107 results about "Hercynite" patented technology

The present invention mainly is characterized by that it uses the magnesium chloride solution obtained by utilizing old bitter or magnesite through a refining process and industrial ammonia water or ammonia gas as raw material, or utilizes magnesium sulfate solution and industrial ammonia water or ammonia gas as raw material. Ultragravity (rotaryl filled bed) technology is adopted and utilizes liquid-liquid phase reaction or gas-liquid phase reaction mode is utilized to prepare nanometer magnesium hydroxide fire-retardant material. Said invention solves the defects of traditional process, such as complex process, high cost, non-uniform grain size and difficult control, etc.

The invention relates to a synthesis method of hercynite and has the technical proposal that aluminium compound and iron compound are mixed according to the mol ratio of Al ion to Fe ion of two to one, added with TiO2 fine powder of 1-20wt percent of the mixture obtained from the mixing of the aluminium compound and the iron compound and 1-6wt percent of binding agent to be mixed for 5 to 180 minutes for formation and then dried for 20 to 30 hours under the temperature of 90 to 120 DEG C and warmed up to 1100 to 1700DEG C with a temperature rising speed of 0.5 to 10 DEG C/min in the atmosphere of nitrogen to be kept warm for 5 to 600 minutes and next naturally cooled so as to obtain the hercynite. The invention is characterized by simple technology, low reaction temperature, low cost of raw materials and no environmental pollution; due to the low oxygen content in the atmosphere of the nitrogen, Fe elements exist in the form of Fe<2+> and all aluminium and iron are transformed to FeAl2O4 under the firing temperature; in addition, as the TiO2 is introduced, Ti<4+> can easily enter into crystal lattice of the FeAl2O4 to produce oxygen-iron vacancy concentration and ferric-ion vacancy concentration so as to promote the sintering with apparent porosity less than or equal to 2 percent after sintering.

The invention relates to a magnesia-hercynite brick and a preparation method thereof, belonging to the technical field of refractory materials. The magnesia-hercynite brick comprises the following chemical components in weight percent: 2.5 to 9.6% of Fe2O3, 2.9 to 12% of Al2O3 and 76-93% of MgO, the main crystalline phase displayed by XRD spectrum line is FeO.Al2O3. The preparation method comprises the steps of additionally adding a binding agent, carrying out compression moulding, drying, and baking at high temperature to obtain the magnesia-hercynite brick, which is simple and practicable. The magnesia-hercynite brick can be applied to the fields suitable to high temperature, in particular to clinkering zones of a novel rotary kiln utilizing a dry line method, thus solving the problem of Cr6 + pollution caused by the use of magnesite-chrome bricks in clinkering zones.

The invention belongs to the technical field of preparation of materials and particularly relates to a method for synthesizing hercynite. Ferric oxide powder, aluminium metal powder and activated aluminium oxide powder are taken as raw materials and are synthesized into hercynite in a vacuum furnace through a solid-state sintering method, reduction is carried out on ferric oxide by metallic aluminium to generate aluminum oxide and metallic iron, excessive ferric oxide and metallic iron react to generate ferrous oxide, and finally ferrous oxide, generated aluminum oxide and added activated aluminium oxide react to generate hercynite. The method has the characteristics that the generation condition of the ferrous oxide is met through the reduction action of metallic aluminium on ferric oxide, a weak reducing atmosphere does not need to be controlled, and purified hercynite can be sintered in a vacuum condition, so that the rigorous requirement that the weak reducing atmosphere needs to be controlled when ferric oxide and aluminum oxide, serving as the raw materials, are sintered is avoided, and the technology is easy to control; and at the same time, large amount of heat radiated from the reduction reaction of ferric oxide by metallic aluminium can provide partial energy required by reaction, thereby reducing energy consumption.

The invention discloses a preparation method for a rebonded electrically fused chrome corundum brick. Corundum granules, chrome ore powder and chromic oxide powder are first prepared, electrically fused chrome corundum granules are synthesized according to a certain proportion, the materials are weighed according to 40 to 70 parts of corundum material, 8 to 20 parts of chrome ore material, 15 to 30 parts of synthesized electrically fused chrome corundum material and 1 to 3 parts of chromic oxide material, put into a mixing mill, added with aluminium dihydrogen phosphate solution, mixed, milled and pressed to form a semifinished green brick, and after drying and sintering, the finished product is prepared. The rebonded electrically fused chrome corundum brick has the characteristics of high refractoriness, high strength, high thermal shock resistance and strong corrosion resistance; because high-melting point chromohercynite and hercynite can be produced on the surface of a furnace liner and stuck on the furnace liner to form a protective layer, thus not only can the scouring resistance of the furnace liner be enhance, but also melt can be stopped from infiltrating the brick, and thereby the service life of the brick can be greatly prolonged.

The invention discloses a carbon-free ladle brick and a preparation method thereof. The carbon-free ladle brick is prepared by using bauxite chamotte, a corundum raw material, magnesium oxide and alumina micro powder as main raw materials, adding iron oxide, a magnesium chloride solution, sodium hexametaphosphate and canary dextrin, mixing the above-mentioned materials by using special procedures, storing an obtained mixed for 30 min, carrying out compression molding and drying the mixture at a temperature of 200 DEG C for 24 h. According to the invention, iron oxide and alumina micro powder are enabled to exist in gaps between aggregate and powder and form hercynite with a low thermal expansion coefficient at a medium-high temperature, and no excess iron oxide enters into a matrix, which enables the ladle brick to have good high temperature stability and anti-stripping performance; therefore, the problem that molten steel carburetting caused by high temperature melting loss of a refractory brick influences smelting quality is overcome, and the prepared carbon-free ladle brick has excellent performances of high strength, washing resistance, a long service life, etc.

The invention relates to a fused hercynite-corundum composite material and a preparation method thereof. The technical scheme is achieved by the following steps: firstly, using 34-44 wt% of Fe2O3 powder, 55-65 wt% of Al2O3 powder and 0.5-3 wt% of caustic-calcined magnesite powder as mixture, additionally adding 0.5-4 wt% of carbon powder of mixture; or, additionally adding 0.5-3 wt% of a bonding agent of mixture, uniformly stirring, drying a formed green body and then placing into a three-phase electric arc furnace, or directly uniformly stirring the raw materials and then placing into the three-phase electric arc furnace; secondly, fusing by adopting voltage of 90-220v, continuously smelting for 25-60min after all raw materials are smelted; or cooling smelted high-temperature synthesizedmaterials into the electric arc furnace for 24-48h, or guiding the smelted high-temperature synthesized materials into a water-cooling tank and cooling for 23-46h to obtain the hercynite-corundum composite material. The product prepared by the invention is the fused hercynite-corundum composite material comprising phase compositions of 80-98wt% of hercynite, 1-18wt% of corundum and 0.3-3wt% of magnesium aluminate spinel.

The invention discloses a periclase-pleonaste and hercynite/forsterite composite brick prepared by compounding a working layer and a heat insulation layer, wherein the working layer is prepared from magnesium-iron sand, hercynite sand and fused magnesite which serve as main raw materials; the heat insulation layer is prepared from medium-heavy synthetic olivine sand, medium-light synthetic boltonite sand, magnesite particles, fine magnesia powder and rice hull ash which serve as main raw materials; and the periclase-pleonaste and hercynite/forsterite composite brick is prepared through the steps of proportioning; mixing; molding; drying; sintering and the like. The working layer of the composite brick disclosed by the invention is strong in erosion resistance, good in thermal shock resistance and low in heat conductivity coefficient and is easily adhered to a kiln coating; the heat insulation layer is favorable in high-temperature volume stability, relatively high in mechanical strength and relatively low in heat conductivity coefficient. Therefore, the composite brick can be used for a high-temperature zone of a rotary cement kiln and is long in service life and capable of remarkably reducing the heat loss of a kiln body and has favorable energy-saving and emission reduction effects.

The invention belongs to the technical field of fireproofing materials, and relates to hercynite and a preparing method thereof. The chemical components of the hercynite are Fe2O3 and Al2O3, wherein mass proportion of the Fe2O3 to Al2O3 is (35 to 44) to (65 to 56); the chemical components are calculated on the foundation that the FeO is converted into Fe2O3. According to the hercynite, volume effect due to that iron changes among different valence states is avoided; the synthetic process is simple to carry out easily. According to the advantage of the preparing method, compared with an N2 atmosphere realizing by an enclosed condition, utilizing a reducing atmosphere which adopts air to bury carbon is very easy to operate.

The invention belongs to the technical field of fire resistant material production, and particularly relates to a wet process sintering production method for hercynite. The wet process sintering production method comprises the following steps: compounding 50-65% of aluminium oxide and 35-50% of metallic iron powder according to weight percentage, adding graphite, polyvinyl alcohol and water, grinding so as to obtain mud A, and performing dehydrating, vacuum pugging, drying and sintering on the mud A so as to obtain the hercynite, wherein the dosage of the graphite and the polyvinyl alcohol is respectively 1-5% and 0.1-0.3% of the total mass of the aluminium oxide and the metallic iron powder, and the amount of water is 1.0-1.2 times of the total mass of the aluminium oxide, the metallic iron powder, the graphite and the polyvinyl alcohol. The wet process sintering production method is simple in technology, low in labor intensity, environment-friendly and low in cost, the obtained hercynite is uniform in components and high in volume density, and the crystalline phase content reaches 97%.

The invention relates to a magnesium-hercynite-structured heat-insulating integral composite brick. The composite brick comprises a magnesium-hercynite heavy working layer and a light heat-insulating layer prepared from a light aggregate and powder. The integral composite brick is prepared from composed materials of the heavy working layer and the light heat-insulating layer. The length dimensional ratio of the heavy working layer to the light heat-insulating layer is 1-5:3-1. The invention also relates to a preparation method of the magnesium-hercynite-structured heat-insulating integral composite brick. According to the invention, the heavy layer and the light layer are combined, such that the thermal capacity can be reduced, creep deformation can be overcome, and the service life can be prolonged.

The invention discloses a low-heat-conductivity magnesia-hercynite brick used for a cement rotary kiln and a production method thereof. According to the invention, external temperature of a kiln body is reduced, and the effects of energy conservation and emission reduction are achieved. The magnesia-hercynite brick comprises the following components: high-purity magnesia or fused magnesia with a size of 3 to 1 mm, high-purity magnesia or fused magnesia with a size of 1 to 0 mm, high-purity magnesia or fused magnesia with a size of less than 0.088 mm, fused hercynite or sintered hercynite with a size of 2 to 0 mm, chemical fiber, and paper-pulp waste liquor with a concentration of 4 to 5%. The method comprises the following steps: material preparation, mixing and grinding, press molding into a green body, drying, and high-temperature sintering. According to the invention, uniform fiber micropores can be remained at a relative position in an internal structure of the magnesia-hercynite brick, so a gas-solid interface in the structure of a brick is increased; phonon dispersion of heat conduction of a solid phase is enlarged; heat conductivity of the brick is effectively reduced; and heat loss in a kiln is decreased.

The invention relates to a preparation method of nanoscale hercynite. The method comprises steps as follows: (1) a mixed solution of N,N-dimethyl formamide and water is prepared, wherein the volume fraction of the N,N-dimethyl formamide ranges from 65% to 85%; (2) an aluminum-containing compound, terephthalic acid and ferric acetylacetonate with the molar ratio being 15:10:3 are added to the solution prepared in Step (1) and evenly stirred, and a reactant solution is prepared; (3) the reactant solution prepared in Step (2) is aged in an airtight manner, then cooled to the room temperature and subjected to solid-liquid separation, and a hercynite precursor product is obtained; (4) the hercynite precursor product is placed in a high-temperature furnace for calcination and then cooled to the room temperature, and the nanoscale hercynite is obtained. Compared with the prior art, the preparation method has the advantages that the synthesis process is simple, the method is convenient to operate, the cost is low, the energy consumption is low and the like.

The invention relates to the field of refractory materials, and in particular relates to a casting material for prefabricated bricks for a feeding chamber. The casting material comprises the following components in parts by weight: 20-50 parts of white corundum, 18-30 parts of mullite M45, 15-40 parts of electric smelted magnesium aluminate spinel, 10-30 parts of electric smelted hercynite, 3-5 parts of zirconium carbonate, 2-3 parts of silicon micro powder, 2-8 parts of alumina micro powder, 0.1-1 part of sodium tripolyphosphate, 4-8 parts of aluminum oxynitride, 5-9 parts of Lafarge cement, 3-5 parts of a preservative solution, 5-10 parts of a first external binding agent, 2-7 parts of a second external binding agent, 3-7 parts of a first solid additive and 1.5-6 parts of a second solid additive, wherein the preservative solution is prepared by preparing a first primary mixed liquid and adding other components in sequence; the electric smelted magnesium aluminate spinel comprises 15-25 parts of electric smelted magnesium aluminate spinel granules of 5-8mm, 5-20 parts of electric smelted magnesium aluminate spinel granules of 3-5mm, 5-15 parts of electric smelted magnesium aluminate spinel granules of 1-3mm and 5-15 parts of electric smelted magnesium aluminate spinel granules of 0-1mm. The casting material is good in prefabricated brick strength, a cement clinker is unlikely to adhere to prefabricated bricks, and the service life is longer than 3 years.

The invention relates to the field of refractory materials, in particular to an abrasion-resistant anti-erosion pouring material for a cement kiln tertiary air duct. The abrasion-resistant anti-erosion pouring material is prepared from, by weight, 20-50 parts of white corundum, 18-30 parts of mullite M45, 15-40 parts of fused magnesium aluminate spinel, 10-30 parts of fused hercynite, 3-5 parts of zirconium carbonate, 3-5 parts of silicon carbide, 2-3 parts of silica micro powder, 2-8 parts of alumina micro powder, 0.1-1 part of sodium tripolyphosphate and 5-10 parts of additionally added binding agents. The fused magnesium aluminate spinel comprises 15-25 parts of fused magnesium aluminum pointed crystal particles ranging from 5 mm to 8 mm in particle size, 5-20 parts of fused magnesium aluminum pointed crystal particles ranging from 3 mm to 5 mm in particle size, 5-15 parts of fused magnesium aluminum pointed crystal particles ranging from 1 mm to 3 mm in particle size and 5-15 parts of fused magnesium aluminum pointed crystal particles ranging from 0 mm to 1 mm in particle size. The fused hercynite comprises 10-20 parts of fused hercynite particles ranging from 5 mm to 8 mm in particle size, 5-15 parts of fused hercynite particles ranging from 3 mm to 5 mm in particle size, 5-10 parts of fused hercynite particles ranging from 1 mm to 3 mm in particle size and 5-10 parts of fused hercynite particles ranging from 0 mm to 1 mm in particle size. The white corundum is formed by mixing white corundum with the particle size ranging from 1 mm to 5 mm with white corundum with the particle size ranging from 6 mm to 10 mm according to the mass ratio of 1:3-5. The pouring material is high in abrasion resistance, good in high temperature resistance and high in thermal shock resistance.

Disclosed herein are glass-ceramics having crystalline phases including β-spodumene ss and either (i) pseudobrookite or (ii) vanadium or vanadium containing compounds so as to be colored and opaque glass-ceramics having coordinates, determined from total reflectance—specular included—measurements, in the CIELAB color space of the following ranges: L*=from about 20 to about 45; a*=from about −2 to about +2; and b*=from about −12 to about +1. Such CIELAB color space coordinates can be substantially uniform throughout the glass-ceramics. In each of the proceeding, β-quartz ss can be substantially absent from the crystalline phases. If present, β-quartz ss can be less than about 20 wt % or, alternatively, less than about 15 wt % of the crystalline phases. Also Further crystalline phases might include spinel ss (e.g., hercynite and/or gahnite-hercynite ss), rutile, magnesium zinc phosphate, or spinel ss (e.g., hercynite and/or gahnite-hercynite ss) and rutile.

The invention discloses a method for preparing a magnesia-hercynite refractory material. The method comprises the following steps of: synthesizing the hercynite by using an electric smelting method; uniformly mixing the hercynite, magnesia and spent pulping liquor serving as raw materials according to a certain proportion, and sealing and baling the mixture; placing the prepared mixture into a mould for compression molding; drying the molded sample for 12 to 24 hours in a drying box; sintering the sample in a high temperature electric furnace; and cooling the sample to obtain the sintered magnesia-hercynite refractory material. The magnesia-hercynite refractory material prepared by the method has high kiln coating adherence, superior high temperature structural flexibility and superior cement clinker erosion resistance. The method has the advantages of simple process, high applicability and capability of being widely applied to various industries such as metallurgy, building materialsand the like.

The invention discloses novel environment-friendly blast furnace stemming which is characterized by comprising the following constituents by weight: 10 to 20 parts of disposable stemming, 5 to 15 parts of Yttrium mullite,10 to 20 parts of coal gangue rawore, 10 to 25 parts of modified magnesia-hercynite powder, 10 to 20 parts of modified clay, 10 to 33 parts of regenerative graphite electrode powder, 8 to 18 parts of a thickening agent, 3 to 8 parts of asphalt powder, 0.2 to 0.5 part of Glydol n 2002, 12 to 14.5 parts of an additive binding agent, and 0.1 part of nano-cellulose, wherein the thickening agent is a mixture of ferrovanadium ore and cupric oxide of which the weight ratio is 1 to 1. The stemming is low in cost, and high in air permeability, and can effectively maintain taphole reaming; during long-term storage, the service performance and operability of the stemming cannot decrease.

The present invention discloses a method for synthesizing high specific surface area hercynite through rapid combustion. According to the method, ferric nitrate, aluminum nitrate, urea and one or a plurality of materials selected from trimethylamine hydrochloride, triethylamine hydrochloride, diethylamine hydrochloride and dimethylamine hydrochloride are adopted as raw materials, mixing is performed according to an amount ratio of 1:2:(2-8):(0.1-3), the mixture is heated to achieve a liquid state, heating is continuously performed until the liquid combusts, and the obtained solid is grinded to obtain the hercynite material. According to the invention, the urea and the ammonium salt are adopted as the mixed fuel, and are subjected to the oxidation reduction reaction with the nitrate, the heat released from the combustion reaction is utilized to ensure the formation of the spinel, the large amounts of the gases released by the reaction make the material have the porous structure and the high specific surface area, and the preparation method has characteristics of simpleness, no requirement of sophisticated equipment, short time and high product purity, and is suitable for industrial mass production.

The invention discloses a stainless steel abrasive cutting wheel. The stainless steel abrasive cutting wheel is characterized in that abrasive cutting wheel raw materials comprise mixed abrasive particles, filler, a pore-forming material, resin and a reinforcing material; the mixed abrasive particles comprise black silicon carbide, monocrystalline fused alumina, brown fused alumina, brown fused alumina-cerium oxide core/shell composite abrasive particles and hercynite; the filler comprises zeolite and silicon carbide micro powder; the resin refers to phenolic resin modified by cardanol; and the reinforcing material refers to a glass fiber mesh containing graphite. The stainless steel abrasive cutting wheel has the advantages that first, the abrasive tool porosity is large and chips can be contained conveniently; second, the temperature of a grinding area is low and workpiece burning can be avoided; third, by the adoption of the chemico-mechanical polishing principle of cerium oxide, the microcosmic condition of a cut-processing surface is improved, and the roughness is lowered; fourth, due to the fact that different kinds of abrasive particles at different hardness are matched in the mixed abrasive particles, cutting efficiency is high; fifth, the cutting tool edge is narrow, the cutting surface is flat, and expensive cut materials are saved; sixth, by designing a grinding layer and a non-grinding layer, cost is reduced; and seventh, no fluoride is contained, and environmental pollution is reduced.

The invention discloses a method for treating sludge and sewage by using modified red mud and modified steel slag. The method comprises the steps of performing modification pretreatment on red mud and steel slag, adding the red mud and the steel slag into sludge, performing dehydration treatment, drying a dehydrated mud cake, performing high-temperature pyrolysis treatment on the dried mud cake, the modified red mud and the modified steel slag, preparing biochar-based hercynite, and using the biochar-based hercynite to treat sewage. According to the invention, co-treatment of the steel slag, the red mud and the sludge and recycling of the final product are realized. The method has important significance in expanding the application and application range of wastes such as the steel slag, the red mud and the sludge and improving the recycling rate of iron and aluminum resources; and the method can be widely applied to the field of sewage treatment, and the dual effects of degrading novel pollutants and adsorbing heavy metals are realized. The method disclosed by the invention has the characteristics of simple production process, easily available raw materials, wide product application range, good economic benefit and social benefit and the like.

The invention discloses a wide-temperature-range high-infrared-emissivity coating material and a preparation method thereof. The wide-temperature-range high-infrared-emissivity coating material is prepared by mixing wide-temperature-range high-infrared-emissivity powder and an adhesive in a weight ratio of 1:1-1:2.5. The wide-temperature-range high-infrared-emissivity powder is prepared from the following raw materials in percentage by weight: 5-30% of iron-ore-slag-base high-emissivity powder material, 25-50% of hercynite, 0-15% of magnetite, 0-20% of zirconium oxide, 20-40% of cerium oxide and 0-15% of molybdenum silicide. The adhesive is aluminum oxide sol. The wide-temperature-range high-infrared-emissivity coating material can be used on an aluminum oxide fiber refractory material surface, can be used at higher temperature, and has the high-infrared-emissivity energy-saving function and the surface reinforcement function.