247 results about "Silicon tetrachloride" patented technology

The invention relates to a continuous production method of high-purity tetraethoxysilane, and belongs to the technical field of tetraethoxysilane preparation. The method comprises a raw material pretreatment stage and a purification and rectification stage: in the pretreatment stage, silicon tetrachloride and ethanol are subjected to an esterification reaction in a molar ratio of 1: (3-4) under the protection of nitrogen, the pH is adjusted to be neutral through triethylamine, and triethylamine hydrochloride is removed through reduced pressure distillation; then, a cerium oxide-molecular sieve composite adsorbent with the specific surface area larger than or equal to 800 m / g and the pore diameter of 2-5 nm is adopted for dehydration under the pressure of 0.8-1.2 MPa till the water content is smaller than or equal to 5 ppm, and volatile impurities are removed through high-purity nitrogen purging; in the purification stage, metal ions and Cl are synergistically removed through a titanate modified resin layer and a nano TiOtube layer, and then step-by-step separation is performed through a four-stage differential pressure rectifying tower. Through collaborative optimization of structural design of the composite adsorbent, construction of an organic-inorganic hybrid interface of the resin layer and pressure gradient rectification, 72-hour continuous production is achieved, the single-pass yield of the product is 92%, and the total amount of metal impurities is smaller than or equal to 5 ppb.

The invention relates to a silicon imine production method adopting a continuous method. The method comprises the following steps: by taking liquid ammonia as a liquid medium, turbulence the liquid ammonia from top to bottom along the inner wall of the falling-film tubular reactor; spraying silicon tetrachloride in a mist form to form gaseous silicon tetrachloride; carrying out gas-liquid reaction on the gaseous silicon tetrachloride and liquid ammonia to obtain a silicon imine solid reaction product; in the aging device, gaseous silicon tetrachloride which is not completely reacted continuously reacts with liquid ammonia; the filter is used for filtering a silicon imine solid reaction product; the separator is used for separating ammonia gas and ammonium chloride. In this way, waste discharge is reduced through continuous production. Then, in combination with a deep learning algorithm, an implicit change mode of real-time pressure data in the reactor can be mined, consumption of reactants and accumulation of products in the reactor can be learned and understood from the implicit change mode, and intelligent spraying of gaseous silicon tetrachloride is realized based on the condition.

The invention belongs to the technical field of electrochemical synthesis, and particularly relates to a method for electrochemical synthesis of dichlorodiphenyl silane by using benzene and silicon tetrachloride as raw materials, which comprises the following steps: using a diaphragm-free electrolytic bath, adding electrolyte, benzene and silicon tetrachloride into the electrolytic bath to form a reaction system, and generating dichlorodiphenyl silane under the protection of inert gas under the electrolysis condition, the electrolyte is composed of acetonitrile as a solvent, a supporting electrolyte and a buffer solution. The reaction does not need a transition metal catalyst, a high-temperature and high-pressure condition, an oxidizing agent or a reducing agent, electrons are directly used as the oxidizing agent, the method is green and environment-friendly, a reaction device is simple and convenient to operate, and the yield can be stabilized at about 70%.

The invention discloses a method for recycling silicon industry by-product silicon tetrachloride based on gallium electrode electro-deposition, which is used for solving the problems of low solubility and crystal structure in the process of preparing silicon by an electro-deposition method. According to the method, a deep eutectic solvent system composed of 1, 3-dimethyl-2-imidazolinone and 1, 3-dimethylurea is adopted to efficiently absorb silicon tetrachloride in a green manner and prepare the electrolyte, and the electrolyte is converted into high-purity, uniform and compact silicon crystals by using a liquid gallium electrode electrodeposition technology, so that effective conversion from wastes to high-added-value materials is realized. Meanwhile, the low-toxicity eutectic solvent which is easy to prepare and has good biodegradability is adopted to replace traditional ionic liquid or other chemical reagents, so that the safety, the environmental protection property and the sustainability of the process are remarkably improved, and the treatment cost and the environmental burden are reduced at the same time.

The present invention discloses a method for separating nickel and iron from a nickel-iron alloy by chlorination roasting: (1) placing the nickel-iron alloy in a roasting furnace; (2) introducing a gaseous chlorinating agent into the roasting furnace for staged roasting to obtain roasting slag and a roasting gas phase; wherein the gaseous chlorinating agent is a mixture of chlorine and gaseous ferric chloride; and (3) condensing the roasting gas phase obtained in step (2) in stages to obtain solid ferric chloride and liquid silicon tetrachloride, respectively. The present invention controls the composition of the chlorinating agent during the chlorination roasting process to achieve selective and directional volatilization of iron into the gas phase while preventing nickel from being chlorinated. Thus, nickel and iron in the nickel-iron alloy can be separated in a single step, and the process flow is short.

The invention discloses a device and a process for continuously preparing alpha-phase silicon nitride by a precursor method, and relates to the technical field of preparation of alpha-phase silicon nitride. In the process provided by the invention, the raw material silicon tetrachloride directly reacts with liquid ammonia in the reactor in a vaporific form under the action of high-purity nitrogen through an atomizer, and meanwhile, the by-product ammonium chloride solid generated by the reaction can be ensured to be completely dissolved in the liquid ammonia through the reaction temperature and the reaction pressure and by limiting the feed flow ratio of the raw material silicon tetrachloride to the liquid ammonia; the content of ammonium chloride impurities in generated solid material precursor silicon imine is reduced, and the impurity decomposition amount during subsequent calcination is reduced while the product purity is improved.

The invention belongs to the technical field of aluminum electrolysis waste treatment, and particularly relates to a method for green recovery of aluminum electrolysis waste. The method comprises the following steps: mixing and roasting aluminum electrolysis waste, aluminum-containing waste and sulfuric acid to prepare modified waste; the modified waste is smashed and stirred, and filter residues A and filtrate A are filtered and separated out; removing impurities from the filtrate A to obtain filter residues B and filtrate B; reacting the filtrate B with water-soluble carbonate or phosphate to prepare a lithium product; mixing and roasting the filter residue A, the filter residue B and a silicon-containing substance to generate aluminum oxide and silicon tetrafluoride gas; dissolving the aluminum oxide through hydrochloric acid, and reacting the silicon tetrafluoride gas with an aluminum chloride solution to form silicon tetrachloride gas and aluminum fluoride; the silicon tetrachloride gas is combusted to generate hydrogen chloride gas and silicon dioxide particles, and the hydrogen chloride gas is converted into a hydrochloric acid solution through water absorption. According to the method, recycling of aluminum and lithium resources in the aluminum electrolysis waste is effectively achieved, by-products are converted into valuable chemical substances, and resource recycling is promoted.

The invention discloses a high-purity quartz lump and a preparation method and application thereof, and relates to the technical field of quartz lumps, artificially synthesized high-purity quartz sand is used as a raw material, compared with an existing quartz lump prepared from natural quartz sand, the prepared quartz lump is better in quality, the total content of impurity elements is smaller than 2 ppm, the content of a single impurity element is smaller than 1 ppm, and the purity of the quartz lump is higher than that of the quartz lump prepared from natural quartz sand. The transmittance in a 165 nm deep ultraviolet band is greater than 80%, the hydroxyl content is less than 30 ppm, and no bubble or gas line exists; compared with a method for preparing a quartz lump by using silicon tetrachloride as a raw material, the preparation method of the quartz lump provided by the invention is more environment-friendly.

The invention belongs to the technical field of silicon carbide coatings, and particularly relates to a method for quickly depositing a silicon carbide coating through CVD (Chemical Vapor Deposition), which comprises the following steps: pretreating a graphite substrate; debugging the equipment; placing the pretreated substrate in a reaction furnace, closing a furnace door, starting a vacuum system, pumping the pressure in the reaction furnace to-Pa, and reducing the interference of air in the furnace on the reaction; introducing a small amount of hydrogen into the reaction furnace, rapidly raising the temperature in the furnace to 800-900 DEG C, maintaining the temperature, then introducing a very small amount of silicon source and carbon source gas, and carrying out preliminary deposition on the surface of the substrate; and hydrogen, silicon tetrachloride and methane are sequentially introduced. The preparation method of the CVD silicon carbide coating can solve the problems of low deposition rate, long preparation period and the like when the existing CVD process is used for preparing the silicon carbide coating, so that the production efficiency can be greatly improved, the cost can be reduced, and the preparation method has important significance in promoting the application of the silicon carbide coating in more fields.

The invention relates to a preparation method of silicon dioxide-boron nitride nanobelt aerogel, which comprises the following steps: dissolving melamine and boric acid in a co-solvent of tert-butyl alcohol and hot deionized water, stirring and mixing, carrying out ultrasonic treatment, freeze-drying and the like to obtain a melamine-boric acid aerogel precursor, placing the precursor in a tubular furnace, and carrying out vacuum drying to obtain the silicon dioxide-boron nitride nanobelt aerogel. Pyrolyzing in an ammonia gas atmosphere to obtain boron nitride nanobelt aerogel; and placing the boron nitride nanobelt aerogel in a xylene solution containing tetraethoxysilane and silicon tetrachloride, taking out the boron nitride nanobelt aerogel, and drying the boron nitride nanobelt aerogel. And hydrolyzing and pyrolyzing in an inert atmosphere to form a silicon dioxide layer on the surface, thereby obtaining the silicon dioxide-boron nitride nanobelt aerogel. The silicon dioxide and boron nitride nanobelt aerogel is low in density and excellent in mechanical property and oxidation resistance.

The invention discloses a production method of hexachlorotrisiloxane. Production devices mainly comprise a reaction synthesizer, a condensation system, a rectification system, a final-stage condensation system and a storage system. The method comprises the following steps: reacting raw materials silicon tetrachloride and primary alcohol according to a certain ratio under the catalytic action of a boron Lewis acid catalyst in an environment that the reaction temperature is controlled to be 650-800 DEG C and the reaction pressure is controlled to be 0.6-0.8 MPa to obtain a mixed gas of hexachlorotrisiloxane and a by-product; and the high-purity hexachlorotrisiloxane is obtained after cooling of the condensation system and separation of the rectification system. The invention breaks through the blank of the production process of the hexachlorotrisiloxane in China, thereby eliminating the dependence of the demand of the hexachlorotrisiloxane product in China on foreign import, providing a stable production process, expanding the productivity of the hexachlorotrisiloxane, and realizing the production of the high-purity hexachlorotrisiloxane product. The problems of high-end industries in China are solved, and sustainable development of related industries in China is promoted.

The invention discloses a method for co-producing triphenylphosphine and silicon tetrachloride, which comprises the following steps: S1, mixing triphenylphosphine oxide with a solvent, heating to 90-110 DEG C, and dropwise adding trichlorosilane to carry out reduction reaction; the reaction pressure is controlled to be 0.12 to 0.20 Mpa absolute pressure; s2, the reaction temperature is kept not lower than 90 DEG C, preferably 90-110 DEG C, meanwhile, the system pressure is adjusted to be negative pressure, and the reaction continues for 0.5-3 h; and after the reaction is completed, rectifying and separating out silicon tetrachloride, adding water into the residual reaction liquid for quenching, filtering out insoluble substances, and removing the solvent to obtain the triphenylphosphine. According to the method, high-purity triphenylphosphine can be obtained with high yield, the electronic-grade silicon tetrachloride is co-produced, the generation of silicon dioxide is reduced, the gel coating problem of the silicon dioxide and the product loss are reduced, the post-treatment is more convenient, and the method is suitable for industrial production.

The utility model provides a system for synthesizing trichlorosilane. The system for synthesizing trichlorosilane comprises a trichlorosilane synthesis reaction device, a first gas-solid separation unit, a first tail gas treatment unit, a silicon tetrachloride hydrogenation reaction device, a second gas-solid separation unit, a second tail gas treatment unit and a product separation and purification unit. According to the system, through the technological process of fusing the trichlorosilane synthesis reaction and the silicon tetrachloride hydrogenation reaction, efficient utilization of silicon powder, hydrogen and silicon tetrachloride is achieved, the investment and operation cost is saved, and meanwhile the raw material consumption is reduced.

The invention discloses a manufacturing process for synthesizing high-purity quartz sand by a silicon tetrachloride liquid-phase hydrolysis method, which comprises the following process steps in sequence: carrying out liquid-phase hydrolysis on silicon tetrachloride and water, and then washing, carrying out solid-liquid separation, drying, calcining, grinding and screening the hydrolysis product to finally obtain high-purity quartz powder, a heating process is carried out while solid-liquid separation is carried out, or the heating process is carried out between the washing process and the solid-liquid separation process; or a heating process is carried out while the washing process is carried out. The orthosilicic acid in the hydrolysate is easier to decompose into metasilicic acid due to heating; in this way, metasilicic acid almost completely exists during solid-liquid separation, only filter residues of metasilicic acid particles exist on the filter screen and are easy to transfer, and the problem that colloidal precipitated orthosilicic acid filter residues are difficult to transfer is solved. Loss of orthosilicic acid is avoided as far as possible, raw material consumption is reduced, preparation cost is reduced, and the filter screen is convenient to clean.

The electronic-grade silane gas continuous production preparation system comprises a cold hydrogenation treatment device, an inlet of the cold hydrogenation treatment device is connected with a raw material supply system, and an outlet of the cold hydrogenation treatment device is connected with a cold hydrogenation rectifying tower through a pipeline. The cold hydrogenation rectifying tower is sequentially connected with the boron and phosphorus removal adsorption column, the first-stage disproportionator, the first tower, the second tower, the second-stage disproportionator, the third tower and the fourth tower through pipelines, and electronic-grade silane in the fourth tower is used for being conveyed to a silane tank area; the first tower is used for removing silicon tetrachloride produced after the disproportionation reaction of the first-stage disproportionator; the second tower is used for separating the extracted chlorosilane material; the third tower is used for separating silane from chlorosilane; and the fourth tower is used for discharging light impurities and heavy impurities and conveying gas-phase electronic-grade silane into a silane tank area. The device and the method realize continuous, efficient and high-purity production of the electronic-grade silane gas, and have the advantages of low energy consumption, low cost, thorough impurity removal and the like.

The invention relates to the field of inorganic nonmetal powder materials, and discloses a preparation method of silicon nitride powder, which comprises the following steps: (1) mixing a surfactant, liquid ammonia and an organic solvent to form a to-be-reacted solution, and mixing the to-be-reacted solution with a silicon tetrachloride solution for substitution reaction to obtain a solution containing silicon imine suspended matters; the surfactant is selected from one or more of sodium dodecyl sulfate, polyvinylpyrrolidone, sodium stearate, sodium dodecyl benzene sulfonate, fatty acid methyl ester ethoxylate sulfonate, fatty acid sorbitan, polysorbate-20 and polysorbate-80; the surfactant is selected from one or more of sodium dodecyl sulfate, polyvinylpyrrolidone, sodium stearate, sodium dodecyl benzene sulfonate, fatty acid methyl ester ethoxylate sulfonate, fatty acid sorbitan, polysorbate-20 and polysorbate-80; (2) carrying out suspended matter extraction and impurity removal on the solution containing the silicon imine suspended matter to obtain silicon imine powder; (3) performing thermal decomposition on the silicon imine powder to obtain amorphous silicon nitride powder; and (4) crystallizing the amorphous silicon nitride powder to obtain the alpha-phase silicon nitride powder. The method can reduce the impurity content and agglomeration degree of the precursor so as to improve the quality of the silicon nitride powder.

The utility model provides a tail gas pre-washing device, which relates to the technical field of polycrystalline silicon production and comprises a filter for separating a gas phase and a solid phase in dust-containing tail gas; the tail gas pre-washing tower is provided with a to-be-washed gas inlet, a leacheate inlet, a pre-washing tower gas phase outlet and a pre-washing tower liquid phase outlet; the to-be-washed gas inlet is connected with the gas phase outlet of the filter; the leacheate inlet is positioned above the to-be-washed gas inlet; wherein the leacheate inlet is used for introducing silicon tetrachloride into the tail gas pre-washing tower; and a stream at a gas phase outlet of the prewashing tower flows to the compressor. The tail gas pre-washing tower is used for washing and dedusting, so that the problems of abrasion of the compressor and blockage of the interstage cooler are solved. The silicon tetrachloride is used as the leacheate of the tail gas pre-washing tower, so that chlorosilane can be absorbed without introducing other impurities, the waste of chlorosilane is reduced, the load of a rear-end tail gas leaching system is reduced, and meanwhile, the silicon tetrachloride can also be recycled.

The utility model belongs to the technical field of new energy photovoltaic silicon material preparation, and discloses a high-density rapid fluidized bed reactor for hydrogenation reduction of silicon tetrachloride. The reactor consists of a high-density rapid fluidized bed, a cyclone separation system and a material returning system, wherein a turbulent fluidization section is connected with a rapid fluidization section through a reducing and reducing section; a first gas inlet, a distribution plate, a gas distributor, a particle feeding hole, a first material return inlet, a second gas inlet and a second material return inlet are sequentially arranged on the cone bottom, the turbulent flow fluidization section and the rapid fluidization section of the high-density rapid fluidized bed; particles separated by the first-stage cyclone separator of the reacted gas-solid mixture return to the turbulent flow fluidization section, and particles separated by the second-stage and above cyclone separators return to the rapid fluidization section. The high-density rapid fluidized bed reactor designed by the utility model has the advantages of full gas-solid contact, rapid heat transfer and mass transfer, higher hydrogenation reaction conversion rate, high operation flexibility and high volume utilization rate.

The invention provides a photovoltaic glass surface self-cleaning coating and a preparation method thereof.The photovoltaic glass surface self-cleaning coating is prepared from a dehydrated organic solvent, 1-7 parts by mass of tetramethyl orthosilicate, 2-15 parts by mass of fluorosilane hydrophobic coupling agent, 10-20 parts by mass of silicon tetrachloride, 1-10 parts by mass of hydrophobic silane coupling agent, 5-15 parts by mass of dichloro (methyl) (3, 3, 5-trimethyl-1, 3, 5-trimethyl-1, 3, 5-trimethyl-1, 3, 5-trimethyl-1, 3, 5-trimethyl-1, 3, 5-trimethyl-1, 3, 5-trimethyl-1, 3, 5-trimethyl-1, 3, 5-trimethyl-1, 3, 5- and 1-10 parts of 2, 3, 3-trifluoropropyl) silane and 1-10 parts of dimethyl dichlorosilane. According to the preparation method, tetramethyl silicate with relatively low reaction activity is used as a raw material to react with silicon tetrachloride to form an intermediate species with moderate activity, and then a linear chain polymer modification layer is pre-formed on the surface by utilizing the difference of reaction rates; a fluorosilane substance added in the coating also can participate in the reaction to form an organic silicon linear polymer with a fluorosilane side chain; in the recombination process of polysiloxane, perfluoro side chains with lower surface energy migrate to the surface of the coating; meanwhile, by adding the dichlorosilane coupling agent and the trichlorosilane coupling agent, the flexibility and hydrophobicity of the coating are improved.

The invention provides a silicon-carbon negative electrode material and a preparation method and application thereof, and belongs to the technical field of lithium ion battery negative electrode materials. The preparation method comprises the following steps: adding silicon tetrachloride and calcium carbide into a carbon tetrachloride solution, uniformly stirring, and transferring into a high-pressure reaction kettle for reaction to obtain a Si-C precursor; adding the obtained Si-coated C precursor into absolute ethyl alcohol and carrying out ball milling treatment; and carrying out suction filtration and drying on the material obtained by ball milling, calcining and carbonizing in inert gas, and cleaning the obtained product to obtain the silicon-carbon negative electrode material. The silicon-carbon negative electrode material prepared by the invention is used for preparing a negative electrode material of a lithium ion battery, has good cycle performance, has relatively high reversible specific capacity and first coulombic efficiency, and is excellent in overall electrochemical performance.

The present invention provides a method for preparing silica based on a liquid-liquid two-phase interface method, comprising the following steps: S1, providing an organic solution and water, wherein the organic solution includes an organic solvent and silicon tetrachloride; the volume ratio of the water to the organic solution is not less than 1 / 50; the molar ratio of the water to the silicon tetrachloride is not less than 4:1; the organic solvent is insoluble or slightly soluble in the water; S2, mixing the water and the organic solution to obtain a first treatment liquid; S3, aging the first treatment liquid to obtain a second treatment liquid; the second treatment liquid comprises an aqueous phase and an organic phase; S4, separating a primary silica product from the second treatment liquid; and calcining the primary silica product to obtain a silica product. The present invention prepares silica nanopowders with a high degree of spheroidization based on silicon tetrachloride and the liquid-liquid two-phase interface method, and the reaction is mild and low-risk.

The utility model relates to a device for preparing pure silane from mixed chlorosilane, which comprises a silicon tetrachloride separation tower, a chlorosilane adsorption column, a silane reaction tower, a silane de-heavy tower, a silane adsorption column and a silane refining tower which are sequentially connected in series, and an upper end outlet of the silicon tetrachloride separation tower is connected with a lower end inlet of the chlorosilane adsorption column; an upper end outlet of the chlorosilane adsorption column is connected with a raw material inlet of the silane reaction tower; an upper end outlet of the silane reaction tower is connected with a raw material inlet of the silane heavy component removal tower; an upper end outlet of the silane heavy component removal tower is connected with a gas phase inlet of the silane adsorption column, and a lower end outlet of the silane heavy component removal tower returns to the middle part of the silane reaction tower; a gas phase outlet of the silane adsorption column is connected with a raw material inlet of the silane refining tower; and an electronic-grade high-purity silane product is obtained at a side line outlet of the silane refining tower. The device is suitable for continuous production of kiloton-grade high-purity silane and continuous production of kiloton-grade high-purity silane, and the energy consumption and the operation cost in the process can be reduced.

The invention relates to a method and a system for preparing trichlorosilane from ferrosilicon, the method comprises the following steps: taking ferrosilicon, silicon tetrachloride and hydrogen as raw materials, fully reacting in a fluidized bed reactor to obtain trichlorosilane and FeSiy alloy, xlt; 40). The system comprises a fluidized bed reactor (200), a cyclone separator (300), a washing tower (400), a gas-liquid separator (500) and a coarse distillation tower (600). Compared with the prior art, the method has the remarkable characteristics that the silazite is used as a silicon source and is low in cost and easy to obtain, the reaction activity of trichlorosilane and FeSiy generated by reaction of the silazite, silicon tetrachloride and hydrogen is high, the utilization rate of silicon elements in the compound is high, no extra catalyst needs to be added in the co-hydrogenation reaction, meanwhile, the byproduct FeSiy alloy is produced, and the production cost is low.

The invention relates to the technical field of asphalt pavement materials, in particular to an RAP-steel slag emulsified asphalt cold recycled mixture volume expansion inhibition method. The method comprises the following steps: firstly, pretreating a selected steel slag sample, and preparing a silicon tetrachloride solution to soak the steel slag; then, the soaked steel slag is taken out and placed in a curing box to be cured, and the pH of the cured steel slag is adjusted; and finally, detecting the expansion rate of the RAP-steel slag emulsified asphalt cold-recycled mixture and the content of free calcium oxide in the RAP-steel slag emulsified asphalt cold-recycled mixture according to specifications, evaluating the volume expansion inhibition effect of the method on the cold-recycled mixture, and based on the further optimization scheme, providing the efficient volume expansion inhibition method for the RAP-steel slag emulsified asphalt cold-recycled mixture. Therefore, the steel slag can be better applied to the asphalt pavement, and the road performance is improved while the solid waste steel slag is fully utilized.

The invention discloses a SiC nanowire in-situ modified ceramic matrix composite connecting fastener and a preparation method thereof, and belongs to the technical field of ceramic matrix composites. The preparation method comprises the following steps: carrying out heat treatment on a fiber preform, carrying out CVD (Chemical Vapor Deposition) or CVI (Chemical Vapor Infiltration) deposition by taking boron trichloride and ammonia gas / ethylene as precursors, dipping in a catalyst solution, drying, and finally carrying out CVI deposition by taking methyltrichlorosilane as a precursor to prepare a composite material preform; the preparation method comprises the following steps: performing CVD (Chemical Vapor Deposition) or CVI (Chemical Vapor Infiltration) deposition on a composite material preform by taking silicon tetrachloride and ammonia gas as precursors, dipping in a precursor solution, drying, performing vacuum cracking treatment, and finally performing CVI deposition and thread processing by taking the silicon tetrachloride and the ammonia gas as the precursors, thereby obtaining the composite material. By means of in-situ growth of the SiC nanowires, rapid densification is achieved while strengthening and toughening are achieved, and the method has the advantages of being short in preparation period, good in product mechanical property, high in connection efficiency and the like.

The invention discloses a cold hydrogenation quench tower energy recovery system and an operation mode, and the system comprises a quench tower, a vaporizer, a first-stage heat exchange system, a second-stage heat exchange system and a circulating water cooler, and layered energy recovery is realized through a three-stage cascade heat exchange structure: a high-temperature liquid-phase material discharged from a quench tower sequentially passes through a second-stage heat exchange system, a first-stage heat exchange system and a circulating water cooler to complete heat exchange, and meanwhile, a heating heat source is provided for silicon tetrachloride and hydrogen. Through the design of multiphase flow enhanced heat transfer, feed gas quality-divided heat exchange and tail liquid recovery, the system significantly improves the energy recovery rate, reduces steam consumption and raw material loss, enhances the operation stability of the system, and is suitable for efficient and energy-saving production of a cold hydrogenation process.

The application discloses an olefin polymerization catalyst and a preparation method thereof, and the olefin polymerization catalyst is used for preparing a polypropylene thermoplastic elastomer, and the olefin polymerization catalyst contains silicon tetrachloride modified silicon dioxide, a transition metal component and a non-transition metal component; the transition metal component is titanium tetrachloride and / or titanium alkoxy, and the non-transition metal component is a magnesium-containing compound. The olefin polymerization catalyst has high initial activity and overall activity, and polypropylene particles with high porosity are obtained. The catalyst can obtain a polypropylene thermoplastic elastomer with high rubber content in the synthesis process of the polypropylene thermoplastic elastomer.

The present invention discloses a method for synthesizing large-sized quartz glass by multi-torch CVD, comprising the following steps: igniting the torches to preheat the furnace; introducing hydrogen, oxygen and silicon tetrachloride into each torch until the temperature and pressure in the furnace are in a stable state; increasing the flow rate of hydrogen, oxygen and silicon tetrachloride introduced into each torch, driving the carrier to rotate and lift to the reference point to start deposition to 90% of the carrier depth; stopping the introduction of silicon tetrachloride into the outer ring torch, and continuing to deposit on the surface of the deposition lump to the target height; stopping the introduction of raw materials, and unloading the lump after natural cooling. The present invention adopts multiple groups of torches arranged in inner rings, middle rings and outer rings, and the torch flames do not interfere with each other, and the furnace temperature distribution can be accurately controlled, thereby improving the uniformity of large-sized synthetic quartz lumps, and at the same time improving the preheating efficiency and deposition efficiency; controlling the raw material supply of different ring torches in the two stages of stable deposition, and realizing uniform and stable deposition of large-sized synthetic quartz lumps.

The utility model provides a liquid removing device externally arranged on a silicon tetrachloride vaporizer, and aims to solve the technical problem that liquid is contained in a medium after silicon tetrachloride is vaporized in the prior art. The liquid removal device comprises: a tank body having an inlet, an outlet and an inspection port; the defoaming net is arranged in the middle of the tank body and located between the inlet and the outlet, and the interior of the tank body is divided into two spaces by the defoaming net; the blind plate covers the inspection opening; wherein the inlet is located at the bottom of the tank body, and the outlet is located above the inlet. The inlet of the tank body is connected with the outlet of the vaporizer, a medium obtained after vaporization of silicon tetrachloride needs to penetrate through the defoaming net, and liquid carried in the medium can be separated through the defoaming net. Besides, the inlet of the tank body is arranged at the bottom of the tank body, so that the separated liquid can fall into the vaporizer again under the influence of gravity for vaporization. According to the technical scheme, the influence on the production quality of polycrystalline silicon in the reduction furnace can be avoided, and the production energy consumption of the polycrystalline silicon is reduced.

A method for cleaning surfaces of a substrate processing chamber includes a) supplying a first gas selected from a group consisting of silicon tetrachloride (SiCl4), carbon tetrachloride (CCl4), a hydrocarbon (CxHy where x and y are integers) and molecular chlorine (Cl2), boron trichloride (BCl3), and thionyl chloride (SOCl2); b) striking plasma in the substrate processing chamber to etch the surfaces of the substrate processing chamber; c) extinguishing the plasma and evacuating the substrate processing chamber; d) supplying a second gas including fluorine species; e) striking plasma in the substrate processing chamber to etch the surfaces of the substrate processing chamber; and f) extinguishing the plasma and evacuating the substrate processing chamber.