30 results about "Tricalcium aluminate" patented technology

The invention belongs to the technical field of building materials, and particularly relates to a silicon-aluminum material as well as a preparation method and application thereof. The silicon-aluminum material comprises 10-65 parts by weight of red mud, 20-60 parts by weight of slag powder, 0-20 parts by weight of Portland cement clinker, 0.1-8 parts by weight of an exciting agent and 5-15 parts by weight of an expanding agent; wherein the expanding agent is prepared from the following components in percentage by mass: 0 to 60 weight percent of aluminum sulfate, 0 to 70 weight percent of carbide slag, 0 to 70 weight percent of tricalcium aluminate, 0 to 60 weight percent of calcium sulphoaluminate and 0 to 60 weight percent of gypsum, and the content of at least two components in the expanding agent is not 0. The silicon-aluminum material with specific components and content can give consideration to both high strength and low shrinkage rate, and when the silicon-aluminum material is used in cement mortar, the compactness of cement can be enhanced and cracking can be prevented, so that the material can be used for a long time.

The invention discloses a fiber concrete preparation for a pavement, a preparation method thereof and a pavement construction method, relates to the technical field of road construction, and solves the problems of poor elasticity, durability and other performances of the existing pavement. Comprising a binding material composed of Portland cement, granulated blast furnace slag powder and silica fume, aggregate composed of continuous graded broken stone and machine-made sand, composite fiber composed of basalt fiber and polyvinyl alcohol fiber, a functional additive composed of a water reducing agent, a water-retaining agent and a defoaming agent, a catalyst composed of nano-silica and tricalcium aluminate, and water. The pavement construction method comprises the following steps: paving the preparation within 30 minutes, vibrating by adopting a high-frequency vibrator, leveling by adopting a laser leveling machine, covering with geotechnical cloth, and maintaining under standard conditions. The method can be applied to pavement construction, and is particularly suitable for severe pavement scenes such as severe cold and heavy load.

The invention discloses a special cementitious material for microwave-heated concrete, a preparation method thereof, and an application thereof, relating to the technical field of building materials. The cementitious material comprises components such as fly ash, steel slag, high-iron phase Portland cement clinker, high-belite sulfate cement clinker, gypsum, waste residue, solid waste, graphene, palmitic acid, and a water reducer. The high-iron phase Portland cement clinker contains more than 20% tetracalcium aluminoferrate and less than 3% tricalcium aluminate; the high-belite sulfate cement clinker contains more than 45% dicalcium silicate and 30-50% calcium sulfoaluminate. The cementitious material is made from specific solid waste, has excellent compressive strength, low resistivity, and high microwave heating efficiency, and can be used to prepare microwave-heated concrete.

This invention discloses an additive with chloride-fixing and toughening functions, its preparation method, and its application. The additive uses tricalcium aluminate and sodium acrylate as main raw materials. Under alkaline conditions, a wet grinding process hydrates tricalcium aluminate to form a calcium-aluminum layered bimetallic hydroxide structure, allowing acrylate atoms to intercalate into the interlayer, forming a stable organic-inorganic composite structure. When applied to cement-based materials, the layered structure reacts with chloride ions to generate chloride-containing hydration products, achieving chloride ion solidification. Simultaneously, the organic components in the composite structure undergo polymerization under the action of an initiator, forming a polymer network in the cement matrix, thereby improving the material's toughness. When added to cement-based materials at 1-5% of the cementitious material mass, the 28-day flexural strength can be increased by 38%-113%, and the 28-day chloride ion solidification rate can be increased by 17%-23%, while maintaining good workability. This invention achieves the simultaneous introduction of chloride ion solidification and material toughening functions through a single additive, simplifying the material system. It is suitable for cement-based materials containing endogenous chloride ions and has good engineering application prospects.

The invention relates to the technical field of cracking catalysts, in particular to a high-activity coal gangue cracking catalyst modification process which comprises the following steps: crushing coal gangue, spraying an alkaline pretreatment solution on the surface, and roasting to obtain thermally activated coal gangue powder; soaking the thermally activated coal gangue powder in an acidic treatment solution, heating in a constant-temperature water bath, washing, and drying to obtain acid modified coal gangue powder; soaking the acid-modified coal gangue powder in a metal salt solution, fully dipping through ultrasonic treatment, and drying to obtain high-activity coal gangue powder; and mixing the high-activity coal gangue powder with tricalcium aluminate hexahydrate and water, performing spray drying to generate microspheres, and calcining the microspheres in a kiln to obtain the high-activity coal gangue cracking catalyst. According to the high-activity coal gangue cracking catalyst, through matching and combination of the raw materials and the preparation steps, the catalytic activity of the catalyst can be improved, the internal structure of coal gangue is improved, the mechanical strength is enhanced, and the service life is prolonged.

The invention discloses a sulfate corrosion resistant method for concrete, and relates to the technical field of civil engineering materials and durability, and the method comprises the following steps: preparing matrix concrete: adopting modified Portland cement with tricalcium aluminate content of 6-8% as a cementing material, and doping a composite mineral admixture accounting for 20-28% of the total mass of the cementing material, the composite mineral admixture is composed of nano metakaolin and superfine slag according to the mass ratio of 1: (1.2-1.5); hydrophobic nano silicon dioxide aerogel particles with the particle size of 50-200 nm and the doping amount of 1.5-2.5 kg / m < 3 > are implanted into the depth interval of 0-15 mm of the concrete surface layer, meanwhile, a shape memory alloy micro wire mesh is embedded and is made of nickel-titanium alloy, the wire diameter is 0.1 mm, and the mesh density is 4 * 4 / cm < 2 >; and in-situ reaction coating generation: alkali-activated geopolymer slurry is sprayed after pouring forming, the modulus of water glass is 1.6-1.8, the solid content is larger than or equal to 65%, and an inorganic-organic hybrid protective layer matched with the thermal expansion coefficient of a concrete matrix is formed through curing.

The present invention relates to the technical field of medium-heat cement, and discloses a medium-heat tensile cement and a preparation method thereof, comprising calcium oxide, calcium silicate, dicalcium silicate, tricalcium silicate, tricalcium aluminate, tetracalcium aluminoferrate, metakaolin, iron ore powder, modified cotton stalk fiber, modified nano-silicon dioxide, sulfur trioxide and magnesium oxide. The present invention effectively improves the early compressive strength, flexural strength and splitting tensile strength of cement by using modified cotton stalk fiber, and reduces the damage of modified cotton stalk fiber under alkaline conditions by using nano-silicon dioxide, thereby improving the durability of cement. At the same time, the amide group grafted on the surface of the modified nano-silicon dioxide reacts with the hydroxyl group on the surface of the modified cotton stalk fiber to form a strong hydrogen bond, thereby further improving the tensile strength of cement and improving the mechanical properties of cement.

The invention discloses a refractory mortar sheet-shaped prefabricated body as well as a preparation method and a construction method thereof, and belongs to the technical field of refractory mortar. The refractory mortar flaky preform is prepared from the following raw materials: 70 to 80 percent of porous bauxite clinker, 5 to 10 percent of quartz powder, 5 to 10 percent of silica powder, 0.5 to 1.0 percent of isothiazolinone derivative, 3 to 6 percent of passivated aluminum powder, 0.1 to 0.3 percent of tricalcium aluminate and 3 to 5 percent of yellow dextrin. 10-15% of a polyvinyl alcohol solution is added; the mass ratio of polyvinyl alcohol to water in the polyvinyl alcohol solution is 1: (18-20); the preparation method comprises the following steps: uniformly mixing the raw materials, pressing into slices and curing. The refractory mortar sheet-shaped prefabricated body has a rich microporous structure, has heat insulation property and moisture permeability, also has good forming strength and good plasticity and high-temperature performance after wetting, realizes a construction mode of on-site unpacking and ready-to-use, greatly improves the construction efficiency, and is suitable for high-efficiency masonry of industrial kiln masonry.

The application discloses a kind of high-strength slow-setting silicate cement clinker and preparation method thereof, its mineral composition includes C3S>63%, C2S 1.09%‑13.39%, C3A<4.7%, C4AF 13.73%‑14.36%, free calcium oxide content in clinker is below 1.5%.The application reduces aluminum rate from the angle of mineral composition design, improves limestone saturation coefficient, and prepares a kind of low alumina tricalcium (C3A<4.7%), high silicate tricalcium (C3S>63%) clinker using industrial solid waste coal gangue, which can be prepared under existing cement production process, and has the characteristics of high strength, stable expansion and shrinkage performance, low early hydration heat release, long setting time and easy to control, etc.

The present invention provides a low chloride ion leaching gypsum mortar and a preparation method thereof. The gypsum mortar comprises the following components by weight: 65-80 parts of desulfurized gypsum, 3-6 parts of tricalcium aluminate, 3-5 parts of tetracalcium aluminoferrate, 10-15 parts of fly ash, 5-10 parts of hydrotalcite, 0.2-0.5 parts of rubber powder and 0.01-0.03 parts of retarder. The preparation method comprises the following steps: adding rubber powder and retarder into water, stirring evenly with a stirrer to obtain an admixture solution; mixing desulfurized gypsum, tricalcium aluminate, tetracalcium aluminoferrate, fly ash and hydrotalcite powder evenly to obtain a mixed powder; mixing the admixture solution and the mixed powder evenly to obtain a low chloride ion leaching gypsum mortar. The present invention adopts the chemical combination of tricalcium aluminate, tetracalcium aluminoferrate and chloride ions, and utilizes the physical adsorption of hydrotalcite porous medium to reduce the chloride ion leaching rate, and simultaneously utilizes the addition of fly ash to increase the compactness of gypsum mortar, reduce chloride ion transmission, and further reduce the chloride ion leaching rate.

The invention provides a cement clinker doped with barium slag and a preparation method and application thereof, and relates to the technical field of cement clinker preparation, the cement clinker is prepared from a main material and an admixture raw material component, the main material is composed of limestone, sandstone, clay, an iron material and barium slag, the admixture is composed of 3% of coal ash, and the admixture is composed of 1% of calcium carbonate. The main material comprises the following raw material components in percentage by weight: 79-83% of limestone, 0-3% of sandstone, 11-14% of clay, 1.9-2.4% of ferrous material and 1-7% of barium slag; according to the invention, barium slag is introduced as a modification component based on a traditional cement clinker formula system, so that multiple technical benefits can be realized at the same time: seed crystal doping, cement 28d strength improvement, orthorhombic system tricalcium aluminate content reduction, cement use performance improvement and the like, and the optimal barium slag doping amount is determined to be 5%; the prepared cement clinker and cement have the characteristics of high later strength, good use performance and the like.

The invention discloses a special cementing material for microwave heating concrete as well as a preparation method and application thereof, and relates to the technical field of building materials, the cementing material comprises fly ash, steel slag, high-iron-phase Portland cement clinker, high-belite sulfate cement clinker, gypsum, waste residue, solid waste, graphene, palmitic acid, a water reducing agent and the like. The content of tetra calcium aluminoferrite in the high-iron-phase Portland cement clinker is greater than 20%, and the content of tricalcium aluminate is less than 3%; in the high belite sulfate cement clinker, the content of dicalcium silicate is greater than 45%, the content of calcium sulphoaluminate is 30-50%, and a cementing material is prepared from specific solid wastes, has excellent compressive strength, low resistivity and relatively high microwave heating efficiency, and can be used for preparing microwave heating type concrete.

This invention discloses a method for designing the composition of a limestone powder-containing TSA-resistant cementitious material for tunnel concrete, comprising the following steps: Step 1, determining the TSA erosion environment level of the tunnel structure concrete; Step 2, determining the mass dosage W of highly active cementitious material per cubic meter of concrete. CM Step 3: Determine the mass percentage R of tricalcium aluminate in the highly active cementitious material. C3A Step 4: Determine the type and composition of the high-activity cementitious material; Step 5: Determine the mass quantity (W) of stone powder used as a low-activity cementitious material per cubic meter of concrete. LS Step 6: Determine the composition and mass percentage of cementitious materials in a single cubic meter of concrete. Since all materials involved in this method are mature and widely used, they are readily available, their quality is controllable, and their indicators are easy to obtain. Furthermore, this method can provide corresponding material composition designs for different low-temperature sulfate attack environments, making it highly targeted, covering most low-temperature sulfate environments, and has broad prospects for widespread application.

The invention belongs to the technical field of cementing materials, and particularly relates to a carbon-based modified high-durability alkali-activated cementing material and a preparation method thereof. The raw materials comprise mineral powder, steel slag, molybdenum tailings, a composite activator, lignosulfonate, boric acid, citric acid, calcium stearate, tricalcium aluminate, nano silica fume and modified carbon fibers. The modified carbon fibers are added, the carbon nanotubes are grafted on the surfaces of the carbon fibers, the surface roughness is increased, and the binding force between the modified carbon fibers and a hydration product is increased, so that the binding force between the modified carbon fibers and the hydration product is greatly increased, and the bonding effect between the modified carbon fibers and the alkali-activated cementing material is enhanced; further, the breaking strength of the material is enhanced.

The invention discloses a steel structure aqueous on-rust coating cathodic protection, self-repairing and self-cleaning anticorrosive paint, which comprises a component A and a component B. The component A comprises deionized water, aqueous fluorocarbon acrylic resin, tannic acid, nanometer aluminum triphosphate and a nanometer conductive polymer. The component B is prepared from ZnAl-based alloy powder, nano rutile type titanium dioxide and nano tricalcium aluminate. The coating disclosed by the invention adopts water as a solvent, does not contain volatile organic compounds, and is beneficial to environmental protection and health protection; the rust transforming agent in the paint can stabilize rust, prevent rust and coat with rust; the nano conductive polymer material enables the coating anticorrosive coating to have a self-repairing function; the ZnAl-based alloy powder not only can effectively play a long-term cathode protection role, but also can improve the shielding protection role of the coating; the nano rutile type titanium dioxide has the functions of self-cleaning and prolonging the anti-corrosion service life of the coating. The coating disclosed by the invention can provide safe, long-acting and convenient-to-construct anti-corrosion protection for a steel structure.

The invention discloses a metallurgical solid waste gel material which comprises the following components in percentage by mass: 40-60% of superfine slag powder, 5-15% of building gypsum powder, 5-20% of stainless steel slag powder, 5-10% of fly ash and 1-8% of coking desulfurization ash, the superfine slag powder is prepared by conveying blast furnace water-quenched slag generated by ironmaking into a storage tank through a belt and then grinding the blast furnace water-quenched slag into a vertical mill; according to the invention, sodium sulfate of coking desulfurization ash is utilized to excite condensation and hardening of superfine slag powder, and development of compressive strength is promoted. Sodium sulfate can react with calcium in the stainless steel slag powder in the early stage to generate gypsum and sodium hydroxide, sufficient gypsum is provided for reacting with tricalcium aluminate, a large amount of ettringite is generated in the early stage, and the bonding strength is enhanced; compared with the common method using desulfurized gypsum, the addition of the building gypsum powder can adjust the setting time of the cementing material, and can flexibly, conveniently and quickly adjust the application in different scenes.

The invention discloses a preparation method and application of a cement-based material early strength agent. The method comprises the following steps: inactivating, cleaning, drying and crushing periplaneta americana; soaking the crushed periplaneta americana powder in an AC modification liquid for modification, filtering, taking the powder, and cleaning; adding the powder into deionized water to prepare turbid liquid, and placing the turbid liquid in an ultrasonic environment for ultrasonic treatment; putting the turbid liquid into a centrifugal machine to be centrifuged; and taking the lower-layer precipitate, cleaning, drying, grinding and sieving to obtain powder, namely the cement-based material early strength agent. The modified periplaneta americana powder is used as the cement-based material early strength agent, amino (-NH2) of lysine contained in the modified periplaneta americana powder is combined with tricalcium aluminate (C3A) in cement, formation of ettringite (AFt) is accelerated, and compactness of early hydration products is optimized. Meanwhile, as a nucleation site of C-S-H gel, rapid crystallization of the C-S-H gel is promoted, so that the effects of improving the early compressive strength and reducing the setting time of the cement-based material are achieved.

A method for 3D printing of construction materials wherein a flowable composition containing hydraulic cement with low tricalcium aluminate (C3A) content (<5 wt.-%, preferably <3 wt.-%) and aggregates is conveyed to a deposition head and deposited layer-by-layer through an outlet of the moving deposition head. Prior to deposition, a yielding agent comprising aluminum chloride, its hydroxides, or mixtures thereof is added to increase the yield stress of the material compared to its state during conveyance, enabling successive layers to be placed on top of each other without deformation.

An insolubilizing material for specific harmful substances (heavy metals and the like), which is characterized by containing at least a high-alumina cement powder and a gypsum powder, the insolubilizing material for the specific harmful substance (such as a heavy metal) is preferably configured so that the ratio of the gypsum to 1 mole of tricalcium aluminate (C3A) in the high-alumina cement is within the range of 0.3-6.4 moles. The insolubilizing material for specific harmful substances (heavy metals and the like) can provide an insolubilizing material which, when applied to contaminated soil containing heavy metals and the like and / or fly ash and the like, has a useful effect of inhibiting elution of heavy metals and the like significantly quickly and quickly compared to conventional insolubilizing materials, and has a high practical value. It is possible to provide an insolubilizing material which is capable of effectively insolubilizing fluorine and / or boron, which is particularly difficult to insolubilize among heavy metals and the like when using conventional insolubilizing materials, and which exhibits a more useful effect.

The invention relates to the technical field of solid waste resource utilization, in particular to a high-value utilization method of calcium carbide slag and secondary aluminum ash. The method comprises the following steps: S1, mixing carbide slag and secondary aluminum ash in a mass ratio of (50-80): 100, then adding into water for hydrolysis, and after hydrolysis is finished, carrying out vacuum filtration and drying on slurry; s2, doping the fully dried hydrolyzed aluminum ash with 5-15 wt% of carbide slag, and calcining at 900-1100 DEG C to obtain a calcium aluminate clinker; and S3, leaching the calcium aluminate clinker in a sodium carbonate solution. The added carbide slag reacts with aluminum hydroxide generated by hydrolysis of metal aluminum and aluminum nitride to generate tricalcium aluminate hexahydrate, soluble villiaumite is fixed in hydrolyzed aluminum ash in the form of calcium fluoride, the calcination temperature of calcium aluminate clinker is reduced to 900-1100 DEG C, dodecacalcium heptaaluminate is generated through calcination, and the aluminum extraction rate can reach 93.2%.

The invention discloses a novel crystal containing ions such as Mg, Al and Ca and water and a preparation method of the novel crystal. The XRD diffraction peak of the crystal is unconventional, and the XRD diffraction pattern of the crystal has diffraction peaks at (1), (2), (3) and (4); the preparation method of the crystal comprises the following steps: adding deionized water into a material obtained by mixing tricalcium aluminate and magnesium oxide for hydration, putting a hydrated sample into a plastic bottle, filling nitrogen for sealing, then putting into a curing box for constant-temperature curing, and hydrating for 3 days, so that an obvious diffraction peak can appear, the MgO doping amount is 40% of the mass of tricalcium aluminate, the water-solid ratio is 10: 1, and the optimal curing temperature is 50 DEG C. The preparation method has universality, the preparation process is simple, and operation is easy.

The invention discloses high-toughness high-temperature well cementation cement, and relates to the technical field of oil and gas well cementation materials. The high-toughness high-temperature well cementing cement provided by the invention is prepared from the following components in parts by weight: 20 to 35 parts of tricalcium silicate, 40 to 55 parts of dicalcium silicate, 14 to 20 parts of tetra calcium aluminoferrite, 0.5 to 2 parts of tricalcium aluminate, 3 to 10 parts of calcium zirconate and 2 to 4 parts of gypsum. The high-temperature well cementation cement mainly solves the problems of poor toughness and unstable compressive strength of the high-temperature well cementation cement for deep and ultra-deep well cementation, and achieves the purpose of improving the toughness and strength stability of set cement by changing the mineral components of the cement.

The present invention relates to the technical field of admixtures for cement-based building materials, and in particular to an early-strength and shrinkage-reducing agent for ordinary portland cement, its preparation method and application. In the grinding process of amorphous tricalcium aluminate, an appropriate amount of boric acid is added, and calcium sulfate whiskers are added to precisely control the hydration process, improve the early strength of ordinary portland cement, reduce shrinkage, and further extract bismuth oxide from tungsten tailings sand particles and prepare a catalyst in combination with yttrium oxide to further improve the early shrinkage-reducing effect.

The application discloses a high-crack-resistance low-heat Portland cement and a preparation method thereof. The application belongs to the technical field of building materials and comprises, by weight, 81-92 parts of cement clinker, 2-7 parts of gypsum, 1-4 parts of an activator, and 5-17 parts of an adjusting material. Mineral components in the cement clinker comprise, by weight percentage, 30-40% of tricalcium silicate, 35-45% of dicalcium silicate, 3-8% of tricalcium aluminate and 14-17% of tetracalcium aluminoferrite. The adjusting material comprises, by weight percentage, 35-46% of bentonite, 31-40% of superabsorbent resin, 10-23% of hollow glass microbeads and 6-18% of alcohol amine auxiliary agent. The application can significantly improve the comprehensive performance of the low-heat Portland cement, so as to reduce the cracking risk of concrete in a severe and complex environment.

The embodiment of the invention provides a method for preparing a filter aid by activating lime milk, which comprises the following steps: carrying out first mixing on lime milk and Bayer process refined liquid to carry out pre-reaction to generate a primary filter aid; carrying out second mixing on the primary filter aid and crude liquid containing sodium aluminate to carry out deepening reaction, so that tricalcium aluminate crystals in the primary filter aid further grow in the crude liquid; carrying out solid-liquid separation on the liquid subjected to the second mixing to obtain a filter aid product; wherein the pre-reaction comprises the following parameters: the reaction temperature is 75-95 DEG C, the reaction time is 40 minutes to 3 hours, the reaction pressure is normal pressure, and the stirring speed is 50-150 revolutions per minute. Through the two stages of pre-reaction and deepening reaction, the generation and growth conditions of tricalcium aluminate crystals are optimized, and finally the technical problem of improving the filtering performance of the filter aid is effectively solved.

The invention discloses a biological filter aid for fine filtration of bauxite dissolved-out ore pulp and preparation and use thereof, and relates to the technical field of aluminum metallurgy and ore pulp treatment.The biological filter aid is a composite bio-based polymer water aqua and comprises a flocculating agent, a dispersing agent, a main stabilizer, an auxiliary stabilizer and deionized water, wherein the flocculating agent is mainly prepared from branched dextran. The filter aid is non-toxic and harmless, is biodegradable, and has the characteristics of high temperature resistance, strong alkali resistance and stable performance. The branched dextran can capture more than 90% of fine suspended matters under strong base and high temperature, so that the content of seminal fluid particles is lower than 20mg / L; the dispersing agent disperses calcium salt through chelation and charge repulsion to prevent local deposition and filter cloth blockage; the stabilizer can capture free radicals and combine with saccharides to form a protective layer, so that the system stability is improved. The filter aid improves the granularity of the hydrated tricalcium aluminate, so that the filtering capacity of the leaf filter is improved by 1-2 times, and the dosage of lime milk is reduced by more than 10%, thereby reducing the hydrolysis loss and improving the production efficiency.

The invention relates to the technical field of coatings, and particularly discloses a high-permeability wall reinforcing agent and a preparation method thereof. The high-permeability wall reinforcing agent is prepared from the following raw materials: high-permeability emulsion with a core-shell structure, temperature-sensitive reverse osmosis resin, a film-forming agent, ethylene glycol, a penetrant, an auxiliary agent, a composite salt-alkali capturing agent and deionized water, a core layer of the high-permeability emulsion with the core-shell structure is water-borne epoxy resin, and a shell layer of the high-permeability emulsion with the core-shell structure is silicone acrylic emulsion; the temperature-sensitive reverse osmosis resin is poly (N-isopropylacrylamide) grafted polyvinyl alcohol resin; the compound salt and alkali trapping agent is prepared by compounding hydrated tricalcium aluminate, hexamethylenetetramine and sodium alginate. According to the wall surface reinforcing agent disclosed by the invention, the two-way permeability of the reinforcing agent is greatly improved, the sealing performance of the reinforcing agent on a wall body base material is enhanced, the problems that the binding power of an interface layer is reduced, a leveling layer is hollowing and pulverization and the like caused by migration of saline-alkali substances in a humid environment are effectively solved, and the long-term stability of a wall surface decoration effect is guaranteed.

The invention relates to high-strength cement-slag-based foam concrete and a preparation method, and the high-strength cement-slag-based foam concrete comprises the following components in parts by mass: 30-70 parts of slag, 30-70 parts of cement, 5-10 parts of a crystallization inducer, 1-6 parts of cellulose, 1-3 parts of water-absorbent resin, 7-10 parts of fibers, 2-6 parts of a water reducing agent and 10-15 parts of a foaming agent. 3-7 parts of first ettringite and 1-3 parts of second ettringite; the first ettringite is prepared from a calcium source and aluminum sulfate under an alkaline condition, and the second ettringite is prepared from tricalcium aluminate and dihydrate gypsum through a mixed reaction. The first ettringite and the second ettringite are mixed to form mixed ettringite with different morphologies, the mixed ettringite is matched with cellulose to improve the foam stability and promote pore wall densification and crack reduction, so that the strength of the cement-slag based foam concrete is effectively improved, and shrinkage is reduced.

The present invention belongs to the technical field of building material admixtures and discloses a composite functional admixture for early strength and long-term collapse protection, its preparation method, and application. The preparation method comprises the following steps: 1) adding tricalcium aluminate, an activator, and a grinding medium to water, adjusting the pH and then grinding, and removing the grinding medium after grinding to obtain a suspension A; 2) adding the suspension A and a water reducer to a reactor, passing an inert gas through the reactor for protection, and reacting under heating and pressure to obtain a suspension B; 3) stirring and mixing the suspension B with a surfactant and limestone powder, and then ultrasonically dispersing the mixture to obtain the composite functional admixture for early strength and long-term collapse protection. When the composite functional admixture of the present invention is applied to supersulfated cement, it not only has excellent early strength performance, but also can achieve water reduction and long-term collapse protection, providing effective technical support for the large-scale application of supersulfated cement.

The application discloses a high-adaptability high-temperature well cementing cement and a high-temperature well cementing slurry, and relates to the technical field of well cementing materials for oil and gas wells.The high-temperature well cementing cement is composed of cement clinker and gypsum, and the mineral composition of the cement clinker comprises, in weight parts, 15-30 parts of tricalcium silicate, 6-15 parts of beta-dicalcium silicate, 38-55 parts of gamma-dicalcium silicate, 0.5-1.5 parts of tricalcium aluminate, 10-16 parts of tetracalcium aluminoferrite-titanium dioxide and 0.5-4 parts of calcium oxide; and the content of titanium dioxide in raw materials of the cement clinker is 1-2 percent in weight percentage.The application changes the mode of cement mineral composition, improves the adaptability of the cement to additives under high-temperature and high-pressure conditions, reduces the adjustment difficulty of the thickening time of the high-temperature well cementing slurry, improves the working performance and stability of the high-temperature well cementing slurry, and achieves the purpose of improving the construction safety and well cementing quality of deep well high-temperature well cementing operation.