1114 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 relates to the technical field of metal surface treatment, and discloses a titanium felt surface pickling process which is characterized by comprising the following steps: step 1, pretreating a titanium felt; step 2, preparing a pickling solution, wherein the pickling solution comprises 3-5% (by volume) of hydrofluoric acid, 15-20% (by volume) of nitric acid, 0.5-1% (by mass) of a corrosion inhibitor and the balance of deionized water; 3, acid pickling is conducted, specifically, the pretreated titanium felt is hung in an acid pickling tank through a clamp, it is ensured that the titanium felt is completely immersed in an acid pickling solution, a stirring device is started, the speed is controlled to be 100-200 r / min, the temperature is controlled to be 30-40 DEG C, and acid pickling is conducted for 5-15 min; and step 4, cleaning. The titanium felt surface pickling process has the advantages of being efficient in cleaning, low in damage, environmentally friendly and safe.

The invention discloses an environment-friendly titanium alloy etching solution as well as a preparation method and an etching method thereof, and relates to the technical field of printed circuit board production. The environment-friendly titanium alloy etching solution comprises the following components in percentage by mass: 10-30% of ammonium fluoride, 5-15% of an oxidant, 0.1-1% of a wetting agent, 0.3-1.5% of a stabilizer, 2-10% of an accelerator and 0.5-3% of a lateral erosion inhibitor. The stabilizer is selected from at least one of Tween 20, Tween 40 and Tween 85; and the accelerator is selected from at least one of sodium methylene dinaphthalene sulfonate, sodium dibutyl naphthalene sulfonate and dodecyl benzoate. The environment-friendly titanium alloy etching solution disclosed by the invention can selectively and quickly etch titanium alloy without corroding a copper surface and other metals, so that etching factors are effectively increased, and the problem of lateral erosion of a fine circuit is solved. Meanwhile, ammonium fluoride is used as a main agent of the etching liquid instead of hydrofluoric acid, so that the environmental pollution can be effectively reduced.

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 invention provides a zirconium alloy metallographic specimen preparation method which comprises the following steps: (1) pretreatment: intercepting a specimen, avoiding a heat affected zone, and removing greasy dirt on the surface of the specimen; (2) mechanical grinding, wherein the mechanical grinding comprises step-by-step grinding by using metallographic abrasive paper; (3) chemical polishing: chemical polishing comprises the steps of preparing a chemical polishing solution, soaking the sample in the solution and cleaning and wiping the sample, and the chemical polishing solution comprises nitric acid, hydrofluoric acid, oxalic acid and deionized water which are mixed and placed in a polyethylene container; and (4) post-treatment: placing the sample in a nitrogen protective atmosphere furnace, forming an oxide layer on the surface of the sample, and removing residual oxide particles. According to the method, nitric acid, hydrofluoric acid, oxalic acid and deionized water are mixed and placed in a polyethylene container, and the sample is chemically polished, so that the metallographic test piece of the zirconium alloy can be safely and effectively treated, and observation and analysis of a metallographic structure are guaranteed.

The invention discloses a phosphogypsum leachate-carbonate rock dynamic corrosion reaction analysis method based on numerical simulation, and aims to research a migration-corrosion coupling mechanism of acid leachate in a carbonate rock fracture network. The method comprises the following steps: firstly, acquiring a two-dimensional image sequence of a rock core sample through CT (Computed Tomography) scanning, carrying out operations such as threshold segmentation, membrane enhancement and a light shading algorithm on an image by utilizing AVIZO software, extracting fracture structure parameters and establishing a high-precision three-dimensional model; then, multiple groups of simplified models with different fracture widths are constructed in COMSOL Multiphysics, a Darcy flow field and a solute concentration field are coupled on the basis of the Darcy law and a dilute matter transfer theory, and the dynamic corrosion effect under the multi-field coupling effect is quantitatively represented by setting hydraulic gradient boundary conditions and chemical reaction kinetic parameters; the dynamic corrosion reaction process of calcium ions, hydrofluoric acid, sulfuric acid and phosphoric acid in the ardealite leachate and carbonate rocks with different crack widths is accurately simulated.

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.

A novel additive, an electrolyte, and a lithium ion battery, relating to the technical field of lithium ion batteries. The electrolyte comprises a lithium salt and a non-aqueous solvent for dissolving the lithium salt, the electrolyte further comprises an electrolyte additive, the electrolyte additive comprises a positive electrode film-forming additive and a negative electrode film-forming additive, and the electrolyte additive further comprises a fluoro isocyanate-based pyridazine organic compound. The additive can absorb moisture and hydrofluoric acid in the electrolyte, reduce the dissolution of transition metals, improve the thermal stability of lithium hexafluorophosphate, and maintains the stability of a ternary material under high voltage; a sulfuric acid group on the novel additive can be oxidized by oxygen at a positive electrode, so that the oxygen generated when an LFO lithium supplementing agent is activated is absorbed, the capacity exertion, high temperature cycle and high temperature storage of the LFO lithium supplementing agent are significantly improved, and the DCIR of the battery will not obviously increase, thereby improving the stability of the battery.

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 pickling paste, a preparation method thereof and application of the pickling paste to removal of an alpha layer on the surface of titanium alloy, and belongs to the technical field of alloy surface treatment. Based on 100 parts by mass, the pickling paste is prepared from the following raw materials in parts by mass: 10-20 parts of nitric acid; 30-40 parts of hydrofluoric acid; 10 to 20 parts of magnesium nitrate; 2 to 5 parts of an associative polyurethane emulsion; and the balance of solvent. The invention further discloses a preparation method of the titanium alloy pickling paste and application of the titanium alloy pickling paste to removal of an alpha layer on the surface of titanium alloy. The titanium alloy pickling paste is used for treating the titanium alloy surface, the removal rate of an alpha layer on the titanium alloy surface is 100%, the harmful surface layer on the titanium alloy surface can be effectively removed in time, and the product quality and the production schedule are guaranteed.

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 provides a sample dissolving method of a nickel-based alloy, and belongs to the technical field of analytical chemistry, and the nickel-based alloy comprises the following components in percentage by mass: 0.15-0.20% of C, 0.15-0.20% of B, 0.15-0.20% of C, and the balance of Fe and inevitable impurities. Comprising the following steps: preliminarily dissolving a sample through concentrated hydrochloric acid and concentrated nitric acid; adding perchloric acid, and preserving heat for 1-2 minutes at the temperature of 100-120 DEG C to obtain a yellow insoluble substance, the ratio of the adding volume of the perchloric acid to the mass of the sample being (110-130) mL: 1g; transferring the liquid and the yellow insoluble substance into a second reaction cup, adding hydrofluoric acid, and keeping the temperature at 50-60 DEG C for 2-4 minutes; and fixing the volume after dissolving. Firstly, concentrated hydrochloric acid and concentrated nitric acid are adopted for dissolution, due to the fact that the content of Cr, Mo and W is high, and detection of Ce, Si and other metals cannot be affected, the adding mode of the concentrated nitric acid and the concentrated hydrochloric acid is limited, then perchloric acid is added, fuming of the perchloric acid is controlled, and the content of the perchloric acid and the content of the concentrated nitric acid which are added in the earlier stage are combined; the method has the advantages that low Cr content due to generation of CrO2Cl2 is avoided while metal carbides are dissolved, undissolved yellow substances are dissolved in combination with hydrofluoric acid, and low Si content due to generation of SiF4 is avoided.

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 invention provides a method for removing Ca element in a high-purity quartz sand sample and high-purity quartz sand prepared by the method. The method comprises the following steps: S1, carrying out primary hydrochloric acid leaching; s2, acid leaching with hydrofluoric acid; s3, secondary hydrochloric acid leaching; and S4, acid leaching with hydrochloric acid and hydrofluoric acid. The method disclosed by the invention has the beneficial effects that fine cracks can be generated in the quartz by utilizing the difference of dielectric constants of impurities and a quartz matrix through microwave acid leaching, and the contact reaction of the impurities and acid liquor is promoted, so that solid inclusions in the quartz are removed; and different acids are used for gradient synergistic acid leaching, so that the removal efficiency of Ca impurity elements in the quartz is improved, and the high-purity and stable high-purity quartz sand is obtained.

The utility model relates to the technical field of chemical production equipment, and particularly discloses a chlorine-containing hydrogen fluoride separation system which comprises a condensing tower and an absorption separation tower which are sequentially connected, an absorption separation device comprises a tower body, a distribution disc and a filler section are sequentially arranged in the tower body from top to bottom, and a liquid inlet and a gas outlet are formed in the upper end of the tower body; a liquid outlet and an air inlet are formed in the lower end of the tower body, the air inlet and the liquid inlet are both formed in the radial direction of the tower body, and the liquid outlet and the air outlet are both formed in the axial direction of the tower body; dilute sulfuric acid is introduced into the liquid inlet. The utility model aims to solve the problem that the absorption and separation effect of chloride ions in fluosilicic acid of a separation system is not ideal in an existing production system for preparing hydrofluoric acid by a fluosilicic acid method.

The invention provides a method for fully and efficiently dissolving polycrystalline silicon, which comprises the following steps: A) crushing, digesting and cleaning, washing and drying polycrystalline silicon to obtain pretreated polycrystalline silicon; carrying out digestion cleaning on the pretreated polycrystalline silicon by using a first digestion solution; b) mixing the pretreated polycrystalline silicon with a second digestion solution, and heating for digestion; c) continuously heating and digesting the solution until the solution is nearly dry, adding hydrofluoric acid to drive silicon, continuously heating the solution until the solution is nearly dry, and adding nitric acid to drive acid; and D) adding nitric acid, continuously heating the solution until the solution is nearly dry, and adding dilute nitric acid for rinsing to complete the dissolution of the polycrystalline silicon. The method disclosed by the invention is simple to operate, high in dissolving efficiency and suitable for large-scale industrial production; according to the invention, complete dissolution of polycrystalline silicon can be realized, and the accuracy of a test result is ensured. According to the method disclosed by the invention, sufficient dissolution and removal of silicon can be ensured, the on-machine requirement of ICP MS (Inductively Coupled Plasma Mass Spectrometer) is met, and the equipment loss is reduced.

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 discloses a recycling method of NF3 residual electrolysis liquid, and relates to the technical field of residual electrolysis liquid recycling treatment. The method comprises the following steps: step 1, removing Fe ions in the electrolytic residual liquid: firstly, adding hydrogen peroxide or oxygen into the electrolytic residual liquid for reaction, oxidizing ferrous ions into ferric ions, then adding ammonia water and sodium hydroxide or ammonium bicarbonate and sodium hydroxide into the solution for reaction, precipitating ferric ions in the form of ferric hydroxide; 2, hydrofluoric acid is added into the electrolyte solution obtained after iron removal to adjust the pH of filtrate to 3-12, the filtrate enters an extraction system, the nickel element in ammonium hydrogen fluoride is extracted out, and ammonium hydrogen fluoride is purified; and step 3, the nickel element separated from the electrolyte enters a second section to be extracted and synthesized into a nickel sulfate product.

The invention belongs to the technical field of crystal defect testing, and particularly relates to an FPD testing method for a monocrystalline silicon wafer micro-viewpoint defect, which comprises the following steps: accurately cutting off the head and the tail of a silicon rod to eliminate an end defect, and preparing a pure substrate by adopting an A-surface machine grinding / B-surface maintaining asymmetric treatment and segmented cleaning process; after pretreatment with a specifically proportioned corrosive liquid, carrying out temperature-controlled etching by using potassium dichromate-hydrofluoric acid to form a characteristic V-shaped pattern on the surface, and realizing visual identification by corresponding different defects to different patterns; gridding detection points are designed based on stress distribution, laser positioning coordinate mapping is performed, an imaging-correction-noise reduction-segmentation-intelligent classification algorithm chain is constructed to realize full-automatic detection, and a detection-analysis-optimization full-process data driving quality control system is established through visual data such as a thermodynamic diagram and a type matrix. And large-scale production of semiconductor silicon wafers is supported.

The invention relates to the technical field of silica powder surface modification, in particular to a novel silica powder surface modification method and application of a composite material of the novel silica powder surface modification method. Silica powder surface modification comprises the steps that silica powder is subjected to surface chemical modification through a titanate coupling agent, active functional groups are introduced, and the interface bonding force between the silica powder and MXene is enhanced; high-quality preparation of MXene: etching an MAX phase by adopting hydrofluoric acid (HF) or lithium fluoride / hydrochloric acid (LiF / HCl), and obtaining few layers of MXene nanosheets through ultrasonic stripping to ensure high conductivity and large specific surface area; the modified silica powder and MXene dispersion liquid are uniformly mixed, MXene stacking is inhibited, the specific surface area is increased, and the ion transmission efficiency is improved; mXene nanosheets grow on the surface of the silica powder in situ to form a core-shell structure, so that the interface bonding strength and the mechanical property are enhanced; the composite material is applied to the fields of electromagnetic shielding, energy storage, flexible electronics and the like.

The invention discloses a continuous synthesis coordinated temperature control integrated method of fluorobenzene. The method comprises the following steps: carrying out salt-forming exothermic reaction on hydrogen fluoride liquid and aniline liquid in a salt-forming tubular reactor to obtain aniline hydrofluoride; carrying out diazotization exothermic reaction on aniline hydrofluoride and sodium nitrite solid in a diazotization tubular reactor to obtain diazonium salt; performing multi-stage pyrolysis exothermic reaction on the diazonium salt in a multi-stage temperature control tubular reactor to obtain pyrolysis liquid; performing liquid-liquid centrifugal separation on the pyrolysis liquid to continuously obtain a fluorobenzene product; thermal coupling heat exchange channels are respectively arranged among a sodium nitrite solid feeding pipeline, a diazonium salt feeding pipeline, an aniline hydrofluoride feeding pipeline, a diazotization tubular reactor, a hydrogen fluoride liquid feeding pipeline, liquid-liquid centrifugal separation equipment, an aniline liquid feeding pipeline, a salifying tubular reactor and a multi-stage temperature control tubular reactor, so that heat transfer temperature control is realized; according to the invention, continuous synthesis of fluorobenzene and temperature control integrated control are realized, and batch continuous stable production of fluorobenzene is further promoted.