100 results about "Silicon tetrafluoride" patented technology

The invention relates to the technical field of purification equipment, and discloses high-purity silicon tetrafluoride separation and purification equipment which comprises a filter cartridge and a separation tank and further comprises a molecular sieve filled in the filter cartridge, a hollow pipe is fixedly connected to the center of the inner bottom surface of the filter cartridge, a locking rod is inserted into the hollow pipe in a penetrating mode, and a cover plate is attached to the top end of the hollow pipe. The top end of the locking rod is in threaded connection with a rotary knob, the outer surface of the filter cylinder is sleeved with an upper lantern ring and a lower lantern ring, a vertical plate is fixedly connected between the upper lantern ring and the lower lantern ring, and a scraper is installed on the outer surface of the vertical plate. Through combination of the filter cartridge and the molecular sieve filled in the filter cartridge, dust, moisture, hydrogen fluoride and other impurities in a silicon tetrafluoride gas phase substance can be effectively removed, and when the molecular sieve needs to be replaced, the sealing cover is opened, the knob is screwed to be separated from the locking rod, and the cover plate is taken up, so that the top end of the filter cartridge is exposed to facilitate replacement of the molecular sieve.

The invention belongs to the field of inorganic chemical industry, and particularly relates to a method and a system for efficiently utilizing a phosphate fertilizer byproduct, the method comprises the following steps: carrying out acidolysis on fluosilicic acid with the concentration of more than or equal to 45% wt and concentrated sulfuric acid to generate a mixed solution of silicon tetrafluoride gas and fluorosulfonic acid; the mass ratio of the fluosilicic acid to the concentrated sulfuric acid is controlled to be 1: (4-15); pyrolyzing the obtained fluorosulfonic acid to generate dilute sulphuric acid, hydrogen fluoride and water vapor, forming 98% concentrated sulphuric acid from part of dilute sulphuric acid and fuming sulphuric acid, drying hydrogen fluoride to obtain crude hydrogen fluoride gas, and condensing and rectifying to obtain anhydrous hydrogen fluoride; the rest dilute sulphuric acid is partially compounded and then returned for acidolysis, and the rest dilute sulphuric acid is used for producing white carbon black and flows back to a wet-process phosphoric acid system; and circularly absorbing the obtained silicon tetrafluoride gas by using secondary concentrated fluosilicic acid to obtain fluosilicic acid with the mass concentration of more than or equal to 45%, recycling the fluosilicic acid for acidolysis reaction, and modifying the concentrated by-product silicon dioxide to obtain the high-activity white carbon black. The problems of energy consumption and cost are solved, and efficient circulation and poly-generation of fluorine and silicon resources are achieved in the whole process.

The present invention relates to the technical field of hydrogen fluoride preparation, and particularly to a method for separating a mixed solution containing hydrogen fluoride and sulfuric acid. The separation method includes: A) Concentrated fluorosilicic acid and concentrated sulfuric acid react in a reaction device to generate silicon tetrafluoride gas and a sulfuric acid solution containing hydrogen fluoride; B) The first part of the sulfuric acid solution containing hydrogen fluoride is subjected to two-stage separation to obtain hydrogen fluoride gas; the second part of the sulfuric acid solution containing hydrogen fluoride is heated and recycled to the reaction device. The present invention adopts two-stage separation; another path of the sulfuric acid solution containing hydrogen fluoride led out after the main reaction enters the reaction device again after being heated, with relatively low energy consumption. Therefore, the separation method provided by the present invention separates hydrogen fluoride from the sulfuric acid solution with relatively low energy consumption and can reduce fluorine loss.

The utility model discloses a fluorine chemical industry silicon tetrafluoride pollutant waste gas recovery and treatment device which comprises a water washing recovery tower, an alkali washing reaction tower, a biological deodorization filter tank, a centrifugal fan, a first integrated circulating water tank, a second integrated circulating water tank and a third integrated circulating water tank. According to the utility model, the fluorine chemical waste gas emission meets the requirements of Technical Specification for Treatment and Disposal of Fluorine-Containing Waste Gas GB / T33056-2016 and Zhejiang Province that the odor concentration of industrial and mining enterprises is organized to be not more than 1000 (dimensionless), meanwhile, the recycling of silicon tetrafluoride resources is realized, and the technology of the utility model is worthy of popularization and application.

The present disclosure relates to a method or producing silicon tetrafluoride from fluorosilicic acid. In one implementation, a first stream comprising fluorosilicic acid and a second stream comprising sulfuric acid are reacted in a pressure regulator to produce an outgoing liquid stream comprising silicon tetrafluoride. The outgoing liquid is then fed into at least one separator which outputs at least one gas stream containing silicon tetrafluoride and at least one liquid stream. The at least one gas stream is fed into at least one additional separator which separates the at least one gas stream into at least one stream of purified silicon tetrafluoride gas. In some implementations, the at least one liquid stream is recycled back into the at least one separator.

The invention provides a silicon tetrafluoride purification method and a preparation method of modified activated carbon for deep purification of silicon tetrafluoride, and belongs to the technical field of silicon tetrafluoride purification. The silicon tetrafluoride purification method comprises the following steps that silicon tetrafluoride raw material gas is sequentially adsorbed with activated carbon and a molecular sieve, and primary purified silicon tetrafluoride is obtained; introducing ammonia gas into the primarily purified silicon tetrafluoride for reaction, carrying out gas-solid separation, and removing impurities from the obtained gas component by using modified activated carbon to obtain secondarily purified silicon tetrafluoride; a modification method of the modified activated carbon comprises the following steps: reacting activated carbon with fluorine-containing gas at 80-100 DEG C; and rectifying the secondarily purified silicon tetrafluoride to obtain the high-purity silicon tetrafluoride. The purity of the purified silicon tetrafluoride gas reaches 6N grade or above, the time for the modified activated carbon to reach adsorption saturation is long, the service cycle is long, and the production cost can be effectively reduced.

The application relates to a method and a preparation system for preparing hydrogen fluoride from fluosilicic acid, which comprises a reaction kettle, a hydrogen fluoride absorption tower, a condenser and a silicon tetrafluoride absorption tower which are sequentially communicated; a gas outlet of the reaction kettle is communicated with a gas inlet of the hydrogen fluoride absorption tower, and a gas outlet of the hydrogen fluoride absorption tower is communicated with a gas inlet of the condenser; the generated fluorosulfonic acid in the reaction kettle is introduced into a stripping tower, fluorosulfonic acid generated in a side reaction is re-generated into hydrogen fluoride, the generation of intermediate products is reduced, the process route of the application is free of waste residues and waste gas, and fluosilicic acid is effectively utilized.

The application provides a method for preparing a silicon negative electrode material by using SiF4 as a raw material, and belongs to the field of battery negative electrode materials. The method for preparing the silicon negative electrode material by using SiF4 as the raw material can simultaneously obtain microcrystalline silicon and amorphous silicon by using silicon tetrafluoride as a silicon source, controlling the placement position of a substrate, the radio frequency power of an inductive radio frequency coil and the temperature of a reaction zone; and the silicon material capable of meeting the use of a lithium ion battery negative electrode can be further obtained by controlling the proportion of silicon tetrafluoride, hydrogen and argon. The method provided by the application can simultaneously obtain microcrystalline silicon and amorphous silicon, and the lithium ion battery prepared from the microcrystalline silicon and the amorphous silicon has good cycle life and coulomb efficiency, and can be used as a negative electrode material.

The invention discloses a method for preparing hydrogen fluoride and co-producing fumed silica from low-concentration fluosilicic acid, which belongs to the technical field of inorganic chemical industry and comprises the following steps: concentrating low-concentration fluosilicic acid under reduced pressure; mixing concentrated sulfuric acid with system circulating sulfuric acid, reacting with concentrated fluosilicic acid, and performing gas-liquid separation to obtain mixed liquid of silicon tetrafluoride gas, hydrogen fluoride and sulfuric acid; and washing the separated silicon tetrafluoride gas and / or silicon tetrafluoride gas generated by a wet-process phosphoric acid process with concentrated sulfuric acid, reacting with water vapor, hydrogen and oxygen, and dedusting to obtain the fumed silica. The method has the advantages of simple process flow, low production cost, high product quality, low three-waste output and the like. Besides, low-grade and low-concentration fluosilicic acid is used as a raw material, fluorine and silicon elements are efficiently separated, high-value fumed silica and high-quality hydrogen fluoride are prepared, and good social and economic values are embodied; and cyclic utilization of byproducts such as sulfuric acid reduces environmental pollution and three-waste treatment pressure, and has good environmental protection benefits.

The invention discloses a system and method for preparing high-purity silicon dioxide, and the system comprises a Venturi injection pump which is used for mixing silicon tetrafluoride gas with water to form jet flow; the swirler is connected with the venturi injection pump, and the swirler is connected with the venturi injection pump; the jet flow enters the swirler and then is subjected to separation treatment, and underflow and upper-layer overflow are formed; and the separation device is connected with the cyclone and is used for separating the silicon dioxide from the underflow and the upper overflow to obtain silicon dioxide particles. The method for preparing the high-purity silicon dioxide has the advantages of being simple in process, high in product purity, environmentally friendly, low in production cost, convenient for industrial production and the like, and has high economic benefits and social benefits.

A degassing tower for preparing hydrogen fluoride relates to the field of hydrogen fluoride preparation, and is characterized in that a cylindrical mesh cage (2) is arranged in the middle of an inner cavity of a tower body (1), an auxiliary assembly (5) is arranged below the cylindrical mesh cage (2), a spraying assembly (3) is arranged above the cylindrical mesh cage (2) in the inner cavity of the tower body (1), and a driving assembly (4) is arranged at the top of the spraying assembly (3); according to the invention, the cylindrical mesh cage which can float and is used for more sufficient contact between the to-be-treated gas and the gathered liquid is arranged in the middle of the tower body, and the spraying assembly used for assisting adsorption of substances except hydrogen fluoride is arranged above the cylindrical mesh cage; the top of the spraying assembly is provided with the driving assembly which is used for rotating the spraying assembly to enable the spraying area of the spraying assembly to be more uniform and providing driving force for the auxiliary assembly, so that non-condensable gases such as sulfur dioxide and silicon tetrafluoride in a hydrogen fluoride gas mixture are removed; and the hydrogen fluoride gas is condensed to obtain a qualified anhydrous hydrogen fluoride product.

The invention belongs to the technical field of aluminum smelting solid hazardous waste recycling, and particularly relates to a recycling method of aluminum oxide-rich complex electrolyte hazardous waste. According to the method, the complex aluminum electrolyte hazardous waste, aluminum salt and silicon-containing oxide are mixed and then subjected to segmented roasting-leaching treatment, fluorine in the electrolyte is converted into aluminum fluoride firstly and then converted into silicon tetrafluoride gas, separation of fluorine and aluminum and separation of gas and solid are achieved, and sodium and lithium elements are converted into soluble salt and further separated and recycled. According to the process, collaborative recovery and high-value utilization of various valuable elements in the complex aluminum electrolyte hazardous waste are achieved. The whole technological process is environment-friendly, toxic and harmful gas emission is avoided, secondary solid waste residues are not generated, the method has the advantages of being simple in process, high in recovery rate, high in product additional value and the like, and a feasible technical scheme is provided for resource utilization of the aluminum electrolysis solid waste.

The present disclosure relates to a system for the production of silicon tetrafluoride. In one implementation, a reactor is configured to at least convert fluorosilicic acid (FSA) into silicon tetrafluoride at a reaction zone. A separator receives the products of the reactor and is configured to separate the products into at least a gaseous stream and a liquid stream. At least one additional reactor is configured receive the at least a liquid stream of the reactor and configured to yield a refined product at a reaction zone. At least one additional separator is configured to separate the refined product into at least a gaseous stream and a liquid stream at a separating zone. Finally, a washer is configured to receive and wash the gaseous stream of the product and the gaseous stream of the refined product at a washing zone, wherein the washer yields a purified silicon tetrafluoride product.

The present disclosure relates to a method for concentrating fluorosilicic acid from a first liquid stream comprising fluorosilicic acid. In one implementation, the solution comprising fluorosilicic acid and a gaseous stream comprising silicon tetrafluoride is introduced into a first reactor. The first reactor reacts to form the products and separates the products into at least one intermediate gas stream and at least one intermediate liquid stream. The at least one intermediate liquid stream is then introduced into at least one additional reactor. At least one product of the reactor is then separated using the at least one additional reactor. The at least one additional reactor separates the at least one product into at least a final liquid stream comprising fluorosilicic acid. The fluorosilicic acid mass percentage in the at least one final liquid stream is greater than the fluorosilicic acid mass percentage in the at least one first liquid stream.

The application discloses a method and system for preparing ammonium bifluoride from hydrofluoric acid waste liquid, which comprises the following steps: (1) adding the hydrofluoric acid waste liquid into an electrolytic cell, transporting the electrolytic cell to a first reaction kettle after electrodepositing treatment, adding silicon dioxide, then stirring and reacting, and returning the generated silicon tetrafluoride and hydrofluoric acid into a spray tower to react and then return to the first reaction kettle, and then adding ammonia water to perform neutralization reaction; (2) filtering the solid-liquid mixture I, evaporating and drying the obtained filtrate I to obtain an ammonium nitrate product, and returning the obtained filter cake I to a second reaction kettle, adding ammonia water to adjust the pH value, and then stirring and reacting; (3) filtering the solid-liquid mixture II, returning the obtained filter cake II to the first reaction kettle for reuse, transporting the obtained filtrate II to a reactor, adding hydrofluoric acid to perform reaction, and then performing evaporation and drying treatment to obtain an ammonium bifluoride product. The method is simple in process, low in energy consumption, convenient to operate and convenient for industrialized production and application.

The application provides a method for removing parasitic silicon carbide, which comprises using silane and an oxygen-free cleaning gas containing hydrogen and hydrogen fluoride gas, keeping the cleaning temperature in a cleaning chamber not lower than 1300 DEG C, and removing the parasitic silicon carbide under a cleaning pressure not lower than 100 mbar, so as to improve the cleaning rate. The hydrogen gas plays a dilution role on the hydrogen fluoride gas, and meanwhile, the cleaning efficiency is considered, so as to prevent over-etching. The silicon species generated by the decomposition of silane can generate gaseous silicon tetrafluoride with fluorine, and is adsorbed on the surface of exposed graphite basal body after cleaning, so as to reduce the significant damage of the hydrogen fluoride gas to the surface of exposed graphite basal body after cleaning. In the later cleaning stage, the silane is switched to propane, so as to improve the silicon-rich atmosphere formed in the cleaning chamber due to the introduction of silane, reduce or avoid the problem that the silicon species adsorbed on the surface of the graphite basal body is difficult to be taken away by the flow field of the purge gas, and make the surface of the epitaxial wafer appear obvious cluster phenomenon.

A system includes a remote plasma source, a process chamber, an exhaust line connected to the process chamber, a recirculation line connected to the process chamber, and a sensor to measure a concentration of a byproduct, such as silicon tetrafluoride, in an exhaust of the processing chamber. The system also includes a controller to release the exhaust of the processing chamber through the exhaust line or the recirculation line based on the measured concentration of the byproduct in exhaust of the process chamber.

This invention relates to a silicon tetrafluoride gas absorption device for the production of hydrofluoric acid from fluorosilicic acid. The device includes a housing, within which is an absorption cylinder extending horizontally along its axis. One end of the absorption cylinder is fixedly connected to an inlet pipe, and the other end is rotatably mounted to a liquid inlet pipe via a bearing. The housing is equipped with a drive motor for rotating the inlet pipe and an inlet structure for introducing silicon tetrafluoride gas into the inlet pipe. The end of the liquid inlet pipe away from the absorption cylinder extends out of the housing and is sealed and fixedly connected to it. A suction pipe is located inside the liquid inlet pipe, with its inner end extending to the lower side of the absorption cylinder. The outer wall of the absorption cylinder has several filter holes, each hinged with a sealing cap. A torsion spring on the hinge shaft of the sealing cap keeps it sealed to the filter holes. The housing also includes a gas supply pipe and a gas extraction pipe. Compared to existing technologies, this invention offers better absorption of silicon tetrafluoride and better separation of silica hydrates.

The present disclosure provides a method for comprehensively recycling and repairing and regenerating the cathode material of waste batteries in an integrated manner. The repair and regeneration method includes the following steps: (1) After discharging the waste batteries, pyrolysis separation is carried out to obtain cathode material powder; (2) Lithium supplementation and calcination treatment are carried out on the cathode material powder, and the waste gas is subjected to condensation recovery, acid gas removal and organic gas collection treatment; (3) The collected organic gas is mixed with silicon tetrafluoride to obtain a mixed gas, and the mixed gas is used to carry out plasma coating treatment on the powder obtained by lithium supplementation and calcination to obtain silicon carbide-coated cathode material. The obtained waste gas is recovered by using SiO2, and the obtained silicon tetrafluoride gas is recycled after drying treatment. The present disclosure not only utilizes the organic gas generated by the decomposition of the electrolyte, but also restores the performance of the lithium iron phosphate cathode material, and only silicon dioxide needs to be consumed while fixing the tail gas during the whole reaction process, with low cost.

The invention relates to the technical field of fluoride preparation, in particular to a preparation method of high-purity silicon tetrafluoride, which comprises the following steps: step 1, preparing a fluosilicic acid solution and magnesium oxide, and carrying out mixed reaction on the fluosilicic acid solution and the magnesium oxide; 2, reacting to generate a magnesium fluosilicate solution, and crystallizing the solution; step 3, carrying out dehydration treatment on the crystallized crystal; step 4, calcining the dehydrated crystal; and 5, purifying the silicon tetrafluoride gas obtained by calcining, and collecting the purified silicon tetrafluoride gas. The preparation method comprises the following steps: mixing a fluosilicic acid solution and magnesium oxide for reaction to generate a magnesium fluosilicate solution, crystallizing the solution, dehydrating crystallized crystals, removing attached water and crystal water, centrifugally separating to obtain dry magnesium fluosilicate crystals, and properly calcining the magnesium fluosilicate crystals to obtain the magnesium fluosilicate. And the silicon tetrafluoride gas is purified and then collected, so that high-purity silicon tetrafluoride is obtained.

The invention discloses a preparation method of high-purity silane suitable for a small experimental device, which comprises the following steps: sequentially connecting and arranging a main reactor, a second reactor, a condenser, a silane buffer tank, a booster pump and a silane steel cylinder, and injecting hydrogen, nitrogen and silicon tetrafluoride materials into the main reactor after passing through the same mass flow controller; then the material enters a second reactor through a gas phase outlet pipeline at the top of the main reactor, a gas phase outlet at the top of the second reactor is connected with an inlet at the bottom of a condenser, an outlet of the condenser is connected with a silane buffer tank, and an outlet pipeline is arranged at the top of the silane buffer tank; materials enter the booster pump through the outlet pipeline, are pressurized in the booster pump and then are fed into the silane steel cylinder to be stored, so that the complexity of the reaction device is simplified, the energy consumption is reduced, and the problems of huge device size, complex process conditions and the like are solved.

The application discloses a method for preparing white carbon black and ammonium fluoride from silicon tetrafluoride, wherein the silicon tetrafluoride gas enters an ammoniation reactor through the middle part, the carrier gas and the ammonia gas enter the ammoniation reactor through the bottom part, solid particles SiO2 and NH4F are generated, the carrier gas flows out from the top outlet of the ammoniation reactor and enters a separator, solid slurry is rapidly formed after being washed in the spray at the top inlet of the separator, and then the solid slurry is settled into the separator; inert solvents are added into the separator, and SiO2 and NH4F are separated by using the density difference. The application uses the SiF4 gas obtained by decomposing fluorosilicic acid or the by-product silicon tetrafluoride gas of phosphate fertilizer as raw materials to continuously produce high-quality white carbon black and ammonium fluoride, and the method is continuous, stable, simple, and has a long operation period, and effectively overcomes the defects of the existing intermittent process technology.

The invention provides a method for removing silicon tetrafluoride in boron trifluoride by adopting a chemical method, and belongs to the technical field of purification and impurity removal. The preparation method comprises the following steps: introducing a boron trifluoride raw material into anisole for complex reaction to obtain complex product feed liquid; the molar ratio of the anisole to the boron trifluoride raw material is 1: (0.3-0.8); performing exhaust treatment on the complexing product feed liquid to obtain exhaust feed liquid; the temperature of the exhaust treatment is 30-40 DEG C; the exhaust feed liquid is subjected to cracking treatment, and purified boron trifluoride is obtained; the final temperature of the cracking treatment is 100-120 DEG C. The method disclosed by the invention is excellent in desilicication effect, can meet the requirement of electronic grade boron trifluoride on the content of silicon tetrafluoride, is high in product yield and low in energy consumption, and greatly reduces the cost.

This invention relates to a chemical equipment, specifically a silicon tetrafluoride concentrator. The technical solution includes a main gas inlet pipe, characterized in that at least one set of spray cylinder sections are connected in series within the main gas inlet pipe. Each spray cylinder section includes vertical and horizontal sections. The vertical section has gas inlets and outlets at different heights. The gas inlet of the vertical section is connected to the main gas inlet pipe, and the gas outlet of the vertical section is connected to the inlet of the horizontal section. The top of the horizontal section has multiple spray mounting ports, into which spray pipes are inserted. The lower end of each spray pipe is connected to a nozzle, and the upper end is connected to a main liquid pipeline. This invention features simple structure, low equipment height, low investment and operating costs, sufficient gas-liquid contact, good concentration effect, corrosion and wear resistance, convenient maintenance, and stable and reliable operation.

The invention relates to the technical field of electronic special gas purification, in particular to a separation device and method for removing carbon dioxide and hydrogen sulfide in silicon tetrafluoride mixed gas through a two-stage membrane. The two-stage membrane of the separation membrane element of the CHA molecular membrane and the polyimide membrane is adopted, and the rectifying tower is coupled, so that the use of chemical substances such as sulfuric acid and an adsorbent can be avoided on the basis of obtaining the high-purity silicon tetrafluoride product gas, and the production cost and the post-treatment cost are reduced.

This invention discloses a method for efficiently preparing aluminum fluoride from aluminum ash, comprising the following steps: Aluminum ash is ground, preheated, and then oxidized for denitrification. Silicon chloride is used to chlorinate the aluminum, iron, and magnesium in the oxidized aluminum ash into aluminum chloride, ferric chloride, and magnesium chloride. High-purity aluminum chloride is obtained through multi-stage condensation and purification. The aluminum chloride is then gasified, preheated, and reacted with silicon tetrafluoride to produce aluminum fluoride and silicon chloride. The silicon chloride is recycled for use in the chlorination process. This invention significantly improves the oxidative denitrification efficiency of aluminum ash through grinding and activation. The chlorination process uses silicon chloride as the chlorinating agent, eliminating the need for carbon addition. The chlorination products are easily separated, and the operation is simple. Silicon tetrafluoride is used to fluorinate aluminum chloride to prepare aluminum fluoride. The byproduct silicon chloride can be recycled within the system, effectively reducing production costs. Simultaneously, the system has high energy utilization, enabling the harmless treatment of aluminum ash and the large-scale, efficient preparation of aluminum fluoride, resulting in significant economic and social benefits.

The invention discloses a method for preparing a silicon isotope and a boron isotope. The method comprises the following steps: purifying boron powder through a pretreatment process to obtain high-purity boron powder; vacuumizing the reactor to-0.08 MPa to-0.09 MPa, then introducing inert gas to replace air in the reactor, and carrying out reduction reaction on the high-purity boron powder and the high-purity silicon tetrafluoride gas rich in silicon-28 in the reactor to obtain a crude silicon-28 isotope product; the method comprises the following steps: removing impurities from a crude silicon-28 isotope product through plasma zone melting to obtain a silicon-28 isotope product, removing excessive silicon tetrafluoride from generated boron trifluoride gas through a low-temperature rectification process, preparing boron-10 and boron-11 isotopes, and returning the excessive silicon tetrafluoride to a system for recycling. The one-step coupling preparation technology of the silicon and boron isotopes is developed, the silicon-28 isotopic, the boron-10 isotope and the boron-11 isotope are prepared at the same time, efficient directional conversion of the silicon and boron isotopes is achieved, the production cost is further reduced, and the economic benefits of the process are remarkable.

The invention discloses a process and a device for preparing hydrogen fluoride by a fluosilicic acid complexing method. The process comprises the following steps: mixing a fluosilicic acid solution, a complexing solution and a cross-linking agent to generate a complexing reaction to obtain a first mixed material containing a metastable state complex; raising the temperature of the first mixed material to be stable, so as to obtain a second mixed material containing a solid-phase steady-state complex; and carrying out solid-liquid separation on the second mixed material, drying the solid, and carrying out thermal decomposition to obtain hydrogen fluoride gas, silicon tetrafluoride gas and a liquid material. The device comprises complex reaction equipment, cross-linking reaction equipment, first solid-liquid separation equipment, a drying machine and complex decomposition equipment. The complexing agent can be recycled for a long period and has the advantages of being high in separation efficiency, small in fluosilicic acid loss, high in hydrogen fluoride yield, low in material consumption and energy consumption and the like, and on the basis that a hydrogen fluoride product reaches superior product indexes, the fluosilicic acid complexing rate reaches 98% or above, the complex decomposition rate reaches 95% or above, and the total hydrogen fluoride yield reaches 90% or above.

The application discloses a closed loop process for synchronously increasing the value of silicon and fluorine components in silicon tetrafluoride, and belongs to the technical field of fluorine-containing silicon byproduct resource utilization. The steps are as follows: 1) mixing anhydrous alcohol with triethylamine, and introducing silicon tetrafluoride gas at 0-30 DEG C to generate alkyl orthosilicate and triethylamine monohydrofluoride; 2) distilling the reaction liquid to recover alcohol, performing vacuum rectification to obtain alkyl orthosilicate product, and separating to obtain triethylamine monohydrofluoride; 3) adding triethylamine monohydrofluoride into water, and performing heating reflux reaction with inorganic alkali or basic oxide to separate to obtain triethylamine crude product and fluorinated metal salt; 4) after dehydration rectification, the triethylamine crude product is recycled to step 1) with recovered alcohol; and the fluorinated metal salt is post-treated to obtain high-purity fluorinated metal salt. The process has low reaction temperature, high alkyl orthosilicate yield, recyclable triethylamine, all fluorine solidified into high-value-added products, no three-waste emissions, and can be continuously industrialized.

A system includes a remote plasma source, a process chamber, an exhaust line connected to the process chamber, a recirculation line connected to the process chamber, and a sensor to measure a concentration of a byproduct, such as silicon tetrafluoride, in an exhaust of the processing chamber. The system also includes a controller to release the exhaust of the processing chamber through the exhaust line or the recirculation line based on the measured concentration of the byproduct in exhaust of the process chamber.