it should be understood that different combinations of elements and / or functions may be provided by alternative embodiments without departing from the scope of the appended claims. In this regard, combinations of elements and / or functions different from those explicitly described above are also contemplated, for example, as described in part of the appended claims. Certain terms are used herein, but they are used only in a general and descriptive sense and are not intended to be limiting.

[0078] (Note) (Note 1) A method for sequestrating carbon and producing hydrogen and magnetite from rocks, A step of obtaining an ore containing olivine or pyroxene, The steps include introducing the ore into a reactor capable of operating at a temperature exceeding the ambient temperature and a pressure exceeding atmospheric pressure, A step of introducing carbon dioxide into the reactor at a first temperature for a first residence time and reacting it with the ore to produce magnesium carbonate, A step of introducing water into the reactor at a second temperature for a second residence time and reacting it with the ore to produce magnetite and hydrogen gas, The step of removing the hydrogen gas from the reactor, The steps include removing the remaining ore from the reactor, including, method.

[0079] (Note 2) The further step includes crushing the ore into smaller fragments before introducing the carbon dioxide into the reactor. The method described in Appendix 1.

[0080] (Note 3) The further step includes washing the ore with water or an acidic solution before crushing the ore into smaller fragments. The method described in Appendix 2.

[0081] (Note 4) The process further includes the step of sieving the ore before introducing it into the reactor, thereby allowing ore particles up to a predetermined size to pass into the reactor, The step of introducing the ore into the reactor includes the step of introducing only a portion of the ore having particles up to the pre-selected size into the reactor. The method described in any one of the appendices 1 to 3.

[0082] (Note 5) The aforementioned pre-selected size includes sizes ranging from approximately 25 microns to approximately 150 microns. The method described in Appendix 4.

[0083] (Note 6) The further step includes removing at least a portion of the magnesium carbonate from the reactor before introducing the water into the reactor, The method described in any one of the appendices 1 through 5.

[0084] (Note 7) The water has a pH between approximately 8.3 and approximately 11.1. The method described in any one of the appendices 1 through 6.

[0085] (Note 8) The further step includes passing the water through a heated bed of copper scraps to reduce the oxygen fugacity of the water before introducing it into the reactor. The method described in any one of the appendices 1 through 7.

[0086] (Note 9) The further step includes, before introducing the carbon dioxide into the reactor, applying an acidic solution to the ore to be introduced into the reactor. The method described in any one of the appendices 1 through 8.

[0087] (Note 10) The further step includes removing oxygen from the reactor before introducing the carbon dioxide into the reactor. The method described in any one of the appendices 1 through 9.

[0088] (Note 11) The carbon dioxide introduced into the reactor is gaseous carbon dioxide or supercritical carbon dioxide. The method described in any one of the appendices 1 through 10.

[0089] (Note 12) At least one of the first temperature and the second temperature is 400°C or lower. The method described in any one of the appendices 1 through 11.

[0090] (Note 13) At least one of the first temperature and the second temperature is 300°C or lower. The method described in Appendix 12.

[0091] (Note 14) At least one of the first temperature and the second temperature is 250°C or lower. The method described in Appendix 13.

[0092] (Note 15) The carbon dioxide pressure inside the reactor during the first residence time is approximately 5 bar or more. The method described in any one of the appendices 1 through 14.

[0093] (Note 16) The carbon dioxide pressure inside the reactor during the second residence time is approximately 1 bar or more. The method described in any one of the appendices 1 through 15.

[0094] (Note 17) The pressure of carbon dioxide inside the reactor during the second residence time is approximately 5 bar or more. The method described in Appendix 16.

[0095] (Note 18) The pressure of carbon dioxide inside the reactor during the second residence time is approximately 10 bar or more. The method described in Appendix 17.

[0096] (Note 19) The pressure of carbon dioxide inside the reactor during the second residence time is approximately 20 bar or more. The method described in Appendix 18.

[0097] (Note 20) The pressure of carbon dioxide inside the reactor during the second residence time is approximately 40 bar or more. The method described in Appendix 19.

[0098] (Note 21) The further step includes separating the magnetite from the remaining ore. The method described in any one of the appendices 1 through 20.

[0099] (Note 22) The further step includes separating at least one of nickel, cobalt, lithium, chromium, or rare earth elements from the remaining ore. The method described in any one of the appendices 1 through 21.

[0100] (Note 23) A method for sequestrating carbon and producing hydrogen and magnetite from rocks, A step of obtaining an ore containing olivine or pyroxene, The steps include introducing the ore into a first reactor capable of operating at a temperature exceeding the ambient temperature and a pressure exceeding atmospheric pressure, A step of introducing carbon dioxide into the first reactor at a first temperature for a first residence time and reacting it with the ore to produce magnesium carbonate, The step of sending the remaining ore to the second reactor, The steps include introducing water into the second reactor at a second temperature and for a second residence time to react with the remaining ore to produce magnetite and hydrogen gas, The steps include removing the hydrogen gas from the second reactor, The steps include removing the remaining ore from the second reactor described above, including, method.

[0101] (Note 24) The further step includes crushing the ore into smaller fragments before introducing the carbon dioxide into the first reactor. The method described in Appendix 23.

[0102] (Note 25) The further step includes washing the ore with water or an acidic solution before crushing the ore into smaller fragments. The method described in Appendix 24.

[0103] (Note 26) The process further includes the step of sieving the ore before introducing it into the first reactor, thereby allowing ore particles up to a predetermined size to pass into the first reactor, The step of introducing the ore into the first reactor includes the step of introducing only a portion of the ore having particles up to the pre-selected size into the first reactor. The method described in any one of the appendices 23 to 25.

[0104] (Note 27) The aforementioned pre-selected size includes sizes ranging from approximately 25 microns to approximately 150 microns. The method described in Appendix 26.

[0105] (Note 28) The further step includes separating at least a portion of the magnesium carbonate from the remaining ore before sending the remaining ore to the second reactor, The method described in any one of the appendices 23 to 27.

[0106] (Note 29) The water has a pH between approximately 8.3 and approximately 11.1. The method described in any one of the appendices 23 to 28.

[0107] (Note 30) The further step includes passing the water through a heated bed of copper scraps to reduce the oxygen fugacity of the water before introducing it into the second reactor. The method described in any one of the appendices 23 to 29.

[0108] (Note 31) The further step includes applying an acidic solution to the ore to be introduced into the first reactor before introducing the carbon dioxide into the first reactor, The method described in any one of the appendices 23 to 30.

[0109] (Note 32) The further step includes removing oxygen from the first reactor before introducing the carbon dioxide into the first reactor. The method described in any one of the appendices 23 to 31.

[0110] (Note 33) The carbon dioxide introduced into the first reactor is gaseous carbon dioxide or supercritical carbon dioxide. The method described in any one of the appendices 23 to 32.

[0111] (Note 34) At least one of the first temperature and the second temperature is 400°C or lower. The method described in any one of the appendices 23 to 33.

[0112] (Note 35) At least one of the first temperature and the second temperature is 300°C or lower. The method described in Appendix 34.

[0113] (Note 36) At least one of the first temperature and the second temperature is 250°C or lower. The method described in Appendix 35.

[0114] (Note 37) The carbon dioxide pressure inside the first reactor during the first residence time is approximately 5 bar or more. The method described in any one of the appendices 23 to 36.

[0115] (Note 38) The carbon dioxide pressure inside the second reactor during the second residence time is approximately 1 bar or more. The method described in any one of the appendices 23 to 37.

[0116] (Note 39) The pressure of carbon dioxide inside the second reactor during the second residence time is approximately 5 bar or more. The method described in Appendix 38.

[0117] (Note 40) The pressure of carbon dioxide inside the second reactor during the second residence time is approximately 10 bar or more. The method described in Appendix 39.

[0118] (Note 41) The pressure of carbon dioxide inside the second reactor during the second residence time is approximately 20 bar or more. The method described in Appendix 40.

[0119] (Note 42) The pressure of carbon dioxide inside the second reactor during the second residence time is approximately 40 bar or more. The method described in Appendix 41.

[0120] (Note 43) The process further includes the step of separating the magnetite produced from the remaining ore removed from the second reactor, The method described in any one of the appendices 23 to 42.

[0121] (Note 44) The process further includes separating at least one of nickel, cobalt, chromium, or rare earth elements from the remaining ore removed from the second reactor. The method described in any one of the appendices 23 to 43.

[0122] (Note 45) A method for producing hydrogen and magnetite from rocks, A step of obtaining an ore containing olivine or pyroxene, The steps include crushing the ore into smaller fragments, The steps include introducing the ore into a reactor capable of operating at a temperature exceeding the ambient temperature and a pressure exceeding atmospheric pressure, A step of introducing water into the reactor at a specific temperature and for a specific residence time and reacting it with the ore to produce magnetite and hydrogen gas, The step of removing the hydrogen gas from the reactor, The steps include removing the remaining ore from the reactor, including, method.

[0123] (Note 46) The further step includes washing the ore with water or an acidic solution before crushing the ore into smaller fragments. The method described in Appendix 45.

[0124] (Note 47) The process further includes the step of sieving the ore before introducing it into the reactor, thereby allowing ore particles up to a predetermined size to pass into the reactor, The step of introducing the ore into the reactor includes the step of introducing only a portion of the ore having particles up to the pre-selected size into the reactor. The method described in Appendix 45 or 46.

[0125] (Note 48) The aforementioned pre-selected size includes sizes ranging from approximately 25 microns to approximately 150 microns. The method described in Appendix 47.

[0126] (Note 49) The water has a pH between approximately 8.3 and approximately 11.1. The method described in any one of the appendices 45 to 48.

[0127] (Note 50) The further step includes passing the water through a heated bed of copper scraps to reduce the oxygen fugacity of the water before introducing it into the reactor. The method described in any one of the appendices 45 to 49.

[0128] (Note 51) The aforementioned specific temperature is 400°C or lower. The method described in any one of the appendices 45 to 50.

[0129] (Note 52) The aforementioned specific temperature is 300°C or lower. The method described in Appendix 51.

[0130] (Note 53) The aforementioned specific temperature is 250°C or lower. The method described in Appendix 52.

[0131] (Note 54) The pressure of carbon dioxide inside the reactor during the aforementioned specific residence time is approximately 1 bar or more. The method described in any one of the appendices 45 to 53.

[0132] (Note 55) The pressure of carbon dioxide inside the reactor during the specified residence time is approximately 5 bar or more. The method described in Appendix 54.

[0133] (Note 56) The pressure of carbon dioxide inside the reactor during the aforementioned specific residence time is approximately 10 bar or more. The method described in Appendix 55.

[0134] (Note 57) The pressure of carbon dioxide inside the reactor during the aforementioned specific residence time is approximately 20 bar or more. The method described in Appendix 56.

[0135] (Note 58) The pressure of carbon dioxide inside the reactor during the aforementioned specific residence time is approximately 40 bar or more. The method described in Appendix 57.

[0136] (Note 59) The further step includes separating the magnetite produced from the remaining ore, The method described in any one of the appendices 45 to 58.

[0137] (Note 60) The further step includes separating at least one of nickel, cobalt, lithium, chromium, or rare earth elements from the remaining ore. The method described in any one of the appendices 45 to 59.

[0138] (Note 61) A system for sequestrating carbon and producing hydrogen and magnetite from rocks, Sources of ore containing olivine or pyroxene, A reactor having an inlet for receiving ore particles and at least one outlet, wherein the reactor also has at least one additional inlet into which one or more of carbon dioxide or water are introduced, and the reactor is operable to react carbon dioxide entering the reactor through the at least one additional inlet with the ore to produce magnesium carbonate at a first temperature and for a first residence time, and the reactor is also operable to react water entering the reactor through the at least one additional inlet with the ore to produce magnetite and hydrogen gas at a second temperature and for a second residence time, A gas separator connected to the at least one outlet of the reactor, in fluid communication with the at least one outlet, and configured to separate hydrogen gas from the gas discharged from the reactor through the at least one outlet, Equipped with, system.

[0139] (Note 62) A crusher further comprising a crusher for physically reducing the particle size of the ore introduced into the crusher from the supply source, The system described in Appendix 61.

[0140] (Note 63) The system further includes a sieve that receives ore from the crusher and allows ore particles up to a pre-selected size to pass to the reactor, The inlet for receiving ore particles can be configured to accept only ore particles having a size less than or equal to the pre-selected size from the sieve. The system described in Appendix 62.

[0141] (Note 64) A magnetic separator for receiving the remaining ore from at least one outlet of the reactor, the magnetic separator further comprises a magnetic separator having a magnet for attracting the magnetite and thereby separating the magnetite from the other components of the remaining ore. The system described in any one of the appendices 61 to 63.

[0142] (Note 65) The device further comprises a washing device that applies an acidic solution to the ore particles before the ore particles react with carbon dioxide. The system described in any one of the appendices 61 to 64.

[0143] (Note 66) The system further comprises a separator for separating at least one of nickel, cobalt, chromium, or rare earth elements from the remaining ore portion removed from the reactor. The system described in any one of the appendices 61 to 65.

[0144] (Note 67) The reactor comprises a first reactor into which carbon dioxide is introduced, and a second reactor into which water is introduced, wherein the first reactor is operable to react the carbon dioxide that entered the first reactor through the at least one additional inlet with the ore at a first temperature for a first residence time, and the second reactor is operable to react the water that entered the second reactor with the remaining ore introduced from the first reactor to the second reactor at a second temperature for a second residence time. The system described in any one of the appendices 61 to 66.

Claims

1. A method for sequestrating carbon and producing hydrogen and magnetite from rocks, A step of obtaining an ore containing olivine or pyroxene, The steps include introducing the ore into a reactor capable of operating at a temperature exceeding the ambient temperature and a pressure exceeding atmospheric pressure, A step of introducing carbon dioxide into the reactor at a first temperature for a first residence time and reacting it with the ore to produce magnesium carbonate, A step of introducing water into the reactor at a second temperature for a second residence time and reacting it with the ore to produce magnetite and hydrogen gas, The step of removing the hydrogen gas from the reactor, The steps include removing the remaining ore from the reactor, Includes, The water has a pH between 8.3 and 11.

1. method.

2. A method for sequestrating carbon and producing hydrogen and magnetite from rocks, A step of obtaining an ore containing olivine or pyroxene, The steps include introducing the ore into a reactor capable of operating at a temperature exceeding the ambient temperature and a pressure exceeding atmospheric pressure, A step of introducing carbon dioxide into the reactor at a first temperature for a first residence time and reacting it with the ore to produce magnesium carbonate, Before introducing water into the reactor, the water is passed through a heated bed of copper scraps to reduce the oxygen fugacity of the water. A step of introducing the water into the reactor at a second temperature for a second residence time and reacting it with the ore to produce magnetite and hydrogen gas, The step of removing the hydrogen gas from the reactor, The steps include removing the remaining ore from the reactor, including, method.

3. A method for sequestrating carbon and producing hydrogen and magnetite from rocks, A step of obtaining an ore containing olivine or pyroxene, The steps include introducing the ore into a reactor capable of operating at a temperature exceeding the ambient temperature and a pressure exceeding atmospheric pressure, Before introducing carbon dioxide into the reactor, the ore is washed with an acidic solution. A step of introducing the carbon dioxide into the reactor at a first temperature for a first residence time and reacting it with the ore to produce magnesium carbonate, A step of introducing water into the reactor at a second temperature for a second residence time and reacting it with the ore to produce magnetite and hydrogen gas, The step of removing the hydrogen gas from the reactor, The steps include removing the remaining ore from the reactor, including, method.

4. A method for sequestrating carbon and producing hydrogen and magnetite from rocks, A step of obtaining an ore containing olivine or pyroxene, The steps include introducing the ore into a reactor capable of operating at a temperature exceeding the ambient temperature and a pressure exceeding atmospheric pressure, Before introducing carbon dioxide into the reactor, the step of removing oxygen from the reactor, A step of introducing the carbon dioxide into the reactor at a first temperature for a first residence time and reacting it with the ore to produce magnesium carbonate, A step of introducing water into the reactor at a second temperature for a second residence time and reacting it with the ore to produce magnetite and hydrogen gas, The step of removing the hydrogen gas from the reactor, The steps include removing the remaining ore from the reactor, including, method.

5. A method for sequestrating carbon and producing hydrogen and magnetite from rocks, A step of obtaining an ore containing olivine or pyroxene, The steps include introducing the ore into a reactor capable of operating at a temperature exceeding the ambient temperature and a pressure exceeding atmospheric pressure, A step of introducing carbon dioxide into the reactor at a first temperature for a first residence time and reacting it with the ore to produce magnesium carbonate, A step of introducing water into the reactor at a second temperature for a second residence time and reacting it with the ore to produce magnetite and hydrogen gas, The step of removing the hydrogen gas from the reactor, The steps include removing the remaining ore from the reactor, The steps include separating at least one of nickel, cobalt, lithium, chromium, or rare earth elements from the remaining ore, including, method.

6. The further step includes crushing the ore into smaller fragments before introducing the carbon dioxide into the reactor. The method according to any one of claims 1 to 5.

7. The further step includes washing the ore with water or an acidic solution before crushing the ore into smaller fragments. The method according to claim 6.

8. The process further includes the step of sieving the ore before introducing it into the reactor, thereby allowing ore particles up to a predetermined size to pass into the reactor, The step of introducing the ore into the reactor includes the step of introducing only a portion of the ore having particles up to the pre-selected size into the reactor. The method according to any one of claims 1 to 5.

9. The aforementioned pre-selected size includes sizes between 25 microns and 150 microns. The method according to claim 8.

10. The further step includes removing at least a portion of the magnesium carbonate from the reactor before introducing the water into the reactor, The method according to any one of claims 1 to 5.

11. The carbon dioxide introduced into the reactor is gaseous carbon dioxide or supercritical carbon dioxide. The method according to any one of claims 1 to 5.

12. At least one of the first temperature and the second temperature is 400°C or lower. The method according to any one of claims 1 to 5.

13. At least one of the first temperature and the second temperature is 300°C or lower. The method according to claim 12.

14. At least one of the first temperature and the second temperature is 250°C or lower. The method according to claim 13.

15. The carbon dioxide pressure inside the reactor during the first residence time is 5 bar or more. The method according to any one of claims 1 to 5.

16. The pressure of carbon dioxide inside the reactor during the second residence time is 1 bar or more. The method according to any one of claims 1 to 5.

17. The pressure of carbon dioxide inside the reactor during the second residence time is 5 bar or more. The method according to claim 16.

18. The pressure of carbon dioxide inside the reactor during the second residence time is 10 bar or more. The method according to claim 17.

19. The pressure of carbon dioxide inside the reactor during the second residence time is 20 bar or more. The method according to claim 18.

20. The pressure of carbon dioxide inside the reactor during the second residence time is 40 bar or more. The method according to claim 19.

21. The further step includes separating the magnetite from the remaining ore. The method according to any one of claims 1 to 5.

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