33 results about "Vaterite" patented technology

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.

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 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 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.

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 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 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%).

The application discloses a method for removing calcium and fixing carbon in fly ash washing liquid. The method uses the extraction of insoluble organic amine on acid to improve the pH value of the washing liquid system, continuously absorbs CO2, and realizes the complete removal of calcium in the fly ash washing liquid. The amine in the organic phase is regenerated by alkali, and the small amount of mixed organic diluent in the washing liquid is separated by azeotropic distillation to realize the reuse. The calcium carbonate product prepared by the method has small particles and high purity, is a high-quality globular aragonite type calcium carbonate particle, and can be used as a good adsorbent and additive material and has wide application in many fields.

The invention discloses a high-activity metakaolin-based composite mineral admixture as well as a preparation method and application thereof. The preparation method of the high-activity metakaolin-based composite mineral admixture comprises the following steps: adding a grinding aid into a kaolin-based material, and grinding to obtain kaolin-based material powder; carrying out ball-milling mixing on the kaolin-based tailing powder and an aluminum-based eutectic agent to obtain a raw material, drying the raw material, and carrying out stepped calcination to obtain a metakaolin-based material; carrying out ultrasonic dispersion mixing on the composite chemical admixture solution and the metakaolin-based material, and drying to constant weight to obtain an admixture-loaded high-activity metakaolin-based material; uniformly mixing the high-activity metakaolin-based material and the vaterite-based material to obtain a high-activity metakaolin-based composite mineral admixture; the admixture is mixed with a vaterite stabilizer to be applied to a cement-based material. The admixture disclosed by the invention has high activity, and is beneficial to improving the working performance of a cement-based material, and improving the strength and durability of the cement-based material at the same time.

Provided herein are calcium carbonate blend compositions, methods, and systems related to blend comprising vaterite particles and GCC particles.

The application discloses a method for preparing ball spar type calcium carbonate by using fly ash water washing liquid to remove hard by-products, and comprises the following steps: removing hard of the fly ash water washing liquid to obtain a filter cake; mixing the filter cake with water to prepare slurry with a mass percentage concentration of 10-30%; introducing carbon dioxide-containing gas into the slurry, controlling the pH value of the system to be 9-10.5, the molar ratio of SO4 2‑ / CO3 2‑ being 0.2-1, and performing carbonization reaction until the pH value of the system is reduced to 7.5-8.5, stopping the introduction of carbon dioxide, and aging to obtain ball spar type calcium carbonate. The method of the application uses the filter cake of the fly ash water washing liquid to remove hard by-products as raw material, uses calcium sulfate in the filter cake as a crystal type regulator, controls the pH value of the system to be 9-10.5 and the molar ratio of SO4 2‑ / CO3 2‑ being 0.2-1, and thereby induces the generation of ball spar type calcium carbonate with high purity, large specific surface area and regular morphology.

This invention provides a novel method for producing aragonite-like calcium carbonate from vaterite-like calcium carbonate, which allows for the efficient and simple production of aragonite-like calcium carbonate without the need for seed crystals of aragonite-like calcium carbonate. [Solution] The present invention provides a method for producing aragonite-like calcium carbonate, which involves preparing vaterite-like calcium carbonate by reacting a calcium ion-containing aqueous solution with a carbonate ion-containing aqueous solution at a pH of 7 to 9.7, and then immersing the prepared vaterite-like calcium carbonate in water at 65 to 95°C to produce aragonite-like calcium carbonate.

The application relates to the technical field of integrated circuit manufacturing, and discloses application of spiral calcium carbonate in grinding blocks and wafer thinning grinding wheels. The spiral calcium carbonate is applied in the grinding block, wherein the spiral calcium carbonate contains Si-O-Ca structure and is used for dispersing stress during grinding of the grinding block; 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 arranged in a spiral shape around the center, and 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; and the spiral calcium carbonate is induced by calcium ions and amino silane aspartic acid. Through the technical scheme, the problem of poor flatness of a wafer after thinning in the related art is solved.

The application relates to the technical field of vaterite, and particularly relates to a method for preparing high-purity vaterite based on solid waste carbonization reaction, which comprises the following steps: A, detecting the content of calcium oxide in steel slag to obtain a detection result; B, the mass ratio of the steel slag, magnesium slag and calcium oxide powder in the composite calcium source is determined according to the detection result; C, a pretreated calcium source is obtained; D, the pretreated calcium source is treated to obtain a leaching solution; E, the leaching solution is treated to obtain a reaction filtrate; F, polyethylene glycol is added into the reaction filtrate to obtain a reaction dispersion liquid; carbonization reaction is carried out by introducing a gas containing carbon dioxide into the reaction dispersion liquid, and then high-purity vaterite is obtained after the reaction dispersion liquid is subjected to filtration, centrifugal separation, washing and drying in sequence. The method for preparing high-purity vaterite based on solid waste carbonization reaction is beneficial to improving the purity, particle size uniformity and yield of vaterite on the premise of enriching the types of calcium sources, so as to overcome the defects in the prior art.

This invention relates to the field of solid waste resource utilization and carbon dioxide mineralization, and discloses a method for preparing high-purity aragonite based on an alkanolamine-phosphogypsum synergistic system. The method includes the following steps: pulverizing and drying phosphogypsum, reacting it fully with a multidentate chelating alkanolamine solution, and then separating the solid and liquid phases to obtain purified phosphogypsum; mixing the purified phosphogypsum with a monoethanolamine solution, introducing a mixed gas containing CO2, and carrying out a mineralization reaction under stirring; after the reaction, separating the solid and liquid phases to obtain aragonite solid and liquid phases; washing and drying the aragonite solid to obtain aragonite; this invention uses a multidentate chelating alkanolamine as a phosphogypsum impurity remover, achieving "fluorine dissolution and calcium retention," with a fluorine removal rate ≥90% and a calcium sulfate loss rate ≤5%; during the mineralization process, monoethanolamine is used to inhibit the conversion of aragonite to calcite to obtain high-purity aragonite, and the obtained aragonite has a spherical morphology and uniform particle size distribution. This invention has no high-temperature calcination or acidic waste liquid throughout the entire process, and has significant advantages such as low energy consumption, high stability, and synergistic resource utilization.

The invention relates to the technical field of building materials, and discloses graphene-nano calcium carbonate / nano silicon dioxide based cement which comprises the following components in parts by weight: 60-90 parts of Portland cement; 0.05 to 1 part of nano silicon dioxide; the graphene-nano calcium carbonate composite material accounts for 0.02%-0.04% of the total mass of the Portland cement and the nano silicon dioxide; the graphene-nano calcium carbonate composite material is prepared by mixing graphene nanosheets, a calcium chloride solution and a sodium carbonate solution, and the invention further provides a preparation method of the graphene-nano calcium carbonate / nano silicon dioxide based cement. The preparation method comprises the following steps: S1, preparing graphene nanosheets; s2, pre-adsorbing calcium ions; s3, in-situ synthesis of vaterite-phase calcium carbonate; s4, separation and purification; and S5, mixing. The vaterite-phase nano calcium carbonate is synthesized on the surface of the graphene in situ to form an efficient reinforced structure, so that the problem that the strength reinforcing effect of a cement material is limited is solved.

The invention discloses a mineralized modified biochar admixture and a preparation method thereof. The method comprises the following steps: firstly, preparing modified biochar through a controllable airflow mineralization technology: leaching carbide slag with an ammonium chloride solution to obtain Ca < 2 + > filtrate, then adding biochar, introducing CO2 under specific conditions to carry out mineralization reaction, and generating vaterite type calcium carbonate loaded modified biochar; preferably, the reaction temperature is 30 DEG C, the CO2 flow rate is 80 mL / min, the reaction time is 30 min, and the solid-to-liquid ratio is 500 g / L. The mineralized modified biochar admixture is applied to replace cement in a cement-based material, and the preferable mass replacement ratio is 5%-30%, and further preferable mass replacement ratio is 10%-20%. According to the present invention, the industrial solid waste carbide slag and the CO2 gas are adopted as the modification raw materials to mineralize the biochar derived from the forestry and agricultural residues, and the prepared mineralized modified biochar admixture realizes the fixation of CO2, and can be used for the building material with characteristics of good mechanical property and significant negative carbon effect.