246results about How to "Low apparent porosity" patented technology

The invention discloses an air brick used for a magnesium and carbon ladle, and a producing method thereof, aiming at producing high-quality air bricks used for the ladles. The mass percentage of the chemical compositions of the air brick is: 55 to 99 percent of MgO, 0 to 20 percent of C, 0 to 20 percent of AI2O3, 0 to 5 percent of ZrO2, 0 to 5 percent of AI, 0 to 5 percent of AI-Mg alloy, 0 to 5 percent of CaB6, and 0 to 2 percent of B4; the physical property indexes are: volume density (g/cm<3>): 3.00 to 3.15, apparent porosity (%): 1.5 to 5.0, cold compressive strength (MPa): 40 to 65, and distortion resistance at high temperature (MPa): 14.0 to 25.0. Raw materials adopted by the invention comprise fused magnesite, magnesite clinker, crystalline flake graphite, corundum, zirconia and oxidation inhibitor. The raw materials are added into a pug mill and externally added with a bonding agent for mulling. Mulled pug is added into a mould, and molded by utilizing isopressing equipment or a friction brick press or a hydraulic press. The invention obviously reduces the apparent porosity of the air brick, not only can improve the basic slag corrosion resistant capability of the air brick, but also can reduce the cost of the raw materials by more than two thirds.

The invention belongs to the technical field of refractory materials, in particular to an aluminum chrome refractory material, which takes white fused corundum as a body and is formed by adding scraps (the scraps are collected and crushed into the synthetic size) generated in the cold processing process of a dense chromic oxide product, Alpha-Al2O3 powder or chrome oxide green or white fused corundum powder and sintering at a high temperature in combination with an inorganic binding agent or an organic binding agent. A product obtained in the invention can be widely applied to a coal water slurry gasification furnace back lining, a hard carbon black reaction furnace inner lining, a residual oil gasification furnace inner lining in the petrochemical industry, a glass wool molten pool inner lining and the like, fully and effectively makes use of the scraps generated in the cold processing process of the dense chromic oxide product and has the characteristics of low impurity content, high refractoriness, excellent physical performance, good thermal shock resistance and strong erosion resistance.

The invention relates to a micro closed-cell light-weight corundum refractory aggregate and a preparation method thereof. The technical scheme is as follows: the preparation method comprises the following steps: by using 45-65 wt% of gamma-Al2O3 fine powder, 30-50 wt% of alpha-Al2O3 micropowder and 1-10 wt% of nano aluminum oxide micropowder as raw materials, adding water accounting for 40-80 wt% of the raw materials, and carrying out wet milling with a planet ball mill for 0.5-3 hours; putting the slurry subjected to wet milling in a mold, standing at room temperature for 12-24 hours, and stripping; and drying at 110-200 DEG C for 12-36 hours, and keeping the temperature at 1750-1900 DEG C for 1-8 hours to obtain the micro closed-cell light-weight corundum refractory aggregate. The micro closed-cell light-weight corundum refractory aggregate has the characteristics of low apparent porosity, high closed porosity, low volume density, small average pore size, lower heat conductivity and high molten slag erosion resistance.

The invention relates to an aluminum-magnesium lightweight refractory material and a preparation method thereof. The technical scheme comprises the following steps of: taking 60-85wt% of microporous corundum particles as an aggregate, taking 5-30wt% of fine corundum powder, and taking 2-10% of magnesium oxide micropowder and 4-9wt% of alpha-alumina micropowder as matrix materials; adding the matrix materials into the aggregate, additionally adding an adhesive which is 3-10wt% of the sum of the aggregate and the matrix materials, stirring uniformly and then mixing and milling for 15-30 minutes by a mixing mill, and molding by a brick pressing machine; and thermally processing the molded green body for 12-24 hours at 100-220 DEG C to obtain the aluminum-magnesium lightweight refractory material. The product prepared by the preparation method has the characteristics of small volume density, low apparent porosity, small average aperture, high refractoriness, large high-temperature strength, low thermal conductivity, good thermal shock resistance and strong capability resistant against the corrosion of media such as steel slag; and the prepared product is applicable to a working lining of a high-temperature industrial furnace.

The invention relates to a lightweight aluminum-magnesium castable and a preparation method of the lightweight aluminum-magnesium castable. The technical scheme is as follows: using 60-85wt% of microporous corundum granules as an aggregate, and using 5-30wt% of fine corundum powder, 2-10wt% of magnesium oxide micropowder and 4-9wt% of alpha-aluminum micropowder as matrix materials; premixing a polycarboxylate-type water reducer and the matrix materials firstly, wherein the polycarboxylate-type water reducer is 0.05-0.3wt% of the sum of the aggregate and the matrix materials; adding the premixed matrix materials into the aggregate; and then additionally adding a binding agent which is 3-10wt% of the sum of the aggregate and the matrix materials, and stirring uniformly to obtain the lightweight aluminum-magnesium castable. The lightweight aluminum-magnesium castable prepared by the method has the characteristics of small volume density, low apparent porosity, large high-temperature strength, good volume stability, low thermal conductivity and strong capability of resisting the corrosion of media such as steel slag; and the prepared lightweight aluminum-magnesium castable is applied to a working lining of a high-temperature industrial furnace, the energy consumption can be reduced, and the service life is long.

The invention discloses a silica brick for a glass furnace, and belongs to the technical field of refractory materials. The silica brick for a glass furnace comprises: by weight, 30 to 45% of silica having particle sizes of 3 to 1.0mm, 5 to 25% of silica having particle sizes of 1.0 to 0.5mm, 30 to 50% of silica having particle sizes less than 0.5mm, an additive and a composite additive, wherein the weight of the additive is 5 to 15% of the total weight of the silica and the weight of the composite additive is 2 to 10% of the total weight of the silica. SiO2 content of the silica is great than or equal to 99%. Al2O3 content of the silica is less than or equal to 0.25%. Fe2O3 content of the silica is less than or equal to 0.45%. The additive is a waste silica material having SiO2 content great than or equal to 96%. The composite additive is a mixture of lime milk, mill scales and calcium lignosulphonate. The silica brick for a glass furnace has high SiO2 content, a high yield, low impurity content, low apparent porosity, good high-temperature performances and a long service life. A preparation technology of the silica brick for a glass furnace is simple and is suitable for large-scale production.

The invention relates to lightweight micro closed cell magnesium-containing corundum refractory aggregate and a preparation method of the refractory aggregate. The method comprises the steps of taking 80-95wt% of gamma-Al2O3 fine powder, 1-10wt% of nano alumina powder and 1-10wt% of magnesium oxide micropowder as raw materials, adding water accounting for 40-70wt% of the raw materials, mixing, wet-milling with a planet ball mill for 0.5-3h to form slurry, putting the slurry in a mold, placing under a room temperature condition for 12-24h, removing the mold, drying a demolded green body for 12-36h at 110-200 DEG C, and carrying out heat preservation for 1-8h at 1750-1900 DEG C to form the lightweight micro closed cell magnesium-containing corundum refractory aggregate. The prepared lightweight micro closed cell magnesium-containing corundum refractory aggregate has the characteristics of low apparent porosity, high closed porosity, lower volume density, small mean pore size, lower heat conductivity, and strong washout and slag erosion resistance.

The invention discloses an unfired magnesia-alumina spinel brick. The unfired magnesia-alumina spinel brick comprises the following chemical components by mass: 80 to 90% of fused magnesia, 5 to 15% of magnesium-rich magnesia-alumina spinel, 1 to 3% of micro alumina powder, 1 to 3% of aluminum-silicon alloy powder and 0.2 to 0.6% of B4C. The chemical components are bonded together by using 3.5 to 5 wt% of an added binder. The content of magnesium oxide in the fused magnesia is greater than 98 wt%, and the content of magnesium oxide in the magnesium-rich magnesia-alumina spinel is greater than 30 wt%. The unfired magnesia-alumina spinel brick provided by the invention has excellent slag reaction resistance, slag penetration resistance, anti-stripping performance, anti-scouring performance, resistance to oxidation and a long service life, does not include the harmful element--chromium, avoids pollution and harm to human beings and the environment, needs low production cost and has a wide application scope.

The invention relates to a reworked material working lining of a continuous casting tundish and a preparation method for the reworked material working lining. The reworked material working lining is divided into an impact zone working lining and a non-impact zone working lining, which are internally attached to a permanent lining; the non-impact zone working lining sequentially comprises a ladle edge working lining, a ladle wall working lining and a ladle bottom working lining from top to bottom; the impact zone working lining is built by adopting waste magnesia-carbon bricks and regenerated coating material mud through a wet process; the ladle wall working lining and the ladle bottom working lining are built by adopting a regenerated dry material; an overflow port working lining and the lade edge working lining are built by adopting the regenerated coating material; a space between the two sides of a turbulent flow controller and the ladle wall permanent lining is filled by waste; and a regenerated coating material layer coats the outer surfaces of the waste magnesia-carbon bricks, the outer surface of the waste and the upper surface of the turbulent flow controller. By applying the reworked material working lining, the service life of a shaped blank continuous casting tundish reaches 33-38 hours, and refractory material cost of the regenerated material working lining is reduced by more than 60% year on year.

The invention discloses a special type composite low alumina mullite brick which is prepared by raw materials by weight percent: 10-30% of mullite with granularity of 3-1mm, 20-40% of flint clay with granularity of 3-1mm, 10-20% of flint clay with granularity of 1-0mm, 5-15% of flint clay with granularity of -200 meshes, 10-30% of sillimanite or andalusite, and 15-25% of additive. The materials weighed according to the mixture ratio are mixed and ground, processed by ageing, extruded to be molded, dried and finally sintered, so that the special type composite low alumina mullite brick can be obtained. The special type composite low alumina mullite brick has the advantages of low apparent porosity and impurity, high strength and refractoriness under load, micro-expanded product, high mullite phase and the like, and has the function of one brick for multiple purposes. The application of the special type composite low alumina mullite brick can save a great deal of maintenance costs and energy conservation cost for steel users, thus having remarkable social and economic benefits.

The invention relates to porous corundum aggregate with a core-shell structure and a preparation method thereof. The technical scheme comprises that the preparation method comprises: uniformly stirring 100 parts by mass of industrial aluminium oxide fine powder, 0.5-2.5 parts by mass of a foaming agent, 5-20 parts by mass of aluminum dihydrogen phosphate and 5-35 parts by mass of water, so as to prepare foam mud; firstly putting 100-200 parts by mass of industrial aluminium oxide fine powder into a sugarcoating machine, then putting the foam mud into the sugarcoating machine, performing wet-process pelletizing, naturally drying, and baking at 100-120 DEG C for 12-24 h; and then heating to 1600-1850 DEG C, and keeping warm for 1-3 h, so as to obtain the porous corundum aggregate with the core-shell structure. The production technology is simple, and the prepared porous corundum aggregate with the core-shell structure is low in apparent porosity, high in strength, good in thermal-shock stability and wide in application scope.

The invention relates to an anti-thermal shock iolite fireproof kiln furniture and a preparation method thereof. The fireproof kiln furniture comprises the raw materials of 25-37% of a matrix, 50-56% of an aggregate, 4-5% of a sintering agent and 9-14% of a fiber reinforced material, wherein the matrix is composed for 15-25% of kyanite fine powder, 15-25% of kaolin fine powder, 48-69% of and alusite fine powder, and 1-2% of magnesia fine powder, and the aggregate is composed for 60-75% of gangue and 25-40% of high bauxitic clay clinker. In the prepared fireproof material, acicular iolite and cylindrical mullite are interlaced to a net state, the particles are in a free state with uniform size, the matrix and the particles have a certain buffer area, a certain stress is absorbed, and crack dynamic expansion is avoided. An iolite-mullite multiphase is generated in the fireproof product, synchronous increase of flexural intensity and compression strength can be satisfied, and the heat stability of the final product is increased.

The invention discloses an automatic preparation method of a SiCf/SiC composite material flame tube. The preparation method comprises the following steps: preparing an interface layer from SiC fibersby adopting chemical vapor deposition, so as to obtain SiC fibers with a continuous interface layer; performing unidirectional tape laying and filament winding on the SiC fibers with the continuous interface layer according to the fiber volume and fiber orientation obtained by simulation calculation, so as to obtain net size forming preform; performing densifying treatment on the obtained preformby adopting a reactive melt infiltration process and the chemical vapor deposition process; preparing an environmental barrier coating on the surface of the obtained preform; finally, continuously preparing a thermal barrier coating on the surface, thereby fully intelligently obtaining the high-density SiCf/SiC composite material flame tube. The SiCf/SiC composite material flame tube prepared withthe method disclosed by the invention has the characteristics of high temperature resistance and long service life and also has the advantages such as low thermal expansion coefficient, high thermalconductivity, high thermal shock resistance and excellent mechanical property. Meanwhile, the preparation method is high in degree of automation, short in production cycle, low in cost and controllable in quality.

The invention provides a low-porosity periclase-magnesium aluminate spinel-zirconia sintered composite refractory material, which is prepared from the following materials: 35-48% of 5-1mm magnesia, 15-30% of 1-0.088mm magnesia or synthetic magnesium aluminate spinel, 10-30% of less than 0.088mm synthetic magnesium aluminate spinel, 0-12% of less than 0.020mm synthetic magnesium aluminate spinel, 0-10% of G alumina micro powder, 0-4% of magnesium oxide micro-powder, 1-10% of zirconium oxide micro-powder, 0.05-0.2% of external third generation water reducing agent and 3-7% of external sulfite lye. During production, the magnesia is taken as an aggregate, and the composite magnesium aluminate spinel-zirconium oxide is taken as a base material; in the base material, the synthetic magnesium aluminate spinel is taken as coarse particles, while in-situ spinel-zirconium oxide is taken as fine particles; a brick-making material is dispersed in an efficient dispersant and then formed into compact green bricks under high pressure; then the compact green bricks are sintered at high temperature to form the refractory material with a compact structure; according to the proportions of the raw materials, all the raw materials are weighed, blended, mixed, molded and dried, and then sintered in the temperature range from 1650 to 1800 DEG C for 5-10 hours, and finally, the refractory materials is obtained. The refractory material has extremely low apparent porosity, and excellent high-temperature resistance, thermal shock resistance and erosion resistance; therefore, the refractory material is applicable for the grid of the heat accumulating chamber of a glass kiln as an erosion-resistant refractory material.

The invention relates to a microporous light-weight corundum fireproof aggregate and a preparation method thereof. According to a technical scheme in the invention, 55 to 100 wt% of industrial alumina fine powder and 0 to 45 wt% of industrial aluminum hydroxide fine powder or alpha-Al2O3 micro powder are used as raw materials, and the raw materials undergo dry grinding on a ball mill for 0.5 to 3 h at first, then balling in a ball forming mill to obtain a ball blank with a size of 20 to 30 mm and finally rapid sintering in a shaft kiln at a temperature of 1700 to 1950 DEG C so as to obtain the microporous light-weight corundum fireproof aggregate. The preparation method for the microporous light-weight corundum fireproof aggregate is simple and easy and is applicable to volume industrial production; the microporous light-weight corundum fireproof aggregate has the advantages of a small bore diameter, high strength, low thermal conductivity, anti-scouring performance, erosion resistance and the like, can be used in a part where the wall of a steel ladle directly contacts with molten steel, is also applicable to production of iron runners, slide plates, ventilating bricks and the like and to other industrial kilns used in petrochemistry, ceramics and the like and can obviously reduce energy consumption.

The invention relates to an ultrahigh strength thermal shock resistance corundum/mullite product and a manufacture method thereof. The manufacture method comprises steps of stirring 8-mesh white corundum, 80-mesh white corundum, 320-mesh tabular corundum, 24-mesh capacitance synthetic mullite, 36-mesh capacitance synthetic mullite, 280-mesh andalusite, 180-mesh sillimanite, 800-mesh aluminum oxide powder, 200-mesh kaolin and yellow dextrin for 1-3 hours, then adding 8% water so as to wring, stacking and ageing for 10 days, stirring for 15 minutes again, then molding through jolt-squeeze, naturally drying in shade, then firing for 6-8 hours at 1600 DEG C-1620 DEG C so as to obtain the ultrahigh strength thermal shock resistance corundum/mullite product. According to the manufacture method, the raw material chemical components and granularity ratio are optimized, the product is sintered fully, and the prepared corundum/mullite product has low porosity, large volume density, good strength, good thermal shock resistance, good integrated quality, and long service life up to 4-6 months.

The invention relates to a method for improving technical characteristics of magnesia refractory materials which comprises, placing the magnesia refractory materials into a vacuum plant, vacuum-pumping to -0.05~-0.1MPa, pressure maintaining 1-15 minutes, pumping in chromium-containing precursor nano collosol under vacuum state, pressurizing to 0.1-0.5 MPa, pressure maintaining 1-15 minutes, releasing pressure, taking out magnesia refractory materials, baking and drying 10-72 hours at 100-200 deg. C.

The invention discloses a method for producing a direct-bonded magnesia-chrome brick with high refractorinees under load and high stability of thermal shock resistance, which comprises the following steps: (1) selecting 7.5 parts by weight of magnesite, 2.5 parts by weight of chrome ore and 0.5 part by weight of chromium refined powder; (2) mixing the materials evenly, putting into an edge runner mixer, adding a lignin solution with the weight 4-5% of the weight of the total material and putting into a pressing machine with the pressure greater than 630KN for molding after milling wetly to prepare a semi-finished product; and (3) after putting the semi-finished product into a dryer and drying, entering a tunnel kiln, sintering at the temperature of 1750+/-10 DEG C and keeping the temperature for 10-12 hours under the condition of the temperature of 1750+/-10 DEG C so as to obtain a finished product of a brick body. The brick body has high refractoriness under load, large volume density, low apparent porosity and high stability of thermal shock resistance, sets up the record of the longest use period of 456 days, replaces imported products in many large-sized cement enterprises successfully and breaks the current situation that fireproof materials used for the burning zone of a large-sized rotary cement kiln with a novel dry method generally depend on import.

The invention discloses a preparation method of a high temperature resistant forsterite type refractory material. The method comprises the following steps: using nickel-iron slag as raw materials and magnesia powder as additives, wherein the ratio of [w (MgO) + w (FeO)] to [w (Al2O3)+w (Cr2O3)] is 10.50 to 13.57, the ratio of w (MgO) to w (Cr2O3) is 34.90 to 48.12 and the ratio of w (MgO) to w (SiO2) is 1.19 to 1.61, adding binding agents and controlling calcination temperature to be 1360 DEG C to 1450 DEG C, inducing mineral phase reconstruction of the nickel-iron slag, optimizing transformation process of refractory crystal form (Mg2SiO4, MgO.Fe2O3, MgO.Al2O3, MgO.Cr2O3) to increase refractoriness of the refractory material. The refractoriness of the obtained refractory material is 1700 to 1800 DEG C, and the refractory material also has the advantages of high compressive strength, large bulk density, low apparent porosity, and can fully meet the industrial need of the refractory material. The preparation method of the high temperature resistant forsterite type refractory material has the advantages of high utilization rate of resources, high production efficiency, high added value, environment friendliness, easiness in process control, low production cost and the like.