System and method for silicate material production

Abstract

A system for producing a silicate material, the system comprising: a first reactor comprising a first spray nozzle and a first airlock; the first reactor configured to receive a superheated steam; the first reactor configured to receive a first process gas; a second reactor comprising a second spray nozzle and a second airlock; the second reactor configured to receive a steam; and the second reactor configured to receive a second process gas. A method for producing a silicate material, the method comprising: heating a feedstock; disposing the feedstock in a reactor; applying steam to the feedstock to yield a calcium silicate material; cooling the calcium silicate material; applying moisture to the calcium silicate material; and carbonating the calcium silicate material to yield a carbonated silicate material. A calcium silicate material composition comprising: synthetic calcium silicate.

Description

SYSTEM AND METHOD FOR SILICATE MATERIAL PRODUCTIONCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to and the benefit of the filing of U. S. Provisional Patent Application No. 63 / 713,215, entitled "SYSTEMS AND METHODS FOR REACTORS USED IN SYNTHESIS OF CEMENTITIOUS MATERIALS", filed on October 29, 2024, and U. S. Provisional Patent Application No. 63 / 853,384, entitled “SYSTEM AND METHOD FOR SILICATE MATERIAL PRODUCTION, filed on July 29, 2025, and the specification and claims thereof are incorporated herein by reference.BACKGROUND OF THE INVENTIONField of the Invention (Technical Field):

[0002] The present invention relates to systems and method for silicate material production. The present invention also relates generally to the field of production and more specifically to a new and useful system and method for reactors used in synthesis of cementitious materials.Background:

[0003] Traditional cement production relies heavily on rotary kiln reactors, a large cylindrical reactor used to process raw materials such as limestone and clay into clinker, the essential component of cement. The process involves heating these materials to extremely high temperatures, which can be 1350 °C to 1450°C in the burning zone. These temperatures facilitate chemical reactions that form calcium silicates and calcium aluminates, the basis of clinker. However, this process is energy-intensive, typically relying on carbon-heavy fuels such as coal, oil, or natural gas, leading to high energy costs and significant CO2emissions. Additionally, the equipment itself is costly to install and maintaindue to the need for robust refractory linings and precise temperature control, further increasing the overall operational expenses. The combination of high operational temperatures, reliance on non-renewable energy sources, and high capital expenditure make traditional cement production both expensive and environmentally damaging.

[0004] The cement and concrete industries are responsible for approximately 8% of global CO2 emissions. These emissions predominantly arise from the thermal decomposition of limestone (CaCO3), a principal component of Portland cement, and from the high-temperature processing conditions (typically exceeding 1400 °) required to achieve partial melting of cement raw materials during clinker formation. The calcination of limestone releases CO2as a byproduct, in addition to the CO2generated through the combustion of fossil fuels used to maintain these temperatures in conventional kilns.

[0005] Efforts have been made to develop low-carbon alternatives to mitigate the environmental impact of cement production. One approach involves formulating cement with reduced limestone content or alternative chemistries; however, these systems often face long timelines for commercialization due to extensive testing, regulatory approvals, and standardization requirements.

[0006] A more immediately scalable approach to reducing cement-related CO2emissions involves the use of supplementary cementitious material (“SCM") to partially replace conventional Portland cement in mortar and concrete formulations at replacement levels ranging from 1% to 50%, up to 90%. SCMs may contain both natural materials and industrial byproducts. Among the most widely used are blast furnace slag and coal fly ash, which possess pozzolanic or latent hydraulic properties that enhance long-term strength development. However, the supply of these industrial byproduct SCMs is increasingly constrained. As the steel and coal power sectors undergo decarbonization, the production of slag and fly ash has sharply declined. Additionally, many legacy stockpiles are not intended for use in cementitious systems and suffer from inconsistent quality due to inadequate historical storage and poor material traceability.

[0007] The production of conventional Portland cement is an energy-intensive process and a major contributor to global anthropogenic carbon dioxide (CO2) emissions. As part of ongoing efforts to mitigate the environmental impact of cement production, thedevelopment of low-carbon alternatives has received attention. Among these, low calcium cements and carbonation-enabled supplementary cementitious material (“SCM”) have emerged as promising pathways for reducing CO2 intensity.

[0008] Outside of the cement and material production domain, supplementary cementitious materials such as fly ash, and ground granulated blast furnace slag (“GGBFS”) have been widely adopted to partially replace Portland cement in concrete formulations. These materials have long-term viability challenges as their source industry decarbonize or shut-down. For example, coal-fired power plants are the primary source for fly-ash - the emergence and adoption of inexpensive and cleaner energy solutions, such as nuclear, solar, natural gas, geothermal, challenge that industry and longer-term fly ash scarcity. Similarly for slag, as the steel industry decarbonizes, less slag will be available for SCM production. Beyond, these materials face challenges related to inconsistent availability, variable chemical composition, and regional supply limitations. Consequently, supply volatility threatens the scalability of decarbonization strategies that depend on SCMs.

[0009] In response to these limitations, industrial efforts have focused on developing synthetic and engineered SCMs using controlled processing of silicate-rich materials. Examples include calcined kaolinitic clays, vitrified silicate glasses, and carbonated materials derived from industrial waste streams. However, these systems typically require energy-intensive pre-treatment steps such as calcination, mechanochemical activation, vitrification, wet processing, excessive drying, acid-base processing, and in many cases, as it relates to CO2mineralization, the existing solutions exhibit slow carbonation kinetics and low CO2uptake. In some cases, these technologies rely on high-purity CO2streams and extended residence times to achieve sufficient uptake, which further inhibits commercial viability.

[0010] Wollastonite is a naturally occurring calcium silicate mineral (CaSiO3) known for its needle-like morphology, high thermal stability, and low water solubility. It is widely used in ceramics, paints, plastics, and construction materials due to its reinforcing properties, whiteness, and resistance to chemical attack. In ceramics, wollastonite acts as a fluxing agent, improving strength and reducing firing temperatures. In polymers and coatings, it serves as a functional filler, enhancing dimensional stability and mechanical performance.

[0011] Natural wollastonite (CaSiO3) typically forms under metamorphic conditions involving T < 800 °C at deep crustal pressures, particularly in contact or regional metamorphism of impure limestones or dolomitic rocks in the presence of silica.Table 1: Typical Formation ConditionsParameter Range Notes.nn o„.On Formation begins around 400 °C, but well-crystallized Temperature ~ 400 °C to 800 °C „..., „..wollastonite often forms at > 600 °C31 to 5 kbar _........ / d c i >-> ■ *cCommon in skarn environments adjacent to igneous Pressure (v14.5 kPsi to 72.5..... intrusionsJkPsi)

[0012] Synthetic wollastonite is of growing interest due to control over composition, morphology, and performance compared to natural sources. While natural wollastonite often contains impurities such as iron, magnesium, or aluminum oxides, synthetic wollastonite can be engineered to achieve high phase purity, typically in the form of wollastonite-2M (P-CaSiO3) or pseudo-wollastonite (a-CaSiO3), depending on processing conditions. This purity is especially important in applications where material properties like whiteness, thermal stability, or chemical reactivity are critical. In addition, synthetic processing methods allow precise control over particle size, shape, and surface area. This enables the production of nanoscale or acicular wollastonite with enhanced functionality, especially in accelerating mineral carbonation.

[0013] Wollastonite can be synthesized through a variety of techniques, each offering distinct advantages in terms of raw material flexibility, process temperature, product phase, and sustainability. The solid-state reaction method remains a foundational approach, wherein calcium carbonate and silica are mixed and calcined at 900 °C to 1200 °C to yield low temperature wollastonite phases, while pseudo-wollastonite (a-CaSiO3) is synthesized at 1250 °C to 1400°C. Modified wet chemical methods offer enhanced purity and polymorph control by using calcium and silicon salts that undergo solution processing and lower temperature synthesis (about 800 °C to 1200 °C), producing both p- and a-wollastonite. Solution combustion synthesis (“SCS”), using fuel-rich mixtures of metal nitrates and urea, rapidly produces nanostructured wollastonite powders at about 820 °C due to the exothermic self-propagating nature of the reaction. The hydrothermal method,often conducted at 200 °C to 250 °C in autoclaves, leverages calcium hydroxide and waste-derived amorphous silica (e.g., rice husk ash), resulting in the formation of hydrated calcium silicates, which upon calcination enable wollastonite formation under milder thermal conditions. Microwave-assisted synthesis has also been explored, providing rapid volumetric heating and energy efficiency for producing inorganic phases, including nanowollastonite. Emphasizing sustainability, waste-based synthesis routes utilize industrial byproducts such as cement bypass dust and silica fume, sintered at about 1100 °C, to yield wollastonite. Lastly, etching and sonication method offers a novel chemical route to nanowollastonite in which silica is first etched using hydrofluoric acid and then reacts with calcium salts under ultrasonic agitation, producing nanoparticles as small as10 nanometers (“nm”) at ambient temperatures. While recent advances in wet chemistry and hydrothermal methods have enabled lower synthesis temperatures, these approaches often rely on expensive chemical precursors, require batch processing, or yield nanosized products with limited scalability.

[0014] The solid-state reaction route is the most suitable for industrial-scale applications due to its robustness, relative low energy, compatibility with widely available raw materials, and scalability within existing thermal processing infrastructure. However, this method does not directly yield nanosized wollastonite. Instead, it typically produces coarser crystalline particles that require significant post-synthesis milling to achieve fine particle sizes. This additional size reduction step is both costly and energy intensive, which can limit the overall efficiency and economic viability of the process, particularly for applications where high surface area or nanoscale morphology is critical for performance.

[0015] Wollastonite has also emerged as a promising candidate for environmental applications, particularly in the field of soil remediation and carbon capture and storage (“CCS”) through mineral carbonation. Its chemical structure, comprising reactive calcium ions and silicate frameworks, enables it to react with carbon dioxide (CO2) to form stable calcium carbonate (CaCO3) and amorphous silica (SiO2), making it an ideal material for permanent CO2sequestration. The carbonation of wollastonite is exothermic and can proceed efficiently under mild conditions (40 °C to 90 °C, atmospheric to elevated pressures). Nanosized form of wollastonite exhibits higher carbonation reaction rates and more complete carbonation due to increased surface area and absence of passivating silica shells. This property allows wollastonite to be used not only for flue gas carbonationbut also in direct air capture (“DAC”) systems, where its natural abundance, low solubility, and high carbonation capacity (theoretical uptake about 30 wt% to 38 wt% CO2) are advantageous.

[0016] Wollastonite-based DAC carbonation can achieve competitive CO2removal costs, especially when coupled with waste heat or renewable energy inputs. Furthermore, the resulting carbonated material can be utilized in concrete formulations as a supplementary cementitious material (“SCM”), contributing to circular economy and low-carbon construction. These dual roles of permanent CO2sequestration and cement replacement position wollastonite as a multifunctional mineral in sustainable industrial processes.

[0017] In environmental applications, synthetic wollastonite demonstrates significantly higher reactivity toward CO2than its natural counterpart, making it suitable for mineral carbonation, direct air capture (“DAC”), and use as a supplementary cementitious material (“SCM”) after carbonation. Moreover, synthetic production can utilize industrial by-products like steel slag, fly ash, or construction waste as calcium and silica sources, contributing to circular economy goals. Finally, given the geographic limitations and variable quality of natural wollastonite deposits, synthetic production ensures consistent material supply and scalability, positioning it as a critical material in sustainable construction and carbon capture technologies.

[0018] The time required to carbonate wollastonite powder depends on several factors, including particle size, surface area, temperature, CO2concentration, pressure, and the presence of water or steam. Several approaches have been explored to accelerate and enhance the carbonation efficiency of wollastonite, including adjustments to carbonation conditions such as increasing carbonation temperature regime, employing supercritical CO2, presence of surfactants, presence of salts, including deliquescent salts, and utilizing ultrafine particle sizes.

[0019] For reactive, finely ground or nanosized wollastonite exposed to a CO2and H2O vapor atmosphere at 40 °C to 90 °C, full carbonation can be achieved within 10 minutes to 30 minutes under pressures ranging from 25 bar to 125 bar. In contrast, the reaction proceeds much more slowly, requiring several hours to days, when conducted without elevated temperature, pressure, or steam. However, such accelerating conditionsare often impractical for large-scale industrial applications due to their energy intensity and equipment constraints.

[0020] What is needed is a sustainable, high-performance SCM that is not dependent on legacy waste streams; is compatible with current concrete infrastructure; and that may be produced through environmentally friendly, economically viable processes.

[0021] Therefore, there exists a continuing need for a scalable, energy-efficient process for synthesizing carbonated calcium silicate-based materials in a rapid, singlepass configuration. The present invention fulfills this need by providing an integrated, continuous process that enables the (1) low-temperature synthesis of reactive calcium silicates followed by (2) rapid carbonation to produce high-performance, CC>2-sequestered SCMs suitable for use in concrete applications.

[0022] There is a need in the cement production field to create a new and useful system and method for reactors used in synthesis of cementitious materials. This invention provides such a new and useful system and method.BRIEF SUMMARY OF THE INVENTION

[0023] Embodiments of the present invention relate to a system for producing a silicate material, the system comprising: a first reactor comprising a first spray nozzle and a first airlock; the first reactor configured to receive a superheated steam; the first reactor configured to receive a first process gas; a second reactor comprising a second spray nozzle and a second airlock; the second reactor configured to receive a steam; and the second reactor configured to receive a second process gas. In another embodiment, the first reactor further is disposed at an angle. In another embodiment, the first reactor comprises a first end cap. In another embodiment, the first reactor is a hydrothermal vapor recrystallization process reactor. In another embodiment, the system further comprises an inlet for introducing and disposing liquid water within said first reactor. In another embodiment, the first process gas comprises carbon dioxide. In another embodiment, the second reactor comprises a screw auger. In another embodiment, the second reactor comprises a second end cap. In another embodiment, the system further comprising an inlet for introducing and disposing liquid water within said second reactor.

[0024] Embodiments of the present invention also relate to a method for producing a silicate material, the method comprising: heating a feedstock; disposing the feedstock in a reactor; applying steam to the feedstock to yield a calcium silicate material; cooling the calcium silicate material; applying moisture to the calcium silicate material; and carbonating the calcium silicate material to yield a carbonated silicate material. In another embodiment, the method further comprises milling a raw material to form the feedstock. In another embodiment, the method further comprises conveying the feedstock through the reactor. In another embodiment, the method further comprises flowing a countercurrent stream of process gas through the reactor relative to the conveyed feedstock. In another embodiment, the method further comprises flowing a co-current stream of process gas through the reactor relative to the conveyed feedstock. In another embodiment, the feedstock comprises a of calcium and silicon bearing material.

[0025] Embodiments of the present invention also relate to calcium silicate material composition comprising: synthetic calcium silicate. In another embodiment, the synthetic calcium silicate comprises beta-dicalcium silicate. In another embodiment, the synthetic calcium silicate comprises alpha prime-dicalcium silicate. In another embodiment, the synthetic calcium silicate comprises gamma dicalcium silicate. In another embodiment, the synthetic calcium silicate comprises a pozzolanic amorphous phase.

[0026] Further scope of applicability of the present invention will be set forth in part in the detailed description to follow, taken in conjunction with the accompanying drawings, and in part will become apparent to those skilled in the art upon examination of the following, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0027] The accompanying drawings, which are incorporated into and form a part of the specification, illustrate one or more embodiments of the present invention and, together with the description, serve to explain the principles of the invention. The drawings are onlyfor the purpose of illustrating one or more embodiments of the invention and are not to be construed as limiting the invention. In the drawings:

[0028] Fig. 1 is flow diagram showing a single-stage system, according to an embodiment of the present invention;

[0029] Fig. 2 is a diagram showing a dual-stage system, according to an embodiment of the present invention;

[0030] Fig. 3 is a series of images showing synthesized powder, according to an embodiment of the present invention;

[0031] Fig. 4 is a series of images showing carbonated material, according to an embodiment of the present invention;

[0032] Fig. 5 is a graph showing a comparison of parawollastonite phase formation using the present invention versus a conventional solid-state reaction method, according to an embodiment of the present invention;

[0033] Fig. 6 is a series of images showing formed parawollastonite powder, according to an embodiment of the present invention;

[0034] Fig. 7 is a graph showing an X-ray diffraction (“XRD”) spectra of parawollastonite after three hours of reaction time, according to an embodiment of the present invention;

[0035] Fig. 8 is a graph showing an XRD spectra of parawollastonite prepared by the conventional solid-state reaction after four hours, according to an embodiment of the present invention;

[0036] Fig. 9 is a graph showing XRD spectra of parawollastonite prepared by the conventional solid-state reaction after 16 hours, according to an embodiment of the present invention;

[0037] Fig. 10 is a graph showing an XRD spectra of carbonated parawollastonite, according to an embodiment of the present invention;

[0038] Fig. 11 is a table showing mortar performance with carbonated wollastonite, according to an embodiment of the present invention;

[0039] Fig. 12 is a diagram showing a system comprising a mixer or mill, according to an embodiment of the present invention;

[0040] Fig. 13 is a diagram showing an expanded system comprising a mixer or mill, according to an embodiment of the present invention;

[0041] Fig. 14 is a diagram showing a system comprising a ball or media mill, according to an embodiment of the present invention;

[0042] Fig. 15 is a diagram showing an expanded system comprising a ball or media mill, according to an embodiment of the present invention;

[0043] Fig. 16 is a diagram showing a system comprising a vibro-energy mill, according to an embodiment of the present invention;

[0044] Fig. 17 is a diagram showing an expanded system comprising a vibro-energy mill, according to an embodiment of the present invention;

[0045] Fig. 18A is a diagram showing a system comprising a horizontal screw reactor variation, according to an embodiment of the present invention;

[0046] Fig. 18B is a flow chart showing a method variation used with a system comprising a horizontal screw reactor variation, according to an embodiment of the present invention;

[0047] Fig. 19A is a diagram showing a system comprising a tandem horizonal screw reactor, according to an embodiment of the present invention;

[0048] Fig. 19B is a flow chart showing a method variation used with a system comprising a tandem horizontal screw reactor, according to an embodiment of the present invention;

[0049] Fig. 20A is a diagram showing a system comprising an inclined rotary kiln variation, according to an embodiment of the present invention;

[0050] Fig. 20B is a flow chart showing a method variation used with a system comprising an inclined rotary kiln variation, according to an embodiment of the present invention;

[0051] Fig. 21A is a diagram showing a system comprising a vertical gravity reactor, according to an embodiment of the present invention;

[0052] Fig. 21 B is a flow chart showing a method variation used with a system comprising a vertical gravity reactor, according to an embodiment of the present invention;

[0053] Fig. 22A is a diagram showing a system comprising a horizontal autoclave reactor, according to an embodiment of the present invention;

[0054] Fig. 22B is a flow chart showing a method variation used with a system comprising a horizontal autoclave reactor, according to an embodiment of the present invention;

[0055] Fig. 23A is a diagram showing a system comprising a vertical reactor with a screw agitator, according to an embodiment of the present invention;

[0056] Fig. 23B is a flow chart showing a method variation used with a system comprising a vertical reactor with a screw agitator, according to an embodiment of the present invention;

[0057] Fig 24A is a diagram showing a system comprising a tandem rotary kiln configuration, according to an embodiment of the present invention;

[0058] Fig. 24B is a flow chart showing a method variation used with a system comprising a tandem rotary kiln configuration, according to an embodiment of the present invention;

[0059] Fig. 25A is a diagram showing a system comprising a rotary retort autoclave reactor, according to an embodiment of the present invention;

[0060] Fig. 25B is a flow chart showing a method variation used with a system comprising a rotary retort autoclave reactor, according to an embodiment of the present invention.DETAILED DESCRIPTION OF THE INVENTION

[0061] Embodiments of the present invention relate to a system for producing a silicate material, the system comprising: a mill in communication with a heat exchanger; a condenser in communication with a steam generator; a reactor comprising a fluid sprayer; a gas stream; and a reactor. The reactor may comprise a single chamber, wherein the single chamber comprises a plurality of zones. The reactor may comprise a plurality of chambers. The zones may comprise a synthesis, cooling, and carbonation zone. The plurality of chambers may comprise a synthesis, cooling, and carbonation chamber. A separator may be disposed between each of the plurality of chambers. The reactor may be configured to receive a superheated steam, process gas, steam, or a combination thereof.

[0062] Embodiments of the present invention relate to a method for producing a silicate material, the method comprising: milling a raw material to form feedstock; heating the feedstock; disposing the feedstock into a reactor; applying steam to the feedstock to yield a calcium silicate material; cooling and applying moisture to the calcium silicate material; and carbonating the calcium silicate material to yield a silicate material. Thermal treatment may be applied to feedstock disposed within the reactor. The silicate material may be an amorphous and / or crystalline silicate material. The method may further comprise conveying the feedstock through the reactor. The method may further comprise flowing a countercurrent and / or co-current stream of water and / or carbon dioxide through the reactor relative to the conveyed feedstock. The method may comprise passing the feedstock through a synthesis zone or chamber to form a calcium silicate material. The method may further comprise passing the calcium silicate material through a cooling zone or chamber to yield a cooled silicate or calcium silicate material. The method may comprise use of a cooling chamber to cool a silicate and / or calcium silicate material. The silicate and / or calcium silicate material may be cooled by disposing fluid onto the silicate and / or calcium silicate material to yield a cooled and moist silicate and / or calcium silicate material. Alternatively, the silicate and / or calcium silicate material may be cooled by passing the hot silicate powder through a solid-gas heat exchanger to yield a dry silicateand / or calcium silicate material. The method may further comprise passing the cooled moist calcium silicate or dry calcium silicate material through a carbonation zone or chamber to yield the silicate material.

[0063] The system and / or method may eliminate inter-reactor material handling (where the system and method are an integrated system), enhance thermal integration, and reduce process complexity. The system and / or method may offer a scalable solution for decarbonized cementitious material production.

[0064] The system and / or method may overcome long-standing limitations in the scalable production and carbonation of reactive calcium silicates. Unlike conventional solid-state methods that require high temperatures that yield coarse materials, the system and / or method may enable the synthesis of nanosized, high-surface-area calcium silicates including parawollastonite at moderate temperatures (e.g., about 500 °C to about 900 °C), significantly lowering energy requirements. The use of a flowing CO2and steam atmosphere may facilitate enhanced diffusion and reaction kinetics. Optimized carbonation parameters including, but not limited to, gas flow, temperature, time or a combination thereof may eliminate or mitigate the need for the multiple grinding and carbonation steps.

[0065] The direct integration of synthesis and carbonation may allow for single-pass, rapid CO2mineralization without reliance on pure CO2streams or repetitive milling and reaction cycles. Single pass carbonation may be performed in single stage or dual stage systems and methods. The system and / or method may be a streamlined, continuous process that is advantageous over traditional wet chemical or batch hydrothermal methods, which are limited by cost, throughput, and scalability. The system and / or method may establish a practical, industrially scalable route for producing carbon-sequestering materials that form supplementary cementitious materials after carbonation by combining flowing water vapor-phase synthesis, surface area optimization, and efficient carbonation into a unified platform. The system and / or method may have implications for low-carbon construction and CO2removal technologies.

[0066] Embodiments of the present invention relate to a system and / or method for continuous carbonation for reactive mineral powders, such as synthetic calcium silicate (CaxSiyOZ). The system and / or method may enable the production of high-quality SCMs viaCO2mineralization. The system and / or method may allow for continuous powder flow; moisture control; operation under moderate temperature conditions with steam and CO2injection; or a combination thereof. The system and / or method may support a plurality of material conveyance mechanisms including, but not limited to screw augers, vibratory beds, tray-based feeders or a combination thereof. The system and / or method may provide design flexibility and / or scalability.

[0067] Embodiments of the present invention relate to a system and / or method for cementitious materials production and / or carbon dioxide (CO2) capture, sequestration, and utilization. The method may be an integrated continuous process that sequentially performs low-temperature synthesis, intermediate cooling, and low-temperature carbonation of calcium silicate powders. The system may comprise a single reactor and the method may occur in a single reactor. The reactor may comprise a rotary kiln. The system and / or method may enable efficient CO2mineralization and production of supplementary cementitious material (“SCM”). The reactor may be configured to receive a superheated steam, process gas, steam, ora combination thereof.

[0068] Embodiments of the present invention relate to a system and / or method for supplementary cementitious material production and / or carbon capture. The method may comprise two sequenced continuous processes: low-temperature synthesis of dry, multication inorganic oxide powders in a reaction atmosphere comprising gaseous carbon dioxide (CO2) and gaseous water vapor (H2O) at partial pressures; and (2) to a continuous, single-pass stage for carbonating calcium silicate powders to produce stable, CO2-sequestered supplementary cementitious material (“SCM”). The SCM may be used in concrete and related applications.

[0069] Embodiments of the present invention relate to a system and / or method for synthetic calcium silicate (e.g., wollastonite or parawollastonite) synthesis and carbonation. The synthetic calcium silicate may be of the form CaxSiyOzwhere X, Y, and Z may be integers. The synthetic calcium silicate include, but it not limited to, wollastonite, parawollastonite, pseudo-wollastonite, beta-dicalcium silicate, alpha prime-dicalcium silicate, gamma dicalcium silicate, or a combination thereof. Parawollastonite is a calcium silicate material comprising a CaO: SiO2molar ratio of approximately one. The method may comprise a continuous, low-temperature process for producing nanosized, high-surface-area parawollastonite and related phases from ground raw materials. The method may beperformed at a temperature of between about 500 °C to about 900 °C. The method may be performed under a flowing atmosphere of CO2and water vapor at pressures below those associated with deep crustal conditions. The method may be integrated with a single-step carbonation stage that converts the synthesized material into a silicate material ( / .e., a carbon-sequestered supplementary cementitious material (“SCM”)).

[0070] Embodiments of the present invention relate to a system and / or method for gas-solid reactions in reactive mineral powders. The system and / or method may be a continuous process for the carbonation and / or mineralization of carbonatable materials. Carbonatable materials may undergo carbonation and / or mineralization using steam and carbon dioxide gas streams under controlled temperature and moisture conditions. The system may be modular and the system and / or method may comprise material handling; gas injection; fluid spray; a mineralization vessel (J.e., a reactor); control system / sensors subsystems; or a combination thereof. The system and / or method may enable continuous material flow; control of carbonation kinetics; CO2uptake; or a combination thereof. The system and / or method may comprise plurality of conveyance technologies including, but not limited to, a screw mixer, an auger mixer, a media mill, a vibro-energy mill; or a combination thereof. The system and / or method may be configured to receive feedstock types and / or accommodate different process requirements, production scales, or a combination thereof.

[0071] The terms “supplementary cementitious material” or “SCM” as used herein mean a material and / or compound added to concrete to improve its performance and reduce its environmental impact. The SCM comprises a pozzolan.

[0072] The term “engineered” as used herein means produced under controlled reaction parameters including, but not limited to, temperature, pressure, CO2and water vapor concentration, fluid flow rate, degree of powder agitation, or combination thereof.

[0073] The term “carbonation reactivity” as used herein refers to the ability of calcium silicate-based powders to rapidly and efficiently react with CO2in the presence of moisture (e.g., water vapor or liquid water) to form stable carbonate phases including, e.g., calcium carbonate (CaCO3), and a silica-rich phase, e.g., amorphous SiO2.

[0074] The term “highly reactive carbonatable material” as used herein means a carbonatable material that otters low value of carbonation activation energy (e.g., <10kJ / mol) leading to CO2 uptake (e.g., 25 wt% to 35 wt%) in a short residence time (e.g., <30 minutes) under a single-pass processing condition.

[0075] The term “ASTM C311” as used herein refers to the standard test methods for sampling and testing fly ash or natural pozzolans for use in Portland-cement concrete as published by the American Society for Testing and Materials (“ASTM”).

[0076] The term “ASTM C109” as used herein refers to the standard test method for compressive strength of hydraulic cement mortars (using 2-in. or [50-mm] cube specimens) as published by the American Society for Testing and Materials (“ASTM”).

[0077] The term “ASTM C1897-20 - Method B” as used herein refers to the standard test methods for measuring the reactivity of supplementary cementitious materials by isothermal calorimetry and bound water measurements) as published by the American Society for Testing and Materials (“ASTM”).

[0078] The term “vapor-phase synthesis” as used herein means the making of chemical product in a vapor environment.

[0079] As used herein, “method” may refer to the method for cementitious materials production and / or carbon dioxide (CO2) capture, sequestration, and use; the method for supplementary cementitious material production and / or carbon capture; and / or the method for parawollastonite synthesis and carbonation.

[0080] As used herein, “system” may refer to the system for cementitious materials production and / or carbon dioxide (CO2) capture, sequestration, and use; the system for supplementary cementitious material production and / or carbon capture; and / or the system for parawollastonite synthesis and carbonation.

[0081] Turning now to the figures, Fig. 1 shows system 2. System 2 comprises raw material silo 4, mill 6, feedstock hopper 10, heat exchanger 12, condenser 14, vessel 16, steam generator 18, and reactor 8. Raw material is collected in raw material silo 4. Raw material is conveyed to mill 6 where the raw material is milled to form feedstock.Feedstock is conveyed to feedstock hopper 10 and then conveyed to heat exchanger 12.Heat exchanger 12 receives hot steam and carbon dioxide stream 38 to produce heated feedstock stream 40. Heated feedstock stream 40 enters reactor 8. Reactor 8 comprises synthesis zone 42, cooling zone 44, and carbonation zone 46. Heated feedstock enters synthesis zone 42 ( / .e., the hydrothermal vapor recrystallization process (“HVRP”) reactor of Figs. 18A-25B) where a reaction occurs to produce calcium-silicates, non-silicates, and amorphous material. The temperature of the synthesis zone increases from about 25 °C to about 750 °C to 800 °C. The reaction occurs in less than three hours. The product produced by synthesis zone 42 is in the form of dry powder and / or soft agglomerates.

[0082] The reacted product (comprising calcium silicate) from synthesis zone 42 enters cooling zone 44 at 750 °C to 800 °C, where no heating elements or external heat sources are present to form a hot product powder ( / .e., moist product). Water is sprayed onto the hot product powder from spray nozzle 34 to facilitate cooling. The process generates saturated steam at 100 °C, with the quantity of water controlled to extract heat from the hot product powder. The generated saturated steam 36 originating from cooling zone 44 enters synthesis zone 42. The feedstock reacts in synthesis zone 42 when also exposed to steam 32 originating from the steam generator 18. The moisture content of the hot product powder in cooling zone 44 is 0.5 wt% to 40 wt%.

[0083] Moist product enters carbonation zone 46. The moist product reacts with humid carbon dioxide introduced into reactor 8, with CO2and steam stream 24 flowing counter-current to the solid material stream. An exothermic reaction occurs between the carbonatable phase in the moist product and CO2, resulting in the formation of CaCO3and amorphous SiO2. The CO2may be in any form including, but not limited to, gaseous, ionic, aqueous, bi-carbonate ion, carbonate ion, carbonic acid, adsorbed, chemisorbed, physisorbed, or a combination thereof. The reaction zone is of sufficient length to enable near-complete conversion, achieving a CO2uptake of 25% to 35%. The exothermic nature of the reaction helps maintain the zone temperature within the desired range of 40 °C to 90 °C. Carbonation zone 46 yields carbonated powder. The carbonated powder exits reactor 8 for post-processing, which may include drying and milling. If reaction zone 46 is of sufficient length and / or equipped with heat sources, drying may occur within reactor 8 prior to discharge. The dried carbonated powder product is subsequently milled to achieve a desired particle size distribution.

[0084] A gas mixture comprising CO2and sulfur compounds (e.g., H2S and SO2) enters sulfur scrubber 20. Humid CO222 from sulfur scrubber 20 is conveyed to reactor 8 as CO2and steam stream 24. CO2and steam stream 24 enters carbonation zone 28, and steam stream 26 exits carbonation zone 28. Gas stream from heat exchanger 12 enters condenser 14 where it is condensed to water and conveyed into water vessel 16. Water stream 30 from water vessel 16 is conveyed to spray nozzle 34 to apply moisture to the reacted product.

[0085] Fig. 2 shows system 48 comprising reactor 50, conveyance system 52, and reactor 54. Reactor 50 comprises angle 82. Feed stock enters hopper 56 and passes through rotary airlock 58 before proceeding through infeed 60 and into reactor 50. Reactor 50 ( / .e., the hydrothermal vapor recrystallization process (“HVRP”) reactor of Figs. 18A-25B) comprises kiln end caps 62 and 78, shell wall 72, heat jack 70, and outer shell 68. Raw material 64 is propelled horizontally inside reactor 50 by rotary motion. Heat is provided to raw material 64 via heat transfer through the wall of reactor 50. Superheated steam and process gas 74 is passed into reactor 50 through spray nozzle 76 to catalyze the reaction of raw material 64 into reacted material 84. Exhaust gases 66 are flowed out of system 48 with the introduction of new gas. Reacted material 84 passes through outfeed 80 and rotary airlock 58’ and into hopper 56’. Reacted material 84 is moved from hopper 56” to reactor 54 ( / .e., the mineralizer) via rotary valve 88 and material transfer screw 86. Reacted material 84 passes through rotary airlock 58’ and infeed 60’ as uncarbonated material 96. Uncarbonated material 96 is propelled horizontally inside reactor 54 by screw auger 114 comprising shaft 112 and motor / actuator 92. Reactor 54 comprises spray nozzles 94 and 98, shell wall 100, heat jacket 105 and outer shell 110. Heat is provided or removed to or from uncarbonated material 96 via heat transfer through the wall of reactor 54. Steam and process gas 116 is introduced to catalyze the reaction of uncarbonated material 96 into product 122. Exhaust gases 90 are flushed out of system 48 with the introduction of new gas. Product 122 passes through outfeed 120, rotary airlock 58’” and hopper 56’” before exiting system 48.

[0086] Fig. 3 shows scanning electron micrographs of synthesized powder at 1,000 times and 40,000 times magnification.

[0087] Fig. 4 shows scanning electron micrographs of carbonated material at 10,000 times and 20,000 times magnification.

[0088] Fig. 5 shows a comparison of parawollastonite phase formation using the present invention versus a conventional solid-state reaction method. In both cases, the feedstock is prepared by mixing ground limestone (CaCO3) with ground quartz (SiO2). The disclosed process is performed at 800 °C, while the solid-state reaction is performed at 1000 °C. The disclosed method achieved near-complete conversion to parawollastonite within two hours, whereas the traditional solid-state process yields only about 35% parawollastonite after 16 hours of reaction, despite operating at a temperature 200 °C higher.

[0089] Fig. 6 shows a scanning electron micrograph of parawollastonite powder formed by the method and system of the present invention.

[0090] Fig. 7 shows an XRD spectra of Parawollastonite (wollastonite-2M) prepared by the disclosed invention. The spectra conditions are 850 °C, three hours of reaction time under CO2and water vapor flowing stream. Corundum is the calibration standard.

[0091] Fig. 8 shows an XRD spectra parawollastonite (wollastonite-2M) prepared by the conventional solid-state reaction at 1000 °C after four hours reaction in air.

[0092] Fig. 9 shows an XRD spectra parawollastonite (wollastonite-2M) prepared by the conventional solid-state reaction at 1000 °C after 16 hours reaction in air.

[0093] Fig. 10 shows an XRD spectra of carbonated parawollastonite (wollastonite-2M). The spectra conditions are 800 °C, three-hour reaction time, under CO2and water vapor flowing stream. Carbonation is performed at 60 °C.

[0094] Fig. 11 shows mortar performance with carbonated wollastonite. Portland limestone cement (“PLC") is partially replaced with 30% carbonated wollastonite by mass.

[0095] Fig. 12 shows a system 124 comprising a mixer or mill. The reactor comprises shell wall 138, heat or cool jacket 140, spray nozzles 136 and 136’ and outer shell 142.Carbonatable material 148 is moved from hopper 126 into reactor through rotary airlock 128 and infeed 130. Carbonatable material 148 is propelled horizontally inside reactor byscrew auger comprising screw 146, shaft 144, and motor 132. Steam and process gas (e.g., CO2) 155 are introduced into the reactor to catalyze the reaction. Reacted material 160 drops into product hopper 126’, through outfeed 150, and rotary airlock 128’. Exhaust gases are flushed out of the system via exhaust vent 134.

[0096] Fig. 13 shows an expanded system 162 comprising a mixer or mill. First reactor comprises shell wall 178, heat or cool jacket 180, spray nozzles 176 and outer shell 182. Carbonatable material 172 is moved from hopper 164 into reactor through rotary airlock 166 and infeed 168. Carbonatable material 172 is propelled horizontally inside reactor by screw auger comprising screw 186, shaft 184, and motor 170. Steam and process gas (e.g., CO2) 188 are introduced into the first reactor to catalyze the reaction. Exhaust gases are flushed out of the system via exhaust vent 174. First reacted material 192 drops into second reactor through outfeed 190, rotary airlock 166’, and infeed 168’. Second reactor comprises shell wall 178’, heat or cool jacket 180’, spray nozzles 176’ and outer shell 182’. First reacted material 192 is propelled horizontally inside reactor by screw auger comprising screw 186’, shaft 184’, and motor 170’. Steam and process gas (e.g., CO2) 188’ are introduced into the first reactor to catalyze the reaction. Exhaust gases are flushed out of the system via exhaust vent 174’. Second reacted material 194 drops into product hopper 164’, through outfeed 190’, and rotary airlock 166”.

[0097] Fig. 14 shows a system 196 comprising a ball or media mill. The reactor comprises shell wall 202, heat or cool jacket 204, spray nozzles 200 and outer shell 206. Reactor is disposed at angle 220. Carbonatable material 218 is moved from hopper 208 into reactor through rotary airlock 210 and infeed 212 Grinding media 222 reduces the size of carbonatable material particles. Steam and process gas (e.g., CO2) 198 are introduced into the reactor to catalyze the reaction. Reacted material 228 drops into product hopper 208’, through outfeed 226, and rotary airlock 210’. Exhaust gases are flushed out of the system via exhaust vent 216.

[0098] Fig. 15 shows an expanded system 230 comprising a ball or media mill. First reactor comprises shell wall 260’, heat or cool jacket 258’, end cap 238, spray nozzles 252’ and outer shell 256’. Reactor is disposed at angle 246. Carbonatable material 240 is moved from hopper 232 into reactor through rotary airlock 234 and infeed 238. Grinding media 242 and 242’ reduces the size of carbonatable material particles. Steam and process gas (e.g., CO2)250’ are introduced into the first reactor to catalyze the reaction.Exhaust gases are flushed out of the system via exhaust vent 254’. First reactor is separated from second reactor by separator 244. Second reactor comprises shell wall 260, heat or cool jacket 258, end cap 262, spray nozzles 252 and outer shell 256. Steam and process gas (e.g., CO2) 250’ are introduced into the second reactor to catalyze the reaction. Exhaust gases are flushed out of the system via exhaust vent 254. Reacted material 266 drops into product hopper 232’, through outfeed 264, and rotary airlock 234’.

[0099] Fig. 16 shows a system 268 comprising a vibro-energy mill. The reactor comprises shell wall 284, heat jacket 282, spray nozzles 278, end caps 296 and 286, and outer shell 280. Reactor is disposed at angle 290. Carbonatable material 288 is moved from hopper 270 into reactor through rotary airlock 272 and infeed 274. Carbonatable material is propelled horizontally inside the reactor by rotary motion of the reactor.Grinding media 292 reduces the size of carbonatable material particles. Steam and process gas (e.g., CO2) 294 are introduced into the reactor to catalyze the reaction.Reacted material 300 drops into product hopper 270’, through outfeed 298, and rotary airlock 272’. Exhaust gases are flushed out of the system via exhaust vent 276.

[0100] Fig. 17 shows an expanded system 302 comprising a vibro-energy mill. First reactor comprises shell wall 320’, heat jacket 318’, end cap 310, spray nozzles 312’, and outer shell 316’. Reactor is disposed at angle 330. Carbonatable material 324 is moved from hopper 304 into reactor through rotary airlock 306 and infeed 308. Grinding media 326 and 332 reduces the size of Carbonatable material particles. Steam and process gas (e.g., CO2)322’ are introduced into the first reactor to catalyze the reaction. Exhaust gases are flushed out of the system via exhaust vent 314’. First reactor is separated from second reactor by separator 328. Second reactor comprises shell wall 320, heat or cool jacket 318, end cap 334, spray nozzles 312, and outer shell 316. Steam and process gas (e.g., CO2) 322 are introduced into the second reactor to catalyze the reaction. Exhaust gases are flushed out of the system via exhaust vent 314. Reacted material 338 drops into product hopper 304’, through outfeed 336, and rotary airlock 306’. Carbonatable material is propelled horizontally inside the reactor by rotary motion of the reactor.

[0101] Fig. 18A shows a system 340 comprising a horizontal screw reactor variation. The reactor comprises shell wall 354, heat jacket 356, and outer shell 358. Feedstock 352 is moved from hopper 342 into reactor through rotary airlock 344 and infeed346. Feedstock 352 is propelled horizontally inside reactor by screw auger comprising screw 362, shaft 360, and motor 350. Superheated steam and process gasses 348 are introduced into the reactor to catalyze the reaction. Reacted material 368 drops into product hopper 342’, through outfeed 366, and rotary airlock 344'. Exhaust gases are flushed out of the system via exhaust vent 364. A horizontal screw reactor variation of the system may use a system configuration and method of operation for heating and material conveyance employing an external heating system and / or a heated screw.

[0102] Fig. 18B shows a method variation used with a system comprising a horizontal screw reactor variation as shown in Fig. 18A. The method may comprise: moving feedstock from a hopper or material source to a reactor, propelling the feedstock inside the reactor vessel by a screw auger, heating the feedstock, introducing superheated gaseous material into the reactor, exhausting the gaseous material, and depositing reacted material from the reaction vessel.

[0103] Fig. 19A shows a system 370 comprising a tandem horizonal screw reactor. First reactor comprises shell wall 384, heat jacket 386, and outer shell 388. Feedstock 382 is propelled horizontally inside reactor by screw auger comprising screw 392, shaft 390, and motor 380. Exhaust gases are flushed out of the system via exhaust vents 568 and 568’. Superheated steam and process gasses 378 are introduced into the reactor to catalyze the reaction. Reacted material 382’ drops into second reactor, which comprises shell wall 384’, heat jacket 386’, and outer shell 388’, through outfeed 394, rotary airlock 374’, and infeed 376’. Reacted material 382’ is propelled horizontally inside reactor by screw auger comprising screw 392’, shaft 390’, and motor 380’. Superheated steam and process gasses 378’ are introduced into the reactor to catalyze the reaction. Reacted material 396 drops into product hopper 372’, through outfeed 394’, and rotary airlock 374”.

[0104] A tandem horizontal screw reactor variation may be an extension to the single horizontal screw reactor variation. The tandem approach may enable additional capabilities. Adding two or more tandem units of reactors may allow more fine control over the process while also optimizing the capital cost of procuring a much longer or larger single unit. In Fig. 23A, two horizontal screw reactor units are shown but the different reactor units may comprise any combination of reactor units described herein, and they may the same or different types of reactor units. Each tandem screw reactor unit may be maintained at its own specific temperature and / or atmospheric conditions. Each unit mayalso have a different diameter, rotational speed, and / or screw design. This may enable fine tune control of reaction kinetics and product formation at each step of the process.

[0105] Fig. 19B shows a method variation used with a system comprising a tandem horizontal screw reactor. The method variation, which may use tandem reactors as shown in Fig. 23A or other compatible combination of reactor units, may comprise: moving feedstock from a hopper or material source to a reactor, propelling the feedstock inside the reactor vessel by a screw auger, heating the feedstock, introducing superheated gaseous material into the reactor, exhausting the gaseous material, and depositing reacted material from the reaction vessel into a subsequent stage reactor vessel, and repeating processing of the reacted material within the subsequent stage reactor vessel until depositing fully-reacted material into a product hopper. Material may be dumped or otherwise deposited using a rotary valve or other material handling system.

[0106] Fig. 20A shows a system 398 comprising an inclined rotary kiln variation. The reactor comprises shell wall 412, heat jacket 414, kiln end cap 402, and outer shell 416.The reactor is disposed at angle 424. Feedstock 422 is moved from hopper 404’ into reactor through rotary airlock 406’ and infeed 418. Superheated steam and process gasses 400 are introduced into the reactor to catalyze the reaction. Reacted material 410 drops into product hopper 404, through outfeed 408, and rotary airlock 406. Exhaust gases are flushed out of the system via exhaust vent 426. Feedstock is propelled horizontally by the rotary motion of the rotary kiln.

[0107] An inclined rotary kiln variation of the reaction vessel may be configured for lower temperatures of the targeted reaction. The use of lower temperatures may enable the use of fuel fired kilns or more efficient indirectly heated electrical kilns. The use of electrically powered kilns may have the potential benefit of opening a door to fully carbon neutral operation as the entire process can be powered with renewable energy. The lower temperatures may allow the kiln to be constructed from non-exotic materials; reduce construction cost; and / or reduce kiln maintenance / overhaul intervals that may be required for existing high temperature direct flame heated kilns used in the cement industry. In addition, indirectly heated kilns have improved control over their internal atmosphere. Without combustion gases needing to be exhausted constantly to maintain a flame, a specific atmosphere composition and mass flow rate may be maintained. This fine tune control over the atmosphere inside the reaction vessel may allow for greater control overproduct uniformity and quality. Non-exhaustively, other methods of heating including waste-heat, geothermal heat, solar thermal heat, hydrogen combustion and others may additionally or alternatively be used.

[0108] Fig. 20B shows a method variation used with a system comprising an inclined rotary kiln variation. Material may be fed into and out of the system using existing industrial methods such as dump valves, lock hoppers, or rotary air locks. The atmosphere is then controlled with mass flow controllers and relief valves. The residence time is controlled via a combination of the kiln incline and rotational speed. After a specific residence time has been achieved, the material may be removed using the same equipment as for infeed.

[0109] By running the hydrothermal vapor recrystallization process (“HVRP”) or other steam-based reaction process at lower temperatures, energy efficiency and carbon neutrality may be enabled within such a reactor. Lower temperature kilns need to account for the gas atmosphere produced by the reaction. Melt-phase homogenization may increase reaction kinetics (i.e., decreases the needed residence time) and therefore creates resistance to negative effects (kinetic or thermodynamic) that may be posed by the reaction atmosphere. For example, the buildup of CO2in the atmosphere from limestone decomposition and fuel combustion negatively affects the product purity and reaction kinetics. A partial high-temperature melt offsets these negative effects.

[0110] In some variations, lower temperature HVRP may not get hot enough to melt the materials and thus may help facilitate controlling the atmosphere gas input and output to maintain a specific gas pressure gradient to maintain kinetics.

[0111] Fig. 21A shows a system 428 comprising a vertical gravity reactor. The reactor comprises shell wall 438, heat jacket 440, center shaft 444, and outer shell 442. Feedstock 436 is moved from hopper 430 into reactor through rotary airlock 432 and infeed 434. Feedstock 436 is propelled vertically inside the reactor by gravity. Superheated steam and process gasses 446 are introduced into the reactor to catalyze the reaction. Reacted material drops into product hopper 454, through outfeed 450, and rotary airlock 452. Exhaust gases are flushed out of the system via exhaust vent 448.

[0112] The reaction vessel may be configured as a vertical gravity reactor that utilizes gravity (at least in part) to facilitate material movement through the reaction vessel.The vertical gravity reactor shown in Fig. 25A may be configured as a fluidized or static bed reactor, possibly with additional specialized configuration.

[0113] Fig. 21 B shows a method variation used with a system comprising a vertical gravity reactor. In the gravity reactor no fluidization may be used. A minimal amount of steam or other gases may be used to sufficiently catalyze the reaction. This process is shown in Fig. 25B. The lower gas usage maintains the energetics at low value needed to operate the kiln cost effectively while allowing the material to slowly make its way down the vessel. Material delivered to the reactor is synchronized with material being removed from the bottom of the reactor. The feed rate out of the vessel controls the overall residence time within the chamber.

[0114] Fig. 22A shows a system 456 comprising a horizontal autoclave reactor.Feedstock 466 is placed on tray table 464 and rolled into reactor vessel comprising shell wall 470, heat jacket 472, infeed 460, outfeed 462, wheels 468, and outer shell 474. Door 458 is closed after feedstock 466 enters the reactor. Superheated steam and process gasses 476 are introduced into the reactor to catalyze the reaction. Exhaust gases are flushed out of the system via exhaust vent 478.

[0115] Traditional horizontal autoclave systems are not compatible with traditional synthesis of cement or cementitious materials due to the high temperatures of traditional material synthesis processes. However, with the moderate temperatures experienced by the HVRP or other steam-based processes, a horizontal autoclave reactor may be retrofitted to produce cementitious materials at sufficient scale. In an autoclave reactor system, the reactor vessel may include one or more doors / openings that can be opened and closed.

[0116] Fig. 22B shows a method variation used with a system comprising a horizontal autoclave reactor. The process may initiate with loading prepared feedstock material into trays or other holders and placed on to a special platform that can be rolled into the horizontal autoclave. An autoclave door is closed, and the entire system may be heated (electrically heated or otherwise) to a targeted reaction temperature. A control system may monitor the internal atmosphere and inject superheated steam or other gases while also exhausting gases created by the reaction. Once the intended residence time is achieved,the atmosphere is purged, the chamber is sufficiently cooled, and the door opens. The material is removed from the trays and the process can begin again.

[0117] This reactor system may enable parallel operation of multiple horizontal autoclaves concurrently. This may reduce risks associated with shutdown or maintenance as only a single unit out of many may be down at any given time. The overall uptime of the system may be maintained. Parallel operation also allows for simultaneous production of multiple recipes without having to shut down and clean out existing rotary kilns.

[0118] Fig. 23A shows a system 480 comprising a vertical reactor with a screw agitator. The reactor comprises shell wall 494, heat jacket 496, gas diffusion plate 510, and outer shell 498. Feedstock 488 is moved from hopper 482 into reactor through rotary airlock 484 and infeed 486. Feedstock 488 is propelled vertically inside reactor by screw auger comprising screw 490, shaft 492, and motor 506. Superheated steam and process gasses 512 are introduced into the reactor to catalyze the reaction. Reacted material drops into product hopper 504, through outfeed 500, and rotary airlock 502. Exhaust gases are flushed out of the system via exhaust vent 508.

[0119] There may be various potential benefits of a vertical reaction vessel. For example, gravity will naturally help move the material downward. The larger column of material may also naturally speed up the kinetics of the reaction due to a larger weight of material compressing all the particles closer together. The system may comprise and use a gas distribution plate to inject steam or other gases into the processing vessel which may enable consistent and even gas flow across the entire powder bed.

[0120] A fluidized bed reactor to lower gas velocities may be used by the systems and methods herein comprising a vertical screw running down the middle of the system. This screw may allow for fine tune control over the agitation and mixed-ness within the system. The agitation may allow the material to move as if the system was being fluidized but without using extremely high flow velocities.

[0121] Fig. 23B shows a method variation used with a system comprising a vertical reactor with a screw agitator. In this method variation, material may be fed into the system via an atmosphere controlling valve such as a lock hopper or rotary airlock. Heat may be added with either or both the shell wall or the agitating screw itself. Indirect electrical heatmay be used for heating the shell wall and methods described herein in the screw reactor design may be used for the agitator itself. Once sufficient residence time is achieved the material can be fed out.

[0122] Material may be fed out of the system via an atmosphere controlling valve such as a lock hopper or rotary airlock. The rate of material fed by these valves controls the fill percentage and the residence time within the vessel.

[0123] A vertical reactor with screw agitator may have the ability to control the material propagation and particle contact by actively breaking up or agitating the material blend throughout the reaction. This agitation may help expose previously unexposed surfaces to the reaction atmosphere to maintain or enhance the reaction kinetics. In addition, the agitation may also help release trapped gases inside the material blend which allows for atmosphere composition characterization to control and maintain the process atmosphere for optimal kinetics.

[0124] Fig. 24A shows a system 514 comprising a tandem rotary kiln configuration. First reactor comprises shell wall 524’, heat jacket 526’, kiln end cap 532, and outer shell 528’. The reactor is disposed at angle 538. Feedstock 534 is moved from hopper 516’ into reactor through rotary airlock 518’ and infeed 530. Superheated steam and process gasses 520’ are introduced into the reactor to catalyze the reaction. Exhaust gases are flushed out of the system via exhaust vent 522’. First reactor is separated from second reactor by kiln separator 536. Reacted material is transferred from first reactor to second reactor. Second reactor comprises shell wall 524, heat jacket 526, kiln end cap 542, and outer shell 528. Superheated steam and process gasses 520 are introduced into the reactor to catalyze the reaction. Exhaust gases are flushed out of the system via exhaust vent 522’. Reacted material 544 drops into product hopper 516, through outfeed 540, and rotary airlock 518. Feedstock is propelled horizontally by rotary motion of the rotary kiln.

[0125] The system may make use of rotary kiln configured reaction vessels that are integrated and used in tandem. A system variation with a tandem rotary kiln configuration as shown in Figure 28A may be an extension or variation to a version using single rotary kiln configuration.

[0126] The HVRP and / or steam-based reaction process described herein uses much lower temperatures than traditional cement production process, and different reactions can occur at different temperatures and atmospheric conditions. In some scenarios, the use of multiple units used in tandem may have a potential benefit of being more efficient compared to a single large unit. Multiple smaller rotary kilns may enable sequential processing of the material and more efficiently produce reacted product without needing to heat a single large kiln to temperatures that are only needed for small period of time.

[0127] Fig. 24B shows a method variation used with a system comprising a tandem rotary kiln configuration. Material enters the kiln via rotary air lock or dump valve. This material falls into the first rotary kiln section. In the first rotary kiln section, the temperature and gas environment are especially suited for calcination as an example. The exhaust gas may be removed via an independent exhaust system that will not impact the rest of the process. The resultant intermediate product may now be mostly free of CO2and may move into the next section. A transition segment that connects the various rotary kilns may keep the atmosphere separated between the kilns and only allow the product to flow between the sections.

[0128] As the intermediate product enters the second section, the rotary speed, length, temperature and atmosphere are especially suited for the reaction portion of the process. The material moves through the vessel with a tightly controlled residence time and moves into the next transition section as a fully reacted product. This may be the end of the overall process, and the material could be removed via another rotary airlock or lock hopper.

[0129] If another processing step is desired, for example carbonation or mineralization, the material could move into a third rotary kiln section with its own reaction dependent rotary speed, temperature, and atmospheric conditions. The different processing steps may vary in the required temperature, atmosphere, and rotation speeds, and the individual sections may configured for specific temperature, atmosphere, and rotation parameters.

[0130] In the rotary kiln variation, the use of an HVRP or steam-based process may enable operation of the rotary kilns within a lowered temperature range that is not typical in traditional cement plant kilns. With lower temperature HVRP or a steam-based process the reactor does not get hot enough to melt the materials and thus controls the atmosphere gas input and output to maintain a specific gas pressure gradient to maintain kinetics.

[0131] Fig. 25A shows system 546 comprising a rotary retort autoclave reactor. The reactor comprises shell wall 554, heat jacket 556, rotation mechanisms 556 and 556’, infeed 550, outfeed 552, and outer shell 558. The reactor is disposed at angle 560.Feedstock 559 is disposed inside reactor, door 548 is closed, and rotation mechanisms 556 and 556’ rotate the reactor. Superheated steam and process gasses 564 are introduced into the reactor to catalyze the reaction. Exhaust gases are flushed out of the system via exhaust vent 566.

[0132] The rotary retort autoclave variation is a variation of the horizontal autoclave reactor variation described herein and shown in Fig. 25A. In this variation, the autoclave may be able to rotate. Depending on the application, this variation may have advantages and / or alternative features compared to the normal stationary autoclave. Rotary motion allows a raw material to tumble and mix, meaning every particle will come in contact with the heated wall. This will greatly decrease the time required for heating up of material to the required reaction conditions.

[0133] Fig. 25B shows a method variation used with a system comprising a rotary retort autoclave reactor. The process starts with prepared material loaded into the rotary retort autoclave. The autoclave door is closed, and the entire system is electrically heated to the correct reaction temperature. A control system may monitor the internal atmosphere and inject superheated steam or other gases while also exhausting gases created by the reaction. The control system will also control the rotary RPM of the system to maintain good mixing and agitation. Once the intended residence time is achieved, the rotation is stopped, the atmosphere is purged, the chamber is sufficiently cooled, and the door opens. The reactor is tilted, rotation is enabled, and the material is removed.

[0134] This reactor design variation may enable parallel operation of multiple rotary retort autoclaves concurrently. This may reduce risks associated with shutdown or maintenance as only a single unit out of many may be down at any given time. The overalluptime of the system would be maintained. Parallel operation also allows for simultaneous production of multiple recipes without having to shut down and clean out existing rotary kilns. Product switching is a complicated and laborious process in existing cement plants, which could be addressed by such a system variation. The reactor may be configured to receive a superheated steam, process gas, steam, or a combination thereof.

[0135] The method may comprise a continuous, integrated process for producing CO2-sequestered supplementary cementitious material (“SCM”) in a single reactor. The reactor may be configured to receive a superheated steam, process gas, steam, or a combination thereof. The reactor may comprise a rotary kiln. The method may combine three sequential stages within a single reactor. The first stage may comprise low-temperature synthesis (e.g., 600 °C to 800 °C) of carbonation-reactive calcium silicate powders in the presence of flowing CO2and H2O vapor. The second stage may comprise intermediate water spray cooling that reduces powder temperature to below 150 °C while establishing target moisture contents (e.g., 0.5 wt% to 40 wt% water). The third stage may comprise low-temperature carbonation (e.g., <150 °C) in the reactor using co-current flowing or counter-flowing CO2and steam. The low-temperature carbonation may achieve high CO2uptake (e.g., 25 wt% to 35 wt%) in a single pass without recirculation.

[0136] The system and / or method may receive a feedstock. The feedstock may comprise a calcareous and / or siliceous component including, but not limited to, a calcium and / or silicon bearing material (e.g., limestone and / or quartz); sand; clay; iron oxide; and industrial by-products such as cement kiln dust, fine concrete dust, and other construction-derived materials; or a combination thereof. The chemical composition of the feedstock may be controlled to achieve a calcium-to-silicon (Ca / Si) molar ratio in the range of about 0.5 to about 3.0. The feedstock may comprise quarry-grade or pure forms of CaCO3and SiO2. These may be derived from limestone, marble, sand, quartz, or diatomite. The feedstock may be dry-milled or otherwise micronized to achieve a fine particle size distribution (e.g., d90< 8 pm or d90< 25 pm) to ensure homogeneity and rapid reaction kinetics.

[0137] The system and / or method may comprise a low-temperature synthesis zone. In the low-temperature synthesis zone, a calcium-rich silicate feedstock may be subjected to a controlled gas-solid reaction in the presence of flowing carbon dioxide and water vapor under sub-clinkering temperatures. A non-exhaustive list of the chemical reactions in thelow-temperature synthesis zone are described in Equations (“Eq.”) (1) to (5). The resulting product is a dry, free-flowing powder comprising calcium silicate. The powder may be configured to exhibit high reactivity toward CO2.CaCO3(S) + H2O(v) — » CaHCO3'OH(S)(1)CaHCO3·OH(s)— > CaO(s)+ CO2(g)+ H2O(v)(2)Si-O-Si (Bond) + H2O(V)-> 2 Si-OH (Bond)(3)xCaO(s)+ ySiO2(s)+ H2O(v)— > CaxSiyOz(s)+ H2O(g)(4)xCaCO3(s)+ ySiO2(s)+ H2O(v)— » CaxSiyOz(s)+ CO2(g)+ H2O(v)(5)

[0138] The system and / or method may comprise a carbonation zone. In the carbonation zone, the calcium silicate powder may undergo carbonation in a continuous reactor system under low-temperature (e.g., <150 °C) conditions. The end product of the carbonation zone reaction is a silicate material. Intermittent water spraying and co-flowing CO2and water vapor may facilitate mineralization. A carbonation process may occur in the carbonation zone that may achieve high CO2uptake in a single pass, resulting in a fine agglomerated powder suitable for use as a low-carbon SCM in concrete applications. Some of the chemical reactions in the carbonation zone are described in Equations (“Eq.”) (6) to (8).CaxSiyOz(s)+ H2O(v)> (CaO)x(SiO2)(H2O)y(6)(CaO)x(SiO2)(H2O)y+ CO2(g)—» CaCO3(seed) + SiO2(pozzolan) + H2O(v)(7)CaxSiyOz(s)+ CO2(g)+ H2O(v)— CaCO3(seed) + SiO2(pozzolan) + H2O(v)(8)

[0139] The low-temperature synthesis zone and carbonation zone may enable conversion of industrial waste streams and low-grade feedstocks, and standard feedstocks into pozzolans (e.g., amorphous SiO2) while reducing energy input and reducing oreliminating reliance on high-purity CO2feedstock. The low-temperature synthesis zone may use a dry, continuous, gas-solid reaction process to synthesize a carbonation-reactive calcium silicate powder suitable for downstream CO2mineralization. The low-temperature synthesis zone may form a hot reacted product.

[0140] The system and / or method may comprise a cooling zone. Upon exiting the synthesis zone, a hot reacted product (carbonatable, non-carbonatable phases) powder may enter a cooling zone within the same reactor, where no heating elements or external heat sources are present. The cooling zone may comprise water spray or other water or aqueous solution addition to cool the product. The cooling zone may form a moist product. The moist product may be a moist calcium silicate product. Without being limited to a particular theory, moistening a calcium silicate product that comprises hydraulic phase may fully or partially convert those phases to calcium silicate-hydrate phases (C-S-H, where C is CaO, S is SiO2, and H is H2O).

[0141] The hot reacted product from low-temperature synthesis zone may be at a temperature of at least about 500 °C, about 500 °C to about 900 °C, about 625 °C to about 775 °C, about 650 °C to about 750 °C, about 675 °C to about 725 °C, or about 900 °C. The external heat sources may be present and used for a thermal profile. In the cooling zone, the powder may be exposed to an atomized fluid spray. The fluid may be water or an aqueous solution.

[0142] The sprayed fluid may reduce the powder temperature to at least about 50 °C, about 50 °C to about 200 °C, about 75 °C to about 175 °C, about 100 °C to about 150 °C, or about 200 °C. The sprayed fluid may establish a moisture content of at least about 0.01%, about 0.01% to about 33%, about 0.05% to about 30%, about 0.1% to about 25%, about 1% to about 20%, about 5% to about 15%, or about 40% by weight. The sprayed fluid may avoid particle over-wetting and / or agglomeration. The sprayed fluid may condition the powder for optimal carbonation reactivity. The sprayed fluid may convert to unsaturated steam and provide a supply of steam for the synthesis zone when a countercurrent configuration is selected. The fluid injection rate may be controlled based on powder mass flow, inlet temperature, other conditions, or a combination thereof. The system may maintain powder transport and / or prevents thermal shock via controlled fluid spray distribution and zone-specific agitation. The sprayed fluid may comprise asurfactant. The surfactant may prevent at least a portion of the agglomeration in the carbonated product. The sprayed fluid may also comprise a surfactant that accelerates carbonation.

[0143] Following cooling in the cooling zone, the moist product may enter the carbonation zone, which may be situated downstream within the same reactor. The moist calcium silicate product may be at a temperature of at least about 50 °C, about 50 °C to about 150 °C, about 75 °C to about 125 °C, or about 150 °C. The moist calcium silicate product may comprise a moisture content of at least about 0.01 wt%, about 0.01 wt% to about 40 wt%, about 0.05 wt% to about 35 wt%, about 1 wt% to about 30 wt%, about 5 wt% to about 25 wt%, about 10 wt% to about 15 wt%, or about 40 wt%.

[0144] As the hot reacted product ( / .e., powder) progresses through the reactor, it may be subjected to intermittent fluid sprays in the carbonation zone. The fluid may comprise a surfactant, an ionic surfactant, cationic surfactant, anionic surfactant, a grinding aid, a water-reducing agent, a carbonation enhancer or suppression agent, an acid, a base, ora combination therefore. The fluid spray may be calibrated to establish and / or maintain a target liquid-to-solid (“L / S”) mass ratio between about 0.05 and about 0.5.

[0145] In the carbonation zone, a gas comprising humidified carbon dioxide (CO2and H2O vapor) flows counter-current to the direction of the solid material stream. The moist product ( / .e., the powder), which may comprise a carbonation-reactive crystalline and / or amorphous calcium silicate phase, may undergo an exothermic mineralization reaction upon contact with the gas, as shown in Eq. 9, to yield a silicate material and calcium carbonate. The silicate material may be an amorphous silicate material.(CaO)x(SiO2)y + CO2+ H2O —> CaCO3+ amorphous SiO2+ H2O(9)

[0146] The carbonation zone may be configured to have sufficient residence time and physical length to ensure complete reaction. The residence time in the carbonation zone may be less than about 30 minutes, about 30 minutes to about 1 minute, about 25 minutes to about 10 minutes, about 20 minutes to about 15 minutes, or about 1 minute. Only a single carbonation cycle may be required to achieve CO2uptake into the moist product.The carbonation zone may comprise an internal flight to promote agitation of the moist product ( / .e., carbonatable powder) and enhance surface exposure to the CO2and steam atmosphere. The number, geometry, and placement of the flight may be selected based on the desired level of particle mixing and the target carbonation rate, enabling process tuning to optimize conversion efficiency within the available residence time. In the synthesis zone, the internal flight may promote agitation of the reacting feedstock powder and / or enhance CO2 displacement from the reacting powder and / or may increase surface exposure to steam within the synthesis zone. The number, geometry, and placement of the flight may be selected based on the desired level of particle mixing and / or the target synthase rate. The selection of the particle mixing and / or the target synthase rate may enable process tuning to optimize conversion efficiency within the available residence time.

[0147] For the cooling zone, the internal flight may promote agitation of the moist product ( / .e., carbonatable powder) and / or enhance surface exposure to sprayed water within the zone. Agitation promotion may increase cooling rate of hot product. The number, geometry, and placement of the flight may be selected based on the desired level of particle mixing and the targeted cooling rate. The output of the process may be a carbonate material. The carbonated material may be soft and / or agglomerated. The carbonated material may be in powder form. The carbonated material may be dried within the reactor if the carbonation zone comprises a secondary heat source. Optionally, the carbonated material may be discharged in a moist state for external drying.

[0148] The carbonated material may be subjected to a final milling or deagglomeration step to reduce the particle size distribution to a dgo of less than about 50 microns, with a mode size equivalent to that of conventional Portland cement. Suitable milling technologies include, but are not limited to, a high-shear roller mill; a ball mill; or equivalent systems capable of generating uniform, fine particles without altering the material’s chemical composition.

[0149] The system may comprise a silo configured to collect a raw material. The raw material may be metered and conveyed to a milling unit to form a feedstock. The feedstock may comprise a fine particle size distribution suitable for reactive synthesis. The feedstock may then be conveyed to a hopper and to a heat exchanger. The feedstock may be preheated using thermal energy to form a preheated solid. Preheating may beperformed by thermal energy recovered from reactor exhaust gases. The preheated solids may be fed continuously into the upstream end of the reactor.

[0150] Hot exhaust gases exiting the reactor, which may include, but are not limited to, H2S, SO2, CO2, or a combination thereof, may be directed into a gas scrubbing unit where sulfur species are removed using a reactive sorbent to form a cleaned gas stream. The cleaned gas stream may be cooled in a condenser to recover latent heat and condense a portion of water present as water vapor. The condensed water may be reused to feed a steam generator and the spray nozzles in the cooling zone. Remaining humid gas comprising CO2concentration may be conveyed to the carbonation zone to mineralize the moist product. Alternatively, the dedicated gas scrubbing unit may be partially or entirely omitted if the carbonatable material itself is employed as an in-situ sorbent. During the carbonation step in the carbonation zone, reactive calcium silicate phases may capture sulfur-containing species such as SO2and H2S, enabling concurrent CO2mineralization and sulfur removal. The majority of sulfur scrubbing may occur within the carbonation zone, leveraging the residence time and high surface reactivity of the carbonatable powder. Any residual sulfur species not captured in this step may then be removed by a downstream gas scrubbing unit, thereby providing a flexible, dual-stage scrubbing approach.

[0151] The system may comprise a steam generator. The steam generator may supply water vapor to the synthesis zone of the reactor. In the carbonation zone, the steam-enriched with CO2may be introduced counter-current to the solid flow. In the cooling zone, fluid may be deposited onto the hot reacted product. A portion of the fluid may vaporize to form steam that flows upstream into the synthesis zone.

[0152] The system may comprise a closed loop-configuration. The closed-loop configuration may reduce fluid consumption, increase heat integration, and reduce the need for external CO2inputs, compared to traditional technologies. The closed-loop configuration may enable an energy-efficient, low-emission operation.

[0153] The system and / or method may comprise a sequential dual-stage continuous process for producing carbon-sequestered supplementary cementitious material (“SCM”) through the sequential synthesis and carbonation of a reactive calcium silicate powder.The system and / or method may operate in a single-pass configuration and may not require repeated milling, hydration, or carbonation cycles.

[0154] In the first stage, a calcium-rich silicate feedstock may subjected to a controlled gas-solid reaction in the presence of flowing carbon dioxide and water vapor under sub-clinkering temperatures. The resulting product may be a dry, free-flowing powder comprising calcium silicate. The powder may be configured to exhibit high reactivity toward CO2.

[0155] In the second stage, the powder may undergo carbonation in a continuous reactor system under low-temperature (<150 °C) conditions. Intermittent water spraying and co-flowing CO2and water vapor may facilitate mineralization. The carbonation process may achieve CO2uptake in a single pass. The output of the process may be a carbonate material. The carbonated material may be soft and / or agglomerated, and in a powder form.

[0156] The dual-stage process may enable conversion of industrial waste streams and low-grade feedstocks, and standard feedstocks into pozzolans (e.g., SiO2) while reducing energy input and reducing or eliminating reliance on high-purity CO2feedstock.

[0157] The method may comprise a dry, continuous, gas-solid reaction process to synthesize a carbonation-reactive calcium silicate powder suitable for downstream CO2mineralization.

[0158] The method may comprise a carbonation reactor in which a carbonation step occurs. The powder comprising calcium silicate powder may be carbonated at nanoscale and fine agglomerates of phases in the carbonation reactor and / or step. The calcium silicate powder may be introduced into the carbonation reactor either in a dry state or in a pre-wetted condition, depending on upstream handling and process integration.

[0159] In the carbonation reactor and / or step, a gas mixture comprising humidified carbon dioxide (CO2and H2O vapor) flows co-current or counter-current to the direction of the solid material stream. The powder may undergo an exothermic mineralization reaction upon contact with the gas mixture producing solid calcium carbonate and amorphous SiO2(i.e., silicate material) (see Eq. (9)). The calcium carbonate may be in the form vaterite, aragonite, calcite polymorphs, and / or has some degree of amorphous content. The calcium carbonate may also exist as any combination of the aforementioned polymorphs and amorphous content. This combination / selection of polymorph may be dependent upon the reaction parameters chosen including, but not limited to, temperature, ratio of liquid to solid, CO2 concentration, ratio of CO2 to water vapor, the gas flow rate, carbonation time, or a combination thereof.

[0160] Carbonation may be performed in a continuous reactor system that may provide mechanical agitation and / or controlled residence time. The reactor may comprise a flexible screw tube reactor; a screw auger system; a vibratory system; a tray-based conveying system; a barrel horse system; a continuous mixing system designed for continuous powder mixing and transport; or a combination thereof. As the material progresses through the reactor, it may be subjected to a fluid spray delivered along the reactor length. The fluid may comprise a surfactant, an ionic surfactant, a grinding aid, a water-reducing agent, a carbonation enhancer or suppression agent, an acid, a base, ora combination thereof. The fluid spray may be calibrated to establish and / or maintain a target liquid-to-solid (“L / S”) mass ratio between about 0.05 and about 0.5. The fluid sprays may be calibrated to establish and / or maintain a target liquid-to-solid (“L / S”) mass ratio between about 0.05 to about 0.5. The fluid may be carbonating gas mixture comprising sufficient water for the carbonation reaction to proceed.

[0161] A gas mixture comprising CO2and water vapor may be flowed over and / or through a powder bed in the carbonation reactor. The gas stream may be recovered from the synthesis reactor. The gas recovery may reduce or eliminate the need for external or industrial CO2supply and may improve overall energy efficiency of the system. The partial pressure of CO2in the gas stream may be at least about 1%, about 1% to about 99%, about 5% to about 97%, about 10% to about 95%, about 15% to about 90%, about 20% to about 80%, about 30% to about 70%, about 40% to about 60%, or about 99%. The partial pressure of water vapor may be at least about 10%, about 10% to about 99%, about 15% to about 97%, about 20% to about 95%, about 30% to about 90%, about 40% to about 80%, about 50% to about 70%, or about 99%. The flowing gas may enhance carbonate formation by facilitating rapid surface dissolution and mineralization reactions at the solid-gas-liquid interface.

[0162] The fluid sprayed on the powder ( / .e., carbonatable reactive material) may hydrate the surface of the silicate particles, thereby enhancing carbonation reactivity (the surface may be wet, chemically hydrated, surface hydrated, physi-sorbed, chemisorbed); and act as a thermal moderator. During the cooling process the powder temperature may be at least about 40 °C, about 40 °C to about 99 °C, about 50 °C to about 90 °C, about 60 °C to about 80 °C, or about 99 °C. Thermal moderation may enable carbonation to proceed to maximum CO2uptake in a single cycle under controlled thermal conditions, reducing energy consumption and equipment cost.

[0163] The residence time in the carbonation reactor may be less than 30 minutes, about 30 minutes to about 1 minute, about 25 minutes to 10 minutes, about 20 minutes to 15 minutes, or about 1 minute. Only a single carbonation cycle may be required to achieve CO2 uptake. The output of the process is a soft, carbonated agglomerated powder with CO2 uptake ranging from at least about 20%, about 20% to about 40%, about 25% to about 35%, or about 40% by weight.

[0164] The system and / or method relate to a synthesizing and carbonating high-surface-area parawollastonite powder using conventional or quarry-grade raw materials. The method may comprise grinding a material ( / .e., feedstock) comprising calcium and silicon. The feedstock may comprise a plurality of raw materials. The feedstock may comprise a molar ratio of Ca to Si between at least about 0.3, about 0.3 to about 1.3, about 0.4 to about 1.2, about 0.5 to about 1.1, about 0.6 to about 1.0, about 0.7 to about 0.9, or about 1.3. The grinding may produce a particulate feedstock having a particle size distribution with a d90of less than about 50 pm, about 50 pm to about 1.0 pm, about 45 pm to about 10 pm, about 40 pm to about 15 pm, about 35 pm to about 20 pm, or about 1.0 pm.

[0165] Without being limited to a particular theory, water vapor may enhance the formation kinetics of calcium silicate phases at reduced temperatures and accelerate the solid-state reaction between calcium oxide (CaO) and -quartz by increasing Ca2+ion mobility and disrupting silicate networks (Si-O-Si bonds). Surface diffusion of strontium oxide (a chemical analog of CaO) on a-wollastonite and p-C2S is one to two orders of magnitude faster in humid environments, p-dicalcium silicate (p-C2S) may be synthesized from CaCO3and amorphous SiO2at 650 °C underwater vapor, whereas the sametransformation required above 800 °C in dry air. Water vapor facilitates both bulk and surface diffusion through ionic mobility and surface activation, enabling more efficient, lower-temperature synthesis of calcium silicate materials.

[0166] The feedstock may be desulfurized. Desulfurizing the feedstock may be performed if the feedstock comprises sulfur-bearing compounds.

[0167] The method may comprise disposing the feedstock into a reactor to form parawollastonite powder. The feedstock may be subjected to a temperature of at least about 500 °C, about 500 °C to about 900 °C, 550 °C to about 850 °C, 600 °C to about 800 °C, 650 °C to about 750 °C. The parawollastonite powder may be subjected to a flowing gas atmosphere comprising CO2 and / or H2O vapor. The water-to-solid mass ratio in the reactor may be at least about 0.1, about 0.1 to about 8, about 0.5 to about 7.5, about 1 to about 7, about 2 to about 6, about 3 to about 5, or about 8. The total system pressure may be at least about 0.1 atmospheres, about 0.1 atmospheres to about 60 atmospheres, about 1 atmospheres to about 50 atmospheres, about 10 atmospheres to about 40 atmospheres, about 20 atmospheres to about 30 atmospheres, or about 60 atmospheres.

[0168] The system and / or method may comprise maintaining a residence time. The residence time may be less than about three hours. The reactor may produce a dry, free-flowing reacted powder. The reacted powder may comprise parawollastonite (wollastonite-2M) crystals and other carbonatable calcium silicate phases including, but not limited to, spurrite, kilchoanite, a’- and g- and p-C2S, amorphous phases (e.g., a silica amorphous face, silicate amorphous phase, and / or pozzolanic amorphous phase), and non-carbonatable components. The powder may also comprise non-calcium silicate phases; inert reactants; newly formed products that may be reactive of inert; or a combination thereof. The reacted product is a carbonatable material. The carbonatable material may be considered as engineered for high carbonation reactivity and may be suitable for conversion into CO2-sequestered SCMs with short residence times in subsequent processing. These engineered high-carbonation-reactivity material characteristics include, but are not limited to, the total content of carbonatable phases; the proportion of calcium silicate species with high carbonation affinity (such as p-C2S); the resulting particle size distribution; specific surface area; degree of agglomeration of a synthesized powder; ora combination thereof.

[0169] The method may comprise cooling evolved CO2-H2O vapor to below 150 °C. The method may comprise condensing at least a portion of the water vapor and / or enriching the CO2concentration in the gas phase. Cooling the evolved CO2-H2O vapor may produce a conditioned gas stream. The conditioned gas stream may then be used in a carbonation step for reacting with the carbonatable material.

[0170] The method may comprise carbonating the carbonatable material. The carbonatable material may be carbonated in a single pass by contacting the carbonatable material with cooled CO2and water vapor gas stream. The temperature of the cooled CO2and water vapor gas stream may be at least about 40 °C, about 40 °C to about 150 °C, about 50 °C to about 140 °C, about 60 °C to about 130 °C, about 70 °C to about 120 °C, about 80 °C to about 110 °C, about 90 °C to about 100 °C, or about 150 °C. Carbonating the carbonatable material may produce a synthesized product. The synthesized product may comprise a high surface area (e.g., >6 m2 / g) and nanoscale morphology. The high surface area and nanoscale morphology of the synthesized product may enable rapid and complete carbonation without forming core-shell structures typical of natural and synthetic wollastonite micro-sized powders. The synthesized product may be the output of the synthesis reaction before cooling step. Certain phases (e.g., a’- and p-C2S) of the synthesized product may convert into calcium silicate-hydrate phases (called C-S-H) upon reaction with sprayed water. The final product is an SCM post carbonation.

[0171] The system and / or method may operate in either a batch and / or continuous mode. In the continuous mode, the reactor may comprise a rotary kiln or an equivalent flow-through reactor adapted for sustained operation. The reactive gas stream may be introduced in either a co-current or counter-current flow orientation relative to the solid feedstock. The gas-to-solid mass flow ratio may be maintained in a range of at least about 0.1, about 0.1 to about 8, about 0.5 to about 7.5, about 1 to about 7, about 2 to about 6, about 3 to about 5, or about 8. The partial pressures of CO2and H2O vapor in the gas phase may independently range from 0.1% to 99% by volume.

[0172] The reactor may be thermally controlled to operate within a temperature range of at least about 500 °C, about 500 °C to about 1,000 °C, about 550 °C to about 950 °C, about 600 °C to about 900 °C, about 650 °C to about 850 °C, about 700 °C to about 800 °C,or about 1,000 °C. The temperate of the reactor may promote phase formation and chemical reactions among feedstock constituents.

[0173] The gas-to-solid ratio and residence time may be selected to ensure complete reaction in under three hours. Steam may be applied to the feedstock and may act as a diffusion facilitator. The steam may disrupt silicate networks and enhance Ca2+mobility within the feedstock. Elevated pressure applied to the feedstock may enhance solid-state diffusion and / or favor wollastonite formation at a temperature lower than about 900 °C, about 900 °C to about 100 °C, about 800 °C to about 200 °C, about 700 °C to about 300 °C, about 600 °C to about 400 °C, or about 100 °C.

[0174] The method may comprise a gas-solid reaction, i.e., synthesis step. The gassolid reaction may produce a dry, free-flowing synthesized product. The synthesized product may not be agglomerated or may have any degree of agglomeration. The synthesized product may comprise hydraulic and non-hydraulic calcium silicate phases; amorphous calcium silicates; amorphous pozzolanic material; non-carbonatable or CO2-inert components; or a combination thereof. The synthesized product may comprise a crystalline phase. The crystalline phase may include, but is not limited to, pseudowollastonite, p-wollastonite, p-, a’-, and y-dicalcium silicate (C2S), rankinite, kilchoanite, spurrite, reinhardbraunsite, ora combination thereof.

[0175] The gas-solid reaction yield may range from at least about 10%, about 10% to about 100%, about 20% to about 90%, about 30% to about 80%, about 40% to about 70%, about 50% to about 60%, or about 100%. The gas-solid reaction products may be a material comprising an amorphous phase content. The amorphous phase content may be at least about 1%, about 1% to about 100%, about 5% to about 95%, about 10% to about 90%, about 20% to about 80%, about 30% to about 70%, about 40% to about 60%, or about 100% by weight. The carbonatable product may be an engineered material configured for high carbonation reactivity and which may be well-suited for conversion into CO2-sequestered supplementary cementitious materials (“SCM”) under short residence times (e.g., less than three hours) in downstream processing.

[0176] The method may comprise discharging the carbonatable material from the reactor and cooling the carbonatable material. The carbonatable material may be cooledto less than about 100 °C, about 100 °C to about 0 °C, about 80 °C to about 20 °C, about 60 °C to about 40 °C, or about 0 °C. Once the reaction is complete, the carbonatable material may be discharged from the reactor. In batch operation, the reactor may be cooled to room temperature prior to removing the synthesized product. In continuous operation, the synthesized product may be discharged from the outlet of the reactor. Upon exiting the synthesis zone, the hot reactant product (comprising carbonatable and non-carbonatable phases at 600 °C to 800 °C) enters a cooling chamber. The chamber may be a rotary tube. The hot reactant product may be contacted with an atomized fluid spray to yield a moist product. The sprayed fluid may reduce the hot reactant product temperature to at least 50 °C, about 50 °C to about 200 °C, about 75 °C to about 175 °C, about 100 °C to about 150 °C, or about 200 °C. The moisture content of the moist product may be at least about 0.01%, about 0.01% to about 33%, about 0.05% to about 30%, about 0.1% to about 25%, about 1% to about 20%, about 5% to about 15%, or about 33% by weight. The water injection rate may be controlled based on powder mass flow, inlet temperature, and desired exit conditions.

[0177] Following the cooling step, the moist product may be carbonated within a carbonation chamber. The carbonation chamber may be at a temperature of at least about 50 °C, about 50 °C to about 120 °C, about 60 °C to about 110 °C, about 70 °C to about 100 °C, or about 120 °C. When the moisture of cooled product (before carbonation) is about less than 5 wt %, the moist product may be subjected to an intermittent fluid spray applied in specific locations along the carbonation chamber.

[0178] In continuous operation, a gas mixture comprising humidified carbon dioxide (CO2and H2O vapor) may flow counter-current to the direction of the solid material stream. The parawollastonite powder may undergo an exothermic mineralization reaction upon contact with the gas. The exothermic mineralization reaction may yield a silicate material. The silicate material may be an amorphous silicate material.

[0179] The carbonated powder may be subjected to a final milling or deagglomeration step after the carbonation step to reduce the particle size distribution of carbonated material to a d90of less than about 50 microns, with a mode size equivalent to that of conventional Portland cement. Suitable milling technologies include, but are not limited to, high-shear roller mills, ball mills, equivalent systems, or a combination thereof. The millingtechnology may be configured to generate uniform, fine particles without altering the material’s chemical composition.

[0180] Owing to its high reactivity with carbon dioxide (CO2), the moist product requires no chemical activation or the use of carbonation catalysts to achieve efficient CO2uptake. Optionally, the method may comprise using carbonation catalysts (e.g., oxides of iron (Fe), titanium (Ti), cobalt (Co), nickel (Ni), ruthenium (Ru)), carbonation enhancers (e.g., triethanolamine, dicarboxylic acids such as succinic acid, adipic acid, and acetic acid and their salts, vinegar), and carbonation retarders (e.g., sugars, citric acids and its salts). The carbonation yield may be at least about 5%, about 5% to about 100%, about 10% to about 90%, about 20% to about 80%, about 30% to about 70%, about 40% to about 60%, or about 100%.

[0181] To optimize reactivity and phase formation, the feedstock is milled or otherwise processed to a particle size distribution with a dgo of less than about 50 microns. The finely ground feedstock may be continuously disposed into a high-temperature reactor. The high-temperature reactor may include, but is not limited to, an electrified rotary kiln, tubular flow reactor, a similar apparatus configured for continuous operation under controlled conditions; or a combination thereof.

[0182] Within the reactor, the powder may be exposed to a flowing gas stream comprising carbon dioxide (CO2) and water vapor (H2O), wherein the gas may be flowed in a co-current or counter- current direction relative to the flow of the solid feedstock. The gas-to-solid mass flow ratio may be maintained from at least about 0.01, about 0.01 to about 4.0, about 0.05 to about 3.5, about 0.1 to about 3.0, about 1.0 to about 2.5, about 1.5 to about 2.0, or about 4.0. The partial pressures of CO2and H2O may each range from at least about 0.1%, about 0.1% to about 100%, about 1% to about 75%, about 5% to about 50%, about 10% to about 25%, about 25% to about 100% about 50% to about 75%, or about 100%. The overall system pressure may be at least about 0.5 atmospheres, about 0.5 atmospheres to about 2 atmospheres, about 1 atmosphere to about 1.5 atmospheres, or about 2 atmospheres.

[0183] The heat released from this exothermic reaction contributes to maintaining the zone temperature within a range of at least about 50 °C, about 50 °C to about 150°C, about 60 °C to about 140°C, about 70 °C to about 130°C, about 80 °C to about 120°C,about 90 °C to about 110°C, without the need for external heating. This temperature profile may enable complete or near-complete conversion of carbonatable phases to calcium carbonate (CaCO3) and amorphous silica (SiO2). The CO2 uptake may be at least about 25%, about 25% to about 40%, about 30% to about 35%, or about 40% by weight in a single pass.

[0184] If the feedstock contains sulfur-bearing compounds such as pyrite (FeS2), an optional desulfurization step may be performed upstream of the reactor. In this step, the feedstock is exposed to flowing air at a temperature of about 400 °C to about 800 °C and an air-to-solid mass ratio ranging from about 0.1 to about 3.0. The duration of this step may be 30 minutes or less. Alternatively, if desulfurization is omitted, evolved sulfur gases, such as SO2and H2S, may be removed downstream using a gas scrubbing system comprising reactive sorbents. The sorbent may include, but is not limited to, zinc oxide (ZnO), calcium carbonate, calcium hydroxide, lime, cement raw meal, carbon-reactive calcium silicates, a zeolite metal organic framework (“MOF”), or combination thereof.

[0185] Alternatively, the gas scrubbing unit may be partially or entirely omitted if the carbonatable material itself is employed as an in-situ sorbent. During the carbonation step, reactive calcium silicate phases can capture sulfur-containing species such as SO2and H2S, enabling concurrent CO2mineralization and sulfur removal. The sulfur scrubbing may occur within the carbonation zone and may leverage the residence time and / or high surface reactivity in the form of chemisorption; physisorption; other forms of reactivity via the carbonatable and / or carbonated powder; or a combination thereof. Any residual sulfur species not captured in this step may then be removed by a downstream gas scrubbing unit.

[0186] The product from the synthesis step may comprise hydraulic and non-hydraulic calcium silicate phases, amorphous calcium silicates, non-carbonatable orC02-inert components. The crystalline phases may include, but are not limited to, -, a-, and y-dicalcium silicate (C2S); rankinite; kilchoanite; spurrite; reinhardbraunsite; wollastonite; pseudowollastonite; ora combination thereof.

[0187] The system and / or method may comprise a controlled gas-solid reaction in a continuous process environment. The system and / or method may comprise a plurality of subsystems (e.g., equipment or components). The subsystems may operate incoordination to produce a mineralized powder product suitable for use as a supplementary cementitious material (“SCM”).

[0188] The system may comprise a material handling subsystem. The material handling subsystem may facilitate continuous or semi-continuous feeding of dry, reactive material into a reactor. The material handling subsystem may facilitate the removal of carbonated product from the system. The material handling subsystem may comprise a hopper, feeder, screw conveyor, airlock, discharge mechanism, or a combination thereof.

[0189] The carbonation or mineralization process may occur in the reactor ( / .e., mineralization vessel). The reactor may enable contact between the reactive powder (i.e., silicate and / calcium silicate material), steam, and / or CO2. The contact may occur under controlled temperature, residence time, moisture conditions, ora combination thereof. The contact may be a synthesis reaction.

[0190] The system may comprise a steam and process gas delivery subsystem. The steam and process gas delivery subsystem may regulate the flow, composition, pressure, temperature of gaseous reactants, or a combination thereof into the mineralization vessel. The gaseous reactants may comprise steam, carbon dioxide, another other gas, or a combination thereof. The steam and process gas delivery subsystem may comprise a heater, steam generator, flow controller, pressure regulator, gas mixing unit, or a combination thereof.

[0191] The system may comprise a water spray subsystem. The water spray subsystem may introduce liquid water into the reactor. Introduction of liquid water may ensure that the material achieves and / or maintains a specified moisture content and temperature range for carbonation reactivity. The water spray subsystem may control spray rate, droplet size, timing, or a combination thereof.

[0192] The subsystems may enable control over process parameters required for carbonation. The mineralization process may be carried out at temperatures ranging from at least about 60 °C, about 60 °C to about 90 °C, about 65 °C to about 85 °C, about 70 °C to about 80 °C, or about 90 °C. The residence time may be at least about one, about one to about ten, about two to about nine, about three to about eight, about four to about seven,about five to about six, or about ten minutes. The concentration of carbon dioxide within the reactor ( / .e., mineralization vessel) may be maintained between at least about 20%, about 20% to about 80%, about 30% to about 70%, about 40% to about 60%, or about 80% by volume. To facilitate efficient carbonation, the moisture content of the feed material may be controlled within a range of at least about 10%, about 10% to about 40%, about 15% to about 35%, about 20% to about 30%, or about 40%. The final product may be dried to achieve a residual moisture content of at least about 0%, about 0% to about 3%, about 0.5% to about 2.5%, about 1% to about 2%, or about 3%.

[0193] The system may be configured using a mineralization technology. Each mineralization technology may be configured to transport and agitate powder materials while exposing them to the reactive gas environment. The mineralization technology may be a screw, auger, paddle mixer, paddle mill technology; other stirred mill technology; ball mill or other media-based mill technology; and a vibro-energy mill or barrel-horse mill technology.

[0194] Each mineralization technology may be deployed in two configurations: a base configuration for standard carbonation processes; or an enhanced configuration comprising additional equipment and / or control features fortuning final product specifications such as particle size, particle size distribution, residual moisture in carbonated material, CO2uptake, or a combination thereof.

[0195] The system may comprise a flexible and / or modular architecture that may accommodate different material chemistries, processing capacities, integration scenarios, or a combination thereof. The flexible and / or modular architecture may allow the system to be suitable for operation at any scale.

[0196] The system comprising a screw, auger, paddle mixer, and / or paddle mill technology may enable rapid mineralization of reactive powders (e.g., silicate and / or calcium silicate material). The reactor reaction time may be at least about 3, about 3 to about 30, about 5 to about 25, about 10 to about 20, or about 30 minutes. The carbonatable material may introduced into the system via a feeder, if used as a standalone unit, or through a hopper fed by an upstream process. The carbonatable material may be metered into the reactor through a rotary airlock and / or a double dump valve. The systemmay preserve a controlled internal atmosphere inside the reactor. Once inside the reactor, the carbonatable material may be conveyed through the reactor by mechanical means, which may include, but is not limited to, a solid or hollow flight screw; an auger; a paddle mixer; a pug mill shaft; or a combination thereof.

[0197] The system may be configured to integrate a conveyance technology depending on the physical and rheological properties of the carbonatable material; the required level of moisture homogenization; the desired physical, chemical, and rheological attributes of the final carbonated product; or a combination thereof. For example, a highspeed pug mill with spinning plates may be used when both particle size reduction and rapid moisture blending are needed. Slower-speed paddle mixers may be used for gentler mixing to achieve uniform moisture distribution without significant particle breakdown.

[0198] A thermal control jacket may be installed around the reactor to maintain stable material temperatures throughout the carbonation process, using active heating or cooling elements as needed. Given the exothermic nature of the carbonation reaction, thermal regulation may prevent excessive heat buildup that may lead to premature moisture loss from the carbonatable material blend, thereby hindering reaction completeness.Carbonation may occur over a temperature range of at least about 40 °C, about 40 °C to about 99 °C, about 50 °C to about 90 °C, about 60 °C to about 80 °C, or about 99 °C. The CO2uptake may maximized (e.g., 25 wt% to 35 wt%) in a short residence time (e.g., <30 minutes) under a single-pass processing condition. Operation at lower temperatures may be possible but may result in slower carbonation kinetics and longer processing times.

[0199] A plurality of fluid spray nozzles may be integrated into the reactor to support thermal regulation and / or maintain optimal moisture levels within the moving carbonatable powder bed. The fluid spray nozzles may deliver water as fine mists and / or atomized droplets directly onto the moving carbonatable material. The fluid spray nozzles may enable adjustment of material moisture content and / or aiding in temperature control within a given operating range. The fluid spray may suppress entrainment of fine particles in the gas stream (CO2and water vapor) flowing through the reactor. The fluid spray may enhance operational control over the carbonation process and product consistency.Product consistency refers to the consistency in extent of CO2uptake and presence of desired pozzolanic phase in the carbonated product.

[0200] A gas stream comprising steam and / or CO2may be injected in a countercurrent flow relative to the material movement as the carbonatable powder advances through the reactor from the feed point to the discharge end. The temperature, flow rate, and steam-to-CC>2 ratio of the gas stream may be controlled to achieve process conditions that enable rapid carbonation (e.g., less than about 30 minutes) with CO2uptake. The injected gas steam may be saturated or superheated. The temperature and partial pressure of the injected gas stream may be affected by the moisture content of the material and / or the target extent of carbonation. The temperature and partial pressure of the injected CO2may be affected by the moisture content of the material and / or the target extent of carbonation. The process conditions may comprise a steam partial pressure of at least about 10%, about 10% to about 70%, about 20% to about 60%, about 30% to about 50%, or about 60%; a CO2partial pressure of at least about 10%, about 10% to about 70%, about 20% to about 60%, about 30% to about 50%, or about 60%; and a total gas pressure of less than two atmospheres. The steam temperature ranges from at least about 70 °C, about 70 °C to about 800 °C, about 100 °C to about 700 °C, about 200 °C to about 600 °C, about 300 °C to about 500 °C, or about 800 °C. For example, the CO2partial pressure and its flow rate fall in the range of is about 30% to 69% and 340 gCO2 / kg of carbonatable material, respectively.

[0201] The residence time of the carbonatable material within the carbonation vessel may be controlled through the configuration of the screw or paddle system including, but not limited to, flight geometry, pitch, and length, as well as by adjusting the rotation speed of the drive motor. These parameters may allow for precise regulation of material throughput and ensure adequate exposure of the reactive powder to the steam and CO2gas stream for effective carbonation.

[0202] The system may comprise a control system module. The control system module may continuously monitor and / or adjust operation parameters to maintain process quality. The control system module may comprise an array of sensors to track real-time operating conditions, including thermocouples, hygrometers, a CO2sensor, a SO2sensor, a H2S sensor, an RPM sensor, a flow meter, a vibration sensor, or a combination thereof.

[0203] The system may comprise a thermocouple. The thermocouple may be of any suitable type, such as a standard K-Type thermocouples. The primary selection criterion may be the sheath material. The sheath material may be chemically compatible with theprocess environment to prevent degradation overtime. Depending on the overall length of the reactor, a plurality of thermocouples may be installed along its axis. The plurality of thermocouples may be spaced at intervals and may provide an accurate temperature profiling throughout the system.

[0204] The system may comprise a hygrometer. The hygrometer may be disposed at any step in the method. The hygrometer may monitor a humidity condition in the system. As fluid is sprayed onto the carbonatable material, the steam concentration may be balanced with the incoming gas flow. Balancing the steam concentration with the incoming gas flow may ensure that the material is not being over saturated with fluid. When the local humidity approaches saturation, the amount of fluid sprayed may reduce until excess steam is vented from the system. Venting the excess steam may ensure proper moisture control and consistent carbonation performance.

[0205] The system may comprise a gas sensor. CO2 and other gas sensors may be installed at any step in the method or at any component of the system to monitor the progress of the mineralization reaction. Comparing the inlet and outlet CO2concentrations, the system may assess the extent of carbonation occurring within the reactor. This data is used by the control system to optimize process conditions. For example, the fluid spray rate may be adjusted affect reaction kinetics. Additionally, the residence time may be modified by varying material feed rate and / or rotational speed. Varying the material feed rate and / or rotational speed may ensure maximum CO2uptake within the shortest possible duration.

[0206] The system may comprise an RPM sensor. The RPM sensor may provide real-time feedback to the control system on the rotational speed of the shaft. This data may be used to calculate material flow rate and / or determine residence time of the material within the system. Calculating material flow rate and / or determining residence time of the material within the system may enable accurate control of the carbonation process.

[0207] In case of the vibratory systems, a vibration sensor may provide real-time feedback on the frequency of system oscillation. As the system fills with material and process gases, the increased mass may dampen the required vibration intensity, and may affect conveyance and mixing efficiency. The sensor may monitor the vibration frequency and transmits this data to the control system, which may then adjust the motor input tomaintain the desired vibration amplitude and frequency. Adjusting the vibration frequency may ensure consistent process performance.

[0208] Finally, flow meters and flow controllers may be used to measure and regulate the flow rate of CO2and other process gases as they are injected and exhausted from the system. When combined with data from in-line gas sensors, this information may be used to optimize system performance. Controlled gas flow may improve product quality because injecting too much or too little CO2may negatively impact reaction kinetics and while improper exhausting gas composition and concentration may reduce process efficiency or result in non-compliance with environmental regulations. The control system may use these measurements to dynamically adjust gas inputs and maintain optimal operating conditions throughout the carbonation process.

[0209] In the expanded implementation of the screw, auger, or paddle mixer / mill system, a plurality of units may be arranged in tandem to provide enhanced control over the carbonation process, improve material handling flexibility, enable precise adjustment of final product specifications; or a combination thereof. As in the base configuration, all process parameters including, but not limited to, temperature, residence time, gas composition, moisture content, or a combination thereof may be actively controlled.However, the tandem arrangement allows each stage to be independently optimized, offering greater precision in tuning carbonation kinetics and tailoring the physical and chemical properties of the carbonated material. The expanded tandem use of the screw, auger, or paddle mixer / mill system may enable significantly higher CO2uptake and more complete mineralization compared to a system with a single reactor.

[0210] The initial mineralization vessel may operate at lower moisture content to rapidly achieve partial carbonation (for example, about 10% to about 60% of the total CO2uptake) under conditions that help control particle size and reduce agglomeration. The material may then be transferred to subsequent vessels for completion of the carbonation process under conditions optimized for full reaction. This phased approach may enhance total CO2uptake and / or allow control over the morphology and agglomeration state of the product, which may simplify downstream processing steps such as milling or classification. The expanded system may reduce the energy demand and complexity of post-carbonationoperations by enabling tailored physical and chemical characteristics of the carbonated material.

[0211] Each stage within the expanded system may employ different conveyance technologies to serve specific functional roles. For instance, the first unit may comprise a high-speed pug mill to breakdown agglomerates and initiate mixing with water, while concurrently introducing CO2 and steam to begin the carbonation reaction, only partial carbonation may occur due to the short residence time in this stage. The material may then flow into a second unit, such as a low-speed paddle mixer, which may provide a longer residence time and gentle mixing to complete the carbonation process under stable conditions. This sequential, multi-stage design results in a more fully mineralized supplementary cementitious material (“SCM”), contributing to higher overall CO2reduction when incorporated into cementitious formulations.

[0212] A ball mill or other media-based mill may be utilized to carry out both the mineralization reaction and particle size reduction in a single, integrated operation.Material may be introduced into the system via a feeder in standalone configurations or through a hopper fed by an upstream process. To maintain a controlled atmosphere within the mineralization chamber, the carbonatable material may be metered into the reactor through a rotary airlock and / or double dump valve.

[0213] The main chamber of the carbonation reactor may be at least partially filled with a grinding media. The grinding media may facilitate mechanical mixing and / or comminution of the material. The material may be incoming carbonatable feed and / or the partially or fully carbonated product. Concurrent milling may reduce particle size; break down soft agglomerates; expose fresh reactive surfaces to the steam and CO2environment; or a combination thereof. Concurrent milling may accelerate carbonation kinetics. The reactor may rotate similarly to a conventional ball mill and may ensure consistent agitation of the powder-media mixture. The rotational speed may be slower than, equivalent to, or greater than that used in traditional ceramic powder milling. The milling action may reduce the size of incoming particles and / or disrupt agglomerates that may form during carbonation. The milling action may improve material consistency.

[0214] A counter-current flow of steam and CO2may be introduced relative to the direction of material flow, enabling maximum gas-solid interaction. Temperature sensors may be disposed along the reactor length and / or width. The temperature sensors may provide real-time thermal feedback. Spray nozzles may inject fine fluid mist to regulate powder moisture content and / or prevent thermal runaway during the exothermic reaction. As the carbonation reaction proceeds and CO2 is consumed, excess steam may be vented and replaced with fresh gas inputs to maintain desired operating conditions. The temperature and / or composition of the incoming gas stream may also be adjusted to control the residual moisture content of the product exiting the system.

[0215] The system may comprise a thermal control jacket. The thermal control jacket may surround the reactor vessel to provide additional heating or cooling capacity, enabling temperature regulation throughout the system and / or method. Residence time within the reactor may be controlled by the angle of inclination of the rotating chamber and its rotational speed (“RPM”), both of which influence material retention time and mixing intensity within the system.

[0216] The expanded implementation of the ball mill or other media mill mineralization system may comprise a plurality of tandem milling units and / or segmented chambers arranged in series. This configuration may provide greater control over both the carbonation process and the physical characteristics of the final product than a system comprising a single milling unit. By segmenting the system into discrete stages, each with its own media specifications and operating conditions, the process may be tuned to optimize particle size reduction and / or carbonation kinetics.

[0217] For example, the first chamber may contain larger grinding media, such as 10 mm diameter balls, which are effective at breaking down coarse particles and reducing the carbonatable material to an intermediate particle size. As the material undergoes partial mineralization in this chamber, it is then conveyed to a second chamber for a secondary grinding step. The second chamber may contain smaller media (such as three millimeter balls) selected to further reduce particle size and / or expose additional reactive surface area. The secondary grinding step enhances carbonation kinetics and / or smooths particle morphology by eliminating the rough surfaces created during the initial comminution phase.

[0218] By selecting the grinding media size, sequencing the chamber operations, and adjusting residence time in each stage, the system may control the particle size distribution, extent of carbonation, and consistency of the final carbonated product. This level of process control may produce a high-performance supplementary cementitious material (“SCM”) with predictable and optimized properties for downstream cement blending applications.

[0219] The vibro-energy mill shares structural similarities with a conventional ball mill but operates through a fundamentally different mechanism for milling and mixing. Instead of relying on rotational motion, the vibro-energy mill uses high-frequency vibratory motion to agitate the grinding media and the carbonatable material. The reactor shell remains stationary, while vibratory forces induce rapid and multidirectional media movement throughout the chamber of the reactor.

[0220] Compared to traditional ball mills, the vibro-energy mill imparts higher and more uniform energy to the material. Whereas a ball mill relies on gravity to lift and drop the media (limiting particle-to-media interactions based on mill diameter, ball size, and rotational speed), the vibro-energy mill provides continuous, high-frequency collisions. This allows for an increase in particle-to-media contact frequency and may enhance surface activation and / or improve mineralization kinetics.

[0221] The intensity of milling may be tuned by adjusting the vibration amplitude and / or frequency. Tuning may allow for control over the energy input and / or degree of comminution. Adjusting the vibration amplitude and / or frequency may allow rapid exposure of fresh surfaces for carbonation and supports high reactivity of the final product.

[0222] As with other implementations, residence time may be controlled by modifying the vibration frequency, adjusting the inclination angle of the vessel, altering the length of the processing chamber; or a combination thereof. These variables may collectively ensure that the desired degree of carbonation and particle size distribution is consistently achieved.

[0223] The expanded implementation of the vibro-energy mill system may comprise a plurality of subunits arranged in series. The subunits arranged in series may offer the same advantages as the tandem configuration described for the ball mill mineralizer. Thismulti-stage arrangement may allow for enhanced control over the mineralization process by enabling different operational conditions in each chamber. Grinding media of varying sizes may be deployed in separate subunits, and each chamber can be configured with different lengths and vibration frequencies. Adjustable parameters may serve as control levers for fine-tuning particle size distribution, optimizing surface activation, achieving precise final product specifications; or a combination thereof. The modular and / or sequential design may improves flexibility, process efficiency, consistency in producing high-performance carbonated materials; or a combination thereof.

[0224] A system for a reactor system used for HVRP and / or steam-based processing may comprise a material infeed system, a main reaction vessel, a material outfeed system, a reactor heating system, and gas delivery and removal system. The system may comprise an internal material handling system, or the reaction vessel could be otherwise configured / customized to facilitate movement and / or mixture of material within the reaction vessel. The system may comprise a heating system or multiple subsystems to facilitate managing temperature conditions during a reaction.

[0225] The material infeed system functions to move material into the reactor. The material infeed system may comprise material handling equipment that moves material from a hopper, silo, and / or other material source and feeds it into the reactor. The material infeed system may help the reactor achieve consistent feedstock material flow during material processing within the reactor.

[0226] The main reaction vessel functions as the container in which material undergoes partial and / or full processing. The main reaction vessel may comprise a defined reaction chamber or region in which material is contained while conditions are established for processing of the material. The main reaction vessel may comprise various specialized equipment and / or subsystems that may be specially designed for optimal / enhanced HVRP processing to ensure chemical reactions occur as desired. Various types of reactor vessels may be used to operate in various modes including, but not limited to, a fluidized bed reactor, calciner, flash calciner, cyclone suspension heater, rotary kiln, thermal screw conveyor, autoclave configured reaction vessels, or a combination thereof.

[0227] The system may comprise a single reaction vessel in which full processing of material is performed. The system may comprise a set of reaction vessels, which may be interconnected and used in tandem or in parallel. Reaction vessels of the set of reaction vessels may be substantially similar in the type of reaction vessel. Subsets of the set of reaction vessels may use different variations.

[0228] Depending on configuration, the reaction vessel may be horizontal, inclined, or vertical depending on implementation. The reaction vessel may also be rotating to allow the material inside to tumble to increase heat transfer and allow for material to propagate along the reactor from inlet to outlet. The reaction vessel may also be rotating at a horizontal orientation, without material propagation from inlet to outlet to increase residence time in the desired reaction zone. The degree of inclination may be varied as a function of reaction time.

[0229] The main reaction vessel depending on the design variation may comprise one or more different internal material handling systems which facilitate movement of material through the reaction vessel. The main reaction vessel may additionally comprise one or more reactor heating systems that are integrated into part or all of the reaction vessel.

[0230] The material outfeed system functions to move material out of the reactor. The material coming out of the reactor is preferably partially or fully processed, having undergone chemical processing within the reactor. The material outfeed system may comprise material handling equipment that moves materials into a hopper, silo, and / or other system for receiving the material. The material outfeed system may remove material from one reactor and facilitate transport of the altered material to another processing system such as another reactor.

[0231] The reactor heating system functions to heat the material / environment in the defined chamber of the reactor vessel. The reactor heating system may be integrated into the main reaction vessel. The reactor heating system may internally or externally manage temperature for the chemical reactions to occur. The heating system may be integrated and applied within a shell or body of the reaction vessel. The heating system may beintegrated into an internal material handling system such as an internal screw or material agitation elements.

[0232] The gas delivery and removal system functions to manage controlling introduction of gaseous materials into the environment of the reaction vessel. The gas delivery and removal system can supply the process gases that are used to catalyze a targeted reaction (e.g., the reaction of HVRP). Different variations may work better with different system designs (e.g., different main vessel variations), processing methods, and / or different types of material end-products. A non-exhaustive list of gases that may be delivered and / or removed from the system including, but not limited to, superheated steam, saturated steam, pressurized steam, unsaturated steam, carbon dioxide, nitrogen, air, oxygen, or a combination thereof.

[0233] The system may comprise a control system and / or sensing system for managing and / or monitoring processing of materials. The sensing system may provide one or more data points on the operation of the system such as temperature, pressure, material feed quantifications, and / or other inputs including residence time control by adjusting variables such as, non-exhaustively, the speed of rotation and / or the degree of inclination. The control system can manage the operation of the system components for producing materials according to desired conditions for the targeted chemical process. Additionally, the system for the reactor may be integrated into different production systems and / or used as a component of larger production systems.

[0234] The subsystems and variations of the systems and methods described herein may be combined into multiple unique configurations that may have different advantages and disadvantages. Herein are described eight unique reactor design variations. Along with these system variations are different processing variations which may be similarly used in different combinations.

[0235] The system will may operate at targeted temperature, pressure, gas atmosphere, and residence time ranges dependent on the product being produced. The system operates at a temperature between about 20 °C to about 1000 °C. The system may maintain a pressurized atmosphere between about 1 atmosphere to about O atmospheres within the main reaction vessel during material processing. This pressurizedatmosphere will be monitored and maintained with a targeted ratio of desired gases. Such gases managed within the pressurized atmosphere may include, but are not limited to, steam, CO2, N2, air, ora combination thereof. The material being fed into the reactor may be processed for enhancing / optimizing for reaction kinetics and product yields. For example, material inputs can be in the form of powders, powder blends small or large solid mineral chunks, aggregates, briquettes, pellets, and others.

[0236] With HVRP and steam-based processing the material may have a targeted residence time within the reactor for some time period that is defined based on the targeted product production process being implemented within the reactor.

[0237] The system may comprise a plurality of heating methods and sources. The system may comprise adjustable processing parameters. The system may be preconfigured with set targeted operating parameters. Heating methods utilizing a working fluid may be run either on fossil fuels or on electricity. Direct heating, such as a heatsource (e.g., direct fuel burner, fuel combustion, hydrogen combustion, electric heating, hot gas) located inside the reactor to heat from within, or indirect heating with a heat-source located outside of the reactor (e.g., heating the reactor shell to propagate heat inside the reactor). Direct heating may also use a wide variety of fuel sources including, but not limited to, a direct fuel burner, fuel combustion, hydrogen combustion, electric heating, hot gas, or a combination thereof. The selection of the heating method may be dependent on the availability of energy sources where a reactor is installed and desired operation

[0238] Environmentally clean energy sources may also be used to provide the heating to a working fluid or direct electrical heating. These sources include, but are not limited to, waste-heat, geothermal heat, solar thermal heat, hydrogen combustion, wasteheat, geothermal heat, solar thermal heat, hydrogen combustion, or a combination hereof.

[0239] The following design variations are examples of systems that control and optimize one or more of these requirements. All of the designs allow for residence time control, and energy efficiency (due to lower temperatures and electric heating)

[0240] The system may comprise a stationary shell (e.g., the outer body of the reaction vessel) and a moving screw. Such a configuration may enable fine tune control ofthe gas input, gas removal, material propagation, and / or kinetics (heat addition or removal with multiple heat zones) to manage the chemical reaction process.

[0241] The gas delivery and / or removal system may comprise multiple gas injection and gas removal points within the main reaction vessel. The gas injection and gas removal points may be distributed along the length of the reaction vessel. The system gas injection and gas removal points may be localized along different zones that can be optimized for the specific atmospheric composition desired by the zone. Specific temperatures and gas flow rates may be set in each zone to optimize kinetics.

[0242] The screw material handling system preferably rotates about an axis defined along or in the direction of the length of the reaction vessel (e.g., between two points between entry of the material from material infeed system and dispensing of material from the material outfeed system. A screw material handling may comprise one or more helical forms that can be rotated to promote motion of material through the reaction vessel. The screw system may alternatively be referred to as or include an auger mechanism.

[0243] The screw may comprise various materials and multiple different configurations including solid or hollow screw designs. A hollow screw provides a distinctive benefit of permitting a heating medium such as superheated steam to pass through the hollow screw without ever touching the raw materials. This may allow for efficient heating using fluids that would be even incompatible with the main reaction chemistry. The flights on the screw may be customized to provide special material flow characteristics from simple agitation to chopping, grinding, and mixing or a combination of all. These flight designs may improve reaction kinetics and product uniformity.

[0244] A horizontal reactor system may comprise additional or alternative internal material handling systems from a screw design for moving material through the reactor.

[0245] The system may use a reactor wall as a material heating source, with the internal screw provides a large surface area that is in contact with the raw material. The screw may be augmented to facilitate heating, cooling and / or otherwise managing temperature within the main reaction vessel. The screw or portions of the screw may beused to directly impart heat to the raw material. As a result, the rate of heat transfer to the material may be expedited.

[0246] The material feedstock may be moved by dumping the material, a rotary valve, or other material handling system.

[0247] The reaction vessel may be substantially horizontal as shown in Fig. 22A, though angled vessels or even vertical vessels may be used as illustrated in other variations described herein.

[0248] Heating the feedstock may be provided in part through heat transfer through a wall of the reaction vessel. Alternatively other heating elements may be integrated into the reaction vessel.

[0249] The gaseous material may comprise steam and / or other gases. The gaseous material is preferably introduced to catalyze the reaction. The gaseous material may be introduced in one or more different points. The gaseous material be introduced along a set of different points. The gaseous material may be introduced consistently at the set of different points. The gaseous material may be introduced in distinct manners at different points (e.g., different gaseous composition, temperature, pressure, ora combination thereof).

[0250] Exhausting the gaseous material may flush introduced gaseous material from the reaction vessel. Exhausting may be performed to gaseous material that has had a chance to catalyze the reaction. The gaseous material may be exhausted with the introduction of gaseous material which may maintain pressure.

[0251] The reacted material may be deposited by dropping the reacted material into the product hopper via a dump, rotary valve, or other suitable type of material handling system. As described in other variations, the reacted material may alternatively be transferred to a subsequent reaction vessel or other system for further processing.

[0252] The system may comprise a plurality of reactors in tandem or parallel. The conditions for processing the reacted material within the subsequent stage reactor vessel may be consistent with the initial reactor vessel. This may be used to approximateprocessing by a longer reaction vessel. The conditions for processing the reacted material within the subsequent stage reactor vessel may alternatively use differing conditions for implementing staged processing.

[0253] As one example, inside an initial first screw reactor unit, the temperature can be very high to help calcine a material very quickly. The partially reacted material may then move into the next screw reactor unit which may be at a much lower temperature and much lower atmospheric turnover rate due to the first screw pre-calcining most of the material. The product formed may then go into a third screw reactor unit which uses a hollow screw design to rapidly cool the material while recovering most of the heat for use elsewhere. This cooled material may then enter an optional fourth screw reactor unit where CO2may be reintroduced to form a carbonated cementitious material. In each separate screw unit, a system for injecting in steam, air, nitrogen, and other gases is used to create a positive pressure flow. An exhaust in each screw may remove the exhaust gases for further use or processing. Between each screw unit, an atmosphere isolating transfer valve may be used to convey the material. These include dump valves or rotary air locks.

[0254] A stationary reaction vessel shell and moving screw may allow fine tune control of the gas input, gas removal, material propagation, kinetics (heat addition or removal with multiple heat zones), multiple gas injection and gas removal points may be added along the length of the system. Each zone may be optimized for the specific atmospheric composition required in that zone. Specific temperatures and gas flow rates may be set in each zone to optimize kinetics.

[0255] In one variation, the reaction vessel may be configured as a vertical gravity reactor that utilizes gravity (at least in part) to facilitate material movement through the reaction vessel. In the gravity reactor no fluidization may be used. Steam or other gases may be used to sufficiently catalyze the reaction. Heating may be provided electrically through the side walls and material may fed into and out of the reactor using atmosphere isolating valves such as rotary airlocks and dump valves. The vertical gravity reactor may control the gas input and output to produce a specific gas gradient along the direction of material travel. The counter current flow is specifically adjusted to ensure that reaction kinetics are optimal as the material travels towards the outfeed.

[0256] The systems and methods described herein function to enable an apparatus for synthesis of cementitious materials and / or other types of materials. The systems and methods describe design and operation of a specialized reactor that may be configured to produce a variety of product types. The production process enabled through the reactor can use a hydrothermal vapor recrystallization process (“HVRP”) or other steam-based process and material production approaches. The systems and methods described herein detail a reactor design and variations that may use a prescribed combination of temperature, steam, in-situ / ex-situ gas management, and material conveyance to facilitate desired chemical reactions. Such systems and methods may be used as a mineralization / carbonation chamber to create carbonated products. These carbonated products may be SCMs.

[0257] The systems and methods in some variations are used to produce cementitious materials, but the system and methods may be used for the production of a variety of types of material products and / or combinations of products. The material products may include, but are not limited to, supplementary pozzolanic materials (SPMs); supplementary cementitious materials (SCMs);hydraulic cements, decarbonized cementitious + pozzolanic materials, any other cementitious material or inorganic oxide; or a combination thereof. The systems and methods of the discussed reactor may also be used to produce a variety of inorganic materials.

[0258] The systems and methods described herein enable a novel chemical reactor that can manage a combination of prescribed temperature profile, pressurized atmosphere, in-situ / ex-situ gas management, and material conveyance into and out of the reactor. The systems and methods described herein may include a variety of different subcomponents and variations, which may be customized and / or employed in differing combinations depending on the application and desired functionality / properties. These subcomponents may be combined into multiple unique configurations to accommodate specific requirements for continuous HVRP processing at large scale production. The some system and method variations may be an industrially sized, low energy consuming, electrified, and highly efficient reactor for large scale production of inorganic materials. The reactor may offer substantially faster reaction kinetics relative to their counterparts that are formed via solid-state reactions (at equivalent temperatures).

[0259] High-temperature processes typically generate nitrogen oxides (NOX) and sulfur oxides (SOX), both of which are harmful pollutants. A lower-temperature process of the systems and methods may result in significantly lower emissions of these gases, contributing to cleaner air and reduced environmental impact. Without the need for a partial melt, the system and method of the new production process may allow for the production of cement types with unique properties, such as lower shrinkage, enhanced durability, or faster setting times. These could open new applications or improve the performance of existing cement products.

[0260] A lower-temperature process of the systems and methods may also lead to more uniform material processing, potentially resulting in cement with more consistent quality and performance characteristics.

[0261] The systems and methods may enable various benefits related to process flexibility and operations. As one such benefit related to process flexibility, the system and method may allow for more decentralized production. Lower temperature and alternate equipment of the systems and methods might make the process more adaptable for smaller-scale, decentralized production facilities. A process that operates at lower temperatures may also be easier to control and optimize, allowing for more precise adjustments to ensure consistent product quality. This may also reduce the likelihood of operational issues such as kiln ring formation or clinker quality variability.

[0262] The system and / or method may enable enhanced gas and atmosphere control and / or optimization. A reactor of the systems and / methods that uses HVRP or other steam-based processing may have one or more gaseous products in the atmosphere. The primary gaseous component may be pressurized, high-temperature steam, with other gaseous elements that are produced as a function of feedstock decomposition, or gases introduced to help facilitate the chemical reactions. Since the primary gas may be comprised of H2O, condensation of this gas can allow for gas separation, allowing for a relatively pure stream of reaction gases to be harnessed.

[0263] As another potential benefit, the systems and methods may provide flexibility in both gas delivery and removal. A reactor of the systems and / methods that useHVRP or other steam-based processing may not have combustion gases present inside the reactor. As such, the reactor has flexibility over reaction atmosphere gas composition by simply modifying the following: gas injection site, injected gas composition, injected gas duration before ejection (e.g., the residence time of the gas inside the reaction zone), and modifying the flow patterns to achieve optimal reaction rates.

[0264] Embodiments of the present invention provide a technology-based solution that overcomes existing problems with the current state of the art in a technical way to satisfy an existing problem for cement manufacturers. Embodiments of the present invention achieve important benefits over the current state of the art, such as low-temperature synthesis of reactive calcium silicates followed by rapid carbonation to produce high-performance, CO2-sequestered SCMs suitable for use in concrete applications. Some of the unconventional steps of embodiments of the present invention include synthesis of carbonated calcium silicate-based materials in a rapid, single-stage or dual-stage configuration.Industrial Applicability:

[0265] The invention is further illustrated by the following non-limiting examples.Example 1

[0266] Quarry-derived raw materials from a cement plant were blended to achieve a Ca / Si molar ratio of 2.0, forming the synthesis feedstock. This mixture was milled to a particle size distribution with d90 = 19 micrometers, d50 = 8 micrometers, and d10 = 2 micrometers. Synthesis was then performed in a rotary kiln at 750 °C for a duration of two hours, with a feed rate of 1 kilogram per hour (“kg / hr”). During synthesis, the gas stream in the reactor comprised 13% CO2and 87% water vapor (by partial pressure). X-ray diffraction (“XRD’’) analysis of the synthesized product revealed the following phase composition: 56% total carbonatable phase, 20% amorphous phase, and 24% total non-carbonatable phase. Subsequently, water was sprayed onto the synthesized powder at a water-to-solid mass ratio of 0.5 to produce a moist powder. This wet material was fed into the carbonation reactor, where it underwent carbonation at 90 °C for 10 minutes. The gasstream in the carbonator had a partial pressure composition of 31% CO2and 69% water vapor. Post-carbonation analysis showed a CO2uptake of 33%.

[0267] The carbonated material was subsequently milled to break down soft agglomerates and achieve a particle size distribution with d90 less than 24 micrometers. Following this, batching and casting of mortar samples were carried out in accordance with ASTM C311. Type IL cement was used for mortar fabrication. Control samples containing 100% Type IL cement were prepared for comparison against test samples in which 20% of the cement was replaced with the carbonated material. Cube specimens were cast and placed in a moist curing room maintained at 23.0 °C ± 2 °C for a period of 20 hours to 24 hours, ensuring protection from dripping water. After this initial curing period, the cubes were demolded and transferred to a saturated limewater bath, where they remained until testing for compressive strength in accordance with ASTM C109. The measured water demand for the mixes was 100% to 112%. The average strength activity index (“SAI”) of the samples at 7 days and 28 days was found to be 88% and 86%, respectively. Bound water content was determined using ASTM C1897-20 - Method B, with the average 7-day bound water content measured at 3.42%.

[0268] The preceding examples can be repeated with similar success by substituting the generically or specifically described reactants and / or operating conditions of this invention for those used in the preceding examples.

[0269] Note that in the specification and claims, “about” or “approximately” means within twenty percent (20%) of the numerical amount cited. The terms, “a”, “an”, “the”, and “said” mean “one or more” unless context explicitly dictates otherwise. The term “and / or” as used herein means that the listed items are present, or used, individually or in combination. In effect, this term means that “at least one of’ or “one or more” of the listed items is present or used.

[0270] Although the invention has been described in detail with particular reference to these embodiments, other embodiments can achieve the same results. Variations and modifications of the present invention will be obvious to those skilled in the art and it is intended to cover in the appended claims all such modifications and equivalents. Theentire disclosures of all references, applications, patents, and publications cited above are hereby incorporated by reference

Claims

CLAIMSWhat is claimed is:

1. A system for producing a silicate material, said system comprising:a first reactor comprising a first spray nozzle and a first airlock;said first reactor configured to receive a superheated steam;said first reactor configured to receive a first process gas;a second reactor comprising a second spray nozzle and a second airlock;said second reactor configured to receive a steam; andsaid second reactor configured to receive a second process gas.

2. The system of claim 1 wherein said first reactor further is disposed at an angle.

3. The system of claim 1 wherein said first reactor comprises a first end cap.

4. The system of claim 1 wherein said first reactor is a hydrothermal vapor recrystallization process reactor.

5. The system of claim 1 further comprising an inlet for introducing and disposing liquid water within said first reactor.

6. The system of claim 1 wherein the first process gas comprises carbon dioxide.

7. The system of claim 1 wherein said second reactor comprises a screw auger.

8. The system of claim 1 wherein said second reactor comprises a second end cap.

9. The system of claim 1 further comprising an inlet for introducing and disposing liquid water within said second reactor.

10. A method for producing a silicate material, the method comprising:heating a feedstock;disposing the feedstock in a reactor;applying steam to the feedstock to yield a calcium silicate material;cooling the calcium silicate material;applying moisture to the calcium silicate material; andcarbonating the calcium silicate material to yield a carbonated silicate material.

11. The method of claim 10 further comprising milling a raw material to form the feedstock12. The method of claim 10 further comprising conveying the feedstock through the reactor.

13. The method of claim 10 further comprising flowing a countercurrent stream of process gas through the reactor relative to the conveyed feedstock.

14. The method of claim 10 further comprising flowing a co-current stream of process gas through the reactor relative to the conveyed feedstock.

15. The method of claim 10, wherein the feedstock comprises a of calcium and silicon bearing material.

16. A calcium silicate material composition comprising: synthetic calcium silicate.

17. The composition of claim 16, wherein the synthetic calcium silicate comprises betadicalcium silicate.

18. The composition of claim 16, wherein the synthetic calcium silicate comprises alpha prime-dicalcium silicate.

19. The composition of claim 16, wherein the synthetic calcium silicate comprises gamma dicalcium silicate.

20. The composition of claim 16 further comprising a pozzolanic amorphous phase.

Images