32results about How to "Good performance at high temperature" patented technology

The invention relates to a magnesium-aluminum-zirconium composite spinel refractory material. The refractory material is prepared from the following raw materials in percentage by weight: 50 to 95 percent of high-purity magnesia of which the granularity is less than or equal to 5 millimeters, 5 to 25 percent of magnesia-aluminum spine of which the granularity is less than or equal to 4 millimeters, 1 to 25 percent of desilicated zirconium or zircon sand of which the granularity is less than or equal to 3 millimeters and 1 to 6 percent of bonding agent in the raw materials. The refractory material is suitable for high temperature zones of large and medium-sized cement kilns, has high service performance and long service life, can completely replace magnesium-chromium refractory material tobe applied to the high temperature zone of a cement kiln, avoids environmental pollution caused by a magnesium-chromium brick after being used, and has very good economic benefit and social benefit.

The invention discloses an aluminum/zinc composite ultralow-carbon alumina-magnesite carbon brick for a ladle lining. The aluminum/zinc composite ultralow-carbon alumina-magnesite carbon brick is made by the following steps of: mixing raw materials, aging, molding, carrying out heat treatment at 180-250 DEG C and curing for 16-36 hours. The aluminum/zinc composite ultralow-carbon alumina-magnesite carbon brick comprises the following raw materials in percentage by weight: 40-60% of magnesite granule, 5-15% of magnesia alumina spinel granule, 25-35% of magnesite fine powder, 3-8% of aluminum/zinc metallic composite powder, 0-1% of crystalline flake graphite, 0.5-2% of boracic antioxidant and 3-4% of organic bond. The volume density of the aluminum/zinc composite ultralow-carbon alumina-magnesite carbon brick is greater than or equal to 3.0g/cm<3>, the apparent porosity is not more than 5%, the cold compressive strength is not lower than 45 MPa, the carbon-embedded high-temperature folding strength at 1400 DEG C is not lower than 25MPa, the content of MgO is not less than 75%, and the carbon content is not more than 2%.

The invention discloses a long-service-life iron runner castable for hot repair. The long-service-life iron runner castable for hot repair comprises the following components in percentage by mass: 56%-64% of brown fused alumina, 5%-13% of silicon carbide, 2%-3% of ball pitch, 1.5%-2.5% of calcium aluminate cement, 8%-12% of alumina micro-powder, 1.5%-2.5% of silicon dioxide micro-powder, 11%-13% of silicon carbide powder, 1%-2% of a composite antioxidant, 0.1%-0.3% of metal aluminum powder, less than 0.1% of explosion-proof fibers, 0.2%-0.4% of a dispersing agent and 0.08% of a coagulant. Thenovel coagulant is used for the iron runner castable, thus, the metal aluminum powder in the iron runner castable produces hydrogen ahead of time, the gas is generated to open an exhaust hole when thecastable is not cured, then, the castable is matched with the suitable metal aluminum powder and the low-melting-point explosion-proof fibers, and it ensures that the castable has excellent high-temperature usability while meeting the condition of construction.

The invention relates to a composite interlayer and a method for brazing metal with a ceramic and ceramic matrix composite material by utilizing the same, and solves a difficult problem of poor connector performance caused by a large amount of brittle phases generated in a strong reaction of a connector interface during brazing of the metal and the ceramic and ceramic matrix composite material by adopting an active brazing material and large residual stress of the connector after welding. The composite interlayer comprises an upper-layer brazing material, a soft interlayer and a lower-layer brazing material. The method comprises the following steps: 1, brazing material preparation, wherein the brazing material is prepared at a certain ratio; 2, cleaning, wherein cleaning is performed by acetone; 3, assembling, wherein a to-be-welded base material and the composite interlayer are assembled according to a certain sequence; 4, welding, wherein welding is performed in a vacuum brazing furnace. The operation is simple, and the addition of the interlayer inhibits over-reaction of the brazing material and the base material, reduces residual stress of the connector, and greatly improves the connector performance. The method is used for brazing the metal with the ceramic and ceramic matrix composite material.

The invention relates to ramming mass for a medium-frequency induction furnace and a preparing method thereof. According to the technical scheme, 58-74 wt% of fused corundum, 6-18 wt% of tabular corundum, 8-16 wt% of fused magnesite, 2-9 wt% of alpha-Al2O3 micro powder, 1-3 wt% of aluminum lactate and 1-6 wt% of magnesium lactate are used as raw materials and mixed uniformly to obtain the ramming mass for the medium-frequency induction furnace, wherein the particle size of aluminum lactate and magnesium lactate is smaller than 0.18 mm, the particle size of fused corundum is 0.088-5 mm, and the content of Al2O3 of the fused corundum is 94-99.5 wt%; the particle size of tabular corundum is 0.044-1 mm, the particle size of the fused magnesite is 0.044-1 mm, and the content of MgO of fused magnesite is larger than or equal to 95 wt%; the raw materials are mixed in a mixer for 10-25 min. The preparing method has the advantages of being simple in process and environmentally friendly. The prepared ramming mass for the medium-frequency induction furnace is high in refractoriness, erosion resistance and scouring resistance and long in service life.

The invention belongs to the field of porous ceramic and in particular relates to an environment-friendly method for preparing mullite fiber based porous ceramic through gel casting. The mullite fiberbased porous ceramic is prepared from the following raw materials in percentage by mass: 11 to 32 percent of rho-Al2O3 powder, 13 to 36 percent of kaolin or zircon powder and 33 to 75 percent of mullite fiber. The method comprises the following steps: taking the rho-Al2O3 powder and the kaolin or zircon powder; adding a certain amount of de-ionized water; mechanically stirring and carrying out ultrasonic oscillation to obtain stable and uniform ceramic slurry; then uniformly adding the mullite fibers into the ceramic slurry; continually stirring and oscillating to obtain gel ceramic-fiber slurry; then carrying out injection molding and curing at room temperature; putting a molded biscuit into a constant-temperature drying box and drying; after de-molding, putting into a high-temperature furnace; sintering under an air atmosphere to obtain mullite combined or ZrO2-mullite combined mullite fiber based porous ceramic. The environment-friendly method has a simple and feasible technology and is environmentally friendly; the prepared mullite fiber based porous ceramic has high porosity, low heat conductivity and relatively high strength.

The invention relates to a sleeve lime kiln. A sleeve lime kiln empty-kiln baking method comprises the steps: introducing coal gas to temporary burners of the sleeve lime kiln; starting up an exhaust gas draught fan to allow a negative pressure in the kiln to be greater than or equal to -0.05 kPa; igniting the temporary burners in order, inserting ash discharging devices from ash discharging device observation holes, and making the burners upward and fixing; when the temperature in the kiln rises to 50 DEG C, controlling the temperature rising speed at 3 DEG C to 5 DEG C per hour for rising the temperature; when the temperature rises to 280 to 300 DEG C, carrying out heat preservation; 24 hours later after beginning to baking the kiln, opening burner drainage screws and exhaust gas flue drainage holes, after the burners drain, tightening the screws, and timing for every 4 hours to drain once; carrying out continuous heat preservation until drainage ports have no obvious water, that is to said moisture of a refractory material in the kiln is baked to a reasonable control range; cutting off temporary burner coal gas valves; closing the exhaust gas draught fan; and eight hours later, closing a cooling draught fan. The method can effectively remove the moisture in the refractory material and ensure the high-temperature using performance of the refractory material.

The invention discloses a low-heat-conductivity multilayer composite potassium aluminosilicate brick and a preparing method thereof.The low-heat-conductivity multilayer composite potassium aluminosilicate brick comprises a working layer, a heat preservation layer and a heat insulation layer, wherein the working layer and the heat preservation layer are connected into a whole in the length direction of the brick, a notch is formed in the end face, located in the width direction of the heat preservation layer, of the heat preservation layer, the shape of the heat insulation layer is matched with that of the notch, and the heat insulation layer is arranged in the notch.The working layer is prepared from synthesis potassium aluminate with the particle size ranging from 0 to 1 mm, silicon carbide with the particle size ranging from 1 mm to 3 mm, silicon carbide with the particle size ranging from 3 mm to 5 mm, synthesis potassium aluminate with the particle size smaller than 0.074 mm, silicon carbide with the particle size smaller than 0.074 mm, an antioxidant and a binding agent.The heat preservation layer is prepared from synthesis potassium aluminate with the particle size ranging from 0 to 1 mm, silicon carbide with the particle size ranging from 1 mm to 3 mm, silicon carbide with the particle size ranging from 3 mm to 5 mm, synthesis potassium aluminate with the particle size smaller than 0.074 mm, silicon carbide with the particle size smaller than 0.074 mm, a high-temperature reinforcing agent, a composite organic pore forming agent and a binding agent.The heat insulation layer is made of an aluminum oxide fiberboard.The low-heat-conductivity multilayer composite potassium aluminosilicate brick has excellent high-temperature usability by means of the advantages of the multilayer composite structure, and the heat conductivity coefficient and the body density are far lower than those of products of the same kind.

The invention discloses a magnesium-zirconium spinel ramming material for a furnace bottom. The ramming material is prepared from the following raw materials in parts by weight: 50-80 parts of high-grade magnesia, 10-35 parts of magnesium aluminate spinel, 2-8 parts of zirconium oxide and 7-15 parts of carbon-contained binding agent. The ramming material can be used for improving the filling condition of a triangle area part at the furnace bottom and providing a certain protection for a furnace shell in a high-temperature state, so that the furnace life is prolonged, and the working safety is favorably realized.

The invention discloses a silicon nitride-based ceramic welding sealing component and a preparation method thereof, and relates to the technical field of metallized ceramic processing. The invention discloses a silicon nitride-based ceramic welding sealing component which comprises a silicon nitride ceramic matrix and a metallization layer, the silicon nitride ceramic matrix is prepared from modified silicon nitride, mullite fiber, aluminum nitride, calcium oxide, titanium oxide, a binder and a dispersing agent through the steps of modified silicon nitride preparation, mixing, granulation, primary sintering, secondary sintering and the like; raw materials of the metallization layer comprise copper powder, tungsten powder, copper oxide, yttrium oxide, zinc oxide and an organic binding agent. The invention further discloses a preparation method of the silicon nitride-based ceramic welding sealing component composed of the metallization layer and the silicon nitride ceramic matrix. According to the silicon nitride-based ceramic welding sealing component, the density of the silicon nitride ceramic matrix is improved, the silicon nitride-based ceramic welding sealing component has excellent strength, hardness and fracture toughness, the tensile strength of the sealing component is improved, and the silicon nitride-based ceramic welding sealing component has excellent high-temperature resistance.

The invention relates to a silicon carbide-niobium brazing connection method, in particular to a method for improving the silicon carbide-niobium brazing connection quality through low-expansion 4J42 alloy interlayer auxiliary brazing filler metal. The method aims to solve the problems that residual stress of existing silicon carbide and niobium brazing connection is overlarge and the ceramic side interface reaction is poor. The method comprises the step 1 of pretreatment; and the step 2 of vacuum brazing. The method is used for improving the silicon carbide-niobium brazing connection quality through the low-expansion 4J42 alloy interlayer auxiliary brazing filler metal.

The invention relates to a low-heat-conductivity multi-layer composite magnesium-hercynite brick and a preparation process thereof. The low-heat-conductivity multi-layer composite magnesium-hercynite brick is prepared from the following raw materials in percentage by weight: 70-95% of microporous high-purity magnesia, 4-15% of hercynite, 2-10% of light forsterite, and 1-5% of a binding agent in a working layer, and 10-50% of microporous high-purity magnesia, 50-80%of light forsterite and 1-10% of nano aluminum oxide micro powder in a heat insulation layer. The heat insulation layer is a nano aerogel plate. According to the low-heat-conductivity multi-layer composite magnesium-hercynite brick and the preparation process thereof, the overall volume density is small, the heat conductivity coefficient is far lower than that of an existing product, the energy consumption of a thermotechnical kiln can be remarkably reduced, the purposes of saving energy and reducing consumption are achieved, and in the actual production process, production and preparation are convenient and efficient, so that actual application and popularization are facilitated, and therefore, the problems of high energy consumption and short service life of the existing cement kiln adopting pleonaste bricks are effectively solved.