83 results about "Cristobalite" patented technology

The invention provides equipment and a method for preparing high-purity cristobalite sand, and relates to the technical field of preparation of the high-purity cristobalite sand. The equipment comprises a connecting cylinder, a fixing ring is arranged on the inner wall of the connecting cylinder, and a supporting cylinder is fixedly connected to the inner wall of the connecting cylinder; after being crushed, quartz stone directly falls into a screen arranged in the supporting frame through the bottom of a connecting cylinder, meshes of the screen are gradually reduced downwards, so that the crushed quartz stone can be screened, a connecting plate is extruded, and the screen swings on the inner wall of the supporting frame; and a connecting plate is extruded by a screen in the direction away from the supporting frame through a first spring, so that the screen can return to the original position, the screen can shake back and forth on the inner wall of the supporting frame, the crushed quartzite can well pass through the screen, and then the quartzite can be quickly screened.

The invention provides a preparation method of low-cost high-purity crystalline cristobalite sand, which comprises the following steps: mixing and heating a silicon source, high-purity soda ash and deionized water in proportion to prepare high-purity water glass; the method comprises the following steps: mixing high-purity water glass and high-purity acid in proportion, stirring to form a precipitate, sealing, standing, carrying out segregation impurity removal by utilizing a growth process of gel, and then carrying out aging treatment; filtering and washing the precipitate by using deionized water, and drying to obtain amorphous high-purity silica gel powder; performing crystallization transformation and chlorination impurity removal on the amorphous high-purity silica gel powder; and cleaning the crystallized and impurity-removed cristobalite by using deionized water and dilute acid, and drying to obtain the high-purity crystalline cristobalite sand. The purity of the quartz sand prepared by the preparation method can reach 5N-7N grade, the preparation cost is lower, large-scale continuous production can be realized, meanwhile, the synthesized quartz sand is in a crystalline state, and the produced quartz glass product has lower bubble and floccule content and better mechanical, heat-resistant and optical properties.

This inorganic composition article is characterized by: being obtained by tempering a crystallized glass which contains, as the main crystal phase thereof, at least one selected from α-cristobalite and an α-cristobalite solid solution, and in which, when expressed as mass % of respective oxides, the contained amount of component SiO2 is not less than 45.0% but less than 68.0%, the contained amount of component Al2O3 is 3.0-15.0%, the contained amount of the component Li2O is 3.0-10.0%, the contained amount of component B2O3 is more than 0% but not more than 10.0%, the contained amount of component P2O5 is more than 0% but not more than 10.0%, the contained amount of the component ZrO2 is more than 0% but not more than 10.0%; and the mass ratio of SiO2 / (B2O3+Li2O) is 3.0-10.0; having a compressive stress layer on the surface thereof; and having a softening point (SP) of lower than 795° C.

The present invention relates to the technical field of quartz sand, and particularly relates to a method for preparing high-purity cristobalite, which method comprises: drying, calcining and scattering amorphous silica to obtain high-purity cristobalite. Compared with the prior art, the present invention has the following beneficial effects: 1, the amorphous silica has a relatively large specific surface area, with the surface thereof rich in hydroxyl, the cristobalite is apt to contain pores during the process of converting the amorphous silica into the cristobalite, and in order to eliminate the pores, the present invention uses a coupling agent for surface treatment and then conducts calcination, which results in, as shown in data, significant reduction in hydroxyl; and 2, under the condition of the same mass of the coupling agent, the inventor selects a silane coupling agent having a shorter chain, which results in fewer pores in the cristobalite and reduction in the calcining temperature and time to a certain extent, and possible reasons therefor are that the silane coupling agent is decomposed at a high temperature to form silicon oxide and the silicon oxide formed by decomposition has a smaller particle size and preferentially forms a crystal nucleus, thereby promoting the overall crystal form conversion.

The invention belongs to the technical field of aerogel preparation, and particularly relates to a method for generating cristobalite aerogel based on induction of potassium phosphate and magnesium phosphate. The preparation method comprises the following steps: firstly, introducing potassium phosphate or magnesium phosphate into tetramethoxysilane (TMOS) hydrolysate to prepare transparent SiO2 aerogel, and then carrying out centrifugal spinning and sintering treatment to obtain the cristobalite micro-nano fiber aerogel with a crystalline structure and a fiber structure. According to the method, a metal-induced crystallization mechanism is utilized, partial conversion from amorphous SiO2 to cristobalite crystal can be realized at a relatively low temperature, and the generated aerogel fiber has excellent mechanical properties and thermal stability. Meanwhile, the method is simple and convenient in process and low in cost, SiO2 crystallization can be realized at a relatively low temperature, and the application requirements of high-performance fiber aerogel are met.

The present invention relates to the technical field of graphene, and discloses a quartz-based graphene preparation method, which comprises: placing a quartz substrate in a reducing atmosphere at a temperature of 1160-1200 DEG C, and carrying out heat preservation for 100-140 min, the reducing atmosphere comprising hydrogen and an inert gas, and the hydrogen accounts for 5-10% of the total volume of the hydrogen and the inert gas; and introducing a carbon source gas, and depositing and growing graphene on the surface of the treated quartz substrate. According to the method, the proportion of hydrogen is reduced, the reducing capacity in the atmosphere is reduced, hydroxyl groups are gradually separated out from a quartz bulk phase, the quartz surface is in the oxygen-containing atmosphere, a substrate can be subjected to phase change at the temperature of 1,160-1,200 DEG C and is converted into a cristobalite crystal phase, the melting point of cristobalite can reach 1,700 DEG C, the tolerance temperature of the cristobalite is greatly increased, the deposition environment of graphene is improved, and the quality of graphene is improved.

The present disclosure relates to a reflective particulate composition comprising: a reflective pigment material comprising cristobalite, kaolin clay, and ATH; and at least 5% by weight of a hardener, based on the total solids weight of the composition. The present disclosure also relates to a building material comprising the reflective particulate composition. The present disclosure also relates to a method of making the reflective particulate composition.

This application relates to a method for preparing cristobalite sand and fused silica glass sand using waste quartz crucibles, wherein the method includes the following steps: 1) crushing and first screening the waste quartz crucibles, collecting the first undersize and the first oversize respectively; 2) subjecting the first oversize obtained in step 1) to high-temperature calcination to obtain a mixture containing a surface crystallized layer of cristobalite sand and fused silica glass sand separated; 3) subjecting the mixture obtained in step 2) to auto-grinding and second screening, taking the second undersize to obtain the first cristobalite sand, and taking the second oversize to obtain the first fused silica glass sand; 4) washing the first cristobalite sand in step 3), and performing wet screening to collect the third oversize for processing to obtain the first high-purity cristobalite sand, and collecting the third undersize for processing to obtain the second high-purity cristobalite sand.

The invention relates to an inorganic composition product which is formed by strengthening crystallized glass. The crystallized glass contains, as a main crystal phase, one or more substances selected from the group consisting of alpha-cristobalite and alpha-cristobalite solid solutions. The content of the SiO2 component is 50.0% to 75.0%, the content of the Li2O component is 3.0% to 10.0%, the content of the Al2O3 component is 5.0% to less than 15.0%, the content of the B2O3 component is more than 0% to 10.0% (inclusive), and the content of the P2O5 component is more than 0% to 10.0% (inclusive) in terms of mass% of oxides; the mass ratio of SiO2 / (B2O3 + Li2O) is from 3.0 to 10.0; the inorganic composition product has a compressive stress layer on the surface and has a four-point bending strength of 760 MPa or more.

The invention discloses a grain size grading design method of a low-shrinkage ceramic green body and application of the grain size grading design method in quartz ceramic preparation, and belongs to the technical field of ceramic materials. By optimizing the particle size grading of quartz, cristobalite crystallization in the preparation process of the quartz ceramic is promoted, the sintering densification is improved, and the mechanical property and the size stability of the quartz ceramic, especially the bending strength under the high-temperature condition, are remarkably improved.

The invention relates to the technical field of metallurgical coking, and provides a devitrification and CO erosion resistant zero-expansion silica brick and a preparation method thereof.The devitrification and CO erosion resistant zero-expansion silica brick is prepared from, by weight, 3-10 parts of nanoscale alpha-Al2O3, 15-35 parts of andalusite, 30-40 parts of high-purity fused mullite, 10-20 parts of superfine silica powder, 2-5 parts of silica sol binding agent and 3-5 parts of composite mineralizer. Through the synergistic effect of the design of the composite mineralizer and the stepped heat treatment process, the technical problems that the existing zero-expansion silica brick is easy to devitrify and crystallize fused quartz, poor in CO erosion resistance and lack of crystallization degree during long-term use at high temperature are solved; the thermal shock cycle index and the high-temperature breaking strength of the material can be improved, the formation of alpha-cristobalite crystallization peak is effectively inhibited, and the mass loss is reduced in a reducing atmosphere, so that the structural stability of the material is enhanced, and the service life of the material is prolonged.

To provide a method for producing a swellable layered silicate capable of producing a swellable synthetic layered silicate having a reduced amount of cristobalite impurities, and a method for reducing cristobalite.SOLUTION: A method for producing a swellable layered silicate comprises a heating step of heating and melting a mixture of raw materials for synthesizing the swellable layered silicate, and a cooling step of cooling the molten material melted by the heating step to at least 900°C at a cooling rate of 100°C / min or more to produce a mineral mass of the swellable layered silicate.SELECTED DRAWING: None

The application discloses a quartz crucible for single crystal silicon production and a preparation method thereof, relates to the technical field of crucibles, and contains a glass phase and a cristobalite phase, and the cristobalite phase is uniformly dispersed in the glass phase; the application adopts a mixture of amorphous synthetic quartz sand and cristobalite as a crucible preparation raw material, uniformly nucleates to form consistent phases inside and outside, significantly improves the stability of the crucible, effectively solves the problems of deformation such as bulging and wrinkling of the quartz crucible prepared from natural quartz sand in a high-temperature environment, and prolongs the service life of the crucible.

The invention relates to the technical field of semiconductor substrates and packaging fillers, and discloses spherical crystalline silicon oxide powder as well as a preparation method and application thereof. In the prior art, a substrate membrane material prepared by taking spherical crystal silicon oxide powder as a filler is easy to cause the problem of interface stripping. According to the invention, at least one connecting recess is arranged on the surface of at least 50% of particles in the spherical crystalline silicon oxide powder, and the maximum width of the connecting recess is less than 180nm under the observation of a non-metal spraying field emission electron microscope. Furthermore, through the arrangement of the connecting recesses on the surfaces of the particles in the powder, the connecting strength between the powder and the connecting material is enhanced, so that the peel strength between a packaging film material prepared by taking the spherical crystal silicon oxide powder as a filler and a copper foil layer is increased, and the problem of interface peeling caused by cristobalite crystals is solved.

The application relates to a method for preparing high-purity cristobalite sand and / or high-purity fused quartz glass sand by using waste quartz crucible, which comprises the following steps: 1) crushing and first screening the waste quartz crucible; 2) high-temperature roasting the first screening residue to obtain a mixture material in which a surface crystallization layer containing cristobalite sand is separated from fused quartz glass sand; 3) self-grinding and second screening the mixture material; 4) scrubbing the first crude cristobalite sand, removing the third screening residue by wet screening, taking the third screening residue to obtain high-purity cristobalite sand after treatment, and scrubbing the first fused quartz glass sand, removing the fourth screening residue by wet screening, and taking the fourth screening residue to obtain high-purity fused quartz glass sand after treatment. The application also relates to high-purity cristobalite sand and / or high-purity fused quartz glass sand prepared by using the above method.

A negative electrode active material for a nonaqueous electrolyte secondary battery has composite particles that include a lithium silicate phase, a silicon phase dispersed within the lithium silicate phase, and a crystalline phase of silicon dioxide dispersed within the lithium silicate phase. The crystalline phase of silicon dioxide includes β-cristobalite and quartz.

The application belongs to the field of new materials, and discloses an alumina ceramic with low thermal expansion coefficient, which is formed by sintering raw materials, the raw materials comprising: alumina: 98.5-99.1 wt%; silicon powder: 0.15-0.25 wt%; magnesium oxide: 0.15-0.25 wt%; yttrium fluoride: 0.15-0.25 wt%; and fused crystal beta-cristobalite: 0.25-0.75 wt%. The product is composed of four-element ceramic formula of Al, Si, Mg and Y, which meets the demand of the market for 99 alumina ceramic products with low thermal expansion coefficient, and greatly improves the application value of 99 alumina ceramic in ceramic substrates and electrostatic chucks. Meanwhile, the application also discloses a preparation method of the alumina ceramic.

The present disclosure relates to a reflective granular composition comprising a reflective pigment material including cristobalite, kaolin clay, and ATH; and at least 5 wt. % of a hardener, based on the total solids weight of the composition. The present disclosure also relates to a building material containing the reflective granular composition. The present disclosure also relates to a method for making the reflective granular composition.

The invention relates to a siliceous furnace lining material for a smelting environment with a high scrap ratio and a preparation method of the siliceous furnace lining material. The siliceous furnace lining material comprises the following components in parts by mass: 30-40 parts of selected microcrystalline silica tailings, 30-40 parts of fused quartz, 20-35 parts of spherical zirconium composite silica powder and 1-2 parts of a sintering aid. Wherein the SiO2 content of the selected microcrystalline silica tailings is greater than or equal to 99.5%. According to the present invention, the 99.5% selected microcrystalline silica tailings are adopted as the aggregate, such that the impurity reaction sites can be effectively reduced, the refractoriness can be increased to more than or equal to 1720 DEG C, and the spherical zirconium composite silica micro-powder is adopted as the matrix so as to effectively inhibit the cracking of the furnace lining and improve the fluidity of the slurry; boric acid in the sintering aid can promote low-temperature sintering to form a glass-phase combined phase. According to the siliceous furnace lining material for the smelting environment with the high scrap ratio, the sintering layer is specifically composed of the cristobalite phase and the silicon zirconium glass phase, and the siliceous furnace lining of an intermediate frequency furnace can be better protected.

A cristobalite includes: a d50 particle size selected within a range of from 1 μm to 15 μm; an L color coordinate of greater than 96; a color coordinate of less than 1; and a b color coordinate of 1 or less, in which the cristobalite is a powder. Also provided are compositions containing the cristobalite, coatings formed with compositions, and methods of preparing cristobalite.

The present invention provides cristobalite and a method for preparing the same. The method comprises the steps of: pre-treating waste quartz glass to obtain 80-200 mesh coarse quartz glass sand; alkali-leaching the coarse quartz glass sand to obtain refined quartz glass sand; subjecting the refined quartz glass sand to a high-temperature crystallization treatment to completely convert the amorphous fused quartz into a crystalline phase to obtain coarse cristobalite sand; and acid-leaching the coarse cristobalite sand to obtain refined cristobalite. The method has the advantages of high crystallization conversion, low environmental pollution, and high-quality finished products. Furthermore, by utilizing waste quartz glass as raw material, it alleviates the environmental pollution and space pressure of waste quartz glass, thereby conserving resources.

To provide a system for producing a silicon ingot by the horizontal magnetic field Czochralski method.SOLUTION: A system for producing a silicon ingot includes: a natural sand crucible containing a silicon melt in which a cristobalite layer having a thickness between 0.25 mm and 1.25 mm is formed on an inner wall of the crucible; magnetic poles for generating a horizontal magnetic field; and a controller programed to produce a silicon ingot according to the following steps: rotating the natural sand crucible containing a silicon melt at two to five revolutions per minute; applying a horizontal magnetic field to the crucible using the magnetic poles; contacting the silicon melt with a seed crystal; and withdrawing the seed crystal from the silicon melt while rotating the natural sand crucible at two to five revolutions per minute to form a silicon ingot.SELECTED DRAWING: Figure 4

The application relates to a doped optical fiber preparation process and discloses a high-uniformity and high-concentration Pr 3+ The application discloses a preparation method of a doped quartz-based glass optical fiber. Rare earth oxide Pr2O3, silica powder SiO2 and aluminum oxide Al2O3 are weighed, mechanically mixed, ball milled, dried, sieved, pre-sintered to be transformed into cristobalite, drawn into a glass rod containing a core by using a tube melting method, and processed to remove the outer cladding of the glass rod to obtain a core rod with adjustable diameter. The tube rod method is combined with a high-purity quartz tube to form an optical fiber preform rod. Finally, the optical fiber preform rod has high uniformity, low loss and high concentration of Pr 3+ The application discloses a drawing method of a doped quartz optical fiber. The aluminum oxide Al2O3 is introduced to improve the solubility of the rare earth ion Pr 3+ in the quartz glass and reduce the melting point of the quartz raw material. The rare earth doping concentration is adjustable. The raw material is transformed into cristobalite by pre-sintering, and the effect of reducing the bubbles of the core glass and improving the uniformity of the core glass is remarkable by combining the vacuum tube melting method.

The present invention discloses a method for designing particle size gradation for low-shrinkage ceramic green bodies and its application in the preparation of quartz ceramics, belonging to the field of ceramic materials technology. By optimizing the particle size gradation of quartz, the present invention promotes cristobalite crystallization during the preparation process of the quartz ceramics, improves sintering densification, and significantly enhances the mechanical properties and dimensional stability of the quartz ceramics, particularly their flexural strength under high-temperature conditions.

The present invention relates to a process for the production of a thermally blended material of amorphous silica-crystalline silica (thermally blended silica-PheniSilicTM) from silica-containing materials (e.g. Sand, cristobalite, cullet, waste rock powder / burrs from a process for producing artificial stones, waste products and by-products from mining and processing of natural quartzite). The invention also relates to an artificial stone product produced by using a base resin such as an unsaturated polyester, an epoxy resin, an acrylic acid or a combination thereof, and the reinforcement is a thermally blended material of amorphous silica-crystalline silica wherein the artificial stone has a bending strength of > = 40 N / mm2, a water absorption of < = 0.05%, an impact resistance of > = 3 J, and a tensile strength of > = 10 N / mm2. And a method for producing such an artificial stone.

The invention provides a high-strength cement-based grouting material and a preparation method thereof. The high-strength cement-based grouting material comprises the following components: Portland cement, fly ash, an expanding agent, quartz sand, a water reducing agent, a powder defoaming agent, a plastic expanding agent and a strength enhancer. Wherein the strength enhancer is prepared by taking rice hulls as a raw material, carrying out constant-temperature calcination to obtain rice hull ash, modifying one part of the rice hull ash with KH560, carrying out heating calcination on the other part of the rice hull ash, carrying out hydroxylation treatment on the other part of the rice hull ash, then carrying out KH550 modification, and finally carrying out blending reaction on the two parts of products. In the strength enhancer disclosed by the invention, products obtained by calcining rice hulls in two stages are respectively amorphous silicon dioxide and cristobalite, and after the rice hulls are modified by KH560 and KH550, an epoxy group is grafted on the surface of the amorphous silicon dioxide, and an amino group is grafted on the surface of the cristobalite. The early strength and the later strength of the cement-based grouting material can be remarkably improved through the interaction of the amorphous silicon dioxide, the cristobalite and the cement matrix.

The invention relates to a preparation process of doped optical fibers, and discloses a preparation method of high-uniformity and high-concentration Pr < 3 + > doped quartz-based glass optical fibers, which comprises the following steps of: weighing rare earth oxide Pr2O3, silicon dioxide powder SiO2 and aluminum oxide Al2O3, mechanically mixing, performing ball milling, drying and sieving treatment, performing pre-sintering treatment to convert into cristobalite phase, and sintering to obtain the high-uniformity and high-concentration Pr < 3 + > doped quartz-based glass optical fibers. The method comprises the following steps: drawing a glass rod containing a fiber core by using an in-tube melting method, processing to remove an external cladding of the glass rod to obtain a fiber core rod with an adjustable diameter, combining the fiber core rod with a high-purity quartz tube by using a tube-rod method to form an optical fiber preform, and finally drawing the high-uniformity, low-loss and high-concentration Pr < 3 + >-doped silica optical fiber. Aluminum oxide Al2O3 is introduced, so that the solubility of rare earth ions Pr < 3 + > in quartz glass is improved, the melting point of a quartz raw material is reduced, and the doping concentration of rare earth is adjustable; the raw materials are converted into cristobalite phases through pre-sintering treatment, and the effects of reducing bubbles of the fiber core glass and improving the uniformity of the fiber core glass are remarkable in combination with a vacuum tube inner melting method.

The invention discloses a method for converting 6N-grade quartz sand into high-purity alpha-cristobalite by doping and coating, and belongs to the technical field of inorganic non-metallic material preparation. The method comprises the following steps: with 6N-grade quartz sand as a raw material, coating the surface of the 6N-grade quartz sand with a silicic acid precursor containing alkali metal elements to form a coating layer; after drying, carrying out temperature-controlled crystallization at a relatively low temperature, inducing the quartz sand to generate lattice reconstruction from outside to inside by utilizing alkali metal in a coating layer, and converting the quartz sand into alpha-cristobalite; after crystallization, a surface coating layer and residual impurities are removed through an acid pickling process, the high-purity characteristic is recovered, and a high-purity alpha-cristobalite product is obtained. According to the method, efficient crystallization of the 6N-grade quartz sand at the relatively low temperature is achieved, the purity of the obtained product can reach the 6N grade, the crystal phase is pure, the light transmittance is excellent, the method can be widely applied to the fields of optical lenses, electronic packaging, aerospace high-temperature-resistant parts and the like, and the method has the advantages of being simple in process, low in energy consumption and suitable for large-scale production.

The present invention relates to process for producing a hot blended material of amorphous silicon dioxide - crystalline silicon dioxide (Hot Blending silica - PheniSilic™) from materials containing silicon dioxide such as sand, cristobalite, crushed glass, waste rock powder / burrs from process of producing artificial stone, waste products and by-products from the exploitation and processing of natural quartz stone. The present invention also relates to artificial stone product produced by using base resins such as unsaturated polyester, epoxy, acrylic or combination thereof and reinforcement is the hot blended material of amorphous silicon dioxide - crystalline silicon dioxide wherein the artificial stone has a flexural strength > 40N / mm2, a water absorption ≤ 0.05%, an impact resistance ≥ 3J, as well as process for producing this artificial stone.

The application relates to a preparation method of a photocured 3D printing silicon-based ceramic core with controllable cristobalite content, which comprises the following steps: preparing a pre-curing agent by mixing a silicon-based ceramic solid-phase powder and a liquid-phase solvent. The silicon-based ceramic solid-phase powder comprises a skeleton support agent, an auxiliary sintering agent and a cristobalite content regulating agent; the liquid-phase solvent comprises a viscosity regulator, an auxiliary curing agent, a powder aggregation inhibitor and a cross-linking auxiliary agent. The pre-curing agent is subjected to a photocured 3D printing process to obtain a ceramic core green body; the ceramic core green body is subjected to a debinding treatment and a sintering treatment to obtain the photocured 3D printing silicon-based ceramic core. The application can accurately regulate the content of cristobalite, reduce the use of the auxiliary sintering agent, simplify the composition of the ceramic core, reduce the number of micro-crack-containing particles in the microstructure of the silicon-based ceramic core material, weaken the stress concentration phenomenon caused by the micro-cracks, improve the high-temperature strength of the ceramic core and better be used for high-temperature alloy casting.