171results about "Hydrogen fluoride" patented technology

The invention provides an electronic-grade hydrofluoric acid rectification heat exchange device, and relates to the field of heat exchange devices.The electronic-grade hydrofluoric acid rectification heat exchange device comprises a cold recovery box, the surface of the cold recovery box is provided with a hot backflow pipe and a hot circulation box, a plurality of mass transfer boxes are arranged above the cold recovery box, a plurality of mass transfer bottles are fixedly connected to the interiors of the mass transfer boxes, and the tops of the mass transfer boxes are fixedly connected with a top plate; a plurality of adjusting holes are uniformly formed in the surface of the top plate, adjusting boxes are arranged in the mass transfer boxes, high-corrosion-resistance air bags are symmetrically arranged on the surfaces of the adjusting boxes, adjusting blocks are arranged in the adjusting boxes, rotating pipes are arranged in the mass transfer bottles, and stirring paddles are arranged on the surfaces of the rotating pipes. The efficiency and the stability of the hydrofluoric acid rectification heat exchange device are improved, the adaptability of the device to the production scale and different raw materials is improved, and the energy consumption is reduced.

The invention relates to a phosphorite wet processing method, and belongs to the technical field of chemical engineering. The phosphorite wet processing method comprises the following steps: A, phosphorite acid leaching: carrying out acidolysis leaching on a phosphorite raw material, and carrying out solid-liquid separation to obtain wet-process phosphoric acid; b, removing metal ions from wet-process phosphoric acid; and C, wet-process phosphoric acid defluorination: extracting fluosilicic acid in wet-process phosphoric acid at 10-70 DEG C by adopting a wet-process phosphoric acid defluorination extraction agent, and carrying out phase splitting to obtain defluorinated purified phosphoric acid and an organic phase loaded with fluosilicate. According to the invention, high-value utilization of low-grade phosphorite resources is realized. According to the method, impurities can be fully removed, the loss rate of phosphoric acid is low, the purity of the finally obtained phosphate product reaches 97% or above, the product quality is high, and the requirements of different fields for high-quality phosphate can be met. The method is simple in process, low in energy consumption and low in cost.

The invention discloses a method for recovering valuable metals and fluorine from waste ternary lithium battery black powder. The method comprises the following steps: sulfating roasting: mixing the waste ternary lithium battery black powder with sulfuric acid, curing, and roasting the black powder; the roasted product is subjected to water leaching, and fluorine in water leaching liquid is complexed through boric acid; acidizing and evaporating the water immersion liquid, and collecting hydrofluoric acid; cooling and crystallizing the evaporation mother liquor and collecting boric acid; boric acid is recycled from crystallization mother liquor; precipitating lithium phosphate in the boron extraction raffinate; carrying out acid leaching on the water leaching residues to recover other valuable metals; and anions are extracted from the pickle liquor to realize element circulation. According to the method, through internal circulation of fluorine, boron, sulfur and other elements in the system, resource recycling of fluorine and high-selectivity and high-recovery-rate separation of lithium and other valuable metals can be achieved, and the method has the remarkable advantages of being high in valuable element recycling efficiency, small in environmental pollution and the like and is suitable for complex ion system application scenes.

The invention provides a device for producing anhydrous hydrogen fluoride, which comprises a coarse cooler communicated with a gas outlet of a desulfurizer, a gas outlet of the coarse cooler is communicated with a gas inlet of a primary condenser, and a liquid outlet of the coarse cooler is communicated with a coarse distillation tower; the coarse coolers comprise the first coarse cooler and the second coarse cooler, and the first coarse cooler and the second coarse cooler are connected in series. The anhydrous hydrogen fluoride production device has the beneficial effects that the crude hydrogen fluoride gas is primarily cooled in the production process, so that the content of high-boiling-point substances in crude hydrogen fluoride condensed liquid is reduced, the operation cycle of an anhydrous hydrogen fluoride device production system is prolonged, and the quality of the product anhydrous hydrogen fluoride in a rectification system is improved.

The invention discloses a method and a system for recovering solid residues in titanium dioxide production by a fluorination method. The recovery method comprises the following steps: mixing and reacting solid residues obtained after titanium dioxide is produced by a fluorination method with concentrated sulfuric acid with the concentration of 95-100wt% at the temperature of 25 DEG C or above, so as to obtain ferric sulfate and hydrogen fluoride. According to the method for recycling the solid residues in the titanium dioxide produced through the fluorination method, FeF3 in the solid residues can be converted into Fe2 (SO4) 3 and HF to be recycled, waste is turned into wealth, H2SO4 used in the recycling method is wide in source, the requirement for technological conditions is low, pollution to the environment is small, and the method is suitable for industrial production. And clean production can be realized while the process energy consumption is reduced.

The present invention relates to the technical field of waste resource utilization, and in particular to a method for recycling perfluorocarbon waste. Perfluorocarbon waste is pre-treated, and then mixed with auxiliary materials at a mass ratio of 1:1-5 for perfluorocarbon waste: auxiliary materials to obtain a solid material to be treated; the solid material to be treated is mixed with cement raw material, and sintered at 1400-1500°C to obtain a clinker as a cement raw material; wherein the physical form of the perfluorocarbon waste is liquid or solid; and the auxiliary materials are selected from at least one of coal powder, quicklime powder, charcoal powder, slaked lime powder and cement clinker powder. The recycling method of the present invention can convert perfluorocarbon waste into primary minerals such as calcium fluoride as components in clinker, with low recycling cost and high efficiency.

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.

Disclosed in the present application is a hydrofluoric acid regeneration method for photovoltaic waste acid. The method comprises the following steps: S1, light component removal, involving: introducing a liquid containing hydrofluoric acid to be treated into a light component removal tower, wherein the tower bottom temperature of the light component removal tower is 100-105°C, and the tower top temperature is 70-80°C, subjecting the liquid to be treated to a light component removal treatment by means of the light component removal tower, discharging the water vapor, which is generated by means of light component removal, via the tower top of the light component removal tower, discharging the generated light component removal liquid, which is generated by means of light component removal, via the tower bottom of the light component removal tower, and introducing same into a first rectification tower; and S2, rectification, involving: the tower bottom temperature of the first rectification tower being 110-115°C, and the tower top temperature being 98-105°C, rectifying the generated light component removal liquid by means of the first rectification tower, discharging HF and water vapor, which are generated by means of rectification, via the tower top of the first rectification tower, condensing same to form hydrofluoric acid, and discharging the distillate, which is generated by means of rectification, via the tower bottom of the first rectification tower. By means of the present application, hydrofluoric acid in the hydrofluoric acid waste liquid can be recycled, and compared with the prior art, the situation where fluorine resources are wasted is effectively avoided.

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 invention provides a calcium fluoride forming method and a calcium fluoride forming body, and belongs to the technical field of calcium fluoride preparation.The calcium fluoride forming method comprises the following steps that calcium fluoride raw powder is subjected to dispersion pretreatment, and pretreated powder is obtained; mixing the pretreated powder with hydroxypropyl methyl cellulose, a binder and water, and performing extrusion molding to obtain a preform; and drying and roasting the preformed body to obtain the calcium fluoride formed body. The calcium fluoride forming method provided by the invention does not need high temperature and high pressure, and is mild in process condition, low in cost, short in reaction time, low in energy consumption and high in production efficiency; the calcium fluoride forming body prepared by the method has a larger specific surface area, provides more action sites for water absorption in HCl and HF gases, does not need to be modified, is safer and more environment-friendly, and has higher mechanical strength.

The invention belongs to the technical field of chemical engineering, and particularly relates to a preparation method of electronic-grade hydrofluoric acid. The method comprises the following steps: 1) arranging an electrolytic cell, filling a cathode region with a fluorine raw material solution, filling an anode region with an acidic raw material solution, and separating the anode region from the cathode region by an anion exchange membrane; 2) electrifying the electrolytic cell for electrolysis, and collecting gas in an anode region to obtain mixed feed gas; and (3) sequentially filtering, mixing, absorbing, cooling and recovering the mixed raw material gas to obtain the electronic-grade hydrofluoric acid. According to the method, synthesis and preliminary separation of hydrogen fluoride are achieved in one step through an electrolytic method, high-purity hydrogen fluoride can be effectively and stably obtained, ultra-high-purity electronic-grade hydrofluoric acid is rapidly prepared through aftertreatment, and the preparation process is relatively low in energy consumption, safe and environmentally friendly.

There is provided a method for producing iodine heptafluoride in which iodine heptafluoride having a low content of iodine gas can be produced with high yield. The method for producing iodine heptafluoride includes: a preparation step of preparing a liquid mixture containing iodine pentafluoride and hydrogen fluoride in which a content of the hydrogen fluoride is 0.1% by mass or more and 20% by mass or less with respect to a content of the iodine pentafluoride; a vaporization step of obtaining raw material mixed gas containing iodine pentafluoride gas, hydrogen fluoride gas, and fluorine gas by mixing fluorine gas with the liquid mixture to vaporize the liquid mixture; and a reaction step of producing iodine heptafluoride by causing the raw material mixed gas to react in a presence of a catalyst.

The invention provides novel azeotrope-like compositions and separation processes utilizing the same. An azeotrope-like composition comprising 1,2-difluoroethylene (HFO-1132) and hydrogen fluoride. An azeotrope-like composition comprising 1,1,2-trifluoroethylene (HFO-1123) and hydrogen fluoride. A separation process for a composition comprising at least one member selected from the group consisting of trans-1,2-difluoroethylene (HFO-1132(E)), cis-1,2-difluoroethylene (HFO-1132(Z)), and 1,1,2-trifluoroethylene (HFO-1123) and hydrogen fluoride.

Provided is a method for producing iodine heptafluoride with which it is possible to produce iodine heptafluoride having a low iodine gas content at a high yield. This method for producing iodine heptafluoride comprises: a preparation step for preparing a liquid mixture containing iodine pentafluoride and hydrogen fluoride, the hydrogen fluoride content being 0.1-20 mass% of the iodine pentafluoride content; a gasification step in which fluorine gas is mixed into the liquid mixture and the liquid mixture is gasified to obtain a raw material mixed gas containing iodine pentafluoride gas, hydrogen fluoride gas, and fluorine gas; and a reaction step in which the raw material mixed gas is reacted in the presence of a catalyst to produce iodine heptafluoride.

The invention provides a hydrogen fluoride production system and method, and belongs to the technical field of hydrogen fluoride production, the hydrogen fluoride production system comprises a reaction unit, a purification unit and a rectification unit which are arranged in sequence, and the rectification unit comprises a rectification tower, a first cooler, a second cooler and a cold crude acid tank; the first cooler is provided with a first cooling medium channel and a first working medium channel, and an inlet of the first working medium channel communicates with an outlet of the purification unit; the second cooler is provided with a second cooling medium channel and a second working medium channel, an inlet of the second working medium channel is communicated with an outlet of the first working medium channel, an outlet of the first working medium channel is communicated with an inlet of the second working medium channel, and an outlet of the first cooling medium channel is communicated with the rectifying tower; according to the invention, the liquid hydrogen fluoride is stored in the cold crude acid tank, so that the liquid hydrogen fluoride cools the gaseous hydrogen fluoride in the first cooler, a coolant does not need to be purchased or supplemented, and the production cost is reduced.

Provided is a fluorine gas production method, which makes it possible to re-use a byproduct hydrogen fluoride, which is a byproduct produced during the production of a fluoride, i.e., a desired component, by reacting a raw material compound with a fluorine gas to fluorinate the raw material compound, as a raw material for the production of a fluorine gas by an electrolysis method. The fluorine gas production method comprises: a fluorination step of producing a reaction mixture comprising a main product fluoride, which is a desired component produced by fluorinating a raw material compound, and a byproduct hydrogen fluoride, which is produced as a byproduct; a separation step of separating the reaction mixture to produce a main product component containing the main product fluoride and a byproduct component containing the byproduct hydrogen fluoride; a purification step of purifying the byproduct component to produce such a recycled hydrogen fluoride component that the concentration of an organic substance contained in the byproduct component is decreased and the concentration of the byproduct hydrogen fluoride is increased; an electrolysis step of carrying out an electrolysis procedure using the recycled hydrogen fluoride component as at least a portion of an electrolyte solution to produce a fluorine gas; and an introduction step of introducing the fluorine gas produced in the electrolysis step into a reaction field for fluorination in the fluorination step.

Hydrofluoric acid-specific recovery system for the refining of industrial raw materials, comprising: a wastewater collection channel which receives hydrofluoric acid-containing wastewater, and an activated carbon filter system which filters out the organic substances and the oxidizing substances from the hydrofluoric acid-containing wastewater and then produces a first wastewater, and a capacitor-based deionization system which transports the ions of the first wastewater to an electrode of opposite charge and then produces a low-concentration fluorine wastewater, and also causes the ions to detach from the electrode and then produces a high-concentration fluorine wastewater, and a low-concentration collection channel which serves to receive the low-concentration fluorine wastewater, at least one filtration unit which filters the low-concentration fluorine wastewater and then produces recovery water for internal plant use, and a high-concentration collection channel.which serves to receive the highly concentrated fluorinated wastewater, and a reaction plant which produces a cryolite through a reaction of an added aluminum-containing sodium compound with the highly concentrated fluorinated wastewater.

The invention relates to the technical field of AHF purification, and provides an AHF purification method which comprises the following steps: step 1, pretreatment; step 2, multi-stage filtration; step 3, ultrasonic-assisted adsorption; 4, membrane separation and purification; step 5, freezing crystallization; 6, rectifying and refining; and 7, tail gas treatment. According to the AHF purification method, through a series of fine operations such as multi-stage filtration, ultrasonic-assisted adsorption, membrane separation purification, freezing crystallization and rectification refining, the purity of AHF is remarkably improved to 99.99% or above, and the requirements of high-purity products are met. The impurity removal effect is enhanced through multi-stage filtration and ultrasonic-assisted adsorption, the purification efficiency is improved through membrane separation purification and freezing crystallization, and the separation effect is further improved through combination of rectification refining and a novel tower plate structure and filler. Tail gas treatment realizes environment-friendly emission through multi-stage absorption and catalytic reaction, and product stability and consistency are ensured through quality detection and adjustment.

The invention discloses a method for recovering mixed acid waste liquid containing hydrofluoric acid, comprising reacting a raw material with a sodium salt or a potassium salt, and then filtering to obtain a filtrate; the raw material is a mixed acid waste liquid containing hydrofluoric acid; the filtrate is sent to a diffusion dialysis device for treatment, the diffusion dialysis device includes a homogeneous anion exchange membrane; the recovered liquid obtained by the treatment of the diffusion dialysis device is sent to a membrane separation device, the membrane material of the membrane separation device is an acid-resistant metal ion removal membrane, and the recovered mixed acid is obtained on the permeation side of the membrane separation device. The invention can effectively remove impurities and metal ions in low-concentration waste acid solutions, so that the products meet the electronic grade reuse standard, improve the resource recovery rate, and have a simple process flow and low energy consumption, which is suitable for industrial promotion and application.

The application discloses a vulcanization system and method for silicone rubber based on SF6 waste gas plasma reduction treatment. In the system, a mixed gas chamber, a discharge system, a vulcanization system, a separation gas chamber and a collection gas bottle are sequentially connected by gas paths, the separation gas chamber is connected with the mixed gas chamber through a dilution gas chamber, flow meters and electromagnetic valves are arranged between the mixed gas chamber and the discharge system, between the mixed gas chamber and the dilution gas chamber, and between the separation gas chamber and the dilution gas chamber, and an ultraviolet light source is used for providing light for the discharge system and the vulcanization system, wherein a catalyst is arranged in the discharge system, SF6 waste gas, hydrogen and dilution gas can be introduced into the mixed gas chamber. The application can efficiently utilize S elements in SF6 waste gas, degrades SF6 through catalysis, realizes vulcanization treatment of silicone rubber base material in real time by taking S as a vulcanizing agent while depositing S in the form of an element, finally converts S elements in SF6 waste gas into vulcanized silicone rubber in the form of vulcanization crosslinking, and achieves the purpose of resource utilization of S elements in SF6 waste gas.

An apparatus for treating a fluid including an organofluorine compound, the apparatus including: a vessel that contains a liquid with a fluoride bonding agent; a combustion chamber in fluid communication with the vessel via an outlet submerged in the liquid; an inlet configured to introduce the fluid into the combustion chamber; and a flame source configured to produce a flame in the combustion chamber to at least partially break down the organofluorine compound to form a gaseous combustion product bearing fluoride, wherein the gaseous combustion product passes from the outlet of the combustion chamber through the liquid so that the fluoride in the gaseous combustion product is at least partially bound by the fluoride bonding agent.

The present invention relates to a comprehensive treatment method for the process tail gas of lithium hexafluorophosphate, comprising the following steps: 1) absorbing the tail gas containing phosphorus fluoride and phosphorus chloride with water to obtain a mixed acid containing hydrogen chloride, hydrogen fluoride and phosphoric acid; 2) electrolyzing the mixed acid obtained in step 1) until the hydrogen chloride in the mixed acid is completely electrolyzed to obtain a solution; 3) heating the solution obtained in step 2) to cause the water and hydrofluoric acid to escape by heat, and then obtaining hydrofluoric acid after cooling. Through electrolysis and phosphorus removal treatment, fluorine, chlorine and phosphorus in the process tail gas of lithium hexafluorophosphate are fully separated, and hydrofluoric acid and chlorine are respectively prepared. The chlorine can be recycled for the preparation of phosphorus pentachloride in the production of lithium hexafluorophosphate, realizing the recycling of chlorine. At the same time, industrial-grade hydrofluoric acid can be obtained, and the added value of the product is high.

The invention provides a method for purifying hydrogen chloride in fluorine-containing hydrogen chloride tail gas. The method comprises the following steps: enabling tail gas containing trace phosphorus pentafluoride, hydrogen fluoride and hydrogen chloride to pass through an adsorption column, and carrying out in-situ reaction on water generated after the hydrogen fluoride is chemically adsorbed by an adsorption column filling material and phosphorus pentafluoride to generate phosphorus oxyfluoride; gas at an outlet of the adsorption column passes through a microporous gas distributor, the gas reacts with a metal organic reagent, and then high-purity hydrogen chloride gas is obtained after hydrogen fluoride is separated through rectification. According to the method, high-purity hydrogen chloride can be prepared, and emission of pollutant-containing gas is reduced.

The invention relates to an advanced treatment method and system for fluorine-containing wastewater in semiconductor / photovoltaic industry. The treatment method comprises the following steps: pH adjustment: adding sodium hydroxide into pretreated fluorine-containing wastewater or fluorine-containing wastewater without silicon, and adjusting the pH value to 9.5-10.2, so that fluorine ions exist in the form of sodium fluoride; performing ceramic ultrafiltration membrane CUF treatment and reverse osmosis membrane RO treatment to obtain RO produced water and sodium fluoride concentrated water; deep purification: the RO produced water passes through a deep fluorine removal resin adsorption unit, so that the concentration of fluorine ions in the water is reduced to 1t; 1 ppm, so as to obtain recycled produced water; resourceful treatment: introducing the sodium fluoride concentrated water into a bipolar membrane electrodialysis system, and converting the sodium fluoride concentrated water into hydrofluoric acid and a sodium hydroxide solution; and refining and recycling.

The invention relates to the technical field of hydrogen fluoride preparation processes, and provides a method for extracting hydrogen fluoride from fluorine-containing byproduct sulfuric acid, which comprises the following steps: (1) preheating the fluorine-containing byproduct sulfuric acid; (2) distilling the preheated fluorine-containing byproduct sulfuric acid to obtain a gas-phase component and a liquid-phase component; (3) condensing the gas-phase component to obtain crude hydrogen fluoride; wherein the fluorine-containing byproduct sulfuric acid comprises sulfuric acid and hydrofluoric acid, the concentration of the sulfuric acid is C, the distillation temperature is T, C and T meet the following formula: # imgabs0 #, and eta is more than or equal to 0.95 and less than or equal to 2.

This invention belongs to the field of chemical technology, and particularly relates to a method for preparing electronic-grade hydrofluoric acid. The method includes: 1) setting up an electrolytic cell, with the cathode region filled with a fluorine-based raw material solution and the anode region filled with an acidic raw material solution, the anode and cathode regions separated by an anion exchange membrane; 2) electrolyzing the electrolytic cell and collecting the gas from the anode region to obtain a mixed raw material gas; 3) sequentially passing the mixed raw material gas through filtration, mixing absorption, and cooling recovery to obtain electronic-grade hydrofluoric acid. This invention achieves the synthesis and preliminary separation of hydrogen fluoride in one step via electrolysis, effectively and stably obtaining high-purity hydrogen fluoride. Post-processing rapidly achieves the preparation of ultra-high-purity electronic-grade hydrofluoric acid, and the preparation process is relatively energy-efficient, safe, and environmentally friendly.

The present application relates to a stainless steel pickling waste mixed acid treatment system and a method for recovering nitric acid and hydrofluoric acid, the stainless steel pickling waste mixed acid treatment system comprising a waste acid storage tank, an electrolytic cell, an air extraction device, a spraying device, a filtering device, a cathode acid storage tank and an anode acid storage tank, wherein the electrolytic cell is provided with a cation membrane, separating the electrolytic cell into a cathode chamber and an anode chamber, the cathode chamber being connected to the cathode acid storage tank through the corresponding air extraction device and spraying device, for guiding the hydrogen fluoride gas volatilized from the cathode chamber into the cathode acid storage tank, the anode chamber being connected to the anode acid storage tank through the corresponding air extraction device and spraying device, for guiding the nitric acid gas volatilized from the anode chamber into the anode acid storage tank, the cathode chamber and the filtering device being connected into a circulating loop, for circulating and filtering the cathode liquid to remove the precipitate in the cathode liquid, the filtering device also being connected to the cathode acid storage tank, and the anode chamber being connected to the anode acid storage tank. The above-mentioned waste mixed acid treatment system can realize the recovery of nitric acid and hydrofluoric acid in the waste mixed acid.

The invention discloses a hydrogen fluoride recovery device, and relates to the technical field of chemical equipment. The hydrogen fluoride recovery device comprises a flash tank, a heater, a circulation driving part, a negative pressure generator and a first washing assembly, the flash tank is provided with a first liquid outlet, a liquid return port and a first exhaust port, and the heater is connected with the first liquid outlet and the liquid return port and used for heating a medium flowing through the heater. The circulation driving part is connected with the heater in series and used for driving a medium in the flash tank to flow to the heater, the negative pressure generator is connected with the first exhaust port and used for extracting gas in the flash tank so as to generate negative pressure in the flash tank, the first washing assembly comprises a first washing tower, the first washing tower is provided with a first inlet, and the first inlet is connected with the negative pressure generator; the first washing tower is used for washing gas discharged by the negative pressure generator. According to the hydrogen fluoride recovery device, the working temperature can be reduced, and the operation reliability can be improved.

A method to make HF including the steps of mixing a first solution of hexafluorosilicic acid a second solution of a polyamine wherein an FSA-PA complex is formed, and degrading at least a portion of the FSA-PA complex to yield HF.

This invention discloses a method for preparing electronic-grade hydrofluoric acid for semiconductors, comprising the following steps: a. Liquid anhydrous hydrogen fluoride raw material is preheated and vaporized. After vaporization, the hydrogen fluoride passes sequentially through a primary sodium fluoride adsorption column and a secondary sodium fluoride adsorption column, causing some sodium fluoride to be converted into sodium hydrogen fluoride. The unadsorbed tail gas is absorbed by sodium hydroxide alkaline solution; b. The sodium fluoride adsorption column undergoes a first-stage heating process to desorb free water and silicon tetrafluoride gas, and is held at this temperature for 1 hour. The desorbed gas enters the tail gas absorption; c. The sodium fluoride adsorption column is further heated for a second-stage desorption of hydrogen fluoride, and held at this temperature for 1 hour, causing sodium hydrogen fluoride to decompose into high-temperature hydrogen fluoride gas; d. The high-temperature hydrogen fluoride gas from step c is absorbed and prepared with ultrapure water to form crude hydrofluoric acid, which is then filtered through a membrane to obtain electronic-grade hydrofluoric acid for semiconductors. This invention features a short production process, low energy consumption, and recyclable adsorption materials. Compared with traditional processes, it has lower production costs, better quality, and significant economic benefits.