211 results about "Cristobalite" patented technology

The invention discloses high-strength lithium disilicate glass ceramic and a preparation method thereof. The glass ceramic comprises the following chemical components in percentage by weight: 59-80% of SiO2, 10-18% of Li2O, 0.1-14% of MgO, 0-15% of Al2O3, 1-8% of P2O5, 0-5% of Na2O, 0-7% of CaO, 0-9% of K2O, 0.5-8% of stabilizer and 0-10% of colorant, wherein the stabilizer is selected from one or more of ZrO2, SrO, BaO and Y2O3, and the colorant is selected from one or more of Eu2O3, CeO<+>, Tb4O7, La2O3, Ta2O5, MnO2 and Fe2O3. The lithium disilicate glass ceramic is a material which contains a residual glass phase, a Li2Si2O5 principal crystalline phase and a small quantity of Li3PO1, quartz, cristobalite, zirconium oxide or magnesium-aluminum silicate phase and is prepared by controlling nucleation and crystallization processes after carrying out heat treatment on lithium disilicate matrix glass. The lithium disilicate glass ceramic is very high in bending strength and fracture toughness and favorable in translucence and chemical stability and can serve as a full-ceramic dental material applied to the field of dental restoration.

The invention provides a fruit fresh-keeping paperboard and a preparation method thereof. The fruit fresh-keeping paperboard consists of paperboard base paper and fresh-keeping coat which is spread on the surface of the paperboard base paper. The paperboard base paper is mainly made from the waste paper, and the base weight is 90 to 100 g/m2. The fresh-keeping coat mainly comprises the following components in part by weight: 1 part of cristobalite, 0.25 to 1.5 parts of kaolin, 0.005 to 0.01 part of sodium polyacrylate, 0.0003 to 0.0005 part of nisin, 0.0001 to 0.0003 part of natamycin, 0.2 to 0.5 part of oxidized starch and 1.0 to 2.0 parts of water, and the base weight is 5 to 30 g/m2. The waste paper is made into the paperboard base paper through, disintegration, high-consistency slag removal, defibering, low-consistency slag emoval and screening, the cristobalite, kaolin, the sodium polyacrylate, the nisin, the natamycin and water are added into a high-speed dispersion machine to be made into pigment dispersion liquid after being adequately dispersed and filtered, and the oxidized starch and the water are heated to be dissolved to obtain the oxidized starch liquid. The pigment dispersion liquid is mixed with the oxidized starch liquid to obtain the fresh-keeping paint liquid, after being filtered by 180 to 200-mesh sieve, the fresh-keeping paint liquid is spread onto the surface of the paperboard base paper through a spreading machine, and the paperboard base paper with the surface being coated with the fresh-keeping paint is secondarily dried, press finished and decorated to obtain the finished product. The fruit fresh-keeping paperboard has the advantages that the fresh-keeping effect is good, the environment compatibility is good, the fresh-keeping package and the storage and transportation package are integrated, and the continuous mass production can be realized on the papermaking machine.

A method for rigidifying a fiber-based paper substrate for use in the exhaust system of a combustion device. In the method, a green ceramic fiber-based paper substrate is impregnated with an impregnating dispersion. The impregnated substrate is then dried, calcined and fired to form a rigidified substrate that is suitable for use in the exhaust system of a combustion device. This rigidification process is performed at least once and, preferably, two or more times. The green paper substrate comprises two or more sheets of green ceramic fiber-based paper, with at least one creased sheet and another sheet being a laminated together to form a plurality of tubular channels. The rigidified substrate comprises refractory ceramic fibers in the form of a ceramic fiber-based paper and agglomerates of ceramic particles. The ceramic particle agglomerates are bonded to and disposed so as to thereby bond together the refractory ceramic fibers at spaced locations along and at intersections of the refractory ceramic fibers so that the refractory ceramic fibers retain much of their original flexibility while in the paper.

Provided is lithium disilicate crystalline glass containing cristobalite crystal phase for high strength and aesthetic traits and its manufacturing process thereof. Exemplary embodiments of the present invention provide the high strength and aesthetic lithium disilicate crystalline glass, one kind of dental restoration materials, and its manufacturing method which induces the growth of the different crystal phase, cristobalite, from glass with lithium disilicate crystal.

The invention discloses a purple bronze glaze with metallic luster and a preparation method thereof. The purple bronze glaze with metallic luster is prepared from the following raw materials by weight through sintering: 4 to 12% of a ceramic catalyst, 20 to 28% of a crystallization agent, 2 to 6% of cristobalite, 32 to 58% of albite, 2 to 6% of calcined kaolin, 1 to 5% of alumina, 6 to 16% of calcined talcum, 2% of zinc oxide and 5% of high-boron frit, wherein the ceramic catalyst is a P-Al catalyst, and the crystallization agent is a P-Fe crystallization agent. According to the invention, chemical composition of a formula is reasonably adjusted, the leadless P-Al catalyst and the P-Fe crystallization agent are employed, a stable spinel crystal structure is obtained through recrystallization of the glaze, metal coloring ions (Fe<2+> and Zn<2+>) and the like are enriched on the surface of a glaze layer, so the whole surface of the glaze presents metal-like luster. The glaze shows a purple bronze metal effect, and the hardness of the glaze is almost equal to the glaze of common sanitary china; acid resistance and alkaline resistance of the glaze reach national standards in China; and defects like pin holes and small holes of the glaze are substantially improved, and the glaze is applicable to production under conventional production kiln condition.

The invention discloses cristobalite, a preparation method of the cristobalite and application of the cristobalite serving as a carrier of a catalyst. The cristobalite has a porous structure; the specific pore volume of the cristobalite is 0.5 to 0.7ml/g, the average pore size is 400 to 900nm, most probable pore size is 400 to 850nm, and the cristobalite contains 70 to 99.9 weight percent of silicon dioxide and 0.1 to 30 weight percent of tungsten component counted by oxide. The cristobalite serving as the carrier of the catalyst has a stable property at high temperature; the cristobalite disclosed by the invention has intrinsic properties of cristobalite prepared by other methods, the porous structure and potential industrial application value, and is expected to develop a new industrial application field of the cristobalite. The method for preparing the cristobalite, disclosed by the invention has the advantages of simplicity, low requirement on equipment and low energy consumption; in addition, the silicon dioxide raw material is easily obtained and abundant in reserves, so that the production cost is low.

A casting mold to cast a TiAl alloy includes a casting mold body formed into a bottomed shape and provided with a cavity. The casting mold body includes a reaction-resistant layer provided on the cavity side, formed from a refractory material containing at least one of cerium oxide, yttrium oxide, and zirconium oxide and a back-up layer formed on the reaction-resistant layer. The back-up layer includes a weakening layer formed from a refractory material including a silica material in a range from 80% by mass to 100% by mass inclusive, the silica material containing cristobalite in a range from 26% by mass to 34% by mass inclusive and the rest being fused silica, the weakening layer being designed to reduce casting mold strength and a shape-retention layer formed from a refractory material.

The invention discloses an improved silicon oxide ceramic core and a preparation method thereof and relates to a ceramic core and a preparation method thereof. The improved silicon oxide ceramic core disclosed by the invention is used for solving the problem that the conventional ceramic core is high in shrinkage rate and bad in high-temperature resistance. The product is prepared from ceramic slurry and a plasticizer, wherein the ceramic slurry is formed by mixing quartz glass powder, zircon power, analytically pure yttrium oxide and cristobalite; the plasticizer is prepared by mixing paraffin, beewax and polyethylene. The method comprises the following steps: 1, preparing the plasticizer; 2, preparing the ceramic slurry; 3, preparing a precast material; 4, preparing the improved silicon oxide ceramic core. The sintered shrinkage rate of the improved silicon oxide ceramic core is 0.041 percent and is far lower than the shrinkage rate of an existing silicon oxide ceramic core, the shrinkage rate is reduced by 0.193 percent, the high temperature deformation is 1.51mm and is lower than high temperature deformation of the existing ceramic core, and the high temperature deformation is reduced by 2.66mm. The method is simple in operation, and the experimental time is shortened.

The invention relates to a method for preparing monodisperse crystal silicon dioxide spherical particles by coating carbon, which mainly solves the problems of particle agglomeration, nonuniform size, irregular shape and high cost in the existing silicon dioxide crystal particle preparation process. The method comprises the following steps: (1) coating a carbon layer with uniform thickness on the monodisperse amorphous silicon dioxide spherical particle surface by an aerosol method or hydrothermal method to obtain core-shell structure silicon dioxide/carbon particles; (2) carrying out high-temperature treatment on the core-shell structure particles to crystallize amorphous silicon dioxide into quartz or cristobalite; and (3) removing the carbon layer by oxidation at low temperature to obtain the monodisperse spherical silicon dioxide crystal particles. The technical scheme provided by the invention solves the problems. The spherical monodisperse nano/sub-micro/micro silicon dioxide crystal particles can be used in catalysis, membrane separation, very large-scale integrated circuit packaging material and semiconductor industry, precision valves, hard disks, surface polishing treatment of magnetic heads and the like.

The invention relates to aventurine metallic luster glaze and a preparation method thereof.The aventurine glaze is prepared from, by weight, the raw materials of 30-50 parts of albite, 2-10 parts of cristobalite, 5-18 parts of calcined talc, 2-8 parts of aluminium oxide, 2-7 parts of zinc oxide, 4-15 parts of boron frit, 0-6 parts of calcined kaolin, 15-30 parts of catalyst, and 8-20 parts of crystallization agent.The preparation method of the aventurine metallic luster glaze comprises the steps that the raw materials are evenly mixed in proportion to obtain the total dry material, water is added in a certain proportion to be mixed, glaze slip with the concentration of 325-335g/ 200ml is obtained, and the glaze slip with the granularity smaller than or equal to 10 microns is controlled to range from 50% to 55%.By means of reasonable adjustment of the firing process system and optimization of chemical composition of the formula, during later condensation after high-temperature firing, many micro ferric oxide crystalline granules are separated out from the glaze of the aventurine glaze produced in the invention, and many isolated flake-shaped single crystals sparkling like small gold foils are formed, so that an aventurine metallic glaze effect is shown.

The invention relates to a copper clad laminate with a low dielectric constant and a manufacturing method of the copper clad laminate, and belongs to the technical field of the copper clad laminate. A method for acquiring cristobalite with alkali resistance and the low dielectric constant is provided, composition of a resin mixture of the copper clad laminate is improved, and the copper clad laminate with the low dielectric constant is obtained. The problem of a method for acquiring the low dielectric constant by the aid of modified resin or resin with the low dielectric constant all the time is solved, inorganic filler with the low dielectric constant is added more economically and more conveniently, and specifically, the method for reducing the dielectric constant of the copper clad laminate by adopting cristobalite powder prepared from vein quartz ore as inorganic filler composition is provided.

Provided is a sputtering target for a magnetic recording film containing SiO₂, wherein the sputtering target for a magnetic recording film contains B (boron) in an amount of 10 to 1000 wtppm. An object of this invention is to obtain a sputtering target for a magnetic recording film capable of inhibiting the formation of cristobalites in the target which cause the generation of particles during sputtering, shortening the burn-in time, and realizing a stable discharge with a magnetron sputtering device.

The invention discloses a method of separating and purifying montmorillonite from calcium bentonite. The method includes: adding dispersants such as sodium carbonate into a bentonite suspension, adjusting the pH value of the suspension, separating to obtain primarily-purified montmorillonite, adjusting the pH value of a suspension of the primarily-purified montmorillonite to a certain value, performing ultrasonic wave processing, and separating to obtain the high-purity montmorillonite. The chemical structure of the montmorillonite is unchanged. A superfine cristobalite impurity concomitant with the montmorillonite in the calcium bentonite is effectively removed. By ultrafine particle dispersion, the superfine cristobalite particles and the montmorillonite are depolymerized, thus enhancing dispersion and suspension capability of the superfine cristobalite particles and the montmorillonite. The cristobalite is removed by utilization of fractional centrifugation so as to obtain the high-purity montmorillonite, thus solving the technical problem that the cristobalite is hard to remove in the montmorillonite purification. The method has characteristics of simple process, mild conditions, cheap and easily available raw materials, low equipment requirements, high added value of products, and the like.

A sintered compact sputtering target configured from an alloy having a composition comprising Pt at a molecular ratio of 35 to 55% and remainder being Fe, and a nonmagnetic substance dispersed in the alloy, wherein the nonmagnetic substance contains at least SiO₂, SiO₂ is amorphous, and a residual oxygen amount, which is obtained by subtracting an amount of oxygen contained as a constituent of the nonmagnetic substance from a total amount of oxygen contained in the target, is 0.07 wt % or less. An object of this invention is to provide a sintered compact sputtering target having a structure in which a nonmagnetic substance containing SiO₂ is dispersed in an Fe—Pt-based alloy and capable of suppressing the crystallization of SiO₂ into cristobalite, and reducing the amount of particles that is generated during sputtering.

The invention discloses a method for preparing a cristobalite material by taking a quartz crucible as a raw material, which adopts the quartz crucible subjected to high temperature treatment of 1,400 to 1,600 DEG C is subjected to surface impurity removal, crushing and grinding processes to obtain a high-purity cristobalite material of which the SiO2 content is more than 99 percent by weight. The method has the advantages of simple production process, low production cost, good product quality, energy conservation, environmental protection and the like.

This invention relates to a method for preparing mullite by calcining coal gangue. The method comprises: (1) mixing coal gangue powder and additive uniformly; (2) heating the mixed raw materials at a rate of 2-10 deg.C/min to 1300 deg.C, and keeping the temperature for 3h to obtain the product. The additive is composite catalyst of NaF and La2O3. The addition amounts of NaF and La2O3 are 1-2 wt. % and 0.1-0.5 wt. % of coal gangue powder, respectively. The method has such advantages as low energy consumption and low cost. The mullite product does not contain quartz phase that is harmful to mullite properties.

The invention disclose a preparing method of cristobalite through calcining quartz, which comprises the following steps: 1) mixing quartz power and phase-change activator; getting batches; compositing Y2O3,Na2CO and BaF2 as phase-change activator; making the adding quantity of Y2O3, Na2CO3 and BaF2 separately at 1 per mill -5 per mill , 5 per mill -10 per mill and 1 per mill -5 per mill against the weight of quartz power; 2) heating the batches up to 1300 deg.c with speed of 2-10 deg.c per minuet; keeping temperature at 1300 deg.c at 6 h; getting product with quartz phase bigger-than 94%.

The invention provides an investment casting technology for a copper alloy casting. Chlorcosane, Fischer-tropsch wax, stearic acid, glycerol ester of rosin, microcrystalline wax, polypropylene wax, polyisobutene, polyurethane elastomers and aldehyde resin serve as mold materials; and the polyisobutene, the polyurethane elastomers and the aldehyde resin are inserted into the chlorcosane, the Fischer-tropsch wax, the microcrystalline wax, the polypropylene wax and the stearic acid in a penetrating manner, and a formed structure has the good strength and the good heat stability. As for coatings adopted in the investment casting technology, cristobalite has the complete chemical inertness, and splitting decomposition can not occur at a quite high temperature; fused alumina has the beneficial effects of being high in melting point, compact in structure, good in heat conductivity and the like, the thermal expansion coefficient is small, and thermal expansion is even; and boron nitride is quiet low in friction coefficient, quite good in high-temperature stability and heat shock resistance, quite high in strength and heat conduction coefficient and lower in expansion coefficient. In this way, the copper alloy casting obtained with the investment casting technology for the copper alloy casting is high in strength and good in tenacity, no crack is generated on the surface, and the product quality is reliable.

The invention discloses a gypsum mould material for casting a precision fusible pattern, characterized in that the gypsum mould material is prepared by respectively mixing 30 to 50% by weight of 10 mum cristobalite, 35 to 60% by weight of 30 mum cristobalite, 15 to 25% by weight of alpha gypsum, 1 to 5% by weight of time regulator and a coating intensifier. By using noble metals such as gold, silver and platinum, the invention can be used for preparation of the precision casting. The mould procedure can be carried out even at high temperature when injecting the molten metal, no crack will be generated and excellent dispersivity is obtained.

A new pozzolanic material basically conformed of microsilica with a minimum of silica of 85% in its composition is described, where the silica of the material is conformed mainly of cristobalite and tridimite. Unlike microsilica conformed basically of quartz, the microsilica of the invention exhibits greater pozzolanic indexes and provides improved characteristics of durability to concrete cements and in smaller proportions. Also simple and low consumption energy methods for obtaining the pozzolanic material of the invention are described.

A sputtering target for a magnetic recording film containing SiO₂, wherein a peak strength ratio of a (011) plane of quartz relative to a background strength (i.e. quartz peak strength/background strength) in an X-ray diffraction is 1.40 or more. An object of this invention is to obtain a sputtering target for a magnetic recording film capable of inhibiting the formation of cristobalites in the target which cause the generation of particles during sputtering, shortening the burn-in time, magnetically and finely separating the single-domain particles after deposition, and improving the recording density.

The invention belongs to the field of ceramic industry, and discloses a method for manufacturing high-tenacity ceramics through tricalcium phosphate. The method comprises the following steps that, by weight, 5%-15% of the tricalcium phosphate and 85-95% of ceramic blanks are evenly smashed, mixed, milled in the mode of wet ball milling, dried and ground into powder, green ceramic bodies are manufactured through dry pressing molding and the green ceramic bodies are sintered in a kiln to form the high-tenacity ceramics. According to the high-tenacity ceramic samples manufactured through the method, needle-shaped mullite and anorthite serve as the main crystalline phase, cristobalite serves as the auxiliary crystalline phase, and a Si-O system and P-O system composite glass phase serves as the binding phase. Through the structure, thermal expansion coefficients between the crystalline phases and between the crystalline phases and the glass phase are better matched, micro-cracks can be effectively reduced in the ceramic sintering process, and the tenacity of ceramic products is greatly improved.

The invention discloses a preparation technology of silicon carbide foam ceramic. The preparation technology comprises the steps of raw material preparation, mixed solution preparation, ball milling, modifying firing and the like. The silicon carbide foam ceramic is prepared by an organic foam impregnation technology, MgO-Al2O3-SiO2 is introduced as a sintering aid system, and the main crystal phases of the silicon carbide foam include mullite, cordierite, cristobalite and alpha-silicon carbide. The silicon carbide foam ceramic prepared by the system has the strength up to 1.23MPa as well as excellent high-temperature resistance and is applicable to molten iron filtration.

The invention discloses a method for firing porous cristobalite at low temperature by adopting diatomite as a raw material. The method comprises the following steps of: adding diatomite powder into an additive solution, wherein the addition amount of diatomite is 1g/2-5ml according to the ratio of the mass of the diatomite/the volume of the additive solution; fully stirring, and then drying, wherein the additive solution is sodium metasilicate or alkali-metal silicate solution with the mass fraction being 7.20-17.33%; heating the dried solids to 600-800 DEG C, and calcining for 12-24 hours to obtain the porous cristobalite. The method disclosed by the invention has the beneficial effects that since the calcining temperature is low, the cristobalite product retains the morphology of the cristobalite and has abundant pore-channel structures so as to achieve unique and good heat retaining property. The prepared cristobalite has the intrinsic property of other synthesized cristobalites, also retains the morphology of the cristobalite and has abundant pore-channel structures so as to achieve good heat retaining property. The method disclosed by the invention has the advantages of low energy consumption, simple process and low cost and the product has high potential industrial value.