221 results about "Ettringite" patented technology

The invention discloses a yellow phosphorus tailing-based mine filling material and application thereof. The yellow phosphorus tailing-based mine filling material comprises aggregate and a cementing material, the cementing material comprises the following components in parts by mass: 5-20 parts of red mud, 20-40 parts of yellow phosphorus slag, 10-30 parts of slag, 5-10 parts of fly ash, 5-10 parts of a compound exciting agent, 1-3 parts of an early strength agent and 2-5 parts of a water-retaining agent; wherein the compound exciting agent comprises the following components in parts by mass: 10-20 parts of sodium metasilicate, 30-40 parts of gypsum powder, 20-30 parts of sodium sulfate, 5-10 parts of carbide slag and 5-10 parts of silica fume; according to the invention, the raw materials are compounded and the specific exciting agent is subjected to depolymerization-polycondensation reaction to obtain a cementing material containing Aft (ettringite), C-S-H gel (hydrated calcium silicate gel) and C-A-S-H gel (hydrated calcium aluminosilicate gel), and finally, the mine filling material with high fluidity, low bleeding rate and high strength is obtained while yellow phosphorus tailing solid waste is treated.

The invention provides a concrete admixture with sulfate corrosion resistance and rust resistance functions. The concrete admixture is prepared from the following raw materials in parts by weight: 50-65 parts of fly ash, 8-12 parts of barium carbonate, 8-12 parts of barium hydroxide, 8-12 parts of mineral powder, 5-8 parts of modified hydrotalcite or hydrotalcite, 1-3 parts of nano silicon dioxide and 1-3 parts of calcium nitrite. Nano silicon dioxide is adopted as a compact component, the porosity of the material is reduced, the compactness of concrete is improved, sulfate in the environment is inhibited from being transmitted into the concrete, meanwhile, hydrotalcite is modified by polymaleic acid serving as a scale inhibition component, and the scale inhibition effect is improved through the dual effects of high adsorbability and slow release of the scale inhibition component of hydrotalcite. The preparation method has the advantages that generation of ettringite and gypsum in a sulfate radical environment is inhibited, calcium nitrite is added as a corrosion-inhibiting component, a protective film is formed on the surface of a reinforcing steel bar, the corrosion phenomenon of the reinforcing steel bar in a concrete structure is inhibited, and finally, the concrete admixture with sulfate corrosion resistance and corrosion-inhibiting functions is formed through compounding.

The invention discloses a solid waste-based cementitious material, which comprises the following raw materials based on 100% of the total mass percentage: 10% to 35% of pretreated pyrite tailing powder, 30% to 50% of granulated blast furnace slag powder, 15% to 30% of steel slag powder, and the remainder being gypsum powder. The invention heats the pyrite tailing at 300°C and ultrafinely grinds the pyrite tailing to cause an oxidation reaction of pyrite and pyrrhotite contained therein to generate sulfate minerals, thereby reducing the proportion of sulfide compounds in the tailing and reducing the risk of expansion and cracking of a hardened body of the solid waste-based cementitious material in the later stage. Moreover, the sulfate generated by oxidation and the gypsum contained in the pyrite tailing react with the steel slag and slag in the solid waste-based cementitious material to generate hydrated calcium silicate gel and calcium sulfonite, thereby improving the strength of the solid waste-based cementitious material.

The invention discloses nano ettringite particle reinforced aramid nanofiber aerogel as well as a preparation method and application thereof, and belongs to the technical field of aerogel. The preparation method provided by the invention comprises the following steps: dissolving a calcium source, an aluminum source and sulfate in water, adding a first surfactant, adjusting the pH value to 9-12, stirring for reaction, and after the reaction is finished, washing a solid product to be neutral to obtain nano ettringite particles; uniformly stirring and mixing the nano ettringite particles, para-aramid nanofibers, a second surfactant and a cross-linking agent in water to obtain an ettringite / aramid nanofiber dispersion liquid; the ettringite / aramid nanofiber dispersion liquid is sequentially subjected to concentration, directional freezing and freeze drying, and the ettringite / aramid nanofiber composite material is obtained. The preparation method disclosed by the invention is simple, the raw materials are easy to obtain, and the obtained nano ettringite particle reinforced aramid nanofiber aerogel has relatively high mechanical strength and thermal stability.

The invention belongs to the technical field of lithium slag resource utilization, and discloses a composite exciting agent for lithium slag as well as a preparation method and application of the composite exciting agent. The composite activator comprises the following components in parts by weight: 10-20 parts of an alkali activator, 10-20 parts of a sulfate activator, 15-30 parts of activated aluminum, 1-8 parts of a nano filler and 3-10 parts of a dispersant. An alkali activator and a sulfate activator are used as main materials, the advantages of the alkali activator and the sulfate activator are integrated, the alkaline environment promotes release of active silica-alumina species, the sulfate activator reacts with active aluminum to generate ettringite and other gel products, meanwhile, the active aluminum supplements aluminum ions, gel generation is promoted, and the gel is formed. The nano filler can fill pores and promote generation of C-S-H gel, and the dispersing agent can effectively disperse the active excitation component and the lithium slag.

The invention belongs to the technical field of grouting materials, and particularly relates to a hydrogel-cement-based composite grouting material capable of being used underwater, which is prepared from the following raw materials in parts by weight: 99.5 to 99.98 parts of cement, 0.02 to 0.5 part of reinforced hydrogel and 80 to 100 parts of water, the reinforced hydrogel is prepared by adopting a method comprising the following steps: (1) uniformly mixing a polyvinyl alcohol solution and a sodium alginate solution, and stirring in an ice-water bath; (2) adding a cement hydration product phase-ettringite fiber dispersion liquid, and uniformly stirring; (3) adding a calcium chloride solution, and carrying out cross-linking reaction; (4) crushing and drying the cross-linked product to obtain solid particles; and (5) soaking the solid particles in a mixed solution of glutaraldehyde and hydrochloric acid to obtain the reinforced hydrogel. According to the composite grouting material, the underwater dispersion resistance of the grouting material can be greatly improved, and the composite grouting material is especially suitable for underwater grouting repair engineering at a high flow rate.

The invention belongs to the technical field of industrial solid waste resource recycling, and discloses a nano composite filling material based on in-situ acid-base mutual modification enhancement and application thereof. According to the nano composite filling material, the alkalinity of the red mud and the acidity of the desulfurized gypsum are used for neutralization, the alkalinity of a system is reduced, a synergistic reaction is excited, a large number of ettringite crystals playing a key enhancing role are generated under the regulation and control of a nano material, and the ettringite crystals and a geopolymer form an interpenetrating network structure. The obtained slurry is low-viscosity and high-fluidity Newtonian fluid (diffusivity gt and 250 mm), the 7-day strength is larger than 2.0 MPa, the pH value is 7-9, and the fluorine ion concentration is lt; and the leaching of heavy metal ions is qualified, and the method is environment-friendly and safe. Efficient resource utilization of the red mud and the desulfurized gypsum is achieved, and the method is simple in process, low in cost and especially suitable for mine filling and engineering backfilling.

The invention discloses a multi-element solid waste synergistic excitation road material and a preparation method thereof. The multi-element solid waste synergistic excitation road material comprises the following raw material components: an activated matrix material (consisting of 85-90% of red mud, 7-15% of carbide slag and 3-5% of ardealite), and silica fume, 1-hydroxyethylidene-1, 1-diphosphonic acid, anhydrous sodium sulfate and water which respectively account for 4-6%, 0.2-0.4%, 0.8-1.2% and 30% of the mass of the activated matrix material. Pores are filled with silica fume in the raw materials, and C-S-H gel with low calcium-silicon ratio is generated, so that a water migration channel is blocked; hydroxyethylidene-1, 1-diphosphonic acid is chelated with free metal ions, saltpetering and ion interference are inhibited, and the ettringite structure is stabilized; carbide slag and ardealite cooperate to destroy a red mud silicon-aluminum network, accelerate dissolution of active ions and promote crystal generation; the anhydrous sodium sulfate accelerates formation of an ettringite framework through exogenous SO4 < 2->; the strength and water stability of the road material can be effectively improved. The raw materials are mainly industrial solid wastes, so that the consumption of natural resources is remarkably reduced, and the efficient collaborative consumption of a large amount of solid wastes is realized.

The invention relates to the technical field of concrete crack repairing agents, in particular to a triggered precipitation type concrete crack repairing agent as well as a preparation method and application thereof. The repairing agent is prepared from the following raw materials: sulphoaluminate cement, nano anhydrite with a core-shell structure, fluorine-phosphorus composite seed crystal, magnesium oxide, metakaolin and a water reducing agent, wherein the core-shell structure nano anhydrite is prepared by coating mesoporous silica with nano anhydrite, and the fluorine-phosphorus composite seed crystal is prepared from calcium fluoride and monocalcium phosphate through a hydrothermal reaction. According to the trigger precipitation type concrete crack repairing agent prepared by the invention, sulfate ions are slowly released through the core-shell structure nano anhydrite, the crystal form of ettringite is regulated and controlled through the fluorine-phosphorus composite seed crystal, the problems that a traditional repairing agent shrinks and falls off in the later period, the high-temperature strength is suddenly reduced, and the binding power is insufficient are solved, and the trigger precipitation type concrete crack repairing agent is suitable for concrete structure crack repairing and high-temperature environment engineering.

The invention relates to the technical field of cementing materials, and discloses low-carbon super-sulfate cement and a preparation method thereof.The low-carbon super-sulfate cement is prepared from, by weight, 80%-85% of blast furnace slag, 1%-5% of carbide slag and 10%-15% of desulfurized gypsum, the carbide slag serves as an alkali activator to destroy the slag structure and promote decomposition of a slag glass network body, and the desulfurized gypsum serves as an alkali activator to destroy the slag glass network body; the low-carbon super-sulfate cement prepared by the method has good early strength and later strength, and the carbon emission of the super-sulfate cement is reduced as the ettringite, the C-(A)-S-H gel and other hydration products are generated. And secondly, resource utilization of the industrial solid waste is combined with preparation of the cementing material, so that the risks of stockpiling and pollution of the industrial solid waste are effectively reduced, and comprehensive utilization of the industrial solid waste is promoted.

According to the preparation method, a composite alkaline solution with a specific pH value is adopted as a mineralization liquid phase medium, a silicon-aluminum activating agent, a mineralization accelerant and a crystal nucleus inducer are combined, CO2 gas is introduced into a liquid phase environment to directly trigger a depolymerization reaction of silicon-oxygen bonds and aluminum-oxygen bonds on the surfaces of fly ash particles, and the mineralization cementing material is obtained. The reaction conditions are easy to realize and control, the mineralized cementing material obtained by the preparation method is a non-cement-based material, and large-dosage fly ash gel is realized through mineralization-organic activation excitation. In addition, a gradient mineralization-directional crystallization process is initiated, the ion concentration and the temperature field of a mineralization system are regulated and controlled by stages, the coal ash is guided to dissociate, CO2 gas is introduced, a silicon-aluminum activating agent and a mineralization accelerant are added, and an intermediate is obtained; and generating the mineralized gelling material containing high-activity C-S-H gel and ettringite crystals from the calcium source substance according to a preset crystallization path.

The present invention relates to the technical field of supersulfate cement, and specifically discloses a calcium fluoroaluminate-modified high-stability supersulfate cement and its application. The raw materials of the supersulfate cement include the following components: 70-80 parts by weight of mineral powder, 10-15 parts by weight of gypsum, 5-10 parts by weight of calcium fluoroaluminate, and 1-2 parts by weight of modified diatomaceous earth. The modified diatomaceous earth is porous diatomaceous earth microspheres loaded with L-aspartic acid. The present invention utilizes the synergistic effect of the calcium fluoroaluminate and the modified diatomaceous earth to not only improve the early strength of the supersulfate cement, but also effectively improve the chemical stability of the hydration product ettringite (AFt), thereby improving the carbonation resistance of the supersulfate cement and alleviating the problem of long-term strength shrinkage.

The invention discloses a low-carbon masonry cementing material as well as a preparation method and application thereof. The low-carbon masonry cementing material is prepared from the following raw materials in parts by weight: 95-100 parts of ceramsite waste residue powder, 1-10 parts of magnesium aluminum silicate slag and 0-4 parts of clinker, the low-carbon masonry cementing material contains a large amount of amorphous active silicon, and under the direct excitation hydration action of the magnesium aluminum silicate slag component, the hydration rate of the low-carbon masonry cementing material is promoted, so that the low-carbon masonry cementing material has the characteristics of improved early and long-term strength, strong durability, high water retention rate and small hydration heat; besides, by adding the clinker, mineral components such as CaO, SiO2 and Al2O3 can be released and promoted to be subjected to a hydration reaction, C-S-H series hydrates and ettringite are generated, and the artificial stone is coagulated and hardened into the hard artificial stone at the normal temperature like cement.

The invention discloses marine concrete resistant to chlorine salt erosion and a preparation method thereof, and belongs to the technical field of building materials. The marine concrete is prepared from the following components in parts by mass: 280 to 350 parts of cementing material, 1100 to 1200 parts of aggregate, 150 to 180 parts of mixing water and 2.5 to 4.0 parts of high-efficiency water reducing agent, and the cementing material is prepared from 210 to 270 parts of ordinary Portland cement, 50 to 70 parts of superfine slag powder and 10 to 20 parts of modifier on the basis of the cementing material; on the basis of the modifier, the modifier is prepared from 30 to 45 parts of hexacalcium aluminoferrite, 25 to 35 parts of metaettringite, 20 to 35 parts of tobermorite, 3 to 6 parts of nano attapulgite and 2 to 4 parts of a nano composite material. The components can accelerate the early hydration of cement and the volcanic ash reaction process in the concrete hardening process, so that the concrete can form a compact microstructure in the curing period and cooperate with the curing effect of a hydration product on chloride ions, thereby remarkably improving the chloride ion penetration resistance of the concrete, prolonging the service life of the structure and improving the concrete quality. The method is suitable for port engineering, maritime work structures and buildings in salinized soil areas.

The invention relates to belite sulphoaluminate cement, the mass ratio of belite sulphoaluminate cement clinker to gypsum in the cement is (93-100): (0.5-7), the doping amount of gypsum is small, calcium sulphoaluminate can be promoted to be hydrated to generate more alumina gel, the alumina gel and dicalcium silicate generate hydrated calcium aluminosilicate, and the calcium aluminosilicate and dicalcium silicate are mixed to generate calcium aluminosilicate. Meanwhile, calcium sulphoaluminate is promoted to be hydrated to generate less ettringite and part of monosulfur hydrated calcium sulphoaluminate, and the early strength and the later strength of the cement are remarkably improved; the invention further relates to a low-temperature preparation method of the belite sulphoaluminate cement, the calcination temperature of the raw material is 1120-1200 DEG C and is lower than the calcination temperature in the prior art, and the preparation energy consumption of the cement clinker is reduced; according to the present invention, the early strength of the cement prepared through the calcination at the temperature of the present invention develops rapidly, the later strength of the cement slurry does not shrink with the increase of the hydration age, and the cement slurry still presents the stable increase trend, and the calcination temperature can increase the crystal defect of the calcium sulphoaluminate so as to easily provide the hydration activity of the calcium sulphoaluminate.

The invention provides an alkali-salt composite excited low-carbon hydraulic cementing material based on an element compatibility method as well as a preparation method and application thereof, and relates to the technical field of building materials. Silica-aluminum solid waste (mainly providing SiO2 and Al2O3), a sulfate solid waste exciting agent (mainly providing alkali metal oxide and / or alkaline earth metal oxide and SO3) and an alkaline solid waste exciting agent (mainly providing an alkalinity environment required by a hydration reaction) are used as main materials to generate a certain content of hydration product ettringite crystals and C (N)-A-S-H gel, and a compatibility method is adopted for design. The relative contents of Ca, Si, Al and S in a cementing system are adjusted while the alkaline solid waste excitant and the sulfate solid waste excitant are compounded and cooperated to excite the silicon-aluminum solid waste, so that the contents of ettringite crystals and hydrated calcium silicate gel in the whole hydration system are controlled, and the early strength and the later strength of the alkali-salt compounded and excited low-carbon hydraulic cementing material are improved.

This application relates to the technical field of concrete, and specifically discloses a high-strength concrete and its construction method. The high-strength concrete is obtained by subjecting a concrete mixture to in-mold curing. The concrete mixture comprises the following components in parts by weight: 160-165 parts of water, 370-380 parts of portland cement, 88-92 parts of mineral admixture, 58-62 parts of tetracalcium ferroaluminate powder, 720-730 parts of medium sand, 980-1020 parts of crushed stone, and 10.4-18.9 parts of polycarboxylate water reducer. By using tetracalcium ferroaluminate powder to partially replace portland cement in this application, the contents of the gel phase and ettringite increase. Under the combined action of the gel phase and ettringite, the anti-shrinkage performance of the high-strength concrete is enhanced, the cracking phenomenon is better controlled, thereby obtaining a lower compressive-to-flexural ratio, improving the toughness of the concrete, and being beneficial to the long-term service of the high-strength concrete.

The invention provides a retarding type polycarboxylate superplasticizer as well as a preparation method and application thereof, and belongs to the technical field of building material concrete admixtures. The retarding type polycarboxylic acid water reducing agent is prepared from the following raw materials in parts by weight: 300 to 400 parts of polyether macromonomer, 60 to 150 parts of unsaturated carboxylic acid micromonomer, 30 to 60 parts of unsaturated sulfonic acid monomer, 15 to 30 parts of alkylphenol polyoxyethylene ether phosphate, 1.5 to 12 parts of chain transfer agent, 2 to 15 parts of initiator, 15 to 50 parts of caustic soda liquid and 200 to 600 parts of solvent. The polycarboxylic acid water reducing agent product with the retarding characteristic is synthesized through an RAFT method, the binding force between phosphate radicals and calcium ions in a cement pore liquid of the preparation raw material alkylphenol polyoxyethylene ether phosphate is high, hydration of C3A and formation of ettringite are delayed, the retarding effect of the water reducing agent is enhanced, and the polycarboxylic acid water reducing agent has the anion characteristic and the nonionic characteristic and can be used as a water reducing agent. And the workability of the concrete is improved.

The invention discloses permeable mortar based on building waste composite ardealite and a preparation method of the permeable mortar. The mortar is prepared from the following components in parts by weight: 4 to 8 parts of 1.18 to 2.36 mm modified recycled aggregate, 16 to 22 parts of 2.36 to 4.75 mm modified recycled aggregate, 2 to 4 parts of cement, 2 to 4 parts of ardealite, 2 to 3 parts of water, 3 to 5 parts of microcapsules and 1 part of water reducing agent. According to the water-permeable mortar prepared by the invention, uniform distribution of C-S-H gel and ettringite is promoted through a multi-layer process synergistic effect, so that the microstructure is optimized, the later mechanical strength, durability and water permeability are improved, the setting time can be prolonged, the construction performance is ensured, the industrial requirements can be met, and the paving quality of ground materials such as water-permeable bricks is improved. According to the method, the resource utilization value of the building solid waste and the industrial byproduct gypsum is effectively improved, the production cost and the energy consumption can be remarkably reduced, a new technical path is provided for development of green building materials, reduction and resource application of the phosphogypsum and the building waste are achieved, and the method has a good application prospect.

The invention discloses a multi-source solid waste-based cementing material and a preparation method thereof, and relates to the technical field of solidified organic matter soft soil cementing materials. The cementing material is prepared from the following raw materials: carbide slag, desulfurized fly ash, yellow phosphorus slag, high-activity and high-stability steel slag, modified red mud, alkaline residues, desulfurized gypsum, mineral slag and calcium sulphoaluminate; the high-activity and high-stability steel slag is prepared by carrying out steel slag preliminary stabilization treatment and steel slag excitation activation on liquid steel slag; exciting and activating the steel slag: preparing high-activity and high-stability steel slag from the stabilized steel slag, the modified ettringite particles, aluminum sulfate, a polycarboxylate superplasticizer, hexadecyl triethyl ammonium bromide and potassium hydroxide; the modified red mud is prepared from red mud, magnesium hydroxide, N-methyldiethanolamine, desulfurized fly ash, calcium oxide and a ferric chloride solution; the modified ettringite particles are prepared from polyvinyl alcohol and N-beta-aminoethyl-gamma-aminopropyl trimethoxy silane as a modifying agent. The preparation method comprises the following steps: preparing the modified ettringite particles; according to the multi-source solid waste-based cementing material, the compressive strength and the water stability coefficient of the solidified organic matter soft soil are effectively improved.

The invention discloses a fire extinguishing agent special for forests and grassland, and belongs to the technical field of fire extinguishing agents. The fire extinguishing agent special for the forest grassland comprises the following components in parts by weight: 2-6 parts of a surfactant, 10-35 parts of modified blast furnace slag, 10-15 parts of organic modified ettringite, 0.5-4 parts of a foaming agent, 0.5-2 parts of a foam stabilizer, 0-10 parts of polyethylene glycol, 0-10 parts of urea, 0.5-1.0 part of a corrosion inhibitor, 3-5 parts of a composite flame retardant and 50-80 parts of water. The modified blast furnace slag is obtained by modifying blast furnace slag subjected to acid and alkali treatment by adopting carboxymethyl cellulose; the organic modified ettringite is modified by adopting tannic acid. According to the fire extinguishing agent special for the forest grassland, the raw materials are environmentally friendly and degradable, the cost is low, fire extinguishing and degradation can be rapidly conducted, fire spreading is effectively restrained, smoldering fire reburning is prevented, residues obtained after fire extinguishing are beneficial to vegetation recovery and water and soil loss prevention, the water utilization rate is increased, and the fire extinguishing agent can be suitable for any fire fighting equipment.

The invention discloses a basalt fiber modified cement-based capillary crystalline waterproof coating and a preparation method thereof, and relates to the technical field of waterproof coatings, the waterproof coating is prepared from Portland cement, surface modified basalt fibers, a gradient crystallization accelerator, nano-silica, a polycarboxylic acid water reducer, quartz sand, a functional additive and water; through composite pretreatment of the surface modified basalt fiber, a three-dimensional network structure is formed in the concrete, shrinkage stress is accurately compensated in combination with the magnesium oxide expanding agent, the crack resistance is remarkably improved, and the capillary adsorption effect of mesoporous nano-silica and the slow release design of the gradient crystallization accelerant are utilized to synergistically break through the penetration depth of active substances, so that the crack resistance of the concrete is improved. In addition, the viscosity of the slurry is reduced and the migration of active ions is accelerated by optimizing the molecular structure of the polycarboxylate superplasticizer, and the hydration process is regulated and controlled in cooperation with calcium lignosulphonate, so that the growth rate of ettringite crystals is multiplied, the crack repair can be completed in a short time, and the anti-permeability pressure is improved.

The invention relates to the technical field of building materials, and particularly discloses high-strength water-resistant anti-freezing plastering spraying mortar and a preparation method thereof. The high-strength waterproof anti-freezing plastering spraying mortar is prepared from the following raw materials in percentage by mass: 2.5 percent to 9.3 percent of high-free calcium belite sulphoaluminate clinker, 20 percent to 50 percent of gypsum, 9.4 percent to 56.5 percent of granulated blast furnace slag powder and 8 percent to 34 percent of lightweight aggregate. Through the design of the high-free-calcium belite sulphoaluminate clinker and the raw material design of the high-strength water-resistant anti-freezing plastering spraying mortar, the high-free-calcium belite sulphoaluminate clinker and the granulated blast-furnace slag powder have a synergistic effect, so that the types, the composition and the microstructure of hydration products of a gypsum-based material can be improved; the water-resistant and high-strength hydration products ettringite and C-(A)-S-H are greatly increased, and dense coating of the ettringite and C-(A)-S-H on dihydrate gypsum is realized, so that the problems of poor water resistance, poor freezing resistance and low strength of gypsum-based mortar are solved.

The invention discloses an anti-erosion multi-element solid waste synergistic red mud-based filling material and a preparation method thereof. The filling material is prepared from the following components in parts by weight: 60 to 80 parts of red mud, 18 to 30 parts of fly ash, 3 to 9 parts of desulfurized gypsum, 3 parts of cement, 0.3 to 0.7 part of water reducing agent, 0.3 to 0.9 part of fiber and 27 to 30 parts of water. Red mud is used for supporting a framework, an alkaline environment is provided, and Si-O and Al-O bond fracture is promoted. The fly ash provides active Al2O3 and SiO2 to promote the generation of C-(A)-S-H gel, so that the material has better mechanical properties. The desulfurized gypsum is used as sulfate solid waste, and Ca < 2 + > and SO4 < 2-> are provided to promote the formation of ettringite and fill internal pores. In addition, a small amount of admixture is used, the early strength of the material is remarkably improved through doping of cement, the doping amount of water is reduced through doping of a water reducing agent, the compactness of the material is improved, generation of microcracks is inhibited through the bridging effect of fibers, and the durability of the material is remarkably improved. The filling material provided by the invention is low in cost, good in compressive strength, strong in erosion resistance and excellent in environmental protection performance, and resource utilization and large-scale consumption of solid wastes such as red mud are favorably realized.

The invention relates to a portland cement product for negative temperature and application thereof, in particular to application of a negative temperature product containing portland cement clinker and an anti-freezing agent in preparation of a negative temperature product capable of maintaining mechanical properties under a negative temperature condition. According to the present invention, the negative temperature environment applicability is strong, the temperature range of the conventional winter construction can be reached, the rapid strength development rate can be maintained in the negative temperature environment, the hydration heat release peak is advanced by 2-3 h, the construction requirement without the external heat source can be met, the hydration product mainly comprises ettringite and C-S-H, and the foundation is established for the cement product strength. The adopted mixing solution not only can prevent freezing, but also can accelerate coagulation. On one hand, the anti-freezing agent is added into the water, so that the vapor pressure of the water is changed, and the freezing point of the solution is reduced; and on the other hand, the anti-freezing agent contains a component for promoting hydration of the sulfur silicate cement, so that the sulfur silicate cement can be rapidly hydrated under a negative temperature condition, and the purposes of rapid setting and hardening and strength improvement of a cement product are achieved.

The invention relates to the technical field of mortar concrete, in particular to a method for improving impact resistance by doping shear thickening fluid into mortar concrete, which comprises the following steps: dry-mixing cement and aggregate, adding water, stirring to prepare fresh mortar slurry, adding shear thickening fluid capsules into the fresh mortar slurry, and uniformly mixing and stirring; wherein the shear thickening liquid capsules are capsules filled with shear thickening liquid. By doping the shear thickening fluid capsule, an STF-based honeycomb network structure is generated in the mortar, the energy dissipation effect of the mortar is improved, meanwhile, nano SiO2 in the STF component can fill air gaps in the mortar, generation of hydration products (hydrated calcium silicate gel and ettringite crystals) is improved, compactness of a mortar matrix is promoted, and the strength of the mortar is improved. The compression resistance, the impact resistance and the like of the modified mortar material are obviously improved.

The invention provides a cement-based material for immobilizing a neutron activation material, and belongs to the technical field of immobilizing materials for treating radioactive nuclear waste, the cement-based material comprises 5-10 parts of boron nitride, 80-120 parts of a gel material, 50-80 parts of a boric acid solution, 8-20 parts of an additive, 0.2-3 parts of a nucleating agent, 0.5-2 parts of a water reducing agent and 0.5-3 parts of a foaming agent, the concentration of the boric acid solution is 3-6 mol / L, the additive comprises sodium hydroxide and sodium aluminate, and the foaming agent comprises sodium hydroxide and sodium aluminate. The nucleating agent comprises one or more of synthetic hydrated calcium silicate gel, layered double hydroxides and a carbon nanomaterial. The admixture and boric acid are jointly added into the gel material, sodium hydroxide in the admixture can adjust the occurrence state of borate, sodium aluminate can promote formation of hydration products such as ettringite, and therefore the content of boron and hydrogen in a cement solidified body is effectively increased, and the shielding capacity of the cement solidified body for neutron rays is improved.

The present invention provides a method and device for preventing calcium scale from forming on the surface of a waste sulfuric acid neutralization system. In the present invention, sodium sulfate and other soluble sulfates, lime emulsion to adjust the pH of the waste acid, and polyaluminum chloride solution are sequentially added to the effluent (waste acid) of the original first limestone neutralization process in the original waste acid treatment system. After the addition of the reagent, the effluent is still subjected to the second lime neutralization process according to the original process. 2+ 、SO4 2‑ The characteristic of easy formation of calcium sulfate is that it is regulated by chemical agents. The present invention only adds soluble sulfates such as sodium sulfate, regulates the pH of waste acid and uses polyaluminium chloride to directly reduce the Ca content in waste acid. 2+ concentration, while increasing SO4 in waste acid 2‑ The invention reduces the concentration of scale-forming components in the liquid phase of the waste acid by directly producing ettringite in the reaction tank. With only minor adjustments, this invention can prevent the formation of calcium scale on the surface of the waste sulfuric acid neutralization system and improve the operational stability of the waste acid treatment device.

The invention provides a reinforced ardealite aggregate, an ultra-high performance concrete material and a preparation method thereof, and belongs to the field of building materials. The preparation method of the reinforced ardealite aggregate comprises the following steps: mixing the ardealite, the cement, the primary aluminum ash, the water and the ettringite crystal form control agent to obtain a mixture; carrying out extrusion molding and autoclaved curing on the mixture to obtain phosphogypsum aggregate; the preparation method comprises the following steps: dipping ardealite aggregate in an organic silicon emulsion, and drying to obtain hydrophobic ardealite aggregate; and putting the hydrophobic ardealite aggregate into a strong alkali solution in which carbon dioxide is continuously introduced to react, and drying to obtain the ardealite composite material. The ardealite and the primary aluminum ash react to generate ettringite, and the ardealite and the carbon dioxide react in a strong alkali solution to generate calcite to synergistically improve the strength of the aggregate, so that the reinforced ardealite aggregate disclosed by the invention can be used for preparing an ultra-high performance concrete material with compressive strength higher than 150MPa; the problem of shortage of natural quartz sand resources is solved while ardealite resources and a large amount of accumulated primary aluminum ash resources are consumed.

The present application relates to the technical field of foam concrete preparation, in particular to foam concrete based on ettringite micro-expansion effect and a preparation method thereof, the preparation method comprising the following steps: S1. preparation of modified ettringite; S2. dry material premixing; S3. preparation of additives; S4. concrete forming. The modified ettringite and modified calcium sulfate synergize to significantly improve the interfacial bonding strength of aggregate-matrix, so that the early and medium-term compressive strength of the composite system is improved; at the same time, the improved pore structure forms a triple action mechanism of "ettringite reinforcement-pore optimization-stress buffering": ettringite improves the interfacial bonding and shrinkage compensation capacity, the dissolution space of aggregate absorbs the volume deformation stress, the pore structure optimization reduces the humidity diffusion gradient, and the strength-shrinkage synergistic control is realized.