46 results about "Vaterite" patented technology

The invention provides a method for preparing vaterite type nanoscale calcium carbonate with ardealite as a raw material and application of the method, and relates to the technical field of inorganic nano-material preparation.The method comprises the following steps that firstly, efficient dissociation of calcium ions in the ardealite is achieved through a phase transfer method, then digestion treatment is conducted on a leaching solution, and the leaching solution is obtained; a crystal morphology regulating agent is further introduced to construct a mineralized microenvironment, and then through a carbon dioxide carbonization reaction, vaterite type nano-scale calcium carbonate with a specific average particle size (200-400 nm) is prepared. According to the preparation method, natural high polymer materials such as collagen are introduced in the preparation process to serve as green crystal form guiding agents, so that the coordination effect of the natural high polymer materials and calcium ions can be utilized, the crystal morphology can be effectively regulated and controlled, and the biocompatibility of the nano material is improved; and the application possibility of calcium carbonate in the biomedical fields of drug carriers, bone repair materials and the like is expanded.

The invention discloses a coated defluorination composite material based on a microbial mineralization technology and a preparation method thereof. According to the coated defluorination composite material, urease vaterite calcium carbonate particles are used as a material core part, and the outer surface of the core part is coated with a calcium cross-linked porous composite film to serve as a coating layer of the material; the calcium cross-linked porous composite membrane is a porous membrane material formed by cross-linking calcium ions and a porous matrix, and the porous matrix is selected from any one of chitosan, cellulose, sodium alginate and porous silicon; the urease vaterite calcium carbonate particles are generated in situ after urea hydrolysis is catalyzed by urease and a calcium source is added. The composite material has the advantages of efficient defluorination effect and good stability when used in fluorine-containing wastewater, and the preparation method of the coated defluorination composite material is simple and easy to implement.

The purpose of the present invention is to provide a concrete that has sufficient strength while reducing the amount of CO2 emission. The present invention pertains to an agent for accelerating production of calcium carbonate having a vaterite-type crystal structure. The accelerating agent contains a compound having a plurality of amino groups, and is used when reacting carbon dioxide with a composition containing 5 mass% or more of calcium silicate hydrate.

The invention belongs to the technical field of calcium carbonate synthesis, and particularly relates to a preparation method and application of vaterite type calcium carbonate. The preparation method of vaterite type calcium carbonate comprises the following steps: (1) mixing a calcium-containing raw material, an ammonia source and a surfactant, and reacting to obtain a calcium ion leachate; (2) introducing gas containing carbon dioxide into the calcium ion leachate, reacting and separating to obtain vaterite type calcium carbonate and filtrate; in the step (1), the pH value of the mixed system is 8-12; in the step (2), the pH value of the reaction is 8-12. The pH value of the reaction system is controlled to be 8-12, so that the reaction system can form an NH3 / NH4 < + > system, the vaterite crystal surface energy is adsorbed and reduced, conversion to calcite is inhibited, and the purity and low-temperature stability of vaterite type calcium carbonate are improved. In addition, the filtrate obtained by the method can be used as an ammonia source to return to the step (1) for recycling.

The present application belongs to the technical field of paper deacidification, and particularly relates to a method for deacidifying and reinforcing paper by using nanocellulose and vaterite calcium carbonate. The method uses vaterite calcium carbonate as a deacidifying agent and γ-aminopropyl triethoxysilane modified nanocellulose as a reinforcing agent to achieve deacidification and reinforcement of paper. The concentration of the vaterite calcium carbonate dispersion is 5-20 g / L, the concentration of the modified nanocellulose dispersion is 0.5-5 g / L, and the dispersing agents for both are ethanol. The method has good deacidification, reinforcement and anti-aging effects on paper.

Various aspects present advantageous composition with substituting SCMs in blended cements with vaterite at levels between 5% and 15%. In the cement-fly ash blends, the replacement of 10% of fly ash with vaterite resulted in a 40% increase in strength after 1 day, and the increased compressive strength persisted over a 56-day period when compared to the control cement-fly ash blend. Aspect systems may comprise a first reactor, operating at a first temperature, and configured to calcine limestone and produce Portland cement and a gaseous composition comprising carbon dioxide, a second reactor, operating at a second temperature which is lower than the first temperature, and configured to produce vaterite using a portion of the carbon dioxide, and a blending reactor configured to produce a cementitious blend comprising the Portland cement, the vaterite, and SCM.

Various aspects present advantageous composition with substituting SCMs in blended cements with vaterite at levels between 5% and 15%. In the cement-fly ash blends, the replacement of 10% of fly ash with vaterite resulted in a 40% increase in strength after 1 day, and the increased compressive strength persisted over a 56-day period when compared to the control cement-fly ash blend. Aspect systems may comprise a first reactor, operating at a first temperature, and configured to calcine limestone and produce Portland cement and a gaseous composition comprising carbon dioxide, a second reactor, operating at a second temperature which is lower than the first temperature, and configured to produce vaterite using a portion of the carbon dioxide, and a blending reactor configured to produce a cementitious blend comprising the Portland cement, the vaterite, and SCM.

The invention discloses a preparation method of a calcium carbonate-polyvinyl alcohol composite aerogel material, and belongs to the technical field of thermal insulation materials. The invention aims to solve the problems that the crystallization behavior of calcium carbonate is difficult to effectively regulate and control and the porous structure and the heat insulation function of aerogel are easily damaged in the prior art. The method comprises the following steps: reacting a mixed solution of calcium chloride and magnesium chloride with carbon dioxide to prepare micro-nano amorphous calcium carbonate and a small amount of nano calcite; co-doping the chitosan and aspartic acid into polyvinyl alcohol hydrogel, uniformly mixing, and carrying out directional freezing and freeze-drying treatment; finally, high-concentration carbon dioxide atmosphere treatment is adopted in a humid and hot environment, amorphous calcium carbonate is induced to be dissolved on the polyvinyl alcohol framework and recrystallized into calcite and vaterite shell layers, and therefore the composite aerogel material is obtained. While good heat insulation performance and flexibility are maintained, the mechanical strength and damp and heat resistance stability of the material are remarkably improved, efficient curing and utilization of carbon dioxide are achieved, and the material is suitable for the field of green energy-saving buildings.

The present invention provides compositions, methods, and systems for forming vaterite and magnesium oxide. [Solution] This specification provides compositions, methods, and systems comprising vaterite and magnesium oxide. In some embodiments of the above-described aspects, the method further comprises the step of generating a solid comprising magnesium oxide in step (ii), and treating an aqueous solution comprising a calcium salt and magnesium oxide, as well as the solid comprising magnesium oxide, with a gas stream comprising carbon dioxide to form a composition comprising vaterite, magnesium oxide, and a solid comprising magnesium oxide.

Methods are provided herein comprising: a) calcining limestone in a cement plant to form carbon dioxide and a calcium compound selected from calcium oxide, calcium hydroxide, or combinations thereof; b) treating the calcium compound with N-containing salt in water to produce an aqueous solution comprising calcium salt and N-containing salt; and c) contacting the aqueous solution with carbon dioxide under one or more precipitation conditions to produce a precipitate comprising calcium carbonate and a supernatant aqueous solution wherein the calcium carbonate comprises vaterite.

Various aspects relate to production of synthetic aragonite material. In some aspects direct precipitation of aragonite, via controlling certain environmental conditions, is disclosed. In some aspects aragonite crystals may grow on seeds of other particles, such as aragonite crystals, to produce long aragonite structures. In some aspect, metastable calcium carbonate such as vaterite or amorphous calcium carbonate is transformed into aragonite. In various aspects different compositions of calcium carbonate polymorphs, including aragonite, with different aspect ratios are used to produce cementitious or non-cementitious compositions with superior properties.

A carbon dioxide mineralization process is disclosed, which includes introducing ammonium hydroxide solution and a calcium chloride solution into a reaction vessel to form a mixed solution, introducing carbon dioxide gas into the reaction vessel, and forming a calcium carbonate precipitate. Implementations of the carbon dioxide mineralization process can include where the mixed solution further may include tannic acid. A concentration of tannic acid can be from about 0 mg / mL to about 2 mg / mL. A flow rate of the introduction of carbon dioxide gas can be from about 0 L / min to about 1.0 L / min. The carbon dioxide mineralization process may include providing ultrasonic energy at a frequency of from about 20 khz to about 130 khz to the mixed solution. The carbon dioxide mineralization process may include filtering the calcium carbonate precipitate through a polyvinylidene fluoride membrane. The calcium carbonate precipitate may include a metastable vaterite phase.

The invention relates to a method for regulating and controlling the crystal form of calcium carbonate by using electromagnetic pulses, which comprises the following steps: emitting electromagnetic pulses with corresponding frequencies to a mixed solution of a calcium ion source solution and a carbonate ion source solution to regulate and control the forming process of calcium carbonate crystals, thereby regulating the crystal form of the generated calcium carbonate crystals. Compared with a traditional method for directionally synthesizing the calcium carbonate crystal form, the method does not need to regulate and control synthesis conditions and raw material ratio, use a control agent and a guiding agent and other operations, effectively avoids the problems of harsh synthesis conditions, complex steps, poor stability and the like in traditional synthesis, can reduce the reaction time and intermediate loss, improves the production efficiency, and is suitable for industrial production. Finally, calcite type, aragonite type or vaterite type calcium carbonate crystals which have different physicochemical properties and are suitable for different application scenes can be stably and efficiently obtained.

The present application relates to the technical field of calcium carbonate manufacturing, and particularly relates to a preparation method of high-whiteness light calcium carbonate. The method comprises the following steps: efficient leaching of calcium element in carbide slag; preparation of microbial crystal form control agent; and electric dispersion treatment and precipitation of calcium ions. The microbial crystal form control agent is prepared by adjusting the mixing ratio of Bacillus pumilus fermentation liquor and Pseudomonas fluorescens fermentation liquor, so that Ca 2+ The stearic acid and sodium polyacrylate in the microbial crystal form control agent can make the particles more stable and provide ion adsorption capacity after the larger calcium carbonate particles are mineralized, CO2 is introduced after temperature rising, and the crystal form of the calcium carbonate is optimized, so that the vaterite type crystallization with smaller crystal form is formed. The Bacillus pumilus can also assist in generating small-particle-size calcium carbonate over time, so that the high-whiteness small-particle-size light calcium carbonate is obtained.

Various aspects relate to production of synthetic aragonite material. In some aspects direct precipitation of aragonite, via controlling certain environmental conditions, is disclosed. In some aspects aragonite crystals may grow on seeds of other particles, such as aragonite itself, to produce long aragonite structures. In some aspect, metastable calcium carbonate such as vaterite or amorphous calcium carbonate is transformed into aragonite. In various aspects different compositions of calcium carbonate polymorphs, including aragonite, with different aspect ratios are used to produce cementitious or non-cementitious compositions with superior properties.

The invention belongs to the technical field of auxiliary cementing material preparation, and particularly relates to a method for preparing a high-activity auxiliary cementing material from recycled concrete fine powder. The preparation method comprises the following steps: infiltrating RCF by using ammonia water, then carrying out wind power suspension carbonation treatment to obtain a high-activity auxiliary cementing material, carrying out wind power suspension carbonation (WSC) treatment, reassembling a particle structure of the RCF to form RCF wrapped by calcium carbonate capsules, and inducing vaterite type calcium carbonate to be formed on the surface of the RCF by using an NH3.H2O solution as a crystal form control agent, so that the RCF is subjected to high-activity and high-activity auxiliary cementing material. The vaterite'capsule 'formed by the method not only reduces the water absorption of the RCF, but also improves the reaction activity.

The invention discloses a stable preparation method of an unsteady vaterite calcium carbonate crystal, and belongs to the technical field of inorganic material preparation. According to the method, gamma-dicalcium silicate (gamma-C2S) is taken as a slow-release calcium source, amino acid is taken as a crystal form regulating agent, CO2 is introduced into a system at normal temperature and normal pressure for a carbonization reaction, and an unstable state reaction environment of instantaneous supersaturation-dynamic passivation-heterogeneous adsorption is constructed, so that controllable nucleation of vaterite is realized, and transformation of vaterite to calcite is remarkably inhibited. Optionally, gypsum powder can be added as a crystal form stabilizer, and the stability of vaterite is further enhanced through heterogeneous adsorption. The process is simple, green and energy-saving, and the obtained vaterite calcium carbonate crystal is high in purity, regular in morphology and excellent in long-term stability in water, and is suitable for the fields of carbon mineralization carbon sequestration, functional fillers, low-carbon building materials and the like.

The application discloses an Escherichia coli coated calcium carbonate composite material powder, a block and a preparation method thereof. The preparation method comprises the following steps: mixing and stirring natural Escherichia coli expressing GFP and a buffer solution containing calcium ions to obtain a suspension; adding an aqueous solution containing carbonate ions into the suspension, and after the adding is completed, centrifuging, washing and drying to obtain the Escherichia coli coated calcium carbonate composite material powder. The application effectively combines the natural Escherichia coli expressing GFP and calcium ions to inhibit the crystal type conversion, and after the titration is completed, the centrifugation and washing are rapidly performed, so that the single vaterite powder with stable crystal type is successfully prepared, and then the composite material block is prepared through a cold sintering process. The operation method is simple, the cost is low, and the application is suitable for large-scale production, so that a new research idea is provided for preparing a large-size heterogeneous composite material which can realize the synergistic improvement of strength and toughness and has a macroscopic geometric shape.

The invention belongs to the technical field of nano calcium carbonate processing, and discloses aging equipment for processing nano calcium carbonate, which comprises an aging tank body, and further comprises an initial aging assembly which is arranged on the aging tank body and is used for playing an initial mild circulation effect in the initial aging of nano calcium carbonate and maintaining the integrity of crystals. By means of multi-stage composite stirring, the defect that existing aging equipment is poor in adaptability is overcome in a targeted mode, precise adaptation of all aging stages of nano calcium carbonate slurry with different viscosities is achieved, metastable-state crystal vaterite / aragonite can be prevented from being broken through mild circulation of a hollow pipe and a spiral blade at the early stage of aging, and the integrity of crystals is maintained; in the middle stage, the rotation of the inclined cutter and the slurry dispersing height can be adjusted by means of the electric cylinder, the shearing dispersion of the high-viscosity slurry is enhanced, a foundation is laid for hard agglomeration breaking, and in the later stage, the large-range low-shearing paddles are used for protecting the shaped calcite crystals, ensuring the ageing sufficiency and providing a stable material environment for subsequent quality optimization.

Various aspects present advantageous composition with substituting SCMs in blended cements with vaterite at levels between 5% and 15%. In the cement-fly ash blends, the replacement of 10% of fly ash with vaterite resulted in a 40% increase in strength after 1 day, and the increased compressive strength persisted over a 56-day period when compared to the control cement-fly ash blend. Aspect systems may comprise a first reactor, operating at a first temperature, and configured to calcine limestone and produce Portland cement and a gaseous composition comprising carbon dioxide, a second reactor, operating at a second temperature which is lower than the first temperature, and configured to produce vaterite using a portion of the carbon dioxide, and a blending reactor configured to produce a cementitious blend comprising the Portland cement, the vaterite, and SCM.

Provided herein are methods and systems to form calcium carbonate comprising vaterite, comprising dissolving limestone in an aqueous base solution under one or more precipitation conditions to produce a precipitation material comprising calcium carbonate and a supernatant solution, wherein the calcium carbonate comprises vaterite.

The application provides a method for preparing a ball spar type CaCO3 by sodium malonate directional regulation of phosphogypsum CO2 mineralization, which is based on an ammonia-induced phosphogypsum direct CO2 mineralization system, and the phosphogypsum is washed to obtain phosphogypsum particles; the washed phosphogypsum, ammonia water and deionized water are prepared into a suspension, CO2 gas is continuously introduced into a reactor, and after stirring reaction, solid-liquid separation is performed to obtain ball spar type CaCO3 solid particles and an ammonium sulfate-rich solution; the method uses sodium malonate as a crystal form regulator of the product CaCO3, and ball spar type CaCO3 is prepared in a one-step direct mineralization process; the crystal form regulator sodium malonate is green and environmentally friendly, can effectively directional regulate the crystal form of the mineralization product CaCO3, and solves the problems of large amount of crystal form regulator and complex process in the existing process for preparing ball spar type CaCO3 by phosphogypsum CO2 mineralization; the process is simple, the cost is low, and the method is suitable for large-scale industrial production of the ball spar type CaCO3.

Provided herein are compositions, methods, and systems related to bimodal, trimodal, and / or multi-modal distribution of reactive vaterite cement particles.

The present invention relates to a composition or material, in particular a catalytically active composition or material, comprising - permanently polarized hydroxyapatite and - vaterite and / or vaterite-like material. Further, the present invention relates to a method for producing said composition or material, a composition or material obtained or obtainable by said method and the use of said composition or material.

The invention relates to the technical field of special cement, and particularly discloses a multifunctional oil well cement formula and a preparation process thereof, and the multifunctional oil well cement formula is prepared from the following components by weight: 100 parts of G-grade high sulfate resistance oil well cement; 20 to 60 parts of gradient modified expanded perlite; 0.8 to 1.2 parts of basalt fiber; 2-4 parts of a bio-based mineralizer; 0.3 to 0.8 part of a polycarboxylic acid dispersant; and 45 to 55 parts of water. According to the CO2 activation process in the scheme, high-purity CO2 gas is injected through pulses, amorphous CaCO3 and vaterite crystals (50-200 nm) are generated on the nanoscale, and cement pores are filled with the products to form a compact structure. Firstly, the nanoscale size of amorphous CaCO3 can effectively bridge cement matrix microcracks, and the compressive strength is improved (expected to be improved by 15%-20%); and secondly, the generation of vaterite optimizes an interface transition region, reduces the permeability, reduces the diffusion coefficient of chloride ions by more than 30%, and significantly enhances the sulfate attack resistance.

The invention relates to a vaterite carrier, a dye-loaded vaterite functional filler, a preparation method of the dye-loaded vaterite functional filler and an anti-corrosion early-warning coating. The preparation method of the vaterite carrier comprises the following steps: placing a calcium salt aqueous solution in a reactor with a sand core gas disperser, introducing high-purity CO2 gas into the reaction system through the sand core gas disperser, continuously introducing CO2, monitoring the pH value of the reaction liquid, stopping the reaction, immediately stopping introducing gas, filtering, washing, and drying to obtain the vaterite carrier. And dispersing the washed wet filter cake to form a suspension with the solid content of 10%-20%, and performing spray drying to form the vaterite carrier with a porous or hollow structure. According to the coating provided by the invention, when the local humidity of the coating is increased and moisture permeates, vaterite is subjected to phase change, and extrusion force generated by structural densification pumps dye in pores out to the surface of the coating, so that macroscopic color change (such as blue or red spots) is generated, and visual early warning without external energy is realized.

This invention discloses a stable preparation method for unsteady aragonite calcium carbonate crystals, belonging to the field of inorganic material preparation technology. The method uses γ-type dicalcium silicate (γ-C2S) as a slow-release calcium source and amino acids as crystal form regulators. CO2 is introduced into the system at room temperature and pressure to initiate a carbonization reaction. By constructing an unsteady reaction environment of "instantaneous supersaturation-kinetic passivation-heterogeneous adsorption," controllable nucleation of aragonite is achieved, and its transformation to calcite is significantly inhibited. Optionally, gypsum powder can be added as a crystal form stabilizer to further enhance the stability of aragonite through heterogeneous adsorption. This invention features a simple, green, and energy-saving process, yielding aragonite calcium carbonate crystals with high purity, regular morphology, and excellent long-term stability in water. It is suitable for applications such as carbon mineralization and carbon fixation, functional fillers, and low-carbon building materials.

The invention relates to the technical field of integrated circuit manufacturing, and provides a grinding wheel for wafer thinning, a preparation method of the grinding wheel, wafer thinning equipment and a wafer thinning method. The grinding wheel for wafer thinning comprises a base material and a plurality of grinding blocks, and each grinding block comprises spiral calcium carbonate containing a Si-O-Ca structure and is used for dispersing stress during grinding; the crystal form of the spiral calcium carbonate is vaterite type, the spiral calcium carbonate comprises a plurality of flaky crystals, the plurality of flaky crystals are spirally arranged around the center, and the adjacent flaky crystals are partially stacked, so that the spiral calcium carbonate has a chiral characteristic, and the plurality of flaky crystals can disperse stress during grinding; the spiral calcium carbonate containing the Si-O-Ca structure is formed by inducing calcium ions through amino silanization aspartic acid. According to the technical scheme, the problem that the flatness of the thinned wafer is poor in the prior art is solved.

The invention discloses a method and a system for recycling bypass exhaust flue gas of a cement kiln. The recycling method for the bypass exhaust flue gas of the cement kiln comprises the following steps: cooling, dedusting and washing the bypass exhaust flue gas of the cement kiln to obtain a water-washing salt-extracting solution and washed flue gas; mixing the washing salt extraction liquid with the washing flue gas to react to generate a carbonized liquid, carrying out solid-liquid separation on the carbonized liquid, and removing carbon dioxide from a liquid phase part to obtain a calcium-containing liquid; taking part of the calcium-containing liquid to react with ammonia water to generate crystal nucleus turbid liquid, adding the crystal nucleus turbid liquid into the residual calcium-containing liquid, and adding the ammonia water for reaction in batches to obtain vaterite turbid liquid; and carrying out solid-liquid separation on the vaterite suspension, and drying the obtained slag phase to obtain a vaterite product. According to the invention, a'dissolution-recrystallization 'coupling process is provided for the first time, and efficient and controllable synthesis of vaterite in the waste liquid with ultralow calcium concentration is realized. The method not only realizes collaborative resourceful treatment of industrial wastes, but also promotes high-valued conversion and cyclic utilization of the low-calcium waste liquid.

The application provides a low-carbon cementing material based on metakaolin solid waste and vaterite and a preparation method thereof; the material is composed of solid raw materials in the following mass fractions: 50-55 parts of cement, 22-33 parts of metakaolin solid waste, 14-18 parts of vaterite and 1-2 parts of gypsum; wherein the metakaolin solid waste includes low-activity calcined coal gangue and calcined kaolin tailings, and the kaolin content in the raw material before calcination of the metakaolin solid waste is 15%-25%; the preparation method of the material includes calcination of the metakaolin solid waste, preparation of vaterite and preparation of neat paste according to the proportion. By introducing vaterite as a reaction accelerator, the application cooperates to stimulate the potential pozzolanic effect of low-activity calcined coal gangue, breaks through the activity limitation of the rich aluminum phase, and realizes efficient resource utilization of low-grade metakaolin solid waste (kaolin content 15%-25%).