284 results about "Mullite" patented technology

The invention belongs to the technical field of motor casing lost foam casting, and particularly relates to a special coating for a motor casing lost foam as well as a preparation method and application thereof. Through a quantitative formula design method, an aggregate proportion calculation formula based on thermal expansion coefficient matching and a grain size distribution correlation formula based on target air permeability, cooperative compounding of quartz powder and bauxite is achieved, and key functional components such as mullite, organic matter fibers and crystalline flake graphite are combined; the unification of high air permeability and excellent crack resistance of the motor shell lost foam coating is realized. The invention further provides a two-time coating gradient drying efficient process matched with the coating, and on the premise that the coating performance is guaranteed, the production efficiency is remarkably improved, and the energy consumption is reduced.

The invention relates to the technical field of special functional coating materials for lost foam casting, and particularly discloses a special coating for a large machine tool casting lost foam as well as application and a use method of the special coating. According to the invention, the full-temperature-range functional composite material and the composite aggregate are used for synergistic reinforcement, and mullite is used for high-temperature reinforcement; the temperature-sensitive polymer modified graphite can realize intelligent temperature response of graphite performance; spodumene is used as a thermal expansion adaptive fluxing agent, so that medium-temperature healing and thermal expansion adjustment of a coating system are facilitated; the composite reinforced fibers are reinforced and toughened aiming at large thermal stress of thick and large parts; as an ultralow-temperature glazing agent, the boron-containing glazing agent can form an initial liquid phase at about 450 DEG C to seal the surface of the coating and purify a ventilation channel; the rare earth oxide serving as a high-temperature phase stabilizer can be dissolved in mullite crystal lattices, so that the high-temperature phase stability is improved, and ceramic nodes are refined. Through raw material design, on the premise of ensuring moderate air permeability, the ultrahigh strength and crack resistance of a coating system at extremely high temperature are improved.

The invention belongs to the technical field of refractory materials, and particularly relates to a mullite refractory material with high mechanical property and a preparation method thereof. The mullite refractory material is prepared by taking coal gangue, bauxite and fly ash as raw materials, and the three industrial solid wastes are converted into the refractory material with high additional value, so that the concept of circular economy is met. According to the invention, coal gangue, bauxite and fly ash are used as raw materials, CaF2, V2O5 and lanthanide rare earth oxide are used as sintering aids, the problems of insufficient mechanical properties and overhigh sintering temperature of the mullite refractory material prepared by purely using coal gangue, bauxite and fly ash as raw materials are solved, and the performance of the mullite refractory material can be greatly improved. CaF2 and V2O5 promote substance transport and grain growth, and rare earth oxide inhibits excessive growth of grains. The balance of'promotion 'and'inhibition' is favorable for forming a compact, fine, uniform and interlaced mullite crystal network, and meanwhile, the mullite crystal network has high strength and good toughness.

The present application relates to the technical field of special functional coating materials for lost foam casting, and specifically discloses a special coating for large machine tool castings, and application and use method thereof. The present application synergistically strengthens full-temperature-range functional composite materials and composite aggregates, and uses mullite for high-temperature strengthening. Temperature-sensitive polymer modified graphite can realize intelligent temperature response of graphite performance. Lithium feldspar as a thermal expansion adaptive fluxing agent is more conducive to the medium-temperature healing and thermal expansion adjustment of the coating system. Composite reinforcing fibers are used to enhance and toughen the thick and large workpiece with large thermal stress. Boron-containing glazing agent as an ultralow-temperature glazing agent can form an initial liquid phase at about 450 DEG C, seal the surface of the coating, and purify the air passage. Rare earth oxides as high-temperature phase stabilizers can be solid-solved in the mullite lattice, improve the high-temperature phase stability, and refine the ceramic nodes. Through raw material design, the coating system has improved ultrahigh strength and crack resistance at extreme high temperatures under the premise of ensuring moderate air permeability.

The invention discloses a high-bending-resistance and low-dielectric-loss LTCC substrate preparation method and an LTCC substrate, and the method comprises the steps: mixing inorganic powder, an organic system and a solvent through ball milling, dissolving and stirring, and preparing a green ceramic chip through a tape casting technology; carrying out lamination, warm isostatic pressing, cutting, glue discharging and sintering on the green ceramic chip to obtain the LTCC substrate; the inorganic powder comprises sodium borosilicate glass, aluminum oxide and mullite whiskers. According to the invention, the sodium borosilicate glass is used as a glass phase, the mullite whisker and the alumina powder are used as ceramic phases, and the excellent mechanical properties and extremely low dielectric loss of the mullite whisker are utilized to modify the sodium borosilicate glass-alumina composite material. The problems that an existing sodium borosilicate glass-aluminum oxide LTCC composite material is low in bending strength and high in dielectric loss are solved.

The invention discloses a whisker-reinforced composite porous ceramic material as well as a preparation method and application thereof, which are based on a new process of combining silicon carbide and cordierite and are combined with factors such as silicon carbide particle size and sintering conditions to really realize effective combination of low thermal expansion characteristic of cordierite and high strength characteristic of silicon carbide. The invention aims to synchronously improve the thermal shock resistance and mechanical bearing capacity of a product so as to provide a DPF filter body material with better performance. Furthermore, in order to optimize the filtering performance, mullite whiskers grow in the composite matrix in situ, and a more efficient particulate matter trapping network is constructed, so that the mechanical reliability, the thermal stability and the filtering efficiency are synergistically improved.

The present application relates to bulk handling and transport equipment technical field, specifically is related to a kind of artificial synthetic mullite's loading equipment, including feed cylinder, driving arm, throwing material disc and material blocking assembly.The buffer flow passage in feed cylinder is used to reduce the impact of falling material;Driving arm is used to drive feed cylinder to displace in vertical and horizontal direction, facilitate to go into car hopper operation;Throwing material disc rotation is arranged below feed cylinder for centrifugal throwing material.Material blocking assembly is arranged below throwing material disc, including lifting base and two groups of symmetrical material blocking piece, and each group of material blocking piece contains telescopic arm and several flexible material blocking strips.Through lifting base and telescopic arm linkage, flexible material blocking strip forms two symmetrical barrier zones in the periphery of throwing material disc, for intercepting stone material thrown to the width direction of car hopper, prevent stone material from accumulating in the same area, while the empty area between barrier zone allows stone material to be normally thrown out.The present application is compact in structure, realizes the self-adapting uniform filling of car hopper, and reduces the material breakage rate.

The application discloses a ladle heat-insulating high-strength light-weight castable which is prepared from the following raw materials in percentage by mass: 45-60% of mullite hollow spheres, 5-10% of expanded perlite, 5-10% of polycrystalline mullite fiber, 5-10% of magnesium oxide fine powder, 1-5% of aluminum powder, 1-5% of binding clay, 2-8% of rho-Al2O3 micro powder, 1-5% of sodium lignosulfonate, and 1-4% of SiO2 micro powder. The castable provided by the application has high strength, low thermal conductivity and good thermal shock resistance, can be used for ladle permanent layer castable, can effectively reduce the temperature of a ladle shell, plays a ladle heat-insulating role, can reduce the temperature of molten steel when a converter is tapped, reduces energy consumption, and reduces the cost per ton of steel.

The mullite high-temperature hot patching material is prepared by mixing the electro-fused mullite, the bimodal alumina micro powder, the additive modified powder, the electro-fused mullite, the fast sintering agent, the clay, the coagulant and the sintering aid, carrying out hot-state patching construction operation by adopting an injection machine or a spray gun, and carrying out fast reaction and sintering in a hot state to obtain a compact refractory material. The refractoriness of the generated refractory material is greater than or equal to 1750 DEG C, the load softening point is greater than or equal to 1700 DEG C, and the refractory material can bear 1700 DEG C high-temperature

The invention relates to the technical field of metallurgical coking, and provides a devitrification and CO erosion resistant zero-expansion silica brick and a preparation method thereof.The devitrification and CO erosion resistant zero-expansion silica brick is prepared from, by weight, 3-10 parts of nanoscale alpha-Al2O3, 15-35 parts of andalusite, 30-40 parts of high-purity fused mullite, 10-20 parts of superfine silica powder, 2-5 parts of silica sol binding agent and 3-5 parts of composite mineralizer. Through the synergistic effect of the design of the composite mineralizer and the stepped heat treatment process, the technical problems that the existing zero-expansion silica brick is easy to devitrify and crystallize fused quartz, poor in CO erosion resistance and lack of crystallization degree during long-term use at high temperature are solved; the thermal shock cycle index and the high-temperature breaking strength of the material can be improved, the formation of alpha-cristobalite crystallization peak is effectively inhibited, and the mass loss is reduced in a reducing atmosphere, so that the structural stability of the material is enhanced, and the service life of the material is prolonged.

The invention discloses a method for preparing environment-friendly domestic porcelain from waste domestic porcelain, and relates to the technical field of domestic porcelain, and the environment-friendly domestic porcelain is prepared from the following components in parts by weight: 20-25 parts of recycled porcelain powder, 28-38 parts of kaolin, 12-17 parts of porcelain clay, 10-15 parts of quartz, 18-23 parts of albite and 0.2-0.5 part of maltodextrin. The preparation method comprises the following steps: preparing the waste domestic porcelain into recycled porcelain powder; mixing and ball-milling the recycled porcelain powder, kaolin, porcelain clay, quartz, albite and maltodextrin in parts by mass to obtain slurry; squeezing, sinking and pugging the mud to obtain strip mud; molding and glazing the strip clay; and sintering the glazed green body to obtain the environment-friendly domestic porcelain. According to the invention, the resource consumption and environmental pollution can be obviously reduced, the plasticity and molding stability of the pug can be improved, the uniform formation of a glass phase and a mullite crystal phase can be promoted through a specific component ratio and multi-stage sintering, and the qualified rate of finished products is high.

The invention relates to the technical field of coal gangue treatment, in particular to a method for preparing high-purity mullite through coal gangue pretreatment-calcination coupling. The high-purity mullite is prepared by the following steps: crushing, grinding and sieving, adding soluble salt, phosphoric acid and ammonium salt in an alkaline hydrothermal reaction, roasting and removing impurities, modifying by using a composite mineralizer, coating by using silicon-aluminum sol, carrying out suspended three-stage calcination and the like. The method solves the technical problems of insufficient activation of the coal gangue, difficulty in deep removal of impurities, low purity of mullite and low resource utilization efficiency of the coal gangue in the traditional process, and realizes efficient resource conversion of the coal gangue. Through the synergistic effect of all process links, the crystal phase purity and structural compactness of mullite are effectively improved, the obtained product has good application performance, a feasible path is provided for preparation of high-value mullite from coal gangue, and the method is suitable for the related fields of high-temperature structural materials and the like.

The application discloses an antioxidant composite ceramic aerogel and a preparation method thereof, and belongs to the technical field of composite ceramic aerogels.The main body of the antioxidant composite ceramic aerogel is a silicon nitride aerogel, the nanostructure of the silicon nitride aerogel is one of one-dimensional silicon nitride nanowires and two-dimensional silicon nitride nanobands or a combination of the two nanostructures, and a mullite coating and a copper-nickel metal coating are sequentially coated on the nanostructure of the silicon nitride aerogel from inside to outside.The application can solve the technical problem that the prior art cannot prepare silicon nitride ceramic aerogels which can stably serve in a high-temperature oxygen environment at low cost and in batches.

The invention discloses an electric furnace bottom blowing brick with a composite structure. The seat brick, the air brick and the Venturi gas distributor are sequentially arranged from bottom to top; a hollow channel communicated with the seating brick and the Venturi gas distributor is arranged in the air brick; wherein the air brick is a nano grain boundary reinforced magnesium aluminate spinel air brick and contains 5-8% of nano ZrO2 particles (the particle size is smaller than or equal to 50 nm), the porosity is 18-22%, and the average pore size is 25-45 microns; the seating brick is a gradient corundum-mullite seating brick, the inner layer of the seating brick comprises 90% of Al2O3, 8% of mullite and 2% of SiO2, the outer layer of the seating brick comprises 75% of Al2O3, 20% of mullite and 5% of an expanding agent, and the inner wall of the seating brick is provided with a honeycomb hexagonal groove array with the depth of 3-5 mm. By adopting the nano ZrO2 reinforced magnesium aluminate spinel material, the air brick can resist the temperature of more than or equal to 1600 DEG C, has the porosity of 18-22%, has both air permeability and erosion resistance, and prolongs the service life. When the gas flow fluctuation is larger than 5%, the flow velocity is automatically compensated to a set value + / -3% through the Venturi effect; the gas consumption is reduced.

The invention provides a preparation process of a high-performance refractory material based on regulation and control of a dolomite crystal form. The preparation process specifically comprises the following steps: step 1, weighing raw materials; step 2, pre-sintering the raw materials: respectively putting the weighed corundum, dolomite, quartz sand and mullite into a high-temperature furnace for high-temperature pre-sintering at the high-temperature pre-sintering temperature of 500-600 DEG C, heating and pre-sintering for 15-25 minutes, then taking out, and placing the pre-sintered corundum, dolomite, quartz sand and mullite clinker for later use; when the device is used, raw materials are pushed by the spiral auger to flow in the conveying holes from bottom to top, the thickness between the raw materials is reduced when the materials flow in the conveying holes, and the raw materials are matched with the heating columns on the inner walls of the conveying holes to achieve rapid temperature rising and heating; and the raw materials are pushed by the spiral auger to move upwards to the top of the fixed barrel to be stirred and mixed again.

The invention discloses a high-strength wear-resistant thermal-insulation refractory material for dry quenching and a preparation method thereof, and relates to the technical field of refractory materials, the high-strength wear-resistant thermal-insulation refractory material comprises the following raw materials by weight: 60-70 parts of silicon carbide, 0.5-1 part of ferric oxide, 10-15 parts of alumina, 5-7 parts of an auxiliary agent, and 8-12 parts of mullite powder. According to the refractory material for the dry quenching, by using a proper amount of the auxiliary agent and cooperating with the silicon carbide, the mullite powder, the ferric oxide and the aluminum oxide, the thermal insulation performance of the prepared refractory material for the dry quenching meets the use requirements, and meanwhile, the refractory material for the dry quenching is endowed with high normal-temperature compression strength, high-temperature breaking strength and wear resistance.

The invention relates to the technical field of refractory materials, in particular to a refractory precast block for a tunnel kiln car table top and a preparation method of the refractory precast block, and aims at achieving synergistic improvement of alkali corrosion resistance and thermal shock resistance under the working condition of coupling of alkali-rich steam and frequent thermal shock. According to the formula, white molten aluminum oxide, molten magnesium aluminate spinel, alpha-aluminum oxide, plate-shaped aluminum oxide, calcined kaolin and the like are used as aggregates and matrixes, zirconium phosphate grafted with double-molecular-weight methoxy polyethylene glycol silane is introduced to serve as a grading template and an interface coupling unit, and a low-temperature curing-medium-temperature calcining-permeating-high-temperature sintering technology is adopted, so that the high-performance magnesium aluminate spinel ceramic is prepared. A calcium hexaluminate / mullite / magnesium aluminate spinel / aluminum phosphate four-phase interpenetrating network and controlled composite pore structure is constructed in the material. The refractory precast block has high volume density and low vacuum porosity, the refractoriness reaches about 1790 DEG C, the strength retention rate is excellent after 10 times of alkali steam-thermal shock cycles, the size and quality changes are controlled, and the service life of a kiln car table top is remarkably prolonged.

The present application relates to the technical field of industrial solid waste utilization, and discloses a synthesis method of smelting fly ash-based mesoporous material, which uses smelting fly ash as a main raw material, uniformly mixes sodium carbonate and smelting fly ash at a specific ratio, and calcines at a suitable temperature, so as to destroy the difficult-to-dissolve glass phase and mullite phase in the smelting fly ash, make the smelting fly ash form a low-carbon cerchi stone phase which is easy to react with acid, and react with low-concentration hydrochloric acid, so as to prepare a mesoporous material with large specific surface area and pore volume and concentrated pore size distribution. The specific surface area of the best sample in the present application is 567.45 m2 / g, the pore volume is 0.95 cm3 / g, the most probable pore diameter is 18.30 nm, the Si / Al ratio is 3.65, and the yield is 44.59%. The preparation process of the method is simple, does not need to use expensive template agents, has high implementability and production safety in actual production, and realizes high-value utilization of smelting fly ash.

The invention discloses a solar molten salt furnace refractory brick capable of resisting thermal shock and a preparation method of the solar molten salt furnace refractory brick capable of resisting thermal shock and the preparation method of the solar molten salt furnace refractory brick. 3 to 5 percent of alpha-Al2O3 micro powder; 8 to 12% of kaolinite; 7-9% of high alumina bauxite; 4-6% of modified fluorite tailing ceramsite; 1-3% of a binding agent; 2.5-3% of refractory mortar; 5-10% of a regenerated bamboo fiber skeleton; mullite: the balance; the combined action of the modified fluorite tailing ceramsite and the regenerated bamboo fiber skeleton effectively improves the cold and heat shock resistance and high temperature molten salt erosion resistance of the brick body, and optimizes the performance of the brick body.

The invention discloses a mullite whisker modified toughening agent, a preparation method thereof and well cementation cement slurry containing the mullite whisker modified toughening agent, and belongs to the technical field of oil-gas field development well cementation materials, the mullite whisker modified toughening agent comprises the following components by weight: 10-20 parts of mullite whisker, 0.05-0.4 part of a surfactant, and 3-18 parts of nano silica. The mullite whisker modified toughening agent provided by the invention has a good application effect in well cementation cement slurry, the particle size of the toughening agent is close to that of oil well cement particles, and when set cement forms micro cracks, the advantages of smaller size, special three-dimensional needle-shaped structure and the like of the toughening agent can be utilized to improve the toughness of the cement slurry. The mechanical property of the set cement is improved through the strengthening effects of crack bridging, deflection, whisker pulling-out and the like.

The application relates to the technical field of refractory materials, and particularly discloses a hercynite-mullite solid solution raw material and a preparation method thereof. The preparation method of the hercynite-mullite solid solution raw material comprises the following steps: after low-grade high-iron bauxite is crushed and homogenized, the low-grade high-iron bauxite is subjected to a flotation desilication treatment; the ore slurry after the flotation is subjected to a magnetic separation and iron removal treatment, so that the content of Fe2O3 in the ore slurry is controlled to be below 9 wt%; a carbon source is introduced into the ore slurry after the magnetic separation and iron removal, the ore slurry is uniformly mixed, and then the ore slurry is subjected to drying, shaping and sintering in a carbon-embedded atmosphere, and the hercynite-mullite solid solution raw material is obtained. The application realizes high-value and high-quality utilization of the low-grade high-iron bauxite. Through the flotation desilication and magnetic separation and iron removal processes, the contents of SiO2 and Fe2O3 in the raw material are effectively controlled, the low-grade ore which is originally difficult to be directly utilized is converted into qualified refractory material raw material, and the resource utilization efficiency and economic value are greatly improved.

This invention provides a mullite ceramic with integrated heat absorption and storage based on coal gangue and its preparation method, belonging to the field of ceramic materials technology. Using coal gangue as raw material, this invention controls the molar ratio of Al2O3 and SiO2 in the mixture by adding an aluminum supplement to ensure complete reaction of SiO2, avoid the formation of residual quartz, and promote the full formation of mullite. A crystallization promoter can promote the formation and growth of mullite crystals. This invention sequentially melts, refines, and cools the mixture to form large, interlocking mullite crystals, giving the mullite matrix material high thermal conductivity. This invention obtains a mullite ceramic with integrated heat absorption and storage through functional doping and molding processes. The results of the examples show that the mullite ceramic prepared by this invention has an absorption rate of over 91%, a heat storage density (200~1000℃) of over 780 kJ / kg, and an average crushing strength of over 70 N / particle.

The invention particularly discloses a method for increasing the aluminum-silicon ratio through coal gangue anoxic roasting and application of the method, and relates to the technical field of solid waste resource utilization, and the method comprises the steps that coal gangue with the initial aluminum-silicon ratio being 0.8-1.0 is crushed; an assistant A and an assistant B are added into the coal gangue, and the assistant A is prepared by mixing vermiculite powder and a cetyltrimethylammonium bromide solution, performing ultrasonic treatment for 30 minutes, and then compounding and calcining with sodium bentonite; the assistant B is prepared by mixing a borax solution and a cerous nitrate solution, evaporating and crystallizing, drying and grinding; a double-helix conical mixer is adopted for mixing, and 0.5% of deionized water is sprayed; sealing the mixture, introducing nitrogen, and maintaining the residual oxygen content lt; the invention discloses an aluminum-rich material with the aluminum-silicon ratio of 3-5.5, the method comprises the following steps of: heating coal gangue to 400 DEG C at the temperature of 2% under normal pressure, preserving heat, roasting at the speed of 8 DEG C / min, cooling to 200 DEG C, performing coarse crushing and alkali dissolution, filtering, washing, drying and micronizing by jet milling to obtain the aluminum-rich material with the aluminum-silicon ratio of 3-5.5, the method can also be applied to preparation of mullite bricks, 4A molecular sieves and porous ceramic filter materials, the process is simple, the cost is low, and high-valued utilization of the coal gangue is realized.

The application relates to the technical field of ceramic substrates, and discloses a nickel-coated multilayer ceramic substrate and a preparation method thereof. The nickel-coated multilayer ceramic substrate comprises an alumina ceramic substrate and a nickel-coated layer arranged on at least one side of the alumina ceramic substrate; the alumina ceramic substrate comprises the following raw materials in parts by weight: 70-90 parts of alumina, 5-8 parts of a sintering aid, 80-100 parts of a solvent, 10-12 parts of a binder and 0.5-2 parts of a dispersing agent; and the sintering aid comprises corundum-mullite composite material and zirconia-silicon carbide composite material. The above technical scheme solves the problem of insufficient strength of the nickel-coated multilayer ceramic substrate in the related art.

The application discloses cordierite-based microcrystalline glass adhesive for corundum-mullite ceramic pipes and a preparation method and application thereof, and is characterized in that cordierite microcrystalline glass powder and high-temperature frit are used as main raw materials, the high-temperature frit has a specific chemical composition, and interface reaction of the cordierite microcrystalline and the high-temperature frit can occur in the heat treatment process of pipe bonding, so that anorthite, pyromorphite, diopside, calcium-magnesium olivine and zirconite are generated on the surface of cordierite grains and serve as a wrapping layer of the cordierite grains, the mismatch of the thermal expansion coefficients between the glass phase and the cordierite grains can be effectively reduced, the residual thermal stress of the interface between the cordierite grains and the glass phase is reduced, the adhesive has high shearing strength, good thermal shock resistance and high-temperature durability, and thus the problem that there is no corundum-mullite ceramic heat pipe adhesive in the prior art is solved. The raw materials of the application are obtained from natural minerals, the preparation cost is low, the application has a wide market, and is favorable for popularization and application.

The application discloses a ceramic roller rod and a preparation method thereof, and relates to the technical field of ceramic matrix composites.The ceramic roller rod comprises a core layer, a transition layer and a surface layer;the layered gradient structure of the core layer, the transition layer and the surface layer is designed, alumina-zirconia, alumina-mullite and silicon nitride-titanium boride composite ceramic matrices are selected for each layer, and special matrix-reinforcing phase combinations are formed by matching nano silicon carbide particles, boron nitride particles and graphene microsheets;meanwhile, a pretreatment process of separately ball-milling and screening raw materials of each layer is adopted, thus solving the problems of the existing roller rod, such as single matrix matching conventional reinforcing phase, no functional doping ratio and easy agglomeration of overall mixed raw materials, so that the matrix and the reinforcing phase of each layer form material synergy, and the different functional requirements of the core bearing, the intermediate layer connection and the outer surface wear resistance and high temperature resistance are met respectively, and precise adaptation of material performance and functions of each part of the roller rod is realized.

The invention relates to the technical field of fiberboards, and provides a high-strength inorganic fiberboard and a preparation method thereof. The high-strength inorganic fiberboard is prepared from the following raw material components: microfiber glass wool, polycrystalline mullite fibers, ceramic fibers and an adhesive, the adhesive is prepared from the following raw material components: silica sol, an anti-settling agent, a coupling agent, metal oxide, calcium sulfate whiskers and water; the calcium sulfate whisker is silicon dioxide coated calcium sulfate whisker, and / or the metal oxide is polyvinyl alcohol composite metal oxide. According to the technical scheme, the problem that the strength of the inorganic fiberboard is insufficient when silica sol is used as a binder in the prior art is solved.