817 results about "Fluorhydric Acid" patented technology

The invention relates to a comprehensive utilization method of fluosilicic acid containing hydrogen fluoride, which comprises the following steps: 1) reacting a stock solution containing fluosilicic acid with a potassium fluoride raw material, and carrying out solid-liquid separation to obtain potassium fluosilicate and a hydrofluoric acid solution; 2) reacting potassium fluosilicate with a sodium hydroxide raw material, and carrying out solid-liquid separation to obtain a mixture of a potassium fluoride solution, sodium fluoride and silicon dioxide; and returning the potassium fluoride solution to the step 1) to be recycled as a potassium fluoride raw material. According to the scheme, hydrofluoric acid is prepared from fluosilicic acid containing hydrogen fluoride, sodium fluoride and water glass products are produced at the same time, no other byproduct waste is produced, and the raw material utilization rate is high. And meanwhile, the method has the advantages of low raw material cost, low equipment cost and low energy consumption cost, can generate remarkable economic benefits, and is suitable for popularization and application.

The invention provides a waste photovoltaic module high-value recovery process based on pyrolysis and wet purification, which comprises the following steps: carrying out pyrolysis decarburization on a waste photovoltaic module to obtain a glass plate, a crystalline silicon battery piece and a copper-tin soldering strip; the method comprises the following steps of: performing alkaline leaching on a crystal silicon cell to obtain a dealuminized crystal silicon wafer, performing acid pickling on the dealuminized crystal silicon wafer to obtain a silver-removed crystal silicon wafer and a silver leaching solution, and extracting a silver elementary substance from the silver leaching solution; removing impurities from the silver-removed crystal silicon wafer through a hydrofluoric acid solution to obtain a high-purity crystal silicon wafer; recovering a copper strip from the copper-tin soldering strip through a high-temperature smelting reduction method; after fluorine-containing pyrolysis gas generated in the pyrolysis process is subjected to combustion and heat exchange, hydrogen fluoride is removed in a two-stage alkali liquor absorption mode, then washing is conducted, and finally obtained flue gas is discharged. According to the wet purification process, the waste crystalline silicon battery piece can be subjected to high-purity recovery, and the crystalline silicon piece, silver and copper with high purity can be obtained. The hydrogen fluoride is removed by adopting a two-stage alkali liquor absorption method, so that the treatment efficiency of the hydrogen fluoride in the pyrolysis gas is improved.

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 relates to the technical field of metal material surface treatment, in particular to a high-cleanliness rust-proof surface treatment process for a double-H control shell, which comprises the following steps: immersing the shell in an aqueous solution containing hydrofluoric acid, citric acid, nano titanium dioxide-graphene composite powder and polyethylene glycol, and performing ultrasonic degreasing activation; then carrying out coupling treatment by using an ethanol solution containing KH-550 silane and hydroxylated carbon nanotubes; then spraying an anti-rust solution containing fluorine-silicon modified epoxy resin and zinc oxide-titanium dioxide core-shell particles, and carrying out gradient curing to form a film; and finally, after argon plasma bombardment, ultraviolet irradiation hole sealing is carried out. According to the process, through multi-step innovative treatment, a composite protective film is formed on the surface of the shell, particulate pollutants are reduced to 5 / cm < 2 > or below, the contact angle is increased to 130 degrees or above, the salt mist tolerance is over 1500 hours, the film layer is thin, the hardness is high, the adhesive force is high, the environment friendliness and economical efficiency are achieved, and diversified industrial requirements can be met.

The invention discloses a method for detecting trace chromium element in copper foil based on ICP-OES (Inductively Coupled Plasma-Optical Emission Spectrometer), which comprises the following steps: soaking a lithium battery copper foil in a mixed solution of concentrated nitric acid and hydrofluoric acid for high-temperature digestion, adding a scandium internal standard solution, and fixing the volume to obtain a solution to be detected; preparing a mixed standard solution of chromium element and scandium element with a plurality of concentration gradients, and establishing a standard curve through ICP-OES; and determining the content of the chromium element in the to-be-detected solution according to the standard curve. The lithium battery copper foil is digested through a mixed acid system, concentrated nitric acid provides an acid environment and an oxidation effect, hydrofluoric acid promotes dissolution, it is ensured that the copper foil is completely dissolved, and the digestion efficiency is improved; a scandium internal standard method is introduced, a dynamic background correction mode of ICP-OES is adopted, a scandium internal standard element can correct signal fluctuation in a sample introduction process, dual guarantee is formed by the scandium internal standard element and dynamic background correction, interference of a copper matrix on a Cr spectral line is specifically eliminated, and the trace chromium element detection precision is remarkably 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 present application relates to the field of fine chemical industry, and particularly to a preparation method of sodium tetrafluoroborate; the present application uses hydrofluoric acid, boric acid and soda to prepare sodium tetrafluoroborate; the present application uses evaporation, polar organic solvent dissolution, separation, modified polytetrafluoroethylene membrane fine filter filtration, cooling crystallization and the like to purify sodium tetrafluoroborate; the present application uses a polytetrafluoroethylene membrane filter core, vinyl guanidine, sodium acrylate, 1-allyl-3-ethyl imidazole tetrafluoroborate, an initiator and deionized water to prepare a modified polytetrafluoroethylene membrane filter core; the modified polytetrafluoroethylene membrane filter core prepared by the present application can effectively improve the purity of sodium tetrafluoroborate; the present application has the characteristics of low cost, simple process, low toxicity and environmental friendliness; the present application has mild reaction conditions in the preparation process, is easy to operate, has low energy consumption and high product purity.

The invention relates to the technical field of high-temperature alloy materials, and provides an N10276 profiled bar and a forming method thereof.The surface of a blank is coated with a three-layer composite sheath, the blank is heated in a partitioned and gradient mode, the temperature of a side wing plate area is 50-100 DEG C higher than that of a web plate area, the metal fluidity of a side wing plate is improved, cogging rolling, four-roller reciprocating finish rolling, partitioned and gradient cooling and secondary solution treatment are conducted, and the N10276 profiled bar is obtained. A nitric acid and hydrofluoric acid mixed solution is used for pickling and stripping the composite sheath, an oxide layer is removed, intergranular corrosion is avoided, a triple sheath synergistic protection mechanism is adopted, oxygen is physically isolated by outer stainless steel, and heat loss is inhibited by a middle yttria-stabilized zirconia ceramic fiber layer.

The invention belongs to the technical field of chemical detection, and particularly relates to a method for detecting the content of boron in soil and sediment, which comprises the following detection methods: S1, weighing a sample and putting the sample into a digestion tank; s2, adding a digestion solution into the digestion tank; s3, after uniform stirring, putting the digestion tank into a microwave digestion instrument for microwave digestion; s4, after digestion is completed, closing the microwave digestion instrument, and after the digestion tank is cooled to the room temperature, filtering to remove precipitates; s5, transferring the digestion solution into a volumetric flask, and fixing the volume for subsequent analysis; and S6, analyzing the digestion solution by using ICP-OES / MS (Inductively Coupled Plasma-Optical Emission According to the method for detecting the boron content in the soil and the sediment, ammonium fluoride is used for replacing hydrofluoric acid in boron detection of the soil and the sediment, use of toxic reagents is reduced, mannitol is added, a stable complex is formed by mannitol and boron, and the recovery rate of boron is increased.

The invention relates to a PEM ternary alloy catalyst for water electrolysis hydrogen production and a preparation method thereof, and belongs to the technical field of water electrolysis catalysts. 1-butyl-3-methylimidazolium tetrafluoroborate is introduced in the generation of a carrier manganese dioxide to increase the specific surface area of the carrier, fluorine doping and oxygen vacancy construction are realized on the surface of the carrier through hydrofluoric acid treatment, and then a metal precursor is dispersed through an ethylene glycol / water system; and finally, loading and alloying of the alloy nanoparticles are completed through hydrothermal reduction and heat treatment. The morphology and electronic structure of the carrier are synergistically regulated and controlled through ionic liquid and fluorine doping, the specific surface area and active sites are remarkably increased, strong interaction of metal and the carrier is achieved through ternary alloy component optimization, and the oxygen evolution reaction activity and stability of the catalyst and the precious metal utilization rate are effectively improved.

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 present application relates to a kind of preparation method of bismuth trifluoride, belong to bismuth compound preparation technical field.The preparation method of bismuth trifluoride of the present application includes the following steps: bismuth-containing compound powder is hydrothermally reacted with hydrofluoric acid;The bismuth-containing compound is one or any combination of bismuth oxide, bismuth oxychloride, bismuth trichloride.The preparation method of bismuth trifluoride of the present application carries out hydrothermal reaction to bismuth oxide, bismuth oxychloride, bismuth trichloride and hydrofluoric acid, and the high temperature and high pressure generated by hydrothermal reaction are used to improve the reactivity, solve the problem that bismuth oxide, bismuth oxychloride and bismuth trichloride are not completely reacted with hydrofluoric acid under normal pressure, resulting in low yield and low purity, product can be obtained by one-step reaction.The preparation method of bismuth trifluoride of the present application is simple, and route is short, the solvent used is water, cost is low, yield is high, and it is economic and environmental protection.

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 provides a method for extracting tantalum and niobium from tungsten tailings, and belongs to the technical field of rare metal recovery, and the method comprises the following steps: adding a reducing agent, a fluxing agent, a covering agent and a slag former into the tungsten tailings, and heating and smelting under the protection of inert gas to obtain an alloy ingot; the alloy ingot is crushed and then leached through hydrochloric acid, and acid leaching residues containing tantalum, niobium and tungsten are obtained; the acid leaching residues are subjected to alkaline leaching, and alkaline leaching residues containing tantalum and niobium are obtained; the alkaline leaching residues are leached through hydrofluoric acid and sulfuric acid, and decomposition liquid is obtained; and extracting and separating the decomposition liquid to obtain tantalum hydroxide and niobium hydroxide, and respectively calcining the tantalum hydroxide and niobium hydroxide to obtain tantalum oxide and niobium oxide. The method is simple in technological process, convenient to operate, low in cost and suitable for industrial production, tantalum and niobium can be efficiently extracted from tungsten tailings, and good economic benefits and environmental benefits are achieved.

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.

The invention belongs to the technical field of chemical engineering and fine fluorine chemical synthesis, and particularly relates to a preparation method of sulfuryl fluoride chloride. According to the preparation method, through the synergistic effect of a gas-liquid reaction system and a closed-loop circulation system, a tertiary amine hydrofluoric acid adduct (such as Et3N.nHF, n = 2-6) is used as a fluorinating reagent, sulfuryl fluoride chloride is generated through a rapid cross-flow reaction in excessive sulfuryl chloride (SO2Cl2) under the conditions that the temperature is 65-100 DEG C and the pressure is 0.5-2.0 MPa, and a liquid-phase byproduct tertiary amine hydrochloride hydrogen fluoride adduct (such as Et3N.HCl. (n-1) HF) is used for preparing the sulfuryl fluoride chloride. Supplementing hydrogen fluoride to regenerate the catalyst and recycling; and after a gas-phase product is pressurized, rectified and purified by a light component removal tower and a heavy component removal tower, totally returning a light component (Cl2 / SO2) and a heavy component (SO2Cl2) to a synthesis system for recycling. According to the method, the reaction temperature, the reaction pressure, the liquid phase dispersion degree and the contact time are accurately controlled, so that the reaction product generates SO2FCl with high selectivity, and the byproduct (R3N.HCl. (n-1) HF) is kept in a liquid phase, so that the reaction can be continuously carried out, and conditions are created for subsequent treatment.

The invention discloses a sodium-ion battery electrolyte and a preparation method thereof, and relates to the technical field of sodium-ion batteries, the electrolyte comprises a sodium salt, a composite solvent, an additive and an auxiliary agent, the sodium salt is formed by compounding sodium bis (fluorosulfonyl) imide, sodium bis (trifluoromethanesulfonyl) imide and modified sodium bis (oxalato) borate, and the composite solvent is formed by compounding sulfolane, 1, 3-butanediol, 1, 3-butanediol, 1, 3-butanediol, 1, 3-butanediol, 1, 3-butanediol, 1, 3-butanediol, 1, 3-butanediol, 1, 3-butanediol and 1, 3-butanediol. The auxiliary agent is nano-scale ZIF-8, the additive is 1, 3-propylene glycol dimethyl ether, dimethyl carbonate, fluoroethylene carbonate and ethyl acetate, the additive is modified 1, 3-propane sultone, trimethyl phosphate and hydroquinone dimethyl ether, and the auxiliary agent is nano-scale ZIF-8. According to the electrolyte, sodium bis (oxalato) borate is modified after being treated by hydrogen peroxide and has efficient hydrofluoric acid resistance, meanwhile, hydrofluoric acid generated by the reaction of fluorine-containing sodium salt and water in the electrolyte can be specifically removed by utilizing an auxiliary agent of the nano ZIF-8 and a synergistic effect formed by the sodium salt and the auxiliary agent, and damage of the hydrofluoric acid to a negative electrode SEI film is avoided; and the cycle life of the sodium ion battery is prolonged.

The invention relates to the technical field of element detection, in particular to a method for measuring the manganese content in copper concentrate, which comprises the following steps: weighing a copper concentrate sample with the mass of m in a tetrafluoroethylene beaker, and adding a small amount of water to soak the sample; adding nitric acid and hydrochloric acid, and heating at 200-300 DEG C for 5-10 minutes; then adding perchloric acid and hydrofluoric acid, heating at 200-300 DEG C until the copper concentrate sample is completely dissolved, and cooling to room temperature; adding dilute nitric acid, and heating to dissolve the separated salt crystals to obtain a to-be-detected pre-solution; transferring the to-be-detected pre-solution to a volumetric flask, adding water to dilute the pre-solution to a scale line, and uniformly shaking to obtain a to-be-detected solution; according to the method, a nitric acid-hydrochloric acid-perchloric acid-hydrofluoric acid mixed acid digestion system is adopted, so that the manganese element in the copper concentrate is completely dissolved, and the interference of a complex matrix on manganese determination is effectively solved; by combining the high sensitivity and multi-element analysis capability of the inductively coupled plasma emission spectrometer, a linear standard curve of a manganese element characteristic spectral line and concentration is established, and the accuracy and precision of quantitative analysis are remarkably improved.

The invention belongs to the technical field of secondary batteries, and particularly relates to a preparation method of bis (fluorosulfonyl) imide salt. The preparation method of the bis (fluorosulfonyl) imide salt provided by the invention comprises the following steps: reacting hydrofluoric acid, alkali metal fluoride and bis (chlorosulfonyl) imide under a closed condition at the temperature of 100 DEG C or above, cooling to 10 DEG C or below after the reaction is completed, carrying out primary filtration to obtain a filter cake, heating to 100 DEG C or above, carrying out secondary filtration to obtain a filtrate, and drying to obtain the bis (fluorosulfonyl) imide salt. And removing impurities to obtain the bis (fluorosulfonyl) imide salt particles or a bis (fluorosulfonyl) imide salt solution. By controlling the reaction temperature and the temperature of two times of filtration after the reaction, the product and impurities are separated by utilizing the crystallization characteristics and solubility of the components in the reaction system at different temperatures, so that the high-purity bis (fluorosulfonyl) imide salt is prepared by a solvent-free one-pot method.

The invention discloses an acidification blocking remover for an oil field and a preparation method of the acidification blocking remover. The acidification blocking remover comprises the following raw materials in parts by weight: 40-60 parts of hydrochloric acid, 10-20 parts of hydrofluoric acid, 5-10 parts of fluoboric acid, 1-3 parts of a modified stabilizer, 0.1-0.5 part of imidazoline and 20-30 parts of water. The modified stabilizer contains a quaternary ammonium salt structure which can be combined with negative charges on the clay to form a modified stabilizer coating on the surface of the clay, a polysiloxane molecular chain on the modified stabilizer can form a layer of hydrophobic film on the surface, and due to incompatibility between water molecules and hydrophobic groups, the hydrophobic film repels water groups, so that the clay can be degraded. Alkyl long chains on the outer side are combined with a hydrophobic membrane formed by polysiloxane molecules to form a second layer of hydrophobic membrane, then a bimolecular membrane is formed on the surface of the clay, the hydrophobic effect of the bimolecular membrane is far higher than that of a traditional monomolecular membrane, external moisture is effectively prevented from entering clay particles, and hydration expansion of the clay is inhibited.

The invention relates to the technical field of quartz sand purification, in particular to a green and efficient purification method of high-purity quartz sand, which comprises four steps of mechanical-chemical synergistic pretreatment, microwave-assisted deep impurity removal, directional adsorption purification and ultrapure water washing and drying. The traditional hydrofluoric acid process is replaced by the composite organic acid, so that the COD (Chemical Oxygen Demand) of the wastewater is reduced by more than 90%, the waste liquid treatment cost is greatly reduced, meanwhile, the problem of corrosion of strong acid to equipment is avoided, the energy consumption is reduced by 40% through the microwave process, and no chlorine is discharged, so that the production process is more environment-friendly and safer, the content of Al2O3 is reduced from 500ppm to 8ppm, and the production cost is reduced. Compared with the prior art, the method provided by the invention has the advantages that the content of Fe2O3 is reduced from 200ppm to 3ppm, meanwhile, the inclusion removal rate is greater than 99.5%, and the purity of SiO2 reaches 99.995%, so that the problem that micron-sized inclusion impurities are difficult to deeply remove is solved, and the purification efficiency is greatly improved.

The invention discloses a preparation method and a detection method of a total carbon content test solution in titanium tetrachloride, and belongs to the technical field of component detection and analysis. The preparation method and the detection method comprise the following steps: adding water into a titanium tetrachloride sample to fully react, and heating and evaporating the obtained product to dryness at the temperature of not higher than 90 DEG C; then adding a hydrofluoric acid solution and a proper amount of water, heating and dissolving at the temperature of not higher than 80 DEG C to obtain a clear and transparent solution, and adding water to dilute and fix the volume to obtain the solution for testing the total carbon content in the titanium tetrachloride. And fully shaking up the test solution, and then immediately determining the total carbon content in the solution by adopting ICP-MS or ICP-OES (Inductively Coupled Plasma-Mass Spectrometry). The method disclosed by the invention is simple and rapid to operate, small in reagent dosage and low in test solution acidity, and can effectively solve the problems that coexisting components such as high-concentration Cl <-> and H < + > in the TiCl4 sample solution interfere a detection result and corrode an instrument.

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 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.