Provided is a method for producing a calcium carbonate sintered body whereby a good sintered body can be obtained without having to use any sintering aid. A method for producing a calcium carbonate sintered body includes the steps of: compacting calcium carbonate to make a green body; heating the green body under a condition of a temperature of 500° C. or lower to remove an organic component contained in the green body; and sintering the green body under conditions of a carbon dioxide atmosphere and a temperature of 450° C. or higher to obtain a calcium carbonate sintered body.

Mesomorphic ceramic films are fabricated over large areas by blade-coating of nematic lyotropic suspensions, followed by calcination. Lyotropic self-assembly of titania or ZnO nanorods by applying blade-coating shear force to a dispersion of the rods, followed by thermal treatment forms transparent ceramic films for applications such as large aperture inorganic waveplates for modifying the polarization state of incident light that have superior optical and mechanical properties

Provided herein are integrated biomass combustion-carbonation gas conditioning systems to directly sequester carbon dioxide from biomass-derived CO.sub.2-containing flue gas. The CO.sub.2 is sequestered by mineral carbonation in concrete materials within a carbonation reactor. The mineral carbonation processes sequester CO.sub.2 in concrete materials, aqueous slurries, or aggregates without any additional carbon enrichment process. Contacting a CO.sub.2-containing gas stream from a biomass combustion apparatus with concrete, aggregate, or alkaline solutions, causes a carbonation reaction in which carbonation products such as calcium carbonate (CaCO.sub.3) and alumina silica gel are formed. The carbonation reactions set forth herein are useful for strengthening concrete and concrete components. Certain processes herein condition the biomass-derived flue gas. The conditioning includes condensing the gas to remove acidic gas, and to remove particulates and water. The conditioning includes adjusting the temperature, relative humidity, and gas flow rate of the biomass-derived flue gas without any carbon capture step before entering the carbonation reactor. The permanent storage of CO.sub.2 in concrete materials reduces carbon emissions from biomass combustion systems. The process does so, in certain embodiments, at low temperatures, ambient pressure, and even under dilute CO.sub.2 concentrations in CO.sub.2-containing flue gas streams. For example, the CO.sub.2 concentration in a CO.sub.2-containing flue gas stream from a biomass combustion system may be lower than 20 volume percent (vol %) and be used to produce low-carbon concrete materials.

A method of producing a product inorganic compound including: immersing a raw material inorganic compound having a volume of 10.sup.−13 m.sup.3 or more in an electrolyte aqueous solution or an electrolyte suspension; exchanging anions in the raw material inorganic compound with anions in the electrolyte aqueous solution or the electrolyte suspension; cations in the raw material inorganic compound are exchanged with cations in the electrolyte aqueous solution or the electrolyte suspension; or including a component (that excludes water, hydrogen, and oxygen) in the electrolyte aqueous solution or the electrolyte suspension not included in the raw material inorganic compound in the raw material inorganic compound; and obtaining a product inorganic compound having a volume of 10.sup.−13 m.sup.3 or more from the raw material inorganic compound.

A method of producing a product inorganic compound including: immersing a raw material inorganic compound having a volume of 10.sup.−13 m.sup.3 or more in an electrolyte aqueous solution or an electrolyte suspension; exchanging anions in the raw material inorganic compound with anions in the electrolyte aqueous solution or the electrolyte suspension; cations in the raw material inorganic compound are exchanged with cations in the electrolyte aqueous solution or the electrolyte suspension; or including a component (that excludes water, hydrogen, and oxygen) in the electrolyte aqueous solution or the electrolyte suspension not included in the raw material inorganic compound in the raw material inorganic compound; and obtaining a product inorganic compound having a volume of 10.sup.−13 m.sup.3 or more from the raw material inorganic compound.

Provided is a calcium carbonate that comprises crystals having a particular shape and structure and has a nano-order average particle size. Provided are a method for producing a calcium carbonate that comprises crystals having a particular shape and structure and has an average particle size in a particular range and a crystal growth method. The calcium carbonate has the calcite structure, has a BET specific surface area of 2 to 50 m.sup.2/g, has a number-based average particle size of 30 nm to 1.0 μm as determined by electron microscopy, and partially comprises substantially ring-like particles.

The present invention concerns a process for the preparation of flocculated filler particles, wherein at least two aqueous suspensions of at least one filler material and at least one flocculating additive are combined.

The disclosure herein sets forth processes and compositions for producing carbonated materials comprising calcium carbonates through a mechanochemical process. The present disclosure concerns the production of calcium carbonate by sequestrating CO.sub.2. Certain processes herein include providing alkaline-rich mineral materials that include carbonatable solid wastes such as lime kiln dust, cement kiln dust, and coal combustion residues, and simultaneously fractioning the alkaline-rich mineral materials, while contacting the alkaline-rich mineral materials with a CO.sub.2-containing gas in carbonation reactor at low temperature and ambient pressure. In some embodiments, the alkaline-rich mineral materials are partially carbonated before being used in the processes disclosed herein. After contacting the alkaline-rich mineral materials with a CO.sub.2-containing gas in carbonation reactor at low temperature and ambient pressure, solid calcium carbonate is produced. In aqueous reactors, the solid calcium carbonate is filtered from a solution in which it precipitated, and the remaining solution includes hydroxide as well as alkaline metal ions. The solution filtered from the solid calcium carbonate can be sequentially contacted with a CO.sub.2-containing gas stream to precipitate additional calcium carbonate. The carbonated materials formed from these processes can be used in the form of a slurry, as a moist powder, as a dried powder, as a reactive filler or as a supplementary cementitious material in a mixture that is used to make concrete.

The disclosure herein sets forth processes and compositions for producing carbonated materials comprising calcium carbonates through a mechanochemical process. The present disclosure concerns the production of calcium carbonate by sequestrating CO.sub.2. Certain processes herein include providing alkaline-rich mineral materials that include carbonatable solid wastes such as lime kiln dust, cement kiln dust, and coal combustion residues, and simultaneously fractioning the alkaline-rich mineral materials, while contacting the alkaline-rich mineral materials with a CO.sub.2-containing gas in carbonation reactor at low temperature and ambient pressure. In some embodiments, the alkaline-rich mineral materials are partially carbonated before being used in the processes disclosed herein. After contacting the alkaline-rich mineral materials with a CO.sub.2-containing gas in carbonation reactor at low temperature and ambient pressure, solid calcium carbonate is produced. In aqueous reactors, the solid calcium carbonate is filtered from a solution in which it precipitated, and the remaining solution includes hydroxide as well as alkaline metal ions. The solution filtered from the solid calcium carbonate can be sequentially contacted with a CO.sub.2-containing gas stream to precipitate additional calcium carbonate. The carbonated materials formed from these processes can be used in the form of a slurry, as a moist powder, as a dried powder, as a reactive filler or as a supplementary cementitious material in a mixture that is used to make concrete.

The invention relates to a method for producing an implant which contains a composite powder comprising microstructured particles, obtainable by a method in which large polymer particles are bonded to small spherical calcium carbonate particles. Said calcium carbonate particles can be obtained by a method with the following steps: a) providing a calcium hydroxide suspension, b) introducing carbon dioxide or a carbon dioxide-containing gas mixture into the suspension from step a), and c) separating the calcium carbonate particles formed, while adding 0.3 wt.-% to 0.7 wt.-% of at least one amino trialkylene phosphonic acid.