611 results about "Fluorhydric Acid" patented technology

The invention belongs to the technical field of photovoltaic wet etching, and particularly relates to a low-concentration hydrofluoric acid composite etching solution and a preparation method and an etching process thereof, and the low-concentration hydrofluoric acid composite etching solution comprises the following components in percentage by mass: 5%-10% of hydrofluoric acid, 2%-5% of an etching additive and the balance of water; wherein the etching additive comprises the following components in percentage by mass: 8%-25% of a strong oxidant, 2%-5% of an etching accelerant, 0.5%-2% of an interface modification and mass transfer accelerant, 0.1%-3% of a product control and stabilizer, 0.1%-2% of an equipment compatible corrosion inhibitor and the balance of water; the strong oxidant is used for oxidizing silicon nitride to form a silicon oxynitride transition layer, the etching accelerant is used for providing HF molecules and HF2-ions, and the product control and stabilizing agent is used for complexing SiF62-ions generated by etching.

The invention discloses a fluoride-free flotation-microbiological leaching-multistage magnetic separation synergistic tailing purification process, which takes mine tailings as raw materials and is realized by the following steps: 1, fluoride-free flotation desliming and impurity removal: replacing hydrofluoric acid with a novel anion collector (fatty acid derivative), and preferentially removing mica and feldspar under the condition that the pH is 2.5-3.5; 2, removing iron and aluminum by microbiological leaching: leaching for 48 hours at the temperature of 35 DEG C by utilizing an acidophilus bacillus ferroxidans bacterial solution, and dissolving Fe2O3 and Al2O3 in a wrapped state; 3, high-gradient magnetic separation refining: removing magnetic minerals through 1.2 T strong magnetic separation, and then separating weak magnetic impurities through 0.8 T weak magnetic separation; the indexes of the final product are as follows: the purity of SiO2 is greater than or equal to 99.9%, the whiteness is greater than or equal to 94% (ISO standard), the content of Fe2O3 is less than or equal to 80ppm, Al2O3 is less than or equal to 1200ppm, and the requirements of electronic grade (IOTA-4 standard) quartz powder are met.

The invention discloses a preparation method and application of a high-nitrogen-doped ordered mesoporous carbon supported copper catalyst, and belongs to the technical field of catalyst preparation. The preparation method comprises the following steps: by taking cane sugar and a copper-nitrogen complex as raw materials, SBA-15 as a template agent and sulfuric acid as a catalyst, carrying out equivalent-volume impregnation, low-temperature heat treatment, 800-900 DEG C high-temperature carbonization and nitric acid / hydrofluoric acid demolding to prepare pyrrole nitrogen enriched or pyridine nitrogen enriched high-nitrogen doped ordered mesoporous carbon with a large specific surface area; the preparation method comprises the following steps: loading a copper species on high-nitrogen-doped ordered mesoporous carbon by adopting an equivalent-volume impregnation method, and reducing at 350-400 DEG C to prepare the high-nitrogen-doped ordered mesoporous carbon loaded copper catalyst. The prepared catalyst is high in nitrogen content, large in specific surface area, high in pyridine nitrogen or pyrrole nitrogen enrichment degree and uniform in copper particle dispersion and shows efficient catalytic performance in methanol oxidative carbonylation reaction, and the highest methanol conversion rate is 9.3%.

The utility model discloses an electronic-grade hydrofluoric acid production system, industrial hydrofluoric acid is input into the system to obtain high-purity electronic-grade hydrofluoric acid, and the system comprises a graphite evaporator, a rectifying tower and a condenser, the graphite evaporator is provided with a feeding pipeline and a condensed water outlet, and the feeding pipeline is used for inputting industrial hydrofluoric acid into the graphite evaporator; a steam pipeline is further arranged on the graphite evaporator, the other end of the steam pipeline is connected with the rectifying tower, the steam pipeline is used for conveying gas heated by the graphite evaporator into the rectifying tower, and the rectifying tower is used for rectifying and separating hydrofluoric acid gas produced by the graphite evaporator; industrial hydrofluoric acid is added into the graphite evaporator to be heated to obtain hydrofluoric acid, then the hydrofluoric acid is fed into the rectifying tower with a certain height to be distilled, backflow is conducted in proportion, the product quality meets the requirement, and continuous production can be achieved through combination of the graphite evaporator and the rectifying tower; liquid hydrofluoric acid is used as a raw material, high risk of anhydrous hydrogen fluoride gas is avoided, and safety of the system is improved.

The invention discloses a fracturing imbibition system for refracturing a low-permeability tight oil reservoir and a preparation method of the fracturing imbibition system, and belongs to the technical field of fracturing fluids, the fracturing imbibition system comprises: an acid liquid base fluid: hydrochloric acid, hydrofluoric acid, EDTMPS and deionized water; an amphoteric betaine viscoelastic surfactant; biologically modifying the nanoparticles; a Gemini cationic surface active agent; a corrosion inhibitor; and an organic silicon defoaming agent and a fluorocarbon discharge aiding agent. According to the fracturing imbibition system, through the integrated design of the multifunctional surfactant, the problems that a traditional acid fracturing fluid is insufficient in silicate mineral dissolving capacity, high-temperature viscosity is attenuated, and corrosion inhibitor dependence is caused are solved.

The invention relates to a high-temperature acidolysis reaction defluorination method, and belongs to the technical field of phosphorus chemical resource recycling. The technical problem to be solved by the invention is to provide a high-temperature acidolysis reaction defluorination method which is simple to operate and high in defluorination rate. According to the method, phosphorite powder / white fertilizer is subjected to high-temperature acidolysis, fluoride in the phosphorite powder / white fertilizer reacts with strong acid, fluorine is separated from a reaction system in a gas form, and hydrofluoric acid is obtained through condensation. The method is simple, is simple and convenient to operate, and is easy to realize technologized large-scale production. Meanwhile, due to the destructive effect of the strong acid on the lattice structure of the phosphorus-calcium compound, citrate-soluble phosphorus can be converted into soluble phosphate, subsequent phosphorus recovery is facilitated, comprehensive utilization of phosphorite and elimination of white fertilizer output are achieved, meanwhile, the problems of material accumulation and resource waste of enterprises are solved, and the method conforms to the circular economy concept of green development.

The invention belongs to the technical field of geological sample analysis and detection, and particularly discloses a method for measuring the amount of each element of lithium ore in a closed acid-soluble system, and the method comprises the following steps: pretreating the lithium ore; the pretreated lithium ore is weighed and put into a closed sample dissolving device, hydrofluoric acid and purified nitric acid are sequentially added, and the closed sample dissolving device is closed; carrying out heat preservation on the closed sample dissolving device twice to obtain a test solution; and measuring the test solution by using an inductively coupled plasma mass spectrometer to obtain a working curve, and calculating the content of the analysis element in the sample solution by using the working curve. The method for determining the amount of each element in the lithium ore by adopting the closed acid-soluble system has the characteristics of simplicity in operation, high efficiency and good stability, realizes simultaneous determination of the amount of lithium, rubidium, cesium, beryllium, strontium, niobium, tantalum, zirconium, hafnium and rare earth elements in the large-batch lithium ore, and further provides a reference for determination of main trace elements in the lithium ore.

The invention discloses a low-cost nano porous silicon-carbon composite material based on a solid waste silicon source as well as a preparation method and application thereof. The preparation method comprises the following steps: taking a solid raw material containing silicon dioxide as a silicon source; carrying out wet ball milling on the pretreated raw materials; mixing the ball-milled material with magnesium powder, aluminum chloride and lithium chloride; carrying out heating reduction reaction on the mixed material; sequentially performing hydrochloric acid pickling and hydrofluoric acid pickling on the reduction product, and then washing to be neutral; mixing the washed silicon particles with a carbon precursor containing nitrogen and sulfur, coating by adopting a spray coating method, and then carrying out carbonization treatment; the carbon precursor containing nitrogen and sulfur is composed of asphalt and thiourea; the carbonization temperature is 750-850 DEG C, the carbonization time is 1-2 hours, and the heating procedure comprises a desolventizing section, an asphalt decomposition section and a carbonization section. The preparation method is low in raw material cost, low in energy consumption, environment-friendly and excellent in product comprehensive performance, and has wide application prospects in the fields of power batteries, energy storage, catalysis and the like.

The invention relates to the technical field of etching solutions, and particularly discloses an etching solution for inhibiting etching of metallic titanium and application of the etching solution. The etching solution contains hydrofluoric acid, ammonium fluoride, an additive 1 and an additive 2; wherein the additive 1 is a fluorine capture type inhibitor, and the additive 2 is a surface adsorption type organic protective agent. The etching solution can effectively inhibit the corrosion of a titanium layer while keeping the high etching rate of silicon oxide, obviously improves the etching selection ratio of silicon oxide to titanium, has lower surface tension and higher uniformity, and is suitable for a wet etching scene with a complex structure. The additive 1 captures free fluorine ions through complexation or precipitation, the activity of the fluorine ions is reduced, and therefore the chemical attack on the titanium surface is reduced; and the additive 2 can form a transient adsorption protective film on the titanium surface to further delay the dissolution of titanium. The synergistic effect of the two additives can effectively inhibit titanium corrosion and maintain high etching efficiency.

This invention discloses a method for dissolving NiCrPSi nickel alloy samples for ICP-OES detection, comprising the following steps: mixing the NiCrPSi nickel alloy sample to be tested with hydrochloric acid aqueous solution, concentrated nitric acid, and hydrofluoric acid aqueous solution, digesting at 120-140℃ for 1.5-2.5h, and then evaporating the solution to dryness at 220-260℃; then adding nitric acid aqueous solution and heating until the solid is completely dissolved, and then diluting with water to obtain the NiCrPSi nickel alloy test solution. The dissolution method of this invention can completely dissolve NiCrPSi nickel alloy powder without elemental loss, providing an accurate sample solution for ICP-OES detection; and it eliminates the need for specialized equipment such as microwave digesters or electrothermal digesters, as well as special reagents such as perchloric acid and tartaric acid, using only conventional acid reagents and general experimental equipment, thus reducing costs, simplifying operation, and enhancing versatility.

This invention relates to the field of inorganic non-metallic material purification technology, and particularly to a purification method for deep removal of difficult-to-remove impurities from quartz sand. The technical solution includes the following steps: quartz ore is electrically melted, cooled, and then crushed to obtain amorphous fused quartz sand; the amorphous fused quartz sand is magnetically separated, then calcined, and subsequently quenched in ultrapure water; the water-quenched quartz sand is pretreated with dilute hydrochloric acid solution, dried, and then pretreated to obtain pretreated quartz sand; the pretreated quartz sand is then heated and acid-leached with a mixed acid solution that does not contain hydrofluoric acid. This invention, under green conditions that completely eliminate hydrofluoric acid, utilizes the amorphous fused quartz method to eliminate the locking effect of the quartz lattice on impurities, achieving efficient and deep removal of difficult-to-remove impurities such as aluminum, lithium, titanium, calcium, and magnesium, stably obtaining ultra-high purity quartz materials with a purity of 5N or higher, and the process conditions are mild and compatible with existing industrial equipment.

The invention discloses a surface etching method for revealing dislocation defects of tellurium indium lead single crystals, and relates to a method for revealing crystal defects. The invention aims to provide a surface etching method capable of accurately exposing crystal defects. The method comprises the following steps: firstly, carrying out directional cutting, multi-stage mechanical polishing and chemical mechanical polishing on a PIT single crystal to obtain a smooth and damage-free surface; and reacting iodine with concentrated nitric acid to generate iodic acid as a main oxidant, adding hydrofluoric acid for activation, diluting with an acetic acid-water mixed solution, and etching the crystal at a low temperature of 10 + / -1 DEG C under ultrasonic assistance. According to the method, the regular triangular conical etching pit can be formed on the PIT single crystal (001) surface, the depth is 100-300 nm, the pit bottom points to the [001] direction, and the dislocation defect is clearly revealed. The method has the advantages of clear etching morphology, high sensitivity, high reliability and simplicity and convenience in operation, and can be applied to the fields of PIT single crystal quality evaluation, defect analysis and growth process optimization.

The invention relates to an improved process for the manufacture of a fluorinated organic compound, wherein the process comprises a fluorination reaction of an organic precursor compound having at least one chlorine substituent and / or at least one double bond, and said organic precursor compound is reacted in liquid phase in HF (hydrogen fluoride) serving as solvent and fluorinating agent in the presence of a fluorinating catalyst, and wherein the fluorination reaction is performed in liquid phase in a SiC block chemical reactor, and wherein the reaction mixture is withdrawn from SiC block chemical reactor, and wherein the process comprises optionally isolating and / or purifying the targeted fluorinated organic compound.

The application discloses a mesoporous carbon preparation process with recyclable silicon source and mesoporous carbon with small pore size and large specific surface area. The mesoporous carbon preparation process comprises the following steps: preparing a silicon template: reacting a fluosilicic acid solution with calcium carbonate, and separating calcium fluoride precipitate and silica sol; the pH of the silica sol is 2-5; the concentration of silicon dioxide in the silica sol is 1-8 wt%; preparing a precursor: dissolving a carbon source and an organic acid in the silica sol, drying, grinding, and carbonizing in an inert atmosphere to obtain a C / Si precursor; the organic acid comprises at least one of oxalic acid, tannic acid, acetic acid and citric acid; removing the silicon template and recycling the silicon source: treating the C / Si precursor with hydrofluoric acid, and performing solid-liquid separation to obtain mesoporous carbon and a fluosilicic acid solution, wherein the fluosilicic acid solution is used for preparing the silicon template. The specific surface area of the mesoporous carbon is greater than 800 m 2 / g, and the pore size is less than 6 nm.

This invention belongs to the field of two-dimensional material preparation technology, and provides an MXene material and its preparation method. The preparation method of the MXene material includes: mixing a MAX phase precursor to be etched with an organic halide reagent and a morphology modifier, performing a solvothermal etching reaction, and after the reaction, washing and drying the resulting product to obtain the MXene material; wherein the organic halide reagent is triethylamine trihydrofluoride, triethylamine hydrochloride, or dichloroethylamine hydrochloride, and the morphology modifier is ethylene glycol, dimethyl sulfoxide, or cyclohexane. The method of this invention can effectively control the microstructure and pore structure of the MXene material.

The invention discloses a method for producing anhydrous hydrofluoric acid from photovoltaic fluorine-containing waste materials. The waste materials are fluorine-containing solid press filter residues or filter cake biscuits obtained through solid-liquid separation after photovoltaic fluorine-containing waste liquid treatment. The method comprises the following steps: drying, crushing and screening the waste until the waste is matched with the fluorite powder in particle size, returning the oversize product to the crushing, closed-loop granulating and homogenizing; continuously metering and uniformly mixing the homogenized waste and fluorite powder according to a mass ratio of 20: 1 to obtain a mixed fluorine-containing raw material, and continuously feeding the mixed fluorine-containing raw material into a rotary reaction furnace; fuming sulfuric acid and concentrated sulfuric acid are mixed into mixed acid, the mixed acid is continuously added into a reaction furnace, the mixed acid reacts at the temperature of 300-350 DEG C to generate a fluorine-containing gas phase, and reaction heat is indirectly provided by circulation of high-temperature gas in a jacket of the reaction furnace; the crude product gas enters a degassing tower to remove SO2 and SiF4 after being subjected to dust removal, washing, cooling, condensation, rectification, deacidification and dehydration, and an anhydrous hydrofluoric acid product is obtained. According to the method, waste recycling is achieved, and fluorite consumption and waste disposal amount are reduced.

The application discloses a continuous production process and equipment for a trifluoromethylbenzene tower, and belongs to the field of organic fluorine chemistry. The production process comprises the following steps: S1: continuously feeding trichloromethylbenzene and hydrogen fluoride into a tower reactor connected with a heat exchanger circulating cooling system in a reverse direction, so that a three-stage continuous fluorination reaction occurs in the tower reactor to obtain crude trifluoromethylbenzene, and unreacted hydrogen fluoride is separated into liquid at the top of the tower and then flows back into the tower reactor; S2: the crude trifluoromethylbenzene obtained in the reaction is subjected to nitrogen bubbling in a bubble tower, and then is continuously distilled in a rectifying tower to obtain finished trifluoromethylbenzene; and S3: byproduct hydrogen chloride generated in the fluorination reaction is introduced into a hydrochloric acid tank to obtain hydrochloric acid, and the content of hydrofluoric acid in the hydrochloric acid is less than 1000 ppm. The method can greatly improve the utilization rate of raw material hydrogen fluoride, improve the purity of byproduct hydrochloric acid, reduce the generation amount of waste acid, avoid the sharp change of pressure in the reaction process, and realize large-scale, continuous, stable and safe production of trifluoromethylbenzene.

This invention discloses a method for determining the arsenic content in ores, belonging to the field of ore element detection technology, comprising the following steps: (1) weighing the ore sample, adding hydrochloric acid-nitric acid mixed acid for acid hydrolysis, then adding hydrofluoric acid and perchloric acid for auxiliary digestion, evaporating to near dryness, and dissolving the residue with hydrochloric acid; (2) adding a thiourea-ascorbic acid-citric acid mixed reducing masking agent to reduce and mask interfering ions; (3) using an atomic fluorescence spectrometer to determine the fluorescence intensity of arsenic in the sample solution, and calculating the arsenic content according to the standard curve. This method achieves accurate and stable determination of arsenic in various ores such as phosphate rock and iron ore by optimizing sample pretreatment conditions, improving the reduction system and matrix interference suppression strategy.

The invention relates to the field of chemical equipment, and discloses a production device and method of 1, 1-difluoroethane. The production apparatus comprises: a reactor; a reflux tower and a first condenser, a feed inlet and a liquid phase outlet of the reflux tower are connected with the reactor, a gas phase outlet of the reflux tower is connected with the first condenser, and a gas phase outlet of the first condenser is connected with the reactor; the separation tower is connected with a liquid phase outlet of the first condenser, a liquid phase outlet of the separation tower is connected with the reactor, a gas phase outlet of the separation tower is connected with the second condenser, a gas phase outlet of the second condenser is connected with the reactor, and a liquid phase outlet of the second condenser is connected with the separation tower; and the post-treatment system is connected with the liquid phase extraction port of the separation tower. The production device can be used for separating and recycling hydrogen fluoride, reducing the content of hydrogen fluoride in the product, eliminating the consumption of fresh water and alkali liquor caused by a water alkali washing process, avoiding the generation of aqueous hydrofluoric acid with low additional value, and eliminating a heavy component removal tower.

The invention discloses a silicon carbide epitaxial wafer cleaning method. The silicon carbide epitaxial wafer cleaning method sequentially comprises the following steps: S1, pre-cleaning with ultrapure water and high-pressure N2 water-gas two-fluid; s2, transferring into an acid liquor tank filled with a mixed solution of hydrochloric acid, hydrofluoric acid and hydrogen peroxide for treatment; s3, transferring into No.1 alkali liquor filled with a mixed solution of ammonia water and hydrogen peroxide for treatment; s4, transferring into No.2 alkali liquor containing a mixed solution of ammonia water, hydrogen peroxide and an ampholytic surfactant for treatment, wherein the concentration of the ammonia water in the mixed solution in the step is lower than that of the ammonia water in the mixed solution in the step S3; s5, slowly pulling and drying with warm water; and S6, infrared heating and drying. Through cooperation of the steps, the cleaning effect of the silicon carbide epitaxial wafer is improved, and the number of residual metal ions and particles on the surface of the epitaxial wafer is effectively reduced.

The invention discloses a flotation collecting agent formula based on quartz, a preparation method and an extraction method. The flotation collecting agent formula comprises a cation collecting agent and an anion collecting agent which are used in cooperation. Wherein the cation collecting agent is prepared from the following components in parts by weight: 10 to 40 parts of dodecyl amine, 10 to 40 parts of coconut oil alkylamine, 2 to 8 parts of dodecyl trimethyl ammonium chloride, 1 to 4 parts of a nonionic surfactant, 2 to 8 parts of ethanol and 5 to 10 parts of hydrochloric acid; the anion collecting agent comprises a sulfonate surfactant; the use of hydrofluoric acid is greatly reduced, fluorine pollution is reduced, the anionic collector and the cationic collector are compounded to play a synergistic role, implementation can be carried out under the weak acid condition, agent preparation and process control are simple and convenient, the agent dispersity is good, temperature and ore property fluctuation can be adapted, the flotation selectivity and recovery rate of quartz and feldspar can be remarkably improved, and the flotation efficiency is improved. The resource utilization value of the tailings is improved.

The invention discloses a preparation method of high-purity Nb2O5, belongs to the field of preparation of Nb2O5, and solves the problem of low purity of Nb2O5 prepared by the existing method. The preparation method comprises the steps that a metal niobium ingot with the purity larger than or equal to 99.999% is adopted, and vacuum drying is conducted after surface peeling, dilute nitric acid ultrasonic cleaning and high-purity water flushing are conducted; the pretreated niobium ingot is subjected to a hydrogenation reaction in a pure hydrogen atmosphere, niobium hydride is generated and then crushed, and niobium hydride powder is obtained; carrying out dehydrogenation treatment on the niobium hydride powder under a high vacuum condition; dissolving the metal niobium powder with electronic-grade hydrofluoric acid, and filtering to obtain fluorine niobic acid filtrate; performing multi-stage counter-current extraction and reverse extraction on the fluobiobic acid filtrate by adopting an extracting agent to obtain fluobiobic acid reverse extraction liquid; introducing high-purity ammonia gas into the fluobiobic acid strip liquor, and precipitating to generate niobium hydroxide; ageing, filtering and washing with high-purity water for multiple times to obtain a niobium hydroxide filter cake; and calcining the niobium hydroxide filter cake in a high-purity oxygen atmosphere in stages to obtain niobium pentoxide. The niobium pentoxide prepared by the method disclosed by the invention is high in purity.

Disclosed is a method with which it is possible to relatively easily manufacture a member having a recessed structure that is close to a vertical structure. This method for manufacturing a member having a recessed structure includes: (1) installing a catalyst material (130) on a part of a first surface (112) of a workpiece (110), wherein the first surface (112) contains silicon (Si), and oxygen (O) and / or nitrogen (N), and the catalyst material (130) contains an organic molecule; and (2) exposing the workpiece (110) to a fluorine-containing gas at 80°C or higher. After the step (2), a recessed structure (150) is formed in a part of the first surface (112). With respect to the organic molecule, the value of the distance dHF between the hydrogen atom and the fluorine atom in a hydrogen fluoride molecule when an adsorption structure is assumed is 0.965 (Å) or more as calculated using the 6-31 + G(d) basis function and the B3LYP correlation-exchange functional.

The invention discloses a method for growing titanic acid / titanium dioxide nanoparticles on a titanium carbide Mxene sheet layer, and relates to a method for growing titanic acid / titanium dioxide nanoparticles on the surface of a titanium carbide Mxene sheet layer structure. The method comprises the following steps: firstly, etching titanium aluminum carbide at room temperature by adopting hydrofluoric acid to obtain a layered titanium carbide Mxene material, then dispersing the layered titanium carbide Mxene material in hydrogen peroxide with the mass percent concentration of 20-30%, simultaneously adding 0.6 ml of 65% nitric acid, and reacting for 24-72 hours at the temperature of 20-80 DEG C, so that titanic acid nanoparticles can grow on the surface of a titanium carbide Mxene lamellar structure; and subsequently carrying out heat treatment in an air atmosphere at 200-500 DEG C, and converting the titanic acid into anatase titanium dioxide. The preparation temperature is low without high pressure; the nanoparticles keep a lamellar structure aggregation state, and are expected to be applied to the fields of adsorption, photocatalysis and the like.

The utility model discloses a kind of hydrogen fluoride acid-resistant storage tanks, including upper head, barrel and lower head sequentially arranged from top to bottom, upper head, barrel and lower head are cut after by hydrogen fluoride acid-resistant composite material, and assembled into storage tank.The hydrogen fluoride acid-resistant composite material sequentially includes inner lining layer, anti-permeation layer, strength layer, outer protective layer and anti-aging layer from inside to outside, and adjacent layer and layer are bonded fixed.In inner lining layer, anti-permeation layer of structure layer inside, reinforcing fiber is polyester fiber, in outer protective layer of structure layer outside, reinforcing fiber is also polyester fiber, polyester fiber can resist HF corrosion, structure layer is arranged between anti-permeation layer and outer protective layer, and glass fiber reinforced material cannot be subjected to medium corrosion by using.The storage tank structure of the utility model guarantees the corrosion resistance of storage tank while guaranteeing the strength of tank body.

The utility model relates to a kind of rectifying column of low-grade fluorite preparation anhydrous hydrogen fluoride.The rectifying column of low-grade fluorite preparation anhydrous hydrogen fluoride includes tower body, tower body is equipped with tray, tray includes plate body, plate body upper side is equipped with overflow plate, plate body between two overflow plates is equipped with steam passage, plate body is equipped with downcomer, steam passage is equipped with steam pipe, plate body upper side is equipped with cover cap covering steam pipe upper side, cover cap is equipped with steam outlet, the inboard of cover cap is equipped with adjusting ring, plate body is equipped with the guide rod moving up and down, the upper end of guide rod is fixedly connected with adjusting ring, the lower end of guide rod extends plate body lower side and is fixedly connected with push plate, and reset spring is equipped between guide rod and plate body lower side face.The utility model can increase the steam area of steam outlet when steam pressure rises, thereby relieving steam pressure rise, avoid the evaporation temperature rise caused by steam pressure rise, and increase the indirect contact between steam and hydrofluoric acid, improve rectification efficiency.

The application belongs to the technical field of oil exploitation, and particularly relates to an acid liquid for acid treatment of an oil layer and a preparation method thereof. The preparation method is as follows: the specific steps of the preparation method are as follows: in a reactor, piperazine-1,4-diethyl sulfonate monosodium salt, ethanol and bromoalkane are added, heated to reflux, and during the reaction, sodium hydroxide solution is used to maintain pH 7-8; 1-bromo-6-(trimethylammonium) hexyl bromide is added, heated to reflux, and during the reaction, sodium hydroxide solution is used to maintain pH 8-9; vacuum distillation is performed to obtain a viscous solid, cyclohexane recrystallization is performed to obtain a solid, and the solid is dried at 90 DEG C overnight to obtain corrosion-inhibiting acid; hydrochloric acid, hydrofluoric acid, hydroxyethylidene diphosphonic acid, corrosion-inhibiting acid and water are added to the reactor, stirred uniformly, and the acid liquid is obtained. The acid liquid has the advantages of low corrosion rate and long acidification time.

The invention discloses a synthesis process of tungsten hexafluoride, and relates to the technical field of special gas synthesis. The process comprises the following steps: mixing ammonium fluoride and hydrofluoric acid to prepare an activation solution, carrying out ultrasonic activation treatment on tungsten powder to obtain pretreated tungsten powder, and reacting the pretreated tungsten powder with fluorine gas at a certain temperature and pressure to prepare a liquefied crude product tungsten hexafluoride; the preparation method comprises the following steps: by taking aluminum sec-butoxide and the like as raw materials, carrying out sol-gel and ethanol supercritical drying and calcining to prepare highly porous activated aluminum oxide; gasifying the crude tungsten hexafluoride, adsorbing with activated aluminum oxide, and rectifying to obtain purified tungsten hexafluoride liquid; and finally, dissolving in liquid sulfur dioxide, treating under illumination with the wavelength of 395nm, and carrying out distillation separation to obtain high-purity tungsten hexafluoride. According to the method, the activation pretreatment is combined with multi-stage purification, so that the purity and the synthesis efficiency of tungsten hexafluoride are remarkably improved.

The invention provides a preparation method of lithium hexafluorophosphate with low fluorine emission, and relates to the technical field of preparation of lithium hexafluorophosphate, the preparation method comprises the following steps: by taking anhydrous lithium fluoride as a lithium source in a closed reaction kettle, adding a carbonic ester and nitrile mixed organic solvent system, and adding ammonium pentafluorophosphate or an organic complex thereof as a phosphorus-containing precursor, in-situ generation and directional reaction of the fluorine-phosphorus-containing active substance are realized by controlling the slow release rate of the precursor. The solid weakly-alkaline fluorine trapping agent is arranged in the system and can dynamically adsorb or complex generated hydrofluoric acid and other fluorine-containing byproducts, so that fluorine dissipation is reduced. The reaction process is divided into three continuous windows of low-activity pre-reaction, directional main reaction and activity stabilization by regulating and controlling the reaction temperature, the stirring rate and the solvent polarity in stages, so that controllable reaction and uniform conversion of fluorine-containing phosphorus substances are ensured. And after the reaction is finished, gradually carrying out cooling crystallization, solid-liquid separation and drying to obtain a high-purity lithium hexafluorophosphate product. Therefore, generation and emission of hydrofluoric acid are remarkably reduced.

This application belongs to the field of inorganic chemical waste recycling and fluoride preparation technology, specifically relating to a method for preparing potassium fluorotitanate from hydrofluoric acid waste liquid. The method includes: S1. Pretreatment of hydrofluoric acid waste liquid and titanic acid powder; S2. Adding the pretreated hydrofluoric acid waste liquid and titanic acid powder to a reaction vessel to generate a fluorotitanic acid solution; S3. Adding potassium carbonate to the fluorotitanic acid solution to generate potassium fluorotitanate, followed by purification of the reaction solution to obtain potassium fluorotitanate crystals; S4. Washing and drying the potassium fluorotitanate crystals to obtain a high-purity potassium fluorotitanate product. This application uses titanic acid powder as the titanium source and optimizes reaction parameters to achieve the dual goals of resource recovery from hydrofluoric acid waste liquid and low-cost preparation of high-purity potassium fluorotitanate.