JP2011527664A - Production of carbonate-containing compositions from metal-containing silicate materials - Google Patents

Abstract

A method for producing a carbonate-containing composition comprising a silicon-based material (eg, a pozzolanic material) from a carbon dioxide source, a divalent cation-containing solution, and a proton scavenger source is provided. In this way, the divalent cation of the divalent cation-containing solution is provided by digestion of the metal-containing silicate material. Also provided are methods of making carbonate-containing compositions that contain little or no silicon-based material. In such a method, a silicon-based material (eg, silica, unreacted or undigested silicate, aluminosilicate, etc.) is separated and treated separately from the carbonate-containing composition. The silicon-based material and the carbonate-containing material are blended at a later stage to produce a pozzolanic material, and the pozzolanic material may be further processed, eg, blended with Portland cement.

Description

This application claims priority to US Provisional Patent Application No. 61 / 079,790, filed Jul. 10, 2008. This application also includes US patent application Ser. No. 12 / 486,692 filed Jun. 17, 2009 and US Pat. Application filed Dec. 24, 2008, each of which is incorporated herein by reference. This is a continuation-in-part of application No. 12 / 344,019.

  Concrete is the most widely used engineering material in the world. The current global consumption of concrete is estimated to be 11 billion metric tons / year (Concrete, Microstructure, Properties and Materials (2006, McGraw-Hill)). Concrete is a term that refers to a composite material of a binding medium in which aggregate particles or fragments are embedded. In most construction concrete currently in use, the binding medium is formed from a mixture of hydraulic cement and water.

Hydraulic cement is a composition that hardens and hardens after combination with water. After hardening, the hydraulic cement retains strength and stability even in water. An important requirement for this property is that the hydrate formed from the hydration of the components of the cement is essentially insoluble in water. The cement may be used alone or in combination with both coarse and fine aggregates, in which case the composition is referred to as concrete or mortar, respectively. Most hydraulic cements used today are based on Portland cement. Portland cement is produced primarily from limestone, certain clay minerals, and gypsum in a high temperature process that releases carbon dioxide (CO ₂ ) and chemically combines the main raw materials into new compounds.

  Carbon dioxide emissions from other industrial processes such as Portland cement production and fossil fuel-based power generation (eg, coal-fired power plants) are responsible for the phenomenon of global warming. Increasing the atmospheric concentration of carbon dioxide and other greenhouse gases facilitates greater storage of heat in the atmosphere resulting in increased surface temperature and rapid climate change. In addition, rising atmospheric carbon dioxide levels are expected to further acidify the world's oceans due to carbon dioxide dissolution and carbonation formation. The effects of climate change and ocean acidification are economically expensive and environmentally hazardous if not handled in a timely manner. Sequestration and avoidance of carbon dioxide from various anthropogenic processes offers the potential to reduce the risk of climate change.

  The invention disclosed herein provides carbon dioxide sequestration and avoidance by methods and systems for producing carbonate-containing compositions from metal-containing silicate materials, which compositions may be used in concrete. Good.

Digesting the metal-containing silicate material with an aqueous solution to produce a divalent cation and a material comprising SiO ₂ ; reacting the divalent cation with dissolved carbon dioxide to produce a precipitate; And a step of drying. In such a method, the precipitate may be dried to form a fine powder with a consistent particle size distribution. The method is a step of comminuting the metal-containing silicate material prior to digestion of the metal-containing silicate material, wherein the metal-containing silicate material includes rocks or minerals, and the mineral is orthosilicate, inosilicate, phyllosilicate, and It may further include a step including tectosilicate. Orthosilicate minerals include olivine group minerals, and phyllosilicate minerals include serpentine group minerals. In some embodiments, digesting the metal-containing silicate material includes digestion with an acid to produce an acidic solution comprising a divalent cation and a material comprising SiO ₂ . Acids are HF, HCl, HBr, HI, H ₂ SO ₄ , HNO ₃ , H ₃ PO ₄ , chromic acid, H ₂ CO ₃ , acetic acid, citric acid, formic acid, gluconic acid, lactic acid, oxalic acid, tartaric acid, ascorbine It may be selected from the group consisting of acids and meldrum acids. In some embodiments, the acid is HCl. After digestion, the acidic solution may be contacted with a proton scavenger. In some embodiments, the acidic solution is made basic by contact with a proton scavenger, which proton scavenger is selected from the group consisting of NaOH, KOH, Ca (OH) ₂ , and Mg (OH) _2. It may be a hydroxide. In some embodiments, the hydroxide is NaOH. In some embodiments, the step of digesting the material comprising metal silicates, including digestion with proton-removing agents to produce a basic solution containing a material containing a divalent cation and SiO _2. In some embodiments, digestion provides divalent cations including alkaline earth metal cations. In some embodiments, the alkaline earth metal cation comprises Ca ²⁺ , Mg ²⁺ , or a combination thereof. The method may further comprise the step of isolating the precipitate. In some embodiments, the precipitate is isolated from the basic solution in a liquid-solid separation apparatus, which operates in a continuous, semi-batch, or batch process. In some embodiments, the isolation of the precipitate is a continuous process. The precipitate may also be dried in a spray dryer in some embodiments to provide a fine powder. In some embodiments, at least 70% of the fine powder falls in the range of ± 50 microns of a given average diameter, where the given average particle size is 5 to 500 microns. In some embodiments, at least 70% of the fine powder falls in the range of ± 50 microns of a given average diameter, where the given average particle size is 50-250 microns. In some embodiments, at least 70% of the fine powder falls in the range of ± 50 microns of a given average diameter, where the given average particle size is 100-200 microns. The precipitate may include a pozzolanic material in some embodiments; however, in some embodiments, the method further includes producing a pozzolanic material from the precipitate. And in some embodiments, the method further comprises blending the pozzolanic material with cement.

Divalent to produce a precipitate; step and separating the material containing SiO ₂ from the aqueous solution; step and digesting the material comprising metal silicates with an aqueous solution to provide a material comprising a divalent cation and SiO ₂ Reacting cations with dissolved carbon dioxide is also provided. The method is a step of comminuting the metal-containing silicate material prior to digestion of the metal-containing silicate material, wherein the metal-containing silicate material includes rocks or minerals, and the mineral is orthosilicate, inosilicate, phyllosilicate, and It may further include a step including tectosilicate. Orthosilicate minerals include olivine group minerals, and phyllosilicate minerals include serpentine group minerals. In some embodiments, digesting the metal-containing silicate material includes digestion with an acid to produce an acidic solution comprising a divalent cation and a material comprising SiO ₂ . Acids are HF, HCl, HBr, HI, H ₂ SO ₄ , HNO ₃ , H ₃ PO ₄ , chromic acid, H ₂ CO ₃ , acetic acid, citric acid, formic acid, gluconic acid, lactic acid, oxalic acid, tartaric acid, ascorbine It may be selected from the group consisting of acids and meldrum acids. In some embodiments, the acid is HCl. After digestion, the acidic solution is contacted with a proton scavenger. In some embodiments, the acidic solution is made basic by contact with a proton scavenger, which proton scavenger is selected from the group consisting of NaOH, KOH, Ca (OH) ₂ , and Mg (OH) _2. It may be a hydroxide. In some embodiments, the hydroxide is NaOH. In some embodiments, the step of digesting the material comprising metal silicates, including digestion with proton-removing agents to produce a basic solution containing a material containing a divalent cation and SiO _2. In some embodiments, digestion provides divalent cations including alkaline earth metal cations. In some embodiments, the alkaline earth metal cation comprises Ca ²⁺ , Mg ²⁺ , or a combination thereof. The step of separating the material comprising SiO ₂ from the aqueous solution may include separation in a first liquid-solid separation device, wherein the separation in the first liquid-solid separation device is a continuous, semi-batch, or batch process. It is. The method may further comprise isolating the precipitate after reacting the divalent cation with dissolved carbon dioxide. In such a method, the precipitate may be isolated from the basic solution in a second liquid-solid separator, where the isolation of the precipitate in the second liquid-solid separator is continuous, semi-batch, Or a batch process. In some embodiments, the isolation of the precipitate is a continuous process. The material containing the separated SiO ₂ and the isolated precipitate may be combined without drying to produce a pozzolanic material. One of the separated SiO ₂ containing material or isolated precipitate may also be dried prior to combining to form a pozzolanic material. In addition, each of the separated SiO ₂ containing material and the isolated precipitate may be dried before being combined to form a pozzolanic material. Thus, the precipitate may be dried in a spray drier to produce a material containing SiO _2, or precipitate and spray drying the material both materials including SiO _2,. In some embodiments, at least 70% of the spray-dried material falls within ± 50 microns of a given average particle size, where the given average particle size is between 5 and 500 microns. In some embodiments, at least 70% of the spray-dried material falls in the range of ± 50 microns of a given average particle size, where the given average particle size is 50-250 microns. In some embodiments, at least 70% of the spray-dried material falls in the range of ± 50 microns for a given average particle size, where the given average particle size is between 100 and 200 microns. The method may further comprise fortifying the pozzolanic material with volcanic ash, fly ash, silica fume, highly reactive metakaolin, or ground granulated blast furnace slag. The method may further comprise blending the pozzolanic material with the cement.

  Compositions made by any of the foregoing methods are also provided. Compositions comprising synthetic carbonates, silicon-based materials, and synthetic iron-based materials are also provided. The synthetic carbonate may include magnesium carbonate selected from the group consisting of alunite, magnesite, hydromagnesite, Neskehonite, and Lancefrite. In some embodiments, the synthetic carbonate comprises nesquehonite. The composition may comprise up to 35% silicon-based material, including silica, such as amorphous silica. The iron-based material may include iron chloride or iron carbonate. The synthetic carbonate may further include calcium carbonate selected from the group consisting of calcite, aragonite, and vaterite. In some embodiments, the composition further comprises cement, wherein 80% or less of the composition comprises cement and 55% or less of the composition comprises a silicon-based material. Some of the compositions constitute construction materials, but some are suitable for use in construction materials. Such construction materials include, but are not limited to, cement, aggregate, cementitious material, or supplemental cementitious material.

  A system comprising: a processing apparatus for treating a metal-containing silicate material; a precipitation reactor for precipitating a precipitate; and a liquid-solid separator for separating the precipitate from the precipitation reaction mixture. Is also provided that is operably connected to both the processing unit and the liquid-solid separator. In such a system, the processing apparatus includes a size reduction unit for comminuting the metal-containing silicate material, including a ball mill or a jet mill. The processing apparatus may further include a digester for digesting the metal-containing silicate material, the digester being arranged to receive the metal-containing silicate material having a reduced size. The digester may be further arranged to accept an acid from the acid source, a proton remover from the proton source, or a combination thereof. The precipitation reactor of such a system may be configured to receive a digested metal-containing silicate material. In addition, the precipitation reactor may be further configured to accept carbon dioxide from an industrial source of carbon dioxide. The liquid-solid separator of such a system may be configured to accept the precipitation reaction mixture from the precipitation reactor. The liquid-solid separator may be further arranged to separate the precipitate from the precipitation reaction mixture. The system may further include a dryer for producing a dry precipitate, the dryer being a spray dryer configured to receive the slurry containing the precipitate from the liquid-solid separator. Also good. In some embodiments, the spray dryer is such that at least 70% of the dried precipitate falls within a range of ± 50 microns of a given average particle size, where the given average particle size is 5 to 500 microns. Arranged to produce a dry precipitate. In some embodiments, the spray dryer is such that at least 70% of the dried precipitate falls within ± 50 microns of a given average particle size, where the given average particle size is 50-250 microns. Arranged to produce a dry precipitate. In some embodiments, the spray dryer is such that at least 70% of the dried precipitate falls in the range of ± 50 microns of a given average diameter, where the given average particle size is 100-200 microns. Arranged to produce a dry precipitate. The spray dryer may also be further configured to utilize waste heat from industrial carbon dioxide sources, including flue gas from coal-fired power plants. The spray dryer may be further arranged to provide a heat depleted industrial carbon dioxide source to the precipitation reactor.

In addition, systems and methods for manufacturing pozzolanic materials are provided. Embodiments of the present invention include the steps of precipitating a carbonate-containing precipitate comprising SiO ₂ from a divalent cation-containing solution and producing a pozzolanic material from the resulting precipitate. Contacting a mafic mineral (eg, olivine) with a divalent cation-containing solution (eg, seawater) and adding a proton scavenger to the divalent cation-containing solution to produce a carbonate-containing precipitate; A pozzolanic material may be produced from the resulting carbonate-containing precipitate containing SiO ₂ . SiO ₂ may be at least partially amorphous and may also include a gel in various embodiments. In some embodiments, the divalent cation-containing solution is, for example, a gas stream comprising CO ₂ in the divalent cation-containing solution before or while contacting the mafic mineral with the divalent cation-containing solution. It may be acidified by bubbling. The gas stream may include exhaust gas such as flue gas. In some embodiments, the exhaust gas is used in a spray dryer before being used to acidify the divalent cation-containing solution. The same spray dryer may be used to dry the carbonate-containing precipitate. In some embodiments, the method further comprises adding a carbonate promoter, such as a transition metal such as iron, to the divalent cation-containing solution to produce a carbonate-containing precipitate. The carbonate containing precipitate may comprise calcium carbonate, magnesium carbonate, calcium magnesium carbonate, or a mixture thereof. Production of the pozzolanic material may include drying a mixture of precipitates comprising carbonate and SiO ₂ .

  A system for producing a pozzolanic material is also provided, which system is configured to receive a divalent cation-containing solution into its bottom portion; a mafic mineral-containing vertical column; A first reaction vessel configured to receive a divalent cation-containing solution from a top portion of the first liquid-solid separator configured to receive a first precipitate from the first reaction vessel; and A spray dryer configured for receiving the first precipitate from the first liquid-solid separator may be included. The reaction vessel may be further configured to receive a carbonate promoter in some embodiments. The spray dryer may also be configured to receive exhaust gas and the vertical column may be configured to receive exhaust gas from the spray dryer. In some embodiments, a second liquid-solid separator is in fluid communication between the top portion of the vertical column and the first reaction vessel. In some of these embodiments, the system may further include a precipitate washer configured to receive the second precipitate from the second liquid-solid separator. The system may further include a second reaction vessel configured to receive the divalent cation-containing solution from the first liquid-solid separator, and in some of these embodiments, the second reaction vessel to the second reaction vessel. It may further include a second liquid-solid separator configured to receive the precipitate.

  The novel features of the invention are set forth with particularity in the appended claims. A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the invention are utilized, and the accompanying drawings of which:

A method for producing a precipitate from a metal-containing silicate material is illustrated. FIG. 3 shows a flowchart diagram of an exemplary method for manufacturing a pozzolanic material, according to an embodiment of the present invention. 1 illustrates a system configured to produce a precipitate from a metal-containing silicate material. 1 shows a schematic diagram of an exemplary manufacturing system for pozzolanic material, according to an embodiment of the present invention. FIG. 3 shows any additional schematics to the system shown in FIG. 2 according to an embodiment of the present invention. FIG. 3 shows any additional schematics to the system shown in FIG. 2 according to an embodiment of the present invention. FIG. 3 shows any additional schematics to the system shown in FIG. 2 according to an embodiment of the present invention. FIG. 4 provides an SEM image of the precipitate of Example 4 at 2.5k (left) and 4.0k magnification showing rod-like morphology (Neskehonite) and amorphous silica gel. FIG. 4 provides XRD diffractograms for the precipitate of Example 4 (top diffractogram), rock salt (intermediate diffractogram), and Neskehonite (bottom diffractogram). 2 provides a TGA thermogram of the precipitate of Example 4. 7 provides a graph of particle size distribution for Type II / V Portland cement and Portland cement blended with the precipitate of Example 5.

  Before the present invention is described in more detail, it is to be understood that the present invention is not limited to the specific embodiments described and, of course, may vary. The terminology used herein is for the purpose of describing particular embodiments only, and is intended to be limiting as the scope of the invention will be limited only by the appended claims. It should also be understood that it is not intended.

  Where a range of values is provided, each intervening value between the upper and lower limits of the range, and any arbitrary value in the description range, unless otherwise explicitly indicated otherwise, up to 1 / 10th of the lower limit. It is understood that other descriptive values or intervening values are encompassed within the present invention. The upper and lower limits of these smaller ranges may be independently included in the smaller ranges according to any specifically excluded limits in the stated ranges and are also encompassed within the invention. Where the stated range includes one or both of the limit values, ranges excluding either or both of those included limit values are also included in the invention.

  A range is presented herein with a numerical value preceding the term “about”. The term “about” is used herein to provide literal support for the exact number that it precedes, as well as the number that is near or close to the number that the term precedes. In determining whether a number is close or close to a specifically listed number, an unrewarded number of close or approximate is the substance of the specifically listed number in the context in which it is presented. It may be a number that provides general equivalence.

  Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present invention, representative exemplary methods and materials are now described.

  All publications, patents, and patent applications mentioned in this specification are specifically and individually indicated as though each individual publication, patent, or patent application was incorporated by reference. Are incorporated herein by reference to the same extent. In addition, each cited publication, patent, or patent application is hereby incorporated by reference to disclose and describe the subject matter in relation to the subject matter for which the publication is cited. The citation of any publication is for its disclosure prior to the filing date and should not be construed as an admission that the invention described herein is not entitled to antedate such publication by the prior invention. Absent. Furthermore, the date of publication provided may be different from the actual publication date that needs to be independently verified.

  As used herein and in the appended claims, the singular forms “a”, “an”, and “the” are indicated to include a plurality of references unless the context clearly dictates otherwise. . It is further pointed out that the claims may have been drafted to exclude any optional element. Therefore, this statement should serve as an antecedent for the use of such exclusive terminology, such as “exclusive”, “only”, etc., or the use of “reactive” restrictions in connection with the enumeration of claim elements. Intended.

  As will be apparent to those skilled in the art upon reading this disclosure, each individual embodiment described and illustrated herein departs from the individual components and the scope and spirit of the present invention. Without having features that may be easily separated from or combined with features of any of several other embodiments. Any recited method can be performed in the order of events listed or in any other order that is logically possible.

The materials used to make the compositions of the present invention are first described in the section with particular attention to the CO ₂ source, divalent cations, and proton scavengers (and how to achieve proton scavenging). A description of metal-containing silicate materials and / or related materials that may be used in the present invention is also provided in the Materials section. Described next are methods by which materials (eg, CO ₂ , divalent cations, etc.) can be incorporated into the compositions of the present invention. Subsequently, the system of the present invention is described, followed by a description of the compositions of the present invention, products containing those compositions, and their use. The subject matter is organized for the convenience of the reader and in no way limits the scope of the invention. For example, if a particular metal-containing silicate material is to be disclosed or described in a section other than the section on metal-containing silicate materials (eg, the section on methods), this particular metal-containing silicate material is a metal-containing silicate. It should be understood that it is part of the material disclosure. Continuing the same example, it will be understood that the section on metal-containing silicate materials is not exclusive, and that additional metal-containing silicate materials may be used in the present invention without departing from the spirit and scope of the present invention. Should.

Materials As described in further detail below, the present invention utilizes a CO ₂ source, a proton scavenger source (and / or a method for achieving proton removal), and a divalent cation source to produce a precipitate. . Metallized silicate materials (eg, olivine, serpentine, and materials described further below) and / or related materials can provide a divalent cation source, either completely or partially. Thus, the metal-containing silicate material may be the only divalent cation source for the manufacture of the compositions described herein. Metal silicates and / or related materials may also be used in combination with a supplemental divalent cation source for the manufacture of the compositions described herein. Metal-containing silicate materials (eg, olivine, serpentine, and materials further described below) and / or related materials can also provide a proton scavenger source, either completely or partially. Thus, the metal-containing silicate material may be the only source of proton scavenger for the production of the compositions described herein. Metal silicates and / or related materials may also be used in combination with a supplemental proton scavenger source for the manufacture of the compositions described herein. In some embodiments, the metal silicate is not a proton scavenger source. In such embodiments, a proton scavenger described herein or a combination of those proton scavengers is a proton scavenger source for the manufacture of the compositions described herein. A source of carbon dioxide, a supplemental divalent cation source, and a proton removal source (and a method for achieving proton removal), the proton removal source of which may be provided as a supplemental source, is a metal-containing silicate material as a divalent cation source. Will be described first to relate to. Metal-containing silicate materials (eg, olivine, serpentine, etc.) are described next to produce a composition in which the metal-containing silicate material includes carbonate, silica, or a combination thereof. The method used continues.

Carbon dioxide The method of the present invention comprises contacting a volume of an aqueous solution of a divalent cation with a CO ₂ source and then subjecting the resulting solution to precipitation conditions. The method of the present invention further comprises contacting a volume of an aqueous solution of divalent cations with a CO ₂ source while subjecting the aqueous solution to precipitation conditions. Although sufficient carbon dioxide may be present in the divalent cation-containing solution to precipitate a significant amount of carbonate-containing precipitate (eg, from seawater); additional carbon dioxide is generally used. The CO ₂ source may be any convenient CO ₂ source. The CO ₂ source may be a gas, liquid, solid (eg, dry ice), supercritical fluid, or CO ₂ dissolved in a liquid. In some embodiments, the CO ₂ source is a gaseous CO ₂ source. The gas stream may be substantially pure CO ₂ or may include multiple components including CO ₂ and one or more additional gases and / or other materials such as ash and other particulates. . In some embodiments, the gaseous CO ₂ source is a waste gas stream, such as an exhaust gas from an industrial plant (ie, an by-product of an industrial plant active process). Power plants, chemical processing plants, machining plants, refineries, cement factories, steelworks, and other industrial plants that produce CO ₂ as a byproduct of fuel combustion or another processing step (such as calcination by a cement plant) The nature of industrial plants, including but not limited to, can vary.

Waste gas streams containing CO ₂ include both reducing streams (eg, synthesis gas, shift synthesis gas, natural gas, hydrogen, etc.) and oxidizing streams (eg, flue gas from combustion). Certain waste gas streams that may be advantageous for the present invention include oxygen-containing combustion industrial plant flue gas (eg, from coal or another carbon-based fuel with little or no flue gas pretreatment). ), Turbocharged boiler product gas, coal gasification product gas, shift coal gasification product gas, anaerobic digester product gas, wellhead natural gas stream, reformed natural gas or methane hydrate and the like. Combustion gases from any convenient source may be used in the methods and systems of the present invention. In some embodiments, combustion gases are used in post-combustion effluent chimneys of industrial plants such as power plants, cement factories, and coal processing plants.

  Thus, waste streams can be generated from a variety of different types of industrial plants. Waste streams suitable for the present invention include anthropogenic fuel products of fossil fuels (eg, coal, petroleum, natural gas) and organic fuel deposits of natural origin (eg, tar sands, heavy oil, oil shale, etc.) A waste stream produced by an industrial plant that burns is included. In some embodiments, suitable waste streams for the systems and methods of the present invention are from coal fired power plants, such as pulverized coal power plants, supercritical coal power plants, mass burning coal power plants, fluidized bed coal power plants, and the like. In some embodiments, the waste stream is gas or oil fired boiler and steam turbine power plant, gas or oil fired boiler simple cycle gas turbine power plant, or gas or oil fired boiler combined cycle gas turbine power plant. Procured from. In some embodiments, a waste stream produced by a power plant that burns synthesis gas (ie, gas produced by gasification of organic materials such as coal, biomass, etc.) is used. In some embodiments, a waste stream from an integrated gasification combined cycle (IGCC) plant is used. In some embodiments, a waste stream produced by a Heat Recovery Steam Generator (HRSG) plant is used in accordance with the systems and methods of the present invention.

  Waste streams generated from cement factories are also suitable for the systems and methods of the present invention. Cement factory waste streams include waste streams from both wet and dry process plants, which may use shaft kilns or rotary kilns and may include pre-calciners. Each of these industrial plants may burn a single fuel or may burn two or more fuels sequentially or simultaneously. Other industrial plants such as smelters and refineries are also useful sources of waste streams containing carbon dioxide.

The industrial waste gas stream may contain carbon dioxide as a non-air derived major component, or in particular in the case of coal-fired power plants, nitrogen oxides (NOx), sulfur oxides (SOx), and It may contain additional components such as one or more additional gases. Additional gases and other components may include CO, mercury and other heavy metals, and dust particles (eg, from calcination and combustion processes). Additional components in the gas stream also include halides such as hydrogen chloride and hydrogen fluoride; fly ash, dust, and arsenic, beryllium, boron, cadmium, chromium, chromium VI, cobalt, lead, manganese, mercury, molybdenum, Particulate materials such as metals including selenium, strontium, thallium, and vanadium; and organics such as hydrocarbons, dioxins, and PAH compounds may be included. Suitable gaseous waste streams that may be treated include, in some embodiments, from 200,000 ppm to 2000 ppm, such as from 180,000 ppm to 2000 ppm, or from 180,000 ppm to 5000 ppm, and from 180,000 ppm to It has CO ₂ present in an amount of 200 ppm to 1,000,000 ppm, such as 200,000 ppm to 1000 ppm, including 10,000 ppm. Waste stream, particularly various waste streams of the combustion gas, one or more additional ingredients, for example, water, NOx (mono nitrogen oxides: NO and _NO 2), SOx (mono sulfur oxides: SO, SO ₂ And SO ₃ ), VOC (volatile organic compounds), heavy metals such as mercury, and particulate matter (solid or liquid particles suspended in a gas). The flue gas temperature may also vary. In some embodiments, the temperature of the flue gas is from 0 ° C to 2000 ° C, such as from 60 ° C to 700 ° C, and including from 100 ° C to 400 ° C.

In some embodiments, one or more additional components contact a waste gas stream containing these additional components with an aqueous solution containing divalent cations (eg, alkaline earth metal ions such as Ca ²⁺ and Mg ²⁺ ). Precipitated or trapped in the precipitate formed. Calcium and magnesium sulfate and / or sulfite may precipitate in a precipitate (further comprising calcium carbonate and / or magnesium carbonate) formed from a waste gas stream comprising SOx (eg, SO ₂ ) or May be captured. Magnesium and calcium react to form MgSO ₄ , CaSO ₄ , and other magnesium- and calcium-containing compounds (eg, sulfites), respectively, without a desulfurization step such as flue gas desulfurization (“FGD”). It can effectively remove sulfur from the flue gas stream. In addition, CaCO ₃ , MgCO ₃ , and related compounds can be formed without additional release of CO ₂ . If the aqueous solution of divalent cations contains high levels of sulfur compounds (eg, sulfate), the aqueous solution may be calcium and magnesium after or in addition to the formation of CaSO ₄ , MgSO ₄ , and related compounds. May be rich in calcium and magnesium so that can be used to form carbonate compounds. In some embodiments, the desulfurization step may be performed to occur simultaneously with the precipitation of the carbonate-containing precipitate, or the desulfurization step may be performed to occur prior to precipitation. In some embodiments, multiple reaction products (eg, MgCO ₃ , CaCO ₃ , CaSO ₄ , mixtures described above, etc.) are collected at different stages, while in other embodiments, a single reaction product (E.g., precipitates containing carbonate, sulfate, etc.) are collected. In the process in these embodiments, other components, such as heavy metals (eg, mercury, mercury salts, mercury-containing compounds) may be trapped in the carbonate-containing precipitate or may be precipitated separately. Good.

  A portion of the gaseous waste stream from the industrial plant (ie, not the entire gaseous waste stream) may be used to produce a precipitate. In these embodiments, the portion of the gaseous waste stream used for sedimentation may be 75% or less, such as 60% or less, and including 50% or less of the gaseous waste stream. . In yet another embodiment, the entire gaseous waste stream produced by the industrial plant is used for substantially (eg, 80% or more) sedimentation. In these embodiments, 80% or more, 100% or less, such as 90% or more, including 95% or more, of the gaseous waste stream (eg, flue gas) produced by the source is sediment precipitation. May be used for

While industrial waste gas provides a relatively rich combustion gas source, the methods and systems of the present invention also include lower concentration sources (eg, containing much lower concentrations of pollutants than flue gas, for example). It can also be applied to a process for removing combustion gas components from atmospheric air). Thus, in some embodiments, the methods and systems include reducing the concentration of pollutants in atmospheric air by producing stable precipitates. In these cases, the concentration of contaminants such as CO ₂ in a part of the atmospheric air is 10% or more, 20% or more, 30% or more, 40% or more, 50% or more, 60% or more, 70%. %, 80% or more, 90% or more, 95% or more, 99% or more, 99.9% or more, or 99.99% or more. Such reduction of air pollutants can be accomplished in yields as described herein, or in higher or lower yields, and can be accomplished in one precipitation step or in a series of precipitation steps.

Divalent Cations As disclosed above, the metal-containing silicate materials (eg, olivine, serpentine), described in detail in the respective sections below, can be used to produce the compositions described herein. The metal-containing silicate material may also be used in combination with a supplemental divalent cation source as described in this section.

The method of the present invention involves contacting a volume of an aqueous solution of a divalent cation with a CO ₂ source and subjecting the resulting solution to precipitation conditions. In some embodiments, a volume of an aqueous solution of a divalent cation is contacted with a CO ₂ source while subjecting the aqueous solution to precipitation conditions. In addition to the divalent cations procured from the metal-containing silicate material, the divalent cations may be derived from any of a number of different divalent cation sources depending on availability at a particular location. Such sources include industrial waste, seawater, brine, hard water, minerals (eg, lime, periclase), and any other suitable source.

  In some locations, industrial waste streams from various industrial processes provide a convenient divalent cation source (as well as other materials useful in the process in some cases, such as metal hydroxides). To do. Such waste streams include mining waste; fossil fuel combustion ash (eg, fly ash, bottom ash, boiler slag, etc.); slag (eg, iron slag, phosphorus slag); cement kiln waste; / Petrochemical refinery waste (eg oil fields and methane bed brine); coal bed waste (eg gas production brine and coal bed brine); paper processing waste; water softening waste brine (eg ion exchange effluent); Agricultural waste; metal finish waste; high pH fiber waste; as well as, but not limited to, caustic sludge. Fossil fuel combustion ash, cement kiln dust, and further described in US patent application Ser. No. 12 / 486,692, filed Jun. 17, 2009, the disclosure of which is incorporated herein in its entirety. Slag, a collective metal oxide waste source, may be used in combination with a metal-containing silicate material, for example, to provide divalent cations to the present invention.

In some locations, a convenient divalent cation source for use in the systems and methods of the invention can vary depending on the particular location in which the invention is implemented, such as water (e.g., seawater or Aqueous solution containing divalent cations such as surface brine). Suitable aqueous solutions of divalent cations that may be used include solutions containing one or more divalent cations, for example alkaline earth metal cations such as Ca ²⁺ and Mg ²⁺ . In some embodiments, the aqueous source of divalent cations comprises an alkaline earth metal cation. In some embodiments, the alkaline earth metal cation includes calcium, magnesium, or a mixture thereof. In some embodiments, the aqueous solution of divalent cations is in an amount ranging from 50 to 50,000 ppm, 50 to 40,000 ppm, 50 to 20,000 ppm, 100 to 10,000 ppm, 200 to 5000 ppm, or 400 to 1000 ppm. Contains calcium. In some embodiments, the aqueous solution of divalent cations is in an amount ranging from 50 to 40,000 ppm, 50 to 20,000 ppm, 100 to 10,000 ppm, 200 to 10,000 ppm, 500 to 5000 ppm, or 500 to 2500 ppm. Contains magnesium. In some embodiments where both Ca ²⁺ and Mg ²⁺ are present, the ratio of Ca ²⁺ to Mg ^{2+ in} the aqueous solution of divalent cations (ie, Ca ²⁺ : Mg ²⁺ ) is from 1: 1 to 1: 2. 5; 1: 2.5 to 1: 5; 1: 5 to 1:10; 1:10 to 1:25; 1:25 to 1:50; 1:50 to 1: 100; 1: 100 to 1. 1: 150; 1: 150-1: 200; 1: 200-1: 250; 1: 250-1: 500; 1: 500-1: 1000, or a range thereof. For example, in some embodiments, the ratio of Ca ²⁺ to Mg ^{2+ in} an aqueous solution of divalent cations is 1: 1 to 1:10; 1: 5 to 1:25; 1:10 to 1:50; : 25 to 1: 100; 1:50 to 1: 500; or 1: 100 to 1: 1000. In some embodiments, the ratio of Mg ²⁺ to Ca ^{2+ in} the aqueous solution of divalent cations (ie, Mg ²⁺ : Ca ²⁺ ) is 1: 1 to 1: 2.5; 1: 2.5 to 1: 5; 1: 5 to 1:10; 1:10 to 1:25; 1:25 to 1:50; 1:50 to 1: 100; 1: 100 to 1: 150; 1: 150 to 1: 200; 1: 200-1: 250; 1: 250-1: 500; 1: 500-1: 1000, or a range thereof. For example, in some embodiments, the ratio of Mg ²⁺ to Ca ^{2+ in} an aqueous solution of divalent cations is 1: 1 to 1:10; 1: 5 to 1:25; 1:10 to 1:50; : 25 to 1: 100; 1:50 to 1: 500; or 1: 100 to 1: 1000.

  Aqueous solutions of divalent cations include fresh water, hemi-saline water, sea water, or brine (eg, naturally occurring brine or artificial brine such as geothermal plant waste water, desalination plant waste water), as well as others having a salinity greater than that of fresh water May contain divalent cations derived from a salt solution of any of which may be of natural origin or artificial. Half salt water is more salty than fresh water, but it contains less salt than sea water. Half-saline has a salinity in the range of about 0.5 to about 35 ppt (parts per thousand). Seawater is water from the sea, ocean, or any other salt body of water having a salinity in the range of about 35 to about 50 ppt. Brine is water saturated or nearly saturated with salt. Brine has a salinity that is about 50 ppt or more. In some embodiments, the water source from which the divalent cation is derived is a mineral rich (eg, calcium rich and / or magnesium rich) fresh water source. In some embodiments, the water source from which the divalent cation is derived is a naturally occurring salt water source selected from the sea, ocean, lake, wetland, estuary, lagoon, surface brine, ridge brine, alkaline lake, and the like. In some embodiments, the water source from which the divalent cation is derived is an artificial brine selected from geothermal plant wastewater or desalted wastewater.

Fresh water is often a convenient source of divalent cations (eg, alkaline earth metal cations such as Ca ²⁺ and Mg ²⁺ ). Any of a number of suitable freshwater sources may be used, including freshwater sources ranging from relatively mineral-free sources to sources that are relatively rich in minerals. Mineral-rich freshwater sources, including any of a number of hard water sources, lakes, or inland seas, may be of natural origin. Some mineral-rich freshwater sources such as alkaline lakes or inland seas (eg Lake Van, Turkey) also provide a source of pH modifiers. Mineral-rich freshwater sources may also be artificial. For example, mineral-poor (soft) water produces alkaline earth metal cations (eg, Ca ²⁺ , Mg ^2+, etc.) to produce mineral-rich water that is suitable for the methods and systems described herein. May be contacted with a divalent cation source such as Divalent cations or their precursors (eg, salts, minerals) can be prepared using fresh water (or any of those described herein) using any convenient protocol (eg, addition of solids, suspensions, or solutions). Other types of water). In some embodiments, a divalent cation selected from Ca ²⁺ and Mg ²⁺ is added to fresh water. In some embodiments, a monovalent cation selected from Na ⁺ and K ⁺ is added to fresh water. In some embodiments, fresh water containing Ca ²⁺ is combined with combustion ash (eg, fly ash, bottom ash, boiler slag), or their product or treatment form, resulting in a solution containing calcium and magnesium cations.

  In some embodiments, an aqueous solution of divalent cations may be obtained from an industrial plant that is also providing a combustion gas stream. For example, in a water-cooled industrial plant, such as a seawater cooling industrial plant, the water used by the industrial plant to cool may then be used as water to produce a precipitate. If necessary, the water may be cooled before entering the precipitation system. Such an approach may be used, for example, in a once-through cooling system. For example, a city or agricultural water supply may be used as a once-through cooling system for an industrial plant. Water from an industrial plant may then be used to produce a precipitate, where the output water has a reduced hardness and higher purity. If necessary, such systems may be modified to include safety measures (eg, to detect toxic contamination such as the addition of toxicants), but may be governmental (eg, Homeland Security) or other agencies. ). Additional poisoning or attack prevention measures may be used in such embodiments.

Proton scavengers and methods Metal-containing silicate materials may be used in combination with other proton scavenger sources (and how to achieve proton removal) as described in this section.

The method of the present invention comprises contacting a volume of an aqueous solution of a divalent cation with a CO ₂ source (to dissolve CO ₂ ) and subjecting the resulting solution to precipitation conditions. In some embodiments, a volume of an aqueous solution of a divalent cation is contacted with a source of CO ₂ (to dissolve the CO ₂₎ while subjecting the aqueous solution to precipitation conditions. Dissolution of CO _{2 in} an aqueous solution of a divalent cation produces a species that is in equilibrium with both carbonic acid, bicarbonate, and carbonate. Protons are removed from various species in divalent cation-containing solutions (eg, carbonate, bicarbonate, hydronium, etc.) to shift the equilibrium towards carbonate to produce carbonate-containing precipitates Is done. As the proton is removed, more CO ₂ dissolves into the solution. In some embodiments, the proton scavenger and / or method is used while contacting the divalent cation-containing aqueous solution with CO ₂ to enhance CO ₂ absorption in one aspect of the precipitation reaction, where the pH is constant. It may remain, increase or decrease further, followed by rapid removal of protons (eg, by addition of base) to result in fast precipitation of the carbonate-containing precipitate. Protons are any, including but not limited to, use of naturally occurring proton scavengers, use of microorganisms and fungi, use of synthetic chemical proton scavengers, recovery of man-made waste streams, and use of electrochemical means May be removed from various chemical species (eg, carbonic acid, bicarbonate, hydronium, etc.) by this convenient approach.

  Naturally-occurring proton scavengers include any proton scavenger that can be found in a wider environment that can create or have a basic local environment. Some embodiments provide a naturally occurring proton scavenger that includes minerals that when added to a solution create a basic environment. Such minerals include, but are not limited to, lime (CaO); periclase (MgO); iron hydroxide minerals (eg goethite and limonite); and volcanic ash. Provided herein are methods for digestion of such minerals and rocks containing such minerals. Some embodiments provide for using the natural alkaline form of water as a naturally occurring proton scavenger. Examples of natural alkaline bodies of water include, but are not limited to, surface water sources (eg, alkaline lakes such as California Lake Mono Lake) and groundwater sources (eg, basic aquifers). Other embodiments provide for the use of deposits from dry alkaline bodies of water, such as the crust along the Lake Natron of Great Lift Valley, Africa. In some embodiments, organisms that secrete basic molecules or solutions in their normal metabolism are used as proton scavengers. Examples of such organisms include fungi that produce alkaline proteases (eg, the deep-sea fungus Aspergillus ustus at an optimal pH of 9) as well as bacteria that produce alkaline molecules (eg, British Columbia's Atlin wetlands that raise pH from photosynthesis by-products). From Cybacteria such as Lyngbya species). In some embodiments, the organism is used to produce a proton scavenger, where the organism (eg, Bacillus pasturii that hydrolyzes urea to ammonia) metabolizes contaminants (eg, urea). To produce a solution containing a proton remover or proton remover (eg, ammonia, ammonium hydroxide). In some embodiments, the organism is cultured separately from the precipitation reaction mixture, wherein a proton scavenger or a solution containing the proton scavenger is used for addition to the precipitation reaction mixture. In some embodiments, naturally occurring or manufactured enzymes are used in combination with a proton scavenger to cause precipitation of the precipitate. Carbonic anhydrase, an enzyme produced by plants and animals, accelerates the conversion of carbonic acid to bicarbonate in aqueous solution. Thus, carbonic anhydrase may be used to accelerate precipitation of the precipitate.

Chemicals to achieve proton removal generally mean synthetic chemicals that are produced in large quantities and are commercially available. For example, chemicals for removing protons include, but are not limited to hydroxides, organic bases, superbases, oxides, ammonia, and carbonates. Hydroxides include, for example, sodium hydroxide (NaOH), potassium hydroxide (KOH), calcium hydroxide (Ca (OH) ₂ ), or magnesium hydroxide (Mg (OH) ₂ ) in solution. Chemical species that provide hydroxide anions are included. Organic bases include primary amines such as methylamine, secondary amines such as diisopropylamine, tertiary amines such as diisopropylethylamine, aromatic amines such as aniline, heterocyclics such as pyridine, imidazole, and benzimidazole. Aromatic compounds, as well as carbon-containing molecules that are generally nitrogenous bases, including various forms thereof. In some embodiments, an organic base selected from pyridine, methylamine, imidazole, benzimidazole, histidine, and phosphazene is used for various species (e.g., carbonic acid, bicarbonate, hydronium) for precipitation of the precipitate. Etc.) used to remove protons. In some embodiments, ammonia is used to raise the pH to a level sufficient to precipitate the precipitate from divalent cation solutions and industrial waste streams. Superbases suitable for use as proton scavengers include sodium ethoxide, sodium amide (NaNH ₂ ), sodium hydride (NaH), butyllithium, lithium diisopropylamide, lithium diethylamide, and lithium bis (trimethylsilyl) amide. included. For example, oxides including calcium oxide (CaO), magnesium oxide (MgO), strontium oxide (SrO), beryllium oxide (BeO), and barium oxide (BaO) are also suitable proton scavengers that may be used. is there. Carbonates for use in the present invention include, but are not limited to sodium carbonate.

In addition to including cations of interest and other suitable metal forms, waste streams from various industrial processes can provide proton scavengers. Such waste streams include: mining waste; fossil fuel combustion ash (eg, fly ash, bottom ash, boiler slag, etc.); slag (eg, iron slag, phosphorus slag); cement kiln waste; / Petrochemical refinery waste (eg oil fields and methane bed brine); coal bed waste (eg gas production brine and coal bed brine); paper processing waste; water softening waste brine (eg ion exchange effluent); Agricultural waste; metal finish waste; high pH fiber waste; as well as, but not limited to, caustic sludge. Mining waste includes any waste from the extraction of metals or other valuable or useful minerals from the earth. In some embodiments, waste from mining is used to correct the pH, where the waste is red mud from Bayer aluminum extraction process; waste from magnesium extraction from seawater (eg, Moss Landing, Mg (OH) ₂ ) such as that found in California; and waste from mining processes including leaching. For example, red mud modifies pH as described in US Provisional Patent Application No. 61 / 161,369, filed Mar. 18, 2009, which is hereby incorporated by reference in its entirety. May be used for Fossil fuel combustion ash, cement kiln dust, and further described in US patent application Ser. No. 12 / 486,692, filed Jun. 17, 2009, the disclosure of which is incorporated herein in its entirety. Slag, a collective metal oxide waste source, may be used alone or in combination with other proton scavengers to provide proton scavengers to the present invention. Agricultural waste, either from animal waste or excessive fertilizer use, can contain potassium hydroxide (KOH) or ammonia (NH ₃ ) or both. Thus, agricultural waste may be used as a proton scavenger in some embodiments of the present invention. This agricultural waste is often collected in a pond, but it can also penetrate into the aquifer, where it can be accessed and used.

Electrochemical methods involve either removing protons from solutes (eg, deprotonation of carbonic acid or bicarbonate) or removing protons from solvents (eg, deprotonation of hydronium or water) in solution. Is another method for removing protons from various chemical species. For example, if proton production from CO ₂ dissolved or exceeds it matches the electrochemical proton removal from solute molecules, there is a possibility that the deprotonation of the solvent occurs. In some embodiments, for example, when CO ₂ is dissolved in the precipitation reaction mixture or a precursor solution to the precipitation reaction mixture (ie, a solution that may or may not contain divalent cations). A low voltage electrochemical method is used to remove protons. In some embodiments, CO ₂ dissolved in an aqueous solution that does not contain divalent cations removes protons from any species or combination thereof resulting from dissolution of carbonic acid, bicarbonate, hydronium, or CO _2. In order to be processed by low voltage electrochemical methods. Low voltage electrochemical methods include 0.9V or less, 0.8V or less, 0.7V, such as 1V or less, such as 1.5, 1.4, 1.3, 1.2, 1.1V or less. Below, 2, 1.9, 1.8, 1.7, or less, such as 0.6 V or less, 0.5 V or less, 0.4 V or less, 0.3 V or less, 0.2 V or less, or 0.1 V or less Operates with an average voltage of 1.6V or less. Low voltage electrochemical methods that do not generate chlorine gas are advantageous for use in the systems and methods of the present invention. Low voltage electrochemical methods for removing protons that do not generate oxygen gas are also advantageous for use in the systems and methods of the present invention. In some embodiments, the low voltage electrochemical method generates hydrogen gas at the cathode and carries it to the anode where it is converted to protons. Electrochemical methods that do not generate hydrogen gas may also be advantageous. In some cases, electrochemical methods for removing protons do not generate any gaseous by-products. Electrochemical methods for achieving proton removal are described in US patent application Ser. No. 12 / 344,019, filed Dec. 24, 2008, each of which is hereby incorporated by reference in its entirety. Description: US Patent Application No. 12 / 375,632, filed December 23, 2008; International Patent Application PCT / US Application No. 08/088822, filed December 23, 2008; International Patent Application No. PCT / US Patent Application No. 09/32301, filed Jan. 28, 2009; and International Patent Application No. PCT / US Patent Application No. 09/48511, filed June 24, 2009. Are further described.

Alternatively, electrochemical methods may be used to generate caustic molecules (eg, hydroxides), for example, by the chlor-alkali method, or improvements thereof. Electrodes (ie, cathodes and anodes) may be present in devices containing divalent cation-containing aqueous solutions or gaseous waste stream full (eg, CO ₂ full) solutions, and there are selective barriers such as membranes The electrodes may be separated. Electrochemical systems and methods for removing protons can produce by-products (eg, hydrogen) that may be harvested and used for other purposes. Additional electrochemical approaches that may be used in the systems and methods of the present invention include US Provisional Patent Application No. 61 / 081,299, the disclosures of which are hereby incorporated by reference. Although what is described in 61 / 091,729 specification is included, it is not limited to them.

Metal-containing silicate materials As disclosed above, as disclosed in further detail below, the present invention provides a source of CO _{2, a} source of proton scavenger (and / or a method for achieving proton removal), and a divalent cation. Use the source. Metal-containing silicate materials (eg, metal silicates such as serpentine and shellfish shells; rocks containing metal silicates) are sources of divalent cations (eg, Ca ²⁺ , Mg ²⁺ ), proton removing agents (eg, CaO and MgO) Metal oxides; metal hydroxides such as Ca (OH) ₂ and Mg (OH) ₂ ) sources, or both. Furthermore, the metal-containing silicate material can provide a silica content to the composition of the present invention. In some embodiments, the metal-containing silicate material provides the only divalent cation source for the production of the compositions described herein. In some embodiments, the metal-containing silicate material is used in combination with a supplemental divalent cation source. Similarly, in some embodiments, the metal-containing silicate material provides the only source of proton scavenger for the manufacture of the compositions described herein. In some embodiments, the metal-containing silicate material is used in combination with a supplemental proton remover source. In some embodiments, the metal-containing silicate material provides the only divalent cation source and proton remover source for the production of the compositions described herein. For example, in some embodiments, serpentine minerals such as chrysotile may be the hydroxide source. In such embodiments, the metal-containing silicate material (eg, serpentine) may be digested or dissolved in water. In order to achieve optimal digestion or dissolution, the metal-containing silicate material may be comminuted and / or sonicated with a solution. The metal-containing silicate material may also simply be in solution for a certain amount of time (eg, day, month, year). In some embodiments, the metal-containing silicate material is used in combination with a supplemental divalent cation source and a supplemental proton remover source. In some embodiments, the silica present in the composition of the present invention is a metallized silicate material, or a metallized silicate material and a supplemental silica source (eg, fly ash, cement kiln dust, and / or other artifacts). Source). Methods in which the metal-containing silicate material is used alone or in combination with other divalent cation sources and proton remover sources are further described below.

Naturally occurring solid aggregates, including rocks, minerals and / or quasi-minerals, in particular magnesium and / or to provide divalent cations such as Mg ²⁺ and / or Ca ²⁺ upon processing (eg size reduction, digestion) Rocks containing calcium (eg, peridotite, basalt, gabbro, diorite, etc.) are suitable for the present invention and are often convenient. Rocks can also provide silica content to the compositions of the present invention as well. Minerals having a characteristic composition of highly ordered atomic structure and unique physical properties are generally more suitable for the present invention. Similar to rocks, minerals containing magnesium and / or calcium can be treated to provide divalent cations such as Mg ²⁺ and / or Ca ²⁺ to the present invention. Minerals containing magnesium and / or calcium can also be treated with silicon such as silicates (eg, calcium silicates, magnesium silicates, aluminosilicates, iron-owned silicates, and mixtures thereof) to provide silica to the compositions of the present invention. Metal silicates), which together contain at least one metal, their compositions exhibit pozzolanic properties. In some embodiments, minerals are treated only for their silica-providing content; that is, in some embodiments, calcium (which results in divalent cations such as Ca ²⁺ and / or Mg ²⁺ ) and A low or negligible amount of metal-containing silicate material with magnesium is treated for silica-providing content. It should be understood that pure or impure minerals are suitable for the present invention since rocks may be used in the present invention.

A number of different metallized silicate materials are suitable for use in the present invention, including naturally occurring metallized silicate materials such as those present in rocks, minerals, and mineral rich clays. Metal silicates that may be used in the present invention include, but are not limited to, orthosilicates, inosilicates, phyllosilicates, and tectosilicates. Orthosilicates include, for example, olivine group minerals ((Mg, Fe) ₂ SiO ₄ ), where olivine minerals rich in magnesium (ie, iron olivine (Fe ₂ SiO ₄ )) and On the contrary, it is generally preferred to be dolomite (Mg ₂ SiO ₄ ). Inosilicates (“chain silicates”) include, for example, pyroxene group minerals (XY (Si, Al) ₂ O ₆ ), where X is calcium, sodium, iron (eg, Fe ²⁺ ), or magnesium. Represents an ion, and Y represents a single chain ion such as chromium, aluminum, iron (eg Fe ³⁺ , even Fe ²⁺ ), magnesium, manganese, scandium, titanium, and vanadium). Pyroxene-group minerals that include silicates and are rich in magnesium (eg, closer to the institute (Mg ₂ Si ₂ O ₆ ) as opposed to ferrosilite (Fe ₂ Si ₂ O ₆ )) are generally preferred. Single chain inosilicates also include, for example, wollastonite (CaSiO ₃ ), commonly in contact-metamorphosed limestone, and sodium ash needle (NaCa ₂ ), which are also suitable for use in the present invention. Pyroxenoid minerals such as (Si ₃ O ₈ ) (OH)) are included. The duplex Ino silicates, for example, include amphibole group minerals such as anthophyllite _{((Mg, Fe) 7 Si} 8 O 22 (OH) 2). Examples of phyllosilicates (ie, layered silicates) include serpentine group minerals (eg, antigolite, chrysotile, and / or serpentine ((Mg, Fe) ₃ Si ₂ O ₅ (OH) ₄ ) Form), phyllosilicate clay minerals (for example, montmorillonite (Na, Ca) _0.33 (Al, Mg) ₂ (Si ₄ O ₁₀ ) (OH) ₂ .nH ₂ O and talc Mg ₃ Si ₄ O ₁₀ (OH) ₂ ), as well as mica group minerals such as biotite K (Mg, Fe) ₃ (AlSi ₃ O ₁₀ ) (OH) ₂ ). Tectosilicates (ie, skeletal silicates) that are aluminosilicates (excluding quartz group minerals) include, for example, sodium feldspar ((Na, Ca) (Si, Al) ₄ O ₈ (Na: Ca2: 3) and ash Includes plagioclase such as feldspar (CaAl ₂ Si ₂ O ₈ ).

Mafic and ultramafic minerals (ie, magnesium and iron rich silicate-containing minerals, sometimes referred to as magnesium silicates), each having less than 52% SiO ₂ and less than 45% SiO ₂ are Some subpopulations of the described metal silicates. Accordingly, mafic and ultramafic (ie, generally> 18% MgO, high Fe content, low potassium content) minerals, and their products or treatment forms are also suitable for use in the present invention. It is. Mafic and ultramafic rocks (generally> 90% mafic minerals), including mafic and ultramafic minerals, are equally well suited for the present invention. Such rocks include, but are not limited to, pyroxene, troctolite, dunite, peridotite, basalt, gabbro, diorite, and soapstone. Common rock-forming mafic minerals include olivine, pyroxene, amphibole and biotite. A significant amount of olivine and serpentine-bearing rocks are present all over the world, especially in ultramafic complexes and in large serpentine bodies. Serpentine is an abundant natural source mineral with small amounts of elements such as chromium, manganese, cobalt and nickel. Thus, serpentine may mean any of 20+ variants belonging to the serpentine family. Olivines are naturally occurring magnesium-iron silicates ((Mg, Fe) ₂ SiO ₄ ) ranging from mafic olivine (Fo) (MgSiO ₄ ) to iron olivine (Fa) (Fe ₂ SiO ₄ ). ). Thus, the olivine may be, for example, Fo ₇₀ Fa ₃₀ (where the subscript indicates the molar ratio of bituminous olivine (Fo) to iron olivine (Fa)). In general, olivines richer in bitter olivine are preferred. Due to the structure, the olivine group also includes Monticerite (CaMgSiO ₄ ) and Kirschsteinite (CaFeSiO ₄ ). Wollastonite is a naturally occurring calcium silicate that is also convenient for the present invention.

Systems and Methods A method for producing a carbonate-containing composition comprising silica from a carbon dioxide source, a divalent cation-containing solution, and a proton remover source is provided. Also provided are methods of making carbonate-containing compositions that contain little or no silica. In such methods, silicon-based materials (eg, silica, unreacted or undigested silicates, etc.) may be separated at an early point in the method and processed separately from the carbonate-containing composition. The silicon-based material and the carbonate-containing material may be blended at a later stage to produce a specific ratio of component compositions. The carbonate composition comprising silica may be further processed and blended with, for example, Portland cement.

FIG. 1 illustrates a general sequence of steps in which a carbonate-containing precipitate (690, 255) can be produced from a metal-containing silicate material (240), which steps are discussed in further detail in the following paragraphs. The The particle size of the initial metallized silicate material may be first reduced in size (ie, finely crushed) as in step 610 using a combination of crushing, crushing, and sieving, and the process is consistent It may be repeated to produce a particle size metallized silicate material. The comminuted metal-containing silicate material may then be suspended in an aqueous solution as in step 620, which solution generally contains a portion of the divalent cation that will result in the precipitate of the present invention. . As described below, the concentration of the finely divided metal-containing silicate material in the suspension can be anywhere from 1-1280 g / L. After suspension of the finely divided metal-containing silicate material, the metal-containing silicate material is digested as in step 630. The digestion of the metal-containing silicate material, including but not limited to dissolution of the metal-containing silicate material, may be performed to any desired degree. Accordingly, digestion conditions (eg, temperature, agitation method (if any), time, etc.) may vary as described below. The digestion may be performed, for example, under ambient conditions (ie, room temperature and pressure). After digestion of the metal-containing silicate material, the resulting digestion mixture may optionally be filtered in a filtration step (640) to remove silica and / or undigested silicon-based material. Since the concentration of silica and other silicon-based products of digestion can increase at a faster rate than the concentration of divalent cations, silica and other silicon-based products can be used to optimize divalent cation extraction. It may be advantageous to filter the product. The precipitate is then precipitated from an aqueous solution thereof containing a digested metal-containing silicate material or divalent cation and silica and / or other silicon-based material, depending on the degree of filtration (650 ). As described in detail further herein, the precipitation of the precipitate is the introduction (or proton removal) of CO ₂ and, if the solution is not already basic, one or more proton removal agents. The method of achieving the above. Once formed, the precipitate is then separated from the precipitation reaction mixture in a separation step (660), including a liquid-solid separator as described in more detail below. After separation, the precipitate may optionally be rinsed in a rinse step (670) to remove, for example, soluble chlorides, sulfates, nitrates, and the like. The precipitate may be dried whether freshly separated in the separation step 660 or freshly rinsed as in the rinse step 670. The drying step 680 may include reconstitution of the precipitate so that a slurry of the precipitate is fed to a spray dryer and dried to a consistent size to produce a dry precipitate 690, which precipitate is pozzolanic. Material 255 may be used.

In general, metal-containing silicate materials (eg, rocks containing metal silicate minerals) have a wide range of initial particle sizes. Thus, it is desirable to comminute the starting metal-containing silicate material, which may be accomplished with any suitable device or combination of devices. The size reduction of the starting metal-containing silicate material may begin with crushing. The crushed metal-containing silicate material may then be reduced to a smaller particle size by grinding. Milling may include the use of a mill such as a jet mill or a ball mill. The ground metallized silicate material may then be screened (eg, by sieving, cyclone, etc.) to select a metallized silicate material within a specific size distribution range. The sorted metal-containing silicate material that falls outside the specified size distribution range may be returned to the grinder and further crushed. Selected metal-containing silicate materials that fall within a specific size distribution range can be used directly (ie, proceeded to digestion of the silicate material) or, optionally, are subject to further processing in an iterative process. May be. In some embodiments, the metal-containing silicate material has a particle size of less than 10,000 microns, less than 1000 microns, less than 750 microns, less than 500 microns, less than 400 microns, less than 300 microns, less than 200 microns, less than 100 microns, 75 It may be reduced to an average diameter of less than micron, less than 50 microns, less than 25 microns, or less than 10 microns. Further processing of the screen-selective metal-containing silicate material may include magnetic separation to separate magnetic material such as magnetite (Fe ₃ O ₄ ) followed by optional heat treatment.

  Digestion of metal silicates (eg, mafic and ultramafic minerals such as olivine and serpentine; wollastonite) and / or related materials is a divalent cation, silicon for use in the present invention. The base material, and in some embodiments, may be achieved using any convenient protocol that provides a proton scavenger. Digestion of metal-containing silicate materials can include water (eg, deionized water, distilled water) or divalent cation-containing aqueous solutions such as fresh water, half-salt water, sea water, or brine (natural or artificial brine). It may occur in a solvent. Aqueous solutions, whether of natural origin or from an anthropoid source, generally contain at least a portion of divalent cations for use in the present invention. Further, the aqueous solution may be acidic or basic, and exposure to it may accelerate the digestion of the metal-containing silicate material. Digestion may also be accelerated by increasing the surface area, such as by particle size reduction (described above), as well as, for example, by using ultrasonic techniques (eg, inertial cavitation). The metal-containing silicate material may be contacted with the divalent cation-containing solution in a variety of processes, including batch, semi-batch, and continuous processes to produce a slurry containing silicon-containing material. For example, the mafic mineral may be mixed with a divalent cation-containing solution in a tank, and the solution may be agitated or otherwise agitated. After a period of time, the slurry is withdrawn from the tank and the tank is recharged with fresh metal-containing silicate material and divalent cation-containing solution. In some embodiments, the reaction may occur in one or more continuous stirred tank reactors in a continuous flow process. In some embodiments, the metal-containing silicate material is placed in a packed column and infiltrated into the metal-containing silicate material where the divalent cation-containing solution is placed. In some embodiments, a slurry comprising a divalent cation and a silicon-containing material is continuously withdrawn from the top of a vertical column that is filled with a metal-containing silicate material.

  In some embodiments, the metal-containing silicate material provides a source of proton scavenger completely or partially. Thus, the metal-containing silicate material may be the only source of proton scavenger for the production of the compositions described herein. The metal-containing silicate material may also be used in combination with a supplemental proton scavenger source for the production of the compositions described herein. As noted above, digestion of the metal-containing silicate material may occur in a solvent such as water or an aqueous solution such as fresh water, half-salt water, sea water or brine. Aqueous solutions, whether natural or artificial, generally contain at least some divalent cations for use in the present invention and may be basic. Such digestion of the metal-containing silicate material in an aqueous solution provides additional divalent cations and / or proton scavengers to the aqueous solution.

  In some embodiments, the metal-containing silicate material provides a silica source to the pozzolanic material of the present invention, in whole or in part. Thus, the metal-containing silicate material may be the sole silica source for the production of the compositions described herein. The metal-containing silicate material may also be used in combination with a supplemental silica source for the manufacture of the compositions described herein. Digestion of the metal-containing silicate material may occur in a solvent such as water or an aqueous solution, after which the undigested metal-containing silicate material and / or insoluble silicon-based material (eg, excess silica) is removed. May be. The undigested metal-containing silicate material and / or insoluble silicon-based material (eg, excess silica) may later be discarded or, in some embodiments, combined with a carbonate-containing precipitate. Alternatively, the material can already be a pozzolanic material (provided sufficient silica was dissolved during digestion). Depending on the amount of amorphous silica in the carbonate-containing precipitate, other, including but not limited to, volcanic ash, fly ash, silica fume, highly reactive metakaolin, and ground granulated blast furnace slag A siliceous product may be incorporated.

  The concentration of the metal-containing silicate material for digestion is 1 to 10 g / L, 10 to 20 g / L, 20 to 30 g / L, 30 in water or an aqueous solution (for example, fresh water, half salt water, sea water, or brine). It may be -40 g / L, 40-80 g / L, 80-160 g / L, 160-320 g / L, 320-640 g / L, 640-1280 g / L, or a range thereof. For example, in some embodiments, the concentration of the metal-containing silicate material for digestion is 1-40 g / L, 10-80 g / L, 20-160 g / L, 40-320 g / L, 80-640 g / L. L or 160-1280 g / L may be sufficient. The temperature may be adjusted to optimize metal-containing silicate material digestion. In some embodiments, the metal-containing silicate material is digested at room temperature (about 70 ° F.) to 220 ° F. In some embodiments, the metal-containing silicate material is 70-100 ° F., 100-220 ° F., 120-220 ° F., 140-220 ° F., 160-220 ° F., 100-200 ° F., 100 It is digested within one or more temperature ranges selected from ˜180 ° F., 100-160 ° F., and 100-140 ° F. Where auxiliary heating is required to increase the temperature, for example, waste heat from flue gas may be used. Other external heat sources (eg hot water) may be used as well. The digestion time may also be adjusted to optimize the digestion of the metal-containing silicate material. In some embodiments, the metal-containing silicate material is digested for 1 hour to 200 hours. In some embodiments, the metal-containing silicate material is 1 hour to 2 hours, 2 hours to 4 hours, 4 hours to 6 hours, 6 hours to 8 hours, 8 hours to 10 hours, 10 hours to 20 hours, 20 hours, It is digested for a period of time to 40 hours, 40 hours to 60 hours, 60 hours to 80 hours, 80 hours to 100 hours, 100 hours to 150 hours, 150 hours to 200 hours, or a range thereof. For example, in some embodiments, the metal-containing silicate material is ultra-digested for 1-10 hours, 2-20 hours, 4-80 hours, 10-150 hours, or 150 hours. Metal-containing silicate material digestion may be further optimized by including chelates that accelerate the digestion reaction rate. Examples of chelates that may be used in the present invention include acids such as acetic acid, ascorbic acid, citric acid, dicarboxymethyl glutamic acid, malic acid, oxalic acid, phosphoric acid, and succinic acid; amino acids; ferrichrome, desferri Ironophiles such as oxamine B, desferrioxamine E, fusarinin C, ornivacactin, enterobactin, basilibactin, vibriobactin, azotobactin, piovertine, and yercinia bactin; EDTA; EGTA; EDDS; and NTA However, it is not limited to them.

In some embodiments, the proton scavenger such as a metal hydroxide (eg, Mg (OH) ₂ , Ca (OH) ₂ ) is an aqueous alkaline hydroxide (eg, NaOH) or any other suitable It may be made available for use by digestion of one or more metal-containing silicate materials (eg, olivine and serpentine) with caustic. Any suitable concentration of aqueous alkaline hydroxide or other caustic may be used to decompose the metal-containing silicate material, including high concentrations and very dilute solutions. The concentration (by weight) of alkali hydroxide (e.g. NaOH) in the solution may be, for example, 30% -80% and 70% -20% water. In some embodiments, digestion of metal-containing silicate materials and / or other rocks and minerals is achieved over a pH range that includes pH 6.9 to pH 7.5, pH 7.5 to pH 8 0.0, pH 8.0 to pH 8.5, pH 8.5 to pH 9.0, pH 9.0 to pH 9.5, pH 9.5 to pH 10.0, pH 10.0 to pH 10.5, pH 10.5 to pH 11.0 PH 11.0 to pH 11.5, pH 11.5 to pH 12.0, pH 12.0 to pH 12.5, pH 12.5 to pH 13.0, pH 13.0 to pH 13.5, and pH 13.5 to pH 14.0. included. For example, in some embodiments, the digestion of the metal-containing silicate material is pH 6.9-pH 8.0, pH 6.9-pH 9.0, pH 8.0-pH 10.0, pH 8.0-pH 11.0, It is achieved at pH 8.0 to pH 12.0, or pH 9.0 to pH 14.0. For example, olivine may be digested in an aqueous solution with a pH ranging from 7.0 to 9.0, which is caused by dissolution of the proton scavenger. Since the solubility of silica increases at higher pH, the pozzolanic materials of the present invention resulting from such metal silicate digestion may have proportionately more silicon-based materials (eg, silica). In addition, the resulting pozzolanic material may be more reactive due to the increased amount of amorphous silica. Advantageously, the metal-containing silicate material digested with aqueous alkali metal hydroxide may be used directly to produce a precipitate. In addition, the valuable base from the precipitation reaction mixture may be recovered and reused to digest additional metal-containing silicate materials and the like.

Metal-containing silicate materials (eg, magnesium silicates such as olivine) and / or other rocks and minerals containing metal species of interest are also eg based on divalent cations (eg Mg ²⁺ , Ca ²⁺ ) and silicon-based Aqueous aqueous solutions (eg, HCl (aqueous), each of which is optionally from an electrochemical process) to produce a slurry comprising material (eg, silica, unreacted or undigested silicate, etc.) , H ₂ SO ₄ (aqueous)). Digestion of metal-containing silicate materials (eg, olivine) and / or other rocks and minerals of interest may be achieved by contact with an acidic solution to produce a slurry containing SiO ₂ . An aqueous solution of a divalent cation may be sufficiently acidic to be acceptable, and in such embodiments, the aqueous solution may be used without further pH adjustment; in some embodiments, The aqueous solution is either basic or not sufficiently acidic to be acceptable. In such embodiments, the divalent cation-containing aqueous solution or any solvent or solution for digestion of the metal-containing silicate material may be acidified. Acidification includes HF, HCl, HBr, HI, H ₂ SO ₄ , HNO ₃ , H ₃ PO ₄ , chromic acid, H ₂ CO ₃ , acetic acid, citric acid, formic acid, gluconic acid, lactic acid, oxalic acid, tartaric acid, It may be achieved by contact with either a weak or strong acid in gas, liquid (including aqueous solution), or solid form, including but not limited to ascorbic acid and meldrum acid. For example, in some embodiments, the metal-containing silicate material is digested in an acidic aqueous solution acidified with aqueous HCl that is from an electrochemical process. In such embodiments, the electrochemical process is a low voltage electrochemical process as described herein. In some embodiments, the metal-containing silicate material and / or other rocks and minerals of CO ₂ and waste gases (eg, combustion gases from the combustion of fossil fuels such as flue gas from coal-fired power plants). It is digested in an aqueous solution that has become acidic for the addition of other ingredients. The acidic solution was acidified to accelerate the digestion of material comprising metal silicates, may be sea water, wherein acidification is provided by bubbling gaseous CO ₂ in seawater, carbonate To produce seawater saturated with. In some embodiments, digestion of metal-containing silicate materials and / or other rocks and minerals is achieved over a pH range that includes pH 7.1 to pH 6.5, pH 6.5 to pH 6 0.0, pH 6.0 to pH 5.5, pH 5.5 to pH 5.0, pH 5.0 to pH 4.5, pH 4.5 to pH 4.0, pH 4.0 to pH 3.5, pH 3.5 to pH 3.0 PH 3.0 to pH 2.5, pH 2.5 to pH 2.0, pH 2.0 to pH 1.5, pH 1.5 to pH 1.0, pH 1.0 to pH 0.5, and pH 0.5 to pH 0.0. included. For example, in some embodiments, the digestion of the metal-containing silicate material is pH 7.1 to pH 6.0, pH 7.1 to pH 5.0, pH 6.0 to pH 4.0, pH 6.0 to pH 3.0, It is achieved at pH 6.0 to pH 2.0, or pH 5.0 to pH 0.0. For example, olivine may be digested with an aqueous solution having a pH ranging from pH 4.8 to pH 7.0, a pH resulting from dissolution of CO _{2 in} the aqueous solution. The proton scavenger is either in the SiO ₂ containing slurry or in the resulting solution (eg, containing Ca ²⁺ and Mg ²⁺ ) that remains after the SiO ₂ (and other silicon-based materials) are removed. It is added in the next step. Addition of a proton scavenger, if sufficient, can cause precipitation of precipitates containing carbonate (eg, CaCO ₃ , MgCO ₃ ). Those skilled in the art will recognize that certain acidification methods, such as the addition of aqueous carbonic acid or bubbling CO ₂ into a suspension of metal-containing silicate material, provide carbonate ions, which then precipitate as a carbonate-containing precipitate. You will fully understand that it is possible. In addition, those skilled in the art will recognize that the selection of a suitable acid for digestion, followed by a suitable proton scavenger for neutralization of the resulting acidic solution, may be useful for precipitates and final products. You will fully understand that it can be implemented. Selection of suitable acid and proton scavengers is also a certain ionicity that would otherwise need to be achieved using other methods (eg, rinsing to remove NaCl from the precipitate). The formation of chemical species can be avoided.

An aqueous solution comprising divalent cations (eg, alkaline earth metal cations such as Ca ²⁺ and Mg ²⁺ ), and optionally SiO ₂ , the divalent cation-containing solution is precipitating conditions (ie, eg, based on pH The CO ₂ source may be contacted at any point before, during, or after being subjected to conditions that allow for the precipitation of one or more materials. Thus, in some embodiments, an aqueous solution of divalent cations, and the aqueous solution, and carbonates, optionally, CO ₂ before subjecting to favor precipitation conditions for the formation of precipitate and a SiO ₂ Contact with source. In some embodiments, an aqueous solution of a divalent cation is contacted with a source of CO ₂ while subjecting the aqueous solution to precipitation conditions that favor the formation of a precipitate. In some embodiments, the aqueous solution of divalent cations is contacted with your appeal while CO ₂ source before subjecting to precipitation conditions favoring the formation of the aqueous solution precipitates. In some embodiments, an aqueous solution of a divalent cation is contacted with a CO ₂ source after subjecting the aqueous solution to precipitation conditions that favor the formation of a precipitate. For example, in some embodiments, an aqueous solution of a divalent cation is contacted with a proton scavenger to produce a slurry, which is then passed through a droplet generation system through a CO ₂ containing gas. Is introduced into a horizontal contact chamber containing See, for example, US Provisional Patent Application No. 61 / 223,657, filed July 7, 2009, the contents of which are incorporated herein by reference. In some embodiments, an aqueous solution of a divalent cation is contacted with a CO ₂ source before, during, or after subjecting the aqueous solution to precipitation conditions that favor the formation of a precipitate. In some embodiments, the divalent cation-containing aqueous solution may be circulated more than once, where the first cycle of precipitation primarily removes carbonate (eg, calcium carbonate, magnesium carbonate) and silicon-based material. Leaving an alkaline solution to which additional divalent cations may be added, where additional divalent cations are disclosed herein, including divalent cations from digestion of additional metal-containing silicate materials. May be added from any divalent cation source. Carbon dioxide, when brought into contact with the recycled solution containing a divalent cation, and carbonates, optionally, and a SiO _2, to allow precipitation of additional precipitate. In these embodiments, it is possible that the aqueous solution after the first cycle of precipitation may be contacted with the CO ₂ source before, during and / or after the divalent cation is added. It will be fully understood. In some embodiments, contacting the aqueous solution with a divalent cation of low concentration or not have any divalent cation and CO _2. In these embodiments, the aqueous solution may be recycled or newly introduced. Therefore, the order of CO ₂ addition and digestion of the metal-containing silicate material may vary. For example, metal-containing silicate materials such as serpentine, olivine, or wollastonite, each of which provides a divalent cation, SiO ₂ , or both, can be added to, for example, brine, seawater, or fresh water Well, this is followed by the addition of CO ₂ . In another example, CO ₂ may be added to, for example, brine, sea water, or fresh water, followed by the addition of a metal-containing silicate material.

A divalent cation-containing aqueous solution (optionally comprising SiO ₂ ) may be contacted with the CO ₂ source using any convenient protocol. When CO ₂ is a gas, contact protocols of interest include direct contact protocols (eg, bubbling CO ₂ gas into an aqueous solution), parallel contact methods (ie, unidirectional gas phase flow and liquid phase Contact between the flow), counter-current methods (ie, contact between the vapor and liquid phases flowing in opposite directions) and the like. Thus, contact can be accomplished by use of an injector, bubbler, fluid Venturi reactor, sparger, gas filter, spray, tray, or packed column reactor where convenient. In some embodiments, gas-liquid contact is accomplished by forming a liquid sheet of solution with a flat jet nozzle, where the CO ₂ gas and liquid sheet are in a countercurrent, cocurrent, or crossflow direction, Or move in any other suitable way. For example, US Provisional Patent Application No. 61 / 158,992, filed March 10, 2009, and each filed May 14, 2009, each of which is incorporated herein by reference in its entirety. U.S. Provisional Patent Application No. 61 / 178,475. In some embodiments, the gas-liquid contact is accomplished by spraying the precipitation reaction mixture precursor such that the contact is optimized between the precipitation reaction mixture precursor droplets and the CO ₂ source. . In some embodiments, the gas - liquid contact, such as 100 microns or less, the liquid droplets of a solution having an average diameter of less 500 microns, is accomplished by contacting the CO ₂ gas source. See, for example, US Provisional Patent Application No. 61 / 223,657, filed July 7, 2009, which is hereby incorporated by reference in its entirety. In some embodiments, a catalyst is used to accelerate the dissolution of carbon dioxide into the solution by accelerating the reaction towards equilibrium; the catalyst is an inorganic material such as zinc dichloride or cadmium, or It may be an organic substance such as an enzyme (for example, carbonic anhydrase).

In the method of the present invention, a volume of CO ₂ -filled solution produced as described above comprises a carbonate-containing precipitate and a supernatant (ie, a portion of the precipitation reaction mixture that remains above after precipitation of the precipitate). Sufficient carbonate compound precipitation conditions are applied to form. Any convenient precipitation conditions may be used that result in the formation of a carbonate-containing precipitate (optionally with SiO ₂ ) from the CO ₂ -filled precipitation reaction mixture. Precipitation conditions include those that adjust the physical environment of the CO ₂ filled precipitation reaction mixture to produce the desired precipitate. For example, the temperature of the CO ₂ -filled precipitation reaction mixture may be the desired carbonate-containing precipitate, or a component thereof (eg, sulfate resulting from CaSO ₄ , eg, a sulfur-containing gas in the combustion gas, or sulfate from seawater. ) To the point where precipitation occurs. In such embodiments, the temperature of the CO ₂ full precipitation reaction mixture may be raised to a value of 5 ° C. to 70 ° C., such as from 20 ° C. to 50 ° C., and including from 25 ° C. to 45 ° C. Although a given set of precipitation conditions has a temperature in the range of 0 ° C. to 100 ° C., this temperature may be raised in certain embodiments to produce the desired precipitate. In certain embodiments, the temperature of the precipitation reaction mixture is low or zero carbon dioxide emission sources (eg, solar energy source, wind energy source, hydropower energy source, waste heat from flue gas of carbon dioxide emitter, etc. ) Using the energy generated from. In some embodiments, the temperature of the precipitation reaction mixture may be increased utilizing heat from flue gas from coal or other fuel combustion. The pressure may also be modified. In some embodiments, the pressure for a given set of precipitation conditions is from standard atmospheric pressure (about 1 bar) to about 50 bar. In some embodiments, the pressure for a given set of precipitates is 1 to 2.5 bar, 1 to 5 bar, 1 to 10 bar, 10 to 50 bar, 20 to 50 bar, 30 to 50 bar. Or 40-50 bar. In some embodiments, precipitation of the precipitate is performed under ambient conditions (ie, standard atmospheric temperature and pressure). The pH of the CO ₂ full precipitation reaction mixture may also be raised to an amount suitable for precipitation of the desired carbonate-containing precipitate. In such embodiments, the pH of the CO ₂ filled precipitation reaction mixture is raised to an alkaline level for precipitation, where carbonate is advantageous over bicarbonate. The pH may be raised to pH 9 or higher, such as pH 10 or higher, including pH 11 or higher. For example, when a proton scavenger source such as fly ash is used to raise the pH of the precipitation reaction mixture or its precursor, the pH may be about pH 12.5 or higher.

  Thus, a set of precipitation conditions to produce the desired precipitate from the precipitation reaction mixture includes temperature and pH, and in some cases, additives and ionic chemistry in solution, as described above. Species concentration may be included. Precipitation conditions may also include factors such as mixing speed, form of agitation such as ultrasonic agitation, and the presence of seed crystals, catalysts, membranes, or substrates. In some embodiments, precipitation conditions include supersaturation conditions, temperature, pH, and / or concentration gradients, or cycling or changing any of these parameters. (From start [e.g. digestion of metal-containing silicate material] to end [e.g. drying of precipitate or formation of pozzolanic material from precipitate]) protocol used to produce carbonate-containing precipitates according to the present invention May be a batch, semi-batch, or continuous protocol. It will be appreciated that the precipitation conditions may be different to produce a given precipitate in a continuous flow system compared to a semi-batch or batch system.

The carbonate-containing precipitate is separated from the reaction mixture after formation from the precipitation reaction mixture to produce a separate precipitate (eg, wet cake) and a supernatant. The precipitate according to the invention may contain SiO ₂ ; if the silicon-based material is separated after digestion of the metal-containing silicate material, the precipitate contains very little SiO ₂ or contains SiO ₂ Does not contain at all. The precipitate may be stored in the supernatant for a period of time after precipitation and before separation (eg, by drying). For example, the precipitate may be stored in the supernatant at a temperature in the range of 1 ° C. to 40 ° C., such as 20 ° C. to 25 ° C., for a period in the range of 1 to 1000 days or more, such as 1 to 10 days or more. Good. Separation of the precipitate from the precipitation reaction mixture can be drained (eg, gravity sedimentation of the precipitate, subsequent drainage), decantation, filtration (eg, gravity filtration, vacuum filtration, filtration using forced air), centrifugation, squeezing , Or any combination thereof, is achieved using any of a number of convenient approaches. Separation of bulk water from the precipitate produces a wet cake of the precipitate, or a dehydrated precipitate. Epuramat's Extreme-Separator ("ExSep") solution, as detailed in U.S. Patent Application No. 61/170086, filed Apr. 16, 2009, incorporated herein by reference. -Use of liquid-solid separators such as solid separators, Xerox PARC spiral concentrators, or improvements of either Euramat's ExSep or Xerox PARC spiral concentrators; separation of precipitates from the precipitation reaction mixture I will provide a.

In some embodiments, the resulting dehydrated precipitate is then dried to produce a product (eg, cement, pozzolanic cement, or storage stable CO ₂ sequestered product). Drying may be accomplished by air drying the precipitate. When the precipitate is air dried, the air drying may be at a temperature in the range of -70 ° C to 120 ° C. In certain embodiments, drying is accomplished by freeze-drying (ie, lyophilization), the precipitate is frozen, the ambient pressure is reduced, and the frozen water in the precipitate is gasified. Sufficient heat is applied to sublimate directly. In yet another embodiment, the precipitate is spray dried to dry the precipitate, where the liquid containing the precipitate is converted into hot gas (eg, gaseous waste stream from a power plant). And the liquid feed is then pumped through the nebulizer to the main drying chamber and the hot gas is passed in cocurrent or countercurrent to the nebulizer. Depending on the particular drying protocol, the drying station (described in more detail below) may be arranged to allow the use of filtration elements, lyophilized structures, spray-dried structures, and the like. In certain embodiments, waste heat from a power plant or similar operation may be used to perform the drying process when appropriate. For example, in some embodiments, the aggregate is manufactured through the use of high temperatures (eg, from power plant waste heat), pressure, or combinations thereof.

After separation of the precipitate from the supernatant, the separated precipitate may be further processed as desired; the precipitate may simply be transported to a place for long-term storage, effectively sequestering CO _2. it can. For example, carbonate-containing precipitates may be transported and stored at long-term storage sites, for example, on the ground (as storage-stable CO ₂ sequestering material), underground, deep seas, and the like.

The resulting supernatant of the precipitation process, or the slurry of the precipitate, may also be treated as desired. For example, the supernatant or slurry may be returned to a divalent cation-containing aqueous solution source (eg, the ocean) or elsewhere. In some embodiments, the supernatant may be contacted with a CO ₂ source as described above to sequester additional CO ₂ . For example, in an embodiment where the supernatant is to be transferred to the ocean, the supernatant is contacted with a gaseous waste source of CO ₂ in a manner sufficient to increase the concentration of carbonate ions present in the supernatant. May be. As described above, the contacting may be performed using any convenient protocol. In some embodiments, the supernatant has an alkaline pH, and contact with the CO ₂ source reduces the pH to a range of pH 5-9, pH 6-8.5, or pH 7.5-8.2. Implemented in a sufficient manner.

In some embodiments, digesting the metal-containing silicate material with an aqueous solution to produce a divalent cation and a material comprising SiO ₂ , and dissolving the divalent cation with dissolved carbon dioxide to produce a precipitate. And a step of reacting is provided. In some embodiments, the method includes separating the precipitate from the supernatant with a liquid-solid separator, drying the precipitate, treating the precipitate to produce construction material, or Furthermore, the combination of is included. Thus, in some embodiments, the method further comprises separating the precipitate from the supernatant with a liquid-solid separator. In such embodiments, the liquid-solid separator is selected from liquid-solid separators that include baffle plates such as an Epuramat's Extreme-Separator ("ExSep") liquid-solid separator. For example, in some embodiments, the precipitate is separated from the precipitation reaction mixture by flowing the reaction mixture against the baffle, and the supernatant liquid deflects and separates from the precipitate particles upon striking the baffle. Collected by collectors. In some embodiments, the liquid-solid separator is selected from a liquid-solid separator including a spiral concentrator, such as a Xerox PARC spiral concentrator. For example, in some embodiments, the precipitate is separated from the precipitation reaction mixture by flowing the reaction mixture through a spiral channel that separates the particles of the precipitate from the supernatant and collecting the precipitate at an array at the outlet of the spiral channel. The In some embodiments, the method further comprises the step of drying the precipitate. In such embodiments, the precipitate may be dried to form a fine powder with a consistent particle size (ie, the precipitate has a relatively narrow particle size distribution). The precipitate may have Ca ²⁺ vs. Mg ²⁺ in the range of 1: 1000 to 1000: 1 as further described herein. Precipitates containing MgCO ₃ can include magnesite, ballonite, Neskehonite, Lance frightite, amorphous magnesium carbonate, altinite, hydromagnesite, or combinations thereof. Precipitates containing CaCO ₃ can include calcite, aragonite, vaterite, icite, amorphous calcium carbonate, monohydrocalcite, or combinations thereof. In some embodiments, the method further includes treating the precipitate to produce construction material. In such embodiments, the construction material is aggregate, cement, cementitious material, supplemental cementitious material, or pozzolanic.

FIG. 2 provides an embodiment of a method (100) for producing a precipitate comprising carbonate and SiO ₂ , which may be used as a pozzolanic material. The method (100) comprises a step (110) of contacting a mafic mineral with an acidic divalent cation-containing solution, and then a proton remover to the acidic divalent cation-containing solution used to contact the mafic mineral. Forming a precipitate containing carbonate and SiO ₂ by adding (120). Further, method 100, a pozzolanic material, comprising a step (130) to produce a precipitate containing a carbonate and a SiO _2.

As described above, metal-containing silicate materials (eg, rocks containing metal silicate minerals) have a wide range of initial particle sizes. Therefore, in this example, it is desirable to finely break the metal-containing silicate starting material, which is a mafic mineral. Crushing, grinding, sorting of mafic minerals, optional magnetic separation of the sorted mafic material, and optional heat treatment of the separated mafic material (eg, waste heat from flue gas), chemical It may be used for size reduction prior to processing (eg, chemical digestion). In some embodiments, the mafic mineral used in step 110 has a particle size of less than 500 μm or is reduced to that particle size to increase reactivity with the acidic divalent cation-containing solution. In step 110, a slurry comprising SiO ₂ is formed by contacting the mafic mineral with an acidic divalent cation-containing solution. The mafic mineral is a metal silicate containing magnesium and iron as described above, and the mineral includes olivine and serpentine, but is not limited thereto. The mafic mineral used in step 110 may be a mixture of such mafic minerals. The mafic mineral used in step 110 may also be used in combination with, for example, mafic rock (eg, basalt). Further, the mafic mineral used in step 110 is described in US patent application Ser. No. 12 / 486,692, filed Jun. 17, 2009, which is incorporated herein by reference in its entirety. As well as industrial process waste such as combustion ash, cement kiln dust, and / or slag.

In some embodiments, the mafic mineral is contacted with the divalent cation-containing solution while the solution is acidified, but in other cases, the divalent cation-containing solution includes the mafic mineral with this solution. Acidified prior to contact. For example, a column filled with mafic mineral may be contacted with the divalent cation-containing solution while a gas stream comprising CO ₂ is injected at the end of the same column as the divalent cation-containing solution. Similarly, an acidic solution (eg, HCl (aqueous)) may be injected at the end of the same column as the divalent cation-containing solution (with or without CO ₂ injection). Alternatively, the divalent cation-containing solution may be contacted with a gas stream comprising CO ₂ before contacting the divalent cation-containing solution with the mafic mineral. Similarly, the solid form or solution acid may be mixed with the divalent cation-containing solution prior to contacting the mafic mineral with the divalent cation-containing solution. Acidification of the divalent cation-containing solution may be similarly accomplished either before or during contact between the divalent cation-containing solution and the mafic mineral, where such contact may be in a tank or other reaction. Performed in a container.

Silica resulting from digestion of mafic minerals may exist, for example, as a colloidal suspension (eg, slurry) or gel. Silica may be partially amorphous or completely amorphous. In some embodiments, the silica resulting from digestion of the mafic mineral may be partially amorphous. In some embodiments, the silica resulting from digestion of the mafic mineral may be completely amorphous. Silica includes chemical species such as metasilicic acid (H ₂ SiO ₃ ), orthosilicic acid (H ₄ SiO ₄ ), disilicic acid (H ₂ Si ₂ O ₅ ), and / or pyrosilicic acid (H ₆ Si ₂ O ₇ ). It may be present as silicic acid or its conjugate base. Silicon species such as H ₃ SiO ₃ , H ₂ SiO ₃ , H ₄ SiO ₃ may also be present. In addition to silica, slurries produced by contact of divalent cation-containing solutions with mafic minerals can be found in silicates, carbonates, and various existing mafic minerals such as magnesium, aluminum, and iron cations. Potentially rich in cations. Small particles of the original mafic mineral and mafic mineral polymorphs may also be present.

  In some embodiments, the slurry produced in step 110 by digestion of the mafic mineral is treated to separate the silicon-based material from the divalent cation-containing solution. In such embodiments, it may be desirable to separate the silicon-based material since the highest concentration of silica may be achieved before the highest concentration of divalent cations such as, for example, magnesium. Such separation may be accomplished, for example, by agglomerating and / or otherwise sedimenting the silicon-based material in a sedimentation tank. Separation may also be accomplished by liquid-solid separation techniques such as, for example, centrifugation in a hydrocyclone.

A precipitate is formed in step 120 by raising the pH of the precipitation reaction mixture (with or without SiO ₂ ) to a level sufficient for precipitation of a precipitate containing carbonate (eg, MgCO ₃ , CaCO ₃ ). The In some embodiments, the precipitation reaction mixture, still containing the silicon-based material such as SiO _2. Thus, the precipitate formed in step 120 includes not only silicon-based materials, but also carbonates. In some embodiments, the silicon-based material is removed after the mafic mineral digestion at step 110. In such embodiments, the precipitate formed in step 120 includes carbonates with little or no silicon-based material. In either event, the proton scavenger is added to an acidic solution containing divalent cations to raise the pH to a level sufficient to cause precipitation of the precipitate. The proton scavenger may be a solid, a solid in solution, or a liquid. Solid proton scavengers include, for example, hydroxides such as KOH or NaOH. Such hydroxides may also be used in solution (eg, KOH (aqueous), NaOH (aqueous)). As described above, the proton remover can be a mafic mineral (eg, olivine, serpentine), combustion ash (eg, fly ash, bottom ash, boiler slag), or slag (eg, iron slag, phosphorus slag). Where the combustion ash and slag are US Provisional Patent Application No. 61 / 073,319, filed Jun. 17, 2008, the disclosure of which is hereby incorporated by reference in its entirety. It is further described in the specification. In some embodiments, the mafic mineral used in step 110 is also added as a proton scavenger in step 120. The pH of the divalent cation-containing solution may be raised to pH 7 to pH 12, pH 7 to pH 10, pH 7 to pH 9, or pH 7 to pH 8 in step 120. In some embodiments, the pH of the divalent cation-containing solution is raised to pH 13 or higher, such as pH 9 or higher, pH 10 or higher, pH 11 or higher, pH 12 or higher, or pH 14. In some embodiments, the step (120) of adding a proton scavenger to the divalent cation-containing solution uses a reaction vessel that is separate from the reaction vessel used in the mafic mineral dissolution step (110). Done. In some embodiments, both steps 110 and 120 are performed sequentially using the same reaction vessel. Alternatively, the protons are removed by an electrochemical process, such as a low voltage electrochemical process, as further described herein. An electrolysis process may also be used to raise the pH of the precipitation reaction mixture to a level sufficient for precipitation of the precipitate. Different electrolysis processes may be used, including a Castner-Kellner process, a diaphragm cell process, and a membrane cell process. Electroproduct by-products (eg, H ₂ , sodium metal) may be collected and used for other purposes. When a combination of proton scavengers is used, the proton scavengers may be used in any order. For example, a divalent cation-containing solution may already be basic (eg, seawater) before adding a proton scavenger, or a basic solution containing a proton scavenger may be added with an additional proton scavenger. May be further made basic. In any of these embodiments, CO ₂ is added before or after the proton scavenger, as described in more detail below.

As discussed in more detail below, the precipitate is a different mineral phase resulting from several mineral phases, for example coprecipitation processes adapted to yield a precipitate comprising calcium carbonate along with magnesium carbonate. May be included. The precipitation process is also adapted to result in a precipitate comprising a single mineral phase including but not limited to calcium carbonate, magnesium carbonate, calcium magnesium carbonate (eg, dolomite), or ferro-carbo-aluminosilicate. May be allowed. Different carbonate minerals may be precipitated sequentially. For example, a precipitate containing calcium carbonate is precipitated in one reactor under a first set of precipitation conditions, and a precipitate containing magnesium carbonate is precipitated in a second reactor under a second set of precipitation conditions. Also good. In another non-limiting example, a precipitate comprising magnesium carbonate may be precipitated prior to precipitation of a precipitate comprising calcium carbonate. In some embodiments, the precipitate is adapted to produce a precipitate that includes one or more hydroxide phases (eg, Ca (OH) ₂ , Mg (OH) ₂ ). The precipitate may be arranged to produce a precipitate in which both the carbonate and hydroxide phases present are completely or partially amorphous.

  Step 120 optionally includes adding a carbonate promoter to the precipitation reaction mixture. Examples of carbonate promoters include low concentrations of transition metals such as iron, cobalt, nickel, manganese, zinc, chromium, copper, barium, gold, platinum, or silver. Addition of iron (eg, iron chloride) to the precipitation reaction mixture in a sufficient amount increases the concentration of iron in the precipitation reaction mixture to within the range of about 0.001 parts per million (ppm) to about 500 ppm. there is a possibility. For example, iron is useful for promoting the formation of magnesium carbonate rather than the formation of magnesium hydroxide. Although the term “accelerator” is used herein, it will be appreciated that iron may not increase the rate of carbonate precipitation to such an extent that it suppresses the rate of hydroxide precipitation. . The carbonate promoter may be added to the precipitation reaction mixture either before the proton scavenger (or combination of proton scavengers) is added, or at any time before the start or completion of the precipitation.

Step 120 may optionally include adding additional reactants to the precipitation reaction mixture. For example, additional acid and proton scavengers may be added to stabilize the pH to the desired range. Selection of appropriate acid and proton scavengers may result in the addition of supplemental divalent cations such as Ca ²⁺ and Mg ²⁺ . In addition, the selection of appropriate acid and proton scavengers can result in the addition of supplemental anions such as CO ₃ ²⁻ that help to increase the yield of carbonate-containing precipitates. In some embodiments, a transition metal catalyst such as nickel is added to step 120 to induce the formation of larger particles during the precipitation process. In some embodiments, the pH is adjusted by bubbling CO ₂ into the precipitation reaction mixture and adding a proton scavenger (eg, a soluble hydroxide compound such as potassium hydroxide (KOH) or sodium hydroxide (NaOH)). Is cycled between pH 7 and pH 10.5.

  In some embodiments, the precipitation reaction mixture comprising a carbonate-containing precipitate is treated with a step for separating the carbonate-containing precipitate from the precipitation reaction mixture, leaving a supernatant, the supernatant being unused. May contain divalent cations. Such liquid-solid separation may be accomplished, for example, by agglomerating the precipitate and / or settling in a settling tank. Liquid-solid separation may also be achieved by liquid-solid separation techniques such as centrifugation. In embodiments where the silicon-based material from the digestion of the metal-containing silicate material is not separated from the divalent cation-containing solution (ie, step 140 is not performed), the precipitate is formed from the silicon-based material and carbonate (eg, carbonate Resulting in a mixture with magnesium, calcium carbonate). Step 120 may also include separating the precipitation mixture (ie, silicon- and carbonate-containing precipitates) from the precipitation reaction mixture.

In step 130, a pozzolanic material is produced from the material produced according to the method of FIG. In some embodiments, a precipitate comprising both SiO ₂ and carbonate is dried together to form a pozzolanic material. In some embodiments, when the silicon-based material is separated from the divalent cation-containing solution (optional step 140), the silicon-based material and the carbonate-containing precipitate are dried separately, then the pozzolanic material is Mixed to form. In some embodiments, the silicon-based material and the carbonate-containing precipitate are mixed when either one material or both are wet. In such embodiments, the subsequent wet blend material is then dried to produce a pozzolanic material. That any of the materials (eg, silicon-based materials, carbonate-containing precipitates, silicon- and carbonate-containing precipitates, wet-mixed pozzolanic materials) may optionally be washed with water before drying. It will be fully understood.

One drying method for various materials (eg, precipitates, wet mixed pozzolanic materials) is spray drying. In some embodiments, waste heat from an exhaust gas source (eg, flue gas from a coal-fired power plant) is used to spray dry precipitates or silicon-based materials. In some embodiments, CO ₂ from the same exhaust gas source is then used to acidify the divalent cation-containing solution (eg, as in step 110). Waste heat from exhaust gas entering the precipitation system at elevated temperatures can be obtained, for example, from US Provisional Patent Application No. 61 / 057,173, filed May 29, 2008, the disclosure of which is hereby incorporated by reference in its entirety. As described in the specification, it may be advantageously recovered during spray drying. Spray-dried material may have spherical particles or low aspect ratio shape, in some embodiments, at least 90% of the particles have a surface area of about 0.01 m ² / g to about ^{20 m} 2 / g And sized to be greater than about 0.5 μm and less than about 100 μm. In some embodiments, the dry particles are at least 75% 10 μm to 40 μm or 20 μm to 30 μm, such as about 0.75 to 3.0 m ² / g or 0.9 to 2.0 m ² / g. It is sized to have a surface area of 0.5-5 m ² / g.

  In some embodiments, the pozzolanic material is purified (ie, processed) prior to subsequent use. Purification may include any of a variety of different purification protocols. In some embodiments, the pozzolanic material is subjected to mechanical refining (eg, grinding, milling) to obtain a product with the desired physical properties (eg, particle size, surface area, etc.). In some embodiments, the pozzolanic material is combined with a hydraulic cement (eg, supplemental cementitious material, sand, aggregate, etc.). In some embodiments, one or more ingredients are added to the pozzolanic material to produce a final product (eg, concrete or mortar) (eg, when the pozzolanic material is to be used as a cement). Here, these components include, but are not limited to, sand, aggregate, and supplemental cementitious materials.

In some embodiments, the pozzolanic material produced by the methods disclosed herein is used as a construction material. To be used as construction materials, pozzolanic materials can be processed for use as construction materials, or buildings (eg, commercial, residential) and / or infrastructure (eg, roads, bridges, embankments, May be processed for use with existing construction materials (such as dams). Construction materials may be structural or non-structural components of such buildings and infrastructure. An additional benefit of using pozzolanic materials as or in construction materials is that the CO ₂ used in the method (eg, CO ₂ obtained from a gaseous waste stream) is effectively sequestered in the construction environment. Is Rukoto. In some embodiments, the precipitation system of the present invention may be installed at the same location as the building material plant so that the same location installation facilitates the processing of pozzolanic material into construction materials.

  In some embodiments, the pozzolanic material is utilized to produce aggregate. Such aggregates, methods for their production, and use of aggregates are described in co-pending US patent application Ser. No. 12/475, filed May 29, 2008, the disclosure of which is incorporated herein by reference in its entirety. , 378.

FIG. 3 illustrates an example system (700) for performing various methods as disclosed above. The metal silicate processing device 710, which receives the untreated metal-containing silicate material (240), has a size reduction unit for reducing the size of the metal-containing silicate material and a temperature for digesting the finely crushed metal-containing silicate material. Including a dipping device. This size reduction unit is for crushing, crushing (eg ball mill, jet mill etc.) and for selecting a finely divided metal-containing silicate material for subsequent digestion (eg by means of a sieve, a cyclone) May include any of a number of different devices. A digester is any other material that may be useful for digestion of metal-containing silicate materials, including but not limited to water and pH modifiers (eg, acids, proton scavengers, etc.) Together with the other material, arranged to receive the finely divided metal-containing silicate material. The processing apparatus may further include a filter configured to remove silica and / or silicon-based material from the digested metal-containing silicate material. A precipitation reaction vessel (210) operatively connected to the metal silicate processor (710) is configured to receive the digested metal-containing silicate material, or a slurry or aqueous solution thereof. In addition, the precipitation reaction vessel (210), CO 2 _(e.g., CO CO 2 that is hot or cool from industrial waste source comprising ₂₎ and, useful for preparing the precipitate or pozzolanic material of the present invention Configured to accept any other reagent (eg, acid, proton scavenger, accelerator) that may be The precipitation reaction vessel may be further arranged to adjust and control the precipitation reaction conditions. For example, the precipitation reaction vessel may have a temperature probe and a heating element, both of which can be used to control the temperature of the precipitation reaction mixture. As shown in FIG. 3, a liquid-solid separator (215) is operably connected to the precipitation reaction vessel (210) and is configured to receive the precipitation reaction mixture from the precipitation reaction vessel. The liquid-solid separator is further arranged to separate the precipitation reaction mixture into two streams, the streams comprising the supernatant and the precipitate. The resulting precipitate may be a relatively damp solid or slurry that is richer in precipitate than the original precipitation reaction mixture, either of which is a dry configured to accept the concentrated precipitate. A machine (720) may optionally be provided. A dryer (eg, spray dryer 220) that may accept waste heat from an industrial waste source of CO _{2 produced} a dried precipitate or pozzolanic material.

  FIG. 4 also illustrates an exemplary system (200) for performing the various methods disclosed above. System 200 includes a vertical column (205), a reaction vessel (210), a liquid-solid separator (215), and a spray dryer (220). The system (200) also includes an exhaust gas source (225), a divalent cation-containing solution source (230), and a proton remover source (235).

  The vertical column 205 may be filled with a metal-containing silicate material (240) as shown. In some embodiments, the metal-containing silicate material (240) has a particle size of about 500 μm or less. In some embodiments, the metal-containing silicate material (240) occupies approximately the bottom quarter of the vertical column (205). The vertical column (205) has at its bottom either a liquid inlet (245) for receiving a divalent cation-containing solution and either directly from the exhaust gas source (225) or from the spray dryer (220) as shown. And a gas inlet (250) for receiving exhaust gas therefrom. Although not shown in FIG. 4, the vertical column 205 and inlets 245 and 250 are valves, flow meters, temperature probes, and pH probes as needed to monitor and control the operation of the vertical column (205). It will be appreciated that other devices may be included. Similarly, the vertical column 205 is optionally modified for mechanical agitation in some embodiments.

The bottom of the vertical column is arranged (as shown) so that the divalent cation-containing solution and the exhaust gas containing CO ₂ enter the bottom of the vertical column 205 and mix (form carbonic acid and lower the pH). Also good. In some embodiments, a vertical column (205), the divalent cation-containing solution and a CO ₂ containing exhaust gas and the first accept mixing unit (not shown), the divalent cation-containing solution comprising metal silicates It further includes a mixing unit that serves to acidify the divalent cation-containing solution prior to encountering the material 240. The mixing unit may be integral with the bottom of the vertical column (205) or it may be disconnected from it. Regardless of the particular arrangement (ie, integral or disconnected), the mixing unit allows the acidified divalent cation-containing solution to permeate through the metal-containing silicate material 240 and the metal-containing silicate material ( 240) can be digested to form a silicon-based material slurry (optionally including smaller and / or unreacted metal-containing silicate material) to be operable in a vertical column It is attached. The vertical column 205 is modified to move the silicon-based material slurry up through the vertical column 205 in the same flow direction as the original divalent cation-containing aqueous solution. The vertical column 205 is further modified to degas the exhaust gas and to allow the slurry to exit the top of the column.

The exhaust gas degassed from the vertical column 205 is depleted of at least some of the CO ₂ gas originally present in the exhaust gas as received from the exhaust gas source (225). The CO ₂ depleted exhaust gas may be released directly into the atmosphere, further processed to remove other remaining components, or recovered for use in another part of the method. In some embodiments, the exhaust gas vented from the vertical column 205 is only in a concentration of one or more heavy metals, heavy metal compounds, particulate matter, sulfur compounds (eg, SOx), nitrogen compounds (eg, NOx), etc. In addition, the CO ₂ concentration is also impaired.

  After a sufficient amount of metallized silicate material (240) has been digested, the remaining metallized silicate material (240) in vertical column 205 is replaced with fresh metallized silicate material 240. In addition to providing a fresh charge of the metal-containing silicate material 240 to be digested, the replacement of the metal-containing silicate material (240) also ensures that insoluble contaminants are removed from the vertical column (205). enable. In some embodiments, insoluble material that is not removed can be incorporated into the resulting precipitate and ultimately as a filler into pozzolanic material or cement. Furthermore, as the metallized silicate material 240 is digested and the particle size is reduced, the rising divalent cation-containing solution tends to lift the particles from the packed bed portion of the vertical column (205). Thus, replacing the metal-containing silicate material (240) before the point of complete digestion addresses this problem equally well. A number of vertical columns (205) may be used in parallel to allow continuous operation of the system (200), where the divalent cation-containing solution and the exhaust gas stream are connected to several vertical columns (205). Is suspended for replenishment and switched from one vertical column (205) to another so that the other vertical column (205) is brought back online.

As illustrated in FIG. 4, the slurry produced in the vertical column (205) is then transferred to the reaction vessel 210. The slurry may be transferred by, for example, a pipeline. Proton remover from proton remover source 235 is added to the slurry in reaction vessel (210) to raise the pH of the slurry to produce a precipitate containing carbonate (eg, calcium carbonate, magnesium carbonate). . The precipitate will tend to settle with the silicon-based material on the bottom of the reaction vessel (210) in some embodiments. In some embodiments where the proton scavenger is in solution, the proton scavenger solution may be pumped to the reaction vessel (210). The solid form proton scavenger may be added, for example, by a conveyor belt. Although not shown in FIG. 4, the reaction vessel (210) is equipped with valves, flow meters, agitators, mixers, temperature probes, and pH as needed to monitor and control the operation of the reaction vessel (210). It will be appreciated that devices such as probes may be included. Also shown in FIG. 4 is any acid source that may be a gas (eg, carbon dioxide, HCl) or an acid in solution (eg, H ₂ CO ₃ (aqueous), HCl (aqueous)). Is not shown. The acid may be used to equilibrate the pH in the reaction vessel (210).

  In some embodiments, after the precipitate comprising silicon-based material and carbonate has been withdrawn from the reaction vessel (210), the precipitate is removed from the precipitation reaction mixture in a liquid-solid separator (215). To be separated. An exemplary liquid-solid separator (215) includes a hydrocyclone. The liquid removed by the liquid-solid separator (215) (ie, the supernatant liquid) can be disposed of or used for other industrial processes, including as an input for reverse osmosis water purification. Good.

  As illustrated in FIG. 4, the spray dryer 220 receives hot exhaust gas from a flue gas source (225), and silicon-based material and carbonates (eg, calcium carbonate) from a liquid-solid separator (215). , Magnesium carbonate) may be dried in a spray dryer 220, which optimizes energy efficiency. The precipitate dried in the spray dryer using waste heat from the flue gas source forms a fine powder with controlled particle size, aspect ratio, density and surface area, which powder is used as pozzolanic powder 255 May be. While the heat of the exhaust gas contributes to drying the precipitate in the spray dryer 220, the exhaust gas is thereby also cooled. Advantageously, the use of exhaust gas waste heat can reduce or obviate the need to heat air or some other gas prior to spray drying. In order to allow the cooled exhaust gas to be directed to the vertical column (205), the spray dryer 220 is placed in a sealed chamber (not shown) so that the exhaust gas leaving the spray dryer (220) is accommodated. It may be arranged.

The exhaust gas source (225) is, in some embodiments, a fossil fuel-fired power plant, a refinery, or, for example, filed May 29, 2008, the disclosure of which is hereby incorporated by reference in its entirety. Even other industrial processes that emit exhaust gases with high concentrations of CO ₂ relative to atmospheric CO ₂ , such as described in US Provisional Patent Application No. 61 / 057,173. Good. In some embodiments, such exhaust gas is produced by a combustion reaction, and therefore the exhaust gas has residual heat from the combustion reaction. If the distance from the exhaust gas source (225) is vast, or if the exhaust gas is otherwise not hot enough for spray drying purposes, a gas heating device (not shown) will adjust the temperature of the exhaust gas. It may be placed between the exhaust gas source (225) and the spray dryer (220) for raising. In addition to the oxidizing exhaust gas generated by combustion, the exhaust gas source (225) may be replaced with a reducing gas source such as synthesis gas, shifted synthesis gas, natural gas, hydrogen, etc., as long as the reducing gas contains CO _2. The good will be well understood. Other suitable multi-component gas streams include turbocharged boiler product gas, coal gasification product gas, shift coal gasification product gas, anaerobic digester product gas, wellhead natural gas stream, reformed natural gas or methane Includes hydrates.

  The divalent cation-containing solution source (230) may in some embodiments be a storage tank that may be filled with seawater, brine, or some other divalent cation-containing solution as described above. The storage tank allows contaminants such as silt, sand, small rocks, and other particulate matter to settle out of the divalent cation containing solution before the divalent cation containing solution is introduced into the vertical column (205). Also good. A filter may also be used.

  FIG. 5 shows an optional source of promoter (310) that may be used to add carbonate promoter to reaction vessel (210). As discussed above, exemplary carbonate promoters include low concentrations of transition metals such as iron, cobalt, nickel, manganese, zinc, chromium, copper, barium, gold, platinum, or silver. However, it is not limited to them. Accelerator source (310) may include a regulator (not shown) for controlled release of carbonate promoter into reaction vessel (210). A feedback system (not shown) may be used to monitor the concentration of carbonate promoter in the reaction vessel (210) and adjust the regulator accordingly.

  FIG. 6 shows an optional liquid-solid separator (410) placed between the vertical column (205) and the reaction vessel (210). The liquid-solid separator (410) receives the slurry from the vertical column and separates the silicon-based material (eg, silica, unreacted or undigested silicate, etc.) from the divalent cation-containing solution and contains the divalent cation. The solution is led to the reaction vessel (210). The silicon-based material that is removed from the liquid-solid separator (410) is sometimes referred to as a wet cake. Also shown in FIG. 6 is a washer 420 for cleaning silicon-based material, which receives the wash water and silicon-based material from the liquid-solid separator (410). The washer (420) removes soluble salts to produce a cleaned silicon-based material and used wash water. The silicon-based material removed from the washer (420) may then be dried to produce a fine silicon-based powder. In some embodiments, the liquid-solid separator (410) and the washer (420) are combined into a single unit. In the system (200) for the washer (420) to receive and wash the precipitate comprising carbonate and silicon-based material from the liquid-solid separator (215) before the spray dryer (220). It will be appreciated that it may also be included.

  FIG. 7 illustrates a system 200 in which the second reaction vessel (510) receives supernatant from the liquid-solid separator (215) and additional proton remover from the proton remover source (235). In this embodiment, the conditions in the reaction vessel (210) are controlled to produce a first carbonate-containing precipitate that is separated from the precipitation reaction mixture with a liquid-solid separator (215). . The supernatant from the liquid-solid separator (215) is made more basic, for example by adding further proton scavengers from the proton scavenger source (235) to form a second carbonate-containing precipitate. The The second precipitate is then separated from the precipitation reaction mixture in a second liquid-solid separator (520). The first and second carbonate-containing precipitates may be washed separately, as in FIG. 6, and then spray dried separately to produce two fine powders. These powders may then be mixed with a powder of silicon-based material to produce a pozzolanic material (FIG. 6). In some embodiments, the first carbonate-containing precipitate comprises calcium carbonate and the second carbonate-containing precipitate comprises magnesium carbonate, while in other embodiments, the first carbonate-containing precipitate is magnesium carbonate. And the second carbonate-containing precipitate contains calcium carbonate.

It will be appreciated that a carbonate promoter may be added to either or both of the reaction vessels (210, 510) illustrated in FIG. If carbonate promoters are added to both reaction vessels (210, 510), different carbonate promoters may be used, or different concentrations of the same carbonate promoter may be used. Further, FIG. 7 shows the second reaction vessel (510) as receiving a proton remover from the same proton remover source (235) as the reaction vessel 210 serves, although in some embodiments The second reaction vessel (510) then receives a different proton remover from the second proton remover source. Still further, in some embodiments, the supernatant received in the second reaction vessel (510) is made more acidic rather than more basic to produce a second carbonate-containing precipitate. As mentioned above, acidification may be achieved by contact with a gas stream comprising CO ₂ or by addition of an acidic solution or a soluble solid acid. Furthermore, in addition to or in place of maintaining different pH levels in the reaction vessels (210, 510) and using different carbonate promoters, such as temperature, pressure, the presence of certain seed crystals, etc. Other conditions may be varied to form different carbonate-containing precipitates in the two reaction vessels (210, 510).

Compositions and Final Products The precipitates of the present invention may contain several carbonates and / or several carbonate mineral phases resulting from coprecipitation, where the precipitate is, for example, magnesium carbonate (eg, Calcium carbonate (eg, calcite) may be included together with (Neskehon stone). Precipitates also include, but are not limited to, calcium carbonate (eg, calcite), magnesium carbonate (eg, Neskehonite), calcium carbonate (eg, dolomite), or ferro-carbo-aluminosilicate. Single carbonates in the mineral phase may be included. Since different carbonates can precipitate in sequence, the precipitate is relatively rich in monocarbonate and / or monomineral phase (eg, 90% -95% depending on the conditions from which it is obtained). ) Or substantially enriched (e.g., 95% to 99.9%), or the precipitate may contain an amount of other carbonates and / or other mineral phases, where desired The mineral phase is 50-90% of the precipitate. It is well understood that in some embodiments, the precipitate may include one or more hydroxides (eg, Ca (OH) ₂ , Mg (OH) ₂ ) in addition to the carbonate. Will. It will also be appreciated that any carbonate or hydroxide present in the precipitate may be completely or partially amorphous. In some embodiments, the carbonate and / or hydroxide is completely amorphous.

Although many different carbon-containing salts and compounds are possible due to the variety of starting materials, precipitates containing magnesium carbonate, calcium carbonate, or combinations thereof are particularly useful. In some embodiments, the precipitate is a carbonate mineral that includes both calcium and magnesium, dolomite (CaMg (CO ₃ ) ₂ ), protodolomite, huntite (CaMg ₃ (CO ₃ ) ₄ ). , And / or Sergeybite (Ca ₂ Mg ₁₁ (CO ₃ ) ₁₃ .H ₂ O). In some embodiments, the precipitate comprises calcium carbonate in one or more phases selected from calcite, aragonite, vaterite, or combinations thereof. In some embodiments, precipitation material, Aikaito _{(CaCO 3 · 6H 2 O)} , amorphous calcium carbonate _{(CaCO 3 · nH 2 O)} , monohydrocalcite _{(CaCO 3 · H 2 O)} , or their A hydrated form of calcium carbonate selected from the combination of: In some embodiments, the precipitate comprises magnesium carbonate without water of hydration. In some embodiments, the precipitate comprises magnesium carbonate having any of a number of different hydration waters selected from 1, 2, 3, 4, or more than four hydration waters. In some embodiments, the precipitate comprises 1, 2, 3, 4, or more than 4 different magnesium carbonate phases, where the magnesium carbonate phase differs in the number of hydration waters. For example, precipitation material, magnesite (MgCO _3), Barintonaito _{(MgCO 3 · 2H 2 O)} , nesquehonite _{(MgCO 3 · 3H 2 O)} , Lance folder site _{(MgCO 3 · 5H 2 O)} , and amorphous May contain high quality magnesium carbonate. In some embodiments, the precipitate is altinite (MgCO ₃ .Mg (OH) ₂ .3H ₂ O), hydromagnesite (Mg ₅ (CO ₃ ) ₄ (OH) ₂ .3H ₂ O), or Includes magnesium carbonate including hydroxide and hydrated water, such as combinations thereof. Thus, the precipitate may include carbonates of calcium, magnesium, or combinations thereof in all or some of the various states of hydration listed herein. The precipitation rate can also affect the nature of the precipitate, with the fastest precipitation rate being achieved by seeding the solution with the desired phase. Without seeding, fast precipitation may be achieved, for example, by rapidly raising the pH of the precipitation reaction mixture, which results in more amorphous components. Furthermore, the higher the pH, the faster the precipitation and the precipitation results in a more amorphous precipitate.

Adjusting the major ion ratio throughout precipitation can affect the nature of the precipitate. The major ion ratio has a considerable effect on polymorph formation. For example, as the magnesium: calcium ratio in water increases, aragonite becomes the major polymorph of calcium carbonate in the precipitate rather than low magnesium calcite. At low magnesium: calcium ratios, low magnesium calcite becomes the major polymorph. In some embodiments, when both Ca ²⁺ and Mg ²⁺ are present, the ratio of Ca ²⁺ to Mg ^{2+ in} the precipitate (ie, Ca ²⁺ : Mg ²⁺ ) is 1: 1 to 1: 2.5. 1: 2.5 to 1: 5; 1: 5 to 1:10; 1:10 to 1:25; 1:25 to 1:50; 1:50 to 1: 100; 1: 100 to 1: 150 1: 150-1: 200; 1: 200-1: 250; 1: 250-1: 500; 1: 500-1: 1000, or a range thereof. For example, in some embodiments, the ratio of Ca ²⁺ to Mg ^{2+ in} the precipitate is from 1: 1 to 1:10; 1: 5 to 1:25; 1:10 to 1:50; 1: 100; 1:50 to 1: 500; or 1: 100 to 1: 1000. In some embodiments, the ratio of Ca ²⁺ to Mg ^{2+ in} the precipitate (ie, Ca ²⁺ : Mg ²⁺ ) is 1: 1 to 1: 2.5; 1: 2.5 to 1: 5; 1 1: 5 to 1:10; 1:10 to 1:25; 1:25 to 1:50; 1:50 to 1: 100; 1: 100 to 1: 150; 1: 150 to 1: 200; 1: 200 ~ 1: 250; 1: 250-1: 500; 1: 500-1: 1000, or a range thereof. For example, in some embodiments, the ratio of Ca ²⁺ to Mg ^{2+ in} the precipitate is from 1: 1 to 1:10; 1: 5 to 1:25; 1:10 to 1:50; 1: 100; 1:50 to 1: 500; or 1: 100 to 1: 1000.

The precipitate, which contains one or more synthetic carbonates derived from industrial CO ₂ , is a fossil fuel (eg, coal, oil, natural gas, or smoke) from which industrial CO ₂ (from combustion of fossil fuels) is derived. It reflects the relative carbon isotope composition (δ ¹³ C) of the road gas. The relative carbon isotope composition (δ ¹³ C) value in units of ‰ (permil) is the value of the two stable isotopes of carbon, the ¹² C and ¹³ C, relative to the fossilized aragonite standard (PDB standard). It is a measure of concentration ratio.
δ ¹³ C ‰ = [( ¹³ C / ¹² C _sample − ¹³ C / ¹² C _{PDB standard} ) / ( ¹³ C / ¹² C _{PDB standard} )] × 1000

Thus, δ ¹³ C of the synthetic carbonate-containing precipitate serves as a fingerprint for the CO ₂ gas source. Although the δ ¹³ C value can vary from source to source (ie, fossil fuel source), the δ ¹³ C value for the compositions of the present invention is generally but not necessarily in the range of -9 ‰ to -35 ‰. It is. In some embodiments, the δ ¹³ C values for the synthetic carbonate-containing precipitates are −1 ‰ to −50 ‰, −5 ‰ to −40 ‰, −5 ‰ to −35 ‰, −7 ‰ to − 40 ‰, -7 ‰ to -35 ‰, -9 ‰ to -40 ‰, or -9 ‰ to -35 ‰. In some embodiments, the δ ¹³ C value for the synthetic carbonate-containing precipitate is −3 ‰, −5 ‰, −6 ‰, −7 ‰, −8 ‰, −9 ‰, −10 ‰, − 11 ‰, -12 ‰, -13 ‰, -14 ‰, -15 ‰, -16 ‰, -17 ‰, -18 ‰, -19 ‰, -20 ‰, -21 ‰, -22 ‰, -23 ‰ , -24 ‰, -25 ‰, -26 ‰, -27 ‰, -28 ‰, -29 ‰, -30 ‰, -31 ‰, -32 ‰, -33 ‰, -34 ‰, -35 ‰,- Less than 36 ‰, -37 ‰, -38 ‰, -39 ‰, -40 ‰, -41 ‰, -42 ‰, -43 ‰, -44 ‰, or -45 ‰ (ie more negative) The more negative the δ ¹³ C value, the richer the synthetic carbonate-containing composition is ¹² C. Any suitable method, including, but not limited to, mass spectrometry or off-axis integrated-cavity output spectroscopy (off-axis ICOS) may be used to obtain a δ ¹³ C value. It may be used to measure.

  In addition to the magnesium- and calcium-containing products of the precipitation reaction, compounds and materials including silicon, aluminum, iron, and others can also be produced and incorporated into the precipitate with the methods and systems of the present invention. There is sex. Precipitation of such compounds in the precipitate may be desirable to alter the reactivity of the cement containing the precipitate resulting from the process or to change the properties of the hardened cement and the concrete made therefrom. Metal-containing silicate materials are used to produce carbonate-containing precipitates containing one or more components such as amorphous silica, amorphous aluminosilicate, crystalline silica, calcium silicate, calcium alumina silicate, etc. Is added to the precipitation reaction mixture as one source of the components. In some embodiments, the precipitate is from 1: 1 to 1: 1.5; 1: 1.5 to 1: 2; 1: 2 to 1: 2.5; 1: 2.5 to 1: 3. 1: 3 to 1: 3.5; 1: 3.5 to 1: 4; 1: 4 to 1: 4.5; 1: 4.5 to 1: 5; 1: 5 to 1: 7.5 1: 7.5 to 1:10; 1:10 to 1:15; 1:15 to 1:20, or carbonates (eg, calcium carbonate, magnesium carbonate) in a carbonate: silica ratio in these ranges. Including silica. For example, in some embodiments, the precipitate comprises carbonate and silica in a carbonate: silica ratio of 1: 1 to 1: 5, 1: 5 to 1:10, or 1: 5 to 1:20. Including. In some embodiments, the precipitate is from 1: 1 to 1: 1.5; 1: 1.5 to 1: 2; 1: 2 to 1: 2.5; 1: 2.5 to 1: 3. 1: 3 to 1: 3.5; 1: 3.5 to 1: 4; 1: 4 to 1: 4.5; 1: 4.5 to 1: 5; 1: 5 to 1: 7.5 1: 7.5 to 1:10; 1:10 to 1:15; 1:15 to 1:20, or a range of silica: carbonate ratios of silica and carbonate (eg, calcium carbonate, magnesium carbonate) ). For example, in some embodiments, the precipitate comprises silica and carbonate at a silica: carbonate ratio of 1: 1 to 1: 5, 1: 5 to 1:10, or 1: 5 to 1:20. Including. In general, the precipitate produced by the method of the present invention comprises a mixture of a silicon-based material and at least one carbonate phase. In general, the faster the reaction rate, the more silica will be carbonated, provided that silica is present in the precipitation reaction mixture (ie, the silica was not removed after digestion of the metal-containing silicate material). Incorporated into the salt-containing precipitate.

The precipitate (which may simply be a dried precipitate) can be in a storage stable form, for a long period of time, for example 1 year or more, 5 years or more, 10 years or more, 25 years or more, 50 years or more Over 100 years, over 250 years, over 1000 years, over 10,000 years, over 1,000,000 years, or even over 100,000,000 years, if any, exposed without noticeable degradation It may be stored on the ground under conditions (ie open to the atmosphere). The storage-stable form of the precipitate is subject to little degradation, if any, while stored on the ground under normal rainwater pH, so as measured in terms of CO ₂ gas emissions from the product, If any, the amount of degradation will not exceed 5% / year, and in some embodiments will not exceed 1% / year. The above-ground stable form of the precipitate is stable under a variety of different environmental conditions, for example at temperatures ranging from -100 ° C to 600 ° C and humidity ranging from 0 to 100%, where these conditions are mild May be windy or stormy. Physically suitable for determining that a compound in a precipitate is similar or identical to a naturally occurring compound known to have the stability specified above (eg, limestone) Any of a number of suitable methods, including test methods and chemical test methods, may be used to test the stability of the precipitate.

Carbonate-containing precipitates that serve to sequester CO ₂ in a form that is stable over a long period of time (eg, geologic age scale) can be stored for a long period of time as described above. If the precipitate is required to achieve a certain ratio of carbonate to silica, a silicon-based material (eg, isolated silicon after digestion with a metal-containing silicate material) to form a pozzolanic material. It may also be mixed with a base material (such as commercially available SiO ₂ ). The pozzolanic material of the present invention, when combined with an alkali such as calcium hydroxide (Ca (OH) ₂ ), exhibits siliceous or aluminosilicic properties that show cementitious properties by forming calcium silicates and other cementitious materials. Material. SiO ₂ -containing materials such as volcanic ash, fly ash, silica fume, highly reactive metakaolin, and ground granulated blast furnace slag may be used to strengthen the pozzolanic material of the present invention. In some embodiments, the pozzolanic material of the present invention is 0.5% to 1.0%, 1.0% to 2.0%, 2.0% to 4.0%, 4.0% to 6%. 0.0%, 6.0% to 8.0%, 8.0% to 10.0%, 10.0% to 15.0%, 15.0% to 20.0%, 20.0% to 30 .0%, 30.0% 40.0%, is enhanced 40.0% to 50.0%, or SiO ₂ containing material in the range of their overlap.

  Spray dried materials (eg, precipitates, silicon-based materials, pozzolanic materials, etc.) can have a consistent particle size thanks to spray drying (ie, spray dried materials have a relatively narrow particle size distribution). be able to). Thus, in some embodiments, at least 50%, 60%, 70%, 80%, 90%, 95%, 97%, or 99% of the spray-dried material is ± 10 microns of a given average particle size , ± 20 microns, ± 30 microns, ± 40 microns, ± 50 microns, ± 75 microns, ± 100 microns, or ± 250 microns. In some embodiments, the given average particle size is 5 to 500 microns. In some embodiments, the given average particle size is 50 to 250 microns. In some embodiments, the given average particle size is between 100 and 200 microns. For example, in some embodiments, at least 70% of the spray-dried material falls in the range of ± 50 microns of a given average particle size, where the given average particle size is 50-250 microns, or 100- 5 to 500 microns, such as 200 microns.

  In general, pozzolanic materials have lower cementitious properties than ordinary Portland cement, but in the presence of a lime rich medium such as calcium hydroxide, it has better cementitious properties with respect to late strength (> 28 days) Indicates. The pozzolanic reaction may be slower than the rest of the reaction that occurs during cement hydration, and thus the short-term strength of concrete containing the pozzolanic material of the present invention may not be as high as concrete made with pure cementitious materials. . This indication mechanism of strength is the reaction of silicate and lime to form a secondary cementitious phase (lower calcium silicate hydrate with a lower C / S ratio), usually showing gradual strengthening properties after 7 days. . The degree of strength growth ultimately depends on the chemical composition of the pozzolanic material. Increasing the composition of silicon-based materials, particularly amorphous silicon-based materials (with optionally added silica and / or alumina) generally produces better pozzolanic reactions and strengths. Highly reactive pozzolans, such as silica fume and highly reactive metakaolin, can produce “early strong” concrete that increases the rate at which the concrete containing the precipitate of the present invention gains strength.

  Precipitates containing silicates and aluminosilicates can easily be used in the cement and concrete industry as pozzolanic materials thanks to the presence of finely divided siliceous and / or aluminosilicate materials (eg silicon-based materials) is there. The siliceous and / or aluminosilicic precipitates may be blended with Portland cement or added directly as a mineral admixture in the concrete mixture. In some embodiments, the pozzolanic material is calcium and magnesium in a ratio (as described above) that completes the setting time, setting, and long-term stability of the resulting hydration product (eg, concrete). Including. The carbonate crystallinity, the concentration of chloride, sulfate, alkali, etc. in the precipitate may be controlled for better contact with Portland cement. In some embodiments, the precipitate is 10-20%, 20-30%, 30-40%, 40-50%, 50-60%, 60-70%, 70-80%, 80-80% of silica. 90%, 90-95%, 95-98%, 98-99%, 99-99.9% include silica having a particle size (e.g., in the longest dimension) of less than 45 microns. In some embodiments, the siliceous precipitate is 10-20%, 20-30%, 30-40%, 40-50%, 50-60%, 60-70%, 70-80% of the aluminosilica. 80-90%, 90-95%, 95-98%, 98-99%, 99-99.9% include aluminosilica having a particle size of less than 45 microns. In some embodiments, the siliceous precipitate is 10-20%, 20-30%, 30-40%, 40-50%, 50-60%, 60-70%, 70-80% of the mixture, 80-90%, 90-95%, 95-98%, 98-99%, 99-99.9% include a mixture of silica and aluminosilica having a particle size (e.g., at the largest dimension) of less than 45 microns .

The pozzolanic material produced by the methods disclosed herein may be used as a construction material, which may be processed for use as a construction material or a building (eg, commercial, residential) And / or for use with existing construction materials for infrastructure (eg paved roads, roads, bridges, overpasses, walls, dikes, dams, etc.). Construction materials are incorporated into any structures, structures that further include foundations, parking lots, houses, office buildings, commercial offices, public buildings, and support structures (eg, gate footings, fences and poles) Well, it is considered part of the construction environment. Construction materials can be structural or non-structural components of such structures. An additional benefit of using pozzolanic materials as or in construction materials is that the CO ₂ used in the method (eg, CO ₂ obtained from a gaseous waste stream) is effectively sequestered in the construction environment. Is Rukoto.

  In some embodiments, the pozzolanic material of the present invention is used as a component of a hydraulic cement (eg, ordinary Portland cement) that solidifies and hardens after being combined with water. Solidification and hardening of the product produced by combining the precipitate with cement and water is a hydrate formed from cement upon reaction with water and is essentially insoluble in water Occurs as a result of the generation of Such hydraulic cements, methods for their production and use are described in co-pending US patent application Ser. No. 12 / 126,776, filed May 23, 2008, the disclosure of which application is incorporated herein by reference. It is described in the book. In some embodiments, the pozzolanic material blended with the cement is 0.5% to 1.0%, 1.0% to 2.0%, 2.0% to 4.0% by weight, 4. 0% to 6.0%, 6.0% to 8.0%, 8.0% to 10.0%, 10.0% to 15.0%, 15.0% to 20.0%, 20. 0 to 30.0%, 30.0% to 40.0%, 40.0% to 50.0%, 50% to 60%, or a range of pozzolanic materials. For example, in some embodiments, the pozzolanic material blended with the cement is 0.5% to 2.0%, 1.0% to 4.0%, 2.0% to 8.0% by weight, 4.0% to 15.0%, 8.0% to 30.0%, or 15.0% to 60.0% pozzolanic material.

  In some embodiments, the pozzolanic material is blended with other cementitious materials or mixed into the cement as a mixture or aggregate. The mortar of the present invention has applications for tying construction blocks (eg, bricks) together and filling gaps between construction blocks. The mortar of the present invention may also be used to repair an existing structure (eg, to replace a damaged or corroded portion of the original mortar).

  In some embodiments, the pozzolanic material may be utilized to produce aggregate. In some embodiments, the aggregate is made from the precipitate by pressing and subsequent crushing. In some embodiments, the aggregate is made from the precipitate by extrusion and crushing the resulting extruded material. Such aggregates, their method of manufacture and use are described in co-pending US patent application Ser. No. 12 / 475,378, filed May 29, 2009, the disclosure of which is hereby incorporated by reference in its entirety. Are listed.

  The following examples are presented to provide one of ordinary skill in the art with a complete disclosure and description of how to make and use the invention and are not intended to limit the scope of the invention. Efforts have been made to ensure accuracy with respect to numbers used (eg amounts, temperature, etc.) but some experimental errors and deviations should be accounted for. Unless indicated otherwise, parts are parts by weight, molecular weight is weight average molecular weight, temperature is in degrees Celsius (° C.), and pressure is at or near atmospheric.

Example 1. Analytical instruments and methods Coulometric analysis: Acidification of liquid and solid carbon-containing samples with 2.0 N perchloric acid (HClO ₄ ) to release carbon dioxide into the carrier gas stream, followed by 3% w / v at pH 3.0 Any released sulfur gas was removed by gas scrubbing with silver nitrate before analysis with an inorganic carbon coulometer (UIC Inc, model CM5015). Cement, fly ash, and seawater samples are heated after the addition of perchloric acid in a heating block to assist in digestion of the samples.

Brunauer-Emmett-Teller ("BET") specific surface area: Specific surface area (SSA) measurements were by surface absorption with dinitrogen (BET method). The SSA of the dried samples was measured with a Micromeritics Tristar ^™ II 3020 Specific Surface Area and Possitivity Analyzer after the samples were prepared with a Flowprep ^™ 060 sample degassing system. Briefly, sample preparation involves degassing approximately 1.0 g of a dry sample at an elevated temperature while exposed to a stream of dinitrogen gas to remove residual water vapor and other adsorbents from the sample surface. It is. The purge gas in the sample holder was then evacuated and the sample was cooled before being exposed to dinitrogen gas at a series of increasing pressures (relative to the adsorption film thickness). After the surface was covered, dinitrogen was released from the surface of the particles by a systematic drop in pressure in the sample holder. The desorbed gas was measured and converted to a total surface area measurement value.

  Particle size analysis (“PSA”): Particle size analysis and particle size distribution were measured using static light scattering. Dry particles were suspended in isopropyl alcohol and analyzed using a Horiba Particle Size Distribution Analyzer (Model LA-950V2) in a dual wavelength / laser configuration. Using Mie scattering theory, a population of particles was calculated from 0.1 mm to 1000 mm as a function of size fraction.

Powder X-ray diffraction (“XRD”): Powder X-ray diffraction was performed on a Rigaku Miniflex ^™ (Rigaku) to identify crystalline phases and estimate the mass fraction of different identifiable sample phases. The dried solid sample was manually ground into a fine powder and loaded into a sample holder. The X-ray source was a copper anode (Cu kα) operating at 30 kV and 15 mA. X-ray scanning was performed over 5-90 ° 2θ at a scan rate of 2 ° 2θ / min and a step size of 0.01 ° 2θ / step. X-ray diffraction profiles were analyzed by Rietveld refinement using X-ray diffraction pattern analysis software Jade ^™ (version 9, Materials Data Inc. (MDI)).

Fourier Transform Infrared (“FT-IR”) Spectroscopy: FT-IR analysis was performed on a Nicolet 380 equipped with a Smart Diffuse Reflectance module. All samples were weighed to 3.5 ± 0.5 mg, manually ground with 0.5 g KBr, then pressed and purged with nitrogen for 5 minutes before being inserted into the FTIR. The spectrum was recorded in the range 400-4000 cm ⁻¹ .

Scanning Electron Microscopy (“SEM”): SEM was performed using a Hitachi TM-1000 tungsten filament tabletop microscope with a constant acceleration voltage of 15 kV at an operating pressure of 30-65 Pa, and a single BSE semiconductor detector. . The solid sample was secured to the stage using a carbon-based adhesive; the wet sample was vacuum dried to a graphite stage prior to analysis. EDS analysis is performed using the Oxford Instruments SwitchED-TM system, for which the sensor has a detection range of ¹¹ Na to ⁹² U with an energy resolution of 165 eV.

  Soluble Chloride: Chloride concentration was measured with a Chloride QuanTab® Test Strips (Product No. 2751340) with a test range of 300-6000 mg chloride per liter solution measured in 100-200 ppm increments.

  X-ray fluorescence ("XRF"): XRF analysis of a solid powder sample was performed using a Thermo Scientific ARL QUANT'X Energy-Dispersive XRF spectrometer equipped with a silver anode X-ray source and a Peltier cooled Si (Li) X-ray detector. Done using. The sample was pressed into 31 mm pellets using an aluminum sample cup. For each sample, three different spectra were collected, each adjusted for specific elemental analysis: all under vacuum conditions, the first using 4 kV and no X-ray filter, the second 18 kV. A thin silver filter was used, and the third was a 30 kV thick silver filter. The spectra were analyzed using WinTrace software using Fundamental Parameters (basic parameters) analysis method obtained from calibration with certified reference materials.

  Thermogravimetric analysis ("TGA"): TGA analysis of solid powder samples was performed on a TA Instruments SDT Q600 with simultaneous TGA / DSC (Differential Scanning Calorimetry). Samples in an alumina crucible were placed in a furnace heated from room temperature to 1000 ° C. at a constant ramp rate of 20 ° C./min. Weight loss profiles over temperature were analyzed using Universal Analysis software.

Example 2: Digestion of Olivine Summary: Olivine was digested with acid.

  Metallic silicate material: Olivine having an average particle size of 54.3 μm was obtained from Oliveline Corp (Bellingham, WA). The olivine fraction was reduced to an average particle size of 5.82 μm using a jet mill.

  Method: Olivine digestion is carried out by stirring olivine into 10% HCl (aqueous) (5.54 g olivine (54.3 μm) into 419.37 g 10% HCl) with stirring. Achieved at room temperature (20-23 ° C.). Olivine was leached for 4 days before measuring the concentration of aqueous magnesium by potentiometric EDTA titration.

Results and Observation: The concentration of Mg ²⁺ was measured by an experiment by EDTA titration using a calcium ion selective electrode. Experiments on olivine resulted in a Mg ²⁺ concentration of 0.1564 M after 4 days of leaching.

Example 3 Serpentine digestion Abstract: Serpentine was digested with acid.

  Metal-containing silicate material: Serpentine was obtained from KC Mining (King City, CA).

  Method: Serpentine digestion is performed at room temperature (20-23 ° C.) by stirring the serpentine into 10% HCl (aqueous) (5.03 g serpentine into 415.32 g 10% HCl) with stirring. Achieved. The serpentine was leached for 4 days before measuring the concentration of aqueous magnesium by potentiometric EDTA titration.

Results and Observation: The concentration of Mg ²⁺ was measured by an experiment by EDTA titration using a calcium ion selective electrode. Experiments on serpentine resulted in a Mg ²⁺ concentration of 0.1123 M after 4 days of leaching.

Example 4 Manufacture of precipitates from olivine Summary: A carbonate-containing precipitate was prepared using olivine as a raw material. Olivine was digested with acid. Precipitation of the precipitate involved injecting carbon dioxide and adding a proton scavenger to the metal-containing silicate material leachate (eg, olivine leachate). Characterization of the precipitate produced from the olivine leachate showed that the solid product was predominantly Neskehonite (77%), along with unidentified amorphous silicon-containing compounds. Minor components were rock salt and unidentified iron salt.

  Metallic silicate material: Olivine having an average particle size of 54.3 μm was obtained from Oliveline Corp (Bellingham, WA). The olivine fraction was reduced to an average particle size of 5.82 μm using a jet mill.

  Method: The olivine is brought to a temperature of 50 ° C. by stirring the metal-containing silicate material into 10% HCl (aqueous) (10.01 g of olivine in Jitt mill into 475.66 g of 10% HCl). We digested with. Samples were taken periodically to determine the concentration of aqueous magnesium. Stirring was maintained for 10 hours, after which the mixture was left at room temperature for an additional 9 hours. The mixture was vacuum filtered while hot, and the resulting filtrate (404.52 g) was allowed to cool to room temperature.

The filtrate was neutralized for 1 hour, after which 100% CO ₂ was vigorously sparged throughout the magnesium-containing solution. While stirring, 15.01 g NaOH (solid) was added followed by an additional 5.23 g NaOH (aq) (50% w / w) to produce a carbonate-containing precipitate. The final pH of the precipitation reaction mixture was pH 8.9. The precipitated reaction mixture slurry was vacuum filtered and the resulting filter cake was dried in an oven at 50 ° C. for 17 hours.

  The dried precipitate was characterized by XRD for crystal phase identification, SEM for morphology observation, EDS and XRF for elemental analysis, and carbon coulometric analysis for percent weight inorganic carbon measurements.

Results and observation: The concentration of Mg ²⁺ was measured in a leaching experiment by EDTA titration using a calcium ion selective electrode. An olivine leachate sample that had been subjected to a Jitt mill and leached overnight at 50 ° C. had a Mg ²⁺ concentration of 0.2491 M.

  The precipitate yielded 19.26 g of a coarse, yellow-green shade of light gray powder, suggesting the presence of iron salts. The precipitate was fairly easy to break up. SEM (Figure 8) revealed a mixture consisting primarily of thin crystalline rods and amorphous silica gel. EDS measurements showed the presence of Mg, Si, Fe, Na, and Cl.

XRD (FIG. 9) showed that the crystalline phases present in the precipitate were Neskehonite (MgCO ₃ .3H ₂ O) and rock salt (NaCl). Amorphous content was also present, suggesting that in addition to Neskehonite and rock salt, there was a phase consistent with the presence of other elements in EDS analysis.

Carbon coulometric analysis showed that the product was 4.65% (± 0.06) inorganic carbon, calculated to be 17.0% CO ₂ . Thermogravimetric analysis (TGA, FIG. 10) measured a 17.1% weight loss from 275 ° C. to 575 ° C., previously measured as the range where CO ₂ was released from Neskehonite. Given the XRD identification and the TGA and coulometric results are consistent with each other (less than 1% difference), the product was calculated to be 76.6% Neskehonite.

The precipitate also contained a silicon-based material that appeared to be a thermal decomposition product of amorphous silica (SiO ₂ ), silicic acid (H ₄ SiO ₄ ).

Example 5: Preparation of precipitate from olivine Preparation of the precipitate Summary: Olivine was digested in a solution of carbonic acid. Using KOH as the base and FeCl ₃ as the catalyst precipitated a precipitate containing digested olivine.

B. Blend Cement Production The BET specific surface area (“SSA”) of the Portland cement and precipitate used for this experiment is shown in Table 2. The particle size distribution was measured 2 minutes after the presonication to dissociate the aggregated particles. The precipitate had a much higher SSA than that of the Portland cement with which it was mixed.

  The precipitate (5% and 20% in the two different blends) was manually blended with Portland cement for approximately 2 minutes just prior to mixing the mortar. The water: cement ratio met the fluidity criteria of 110% ± 5% for the 5% substitution level (fluidity = 114%). The water: cement ratio was adjusted to 0.58 above the maximum allowable fluidity value for the 20% substitution level (fluidity = 121%).

  Change to ASTM C511 storage conditions: Cube was cured for 24 hours under wet towel covered with plastic sheet (98% estimated relative humidity).

C. Results Compressive strength growth was measured according to ASTM C109. A 2 inch side mortar cube was used for compression testing. The replacement levels of 5% and 20% precipitate were compared with normal Portland Type II / V cement mortar and with Portland Type II / V cement replaced by 20% Fly Ash F.

Example 6: Measurement of δ ¹³ C value for precipitate and starting material In this experiment, the δ ¹³ C value for precipitate and starting material is measured. A carbonate-containing precipitate was prepared using a mixture of bottled sulfur dioxide (SO ₂ ) gas and bottled carbon dioxide (CO ₂ ) gas and fly ash and silica as a surrogate source of divalent cations. The procedure was performed in a sealed container.

The starting materials were commercially available bottled SO ₂ and CO ₂ gas mixtures (SO ₂ / CO ₂ gas or “simulated flue gas”), deionized water, and fly ash.

The vessel was filled with deionized water. Fly ash was subtracted and added to deionized water to provide pH (alkaline) and a divalent cation concentration suitable for precipitation of carbonate-containing precipitates without releasing CO ₂ into the atmosphere. SO ₂ / CO ₂ gas was sparged at a rate and for a time suitable to precipitate the precipitate from the alkaline solution. Allowed enough time for interaction of the components of the reaction, after which the precipitate was separated from the remaining solution ("precipitation reaction mixture"), resulting in a wet precipitate and supernatant.

Δ ¹³ C values for the process starting material, the precipitate, and the supernatant were measured. The analytical system used was manufactured by Los Gatos Research and uses direct absorption spectroscopy to provide δ ¹³ C and concentration data for dry gases ranging from 2% to 20% CO ₂ . The instrument was calibrated using standard 5% CO ₂ gas of known isotopic composition and the measurement of CO ₂ released from samples of travertine and IAEA marble # 20 digested in 2M perchloric acid was Yielded values that were within acceptable measurement errors of the values found in the literature. The CO ₂ source gas was sampled using a syringe. CO ₂ gas is supplied to a gas dryer (Perma Pure MD Gas Dryer, Model MD-110-48F-4 made of Nafion® polymer) and then to a tabletop commercially available carbon isotope analysis system. I passed. The solid sample was first digested with heated perchloric acid (2M HClO ₄ ). CO ₂ gas was released from the closed digestion system and then entered the gas dryer. From there, the gas was collected and injected into an analytical system that yielded δ ¹³ C data. Similarly, the supernatant was digested to release CO ₂ , which was then dried and passed through an analytical instrument that provided δ ¹³ C data.

Measurements from analysis of SO ₂ / CO ₂ gas, metal silicate surrogate (ie, fly ash), carbonate-containing precipitate, and supernatant are listed in Table 4. The δ ¹³ C values for the precipitate and the supernatant are -15.88 ‰ and -11.70 ‰, respectively. The δ ¹³ C values for both products of the reaction are SO ₂ / CO ₂ gas (δ ¹³ C = -12.45 ‰) and fly ash containing some carbon that did not completely burn into the gas (δ ¹³ C = -17.46 ‰) is reflected. The product of fly ash, fossil fuel combustion itself had a δ ¹³ C that was more negative than the CO ₂ used, so the overall δ ¹³ C value of the precipitate should be more negative than that of CO ₂ itself. It reflects that. This example illustrates that the δ ¹³ C value can be used to identify the main source of carbon in carbonate-containing composites.

  Although the prior invention has been described in some detail by way of illustration and example for purposes of clarity of understanding, certain changes and modifications may be made thereto without departing from the spirit and scope of the appended claims. The good should be readily apparent to those skilled in the art in view of the teachings of the present invention. Accordingly, the preceding merely illustrates the principles of the invention. It is well understood that those skilled in the art can devise various arrangements which are not explicitly described or shown herein, but which embody the principles of the invention and are included within the spirit and scope thereof. Let's go. Further, all examples and conditional languages listed herein are primarily intended to assist the reader in understanding the principles of the present invention and the concepts that the inventor contributes to the advancement of the art. It is intended and should not be construed as limited to such specifically recited examples and conditions. Moreover, all statements herein reciting principles, aspects, and embodiments of the invention, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. Intended. In addition, such equivalents are intended to include both currently known equivalents and equivalents developed in the future, i.e., any element developed that performs the same function regardless of structure. The The scope of the invention is therefore not intended to be limited to the exemplary embodiments shown and described herein. It is intended that the following claims clarify the scope of the invention and that the methods and structures within these claims and their equivalents are covered thereby.

Claims (93)

a) digesting the metal-containing silicate material with an aqueous solution to produce a divalent cation and a material comprising SiO ₂ ;
b) reacting the divalent cation with dissolved carbon dioxide to form a precipitate;
c) drying the precipitate.   The method of claim 1, wherein the precipitate is dried to form a fine powder having a consistent particle size distribution.   The method of claim 2, further comprising the step of comminuting the metal-containing silicate material before digesting the metal-containing silicate material.   The method of claim 3, wherein the metal-containing silicate material comprises rock or mineral.   The method of claim 4, wherein the metallized silicate material comprises a mineral selected from the group consisting of orthosilicates; inosilicates; phyllosilicates; and tectosilicates.   6. The method of claim 5, wherein the orthosilicate comprises an olivine group mineral.   The method of claim 5, wherein the phyllosilicate comprises a serpentine group mineral. The material comprising metal silicates the digestion to step, comprising said digestion of a divalent cation and the acid to produce an acidic solution comprising said material containing SiO _2, Process according to claim 5. The acid is HF, HCl, HBr, HI, H ₂ SO ₄ , HNO ₃ , H ₃ PO ₄ , chromic acid, H ₂ CO ₃ , acetic acid, citric acid, formic acid, gluconic acid, lactic acid, oxalic acid, tartaric acid, 9. The method of claim 8, selected from the group consisting of ascorbic acid and meldrum acid.   The method of claim 9, wherein the acid is HCl.   9. The method of claim 8, wherein the acidic solution is contacted with a proton scavenger after digestion.   The method of claim 11, wherein the acidic solution is made into a basic solution by contact with the proton scavenger. The method of claim 12, wherein the proton scavenger comprises a hydroxide selected from the group consisting of NaOH, KOH, Ca (OH) ₂ , and Mg (OH) ₂ .   The method of claim 13, wherein the hydroxide is NaOH. A step of digesting said material comprising metal silicates is, the including digestion with proton-removing agents to produce a basic solution containing said material comprising a divalent cation and SiO _2, according to claim 5 Method.   16. The method of claim 12 or 15, wherein the divalent cation comprises an alkaline earth metal cation. The method of claim 16, wherein the alkaline earth metal cation comprises Ca ²⁺ , Mg ²⁺ , or a combination thereof.   The method of claim 17, further comprising isolating the precipitate.   The method of claim 18, wherein the precipitate is isolated from the basic solution by a liquid-solid separator.   20. A method according to claim 19, wherein the isolation of the precipitate by the liquid-solid separator is a continuous, semi-batch or batch process.   21. The method of claim 20, wherein the isolation of the precipitate is a continuous process.   The method of claim 1, wherein the precipitate is dried by a spray dryer.   The method of claim 2, wherein at least 70% of the fine powder falls within a range of ± 50 microns of a given average diameter, and the given average particle size is 50-500 microns.   24. The method of claim 23, wherein at least 70% of the fine powder falls within a range of ± 50 microns of a given average diameter and the given average particle size is 50-250 microns.   25. The method of claim 24, wherein at least 70% of the fine powder falls within a range of ± 50 microns of a given average diameter, and the given average particle size is from 100 to 200 microns.   24. The method of claim 23, wherein the precipitate comprises a pozzolanic material.   24. The method of claim 23, further comprising producing a pozzolanic material from the precipitate.   28. The method of claim 26 or 27, further comprising blending the pozzolanic material with cement. a) digesting the metal-containing silicate material with an aqueous solution to provide a material comprising a divalent cation and SiO ₂ ;
b) separating the material comprising SiO ₂ from the aqueous solution;
c) reacting the divalent cation with dissolved carbon dioxide to form a precipitate.   30. The method of claim 29, further comprising crushing the metallized silicate material prior to digesting the metallized silicate material.   32. The method of claim 30, wherein the metal-containing silicate material comprises rock or mineral.   32. The method of claim 31, wherein the metal-containing silicate material comprises a mineral selected from the group consisting of orthosilicates; inosilicates; phyllosilicates; and tectosilicates.   35. The method of claim 32, wherein the orthosilicate comprises an olivine group mineral.   33. The method of claim 32, wherein the phyllosilicate comprises a serpentine group mineral. The material comprising metal silicates the digestion to step comprises digestion with acid to produce an acidic solution containing said material comprising said divalent cation and SiO _2, The method of claim 32. The acid is HF, HCl, HBr, HI, H ₂ SO ₄ , HNO ₃ , H ₃ PO ₄ , chromic acid, H ₂ CO ₃ , acetic acid, citric acid, formic acid, gluconic acid, lactic acid, oxalic acid, tartaric acid, 36. The method of claim 35, selected from the group consisting of ascorbic acid and meldrum acid.   37. The method of claim 36, wherein the acid is HCl.   36. The method of claim 35, wherein the acidic solution is contacted with a proton scavenger after digestion.   40. The method of claim 38, wherein the acidic solution is made into a basic solution by contact with the proton scavenger. 40. The method of claim 39, wherein the proton scavenger comprises a hydroxide selected from the group consisting of NaOH, KOH, Ca (OH) ₂ , and Mg (OH) ₂ .   41. The method of claim 40, wherein the hydroxide is NaOH. The material comprising metal silicates the digestion to step, comprising said digestion of a divalent cation and proton-removing agents to produce a basic solution containing the material containing SiO _2, according to claim 32 Method.   43. The method of claim 39 or 42, wherein the divalent cation comprises an alkaline earth metal cation. ^44. The method of claim 43, wherein the alkaline earth metal cation comprises Ca ²⁺ , Mg ²⁺ , or a combination thereof. Separating said material comprising SiO ₂ from the aqueous solution, the first solution - containing separated by solid separating device, The method of claim 44.   46. The method of claim 45, wherein the separation by the first liquid-solid separation device is a continuous, semi-batch, or batch process.   48. The method of claim 46, further comprising isolating the precipitate after reacting the divalent cation with dissolved carbon dioxide.   48. The method of claim 47, wherein the precipitate is isolated from the basic solution by a second liquid-solid separator.   49. The method of claim 48, wherein the isolation of the precipitate by the second liquid-solid separation device is a continuous, semi-batch, or batch process.   50. The method of claim 49, wherein the isolation of the precipitate is a continuous process. A precipitate was separated material and a single containing the separated SiO ₂ are combined without drying to produce a pozzolanic material, The method of claim 50. Materials or isolated precipitate containing the separated SiO _2, and dried prior to combining to form a pozzolanic material, The method of claim 50. Each separated material and isolated precipitate containing SiO _2, and dried prior to combining to form a pozzolanic material, The method of claim 50. The precipitate, the material containing SiO _2, or both of the precipitate and the material containing SiO _2, and dried in a spray drier to produce a spray-dried material, according to claim 52 or 53 method .   55. The method of claim 54, wherein at least 70% of the spray-dried material falls within a range of ± 50 microns of a given average particle size, and the given average particle size is between 5 and 500 microns.   56. The method of claim 55, wherein at least 70% of the spray-dried material falls within ± 50 microns of a given average particle size, and the given average particle size is 50-250 microns.   57. The method of claim 56, wherein at least 70% of the spray dried material falls within a range of ± 50 microns of a given average particle size, and the given average particle size is between 100 and 200 microns.   56. The method of claim 55, further comprising fortifying the pozzolanic material with volcanic ash, fly ash, silica fume, highly reactive metakaolin, or ground granulated blast furnace slag.   54. A method according to any one of claims 51 to 53, further comprising blending the pozzolanic material with cement.   30. A composition produced by the method of claim 1 or 29.   A composition comprising a synthetic carbonate, a silicon-based material, and a synthetic iron-based material.   62. The composition of claim 61, wherein the synthetic carbonate comprises magnesium carbonate selected from the group consisting of alunite, magnesite, hydromagnesite, neskehonite, and lance frite.   64. The composition of claim 62, wherein the synthetic carbonate comprises nesquehonite.   64. The composition of claim 62, comprising no more than 35% silicon-based material.   65. The composition of claim 64, wherein the silicon-based material comprises silica.   66. The composition of claim 65, wherein the silica comprises amorphous silica.   66. The composition of claim 65, wherein the synthetic iron-based material comprises iron chloride or iron carbonate.   64. The composition of claim 62, wherein the synthetic carbonate further comprises calcium carbonate selected from the group consisting of calcite, aragonite, and vaterite.   62. The composition of claim 61, further comprising cement.   70. The composition of claim 69, wherein 80% or less of the composition comprises cement.   70. The composition of claim 69, wherein 55% or less of the composition comprises a silicon-based material.   62. The composition of claim 61, suitable for use in construction materials.   62. The composition of claim 61, comprising a construction material.   74. The composition of claim 72 or 73, wherein the construction material comprises cement, aggregate, cementitious material, or supplementary cementitious material. a) a processing apparatus for processing the metal-containing silicate material;
b) a precipitation reactor for precipitating the precipitate;
c) a system comprising a liquid-solid separator for separating the precipitate from the precipitation reaction mixture,
A system in which the precipitation reactor is operatively connected to both the processing unit and the liquid-solid separator.   76. The system of claim 75, wherein the processing apparatus includes a size reduction unit for comminuting the metal-containing silicate material.   77. The system of claim 76, wherein the size reduction unit comprises a ball mill or a jet mill.   77. The system of claim 76, wherein the processing apparatus further comprises a digester for digesting the metal-containing silicate material.   79. The system of claim 78, wherein the digester is configured to receive the metal-containing silicate material, and the material has a reduced size.   80. The system of claim 79, wherein the digester is further configured to receive an acid from an acid source, a proton remover from a proton remover source, or a combination thereof.   81. The system of claim 80, wherein the precipitation reactor is configured to receive a digested metal-containing silicate material.   82. The system of claim 81, wherein the precipitation reactor is further configured to receive carbon dioxide from an industrial carbon dioxide source.   83. The system of claim 82, wherein the liquid-solid separator is configured to receive a precipitation reaction mixture from the precipitation reactor.   84. The system of claim 83, wherein the liquid-solid separator is further configured to separate the precipitate from the precipitation reaction mixture.   76. The system of claim 75, further comprising a dryer for producing a dry precipitate.   The system of claim 85, wherein the dryer comprises a spray dryer.   90. The system of claim 86, wherein the spray dryer is configured to receive a slurry containing precipitate from the liquid-solid separator.   The spray dryer is arranged to produce a dry precipitate, wherein at least 70% of the dry precipitate falls within ± 50 microns of a given average particle size, and the given average particle size is 5 90. The system of claim 87, which is -500 microns.   The spray dryer is arranged to produce a dry precipitate, wherein at least 70% of the dry precipitate falls within ± 50 microns of a given average particle size, and the given average particle size is 50 90. The system of claim 88, which is -250 microns.   The spray dryer is arranged to produce a dry precipitate, wherein at least 70% of the dry precipitate falls within ± 50 microns of a given average particle size, and the given average particle size is 100 90. The system of claim 89, wherein the system is -200 microns.   90. The system of claim 87, wherein the spray dryer is further configured to utilize waste heat from an industrial carbon dioxide source.   92. The system of claim 91, wherein the industrial carbon dioxide source comprises flue gas from a coal fired power plant.   87. The system of claim 86, wherein the spray dryer is further configured to provide a heat depleted industrial carbon dioxide source to the precipitation reactor.

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