78results about How to "Improve high temperature flexural strength" patented technology

The present invention relates to a kind of high crystal structure cordierite-mullite kiln furniture, kiln furnace refractory product and roasting process. Its raw material includes (by weight portion) 50-80 portions of main crystal phase material and 20-50 portions of combined compound matrix material, in the above-mentioned raw material a proper quantity of crystal nucleus formation agent can be added. Its roasting process includes two stages of high-temperature constant-temperature microcrystallization nucleation intensification treatment. Said invention also provides the concrete steps of every stage.

The invention discloses a nanometer material contained ladle bottom argon blowing permeable brick and a preparation process thereof. The permeable brick comprises components of high-purity corundum, spinel, alpha-Al2O3 micro powders, nano calcium carbonate, Si powders, binding agents and antiknock agents. The preparation process of the nanometer material contained ladle bottom argon blowing permeable brick includes the following steps of dosing, fine powder premixing, stirring, vibration forming, curing with molds, demolding, drying and baking. According to the nanometer material contained ladle bottom argon blowing permeable brick and the preparation process thereof, Cr2O3 is not used, and during usage, new pollutants are not generated, so that pollution treatment costs are reduced, and high environmental benefits are achieved; micropores are evenly distributed in the brick, so that cracks are effectively prevented from continuing spreading during usage, the toughness of the permeable brick is improved, the spalling is reduced, the service life of the permeable brick is prolonged, the permeable brick is basically free from bonding slag after usage, cleaning during usage is reduced, and production costs of iron and steel enterprises are reduced.

The invention relates to an in-situ synthesized mullite whisker reinforced high-temperature ceramic roller which is prepared from natural raw mineral materials and industrial raw chemical materials. The in-situ synthesized mullite whisker reinforced high-temperature ceramic roller comprises the following compositions in percentage by weight: 15-25% of kaolin, 5-15% of refractory clay, 15-25% of alpha-Al2O3 micro-powder, 3-10% of zirconium silicate, 10-20% of zirconium-titanium mineralizer containing andalusite and 30-40% of refractory corundum; and the ceramic roller is prepared through the following steps: ball-milling, stirring, molding, drying, roasting at a temperature of 1500-1600 DEG C, carrying out heat preservation for 5-10 hours, and naturally cooling, thus obtaining a ceramic roller product (the rupture strength of the product is greater than 57.40 Mpa at a temperature of 1350 DEG C). The in-situ synthesized mullite whisker reinforced high-temperature ceramic roller provided by the invention has a wide application prospect in roasting roller kilns for products such as high-temperature and high-load domestic ceramics, building sanitary ceramics, high-grade large-sized vitrified tiles, technical ceramics and magnetic materials and the like.

The invention relates to a high-crystal mullite-iolite high-temperature industrial ceramic and a production method for the same. Raw materials comprise, by weight, 40-80 parts of main crystal phase materials, 20-60 parts of combined composite substrate materials and an appropriate amount of composite microcrystal nucleating agent. A roasting process of the production method includes a two-stage constant-temperature roasting method and a two-stage composite crystallization synthetic reaction characteristic enhancing process, wherein the two-stage constant-temperature roasting method includes the steps of performing constant-temperature heat preservation for 10-15 hours at the temperature of 200 DEG C, and performing constant-temperature heat preservation for 10-15 hours at the temperature of 500 DEG C; and the two-stage composite crystallization synthetic reaction characteristic enhancing process includes the steps of sintering for 10-15 hours under the ordinary pressure and at the temperature ranging from 1100 DEG C to 1150 DEG C, and sintering for 20-25 hours under the ordinary pressure and at the temperature ranging from 1420 DEG C to 1430 DEG C. A refractory product produced bythe method has the advantages of excellent oxidation resistance, high refractoriness, high usage temperature, low thermal expansion coefficient, high compression strength, hypobarism, excellent heat stability, anti-strip performance and high high-temperature bending strength. The process of the method has the advantages of simple process, low cost and suitability for mass production, and is applicable to preparing kiln furniture, industrial ceramics and structural materials.

The invention belongs to the field of refractory matters for ferrous metallurgy and in particular relates to an Al2O3-SiC-C refractory brick for a torpedo ladle produced by utilizing a waste Al2O3-C material and a preparation method of the Al2O3-SiC-C refractory brick. The Al2O3-SiC-C refractory brick comprises the following raw materials in percentage by weight: 10-40% of special grade bauxite clinker particles with the particle size of 3-5mm, 10-30% of special grade bauxite clinker particles with the particle size of 1-3mm, 5-20% of alundum particles with the particle size of 0.088-1mm, 5-20% of corundum fine powder with the particle size of less than 0.088mm, 2-8% of silicon carbon particulates with the particle size of 0.088-1mm, 2-8% of silicon carbon fine powder with the particle size of less than 0.088mm, 10-25% of waste Al2O3-C material fine powder with the particle size of less than 0.088mm, 5-15% of alumina micro powder with the particle size of less than 0.088mm, 3-10% of binding clay fine powder with the particle size of less than 0.088mm, 1-10% of crystalline flake graphite powder with the particle size of less than 0.088mm, 0.5-5% of asphalt powder with the particle size of less than 0.088mm, and 4-8% of additional phenolic resin.

The present invention relates to a stress-buffering refractory material that is used for dry quenching coke equipment, and belongs to the refractory material. The stress-buffering refractory material is prepared by mixing stress-buffering raw materials, waste kiln, sintered or electrically molten mullite, micro Al2O3 powder, clay and dextrin water; wherein, the stress-buffering raw materials is molded through extrusion after andalusite, fused silica, the micro Al2O3 powder and the clay are mixed well, and is prepared after high-temperature sintering at temperature between 1400 DEG C and 1650 DEG C; the refractory material can buffer the stress produced by sudden cooling and sudden heating when in use; the thermal shock stability, high-temperature rupture strength, wear resistance and service life are greatly improved. Compared with the existing refractory material that is used for the dry quenching coke equipment, the thermal shock resistance is improved by 20 to 40 percent; the mechanical properties are improved by 10 to 20 percent; the erosion resistance is improved by 30 to 50 percent; the wear resistance is improved by 15 to 35 percent and the service life is improved by more than 50 percent.

The invention relates to a slide plate refractory with silicon nitride added and a production method thereof. The slide plate is prepared by the following raw materials in percentage by weight: 45-65% of corundum, 10-25% of zirconia-mullite and/or zirconia-corundum, 2-8% of silicon nitride, 6-18% of alumina fine powder and the balance one or more of silicon metal, carbon black and graphite powder and a phenolic resin binder accounting for 4-6% of the total above raw materials. The production method is characterized by proportionally weighing the raw materials, uniformly mixing the raw materials, obtaining the mixture through mixing, press-forming the mixture, drying the formed mixture at 190-210 DEG C for 6-10h and then carrying out nitridation firing on the dried mixture at1200-1400 DEG C. The invention has the following benefits: by adding silicon nitride and reasonably adding other components according to the amount and ratios, the slide plate composite material with structure of Al2O3-ZrO2-Si3N4-C is formed, and the oxidation resistance of the slide plate is improved; and the apparent porosity of the refractory is 1-4%, the cold compression strength is 150-220MPa, the high temperature rupture strength is 28-33MPa and such performance indexes as the oxidation resistance, the scouring resistance, the thermal shock resistance and the like are all excellent or good.

The invention relates to a MgO-Cr7C3 brick for a ladle slag line and a production method of the MgO-Cr7C3 brick. According to the technical scheme, the production method includes: using 55-65wt% of high-purity magnesia particles as the aggregate and 15-25wt% of fused magnesia fine powder, 10-15wt% of Cr7C3 fine powder and 5-10wt% of SiC fine powder as the matrix materials; according to the contents of the aggregate and the matrix materials, evenly mixing the matrix materials first, adding the evenly-mixed matrix materials into the aggregate, and evenly mixing; adding alumina sol accounting for 3-7wt% of the sum of the aggregate and the matrix materials, mixing for 5-10 minutes, and using a semi-dry method to perform mechanical pressing; placing the formed blank into a high-temperature furnace, sintering at 1500-1600 DEG C and under the argon atmosphere, and keeping the temperature for 2-3 hours to obtain the MgO-Cr7C3 brick for the ladle slag line. The production method has the advantages that the method is simple in process, and the produced MgO-Cr7C3 brick is high in compactness, large in high-temperature bending strength, high in slag erosion resistance and low in pollution to molten steel.

The invention relates to a mullite aluminum nitride prefabricated brick formed by nitriding sintering. The mullite aluminum nitride prefabricated brick is prepared by the following steps of: adding an additive into mullite, aluminium nitride, silicon metal, aluminium metal, silica powder and aluminate cement serving as basic raw materials; uniformly mixing various raw materials and dispersing agents in a dried mode by using a stirring machine; adding water into the uniformly-mixed materials and stirring uniformly; injecting the mixed materials into a mould to be molded to form a prefabricated piece; roasting the prefabricated piece which is demoulded and naturally cured into a roasting kiln to roast; and finally putting the prefabricated piece into a high-temperature nitriding kiln at the high temperature of 1400-1500 DEG C under a nitrogen atmosphere to sinter; and after sintering the prefabricated piece, and cooling to the room temperature to obtain the prefabricated brick. Compared with the traditional product, the heat-state intensity of product disclosed by the invention is obviously improved and whole performance of the product disclosed by the invention is good.

The invention relates to a corundum-spinel refractory brick and a preparation method thereof. The corundum-spinel refractory brick comprises 55 to 60% by weight of brown fused alumina particles as aggregates, 20 to 25% by weight of aluminum-magnesium spinel fine powder as a base material, 15 to 20% by weight of caustic calcined magnesite powder as a base material, 1 to 2% by weight of aluminum powder as a base material and 1 to 4% by weight of iron powder as a base material. The preparation method comprises uniformly mixing the base materials, adding the aggregates into the base materials, mixing the mixture for 5 to 8 minutes, adding 3 to 6 wt% of thermosetting phenolic resin into the base materials and aggregates, mixing the mixture for 10 to 15 minutes, carrying out mechanical pressing molding, carrying out maintenance at a temperature of 200-250 DEG C for 12 to 18 hours, putting the molded material into a muffle furnace, carrying out heating to 1500-1600 DEG C under nitrogen atmosphere conditions, carrying out thermal insulation for 2 to 3 hours, and carrying out furnace cooling to obtain the corundum-spinel refractory brick. The preparation method has the characteristics of low cost and simple processes. The corundum-spinel refractory brick has high sintered density, large high temperature flexural strength and strong anti-slag erosion resistance.

The invention discloses a thermal-shock-resistant magnesian sliding plate brick which is prepared from the following raw materials in percentage by weight: 55-70% of modified magnesia particles, 30-45% of magnesia fine powder and 3-5% of paper pulp waste liquid. The preparation method comprises the following steps: firstly, preparing alpha-Al2O3 micro-powder coated modified magnesia particles by taking a saturated solution of aluminum chloride or aluminum sulfate as a binding agent, weighing the components according to the weight, mixing for 0.5 hour, forming by selecting a press machine according to the single weight of a sliding plate, drying a green body for 24 hours at the temperature of 110 DEG C, loading into a kiln, firing at 1500 DEG C for 8 hours, hooping the fired green body, adhering a steel shell, grinding, coating, finishing, checking and accepting, and storing in a warehouse. According to the thermal-shock-resistant magnesium sliding plate produced by the invention, low-expansion spinel is generated around magnesia particles to absorb thermal expansion of the magnesia particles, so that the internal thermal stress of the material is reduced and the thermal shock resistance is improved, through modification, the surface activity of magnesia particles is improved, sintering is promoted, combination of the particles and a matrix is strengthened, and the high-temperature strength is improved, so that the service life of the magnesian skateboard is prolonged and the sintering temperature is reduced.

The invention discloses a joint refractory material for heat exchange of the converter bottom and a preparation method and a construction method of the joint refractory material. The joint refractorymaterial is prepared from a first constituent part and a second constituent part, wherein the first constituent part comprises following components in percentage by weight: 63wt%-85wt% of magnesia, 0-10wt% of asphalt, 0-10wt% of graphite and 2wt%-17wt% of metal powder; the second constituent part is prepared from resin accounting for 5wt%-15wt% of weight of the first constituent part, alcohol substances accounting for 5wt%-15wt% of weight of the first constituent part and a curing agent accounting for 0.5wt%-1.5wt% of weight of the first constituent part. The joint refractory material can meetthe requirement of 1000-2000 furnaces of service life when the converter bottom is replaced in new furnace campaign and medium term of furnace campaign and guarantees normal and safe production of aconverter.

The invention relates to a submersed nozzle for steel making and continuous casting tundish, in particular to a non-oxide enhanced material for a slag line of a submersed nozzle. The material comprises the components in percentage by mass as follows: 5.5%-8% of ZrB2, 75%-78% of m-ZrO2, 6%-8% of graphite, 2%-3% of Al, 5%-6.5% of O'-Sialon, 1.0%-2.0% of Y2O3-PSZ and the balance of impurities; and 8-10% of a modified resin binding agent is additionally added. The non-oxide enhanced material for the slag line of the submersed nozzle has excellent corrosion resistance and plugging resistance, can effectively reduce carbureting of molten steel, and is more suitable for producing low -carbon steel and ultra-low carbon steel.

The invention belongs to the technical field of refractories for steel smelting furnaces, and in particular relates to a zirconium composite high-performance electrofused magnesium-calcium zirconium brick and a manufacturing method thereof; the zirconium composite high-performance electrofused magnesium-calcium zirconium brick comprises 5-10% of electrofused magnesium-calcium zirconium sand with a partical size of 5-8mm, 20-35% of electrofused magnesium-calcium zirconium sand with a partical size of 2-5mm, 20-30% of electrofused magnesium-calcium zirconium sand with a partical size of 2-0.074mm, 10-15% of electrofused magnesium-calcium zirconium sand fine powder with a partical size of 0.074mm or less, 1-5% of electrofused magnesium sand with a partical size of 5-8mm, 1-10% of electrofused magnesium sand with a partical size of 2-5mm, 1-5% of electrofused magnesium sand with a partical size of 2-0.074mm, 5-10% of electrofused magnesium sand fine powder with a partical size of 0.074mm or less, 5-10% of electrofused magnesium sand super-fine powder with a partical size of 0.037mm or less, 0.5-1.2% of calcium stabilized zirconia with a partical size of 0.5mm or less, 0.5-2% of metal calcium powder with a partical size of 0.088mm or less, 0.1-0.5% of silica fume with a partical size of 0.003mm or less and 2-5% of a binder. The method can obviously improve the physical and chemical performance indexes of the magnesium-calcium zirconium brick, anti-penetration, anti-erosion, anti-erosion and anti-spalling and other use performances of the magnesium-calcium zirconium brick can be improved, and most importantly, the magnesium-calcium zirconium brick can meet the requirements of current smelting conditions.

The invention relates to a multifiber reinforced magnesia-alumina-carbon refractory material and a preparation process thereof. A refractory brick is prepared from the following raw materials in percentages by weight: 8 to 10% of A-grade dead-burnt magnesia fine powder, 5 to 7% of B-grade dead-burnt magnesia fine powder, 19 to 22% of C-grade dead-burnt magnesia fine powder, 11 to 13% of D-grade dead-burnt magnesia fine powder, 8 to 10% of E-grade dead-burnt magnesia fine powder, 15 to 18% of F-grade dead-burnt magnesia fine powder, 7 to 8% of a binder A, 5.5 to 7.5% of a binder B, 1.3 to 1.7% of a binder C, 6 to 8% of metal aluminum powder and 0.3 to 0.5% of an additive. According to the invention, products and raw materials are safe and non-toxic, and may not cause harmful effects to users and the environment; good physical properties and wide application prospects in the fields of metallurgy and steelmaking are realized; the refractory material is improved in mechanical properties of the substrate thereof by mixed application of dead-burnt magnesia fine powder with different particles sizes, and is superior to a substrate material prepared from the dead-burnt magnesia fine powder with single particle size; the fiber structure greatly improves the mechanical properties of the material; meanwhile, carbon is difficult to be diffused into molten steel after carbon nanotube fiber is formed, so the pollution of the refractory materials to the molten steel is greatly reduced.

The invention relates to a high temperature nanometer non-burning slide plate and a processing technique thereof. By applying a method for shaping for many times, namely, a primary shaped slide plate is prepared firstly, and then slide plates in line of dimension requirement are shaped through gradually expanding outwards for several times on this basis; the slide plate is integrated structure. By applying the method of shaping for many times and the progressive way, the slide plate is more compactly pressed, and the primary shaping dimension is big; thus the primary shaped slide plate is not easy to deform and damage even through being pressed during the secondary shaping; meanwhile, the slide plate is provided with a reinforcing pipe to provide stress load during the pressing process, thus the shaping quality of the slide plate is further guaranteed; meanwhile, the reinforcing pipe is further arranged to be a hollow pipe, thus the reinforcing pipe can play a certain bearing effect during the secondary shaping and the third shaping; the reinforcing pipe also can be deformed and compactly inlaid in the groove for being pressed, thus the shaping quality and compact consistence of the slide plate are guaranteed.

The invention relates to an aluminum oxide-silicon carbide-carbonaceous cement-free castable suitable for construction in winter. The technical scheme is as follows: the castable comprises the following components in percentage by weight: 58-62wt% of dense corundum particles; 6-10 wt% of silicon carbide particles; 2-3 wt% of spherical asphalt; 4-10 wt% of alumina micro powder; 4 to 5 wt% of silicon dioxide micro powder; 7-10 wt% of silicon carbide powder; 1 to 1.5 wt% of silicon powder; 0.1-0.15 wt% of polyacrylic acid; 6-9 wt% of dense corundum fine powder; 0.04-0.1 wt% of water-soluble fibers; and 0.2-0.3 wt% of caustic-burned magnesia powder. During construction, when the environment temperature and the water temperature are both lower than 15 DEG C, after construction is completed, a pouring body is cured at 33-38 DEG C until the pouring body is completely cured. The concrete has the advantages of being small in water adding amount, short in setting time and high in construction site safety, is good in compactness, free of cement, high in thermal strength and good in various technical indexes, and particularly completely meets the requirements of construction in winter.

The invention relates to a low-carbon magnesia carbon brick and a preparation method thereof. The technical scheme is as follows: 78-93 wt% of magnesia particles, 0.1-2 wt% of organic additives and 5-20 wt% of absolute ethyl alcohol are placed in a stirrer, stirred for 2-6 hours at a rotating speed of 300-600 rpm, dried at 80-110 deg c for 12-24 hours, and sieved to obtain pretreated magnesia particles with a particle size of 1-5 mm. Then, 63-75 wt% of the pretreated magnesia particles, 20-32 wt% of magnesia fine powder, 2-5 wt% of flake graphite, 1-3 wt% of an antioxidant and 2-5 wt% of thermosetting phenolic resin are used as raw materials to be uniformly mixed, pressed and molded at 150-200 MPa, and then cured at 180-240 deg c for 18-24 hours to prepare the low-carbon magnesia carbon brick. The invention has the characteristics of low production cost, simple process and easy industrial production, and the prepared low-carbon magnesia carbon brick has high thermal shock stability, high high-temperature bending strength and good slag erosion resistance.

The invention relates to a chromium-free magnesium composite brick used for a VOD furnace and a preparation method thereof. The preparation method comprises the following steps: firstly sintering macrocrystalline magnesium sand with yttrium oxide and dicalcium silicate at the temperature of about 1550 DEG C, firstly preparing a pre-prepared material with excellent high temperature mechanical properties by adopting a presintering method, taking the pre-prepared materials in different grain gradations as an aggregate of a mending material, also adopting electrically smelted zirconia and calcined alumina as additives to make an unfired chromium-free magnesium composite brick for replacing an existing fired magnesium chromium brick to be used, pollution of the magnesium chromium brick to the environment is avoided, and thermal shock resistance and high temperature bending strength of a refractory material used for the VOD furnace are improved, so that the service life of the VOD furnace is guaranteed.