1394results about "Calcium/strontium/barium carbonates" patented technology

A method and apparatus to extract and sequester carbon dioxide (CO₂) from a stream or volume of gas wherein said method and apparatus hydrates CO₂, and reacts the resulting carbonic acid with carbonate. Suitable carbonates include, but are not limited to, carbonates of alkali metals and alkaline earth metals, preferably carbonates of calcium and magnesium. Waste products are metal cations and bicarbonate in solution or dehydrated metal salts, which when disposed of in a large body of water provide an effective way of sequestering CO₂ from a gaseous environment.

A process for selectively removing carbon dioxide from a gaseous stream by converting the carbon dioxide to a solid, stable form is provided. In a sequestration process, carbon dioxide enriched air is passed through a gas diffusion membrane to transfer the carbon dioxide to a fluid medium. The carbon dioxide rich fluid is then passed through a matrix containing a catalyst specific for carbon dioxide, which accelerates the conversion of the carbon dioxide to carbonic acid. In the final step, a mineral ion is added to the reaction so that a precipitate of carbonate salt is formed. This solid mineral precipitate can be safely stored for extended periods of time, such as by burying the precipitate in the ground or depositing the precipitate into storage sites either on land or into a body of water. An apparatus for removing carbon dioxide from a gaseous stream is also provided.

Hydrogen is produced from solid or liquid carbon-containing fuels in a two-step process. The fuel is gasified with hydrogen in a hydrogenation reaction to produce a methane-rich gaseous reaction product, which is then reacted with water and calcium oxide in a hydrogen production and carbonation reaction to produce hydrogen and calcium carbonate. The calcium carbonate may be continuously removed from the hydrogen production and carbonation reaction zone and calcined to regenerate calcium oxide, which may be reintroduced into the hydrogen production and carbonation reaction zone. Hydrogen produced in the hydrogen production and carbonation reaction is more than sufficient both to provide the energy necessary for the calcination reaction and also to sustain the hydrogenation of the coal in the gasification reaction. The excess hydrogen is available for energy production or other purposes. Substantially all of the carbon introduced as fuel ultimately emerges from the invention process in a stream of substantially pure carbon dioxide. The water necessary for the hydrogen production and carbonation reaction may be introduced into both the gasification and hydrogen production and carbonation reactions, and allocated so as transfer the exothermic heat of reaction of the gasification reaction to the endothermic hydrogen production and carbonation reaction.

Apparatuses and methods for removing carbon dioxide and other pollutants from a gas stream are provided. The methods include obtaining hydroxide in an aqueous mixture, and mixing the hydroxide with the gas stream to produce carbonate and/or bicarbonate. Some of the apparatuses of the present invention comprise an electrolysis chamber for providing hydroxide and mixing equipment for mixing the hydroxide with a gas stream including carbon dioxide to form an admixture including carbonate and/or bicarbonate.

A method of sequestering a greenhouse gas is described, which comprises: (i) providing a solution carrying a first reagent that is capable of reacting with a greenhouse gas; (ii) contacting the solution with a greenhouse gas under conditions that promote a reaction between the at least first reagent and the greenhouse gas to produce at least a first reactant; (iii) providing a porous matrix having interstitial spaces and comprising at least a second reactant; (iv) allowing a solution carrying the at least first reactant to infiltrate at least a substantial portion of the interstitial spaces of the porous matrix under conditions that promote a reaction between the at least first reactant and the at least second reactant to provide at least a first product; and (v) allowing the at least first product to form and fill at least a portion of the interior spaces of the porous matrix, thereby sequestering a greenhouse gas.

There is provided a process for the capture and sequestration of carbon dioxide that would otherwise enter the atmosphere and contribute to global warming and other problems. CO₂ capture is accomplished by reacting carbon dioxide in flue gas with an alkali metal carbonate, or a metal oxide, particularly containing an alkaline earth metal or iron, to form a carbonate salt. A preferred carbonate for CO₂ capture is a dilute aqueous solution of additive-free (Na₂CO₃). Other carbonates include (K₂CO₃) or other metal ion that can produce both a carbonate and a bicarbonate salt. Examples of suitable metal oxides include several alkaline earths including CaO and MgO. The captured CO₂ is preferably sequestered using any available mineral or industrial waste that contains calcium magnesium or iron in non-carbonate forms, or iron in the Fe⁺² oxidation state.

Compositions comprising synthetic rock, e.g., aggregate, and methods of producing and using them are provided. The rock, e.g., aggregate, contains CO₂ and/or other components of an industrial waste stream. The CO₂ may be in the form of divalent cation carbonates, e.g., magnesium and calcium carbonates. Aspects of the invention include contacting a CO₂ containing gaseous stream with a water to dissolve CO₂, and placing the water under precipitation conditions sufficient to produce a carbonate containing precipitate product, e.g., a divalent cation carbonate.

In a preferred embodiment, the invention relates to a process of sequestering carbon dioxide. The process comprises the steps of: (a) reacting a metal silicate with a caustic alkali-metal hydroxide to produce a hydroxide of the metal formerly contained in the silicate; (b) reacting carbon dioxide with at least one of a caustic alkali-metal hydroxide and an alkali-metal silicate to produce at least one of an alkali-metal carbonate and an alkali-metal bicarbonate; and (c) reacting the metal hydroxide product of step (a) with at least one of the alkali-metal carbonate and the alkali-metal bicarbonate produced in step (b) to produce a carbonate of the metal formerly contained in the metal silicate of step (a).

Disclosed is a novel form of particulate precipitated aragonite, and a novel process for producing it.

An FCC catalyst which not only deactivates catalyst poison metals, such as nickel, vanadium and the like, in feedstock oils, inhibits the generation of hydrogen or coke, has excellent cracking activity and bottom oil-treating ability, and can yield a gasoline and LCO fraction in high yields, but also retains the performances on a high level over long and has an improved catalyst life; and an FCC method using the catalyst. The FCC catalyst has a compound of a bivalent metal or of bivalent and trivalent metals showing an XRD pattern of a carbonate of the bivalent metal; an inorganic oxide matrix and the compound dispersed therein; or an inorganic oxide matrix and the compound dispersed therein together with a crystalline aluminosilicate zeolite, and relates to an FCC method in which at least one of the catalysts are used in combination with an FCC catalyst obtained by evenly dispersing a crystalline aluminosilicate zeolite in an inorganic oxide matrix.

Processes for use of a controlled continuous high pressure multiple reactant streams flowing into a chemical mixer/reactor. Individual reactant streams are pressurized to about 8,000 to 50,000 psi and achieve velocities up to about 250 meters/second in the final stage of the chemical mixer/reactor.

Non-cementitious CO₂ sequestering compositions are provided. The compositions of the invention include a CO₂ sequestering additive, e.g., a CO₂ sequestering carbonate composition. Additional aspects of the invention include methods of making and using the non-cementitious CO₂ sequestering compositions.

Basic magnesium carbonate comprising a tubular aggregated particle of flaky fine crystals.

The present invention relates to the preparation process of high purity aragonite type calcium carbonate whisker. The present invention prepares aragonite type calcium carbonate whisker with lime or slaked lime as main material and magnesium salt as crystal salt controlling agent and through a CO2 carbonating process. The process features the repeated use of the magnesium salt solution and the homogeneous replenishment of lime slurry during carbonating reaction. The process has low production cost, less environmental pollution and high calcium carbonate whisker yield, and the prepared calcium carbonate whisker has high purity and high length/diameter ratio. The process is suitable for industrial production of calcium carbonate whisker.

The invention discloses a method for dissolving red mud. The method comprises the following specific steps of: mixing Bayer process red mud with white lime in the mass ratio of 1:(0.3-0.9); stirring at the temperature of 80-140 DEG C for reacting for 1-15 hours for calcifying, transforming and dealkalizing; mixing calcified, deformed and dealkalized Bayer process red mud with clear water or a low-concentration sodium aluminate solution in an enclosed container; introducing CO2 into the container to obtain calcified slag containing calcium silicate, calcium carbonate and aluminum hydroxide serving as main components; and extracting aluminum hydroxide from the calcified slag by using a sodium hydroxide solution or an aluminum hydroxide solution. In the method disclosed by the invention, the structure and composition of red mud are changed by adopting calcification transformation and pressurizing calcification transformation methods, so that dealkalization and extraction of aluminum can be realized; and iron is extracted properly, so that the structure and the composition of red mud can meet the requirements of cement production, and the aim of dissolving red mud on a large scale at low cost is fulfilled.

When spherical calcium carbonate is produced by blowing a carbon dioxide gas or a carbon dioxide-containing gas into an aqueous suspension containing calcium hydroxide to react them, after start of the reaction, an aqueous solution or suspension of a water-soluble phosphoric acid compound or a water-soluble salt thereof is added to the reaction mixture when carbonation ratio reaches 2 to 10%, and the reaction is further allowed to continue at a low gas blowing rate of 1.0 NL/minute or lower (step (a)). Subsequently, an aqueous suspension containing calcium hydroxide and an aqueous solution or suspension of a water-soluble phosphoric acid compound or a water-soluble salt thereof are added to the reaction mixture, and a carbon dioxide gas or a carbon dioxide-containing gas is introduced to allow to react and thereby produce spherical calcium carbonate having a mean particle diameter of 10 μm or larger. This production method is performed under high velocity revolution from the start of the reaction to the end of the step (a) This method provides calcite type spherical calcium carbonate showing high brightness and small friction coefficient, and having a shape comparatively close to a true sphere and a mean particle diameter of 10 μm or larger.

The invention relates to an overall treatment method of steel works sintering dust, which is characterized by comprising the following steps: carrying out stage treatment on electrically precipitated dust in a sintering head, conveying the electrically precipitated dust produced in a primary electric field directly to a sintering field (a stock yard or a material distribution room) for material application in case of sintering; mixing the electrically precipitated dust produced in a subsequent electric field and then carrying out stirring pulping, gradient magnetic separation, carbon selection by flotation and solid-liquid separation; when the solid-liquid separation is finished, using the obtained potassium solution for producing potassic fertilizer and extracting lead product from the obtained tailing slurry.The method of the invention has the advantages that different process routes are adopted to effectively recover and comprehensively utilize contained multiple valuable resources such as ferrum, carbon, potassium, lead and the like according to different contents of alkali metal such as potassium and sodium and heavy metal compounds such as lead, zinc and copper in different electric field precipitated dust in a sintering head electric precipitator.

The invention discloses a preparation method of nano-calcium carbonate SCC-2 special for a silicone sealant, belonging to the technical field of inorganic chemical industry. According to an adopted technical scheme, the method comprises the following steps of: calcining limestone, crushing to obtain CaO; digesting, refining and aging the CaO in a hot state in the ratio of 1:4.8 of CaO to H2O; adding 1 percent of white granulated sugar crystal form control agent for undergoing a carbonation reaction to obtain CaCO3 slurry; performing activation surface treatment; and dehydrating, drying, crushing and degrading to obtain a nano-active CaCO3 product of 60-100 nanometers. The crystal form, size, regularity, oil absorption value and pH value of CaCO3 are controlled, so that 'hard aggregation' among particles is avoided from a surface modification production process, and the product has low oil absorption value and high bulk specific weight and has high dispersity in polymers.

The invention provides methods and apparatuses for removing carbon dioxide from a gas stream. In particular, the invention provides methods and apparatuses for absorbing carbon dioxide from a coal-fired boiler flue gas stream using an absorbing solution and for regeneration of an alkaline component used in the absorbing solution. In one embodiment, the invention provides a method for removing carbon dioxide from a gas stream by contacting a gas stream containing carbon dioxide with an alkaline liquid stream; absorbing at least a portion of the carbon dioxide into the alkaline liquid stream to produce absorbed carbon dioxide; and catalyzing a reaction of the absorbed carbon dioxide to a form of carbonate.

A process for preparing calcium carbonate with actual forms (such as spindle, petal, needle, flake, ball fibre, etc.) features that in the supergravity field condition of rotating bed and under the existance of crystal form controlling agent and crystal seeds, the suspension of calcium hydroxide and CO2-contained raw gas take part in carbonifying reaction. Its advantage is controllable granularity and form.

Methods and apparatus for the production of low sodium lithium carbonate and lithium chloride from a brine concentrated to about 6.0 wt % lithium are disclosed. Methods and apparatus for direct recovery of technical grade lithium chloride from the concentrated brine are also disclosed.

The invention relates to a method for preparing nanometer calcium carbonate, in particular to a method for preparing nanometer calcium carbonate special for water soluble ink by a wet method. The method comprises the following steps: calcining and smashing limestone to prepare calcium oxide, classifying the calcium oxide, choosing fine quality calcium oxide to be slaked in a gyratory slaker, be aged twice and carbonized twice to prepare calcium carbonate. The method is characterized in that the calcium oxide undergoes slaking in the gyratory slaker and first aging, is added with a crystal control agent, undergoes second aging after undergoing first bubbling carbonation and is added with a material looseness modifier and a surface treatment agent to carry out second modification. The method farthest utilizes the low-grade limestone to prepare the nanometer calcium carbonate product special for water-based ink, with mean grain size of 10-40nm and specific surface of 40-70m/g and enhances the transparency and cohesive force of the ink.

The process of preparing high purity light calcium carbonate fine powder with carbide residue includes reacting carbide residue as one kind of industrial waste directly with ammonium chloride solution to produce mixture solution of calcium chloride and ammonia water, filtering, introducing CO2 gas for carbonating reaction, filtering the produced slurry, water washing the filter cake and stoving to obtain calcite type spherical light calcium carbonate fine powder, and circulating ammonium chloride solution for reuse. The present invention has simple technological process, lowered production cost, high product purity and high product quality.

The invention provides a preparation method of cubic ultra-fine calcium carbonate particles. The method comprises the following steps: (1) adding a nucleation promoter to calcium hydroxide suspension liquid, wherein the nucleation promoter is selected from more than one of glucose, sucrose or sodium citrate; (2) carbonizing by introducing carbon dioxide until the pH value is 8-12, adding a crystal modifier and ageing for 0.5-10 hours, wherein the crystal modifier is selected from one of sodium chloride, sodium carbonate, sodium bicarbonate or sodium hydroxide; (3) further introducing carbon dioxide and carbonizing until the pH value is 6.5-7.0; (4) coating by adding a coating agent, filtering and drying to obtain a product, wherein the coating agent is selected from a resin acid, a resin acid alkali metal salt, a fatty acid or a fatty acid alkali metal salt. According to the calcium carbonate particles, the particle sizes are 90-180nm, the calcium carbonate particles are in a cubic shape, and the specific surface area is 10-18m<2>/g. Thus, the cubic ultra-fine calcium carbonate particles can be used as functional fillers in coating, rubber, plastic and sealant industries.

A method and apparatus for the production of calcium carbonate and calcium silicate in common superatmospheric reactors. Multiple reactors can be provided for switching production between reactors, and advantageously utilizing process waste heat. On site production of both PCC and Calcium Silicate Hydrates is thus achieved in a paper mill.

The invention relates to a method for preparing white carbon black cogeneration nanometer calcium carbonate by integrally utilizing micro silicon powder, which belongs to the technical field of integrative utilization of silicon iron alloy industrial waste resources and industrial kiln gas carbon dioxide. The method comprises the following process steps that: micro silicon powder is dissolved by sodium hydroxide hot alkali for preparing water glass; lime is prepared through lime stone calcination, and carbon dioxide raw material gas is released; precipitated silica is prepared through water glass carbonization; carbonization filter liquid is subject to sodium carbonate causticization for preparing sodium hydroxide solution to coproduce nanometer calcium carbonate; and the sodium hydroxide solution is circulated to a hot alkali dissolving and boiling kettle for dissolving micro silicon powder to prepare water glass. The method has the advantages that the process circulation of integrally utilizing the micro silicon powder for preparing the white carbon black cogeneration nanometer calcium carbonate is realized, and a new method is provided for goals of changing metallurgy chemical industrial waste materials into resources and utilizing the waste materials at high value.

A fine pore formation agent for a porous resin film is provided which comprises inorganic particles satisfying (a) 0.1≦D50≦1.5 (μm) (D50: average particle diameter of particles in 50% cumulative total by weight from the larger particle side by micro-track FRA), (b) Da≦20 (μm) (Da: maximum particle diameter by micro-track FRA), (c) 3≦Sw≦60 (m²/g) (Sw: BET specific surface area measured by nitrogen adsorption method), (d) Ir≦1.0×10⁵ (Ω·cm) (Ir: volume resistivity (Ω·cm).

The fine pore formation agent for a porous resin film is capable of providing a resin composition giving a porous resin film useful in uses for electric parts such as capacitors and battery separators.

A method for forming a silica coating on at least a portion of the surface of alkaline earth metal carbonate particulates in aqueous suspension and the silica-coated alkaline earth metal carbonate so produced are claimed. The claimed method consists of allowing soluble silicate ions in the aqueous phase to slowly react with the alkaline earth metal carbonate surface to form silica micro-particulates on the surface. This silica coating confers upon the composition unique properties among which are pronounced thixotropic behavior when incorporated into an aqueous suspension and increased oil absorption when dry. The pigment produced by this method is especially suited for use as a filler in paper.

Disclosed is an additive for a plastic, comprising fine particles obtained by calcination and slaking of a dolomite which exhibits two endothermic peaks in the differential thermal analysis, said fine particles containing calcium carbonate, magnesium carbonate, magnesium oxide, calcium hydroxide and magnesium hydroxide as main chemical components and also containing an ignition loss component in an amount of 10 to 40% by weight based on the weight of said fine particles. A plastic hating hydrogen chloride scavenging properties and antimicrobial properties imparted by incorporating the additive for a plastic is also disclosed.

The invention provides a new method which takes carbide slag, quick lime or slaked lime as calcium material to react with amino acids for preparing fine calcium carbonate. The method provides a very good scheme for the problems dealing with industrial waste carbide slag, so the method has very good environment-friendly, social and economic benefits.