Compositions and preparation methods for auxiliary cement-based materials

Abstract

To reduce the environmental footprint of the cement and mining industries, this invention provides a method for producing auxiliary cement-based materials (SCM) from globally abundant input materials. [Solution] The SCM production method includes contacting the input flow with a mechanical-thermal activating agent; heat-treating the input flow to form a heat-treated input flow; and cooling the heat-treated input flow to obtain an auxiliary cement-based material. The method may further include carbonating the heat-treated input flow. The method may further include modifying the network structure with a mechanical-thermal activating agent. A composition comprising calcium silicate hydrate bond; auxiliary cement-based material; and a mechanical-thermal activating agent. The composition may further include a carbonate. The composition may further include biomass.

Description

Technical Field

[0001] Cross - reference to Related Applications This application is a continuation - in - part bypass of PCT Patent Application No. PCT / CA2023 / 051157, filed on August 31, 2023, entitled "Compositions for Supplementary Cementitious Material and Methods of Making", which claims priority and the benefit of the filing of U.S. Provisional Patent Application No. 63 / 456,636, filed on April 3, 2023, entitled "Compositions for Supplementary Cementitious Material and Methods of Making". The specification and claims of the latter are incorporated herein by reference.

[0002] The present invention relates to methods of producing and compositions of supplementary cementitious materials (SCMs).

Background Art

[0003] Concrete has been an important building material for thousands of years and continues to be widely used today. Cement, the binding component of concrete, enables hardening of the composite material at ambient temperature. Many binder chemicals have been used to make concrete, but Portland cement and its variants have been the main binders for nearly 200 years. Unfortunately, Portland cement production is a highly CO₂ - intensive process, accounting for approximately 8% of global anthropogenic CO₂ emissions. Cement demand is predicted to increase by 12% - 23% by 2050, but the need for the complete decarbonization of the global economy runs counter to this increase in demand. Therefore, there is a need to reduce the specific CO₂ emissions of cement production, especially as production volumes are increasing.

[0004] One approach to reducing CO2 emissions from cement is to develop blends with auxiliary cementitious materials that can replace Portland cement in concrete mixtures. These materials include by-product ashes from combustion such as granular blast furnace slag ("GGBFS") and coal fly ash; calcined clays such as metakaolin; and natural pozzolans such as volcanic ash. However, the supply of these materials is geographically and volcanically limited compared to the enormous demand for cement, and their suitability as cementitious reagents varies between production plants and over time.

[0005] Fly ash is a partially vitreous aluminosilicate by-product of coal combustion, frequently used in hydraulic cement mixtures, for example, to improve fluidity and to create pozzolanic reactions that enhance concrete properties. However, only certain coals and combustion processes produce fly ash of acceptable quality for use in concrete. On the other hand, GGBFS is an iron-producing vitreous CaO-SiO2 by-product that possesses many advantageous properties when incorporated into concrete, but its supply is limited due to the small number of operating blast furnaces.

[0006] While natural pozzolanes can be effective supply chain manufacturing (SCM), they require the extraction of non-renewable resources and often necessitate significant processing, such as calcination, to enhance their reactivity. Therefore, there is a need for engineered cementitious reagents with low or zero process CO2 emissions that can be produced ubiquitously from globally abundant input materials, are reactive in cementitious systems, and whose production site can be selected based on market needs. This would provide cementitious reagents that can be reliably produced and supplied to meet global demand while reducing CO2 emissions in Portland cement production.

[0007] Mineral tailings, construction waste, clay, landfill / bottom ash, and mineral waste are all potential sources of raw materials for SCM production. These waste flows often contain minerals such as silica, alumina, and iron, which are key components of conventional SCM such as fly ash and slag. By extracting these minerals from waste flows and processing them to meet the required specifications, they can be used as sustainable alternatives to conventional SCM. Furthermore, using waste materials as raw materials for SCM can offer environmental benefits such as reduced waste disposal, decreased energy consumption, and lower greenhouse gas emissions. With the increasing demand for low-carbon construction materials, utilizing waste materials as resources for SCM production can help meet sustainability goals and reduce the environmental impact of the cement and concrete industry.

[0008] SCM can be pozzolanic or potentially hydraulic. Pozzolanic SCMs, such as fly ash, react with calcium hydroxide and water at high pH to form compounds containing CSH bonds. Fly ash is an amorphous glass that thereby reacts with calcium hydroxide and water to form CSH bonds. Pozzolanic SCMs, such as fly ash, silica fume, and crushed granular blast furnace slag, react with calcium hydroxide to form additional CSH gels via a pozzolanic reaction that occurs between pozzolanic and calcium hydroxide in the presence of water.

[0009] Potentially hydraulic SCMs such as slag react with water to form CSH bonds, eliminating the need for calcium hydroxide. For example, Portland cement forms a CSH gel through a hydraulic reaction between the cement and water.

[0010] Highly crystallinity inert materials do not react with calcium hydroxide and water. Inert fillers such as tailings do not react with calcium hydroxide; therefore, they do not exhibit cementitious activity. Thus, SCM should be reactive when mixed with calcium hydroxide and water and participate in CSH bond formation. In some cases, SCM is inert but can still meet the ASTM C 618 strength activity requirements due to its filler effect. Therefore, inert materials such as tailings and mineral waste need to be sufficiently activated so that they react with calcium hydroxide and / or water to form CSH bonds that confer hardening properties.

[0011] Despite the abundance of inert fillers, they lack the reactivity to function as supply chain materials (SCMs). Therefore, to reduce overall greenhouse gas ("GHG") emissions from construction material manufacturing, including cement production, and to mitigate the environmental impact of waste materials such as mineral tailings, it is necessary to produce reactive SCMs from abundant input materials, such as mineral tailings. Furthermore, the energy requirements for preparing SCMs must also be reduced.

[0012] Crystalline minerals such as tailings, aggregates, dust, sand, and clay are not typically used as auxiliary cementitious materials (SCMs) in concrete because they do not exhibit pozzolanic or hydraulic properties. Crystalline materials do not react with calcium hydroxide in the cement paste to form additional CSH gels. Consequently, they do not offer the same advantages as SCMs and are not typically used in that way in concrete.

[0013] One common approach to converting crystalline materials into SCMs is through thermal activation, which involves heating the material to high temperatures to induce chemical changes that create a reactive phase. For example, the firing of kaolin clay can produce metakaolin, a pozzolanic material that can be used as an SCM in concrete. However, thermal activation is typically carried out at high temperatures, exceeding 700°C for clays and over 1000°C for silicates and / or aluminosilicates, in order to induce structural changes in the crystalline network that affect amorphousness.

[0014] While traditional SCMs such as fly ash and slag have been useful in improving the sustainability and performance of concrete, the need for more consistent, environmentally friendly, and cost-effective alternatives is driving the search for new and innovative SCMs. Waste minerals such as tailings, construction waste, clay, bottom / landfill ash, and / or aggregate dust may be viable solutions to address the significant challenges associated with the global availability of large quantities of SCM. This approach not only provides a substantial source of sustainable building materials but also helps mitigate the environmental impacts of both the mining and construction industries. [Overview of the project] [Problems that the invention aims to solve]

[0015] This invention discloses the production of SCM from globally abundant input materials to reduce the environmental footprint of cement and mining. The invention also produces SCM at temperatures below 1000°C to reduce energy requirements and avoid carbonate decomposition for SCM preparation. Furthermore, the invention relates to an additional carbonation step for faster CO2 sequestration due to structural defects created after mechanical-thermal and chemical treatments, as well as higher reactivity. In addition, carbonated SCM may exhibit reduced water demand for mortar after the carbonation process. [Means for solving the problem]

[0016] Summary of the Invention Embodiments of the present invention relate to a method for producing an auxiliary cement-based material, the method comprising: contacting an input flow containing a crystalline and / or low-crystalline lattice with a mechanical-thermal activation aid; heat-treating the input flow to form a heat-treated input flow; sequestrating ions; breaking down the lattice of the input flow; and cooling the heat-treated input flow. In another embodiment, the method further comprises carbonizing the heat-treated input flow.

[0017] In another embodiment, the method further includes an oxidizing environment. In another embodiment, the method further includes a reducing environment. In another embodiment, the method further includes an inert environment.

[0018] In another embodiment, the method further comprises carbonizing the heat-treated feed stream. In another embodiment, the method further comprises co-milling the feed stream and the mechanical-thermal activator. In another embodiment, the method further comprises pelletizing the feed stream and the mechanical-thermal activator. In another embodiment, the method further comprises milling the heat-treated feed stream. In another embodiment, the method further comprises reducing the vitrification temperature.

[0019] In another embodiment, the mechanical-thermal activator includes biomass. In another embodiment, the method further includes thermal decomposition of the biomass. In another embodiment, the input flow includes aluminosilicate. In another embodiment, the mechanical-thermal activator includes alkali metal ions. In another embodiment, the mechanical-thermal activator includes alkaline earth metal ions. In another embodiment, the method further includes contacting the aluminosilicate with alkali metal ions. In another embodiment, the method further includes contacting the aluminosilicate with alkaline earth metal ions.

[0020] In another embodiment, heat treatment of the input flow includes heating the input flow and the mechanical-thermal activator to a temperature of about 400°C to about 1000°C. In another embodiment, the input flow includes recycled concrete aggregate. In another embodiment, the input flow includes kaolinite-rich clay. In another embodiment, the input flow includes recycled concrete powder.

[0021] Further scope of the applicability of the present invention is partially described in the following detailed description in conjunction with the accompanying drawings, and may become partially apparent to those skilled in the art by considering the following, or may be acquired through the practice of the present invention. The objects and advantages of the present invention may be realized and achieved by means and combinations particularly indicated in the appended claims. [Brief explanation of the drawing]

[0022] The accompanying drawings incorporated herein and forming part of herein illustrate one or more embodiments of the invention and, together with the description, help to illustrate the principles of the invention. The drawings are for illustrative purposes only and should not be construed as limiting the invention. In the drawings, [Figure 1] This is a process flow diagram illustrating the production of (non-carbonated) SCM from waste minerals containing silicates and / or aluminosilicates according to embodiments of the present invention. [Figure 2] This table shows the reactivity of SCM produced from mineral tailings and aggregate fine powder to a control sample in one embodiment of the present invention, regarding thermal release. [Figure 3] This table shows the strength activity indices of SCM (with and without carbonation) prepared from various sources after 20% cement replacement in a mortar mixture according to ASTM C618, according to one embodiment of the present invention. [Figure 4] This figure shows the synergistic effect of biomass, alkali metals, and aluminosilicates during heat treatment according to one embodiment of the present invention. [Figure 5]A photograph of SCM prepared by pelletization of feedstock and activation aids before and after heat treatment, according to an embodiment of the present invention, is shown.

Mode for Carrying Out the Invention

[0023] Detailed Description of the Invention Embodiments of the present invention relate to a method for manufacturing SCM, the method comprising contacting feedstock with a mechanical-thermal activation aid; heat-treating the feedstock to activate the feedstock; and milling the activated feedstock to form an auxiliary cementitious material. In some embodiments, after thermal activation, a dispersant can be added to permanently sequester CO2 in the form of carbonate in the SCM after thermal activation, allowing the SCM to be carbonated in a wet state. SCM carbonation can also reduce the water demand during SCM production. After carbonation, the produced SCM can be dried and ball-milled to form a final auxiliary cementitious material for use in a concrete mixture. Carbonation can be performed in a dry state by contacting the SCM with a source of CO2 gas. The contact can occur in a rotary cylinder, fluidized bed, grinding mill, or a combination thereof. The degree of carbonation depends on the reactive alkali or alkaline earth metals in the SCM. Reactive alkali metals or alkaline earth metals can include, but are not limited to, sodium, potassium, calcium, magnesium, or combinations thereof. In certain embodiments, when biomass is used as the activation aid, the char produced by biomass pyrolysis can sequester CO2. The SCM produced by mechanical-thermal treatment can increase the reaction rate of carbonation. Without being limited to a particular theory, the increased reaction rate may be due to a higher degree of disordered lattice structure and higher surface area.

[0024] Embodiments of the present invention relate to a method for producing a cement-based reagent, the method comprising: contacting input material with a mechanical-thermal activation aid; heat-treating the input material to activate it; milling the activated input material to form an auxiliary cement-based material; contacting the auxiliary cement-based material with calcium hydroxide and a base to form an auxiliary cement-based material mixture; hardening the auxiliary cement-based material mixture; and contacting the auxiliary cement-based material mixture with a cement mixture. Hardening of the auxiliary cement-based material mixture may be performed to test the reactivity of the auxiliary cement-based material mixture. Contacting the cement mixture with the auxiliary cement-based material mixture may involve substituting cement with the auxiliary cement-based material in a mortar mixture.

[0025] Embodiments of the present invention relate to compositions comprising an activating input material; a mechanical-thermal activating aid; and, when used in mortar and / or concrete mixtures, a calcium silicate hydrate bond. The compositions may further comprise carbonates derived from sequestered CO2.

[0026] Embodiments of the present invention relate to a method for producing SCM from globally abundant and locally available input materials, including but not limited to mineral waste streams, mineral tailings, construction waste, clay, sand, or combinations thereof. The present invention also relates to a method for producing SCM by vitrification with a mechanical-thermal activation aid. SCM can be used to replace Portland cement in concrete mixtures. For example, up to 20% of Portland cement may be replaced with SCM in the concrete mixture, depending on the reactivity of the SCM.

[0027] As used herein, the term "ASTM C618" refers to the standard specification for coal fly ash and raw or calcined natural pozzolanes for use in concrete, in accordance with the ASTM International Standard.

[0028] The term "fine powder" is defined herein as a material (such as ore) that has been finely crushed or powdered.

[0029] The terms “tailing” or “mineral tailing” are defined herein as the material remaining after the process of separating the valuable fraction from the uneconomical fraction of the material.

[0030] The terms “auxiliary cement materials” or “SCM” are defined herein as materials and / or compounds added to concrete to improve its performance and reduce its environmental impact. SCM reacts with calcium hydroxide or portlandite present in the cement paste to form calcium silicate hydrate (CSH) gel, in addition to the calcium silicate hydrate (CSH) formed from the cement.

[0031] The term "mechanical-thermal activation aid" is defined herein as a material and / or compound that reduces the temperature at which a material vitrifies and / or acts as a network modifier to modify the network structure in a Si-O, Al-O, and / or Al-Si-O matrix. Mechanical-thermal activation aids can improve the reactivity of a material.

[0032] The term "vitrification" is defined herein as the conversion of a material into glass or amorphous material by heat and fusion.

[0033] The term “Input Materials” is defined herein as materials and / or compounds from which SCM may originate. Input Materials include, but are not limited to, mineral tailings (zinc, lead, nickel, and copper tailings, or combinations thereof); aggregate powder; clay (muscovite, illite, kaolinite clay, blue clay, or combinations thereof); concrete aggregate (recycled concrete aggregate, recycled concrete powder, or combinations thereof); sand (silica sand, bedding sand, or combinations thereof); mature fine tailings, shale ash, coal bottom ash, landfill ash, or combinations thereof; and natural pozzolanes (including, but not limited to, zeolites, volcanic ash, or combinations thereof).

[0034] The term "heat treatment" is defined herein as applying heat to a material and / or compound.

[0035] As used herein, the term “source” may refer to a first compound from which a second compound is derived through a chemical reaction. For example, a source of sodium oxide may be sodium carbonate, which is approximately 58% sodium oxide. Sodium carbonate can be converted to sodium oxide through a chemical reaction.

[0036] As used herein, the term “environment” refers to physical and / or chemical conditions or combination of conditions that affect a reaction. For example, an oxidizing environment may be a reagent included in a chemical reaction that assists or carries out an oxidation reaction.

[0037] This method can enhance the strength, durability, and other properties of concrete. It can also enable the production of concrete at a lower cost and with lower CO2 emissions.

[0038] Referring here to the drawings, Figure 1 shows a general schematic process for producing SCM from an input stream containing silicates and / or aluminosilicates. All SCMs exhibit a heat release of more than 100 joules / g ("J / g"), which clearly indicates that the material is essentially pozzolanes. In the case of the control samples, the heat release is very low, indicating that the material is inert. As shown in process 5, the input material 7 and the mechanical-thermal activation aid 9 are mixed and / or pulverized 11, subjected to heat treatment 13, followed by cooling 15 and milling 17 to form SCM 19. Optionally, the cooled, thermally activated input stream may undergo a carbonation step 21.

[0039] Figure 2 shows the reactivity of SCM produced from zinc and lead tailings, nickel and copper tailings, and aggregate powder to control samples in terms of heat release.

[0040] Figure 3 shows the strength activity index of SCM prepared from various sources after 20% cement replacement in mortar mixtures according to ASTM C618.

[0041] Figure 4 shows the synergistic effect of biomass, alkali metals, and aluminosilicates during heat treatment.

[0042] Figure 5 shows photographs of SCM prepared by pelletizing the feedstock and activation aid before and after heat treatment.

[0043] Mechanical-thermal activators can reduce the vitrification and / or glass phase formation temperature of input materials, including but not limited to inert materials, tailings, crystalline aluminosilicates, silicates, construction waste, aggregates, aggregate dust, silica sand, or combinations thereof. By contacting the feed material with a mechanical-thermal activator during vitrification and / or glass phase formation, the thermal activation temperature of the input material can be reduced, inducing a chemical change that produces a reactive phase and forms a reactive material. Once activated, the reactive material can react with calcium hydroxide to form a CS-H gel via a pozzolanic reaction, and thus form a SCM. Mechanical-thermal activators can also act as network modifiers in Si-O, Al-O, and / or Al-Si-O matrices to modify the network structure and improve the reactivity of the material.

[0044] This method may improve process efficiency and accelerate the removal of hydroxyl groups from clay mineral layers by using mechanical-thermal activation aids to reduce the temperature required for dehydroxylation, modify the network structure of Si and O, Al and Si, Si, Al and O, etc. The clay minerals may be sourced from tailings waste, kaolin deposits, illite, smectite clay, mixed-layer clay, muscovite, or combinations thereof. Some sources of waste clay include, but are not limited to, oilsand tailings, coal tailings, or combinations thereof.

[0045] SCM can be prepared from input materials by thermally activating them. Activation may occur at lower temperatures by contacting the input materials with a mechanical-thermal activating agent. The temperature may be below about 1000°C, about 1000°C to about 400°C, about 950°C to about 550°C, about 900°C to about 600°C, about 850°C to about 650°C, about 800°C to about 700°C, or about 400°C. Thermal activation of the input materials may be carried out in an oxidizing environment; however, thermal activation may be carried out in a reducing environment, or an oxygen-free environment may be produced by purging with an inert gas including but not limited to CO2, H2, CO, or nitrogen and argon, helium, neon, krypton, xenon, and radon. Production of a reducing or oxygen-free environment may lower the temperature required for vitrification. Reducing conditions can be produced by contacting and / or mixing reducing agents, including but not limited to thiourea, ascorbic acid, sodium sulfite, oxalic acid, tannic acid, citric acid, or combinations thereof, with an inert gas. The inert gas and / or reducing agent may be mixed in a kiln or other container in the presence of the input material to reduce it.

[0046] Input materials containing silica and / or aluminosilicate oxides can be sources of SCM. Silica and / or aluminosilicate oxides may include, but are not limited to, waste tailings, construction waste materials, sand, or combinations thereof. Silica and / or aluminosilicate oxides can be rich sources of silicon or aluminum oxides, but may be highly crystalline in nature. However, crystalline materials do not exhibit pozzolanic or hydraulic properties and therefore do not react with calcium hydroxide in cement paste to form additional CSH gels. Consequently, they do not offer the same advantages as SCM and must be converted to SCM according to the method of the present invention.

[0047] Silicate minerals can be difficult to vitrify due to their high melting points and tendency to crystallize at high temperatures. For example, pure silica sand vitrifies at approximately 1700°C, while silicate minerals such as feldspar have a vitrification temperature of approximately 1100-1200°C. Generally, silicate minerals vitrify above 1000°C. This method may involve using mechanical-thermal activators to reduce the temperature required for vitrification, modify the network structure, and / or prevent crystal growth while cooling. Mechanical-thermal activators can lower the melting point of silicate minerals by forming a eutectic mixture with them. This mixture may have a lower melting point than the individual components, thereby allowing the material to melt and vitrify at lower temperatures. Vitrification in the presence of mechanical-thermal activators can produce SCM using globally abundant input materials, providing the superior performance characteristics needed to meet the demands of the construction industry while reducing the overall carbon footprint associated with cement production.

[0048] Clay minerals are naturally occurring minerals containing layers of metal-oxygen (e.g., aluminum-oxygen) octahedral sheets and silicon-oxygen tetrahedral sheets. These sheets can be held together by weak van der Waals forces and hydrogen bonds. Clay minerals may contain hydroxyl groups (-OH) located at the edges of the layers, which are responsible for the clay's ability to adsorb water and other polar molecules. Dehydroxylation is the process of removing hydroxyl groups from the edges of clay mineral layers. This process can be carried out by heat treatment, which involves heating the clay mineral to high temperatures (e.g., over 600°C in the case of kaolinite clay). During the heat treatment process, hydroxyl groups can decompose into water (H2O) and hydroxyl radicals (·OH), which then react with adjacent hydroxyl groups, resulting in their removal. Hydroxylated clay minerals can be amorphous and can act as a source of SCM (Sulfur-Cellulose Myrmecophilic Cellulose).

[0049] This method may involve contacting the input material with a mechanical-thermal activator. Contacting the mechanical-thermal activator with the input material may promote the vitrification of crystalline silicates and / or aluminosilicates. The mechanical-thermal activator may be an alkaline mechanical-thermal activator, but is not limited to sodium oxide, potassium oxide, lithium oxide, barium oxide and their respective sources, or combinations thereof.Mechanical-thermal activation aids include, but are not limited to, sodium oxide and its sources (including, but not limited to, sodium carbonate, sodium hydroxide, sodium chloride, sodium silicate, sodium nitrate, waste glass cullet, or combinations thereof); potassium oxide and its sources (including, but not limited to, potassium carbonate, potassium hydroxide, potassium chloride, potassium silicate, potassium nitrate, or combinations thereof); lithium oxide and its sources (including, but not limited to, lithium carbonate, lithium hydroxide, lithium chloride, lithium silicate, or combinations thereof); barium oxide and its sources (including, but not limited to, barium carbonate, barium hydroxide, barium nitrate, or combinations thereof); calcium oxide and its sources (including, but not limited to, limestone, dolomite, gypsum, calcium chloride, calcium hydroxide, or combinations thereof); and magnesium oxide and its sources (magnesite, brusite). , magnesium sulfate, or combinations thereof; aluminates (aluminum oxide, aluminum hydroxide, sodium aluminate, or combinations thereof, but not limited); borates (boric acid, boron oxide, borax, colemanite or urexite ore, or combinations thereof, but not limited); fluorides (potassium fluoride, sodium fluoride, calcium fluoride, or combinations thereof, but not limited); fluoroborates; phosphates (not limited to phosphates based on P2O5 content, including but not limited to phosphates, calcium diphosphate, sodium hexametaphosphate, or combinations thereof); or combinations thereof; iron oxides (hematite, magnetite, or combinations thereof, but not limited); biomass sources (wood, sawdust, coffee beans / ground, rice husks, or combinations thereof, but not limited) may be included.

[0050] The synergistic effect of biomass pyrolysis with alkali and / or alkaline earth metals, including but not limited to sodium, potassium, calcium, or combinations thereof, can enhance the reactivity of minerals such as SCM. Alkali or alkaline earth metal ions can migrate to the surface of aluminosilicate. Migration can occur during the heat treatment of aluminosilicate, biomass, alkali and / or alkaline earth metal sources, or combinations thereof. Mobile alkali or alkaline earth metal ions can be sequestered in aluminosilicate. Sequestering of mobile alkali or alkaline earth metal ions can occur by reaction with aluminosilicate, forming alkali aluminosilicate and / or alkaline earth aluminosilicate. Alkali aluminosilicate and / or alkaline earth aluminosilicate may include, but are not limited to, KAlSi3O8, NaAlSi3O8, KAlSiO4, NaAlSiO4, or combinations thereof. Sequestering of alkali and / or alkaline earth metal ions may occur within the crystalline structure of the aluminosilicate. The sequestration of aluminosilicate into a crystalline structure can disrupt the aluminosilicate lattice, resulting in reactive amorphous materials that act as auxiliary cement-like reagents. Furthermore, the thermal decomposition of biomass can provide additional heat input with a lower CO2 footprint. The thermal decomposition of biomass can reduce the net overall CO2 footprint of the process.

[0051] Mechanical-thermal activators can be contacted with input materials in the presence of heat and / or high temperatures. The input materials and temperatures can be selected based on the composition of the input materials. For example, in the case of kaolinite-rich clay minerals, alkalis containing sodium carbonate (but not limited to sodium carbonate) can be used at temperatures below approximately 600°C, approximately 600°C to approximately 0°C, approximately 550°C to approximately 50°C, approximately 500°C to approximately 450°C, approximately 400°C to approximately 350°C, or approximately 0°C. In the case of clays rich in illite, muscovite, and mixed smectite, alkaline mechanical-thermal activators can be combined with and / or used simultaneously with sodium, potassium, borates, aluminates, biomass, or combinations thereof to improve the vitrification process. For example, contact of alkali with borates and / or biomass can reduce the vitrification temperature and produce SCM from silicate and / or aluminosilicate-rich minerals. The mechanical-thermal activator may be co-ground in the mill to ensure dispersion; mechanical activation during the grinding stage; and / or an increase in surface area necessary for efficient activation during the heat treatment stage. The fineness of the mixture of the aluminosilicate feed stream and the mechanical-thermal activator may determine the efficiency of the heat treatment. The particle size may affect the flammability of the feed stream. The feed material and mechanical-thermal activator may be ground to sizes of less than about 200 μm, about 200 μm to about 10 μm, about 180 μm to about 20 μm, about 160 μm to about 40 μm, about 140 μm to about 60 μm, about 120 μm to about 80 μm, or about 10 μm. The feed stream after grinding can be pelletized by adding water. Pellet formation may reduce dust during heat treatment in a rotary kiln and may create a reducing environment within the pellet. A reducing environment may further enhance the reactivity of the material as SCM.

[0052] SCM may be pozzolanic and may react with calcium hydroxide (Ca(OH)2) in the presence of water to form cementitious compounds. These cementitious compounds may be reactive amorphous aluminosilicate materials that can be used for geopolymerization to form geopolymers. Geopolymers are inorganic materials that can be formed from the reaction of an aluminosilicate precursor with an alkaline solution, typically a solution of sodium hydroxide or potassium hydroxide or a silicate. Cement produced from geopolymers may have lower carbon emissions and lower temperatures than conventional Portland cement. The reaction between the aluminosilicate precursor and the alkaline solution can create a three-dimensional network of tetrahedral units linked by covalent bonds, forming a stable and durable material. Geopolymers may have properties similar to conventional cement, such as high compressive strength, low permeability, good fire resistance, or a combination thereof; they may be more environmentally friendly and chemically resistant than conventional cement.

[0053] The reactivity of SCM can be measured by contacting SCM with an alkaline solution of Ca(OH)2 and 0.5 M KOH. The resulting mixture can be cured at temperatures of at least about 45°C, about 45°C to about 55°C, about 47°C to about 53°C, 49°C to about 51°C, or about 50°C. SCM is pozzolanic and, if SCM hardens after 24 hours, is formed from a cement-like product containing calcium hydroxide.

[0054] SCM reactivity can be measured as the heat released in a model system containing calcium hydroxide, an alkaline solution of KOH, and SCM. The heat release of reactive SCM may be at least about 80 J / g, about 80 J / g to about 200 J / g, about 90 J / g to about 190 J / g, about 100 J / g to about 180 J / g, about 110 J / g to about 170 J / g, about 120 J / g to about 160 J / g, about 130 J / g to about 150 J / g, or about 200 J / g of SCM.

[0055] SCM can be used to replace cement in mortar mixtures. The replacement can be carried out as outlined in ASTM C618. The amount replaced may be at least about 10%, about 10% to about 40%, about 15% to about 35%, about 20% to about 30%, or about 40% of the mortar mixture.

[0056] The compressive strength of a material can be measured, and its Strength Activity Index ("SAI") can be determined by comparing it to a 100% cement control. According to ASTM C618, materials exhibiting an SAI greater than 75% at a 20% substitution level are classified as SCM (Structured Chemical Mass).

[0057] This method may include contacting SCM with calcium hydroxide. This method may also include contacting SCM with a base. The base may include, but is not limited to, KOH, NaOH, LiOH, CsOH, other strong bases, other ionic bases, or combinations thereof. This method may further include contacting SCM with calcium hydroxide and a base to form an activated SCM mixture. The SCM mixture may be cured at temperatures of at least about 40°C, about 40°C to about 60°C, about 42°C to about 58°C, about 44°C to about 56°C, about 46°C to about 54°C, about 48°C to about 52°C, or about 60°C. The SCM mixture may be cured for at least about 12 hours, about 12 hours to about 48 hours, about 16 hours to about 44 hours, about 20 hours to about 40 hours, or about 24 hours to about 36 hours, about 28 hours to about 32 hours, or about 48 hours.

[0058] Embodiments of the present invention provide a technology-based solution that overcomes existing problems of current state-of-the-art technology, by satisfying existing problems for reducing CO2 emissions during cement production. Embodiments of the present invention achieve significant advantages that go beyond the current state of technology, such as reduced cement production emissions using readily available source materials; and production of cement-based materials at temperatures below 1000°C. Some of the unconventional steps of embodiments of the present invention involve the addition of mechanical-thermal activators to induce vitrification of the source material to produce SCM. [Examples]

[0059] The present invention can be further described by the following non-limiting embodiments. Example 1

[0060] SCM was prepared from zinc and lead tailings. The zinc and lead tailings were pulverized with 3 wt% solid sodium carbonate and 5 wt% solid boron oxide, and heat-treated at 700°C for 1 hour. The heat-activated material was then ball-milled to prepare SCM. The prepared SCM was mixed with calcium hydroxide and KOH solution as described above and cured at 50°C for 1 day. The mixture hardened after 1 day and exhibited cementitious activity. Zinc tailings heat-treated at 700°C without mechanical-thermal activating aids did not harden after 1 day of curing. This indicates that heat treatment alone is insufficient to induce vitrification of the tailings sample. Example 2

[0061] SCM was prepared from zinc and lead tailings. The zinc and lead tailings were pulverized with 2% by weight solid sodium carbonate and 3% by weight solid boron oxide, and heat-treated at 700°C for 1 hour. The heat-activated material was then ball-milled to prepare SCM. The prepared SCM was mixed with calcium hydroxide and KOH solution as described above and cured at 50°C for 1 day. The mixture hardened after 1 day and exhibited cementitious activity. Example 3

[0062] SCM was prepared from nickel and copper tailings. Nickel and copper tailings were pulverized with 3 wt% solid sodium carbonate and 5 wt% solid boron oxide, and heat-treated at 700°C for 1 hour. The heat-activated material was then ball-milled to prepare SCM. The prepared SCM was mixed with calcium hydroxide and KOH solution as described above and cured at 50°C for 1 day. The mixture hardened after 1 day and showed cementitious activity. Nickel and copper tailings heat-treated at 700°C without mechanical-thermal activating aids did not harden after 1 day of curing. This indicates that heat treatment alone is not sufficient to induce vitrification of tailings samples. Example 4

[0063] SCM was prepared from nickel and copper tailings. The nickel and copper tailings were pulverized with 2 wt% solid sodium carbonate and 3 wt% solid boron oxide, and heat-treated at 700°C for 1 hour. The heat-activated material was then ball-milled to prepare SCM. The prepared SCM was mixed with calcium hydroxide and KOH solution as described above and cured at 50°C for 1 day. The mixture hardened after 1 day and exhibited cementitious activity. Example 5

[0064] SCM was prepared from nickel and copper tailings. The nickel and copper tailings were pulverized with 7 wt% solid sodium carbonate and 3 wt% solid boric acid, and heat-treated at 700°C for 1 hour. The heat-activated material was then ball-milled to prepare SCM. The prepared SCM was mixed with calcium hydroxide and KOH solution as described above and cured at 50°C for 1 day. The mixture hardened after 1 day and exhibited cementitious activity. Example 6

[0065] SCM was prepared from copper tailings. Copper tailings were pulverized with 3 wt% solid sodium carbonate and 5 wt% solid boron oxide, and heat-treated at 700°C for 1 hour. The heat-activated material was then ball-milled to prepare SCM. The prepared SCM was mixed with calcium hydroxide and KOH solution as described above and cured at 50°C for 1 day. The mixture hardened after 1 day and showed cementitious activity. Copper tailings heat-treated at 700°C without mechanical-thermal activating aids did not harden after 1 day of curing. This indicates that heat treatment alone is not sufficient to induce vitrification of the tailings sample. Example 7

[0066] SCM was prepared from aggregate powder. The aggregate powder was ground with 3 wt% solid sodium carbonate and 5 wt% solid boron oxide and heat-treated at 700°C for 1 hour. The heat-activated material was then ball-milled to prepare SCM. The prepared SCM was mixed with calcium hydroxide and KOH solution as described above and cured at 50°C for 1 day. The mixture hardened after 1 day and showed cementitious activity. Aggregate powder heat-treated at 700°C without mechanical-thermal activating aids did not harden after 1 day of curing. This indicates that heat treatment alone is not sufficient to induce vitrification of aggregate powder. Example 8

[0067] SCM was prepared from muscovite and / or illite. Muscovite and / or illite-rich clay was pulverized with 2 wt% solid sodium carbonate and 3 wt% solid boron oxide and heat-treated at 700°C for 1 hour. The heat-activated material was then ball-milled to prepare SCM. The prepared SCM was mixed with calcium hydroxide and KOH solution as described above and cured at 50°C for 1 day. The mixture hardened after 1 day and showed cementitious activity. Clay heat-treated at 700°C without mechanical-thermal activating aids did not harden after 1 day of curing. This indicates that heat treatment alone cannot induce vitrification of illite and / or muscovite clay. Example 9

[0068] SCM was prepared from muscovite and / or illite. Muscovite and / or illite-rich clay was ground with 2 wt% solid sodium carbonate and 3 wt% solid borax and heat-treated at 700°C for 1 hour. The heat-activated material was then ball-milled to prepare SCM. The prepared SCM was mixed with calcium hydroxide and KOH solution as described above and cured at 50°C for 1 day. The mixture hardened after 1 day and showed cementitious activity. Clay heat-treated at 700°C without mechanical-thermal activating aids did not harden after 1 day of curing. This indicates that heat treatment alone cannot induce vitrification of illite and / or muscovite clay. Example 10

[0069] SCM was prepared from muscovite and / or illite. Muscovite and / or illite-rich clay was pulverized with 5% by weight of solid sodium carbonate and heat-treated at 700°C for 1 hour. The heat-activated material was then ball-milled to prepare SCM. The prepared SCM was mixed with calcium hydroxide and KOH solution as described above and cured at 50°C for 1 day. The mixture hardened after 1 day and showed cementitious activity. Clay heat-treated at 700°C without mechanical-thermal activating aids did not harden after 1 day of curing. This indicates that heat treatment alone cannot induce vitrification of illite and / or muscovite clay. Example 11

[0070] SCM was prepared from recycled cement paste. The recycled cement paste was pulverized with 2% by weight solid sodium carbonate and 3% by weight solid boron oxide, and heat-treated at 600°C for 1 hour. The heat-activated material was then ball-milled to prepare SCM. The prepared SCM was mixed with calcium hydroxide and KOH solution as described above and cured at 50°C for 1 day. The mixture hardened after 1 day and showed cement-like activity. Recycled cement paste treated at 700°C without mechanical-thermal activating aids did not harden after 1 day of curing. This indicates that heat treatment alone is not sufficient to induce vitrification of recycled cement paste. Example 12

[0071] SCM was prepared from recycled cement paste. The recycled cement paste was ground with 2% by weight solid sodium carbonate and 3% by weight solid borax, and heat-treated at 700°C for 1 hour. The heat-activated material was then ball-milled to prepare SCM. The prepared SCM was mixed with calcium hydroxide and KOH solution as described above and cured at 50°C for 1 day. The mixture hardened after 1 day and showed cement-like activity. Recycled cement paste treated at 700°C without mechanical-thermal activating aids did not harden after 1 day of curing. This indicates that heat treatment alone is not sufficient to induce vitrification of recycled cement paste. Example 13

[0072] SCM was prepared from recycled cement paste. The recycled cement paste was ground with 2 wt% solid sodium carbonate and 2 wt% solid aluminum hydroxide and heat-treated at 700°C for 1 hour. The heat-activated material was then ball-milled to prepare SCM. The prepared SCM was mixed with calcium hydroxide and KOH solution as described above and cured at 50°C for 1 day. The mixture hardened after 1 day and showed cement-like activity. Recycled cement paste treated at 700°C without mechanical-thermal activating aids did not harden after 1 day of curing. This indicates that heat treatment alone is not sufficient to induce vitrification of recycled cement paste. Example 14

[0073] SCM was prepared from recycled cement paste. The recycled cement paste was pulverized with 5% by weight of barium carbonate and heat-treated at 700°C for 1 hour. The heat-activated material was then ball-milled to prepare SCM. The prepared SCM was mixed with calcium hydroxide and KOH solution as described above and cured at 50°C for 1 day. The mixture hardened after 1 day and showed cement-like activity. Recycled cement paste treated at 700°C without mechanical-thermal activating aids did not harden after 1 day of curing. This indicates that heat treatment alone is not sufficient to induce vitrification of recycled cement paste. Example 15

[0074] SCM was prepared from recycled cement paste. The recycled cement paste was pulverized with 5% by weight of sodium carbonate and heat-treated at 700°C for 1 hour. The heat-activated material was then ball-milled to prepare SCM. The prepared SCM was mixed with calcium hydroxide and KOH solution as described above and cured at 50°C for 1 day. The mixture hardened after 1 day and showed cement-like activity. Recycled cement paste treated at 700°C without mechanical-thermal activating aids did not harden after 1 day of curing. This indicates that heat treatment alone is not sufficient to induce vitrification of recycled cement paste. Example 16

[0075] SCM was prepared from recycled concrete aggregate. The recycled concrete aggregate was crushed with 3 wt% solid sodium carbonate and 5 wt% solid aluminum hydroxide and heat-treated at 700°C for 1 hour. The heat-activated material was then ball-milled to prepare SCM. The prepared SCM was mixed with calcium hydroxide and KOH solution as described above and cured at 50°C for 1 day. The mixture hardened after 1 day and showed cementitious activity. Recycled concrete aggregate treated at 800°C without mechanical-thermal activating aids did not harden after 1 day of curing. This indicates that heat treatment alone is not sufficient to induce vitrification of recycled concrete aggregate. Example 17

[0076] SCM was prepared from recycled concrete aggregate. The recycled concrete aggregate was crushed with 3 wt% solid sodium carbonate and 5 wt% solid boron oxide, and heat-treated at 800°C for 1 hour. The heat-activated material was then ball-milled to prepare SCM. The prepared SCM was mixed with calcium hydroxide and KOH solution as described above and cured at 50°C for 1 day. The mixture hardened after 1 day and showed cementitious activity. Recycled concrete aggregate treated at 800°C without mechanical-thermal activating aids did not harden after 1 day of curing. This indicates that heat treatment alone is not sufficient to induce vitrification of recycled concrete aggregate. Example 18

[0077] SCM was prepared from recycled concrete aggregate. The recycled concrete aggregate was pulverized with 5% by weight solid sodium carbonate and 5% by weight solid boric acid, and heat-treated at 800°C for 1 hour. The heat-activated material was then ball-milled to prepare SCM. The prepared SCM was mixed with calcium hydroxide and KOH solution as described above and cured at 50°C for 1 day. The mixture hardened after 1 day and showed cementitious activity. Recycled concrete aggregate treated at 800°C without mechanical-thermal activating aids did not harden after 1 day of curing. This indicates that heat treatment alone is not sufficient to induce vitrification of recycled concrete aggregate. Example 19

[0078] SCM was prepared from recycled concrete aggregate. The recycled concrete aggregate was pulverized with 10% by weight solid calcium oxide and 3% by weight solid boric acid, and heat-treated at 800°C for 1 hour. The heat-activated material was then ball-milled to prepare SCM. The prepared SCM was mixed with calcium hydroxide and KOH solution as described above and cured at 50°C for 1 day. The mixture hardened after 1 day and showed cementitious activity. Recycled concrete aggregate treated at 800°C without mechanical-thermal activating aids did not harden after 1 day of curing. This indicates that heat treatment alone is not sufficient to induce vitrification of recycled concrete aggregate. Example 20

[0079] SCM was prepared from recycled concrete aggregate. The recycled concrete aggregate was crushed with 10% by weight of solid sodium carbonate and heat-treated at 700°C for 1 hour. Then, the heat-activated material was ball-milled to prepare SCM. The prepared SCM was mixed with calcium hydroxide and KOH solution as described above and cured at 50°C for 1 day. The mixture hardened after 1 day and showed cementitious activity. Recycled concrete aggregate treated at 700°C without mechanical-thermal activating aids did not harden after 1 day of curing. This indicates that heat treatment alone cannot induce vitrification of recycled concrete. Example 21

[0080] SCM was prepared from recycled concrete aggregate. The recycled concrete aggregate was crushed with 10% by weight of solid sodium carbonate and heat-treated at 700°C for 1 hour. The material was then dispersed in water in a 3:2 (solid:liquid) ratio containing 0.1% polyacrylate dispersant, and the slurry was carbonated for 1 hour by bubbling CO2 into it. The carbonated slurry was then filtered and dried. The carbon dioxide uptake of the material, measured by TGA, was 6%. The carbonation step can also be performed by regenerating sodium carbonate. Furthermore, the presence of sodium carbonate catalyzes the reaction rate of carbon sequestration. The carbonated thermally activated material was then ball-milled to prepare SCM. The prepared SCM was mixed with calcium hydroxide and KOH solution as described above and cured at 50°C for 1 day. The mixture hardened after 1 day and showed cementitious activity. Recycled concrete aggregate treated at 700°C without mechanical-thermal activating aids did not harden after 1 day of curing. This demonstrated that heat treatment alone cannot cause vitrification of recycled concrete. Example 22

[0081] SCM was prepared from silica sand. Silica sand was pulverized with 3 wt% solid sodium carbonate and 5 wt% solid boron oxide, and then heat-treated at 700°C and 800°C for 1 hour. The heat-activated material was then ball-milled to prepare SCM. The prepared SCM was mixed with calcium hydroxide and KOH solution as described above and cured at 50°C for 1 day. The mixture hardened after 1 day and exhibited cementitious activity. Silica sand treated at 800°C without mechanical-thermal activation aids did not harden after 1 day of curing. This indicates that heat treatment alone is insufficient to induce vitrification of recycled concrete aggregate. Example 23

[0082] SCM was prepared from kaolinite clay. Kaolinite clay from Georgia, Spain, and Turkey was ground with 2% by weight of solid potassium difluoride and heat-treated at 450°C for 1 hour. The heat-activated material was then ball-milled to prepare SCM. The prepared SCM was mixed with calcium hydroxide and KOH solution as described above and cured at 50°C for 1 day. All samples hardened strongly after 3 hours and showed cementitious activity. Kaolinite clay without mechanical-thermal activating aids at 450°C showed some hardness after 1 day but did not show strong bonding. This indicates that the use of mechanical-thermal activating aids improves the degree of dehydroxylation. Example 24

[0083] SCM was prepared from kaolinite-rich clay. The kaolinite-rich clay was pulverized with 3 wt% solid sodium silicate and 0.25% ascorbic acid as a reducing agent, and then heat-treated at 500°C for 1 hour in a CO2 environment. The heat-activated material was then ball-milled to prepare SCM. The prepared SCM was mixed with calcium hydroxide and KOH solution as described above and cured at 50°C for 1 day. All samples hardened strongly after 3 hours and showed cementitious activity. Kaolinite clay without mechanical-thermal activation aids at 500°C showed some hardness after 1 day but did not exhibit strong bonding. This indicates that the use of mechanical-thermal activation aids improves the degree of dehydroxylation. Example 25

[0084] SCM was prepared from mature fine tailings. Mature fine tailings from oil sand were ground with 3 wt% solid sodium carbonate and heat-treated at 450°C, 500°C, and 550°C for 1 hour, respectively. The heat-activated material was then ball-milled to prepare SCM. The prepared SCM was mixed with calcium hydroxide and KOH solutions as described above and cured at 50°C for 1 day. All samples hardened after 1 day and showed cementitious activity. Oil sand clay without mechanical-thermal activators at 550°C showed some hardness after 1 day but did not show strong bonding. This indicates that the use of mechanical-thermal activators improves the degree of dehydroxylation. Example 26

[0085] SCM was prepared from bedding sand. The bedding sand (a mixture of sand and clay) was crushed with 3 wt% solid sodium carbonate and 5 wt% solid boron oxide, and then heat-treated at 800°C for 1 hour. The heat-activated material was then ball-milled to prepare SCM. The prepared SCM was mixed with calcium hydroxide and KOH solution as described above and cured at 50°C for 1 day. The mixture hardened after 1 day and exhibited cementitious activity. Silica sand treated at 800°C without mechanical-thermal activation aids did not harden after 1 day of curing. This indicates that heat treatment alone is insufficient to induce vitrification of recycled concrete aggregate. Example 27

[0086] The prepared SCM was crushed and / or milled in a CO2 atmosphere for mineral carbonation. Specifically, recycled concrete aggregate was crushed with 10 wt% solid calcium oxide and 3% boric acid and heat-treated at 800°C for 1 hour. The thermally activated recycled concrete aggregate was then ball-milled in a CO2 atmosphere (10 psi pressure) by purging to prepare SCM and capture CO2. The prepared SCM was mixed with calcium hydroxide and KOH solution as described above and hardened at 50°C for 1 day. The mixture hardened after 1 day and showed cementitious activity. Example 28

[0087] SCM was prepared from nickel and copper tailings. The nickel and copper tailings were crushed with 10% by weight of solid sodium carbonate and heat-treated at 700°C for 1 hour. The heat-activated material was then ball-milled to prepare SCM. The prepared SCM was mixed with calcium hydroxide and KOH solution as described above and cured at 50°C for 1 day. The mixture hardened after 1 day and exhibited cementitious activity. Example 29

[0088] SCM was prepared from oil shale ash. The oil shale ash was pulverized with 5% by weight of solid barium carbonate and heat-treated at 500°C for 1 hour. The heat-activated material was then ball-milled to prepare SCM. The prepared SCM was mixed with calcium hydroxide and KOH solution as described above and cured at 50°C for 1 day. The mixture hardened after 1 day and exhibited cementitious activity. Example 30

[0089] SCM was prepared from bottom ash. The bottom ash was pulverized with 3% by weight of solid sodium carbonate and heat-treated at 400°C for 1 hour. The heat-activated material was carbonated with 0.1% polyacrylate dispersant in a 7:3 solid / liquid ratio for 1 hour and dried. Furthermore, the presence of sodium carbonate catalyzes the carbon sequestration reaction rate. The dried material was then ball-milled to prepare SCM. The prepared SCM was mixed with calcium hydroxide and KOH solution as described above and cured at 50°C for 1 day. The mixture hardened after 1 day and exhibited cementitious activity. Example 31

[0090] SCM was prepared from recycled concrete aggregate. The recycled concrete aggregate was crushed with 3 wt% solid sodium carbonate and 5 wt% sawdust as a biomass source, and heat-treated at 700°C for 1 hour. The heat-activated material was then ball-milled to prepare SCM. The prepared SCM was mixed with calcium hydroxide and KOH solution as described above and cured at 50°C for 1 day. The mixture hardened after 1 day and showed cementitious activity. Recycled concrete aggregate treated at 700°C without mechanical-thermal activation aids did not harden after 1 day of curing. This indicates that heat treatment alone is not sufficient to induce vitrification of recycled concrete aggregate. Example 32

[0091] SCM was prepared from recycled concrete aggregate. The recycled concrete aggregate was crushed with 3 wt% solid sodium carbonate and 5 wt% sawdust as a biomass source. The material was then pelletized by spraying water and using a baffle mixer. The pelletized feed was then heat-treated at 700°C for 1 hour. The heat-activated material was then ball-milled to prepare SCM. The prepared SCM was mixed with calcium hydroxide and KOH solution as described above and cured at 50°C for 1 day. The mixture hardened after 1 day and showed cementitious activity. Recycled concrete aggregate treated at 700°C without mechanical-thermal activation aids did not harden after 1 day of curing. This indicates that heat treatment alone is not sufficient to induce vitrification of recycled concrete aggregate. Example 33

[0092] SCM was prepared from recycled concrete pulverized material. Recycled concrete aggregate was crushed with 3 wt% solid sodium carbonate and 5 wt% sawdust as a biomass source, and heat-treated at 700°C at a 1.5° incline and 1 RPM in an electrically heated rotary kiln with a length of 1.7 m (heating zone 0.9 m) and a diameter of 0.1 m, with a residence time of 45 minutes in the hot zone. The heat-activated material was then pulverized in a pulverizer to produce a 300-mesh product as SCM. The prepared SCM was mixed with calcium hydroxide and KOH solution as described above and cured at 50°C for 1 day. The mixture hardened after 1 day and showed cementitious activity. Recycled concrete aggregate treated at 700°C without mechanical-thermal activation aids did not harden after 1 day of curing. This indicates that heat treatment alone is not sufficient to induce vitrification of recycled concrete aggregate. Example 34

[0093] SCM was prepared from kaolinite-rich clay. The clay was crushed with 3 wt% solid sodium carbonate and 5 wt% sawdust as a biomass source, and then heat-treated at 550°C for 1 hour. The heat-activated material was then ball-milled to prepare SCM. Mortar blocks were prepared using the activated clay. The SAI after 28 days was 107%. Similarly, to compare with conventional heat-treated kaolinite clay, a control clay sample was fired at 750°C for 1 hour. The SAI of the prepared mortar after 18 days was 106%. This indicates that kaolinite clay can be activated at lower temperatures by the addition of sodium carbonate and sawdust.

[0094] The above-described examples can be repeated with similar success by substituting those used in the above-described examples with the general or specifically described reactants and / or operating conditions of the present invention.

[0095] In the specification and claims, “about” or “approximately” means within 20 percent of the cited figure. The terms “a,” “an,” “the,” and “said” mean “one or more” unless the context specifically indicates otherwise.

[0096] Although the present invention has been described in detail with particular reference to these embodiments, other embodiments can achieve the same results. Variations and modifications of the present invention will be obvious to those skilled in the art, and all such modifications and equivalents are intended to be covered in the appended claims. All of the entire disclosures of all references, applications, patents and publications cited above are incorporated herein by reference.

Claims

1. A method for producing auxiliary cement-based materials, Bringing the input flow containing the grid into contact with a mechanical-thermal activation aid; The aforementioned input flow is heat-treated to form a heat-treated input flow; Isolating ions; Destroying the grid of the input flow; and A method comprising cooling the heat-treated feed stream.

2. The method according to claim 1, further comprising an oxidizing environment.

3. The method according to claim 1, further comprising a reducing environment.

4. The method according to claim 1, further comprising an inert environment.

5. The method according to claim 1, further comprising carbonating the heat-treated feed stream.

6. The method according to claim 1, further comprising co-pulverizing the input flow and the mechanical-thermal activation aid.

7. The method according to claim 1, further comprising pelletizing the input flow and the mechanical-thermal activation aid.

8. The method according to claim 1, further comprising milling the heat-treated feed stream.

9. The method according to claim 1, further comprising reducing the vitrification temperature.

10. The method according to claim 1, wherein the mechanical-thermal activation aid contains biomass.

11. The method according to claim 10, further comprising thermally decomposing the biomass.

12. The method according to claim 1, wherein the input flow contains an aluminosilicate.

13. The method according to claim 1, wherein the ion includes an alkali metal ion.

14. The method according to claim 1, wherein the ions include alkaline earth metal ions.

15. The method according to claim 12, further comprising contacting the aluminosilicate with alkali metal ions.

16. The method according to claim 12, further comprising contacting the aluminosilicate with an alkaline earth metal ion.

17. The method according to claim 1, wherein the heat treatment comprises heating the input flow and the mechanical-thermal activation aid to a temperature of about 400°C to about 1000°C.

18. The method according to claim 1, wherein the input flow includes recycled concrete aggregate.

19. The method according to claim 1, wherein the input flow contains clay rich in kaolinite.

20. The method according to claim 1, wherein the input flow contains recycled concrete fine powder.

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