Method of processing alkaline materials

Abstract

A method for producing a carbonated alkaline material includes sealing an alkaline material in an enclosure, the alkaline material having a first particle size characteristic and a first specific surface area, and curing the alkaline material within the enclosure in the presence of carbon dioxide. During the curing of the alkaline material and within the enclosure, the alkaline material is ground to produce the carbonated alkaline material having a second particle size characteristic that is different from the first particle size characteristic and / or having a second specific surface area that is different from the first specific surface area.

Description

METHOD OF PROCESSING ALKALINE MATERIALSCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority on United States patent application No. 63 / 726,300 filed on November 28, 2024, the entire content of which is incorporated herein.TECHNICAL FIELD

[0002] This disclosure relates generally to alkaline materials and methods of processing same, and more particularly to carbonated alkaline materials that may, for example, be used in concrete products.BACKGROUND

[0003] In manufacturing traditional concrete products, a dry mixture, which may include a cement and an aggregate, is mixed with water. The mixture subsequently undergoes a curing step, in order to obtain the final concrete product. It may be labour intensive and polluting to extract certain cement-based binders, such as Ordinary Portland Cement. Moreover, some parameters may affect how the concrete products is manufactured. There exists a desire to minimize environmental impacts of concrete products manufacturing and, at the same time, to optimize manufacturing parameters to obtain concrete products meeting desired performance metrics.SUMMARY

[0004] There is accordingly provided, in one aspect of the present disclosure, a method of producing a carbonated alkaline material, comprising: sealing an alkaline material in an enclosure, the alkaline material having a first particle size characteristic and a first specific surface area; curing the alkaline material within the enclosure in the presence of carbon dioxide; and during the curing of the alkaline material and within the enclosure, grinding the alkaline material to produce the carbonated alkaline material, the carbonated alkaline material having a second particle size characteristic that is different from the first particle size characteristic and / or having a second specific surface area that is different from the first specific surface area.

[0005] The method as defined above and as described herein also includes, in certain embodiments, the following features and / or steps, in whole or in part, and in any combination.

[0006] In certain embodiments, the first and second particle size characteristic include an average particle diameter.

[0007] In certain embodiments, the average particle diameter of the carbonated alkaline material is at least 1 % less than that of the alkaline material.

[0008] In certain embodiments, the first and second particle size characteristic is defined by a D50 of particles.

[0009] In certain embodiments, the D50 of the alkaline material is at least 1 % different from the D50 of the carbonated alkaline material.

[0010] In certain embodiments, the second specific surface area of the carbonated alkaline material is at least 1 % different from the first specific surface area of the alkaline material.

[0011] In certain embodiments, the method includes providing carbon dioxide within the enclosure at a concentration of at least 0.5% by volume and at a gauge pressure of at least 0.01 psig.

[0012] In certain embodiments, the grinding is performed intermittently and the curing in the presence of carbon dioxide is performed continuously.

[0013] In certain embodiments, the alkaline material includes steel slag, wollastonite, recycled concrete, cements, stainless steel slag, iron slag, fly ash, calcium hydroxide, calcium oxide, periclase Portland cement clinker, olivine, pyroxenes, plagioclase, feldspars, and / or calcium silicate materials.

[0014] In certain embodiments, the alkaline material comprises one or more of a silicate based material including CasSiOs, CaSiCh, Ca2SiC>4, Mg2SiC>4, CaMg(SiC>3)2, and CaAl2Si2Os.

[0015] In certain embodiments, the alkaline material is steel slag, the steel slag comprising at least one of EAF, BOF, and ladle steel slag.

[0016] In certain embodiments, the method further includes mixing the carbonated alkaline material with an aggregate and water to produce one of: a ready-mix concrete; a dry-cast concrete; and a precast concrete.

[0017] In certain embodiments, the method further includes mixing the carbonated alkaline material with a binder and / or an additive.

[0018] In accordance with another aspect, there is also provided a method of processing an alkaline material having a first particle size characteristic, the method comprising grinding the alkaline material while concurrently curing the alkaline material using carbon dioxide to produce, once the curing is complete, a carbonated alkaline material having a second particle size characteristic that is different from the first particle size characteristic.

[0019] The method as defined above and as described herein also includes, in certain embodiments, any of the above-noted or following features and / or steps, in whole or in part, and in any combination.

[0020] In certain embodiments, the second particle size characteristic includes a smaller particle size and / or a larger specific surface area relative to the first particle size characteristic of the alkaline material.

[0021] In accordance with another aspect, there is also provided a method of producing a carbonated alkaline material comprising grinding an alkaline material and curing the alkaline material using carbon dioxide, the grinding and the curing occurring simultaneously within a sealed enclosure.

[0022] The method as defined above and as described herein also includes, in certain embodiments, any of the above-noted features and / or steps, in whole or in part, and in any combination.

[0023] In accordance with another aspect, there is also provided a system for producing a carbonated alkaline material, comprising an enclosure defining a curing chamber and configured for sealing an alkaline material therein, a source of carbon dioxide in communication with the enclosure to feed the carbon dioxide into the curing chamber and cure the alkaline material, and a grinder operable to grind the alkaline material while exposed to the carbon dioxide to produce the carbonated alkaline material, the carbonated alkaline material having a smaller particle size and / or a larger specific surface area relative to the alkaline material.

[0024] In certain embodiments, the grinder itself defines the enclosure, the curing chamber being formed within the grinder.

[0025] In certain embodiments, the grinder is located within the enclosure.

[0026] In accordance with another aspect, there is also provided a carbonated alkaline material produced by curing an alkaline material in the presence of carbon dioxide, the carbonated alkaline material having a smaller particle size and / or a larger specific surface area relative to the alkaline material.BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Reference is now made to the accompanying figures in which:

[0028] Fig. 1A is a schematic view of a system used for curing and grinding an alkaline material according to a first exemplary embodiment of the present disclosure;

[0029] Fig. 1 B is a schematic view of a system used for curing and grinding an alkaline material according to a second exemplary embodiment of the present disclosure;

[0030] Fig. 2 is a flowchart illustrating steps of a method of manufacturing a concrete product in accordance with one embodiment;

[0031] Fig. 3 is a schematic representation of a controller in accordance with one embodiment;

[0032] Fig. 4 is a graph showing the CO2 uptake as a result of cyclic grinding and carbonation process in steel slag;

[0033] Fig. 5A is another schematic view ofthe system of Fig. 1A, used for concurrently curing and grinding an alkaline material such as steel slags; and

[0034] Fig. 5B is another schematic view ofthe system of Fig. 1 B, used for concurrently curing and grinding an alkaline material such as steel slags.DETAILED DESCRIPTION

[0035] Various representative embodiments of the described technology will be described more fully hereinafter with reference to the accompanying drawings, in which representative embodiments are shown. The present technology concept may, however, be embodied in many different forms and should not be construed as limited to the representative embodiments set forth herein. Rather, these representative embodiments are provided so that the disclosure willbe thorough and complete, and will fully convey the scope of the present technology to those skilled in the art. In the drawings, the sizes and relative sizes of layers and regions may be exaggerated for clarity. Like numerals refer to like elements throughout.

[0036] It will be understood that, although the terms first, second, third, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used to distinguish one element from another. Thus, a first element discussed below could be termed a second element without departing from the teachings of the present technology. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0037] The terminology used herein is only intended to describe particular representative embodiments and is not intended to be limiting of the present technology. As used herein, the singular forms "a," "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.Introduction

[0038] There remains growing interest worldwide to reduce the environmental footprint of precast concrete and alkaline materials including waste materials. Carbonation curing technology is among the most promising solutions. During carbonation curing, alkaline materials harden mainly through the so-called carbonation reaction which happens between carbon dioxide and the oxides, and / or hydroxide of calcium and / or magnesium present in the alkaline materials, with the existence of water. In the example of concrete, under appropriate raw material selection, mix design and process control, carbonated precast concrete may be as strong and durable as traditional precast concrete, and suitable for a variety of applications.

[0039] Manufacturing precast concrete or other material products with carbonation curing technology may address concerns over climate change. Under appropriate processing condition, freshly cast concrete products may achieve rapid hardening when being exposed in CCh-rich environment. This may help to mitigate the CO2 emissions associated with the construction industry. This can be similarly achieved with alkaline materials more generally (i.e. not necessarily concrete). Other advantages of carbonated precast concrete may include the improvement ofproductivity through rapid hardening, the reduction of production cost through the replacement of ordinary Portland cement with environmental-friendly and less expensive binders such as steel slag, and so on.

[0040] Mineral carbonation is based on the reaction of CO2 with metal oxide bearing materials to form insoluble carbonates, with calcium and magnesium being the most attractive metals. Mineral carbonation occurs when a high concentration CO2 is brought into contact with metal oxide bearing materials with the purpose of fixing the CO2 as carbonates.

[0041] Due to initiatives regarding carbon emissions, mineral carbonation of CO2 into cementbased materials has gained attention in recent years. The cement industry is a primary producer of carbon dioxide (CO2), which is recognized as a major greenhouse gas. Thus, disadvantageously, large amounts of CO2 are produced by the chemical reactions occurring in the manufacture of cement. Mineral silicate containing metal oxide bearing residues, such as steel slag, can be carbonated and may be used as a much-reduced CC>2-emitting alternative. In addition to binder activation, carbonation’s valorizing potential can also be exploited to recycle suitable industrial wastes into raw building materials. The perpetual fixation of carbon dioxide in building products conduces a more sustainable stance for the concrete industry as it fulfills mandates for lower carbon footprint.

[0042] In the context of the present disclosure, the expressions “cement” and “binder” have different meanings. A binder is a material that, when mixed with water will cause hardening of the mixture to obtain a concrete product. A cement is a specific type of binder. For instance, binders include Ordinary Portland Cement, steel slag, stainless steel slag, and so on. Cements include Ordinary Portland Cement, other kinds of cement. Slags are binders, but they are not considered cements. Binders may include hydraulic binders, such as cement, and non-hydraulic binders, such as slags (e.g., steel slags). A binder is referred to as “hydraulic” when reaction with water causes the hardening of the concrete product. A binder is referred to as “non-hydraulic” when another ingredient is responsible for the hardening of the concrete product. In the case of steel slag, this other ingredient is carbon dioxide.

[0043] U.S. Pat. No. 10,112,871 and U.S. Pat. No. 11 ,358,902, the entire contents of which are incorporated herein by reference in their entirety, describe a method of producing a wet-cast slag-based concrete product particularly where the wet-cast slag-based concrete product ispartially or completely set inside a mold, pre-conditioned outside of the mold and then subjected to mineral carbonation with exposure to CO2 in a carbonation enclosure.

[0044] There remains growing interest worldwide to reduce the environmental footprint of precast concrete. Conversion of carbon dioxide into solid calcium carbonate, via carbonation, is among the most promising solutions. During carbonation, precast concrete hardens mainly through a so-called carbonation reaction which happens between carbon dioxide and the oxides, and / or hydroxide of calcium and / or magnesium, with the existence of water. Under appropriate raw material selection, mix design and process control, carbonated precast concrete may be as strong and durable as traditional precast concrete, and suitable for a variety of applications.

[0045] Manufacturing precast concrete with carbonation technology or mineralization may address concerns over climate change. Under appropriate processing condition, freshly cast concrete products may achieve rapid hardening when being exposed in CC>2-rich environment. This CO2 conversion may help to mitigate the CO2 emissions associated with the construction industry. Other advantages of carbonated precast concrete may include the improvement of productivity through rapid hardening, the reduction of production cost through the replacement of ordinary Portland cement with environmental-friendly and less expensive binders such as steel slag.

[0046] In accordance with a first aspect of the present technology, there is provided a system and method for the conversion of carbon dioxide (CO2) into a solid calcium carbonate for use in CO2 containing mineral products, the system comprising at least one enclosure which is a combined grinding / crushing and curing enclosure; at least one gas handling system; at least one control system; at least one source of carbon dioxide; and at least one alkaline material that is bearing metal-oxides.Curing and Grinding

[0047] The present disclosure provides systems and processes for concurrently curing and grinding an alkaline material in orderto modify the size ofthe alkaline material and / or their specific surface area during curing. This allows for improved carbon dioxide absorption during curing because of the exposure of uncured surfaces and the increase in surface area in the alkaline material which increases the reaction surface. The concurrent curing and grinding can be performed in a grinder that provides a closed environment for maintaining carbon dioxide toperform the curing. Alternatively, the grinder can be placed inside of an enclosure which provides the enclosed environment for carbon dioxide curing.

[0048] Referring now to FIG. 1A, an exemplary system for grinding and curing an alkaline material is shown at 10 where the grinder itself provides the carbon dioxide environment for curing. In such an embodiment, the grinder 14 should have at least one gas inlet and at least one gas outlet. FIG. 5A also alternately depicts the system of FIG. 1 A, wherein the grinder / pulveriser acts as a CO2 curing chamber for producing CO2 enhanced steel slag. The CO2 enhanced steel slag can then be used as a constituent material for a number of possible uses, as shown on the right side of FIG. 5A.

[0049] Alternatively, as illustrated in the embodiment of Fig. 1 B, the grinder 14 is located inside a sealed enclosure 11 , for example a curing chamber. FIG. 5B also alternately depicts the system of FIG. 1 B, wherein the grinder / pulveriser acts is located within a sealed curing chamber that encloses a CO2 enriched environment, for producing CO2 enhanced steel slag. The CO2 enhanced steel slag can then be used as a constituent material for a number of possible uses, as shown on the right side of FIG. 5B.

[0050] The system 10 includes a source of carbon dioxide 13, which may be a reservoir or tank, that is fluidly connected to a grinder 14 via a line 12. In optional embodiments shown, the system 10 may further include a heater for heating the carbon dioxide as it flows from the source of carbon dioxide 13 to the grinder 14. The system 10 may include a valve that may be selectively open or closed to allow or restrict the flow of carbon dioxide toward the grinder 14. The valve may be controlled to adjust its position to control a mass flow rate of the gas into the enclosure 11 .

[0051] In the embodiment of Fig. 1A, the grinder 14 itself defines an inner space or chamber 14a, that is sized to accept the alkaline materials to be carbonated. In the embodiment shown, the grinder 14 includes top bottom and side walls interconnected to one another in an airtight manner, to thereby itself form an enclosure within which the curing chamber is defined. In the context of the present disclosure, “airtight” implies that there is little to no leakage of gas through the grinder 14 at a pressure differential the grinder 14 is subjected to. The pressure differential corresponds to a difference between the pressure inside the grinder 14 and an ambient pressure outside the grinder 14. The grinder 14 may be structurally designed to withstand a pressure differential created by a greater pressure of the carbon dioxide inside the grinder 14 than an atmospheric pressure outside the grinder 14. A blower may be located in the chamber 14a of thegrinder 14 and is operable to generate an airflow F and to better distribute the carbon dioxide in the chamber 14a.

[0052] The system 10 performs the CO2 curing of the alkaline materials while the alkaline materials are being crushed, ground or otherwise reduced in size such, within the grinder 14, as to create smaller particles, for example by using grinding / crushing means 22. When a CO2- reactive particle is exposed to CO2 and moisture, carbonation reaction starts on the exposed surface of the particle. As a result, a passivating layer of carbonated products covers the exposed surface of the particles preventing further leaching of ions from the materials and also impeding the penetration of CO2 into inner layers of the particle. At this point, the carbonation reaction starts to slow down only due the presence of this passivating layer and not due to absence of reactive materials. Breaking the particles using grinding exposes un-carbonated “fresh” surfaces of the alkaline materials for carbonation. Furthermore, the grinding likely acts as a way to peel away some of the passivating layer. Accordingly, this can lead to a significant increase in carbonation reaction within the same quantity of reactive alkaline materials which also means increased carbon uptake and CO2 sequestration forthat same quantity. This action of breaking / crushing the particles is performed in the presence of CO2 which is provided continuously or intermittently. Although the carbon dioxide is provided intermittently, the continuous presence of carbon dioxide can maintain the curation as a continuous step. It is also contemplated to perform the crushing intermittently. In some embodiments, the grinding is performed continuously whereas the crushing is intermittent. The combined grinding and curing allows the production of value-added low CO2 or carbon negative materials that can be used as aggregates, filler, binder, or supplementing cementitious materials in any type of concrete. An advantage of the present method and system is that it can carbonate any type of steel slag including the ones that would not qualify as a binder for making carbonated steel slag concrete. Because the present system contemplates alkaline materials in general, the resulting carbonated alkaline materials are not limited to concrete products but can also be materials useful in industries such as road construction or plastic, polymer, agriculture and paint industry, and the like.

[0053] Accordingly, the present process involves, while the alkaline material is curing in the enclosure (curing chamber), reducing a particle size of the alkaline material (such as by grinding, for example) within the enclosure. It should be noted that the carbonation results in an increase in size whereas the grinding leads to a size reduction. Accordingly, in some embodiments, because of the carbonation, and despite the grinding, the size of the particles may remain constant or even increase. In such embodiments however, the grinding still has a discernibleeffect and causes an increase in the specific surface area of the particles being carbonated. Accordingly, the discernible effect can be define herein as providing a different particle size characteristic and / or a different specific surface area where the term “different” is an increase or a decrease of at least 1%, at least 3%, at least 5%, or at least 10%. Once cured, therefore, the carbonated alkaline material may have a second (smaller) particle size and / or may have an increased specific surface area. Stated differently, the particle size characteristic of the carbonated alkaline material (i.e., after curing) can be smaller in some embodiments than a particle size characteristic of the alkaline material before curing. Alternatively or in addition, in some embodiments, the specific surface area of the alkaline material particles will be smaller than the specific surface area of the carbonated alkaline material. The present process can thus be referred to as a Concurrently Grinding and Carbonation (CGC) process. In one example where the alkaline materials are steel slag, the produced material at the end of the CGC process is CO2 Enhanced Steel Slag (CESS).

[0054] The term “particle size characteristic” as used herein is understood to include, in one embodiment, the average diameter of the particles (i.e., the average particle size). In another embodiment, the “particle size characteristic” of the material may be defined as the D50 of particles.

[0055] The term “specific surface area” is a commonly used parameter calculated by dividing the total surface area by the mass of the sample (m2 / g). In some embodiments, the specific surface area is increased or decreased by at least 1 %, at least 5%, at least 10% or at least 20%.

[0056] The simultaneous CO2 curing and grinding of the alkaline materials takes place inside an enclosure 11 such as those illustrated in FIGs. 1A-1 B. In some embodiments, the grinder 14 is separate from the CO2 reactor / chamber / scrubber / enclosure 11 . The enclosure 11 includes the mechanical / physical manipulator 14 that can perform the grinding. This manipulator 14 can be in the form of a grinder, mill, pulveriser, crusher, polisher, tumbler, or any other equipment that can break the particles.

[0057] The grinder 14 can be a jet mill, ball mill, vertical roller mill, rod mill, pebble mill, high- pressure grinding rolls (HPGR), ring and puck mill, stirred media mill, autogenous mill, semi- autogenous mill, Hammer Mill, Disc Mill, Colloid Mill, Pin Mill, Centrifugal Mill, Attritor Mill, Vibratory Mill, Planetary Ball Mill, Cage Mill, Fluidized Bed Jet Mill, Impact Mill, End Mill, Roller Mill, Cutting Mill, Knife Mill, Cryogenic Mill, Tower Mill, Cone Mill, Disk Attrition Mill, Turbo Mill,Ultrafine Mill, Air Classifier Mill, Bead Mill, Raymond Mill, Chopper Mill, Conical Screen Mill (Comil) or a grinder based on any other known technology. The grinder can have the capability of adjusting its rate and intensity of the grinding action. In one example where a ball mill grinder is used to break the reactive particles, the rates per minute (RPM), number and size of the grinding balls (grinding medium), mass / volume of the material to grinding medium, and grinding energy of the ball mill grinder can be adjusted. In the embodiment shown in Fig. 1A, the grinder 14 is sealed and airtight. In other words, the grinder 14 and is the enclosed (i.e. a one piece equipment).

[0058] Alternatively, as illustrated in the embodiment of Fig. 1 B, the grinder 14 is located inside an enclosure 11 , for example a curing chamber, that is air-tight. The gas conditions such as pressure, CO2 concentration, relative humidity (RH), temperature, and airflow inside the enclosure can be monitored (using sensors) and controlled.

[0059] In some embodiments, the grinder 14 is a jet mill and has at least one port for injecting water. Liquid water can be injected into the grinder 14 using at least one water nozzle, water sprayer / atomizer, and / or water mister. Alternatively, steam can be injected into the grinder 14 through a suitable inlet. Additionally, the grinder can include a sampling port for gas and solids.

[0060] It should be noted that regardless of whether the grinder is incorporated as part of one piece equipment as illustrated in Fig. 1A or whether the grinder 14 is positioned inside the enclosure 11 which provides air-tight sealing, the grinder / enclosure are optionally pressurized, i.e. they can withstand the pressure from the gas inside.

[0061] The grinder may optionally include a separation system (e.g. air separator, static separator, dynamic separator, magnetic separator and the like). The separation system allows the grinder to reach to the desired particle size characteristic for the particles. The surface area of the particles can also be adjusted. In one example, the grinding action can be stopped once the particle size characteristic reaches a certain level. In another example, the curing process can be stopped once the carbon content of the material reaches the desired level.

[0062] The action of breaking the particles of alkaline materials (crushing / grinding) can take place continuously or periodically. In one embodiment, the grinder runs continuously during the curing process in the presence of a CCh-rich gas. In another embodiment, the grinder starts and stops periodically during the curing process in the presence of a CCh-rich gas. In either case, concurrent grinding and curing still occurs. In one example, a ball mill grinder can rotate continuously or periodically during the curing process. Also, the grinding system can be acontinuous or batch process system. In one example, the input material can be steel slag (electric arc furnace (EAF), basic oxygen steelmaking (BOS or BOF), ladle etc.), stainless steel slag or Portland cement clinker.

[0063] A humidification / moisturization and dehumidification system can optionally be implemented and applied periodically. The rate and duration of dehumidification and humidification can be constant or varied throughout the curing process. The duration of dehumidification and humidification can be adjusted based on the feedback from the enclosure or grinder. In one example, moisture is introduced into the grinder every 30 minutes and the moisture is removed by dehumidification during the 30-minute intervals.

[0064] In order to make a CCh-rich environment in the enclosure, CO2 can be introduced in the system in the form of gas or dry ice. The CC>2-rich gas can be flue gas, recycled CO2 from other processes, pure CO2, or a combination of all. Carbon dioxide gas, which may have a purity ranging from 5% to 99.9% may be used for the carbonation in the present process. The pressure of carbon dioxide gas may be adjusted to from 0 MPa to 0.827 MPa (0-120 psi) during the carbonation process which may last from 5 minutes up to 120 hours at around 20-100°C temperature and 20-90% relative humidity. Carbonation may be carried out in a sealed enclosure with CO2 introduced either as a steady gas or as a continuously-circulated gas. In the present embodiment, the pressure of the gas containing carbon dioxide is at most about 15 PSI, preferably from about 2 PSI to about 7 PSI. The carbon dioxide gas introduced to cure the alkaline materials is for example at 5%, preferably 10%, preferably 20%, preferably 30%, preferably 40%, preferably 50%, preferably 60%, preferably 70%, preferably 80%, preferably 90%, or preferably 99.5% purity. The gauge pressure of the gas will gradually increase to a range of 0.1 psi and optionally to 100 psi.

[0065] In some embodiments, the curing of the alkaline materials includes exposing the formed intermediate to the gas containing carbon dioxide at a gauge pressure ranging from 0 psi to 120 psi. In some embodiments, the curing of the alkaline materials includes curing the alkaline materials for from 5 minutes to 120 hours. In some embodiments, the curing of the alkaline materials includes curing the conditioned intermediate at a temperature ranging from 20°C to 80°C. In some embodiments, the curing of the conditioned intermediate includes curing the alkaline materials at a relative humidity ranging from 30% to 90%.

[0066] The term “alkaline material” as used herein refers to materials that have pH of 7 and higher. An alkaline material has a basic property. The alkaline materials / basic materials include or can be part of Portland cement clinker, lime, calcium hydroxide, calcium oxide, cements, serpentine, steel slags, iron slags, stainless steel slags, fly ash, silica fume, metakaolin, wollastonite, calcium-silicate materials, recycled concrete, calcium silicate hydroxide, biochar, olivine, pyroxenes, plagioclase, and feldspars. More generally, Wollastonite, Tremolite, Diopside, Augite, Enstatite, Scapolite, Larnite, Anorthite, Spodumene, Serpentine, Cement, Limestone, Quicklime, Slaked Lime, Hydrated Lime, Calcium Silicate Board, Calcium Silicate Insulation, Calcium Aluminate Cements, Dolomite, Bentonite, Natural Pozzolans, Fly Ash, Albite, Hornblende, Olivine, Nepheline, Mica, Calcium Silicate Hydrate, Portlandite, Silicate Slag, Reactive Magnesium Silicate Minerals, or Calcium-rich Biochar. The alkaline materials for example include Ca(OH)2, CasSiOs, Ca2SiO4, Mg2SiO4, CaMg(SiO3)2, and CaAl2Si2Os. It should be understood that the alkaline materials can be part of a mixture of materials and such mixture can be provided in the presence process as long as it contains alkaline materials. The alkaline materials are for example calcium containing materials or silicate containing materials.

[0067] The alkaline materials can be optionally pre-processed prior to being fed into the enclosure. As shown in Figs. 1A-1 B, a reservoir of alkaline materials 15 can either be directly connected to the enclosure 11 or can pass through one or more pre-treatment apparatus 17. The pre-processing by the pre-treatment apparatus 17 can include partial or complete drying, moisturizing, crushing, pre-grinding, blending, heating, physical or chemical separation, chemical treatment, or a combination of all. In one example, the alkaline materials are raw steel slags which go through a process to separate metallic and non-metallic iron from it. In another example, steel slag is partially or fully dried before being fed into the grinder 14. In another example, at least two types of steel slag are crushed and blended together before being fed into the grinder 14.

[0068] Generally, steel slag that is acquired from steel plants has higher than optimum moisture content forthe common grinding techniques. Therefore, a drying step before the grinding process is almost always necessary which involves additional cost and energy consumption. This step is minimized or completely avoided in the case of the proposed invention, i.e. CGC process.

[0069] The carbonated alkaline material obtained from the present process has a low CO2 footprint or can potentially be carbon negative. Depending on the process, it can be in the form of fine powder or small to large particles. At the end of the process, the enhanced material can be sieved and classified based on its size, shape, texture, and density. Each size / classification canbe used for different applications in different industries. An example of the material can be steel slag which becomes CO2 Enhanced Steel Slag (CESS) through the method described herein. Specifically for CESS, is useful in the following applications: as raw material in Portland cement and steel industry; as raw material in asphalt production; as aggregate in concrete production; as aggregate in road construction; as binder / filler in precast concrete products to partially or fully replace cementitious materials for both hydration and / or CO2 curing technologies; as binder / filler in ready-mix concrete products to partially or fully replace cementitious materials for both hydration and / or CO2 curing technologies; as Supplementary Cementitious Materials (SCM) in precast and ready-mix concrete for both hydration and / or CO2 curing technologies; as soil stabilizer in agriculture; or as materials in plastic, polymer, and paint industry.

[0070] In one example, the addition of fine CESS in concrete can decrease the permeability of ready-mix concrete by up to 10% (e.g. 8-10%) and increase its compressive strength by up to 10%. Lower permeability improves the durability of the concrete. In another example, up to 10% (e.g. 8-10%) replacement of Portland cement in ready-mix concrete with CESS resulted in better workability of the mix without compromising the performance. In another example, up to 2% (e.g. 1 -2%) addition of fine CESS to Portland cement concrete can act as a hydration accelerator, resulting in 15% earlier peak of hydration and 12% higher peak in heat of hydration. Fine CESS were blended with silica rich materials and heated in a furnace up to 600°C as a pre-treatment The treated CESS material was used as a binder to completely replace Portland cement in readymix concrete and presented uncompromised performance. In another example, the heat treatment temperature is 1200°C. In one example, up to 30% of fine aggregates are replaced with the CO2 enhanced steel slag (partial replacement). In another example up to 60% (e.g. 30-60%) of coarse aggregates are replaced with the CO2 enhanced steel slag as binder,

[0071] In one embodiment CESS is used as supplementary cementitious materials to produce ready-mix concrete, binder for concrete, pre-cast concrete or dry-cast concrete. In the case of ready-mix concrete, CESS is used in the ready-mix concrete where cement is the main binder. In another example, CESS is used as supplementary cementitious materials to produce dry cast or wet cast concrete products.

[0072] In another example CESS partially replaced steel slag in production of dry cast concrete products. In this specific example, up to 80% of steel slag is replaced with CESS in production of concrete pavers, retaining walls, concrete masonry, unites and slabs. Theseconcrete products are subjected to the CO2 curing and / or hydration process. In another example, CESS is used as carbonatable binder in production of precast concrete products

[0073] In one embodiment, CESS is used as filler in production of ready-mix concrete.

[0074] In the case of periodically or intermittently grinding in the present process, the grinding process stops while the CO2 curing / carbonation reaction is continuously ongoing. The time interval between every two grinding periods can be a fixed value or varied. The grinding duration in each cycle can be also fixed or varied. The grinding duration and time interval between every two grinding periods can be determined based on sensors’ feedback (e.g. temperature and RH) and physical and chemical properties of the material (e.g. particle size characteristic and pH). The CO2 concentration, temperature, RH, CO2 pressure, and airflow in each cycle can be varied and different. In one example, the CO2 concentrations at the first cycles can be lower than the CO2 concentration at the latest cycles.

[0075] The gas pressure and CO2 concentration inside the enclosure can be monitored and controlled. Higher or lower CO2 partial pressure can result in faster or slower rate of carbonation reaction respectively. In one example, the gas pressure inside the enclosure is increased until the rate of heat generation, which is an indication of carbonation reaction, has reached the desired level. The pressure inside the enclosure can be optionally ambient pressure (zero-gauge pressure).

[0076] Temperature, relative humidity, and airflow in the enclosure can be monitored and controlled. These factors can control the rate of moisture removal from the material. The carbonation reaction and CO2 penetration into the alkaline materials are directly affected by the moisture content. As the moisture content of the material is lowered, pores become more easily accessible to CO2, and also the concentration of ions in the pore solution is increased. This will lead to precipitation of carbonated products in the pores and on the surface of the particles. Moreover, the kinetics of carbonation reaction are also directly affected by temperature. Therefore, by controlling temperature, relative humidity, and airflow in the enclosure, rate of carbonation reaction can be controlled.

[0077] In addition to pressure, CO2 concentration, relative humidity, temperature, and airflow the enclosure may have capabilities to measure and monitor the following items. The measured values can be communicated to a computer controller for automatic controlling of the process:Mass of CO2 injected into the enclosure through scales or gas flowmeters• Rate of heat generation• Rate of temperature variation• Rate of water removal through dehumidification• Rate of water injection into the enclosure in liquid or gas form• Grinding energy consumption• Sound frequency and intensity during the action of grinding• Physical and chemical properties of the material inside the enclosure such as its bulk density, particle size characteristic using laser diffraction methods, Dynamic Light Scattering methods (DLS), or sieve analysis, specific gravity, surface area using Blaine test, hardness (e.g. Mohr’s method), Mercury Intrusion Porosimetry (MIP), pH or pH variation, carbon content using Thermogravimetry (TG) or Cabon / Sulfur (OS) analysis, X-Ray Diffraction (XRD) analysis, X-Ray Fluorescence (XRF) analysis, Differential Scanning Calorimetry (DSC), titration-gravimetric analysis, Scanning Electron Microscopy (SEM), and zeta potential. These characteristics of the material can be measured inside the enclosure where possible. Alternatively, they can be measured through a sampling port periodically as needed.

[0078] The particle size characteristic of the alkaline materials can be characterized by different metrics such as the following parameters which can be measured by any suitable method as identified above. In some embodiments, the particle size characteristic is characterized by the average diameter of the particles of the alkaline material. Since grinding occurs during the curing, the average diameter of the particles is reduced during this step. For example, the average diameter can be reduce by 10% or more, 20% or more, 30% or more, or 50 % more. In some embodiments, the particle size characeristic is characterized based on the D50 of the material particles. In such embodiments, during the concurrent grinding and curing, the D50 can be reduced by 10% or more, 20 % or more, 30 % or more, or 50 % or more. In some embodiments, the particle size characteristic is characterized based on the D90 of the material particles. In such embodiments, during the concurrent grinding and curing, the D90 can be reduced by 10% or more, 20 % or more, 30 % or more, or 50 % or more. The difference in size referred to hereinrefers to an initial size of the alkaline material compared to the carbonated alkaline material obtained by the concurrent grinding and curing. In certain cases the particles are not spherical or spherical-like in terms of geometries, in such cases, the diameter can be considered to be the greatest the distance between two opposite surfaces of the particle. Furthermore, as explained above, the change in characteristic of the particles can be identified as a change in specific surface area rather than particle size. The specific surface area can be measured by the Langmuir isotherm methods or Brunauer-Emmett-Teller (BET) analysis.

[0079] Accordingly, in some embodiments, the enclosure is capable of measuring the rate and amount of CO2 injected into the enclosure. Combined with pressure and CO2 concentration values, the mass of injected CO2 can be an indication of how the carbonation reaction progresses. This can be used as a decision-making factor to optimize the process. Additionally, machine learning and artificial intelligent tools can be implemented to optimize the process. In one example, the grinding action is stopped while CO2 is being injected into the enclosure; once the amount of CO2 reaches the desired level, the grinding action is started.

[0080] The carbonation reaction is an exothermic reaction. The enclosure is capable of measuring the heat generation and temperature of the material. As the surface of the alkaline material particles gets covered with the passivating layer of carbonated materials, the carbonation reaction and consequently the heat generation and temperature increase are slowed down. At this point, by starting the grinding action, new reactive surfaces on the particles can be exposed which can promote the carbonation reaction further.

[0081] The dehumidification system can measure the rate of water removal. The rate of water removal can also be indicative of the advancement of carbonation reaction which can be used to optimize the process.

[0082] In some embodiments, the enclosure is capable of injecting water into the system. The present process may require cycles of wetting and drying of the material, and this capability may be required along with the dehumidification system.

[0083] As the particles of the material are broken down into smaller particles, and the action of grinding advances, the energy required to grind the material may be reduced. This can be seen through monitoring the grinding energy consumption. In one example, the grinding action is stopped when the grinding energy falls below the desired level of energy consumption.

[0084] Breaking the particles is a physical action that generates sound waves. The characteristics of the sound generated during the grinding action can be an indication of advancement of grinding. In one example, the grinding action can be stopped once the sound frequency and / or intensity reach a predetermined level.

[0085] The enclosure, in some embodiments, has the capability of monitoring the pH of the material. The carbonation reaction is generally associated with a reduction in pH. In one example, once the pH of the material is dropped below the desired level, it can be used as an indication of a slow down in carbonation reaction, and consequently, the grinding action can be started. In another example, a sample is manually taken from the materials in the grinder and its pH value is measured.

[0086] The monitored values can be communicated to a computer. The gas conditions can be controlled manually or automatically using the computer controller in order to optimize the process. The pressure, RH, airflow, temperature, and other relevant parameters are controlled and adjusted with the known technologies.

[0087] Accordingly, the system 10 may further include one or more sensors 18 to measure any of the above mentioned parameters, for example the sensor 18 can be a temperature sensor and a humidity sensor. The temperature sensor and humidity sensor 18 are operatively connected to the chamber 11 a and are operable to generate one or more signals indicative of a temperature and a humidity level inside the enclosure 1 1 . A scale or balance may support the enclosure 1 1 and is used to measure a weight variation of the alkaline materials during the process. The balance may send a signal indicative of a weight of the enclosure 11 containing the alkali materials and carbonated alkali materials. More specifically, the level of carbonation can indirectly be measured by measuring the weight variation and may be used to determine whether the carbonation process is completed.

[0088] The sensors 18 may further include a gas flow meter, a water flow meter, a carbon dioxide sensor to determine a concentration of CO2 in the curing chamber 11 a, an oxygen sensor to determine a concentration of oxygen in the curing chamber 11 a, a pressure sensorto determine a pressure inside the curing chamber 1 1 a, an ultrasonic pulse velocity (UPV), a vibration sensor, accelerometers, strain gauges, Linear Variable Differential Transformer (LVDT) sensors, camera, depth sensor, optical sensor, image sensor, image capturing device or the like. These sensors may be used to assess the completion of the curing process, (e.g., image processing). More detailabout this feature are presented in PCT / CA2024 / 051084, the entire contents of which are incorporated herein by reference in their entirety.

[0089] In the embodiment shown, the system 10 includes a controller 20 that may be operatively connected or coupled to the sensors 18, to the balance, to the heater, to the blower, and to the valve. The controller 20 may therefore independently control the injection of carbon dioxide through the valve and the actuation of the blower. In the embodiment shown, the controller 20 includes a computing device 300 such as the one shown and described below with reference to Fig. 3. The controller 20 may act as a data logger to save temperatures, weights, pressures, etc. data points during the conditioning and curing process. The controller 20 is operable to receive data from the sensors 18 and from the balance; and to control operating parameters of the heater, the valve, and the blower. These operating parameters may include, for instance, a temperature of the heater to achieve a desired temperature of the gas injected in the enclosure 1 1 , whether the valve should be opened, closed, or at an intermediate position to control a flow of carbon dioxide through the valve, a rotational speed of the blower, and so on. More detail about these aspects are presented herein below with reference to Fig. 3.

[0090] To assess the percentage of CO2 converted during curing, waste water produced can be collected in a water collection tank which may be weighed by the scale and used in the mass gain method. The scale may be replaced by load cells in some embodiments. The mass gain method, expressed in the following equation, estimates the mass difference before and after carbonation. The mass difference, together with water evaporated from the exothermic carbonation reaction, represents the mass gain due to carbon dioxide uptake or conversion. The carbonation reaction is exothermic in nature, and as a result some of the water used in the mixture evaporates and condenses on the inner walls of the enclosure 11 and is collected in the water collection tank. The mass of the waste water is added to the mass of the cured concrete products since it was part of the original mixture. 7 Final mass + (Mass of water loss-initial Mass')0091 C02Uptake = - Mass o -f - carbo -n -ated intermediate -

[0092] In some embodiments, the enclosure 11 may have an inlet valve to introduce fresh air into the chamber 11 a from the environment outside of the enclosure 1 1 . In another embodiment, fresh air may be supplied from a sub-compartment or another source (e.g., reservoir, tank, subchamber) that is part of the carbonation enclosure 11 . Fresh air may be introduced to fine tune a concentration of the CO2 inside the curing chamber 11 a. A sensor may be coupled to the freshair inlet valve to determine characteristics of the air entering the chamber. These characteristics may include, for instance, a mass flow rate, a temperature, a pressure, a humidity, and so on. The controller 20 may thus cause the air inlet valve to open or close. The air inlet valve may have a plurality of open position to vary a flow rate of air entering the chamber 11 a via the air inlet valve. The controller 20 may cause the air inlet valve 11 a to open at a selected position to reach the desired flow rate of gas exiting the chamber 11 a.

[0093] In some embodiments, it may be possible to recycle the gas exiting the curing chamber 1 1 a from the outlet valve. This recycled gas may be re-injected into the curing chamber 11 a via the inlet valve. The gas may be recycled to fine tune the CO2 concentration in side the chamber 1 1.Aggregate

[0094] In the particular embodiment where the alkaline materials are used to produce concrete products such as a ready mix concrete, an aggregate needs to be selected for producing the concrete mixture. Carbonated precast concrete is a composite material that is essentially composed of a binding medium within which are embedded fragments of aggregate. This composite material is hardened in an enriched CO2 environment in the enclosure described herein that performs a combined curing and grinding. The ready mix concrete can then be used to rapidly and easily produce concrete products such as concrete pipes, traffic barriers, walls including retaining walls, boxes including modular boxes, culverts, tiles, pavers, foundations, slabs including hollow-core slabs, patio slabs, steps, curbs, concrete masonry units, beams, floors, columns, manholes, sewage pipes, railroad ties, and other precast concrete products.

[0095] The ready-mix concrete is prepared by mixing the carbonated alkaline materials with aggregates, water and optionally a binder. The aggregate used is typically a binary blend of coarse aggregate and fine aggregate. Coarse aggregate generally refers to aggregate with particle size larger than 4.75 mm (No. 4 sieve). Fine aggregate refers to aggregate with particle size smaller than 4.75 mm. ASTM C33 specifies the quality requirements for coarse aggregate and fine aggregate. Similar specifications are also given by local government or regulatory authority, e.g., OPSS 1002, AASHTO M6 and AASHTO M80. The decision in selecting the right type and blend of aggregate is often influenced by the experience gained in manufacturing and evaluating conventional precast concrete, and also limited by supplying availability.

[0096] Among the required quality of aggregate, the maximum size and the grading of the particles are two important parameters. It is believed to affect the material cost, workability, surface quality and void content of precast concrete. Determined by the product type, application and minimum thickness (or depth) of precast concrete, the minimum clear spacing between reinforcing bars (if applicable), and the supplying availability, the maximum allowable size of coarse aggregate is often 37.5 mm (172”). The most frequently used maximum size of coarse aggregate is 19 mm (3 / 4”) or 9.5 mm (3 / 8”). For fine aggregate, it is allowed to contain a maximum of 5% (mass) particles coarser than 4.75 mm (No. 4 sieve) by ASTM C33. About the grading of aggregate, well-graded coarse or fine aggregate is generally preferred for precast concrete production, i.e., the aggregate is preferred to have relatively consistent or fair representation from every size of particle within the specified sieve sizes. For fine aggregate, an empirical factor called fineness modulus is also chosen to represent the weighted average size and distribution of the aggregate. It is obtained by summing the accumulated percentages retained on the sieves of the standard series: Nos. 4, 8, 16, 30, 50, and 100 (with openings 4.75, 2.36, 1.18, 0.6, 0.3 and 0.15 mm), and then dividing the sum by 100. The higher the fineness modulus, the coarser is the aggregate. According to the specification of ASTM C33, the fineness modulus of fine aggregate should be 2.3-3.1 .

[0097] Although generally accounting for 50-75% of the volume in carbonated precast concrete, aggregate is often considered as an inert filler. The possible impact of aggregate on the manufacture and performance of carbonated precast concrete has been long overlooked.

[0098] In one embodiment of the current disclosure, the disclosed carbonated precast concrete is made of aggregate with no more than 10% accumulated mass retained on No. 8 sieve (2.36 mm opening) and larger-size sieves. In another embodiment of current disclosure, the disclosed carbonated precast concrete is made of aggregate with 100% passing No. 8 sieve (2.36 mm opening). In another embodiment of current disclosure, the disclosed carbonated precast concrete is made of aggregate with 100% passing No. 16 sieve (1.18 mm opening). In another embodiment of current disclosure, the disclosed carbonated precast concrete is made of aggregate with 100% passing No. 30 sieve (0.6 mm opening). In another embodiment of current disclosure, the disclosed carbonated precast concrete is made of aggregate with 100% passing No. 50 sieve (0.3 mm opening). In another embodiment of current disclosure, the disclosed carbonated precast concrete is made of aggregate with 100% passing No. 100 sieve (0.15 mm opening). In another embodiment of current disclosure, the disclosed carbonated precast concrete is made of aggregate with 100% passing No. 200 sieve (0.075 mm opening). In a furtherembodiment of the present disclosure, the disclosed carbonated precast concrete is made of sieved fine aggregate with 100% passing No. 8 (2.36 mm) and removed with particle 100% passing No. 100 sieve (0.15 mm opening).

[0099] In the context of the present disclosure, the expression “no more than Y% accumulated mass retained on No. X sieve” implies that, for a given mass of aggregate (e.g., 1 kg) no more than Y% of that mass will be retained on the No. X sieve. For instance, saying “no more than 10% accumulated mass retained on No. 8 sieve (2.36 mm opening)” means that for one kilogram of aggregate, no more than 100 grams of that aggregate will be retained on the No. 8 sieve; the remaining 900 grams of the aggregate will pass through openings of the No. 8 sieve.

[0100] Additionally, the disclosed ready-mix or precast concrete, in some embodiments, is made of fine aggregate with varying density. In one embodiment, the disclosed ready-mix or precast concrete is made of normal-weight aggregate, with dry rodded density in the range of 1 100-1850 kg / m3. In another embodiment, the disclosed carbonated precast concrete is made of lightweight aggregate, with dry rodded density less than about 1100 kg / m3. In a further embodiment, the disclosed carbonated precast concrete is made of heavyweight aggregate, with dry rodded density greater than 2100 kg / m3, respectively.

[0101] The “dry rodded density” used herein refers to a mass per unit volume of dry aggregate, which includes the volume of the particles and the voids between the particles, compacted by rodding. Rodding compaction is a process by which a compaction force is applied to the aggregate to increase particle to particle contact and decrease the volume of the voids between those particles.

[0102] In addition, the disclosed ready-mix or precast concrete is made of fine aggregate from different sources. In one embodiment, the disclosed carbonated precast is made of natural origin, such as sand. In another embodiment, the disclosed carbonated precast is made of manufactured aggregate from natural origin, such as crushed stone fine, expanded perlite, expanded shale, and so on. In a further embodiment, the disclosed carbonated precast is made of manufactured aggregate from recycled sources, such as crushed glass, crushed air-cooled granulated blast furnace slag, crushed construction and demolition waste (recycled concrete, brick, and stone rubble), and so on. Furthermore, in one embodiment, the disclosed carbonated precast concrete is made of a combination of the above-mentioned aggregates in terms of their particle size, and / or source, and / or density. In some embodiments, some slag may be used as a binder whereassome other slag may be used as an aggregate. A difference between slag as a binder and slag as an aggregate pertains mainly the particle size; slag as aggregate is usually much coarser than the slag as binder. In some cases, slag as a binder may differ from slag as an aggregate by their chemical compositions and reactivity to carbon dioxide or water; to make a slag as a binder, it has to be ground sufficiently fine and it has to have the compounds to react with carbon dioxide or water to harden. In one embodiment, particles of slag as used as a binder are finer than 0.8 mm whereas particles of slag as used as an aggregate have a fineness of greater than 0.8 mm (i.e. they are coarser than 0.8 mm). Therefore, if the aggregate includes particles of slag, these particles of slag are coarser than 0.8 mm.

[0103] Additionally, the disclosed fine aggregate can be of natural, or manufactured, or recycled origin. Furthermore, the described fine aggregate may be normal weight, or lightweight, or heavy weight according to its density. The described fine aggregate can also be a combination of a plurality of the above-mentioned aggregates in terms of their particle size, and / or source, and / or density. Thus, the aggregate may have many portions by mass, each of these portions may include particles having a respective density, fineness, and origin. The disclosed carbonated precast concrete may have the advantage of requiring at least 50% less conditioning time than regular carbonated precast concrete. In addition, the disclosed carbonated precast concrete may have greater CO2 uptake, strength, and durability than regular carbonated precast concrete.

[0104] Herein, the expression “finer than X mm”, where “X” is a numerical value, means that a particle of the aggregate has passed or is capable of passing through a sieve with a nominal aperture size of “X” mm, by following the sieve analysis method instructed by ASTM C136 (Standard Test Method for Sieve Analysis of Fine and Coarse Aggregates). For instance, if a particle of the aggregate is finer than about 2.36 mm, it implies that this particle has passed (or is capable of passing) though a sieve with a nominal aperture size of 2.36 mm by following the ASTM C136 method. Similarly, the expression “coarser than Y mm”, where “Y” is a numerical value, means that a particle of the aggregate has retained on sieve with nominal aperture size larger than and equal to “Y” mm by following the ASTM C136 method.Binder, Water, and Additives

[0105] After the aggregate suitable for manufacturing the disclosed ready-mix or precast concrete is determined, attention is turned to other raw materials of the mixture to produce concrete products with the mixture. These raw materials can include binders, water and additives (e.g., chemical admixtures).

[0106] The binder(s) suitable for manufacturing the disclosed ready-mix or precast concrete can be reactive towards carbon dioxide. In some embodiments, the carbonated alkaline material is the sole binder in the mix. In other embodiments, Portland cement is further provided as an additional binder.

[0107] The binder(s) suitable for manufacturing the disclosed carbonated precast concrete may be any or a combination of cementitious and supplementary cementitious binders, which are termed conventional “binders” in this disclosure. The conventional binders are the ones currently accepted for normal (non-carbonated) precast concrete production. These binders may include: ordinary Portland cement (OPC), high alumina cement, white cement, calcium sulfoaluminate cement, magnesium cement, hydrated lime, supplementary cementitious materials including ground granulated blast furnace slag (GGBFS), fly ash, bottom ash, and natural and calcined pozzolanic materials, and OPC blended with limestone or supplementary cementitious materials.

[0108] The binder(s) suitable for manufacturing the disclosed carbonated precast concrete may include emerging binders, which have weak or no hydraulic activity and also have not been recognized as supplementary cementitious materials. The main characteristics of the emerging binders are low cost and low carbon footprint, because they are either derived from waste sources or manufactured with less energy consumption and CO2 emission than conventional cementitious binders. These binders include: belite cement, wollastonite, steel slag, bottom ash from municipal solid waste incineration, and so on.

[0109] The binder(s) suitable for manufacturing the disclosed carbonated precast concrete may include any combination of conventional binders and / or emerging binders. Preferably, the binder that is suitable for manufacturing the disclosed carbonated precast concrete contains at least 10% by weight emerging binders. More preferably, the binder that is suitable for manufacturing the disclosed carbonated precast concrete contains at least 25% by weight emerging binders. More preferably, the binder that is suitable for manufacturing the disclosed carbonated precast concrete contains at least 50% by weight emerging binders. More preferably, the binder that is suitable for manufacturing the disclosed carbonated precast concrete contains at least 75% by weight emerging binders. More preferably, the binder that is suitable for manufacturing the disclosed carbonated precast concrete contains 100% by weight emerging binders.

[0110] As shown in the examples below, carbonated steel slag may be used herein as the sole component of a binder for carbonated precast concrete production. “Steel slag” herein refers to the slag by-product produced from making steel. Steel slag may include slag produced from Basic Oxygen Furnaces (BOF), also known as slag from the Linz-Donawitz (LD) process, or LD slag. Steel slag may also include slag produced from Electric Arc Furnaces (EAF). Steel slag as used herein may further include ladle slag, which is produced as a by-product from a ladle refining operation. Steel slag as used herein may further include stainless steel slag generated from stainless steel production, which is mainly generated from the argon oxygen decarburization (AOD) and / or ladle metallurgy (LM) process. In addition, steel slag can be a combination of above slags. For example, “EBH slag” as used herein refers to EAF-BOF Hybrid, which is a type of steel slag formed of a mixture of EAF and BOF produced slags.

[0111] In other words, “slag” herein refers to the slag by-product produced from making steel and / or stainless steel. Steel slag may include slag produced from Basic Oxygen Furnaces (BOF). Steel slag may also include slag produced from Electric Arc Furnaces (EAF). Steel slag as used herein may further include ladle slag. It will be understood that “steel slag” as used herein excludes iron slag and blast furnace slag that are typically generated during iron production and that may be used in making cement, such as pozzolanic slag. Stainless steel slags are a by product of stainless steel production.

[0112] “Ladle slag” herein refers to a type of steel slag. Ladle slag is produced as a by-product from a ladle refining operation. In various steel making processes, molten steel produced in an EAF or BOF process undergoes an additional refining processes based on the quality of the desired steel. Additional fluxes and alloys are added to a ladle to remove the impurities within the steel and to produce steel with the desired properties. The reaction takes place in the presence of a slag in which the most significant oxides are SiO2, AI2O3, CaO, and MgO. This operation is known as ladle refining, because it is executed in the transfer ladle. During this process, additional steel slags are generated, which are ladle slags. It has been observed that the chemical compositions of ladle slag which are linked to the grade of the steel produced are highly variable and different from the chemical compositions of BOF and EAF steel slags. It has been observed that ladle slag shows higher aluminum oxide content and lower iron oxide content as compared to BOF and EAF steel slags. Generally, ladle slags exhibit a calcium oxide to silica oxide ratio of about 2.

[0113] “EBH slag” herein refers to EAF-BOF-Ladle Hybrid, which is a type of steel slag formed of a mixture of EAF and BOF and ladle produced slags.

[0114] In one embodiment, the steel slag used herein has a cumulative calcium silicate content (ex: CS + C2S + C3S phase concentration) of at least about 15% by weight. In one embodiment, the steel slag used herein has a cumulative calcium silicate content (ex: CS + C2S + C3S phase concentration) of at least about 20% by weight. In one embodiment, the steel slag used herein has a cumulative calcium silicate content (ex: CS + C2S + C3S phase concentration) of at least about 30% by weight. In one embodiment, the steel slag used herein has a cumulative calcium silicate content (ex: CS + C2S + C3S phase concentration) of at least about 40% by weight. In one embodiment, the steel slag used herein has a SiC>2 content of at least about 6% or more preferably at least about 15% by weight.

[0115] The steel slag may include a mixture of coarse slag pieces and fine slag pieces. Coarse slag pieces may have a Blaine fineness less than about 50 m2 / kg and fine slag pieces may have a Blaine fineness greater than about 50 m2 / kg. The coarse slag pieces, the fine slag pieces, or both may be land-filled as an outcome from typical steel making process. Received steel slag originating from waste (such as land-fill and / or industrial waste) may optionally be refined. Refining the steel slag may include filtering the received steel slag to separate fine slag pieces from coarse slag pieces. Alternatively, or additionally, refining the received steel slag may also include pulverizing the steel slag to a fine powder. In some exemplary embodiments, the filtered fine pieces are pulverized while coarser pieces are not pulverized. For example, for EAF steel slag, the slag may be pulverized to a Blaine fineness of at least 50 m2 / kg, and preferably about 180 m2 / kg. For example, for EBH steel slag (mix of EAF and BOF and ladle slag), the slag may be pulverized to a Blaine fineness of at least 100 m2 / kg and preferably about 240 m2 / kg. In other exemplary embodiments, the steel slag may be pulverized to a finer size. In another example, at least fifty percent of ground slag may be smaller than 100 microns, and at least ten percent of ground slag may be smaller than 50 microns, i.e., D(50) < 100 microns, and D(10) < 50 microns.

[0116] It will be understood that “steel slag” as used herein excludes iron slag and blast furnace slag that are typically generated during iron production and that may be used in making cement, such as pozzolanic slag.

[0117] Any potable water is suitable for the production of the disclosed carbonated precast concrete. The addition amount of water should be controlled to the minimum value for a desired workability of concrete mixture, for the considerations of reducing conditioning time and also achieving the desired concrete density with the available manufacturing tools.

[0118] Additives that are suitable for manufacturing the disclosed carbonated precast concrete include any or a combination of the following: air entraining admixture, water reducing admixture, water repellent admixture, accelerating admixture, retarding admixture, rheology modifier, efflorescence control admixture, foaming agent, alkali silica reaction inhibitor, shrinkage reducer, corrosion inhibiting admixture, pigment, material admixture, reinforcing fiber, polymer, and so on. The dosages of the additives used to manufacture the disclosed carbonated precast concrete follow the general rules which are known for people with ordinary skill in the art.

[0119] In some embodiments, the providing of the composition includes providing the composition including one or more chemical admixture and / or one or more material. The chemical admixture may include an accelerator, a retarder, a viscosity modifying agent, an air entertainer, a foaming agent, an alkali silica reaction inhibitor, an anti-wash-out, a corrosion inhibitor, a shrinkage reducer, a concrete crack reducer, a plasticizer, a super plasticizer, a sealer, a paint, a coating, a water reducer, a water repellant, an efflorescence controller, a polymer powder, a polymer latex, and a workability retainer. The mixing of the composition at 202 may include mixing the composition with one or more of cellulose fibers, glass fibers, micro synthetic fibers, natural fibers, polypropylene fibers, polyvinyl alcohol fibers, and steel fibers.

[0120] In some embodiments, the method 200 includes mixing the water, the aggregate, and the binder optionally including or being steel slag. In some embodiments, the method 200 includes mixing the water, the aggregate, and the binder having a binder content being from 8% to 50% by weight of the concrete mixture. The binder may be devoid of cement. The binder may consist of steel slag.

[0121] In the context of the present disclosure, the expressions “binder” and “cement” have different meaning. A cement, such as Ordinary Portland Cement, is a kind of binder. A cement may be considered a binder, but not all binders are cements.

[0122] In the embodiment shown, the method 200 includes mixing of the composition including the binder includes mixing the composition being free of another binder. In other words, only the binder that meets the MM ratio of at least 0.5 may be used in the composition.Alternatively, one or more second binder may be used. Preferably, a ratio of a mass of the binder to a sum of the mass of the binder plus a mass of the one or more second binder being at least 80%. Put differently, the binder that meets the MM ratio of at least 0.5 constitute at least 80% by weight of the total weight of binder used.Mixture and Optional Forming

[0123] There is provided a method of utilizing the ready-mix or precast concrete prepared according to the above to produce a concrete product. The method 200 is shown in Fig. 2. As explained above, a mixture is produced by mixing the carbonated alkaline material with an aggregate, water, and optionally a binder.

[0124] In the embodiment shown, the step 202 of the mixing of the carbonated alkali materials, the aggregate, the binder and the waterto produce the ready-mix concrete may include producing a wet mixture having a mixture water-to-binder ratio. Generally, the total binder content (i.e. carbonated alkali materials and any additional binder) in the mixture varies from 8% to 50% of total mass of the mixture, in accordance with the binder type and also the desired application. The water-to-binder ratio may be about 0.15-0.50. There are many suitable ways to perform the mixing of the concrete mixture, for example with a pan mixer.

[0125] Herein, there is optionally provided the step of imparting a form to the concrete mixture at which includes casting the mixture in a mould to provide a moulded intermediate. In such embodiments, the method 200 of the present embodiment can include an optional step of demoulding the moulded intermediate to provide a demoulded intermediate. In some embodiments, the carbon curing of the formed intermediate at may include curing the formed intermediate while the formed intermediate is still in the mould. Alternatively, the carbon curing at may include curing the demolded intermediate.

[0126] The imparting of the form to the concrete mixture may include forming and consolidating the mixture under compaction and vibration to provide the formed intermediate. In some embodiments, the imparting of the form may include transferring the freshly prepared mixture by any appropriate means and casting in a prepared mould. The mould may be made of steel, iron, aluminum, plastic, FRP or another material. The mould may be pre-lubricated prior to casting in order to facilitate the demoulding process. If using a wet mix, it may be consolidated within the mould by internal or external vibrators. In some cases, the consolidation step lasts no more than 120 seconds. Dry cast concrete may be compacted / pressed / pressurized / formed intothe mould by compaction and or vibration. The imparting of the form may include casting the mixture in a shape of a precast, a concrete pipe, a box culvert, a draining product, a paving slab, a floor slab, a traffic barrier, a wall manhole, a retaining wall, a paver, a tile, or a shingle.

[0127] In some embodiments, the method 200 may include demoulding the formed intermediate before the carbon curing of step 204. The method may include conditioning the formed intermediate until a water-to-binder ratio, which corresponds to a first water-to-binder ratio after the imparting of the form, reaches a second water-to-binder ratio lower than the first water- to-binder ratio. After the conditioning step, the conditioned intermediate may be demolded to provide a demolded conditioned intermediate. This demolded conditioned intermediate may then go through the carbon curing step at 204.

[0128] In some embodiments, the method 200 includes inserting a reinforcing material inside the mould before the casting of the concrete mixture. The inserting of the reinforcing material may include inserting bars made of the reinforcing material, the reinforcing material including one or more of carbon steel, stainless steel, and fiber reinforced polymer.

[0129] In some embodiments, the water-to-binder ratio before the conditioning may be about 0.2 with normal aggregates and from 0.07 to 0.1 with finer aggregates as described herein. The water-to-binder ratio may be about 0.15 before the conditioning. Thus, the finer aggregates may result in having to extract less moisture from the intermediate. This may, in turn, reduce a time of the condition step. Other water-to-binder ratios are contemplated depending of the binders and aggregates being used.

[0130] After a homogeneous mixture with a desired workability is obtained following the step 202 of mixing, the mixture may be emptied from the mixer and then transported to the molding place. The step of imparting a form to the mixture may require an amount of the mixture to be cast into a mould with pre-set dimensions and shape, followed with being leveled. Consolidation is then conducted to condense precast concrete mixture in the mold to the required thickness or height. Consolidation may be achieved through the known ways, such as any or a combination of vibration, compaction and compression.

[0131] After molding is completed, the consolidated precast concrete may be taken out of the mould or demolded immediately if it is rigid enough. Otherwise, the consolidated precast concrete may required to be maintained in the mold for a period generally less than 24 hours. This may be referred to as a pre-curing step. This process may help the consolidated precast concrete toobtain sufficient green strength before being demolded. It happens when a wet concrete mixture is used for precast concrete forming. Pre-curing, if required, may be conducted at room temperature. It can also be accelerated at elevated temperature.Conditioning

[0132] The conditioning step can be performed on the mixture obtained at step 202 without imparting any form to the mixture. In embodiments where a form is imparted, although the conditioning step may start when the consolidated precast concrete remains in the mould, it may alternatively occur after the formed intermediate has been demolded. It may be conducted at room conditions with a temperature of 15-28°C and a relative humidity of 20-60%. In some embodiments, the conditioning 204 may be assisted with a forced air circulation by a fan. Other known ways of reducing the moisture, e.g. heat, can be alternatively used during the conditioning step. Alternatively, no forced air circulation may be used during the conditioning step, if energy saving is preferred and a longer time for conditioning is acceptable. This conditioning step may help to reduce the moisture content of precast concrete through water evaporation. The released moisture leaves numerous pores inside the consolidated precast concrete, which may allow to achieve a desired CO2 uptake and a uniform carbonation throughout the whole precast concrete product.

[0133] The duration of the conditioning step may be determined by the desired extent of initial water or moisture loss from the consolidated precast concrete, which is affected by the dimension and initial water-to-binder ratio of precast concrete, and other variables. As a general rule of thumb, for a precast concrete with a thickness of 30 mm or greater, an initial water loss of 20- 80% (by mass) may be required for the conditioned precast concrete to achieve satisfactory CO2 uptake and strength as well as 100% CO2 penetration, if carbonation curing is required to be completed in hours instead of days.

[0134] The degree of CO2 penetration may be visually determined by spraying phenolphthalein indicator onto the whole cross section of carbonated precast concrete after it is broken by strength testing. The percentage of the area without pink color against the whole cross area is estimated as degree of CO2 penetration. For example, a 100% CO2 penetration is obtained if no pink color is observed in the tested cross section area, while a 50% CO2 penetration is obtained if pink color occupies a half of the tested cross section area.

[0135] Due to the use of finer aggregate disclosed herein, the conditioning time required for manufacturing the disclosed carbonated precast concrete may be significantly decreased. As shown in the examples described below, carbonated precast concrete made of finer aggregate disclosed herein may need a conditioning time only 0.25 hour, instead of a conditioning time of 1 hour required for precast concrete with regular-size aggregate. For predetermined binder content and water-to-binder ratio, precast concrete with coarser aggregate would have a thicker layer of paste to cover each aggregate particle and also possibly more paste agglomerating among the pores between aggregate particles. By reducing the particle size of fine aggregates, the increased surface area of aggregate particles would need more paste to cover. This may help to reduce the thickness of paste coverage for each aggregate particle, and also reduce the tendency of paste agglomeration in the pores. As a result of this paste thinning effect, CO2 gas may penetrate to the reaction site more easily, and also the formed calcite may precipitate more easily as well during the carbonation curing process. Therefore, a shorter conditioning time may be possible for manufacturing carbonated precast concrete made of finer aggregates disclosed herein.

[0136] In some embodiments, the conditioning of the formed intermediate includes conditioning the formed intermediate at a temperature ranging from 15°C to 28 °C and with a relative humidity ranging from 30% to 60%. In some embodiments, the conditioning of the formed intermediate includes conditioning the formed intermediate until from 20% to 80% by weight of the water is evaporated. In some embodiments, the conditioning of the formed intermediate includes exposing the formed intermediate to a forced air flow.

[0137] The conditioning time is a function of the size or volume of the concrete product. Longer conditioning time is needed for a thicker or larger concrete product. The conditioning time for a determined concrete product may be reduced by at least 50% with the suggested aggregate. Another factor influencing the conditioning time is the velocity of the air flow when forced drying is used, the relative humidity of the environment in which the intermediate is being conditioned, the temperature of this environment, and the microstructures (capillaries and pores) of the intermediate.Hydration

[0138] For carbonated precast concrete made of binders with hydraulic activity such as OPC, hydration curing may optionally be implemented to help carbonated precast concrete achievingfull strength. During the hydration curing, carbonated precast concrete products are stored in humid environment for 1 day or longer following the general procedure known in the industry.Moisturizing

[0139] The carbonated precast concrete may be moisturized. This moisturizing step may include, for example, submerging the cured intermediate in water; spraying the cured intermediate with water; and / or misting the cured intermediate with water. In certain embodiments, therefore, the cured intermediate is moisturized by being soaked in tap water or water saturated with hydrated lime for a period not longer than 24 hours, or by being sprinkled, sprayed and / or misted with tap water. In certain embodiments, this moisturizing is performed for period of time from 0.5 to 48 hours. The preferred moisture content increase for the moisturized carbonated precast concrete is 0.5% by weight or higher. There can be a delay of up to 24 hours between the proposed moisturizing step and the followed post-hardening treatment. Such a moisturizing step can be advantageous for carbonated precast concrete made of a binder with hydraulic activity. Optionally, water used for soaking / spraying can contain minerals / chemicals like efflorescence reducer admixture or water repellent. Alternatively, carbonated precast concrete can be surrounded by water vapour during the post-hardening treatment.

[0140] At step 206, a carbon curing is performed to obtain the concrete product. In some embodiments, the carbonation reaction between calcium-rich materials and carbon dioxide occurs once calcium leached from the material and CO2 are dissolved in water. In a concrete sample, the carbonation reaction generally happens at a specified pore saturation. Once the pores are filled with water and the saturation rate is at or near 100%, there is little to no carbonation reaction. This observation is also valid when there is no water in the pore, or where the pore saturation is zero percent. The optimum pore saturation, or in simplerterms, the moisture content of the mix, results in the highest carbonation reaction rate. Diverging from the optimum moisture content may lead to a lower carbonation reaction and lower concrete performance.

[0141] In some embodiments, the concrete product may be wet or moisturized. In some embodiments, the carbonated precast concrete is soaked in tap water or water saturated with hydrated lime for a period not longer than 24 hours, or by being sprinkled with tap water. The preferred moisture content increase for the moisturized carbonated precast concrete is 0.5% by weight or higher, for example at least 0.55 %, at least 0.6 %, at least 0.65 %, at least 0.7 %, or at least 0.75 %. There can be a delay of up to 24 hours between the optional wetting / moisturizing step and the followed post-hardening treatment. The described wetting or moisturizing step canbe advantageous for carbonated precast concrete made of a binder with hydraulic activity. Optionally, water used for soaking / spraying can contain minerals / chemicals like efflorescence reducer admixture or water repellent. Alternatively, carbonated precast concrete can be surrounded by water vapour during the post-hardening treatment. Therefore, in some embodiments the steps of moisturizing and curing may overlap or may occur concurrently.

[0142] In some embodiments, during the water absorption testing, carbonated precast concrete is immersed in water for 24 hours and then oven-dried for not less than 24 hours at 100- 1 15°C.Computing device

[0143] With reference to Fig. 3, an example of a computing device 300 is illustrated. For simplicity only one computing device 300 is shown but the system may include more computing devices 300 operable to exchange data. The computing devices 300 may be the same or different types of devices. The controller 20 may be implemented with one or more computing devices 300. Note that the controller 20 can be implemented as part of a full-authority digital engine controls (FADEC) or other similar device, including electronic engine control (EEC), engine control unit (ECU), electronic propeller control, propeller control unit, and the like. In some embodiments, the controller 20 is implemented as a Flight Data Acquisition Storage and Transmission system, such as a FAST™ system. The controller X may be implemented in part in the FAST™ system and in part in the EEC. Other embodiments may also apply.

[0144] The computing device 300 comprises a processing unit 302 and a memory 304 which has stored therein computer-executable instructions 306. The processing unit 302 may comprise any suitable devices configured to implement the methods of the present disclosure such that instructions 506, when executed by the computing device 500 or other programmable apparatus, may cause the functions / acts / steps performed as part of the methods of the present disclosure as described herein to be executed. The processing unit 502 may comprise, for example, any type of general-purpose microprocessor or microcontroller, a digital signal processing (DSP) processor, a central processing unit (CPU), an integrated circuit, a field programmable gate array (FPGA), a reconfigurable processor, other suitably programmed or programmable logic circuits, or any combination thereof.

[0145] The memory 304 may comprise any suitable known or other machine-readable storage medium. The memory 304 may comprise non-transitory computer readable storagemedium, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. The memory 304 may include a suitable combination of any type of computer memory that is located either internally or externally to device, for example random-access memory (RAM), read-only memory (ROM), compact disc read-only memory (CDROM), electro-optical memory, magnetooptical memory, erasable programmable read-only memory (EPROM), and electrically-erasable programmable read-only memory (EEPROM), Ferroelectric RAM (FRAM) or the like. Memory 304 may comprise any storage means (e.g., devices) suitable for retrievably storing machine-readable instructions 306 executable by processing unit 302.

[0146] The methods and systems for producing carbonated alkaline materials described herein may be implemented in a high level procedural or object oriented programming or scripting language, or a combination thereof, to communicate with or assist in the operation of a computer system, for example the computing device 300. Alternatively, the methods and systems for producing carbonated alkaline materials may be implemented in assembly or machine language. The language may be a compiled or interpreted language. Program code for implementing the methods and systems for producing carbonated alkaline materials may be stored on a storage media or a device, for example a ROM, a magnetic disk, an optical disc, a flash drive, or any other suitable storage media or device. The program code may be readable by a general or specialpurpose programmable computer for configuring and operating the computer when the storage media or device is read by the computer to perform the procedures described herein. Embodiments of the methods and systems for producing carbonated alkaline materials may also be considered to be implemented by way of a non-transitory computer-readable storage medium having a computer program stored thereon. The computer program may comprise computer- readable instructions which cause a computer, or more specifically the processing unit 302 of the computing device 300, to operate in a specific and predefined manner to perform the functions described herein.

[0147] Computer-executable instructions may be in many forms, including program modules, executed by one or more computers or other devices. Generally, program modules include routines, programs, objects, components, data structures, etc., that perform particular tasks or implement particular abstract data types. Typically the functionality of the program modules may be combined or distributed as desired in various embodiments.

[0148] The embodiments described herein are implemented by physical computer hardware, including computing devices, servers, receivers, transmitters, processors, memory, displays, andnetworks. The embodiments described herein provide useful physical machines and particularly configured computer hardware arrangements. The embodiments described herein are directed to electronic machines and methods implemented by electronic machines adapted for processing and transforming electromagnetic signals which represent various types of information. The embodiments described herein pervasively and integrally relate to machines, and their uses; and the embodiments described herein have no meaning or practical applicability outside their use with computer hardware, machines, and various hardware components. Substituting the physical hardware particularly configured to implement various acts for non-physical hardware, using mental steps for example, may substantially affect the way the embodiments work. Such computer hardware limitations are clearly essential elements of the embodiments described herein, and they cannot be omitted or substituted for mental means without having a material effect on the operation and structure of the embodiments described herein. The computer hardware is essential to implement the various embodiments described herein and is not merely used to perform steps expeditiously and in an efficient manner.

[0149] The term “connected” or "coupled to" may include both direct coupling (in which two elements that are coupled to each other contact each other) and indirect coupling (in which at least one additional element is located between the two elements).

[0150] The technical solution of embodiments may be in the form of a software product. The software product may be stored in a non-volatile or non-transitory storage medium, which can be a compact disk read-only memory (CD-ROM), a USB flash disk, or a removable hard disk. The software product includes a number of instructions that enable a computer device (personal computer, server, or network device) to execute the methods provided by the embodiments.

[0151] It is noted that various connections are set forth between elements in the preceding description and in the drawings. It is noted that these connections are general and, unless specified otherwise, may be direct or indirect and that this specification is not intended to be limiting in this respect. A coupling between two or more entities may refer to a direct connection or an indirect connection. An indirect connection may incorporate one or more intervening entities. The term “connected” or "coupled to" may therefore include both direct coupling (in which two elements that are coupled to each other contact each other) and indirect coupling (in which at least one additional element is located between the two elements).EXAMPLES

[0152] In one example, a type of steel slag went through ten 2-hour cycles of carbonation (20 hours in total) at ambient pressure and 99% CO2 concentration, followed by 1 -minute grinding periods in a ring and puck mill. The steel slag used was a mix of BOF, ladle slag, and EAF sourced from a Canadian steel manufacturing plant. A control mix of the same steel slag mix was kept in the same curing conditions for 20 hours in the absence of grinding. The steel slag mix which was subjected to concurrent grinding and curing showed ~28% CO2 uptake (in terms of mass of steel slag) as opposed to the control mix which had only ~14% CO2 uptake (Fig. 3). The curing was performed at 15 PSI and 50% CO2 concentration.

[0153] In another example, 30% of fine aggregates were replaced with the CO2 enhanced steel slag (partial replacement). In another example 60% of coarse aggregates were replaced with the CO2 enhanced steel slag as binder.

[0154] It is further noted that various method or process steps for embodiments of the present disclosure are described in the preceding description and drawings. The description may present the method and / or process steps as a particular sequence. However, to the extent that the method or process does not rely on the particular order of steps set forth herein, the method or process should not be limited to the particular sequence of steps described. As one of ordinary skill in the art would appreciate, other sequences of steps may be possible. Therefore, the particular order of the steps set forth in the description should not be construed as a limitation.

[0155] Furthermore, no element, component, or method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the claims. As used herein, the terms “comprises”, “comprising”, or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

[0156] While various aspects of the present disclosure have been disclosed, it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible within the scope of the present disclosure. For example, the present disclosure as described herein includes several aspects and embodiments that include particular features. Although these particular features may be described individually, it is within the scope of thepresent disclosure that some or all of these features may be combined with any one of the aspects and remain within the scope of the present disclosure. References to “various embodiments,” “one embodiment,” “an embodiment,” “an example embodiment,” etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. The use of the indefinite article “a” as used herein with reference to a particular element is intended to encompass “one or more” such elements, and similarly the use of the definite article “the” in reference to a particular element is not intended to exclude the possibility that multiple of such elements may be present.

[0157] The embodiments described in this document provide non-limiting examples of possible implementations of the present technology. Upon review of the present disclosure, a person of ordinary skill in the art will recognize that changes may be made to the embodiments described herein without departing from the scope of the present technology. For example, although steel slag is provided as the main example of the alkaline materials, the present disclosure contemplates any other type of alkaline material as described herein. Yet further modifications could be implemented by a person of ordinary skill in the art in view of the present disclosure, which modifications would be within the scope of the present technology.

Claims

CLAIMS1 . A method of producing a carbonated alkaline material, comprising: sealing an alkaline material in an enclosure, the alkaline material having a first particle size characteristic and a first specific surface area; curing the alkaline material within the enclosure in the presence of carbon dioxide ; and during the curing of the alkaline material and within the enclosure, grinding the alkaline material to produce the carbonated alkaline material, the carbonated alkaline material having a second particle size characteristic that is different from the first particle size characteristic and / or having a second specific surface area that is different from the first specific surface area.

2. The method as defined in claim 1 , wherein the first and second particle size characteristic include an average particle diameter.

3. The method as defined in claim 2, wherein the average particle diameter of the carbonated alkaline material is at least 1 % less than that of the alkaline material.

4. The method as defined in claim 1 , wherein the first and second particle size characteristic is defined by a D50 of particles.

5. The method of claim 4, wherein the D50 of the alkaline material is at least 1 % different from the D50 of the carbonated alkaline material.

6. The method of any one of claims 1 to 5, wherein the second specific surface area of the carbonated alkaline material is at least 1 % different from the first specific surface area of the alkaline material.

7. The method as defined in any one of claims 1 to 6, further comprising providing carbon dioxide within the enclosure at a concentration of at least 0.5% by volume and at a gauge pressure of at least 0.01 psig.

8. The method as defined in any one of claims 1 to 7, wherein the grinding is performed intermittently and the curing in the presence of carbon dioxide is performed continuously.

9. The method as defined in any one of claims 1 to 8, wherein the alkaline material includes steel slag, wollastonite, recycled concrete, cements, stainless steel slag, iron slag, fly ash, calcium hydroxide, calcium oxide, periclase Portland cement clinker, olivine, pyroxenes, plagioclase, feldspars, and / or calcium silicate materials.

10. The method as defined in any one of claims 1 to 9, wherein the alkaline material comprises one or more of a silicate based material including CasSiOs, CaSiCh, Ca2SiC>4, Mg2SiC>4, CaMg(SiC>3)2, and CaAl2Si2Os.1 1 . The method as defined in any one of claims 1 to 10, wherein the alkaline material is steel slag, the steel slag comprising at least one of EAF, BOF, and ladle steel slag.

12. The method as defined in any one of claims 1 to 11 , further comprising mixing the carbonated alkaline material with an aggregate and water to produce one of: a readymix concrete; a dry-cast concrete; and a precast concrete.

13. The method as defined in claim 12, further comprising mixing the carbonated alkaline material with a binder and / or an additive.

14. A method of processing an alkaline material having a first particle size characteristic, the method comprising grinding the alkaline material while concurrently curing the alkaline material using carbon dioxide to produce, once the curing is complete, a carbonated alkaline material having a second particle size characteristic that is different from the first particle size characteristic.

15. The method of claim 14, wherein the second particle size characteristic includes a smaller particle size and / or a larger specific surface area relative to the first particle size characteristic of the alkaline material.

16. A method of producing a carbonated alkaline material comprising grinding an alkaline material and curing the alkaline material using carbon dioxide, the grinding and the curing occurring simultaneously within a sealed enclosure.

17. A system for producing a carbonated alkaline material, comprising an enclosure defining a curing chamber and configured for sealing an alkaline material therein, a source of carbon dioxide in communication with the enclosure to feed the carbon dioxide into the curing chamber and cure the alkaline material, and a grinder operable to grind thealkaline material while exposed to the carbon dioxide to produce the carbonated alkaline material, the carbonated alkaline material having a smaller particle size and / or a larger specific surface area relative to the alkaline material.

18. The system of claim 17, wherein the grinder itself defines the enclosure, the curing chamber being formed within the grinder.

19. The system of claim 17, wherein the grinder is located within the enclosure.

20. A carbonated alkaline material produced by curing an alkaline material in the presence of carbon dioxide, the carbonated alkaline material having a smaller particle size and / or a larger specific surface area relative to the alkaline material.

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