14results about How to "Reduce internal porosity" patented technology

This invention belongs to the field of industrial solid waste resource utilization technology, and relates to a circulating fluidized bed ash-based cementitious material for road base courses and its preparation method. The raw materials for the road base course cementitious material are composed of the following mass parts: 29-43 parts of circulating fluidized bed ash, 16-27 parts of ground blast furnace slag, 3-6 parts of silica fume, 7-15 parts of P.O42.5 silicate cement, 0.1-0.4 parts of activator, and 27-30 parts of water. The circulating fluidized bed ash is prepared by mixing circulating fluidized bed fly ash and slag in a mass ratio of (2-5):(5-10). This invention effectively alleviates the problems of fast setting time and shrinkage cracking of traditional road base course cementitious materials by utilizing the characteristics of micro-expansion and long hydration time of circulating fluidized bed ash. The advantage of this invention is that it promotes the large-scale utilization of circulating fluidized bed ash and contributes to carbon emission reduction in the road sector.

The invention relates to the technical field of spacecraft skins, in particular to a lightweight thermoplastic composite material film for a spacecraft skin. The thermoplastic composite material film is prepared by the following steps: dipping carbon fibers and a hollow ceramic tube in a mixed solution consisting of polyetherimide and graphene oxide dissolved in N-methyl pyrrolidone, and then carrying out heat treatment to obtain modified carbon fibers and modified hollow ceramic tubes; adding polyarylene ether nitrile into a double-screw extruder, melting, adding the modified hollow ceramic tube, and continuously mixing for 10-15 minutes to obtain a resin matrix; the preparation method comprises the following steps: mixing modified carbon fibers with a resin matrix, casting the mixed material to form a film, cooling to room temperature, rolling to obtain unidirectional prepregs, crosswise and symmetrically laying the unidirectional prepregs, and carrying out hot press molding to obtain the lightweight thermoplastic composite film for the spacecraft skin. The film prepared by the invention has the effects of low density, high strength and extreme climate resistance.

The invention discloses a high-strength plant cellulose-based composite paperboard and a preparation method thereof, belongs to the technical field of paperboard materials, and aims to solve the technical problem that the strength and wet strength retention rate of a plant fiber-based composite paperboard in the prior art need to be further improved. The composite plant fiber layer is composed of a plant fiber layer and interface layers arranged on the two sides of the plant fiber layer in a modifying mode. A plant fiber layer is prepared through CMC modified plant cellulose, a PEG modified inorganic reinforcing agent and a bio-based toughening agent reinforced plant fiber, a composite structure of an interface layer, a fiber layer and an interface layer is formed by arranging a double-interface layer containing lignin nano particles / carboxylated nano cellulose, and a hot-pressing curing process is combined, so that the lignin / carboxylated nano cellulose composite fiber is prepared. The strength and toughness of the plant fiber-based composite paperboard are effectively improved, and the wet strength retention rate of the material is also effectively improved.

The invention relates to the technical field of preparation of foam glass, in particular to high-strength and low-heat-conductivity foam glass and a preparation method thereof. The problems that existing foam glass is low in strength and high in heat conductivity are solved. According to the foam glass, waste glass and glass fibers are used as raw materials, silicon carbide is used as a foaming agent, borax is used as a fluxing agent, trisodium phosphate dodecahydrate is used as a foam stabilizer, modified polyurethane and silicon dioxide aerogel are used for modifying the foam glass, the porous structure advantage of the aerogel enables heat to be transmitted along a slender framework of the aerogel, the heat transfer flux is low, and the foam glass has good heat transfer performance. The heat loss in the transmission path is large, and due to the existence of the aerogel particles, the solid-phase transmission path of heat in the foam glass is more complex, the CF3 group low surface energy reduces the heat convection path and inhibits the solid-phase heat conduction, so that the foam glass has a lower heat conductivity coefficient, and the mechanical strength of the material is improved. Therefore, the durability and thermal insulation performance of the foam glass are enhanced.

The invention provides full-phosphogypsum-based concrete and a composition and mix proportion design method thereof. The method comprises the following steps: S10, determining material composition: adopting sulphoaluminate cement fired by phosphogypsum as a sole cementing material, directly adopting phosphogypsum particles as aggregate, and directly adopting undisturbed phosphogypsum as a retarder; and S20, performing mix proportion design based on the composition materials, including S21, grading optimization design for specific aggregate: performing grading optimization design on phosphogypsum particles by adopting a corrected Andriasen model based on a close packing theory to obtain a close aggregate packing state, and S22, performing grading optimization design on the phosphogypsum particles by adopting a modified Andriasen model based on the close packing theory to obtain the close aggregate packing state. And S22, slurry-to-bone ratio design based on the compact aggregate accumulation state: based on an excess slurry theory, calculating the total slurry volume percentage according to the real void percentage of the phosphogypsum particles and the additional slurry volume percentage required for aggregate separation, and finally determining the slurry-to-bone ratio. The technical problems of existing concrete in the aspects of cementing materials, aggregates, retarders and performance optimization are solved.

This application relates to the field of monolithic refractory materials, specifically disclosing a self-flowing, densified, cement-free refractory castable and its preparation process. The self-flowing, densified, cement-free refractory castable includes aggregates, binders, admixtures, a modified water-reducing agent, and water. The preparation method of the modified water-reducing agent includes the following steps: adding an aqueous solution of methacryloyloxyethyl phosphate, methoxy polyethylene glycol acrylate, acrylic acid, methacryloyloxypropyltrimethoxysilane, and mercaptoacetic acid to water to obtain solution A; adding ammonium persulfate and ammonium bisulfite to water and mixing thoroughly to obtain solution B; adding water to a reaction vessel, heating, and simultaneously adding solutions A and B dropwise to the reaction vessel; after the addition is complete, maintaining the temperature to continue the reaction, cooling, and adjusting the pH with triethanolamine to obtain the modified water-reducing agent. The refractory castable in this application has excellent self-flowing molding, a highly dense structure, and high-temperature resistance and slag corrosion resistance.

This invention provides a mixed aggregate mine backfill material of ultra-fine iron tailings sand and steel slag sand and its preparation method, belonging to the field of building materials. The mixed aggregate mine backfill material of ultra-fine iron tailings sand and steel slag sand provided by this invention comprises the following components in parts by weight: 6-13 parts iron tailings powder, 9-20 parts slag powder, 0.5-1 part desulfurization ash, 20-38 parts ultra-fine iron tailings sand, 10-28 parts steel slag sand, 0.6-1.4 parts activator, and 25-41 parts water. The mixed aggregate mine backfill material of ultra-fine iron tailings sand and steel slag sand provided by this invention has a 120-day shrinkage rate as low as 2.12% and a 28-day compressive strength as high as 7.68 MPa, exhibiting low shrinkage and high compressive strength.

The application relates to the technical field of plastic processing equipment, and discloses an environment-friendly plastic granulator for plastic processing, which comprises a bottom box, a treatment barrel for dehumidifying and processing recycled plastics is arranged at the top of the bottom box, a granulation main machine box is arranged on one side of the treatment barrel, and the recycled plastics after multiple treatments in the treatment barrel are subjected to granulation processing treatment; and a preliminary treatment mechanism is used for preliminarily dehumidifying and processing the recycled plastic raw materials after a cleaning process. By increasing and arranging an auxiliary treatment mechanism, the mechanism can not only replace the wet steam in the material pores by dry nitrogen during the pulse drying process, strengthen the removal effect of the internal pore water of thick-wall materials, and improve the defect that the outside is dry and the inside is wet in the traditional drying process, but also remove the combined water in the intermolecular gap of the melt by the nitrogen gas stripping effect during the melt granulation stage, further reduce the hydrolysis reaction probability in the melt state, and reduce the internal bubble defects of the melt.

The invention belongs to the technical field of water pollution control and treatment, particularly relates to a sludge treatment device, and aims to solve the problems that existing sludge treatment equipment is poor in dewatering-anti-blocking collaboration, poor in treatment parameter pertinence, low in heat energy recovery efficiency, poor in forming effect and insufficient in equipment integration degree. Two supporting plates are fixedly mounted at the top of the bottom plate, the conveying and feeding mechanism is arranged on the two supporting plates and comprises a conveying cylinder, and a plugging cover is arranged at an opening of the conveying cylinder. Through the collaborative design of three-stage variable-pitch screw extrusion dewatering, memory metal filter screen heating anti-blocking, sludge component real-time detection, dosing, stirring and conditioning, extrusion shaping and drying integration and precise waste heat recovery and preheating, the problems that existing equipment is low in dewatering efficiency, prone to blockage, high in energy consumption and poor in forming effect are solved; the efficient, energy-saving and stable treatment of the sludge is realized.

The invention belongs to the technical field of gel materials, and mainly provides rapid-reinforcing early-strength repairing type mortar and a preparation method thereof.The preparation method comprises the following steps that metering and even mixing are conducted, specifically, rapid-hardening sulphoaluminate cement, Portland cement and fly ash are weighed and evenly premixed, and a gelling component A is obtained; weighing steel slag and quartz sand, and uniformly mixing to obtain an aggregate component B; weighing a water reducing agent, an early strength agent, a retarder and half of the total weight of water, and uniformly mixing to obtain an admixture component C; stirring: adding the aggregate component B and water accounting for 1 / 4 of the total weight, rapidly mixing and stirring, adding the gelling component A, continuously stirring, adding the additive component C and water accounting for 1 / 4 of the total weight, and continuously stirring, so as to prepare the rapidly-reinforced early-strength repair mortar. And molding and curing. The uniformity is improved through grouping premixing, the interface bonding performance is improved through staged stirring, the defects of insufficient early strength caused by uneven components, poor interface, slow hydration and the like in traditional preparation are overcome, and the early strength advantage is fully exerted.

This invention relates to the field of repair materials technology, and discloses a binary composite fiber-reinforced epoxy resin-based rapid repair material and its preparation method, comprising the following raw materials in the indicated mass ratios: 259.85g epoxy resin, 89.36g curing agent, 25.99g diluent, 24.22g toughening agent, 1200g fine aggregate, 259.85g filler, 1.04g defoamer, 0.78-2.34g basalt fiber, and 15.59-31.18g calcium sulfate whiskers. In this invention, the large-scale basalt fiber and the small-scale calcium sulfate whiskers are mixed and incorporated into the binary composite fiber-reinforced epoxy resin-based rapid repair material and its preparation method. The abundant freely distributed fibers can constrain the propagation of microcracks of different sizes and regions within the repair material matrix, effectively improving the shortcomings of conventional epoxy resin-based repair materials, such as poor early performance, high brittleness, and insufficient toughness, achieving a balance between high early strength and high toughness in the epoxy resin-based repair material.

The application provides a high-purity silicon carbide structural member and a preparation method and application thereof. The preparation method comprises the following steps: preparing slurry by mixing beta-phase silicon carbide powder with a first particle size and beta-phase silicon carbide powder with a second particle size according to a weight ratio of 10:1-2, wherein the purity of the beta-phase silicon carbide powder with the first particle size is greater than or equal to 99.999%, and the purity of the beta-phase silicon carbide powder with the second particle size is greater than or equal to 99.999%, and the first particle size is greater than the second particle size; ball-milling the slurry, performing suction filtration, and drying to obtain mixed powder; dry-pressing the mixed powder into a blank; cold isostatic pressing the blank to obtain a blank; performing hot isostatic pressing sintering on the blank to obtain a silicon carbide ceramic member; and performing post-processing on the silicon carbide ceramic member to obtain the high-purity silicon carbide structural member. The technical problem to be solved is how to prepare a high-purity silicon carbide structural member, so that the high-purity silicon carbide structural member can simultaneously have high purity and high density, the production efficiency is improved, the manufacturing cost is reduced, and the high-purity silicon carbide structural member is easier to be mass-produced, thereby being more suitable for practical use.

The application relates to the technical field of high polymer composite materials, and discloses a carbon fiber reinforced polyether ether ketone composite material, a preparation method thereof and an elevator hub, wherein the composite material is mainly made of polyether ether ketone, polyether imide, diphenyl sulfone and pre-coated carbon fiber. The pre-coated carbon fiber is attached with a B-stage solid-state boron-modified thermoplastic phenolic resin on the surface, and when the pre-coated carbon fiber is heated during extrusion, the resin is converted into a C-stage network, topological-level physical entanglement occurs between the resin and the macromolecular chain segments of the matrix, and a semi-interpenetrating polymer network structure is formed in situ at the interface. When the composite material is prepared, the flash phase change of the diphenyl sulfone under specific temperature and pressure generates micro-bubbles, and the micro-bubbles carry water molecules released by interface polycondensation and discharge the high-viscosity melt. The application improves the interface bonding state between the carbon fiber and the matrix, reduces the micro-porosity of the composite material, improves the mechanical strength and the fatigue resistance of the material, and can be used for injection molding of structural parts such as large-load elevator hubs.

This invention discloses a high-strength niobium-molybdenum alloy and its preparation method. The alloy, by atomic percentage, comprises: 13-31% molybdenum, 5-9% zirconium, and at least two elements selected from titanium, chromium, vanadium, and aluminum, with the balance being niobium and unavoidable impurities. The preparation method includes: firstly, weighing high-purity metal particle raw materials according to the designed proportions; employing vacuum induction suspension melting technology, fully melting the raw materials under vacuum conditions ≤5×10⁻³Pa and melting temperature 1800-2400℃; and obtaining a pre-alloy ingot through 3-5 inverted melting processes; subsequently, wrapping the pre-alloy ingot with tantalum foil and performing hot isostatic pressing densification treatment under high-purity argon protection at a pressure of 220-250 MPa and a temperature of 1300-1500℃ to obtain the high-strength niobium-molybdenum alloy. The alloy has a density of ≤8.8 g / cm³, a room temperature strength of ≥663 MPa, a 1000℃ strength of ≥397 MPa, and a 1600℃ strength of ≥127 MPa. Its comprehensive mechanical properties reach or exceed those of commercial C-3009 alloy. At the same time, it replaces expensive elements such as Hf and W with low-cost elements such as Mo and Zr, which significantly reduces the material cost.