92 results about "Alkaline etching" patented technology

The invention provides a glass ceramic strengthening method and strengthened glass ceramic, and belongs to the technical field of glass ceramic processing. The glass ceramic strengthening method comprises the following steps: sequentially carrying out first-time surface modification treatment, toughening treatment, second-time surface modification treatment and organic acid treatment on the glass ceramic, the first surface modification treatment and the second surface modification treatment independently comprise at least one of polishing treatment, alkaline etching treatment and inorganic acid liquid etching treatment. The glass ceramic is sequentially subjected to the first surface modification treatment, the toughening treatment, the second surface modification treatment and the organic acid treatment, so that the roughness can be reduced, and the impact resistance of the glass ceramic is remarkably improved.

The invention relates to the technical field of biomedicine, in particular to a preparation method of sequential targeting mesoporous manganese oxide nano-enzyme and application of the sequential targeting mesoporous manganese oxide nano-enzyme in treatment of ischemia reperfusion induced acute kidney injury. Adding a potassium permanganate solution into the silicon dioxide nanoparticle dispersion liquid under ultrasonic waves, and carrying out alkali etching to obtain mesoporous manganese oxide nanoparticles (HMN); and after surface amination modification, connecting with a mixed PEG spacer layer, and reacting with thiolated SS31 and azidoacyl hyaluronic acid to obtain the nano-enzyme. The preparation can effectively penetrate through a damaged glomerulus filtration barrier and is passively enriched in a damaged kidney, damaged renal tubular epithelial cells over-express CD44 receptor mediated hyaluronic acid modified nano-particle endocytosis is enhanced, SS31 modified nano-particles achieve lysosome escape mitochondrial targeting in cells, the level of active oxygen in mitochondria can be reduced, and the activity of the mitochondria can be improved. The mitochondrial function is recovered, the renal function and tissue pathological injury are improved, and accurate anti-oxidation treatment on the acute kidney injury is realized.

The invention relates to forming a local p-type polycrystalline silicon through an approach of local p-type doping followed by selective alkaline etching enabling five different crystalline silicon-based single junction and bottom structure for tandem architectures solar cells.

The application relates to a preparation method of a glass substrate with a through hole, which comprises the following steps: scanning a predetermined through hole area of a glass substrate by using a laser; immersing the scanned glass substrate into an alkaline etching solution to perform alkaline etching until a micro through hole with an inner diameter of 5-15 microns is formed through the glass substrate; the alkaline etching is performed under the assistance of megasonic waves with a frequency of 0.5-2 MHz; immersing the glass substrate with the micro through hole into an acidic etching solution to perform acidic etching until the inner diameter of the micro through hole reaches a target value, and the glass substrate with the through hole is prepared. The above method realizes efficient longitudinal etching on the glass substrate, greatly improves the depth-width ratio of the through hole, reduces the side etching amount, and obtains the glass substrate with the high-depth-width-ratio and high-precision through hole.

The present invention provides an alkaline etching additive, an alkaline etching solution, and a method for cleaning wrap-around polycrystalline silicon. The alkaline etching additive comprises a protective component and a component for accelerating the etching of silicon, and can increase the etching rate of polycrystalline silicon, protect an oxide layer of a PN junction and increase the difference between the etching rates of B / PSG and polycrystalline silicon etched by an alkali. The additive enables the etching rate of polycrystalline silicon to reach 960 nm / min, whereas the reaction rates for PSG and BSG are 5.4 nm / min and 7.2 nm / min, respectively, thereby achieving the complete isolation of P and N regions and improving the battery yield. An anionic surfactant and a dispersant improve the cleaning efficiency and a polishing effect. Compared with traditional acid washing and soda ash washing methods, the additive can not only increase the removal rate of polycrystalline silicon, but can also protect the structure of a battery, expand a process window and improve the production stability. The technique is particularly suitable for the preparation of batteries having a TOPCon structure, and improves the performance and stability of a battery by optimizing the deposition and cleaning processes of polycrystalline silicon.

The invention discloses a modified aluminum composite current collector and a preparation method thereof, and relates to the field of lithium ion battery current collector materials. The method comprises the following steps: sequentially carrying out alkaline degreasing, alkaline etching, bright dipping and secondary activation pretreatment on the alloy aluminum foil; chemically plating a Ni-P alloy base layer on the surface of the aluminum foil; then electroplating a graphene composite zinc layer in an acidic plating solution containing carboxylated modified graphene by taking the chemically-plated aluminum foil as a cathode and a high-purity zinc plate as an anode; and finally, washing, hot air drying and inert atmosphere annealing are performed to prepare the modified aluminum composite current collector. Through the double-layer structure of the chemical plating Ni-P layer and the electroplating graphene composite zinc layer, the problems that a traditional aluminum foil interface is large in contact resistance, low in first efficiency, poor in mechanical property and unstable in conductivity are effectively solved, the comprehensive performance of the product is excellent, the process is stable, the cost is controllable, and the method is suitable for industrial production of the lithium ion battery.

This is an alkaline etching process for glass, and the technical process involves immersing a glass substrate in an alkaline etching solution. The alkaline etching solution is a 40% to 56% concentration sodium hydroxide solution, the temperature of the alkaline etching solution is 100 to 130°C, and the immersion time is 100 to 300 minutes. The alkaline etching process for glass can be used for thinning glass and anti-glare treatment of glass surfaces, and can also be used to remove the convex points of the uneven micro-nanopoints of anti-glare glass to achieve a non-sparkle effect or a low-sparkle effect. By selecting sodium hydroxide (caustic soda) from the two major industrial alkalis and changing from acid etching to alkaline etching, the etching accuracy of ultrathin electronic glass is improved and manufacturing costs are reduced. In addition, since the manufacturing process does not generate fluorine-containing wastewater or hazardous waste, i.e., fluorine-containing lime sludge, environmental pollution is reduced. This process has a significant effect on environmental protection, innovation, pollution reduction, and emission reduction.

This invention relates to the field of high-performance fiber materials technology, and discloses a long-lasting, UV-resistant, and highly stable Kevlar fiber. Using para-aramid as a matrix, it incorporates in-situ copolymerized grafted bis(aminotriazine)-benzimidazole UV-stabilizing units, and its surface is covalently bonded with a CeO2-TiO2 composite nanolayer via a silane coupling agent. This results in excellent UV resistance and structural stability, with a UPF value of 50-100+, and a strength retention rate of ≥90% after 500 hours of xenon lamp aging. It also retains ultra-high strength, high modulus, and high-temperature resistance. The preparation method includes synthesizing the bis(aminotriazine)-benzimidazole comonomer, low-temperature polycondensation of this comonomer with p-phenylenediamine and terephthaloyl chloride to obtain a copolymer spinning solution, followed by dry-wet spinning, alkaline etching, composite sol-coating, and high-temperature curing to obtain the target fiber. This invention employs dual modification through internal copolymerization and surface coating, resulting in a simple process suitable for industrial production. The obtained fiber can be used in aerospace, defense, and outdoor protection applications requiring long-term UV exposure.

The application discloses a kind of etching waste liquid recycling reaction process pH automatic control method including preparation reaction buffer and preparation two steps of basic copper chloride, wherein in preparation basic copper chloride step, the pH value of reaction system can be read in real time by pH sensor and feedback to controller, and by controller, the addition volume of acidic etching waste liquid and alkaline etching waste liquid is adjusted in real time according to system pH value, to prepare granular basic copper chloride, can realize strict control the pH value of entire process, ensure the quality of basic copper chloride, without relying on manual detection pH, production efficiency is high, and realizes accurate control feeding amount, avoid excessive addition material to cause cost increase, in addition, response speed is also improved, once reaction system pH value abnormally fluctuates, system can quickly make adjustment.

The invention discloses a manufacturing method of a circuit board and the circuit board. The manufacturing method comprises the following steps: cutting a working board according to engineering data; wherein the working plate comprises a substrate and a copper layer covering an element surface and a welding surface on two sides of the substrate; carrying out first whole plate electroplating on the working plate; covering a dry film on the surface of the element; developing the element surface; performing acid etching on the first non-circuit region; screen printing resin in the first non-circuit area; carrying out second-time whole plate electroplating on the working plate; covering a dry film on the element surface, and performing external image development on the element surface, the first circuit area being not covered by the dry film, and the first non-circuit area being covered by the dry film; electroplating a copper layer with the thickness of H3 in the first circuit area; and removing a dry film from the first non-circuit area after tinning the first circuit area so as to carry out alkaline etching on the first non-circuit area. The first non-line area is etched twice, the copper thickness of each etching is reduced, the line width compensation can be greatly reduced, and the problem that the line width compensation is small is solved.

The invention discloses a method for manufacturing a circuit board with a locally-electroplated nickel-gold bonding pad and the circuit board, and the method comprises the following steps in sequence: plating copper on a board surface; manufacturing an initial bonding pad pattern; plating nickel and gold on the bonding pad; primary film stripping: exposing the copper layer and the nickel-gold layer higher than the copper layer; performing positive sheet treatment: exposing the side wall surface at the joint of the copper layer and the nickel-gold layer; tin plating treatment: electroplating tin on the side wall surface to form a tin layer; secondary film stripping: stripping the dry film on the surface to expose the copper layer and the nickel-gold layer; and etching processing: removing the copper foil by using an alkaline etching solution so as to process an outer-layer circuit. Through an innovative process of firstly plating copper, locally plating nickel and gold, then etching a positive plate and tinning to protect a circuit on the side wall of the bonding pad, the problems of infirm dry film lamination and etching medicine permeation caused by the height difference between a nickel-gold bonding pad and a copper surface in a traditional method are effectively solved, the yield and reliability of the circuit are remarkably improved, and the functions of the bonding pad and the integrity of the circuit are considered.

This invention discloses a process for improving the stability of etching quality, relating to the field of PCB processing technology. It enables automatic closed-loop control across multiple processes, ensuring that products in the same batch can automatically use the correct production parameters under different etching copper thickness results, achieving consistent product quality. The process for improving etching quality stability includes the following steps: encoding each production board individually → setting up a code reader before each process → database establishment → drilling → copper plating → board plating → copper thickness measurement → external light imaging → pattern electroplating → alkaline etching → drying → line width detection → data feedback. By encoding each production board individually, detecting copper thickness before etching, and detecting line width after etching and recording the data in a database, the optimal etching production speed is calculated through rules, and the etching speed of subsequent production boards is adjusted. This achieves data accumulation while further improving the stable control of the etching production speed.

The utility model provides an ammonia water evaporation and absorption device in an alkaline etching liquid regeneration process, the device comprises an evaporation unit, a condensation collection unit and an absorption unit, the evaporation unit comprises an evaporator, the condensation collection unit comprises a condenser and a condensate collection tank, the absorption unit comprises a jet device and a regeneration liquid absorption cylinder, and the regeneration liquid absorption cylinder is connected with the evaporator. A top outlet of the evaporator is connected with the condensate collecting tank through the condenser, a top outlet of the condensate collecting tank is connected with a gas phase inlet of the jet device, a liquid phase inlet of the jet device is connected with a bottom outlet of the regenerated liquid absorption cylinder, and an outlet of the jet device is connected with an inlet of the regenerated liquid absorption cylinder. According to the utility model, by arranging the evaporation, condensation collection and absorption structure units and adopting an ammonia water evaporation and ammonia gas jet absorption mode, ammonia is supplemented during regeneration of the alkaline etching liquid, so that the swelling amount of the alkaline etching liquid can be effectively reduced, and the treatment cost is reduced; the device is simple in structure, small in occupied area and high in automation degree, and equipment modularization is easy to achieve.

The utility model discloses an alkaline etching liquid regeneration and copper recovery system, and relates to the technical field of electrolytic copper, the alkaline etching liquid regeneration and copper recovery system comprises an electrolytic tank, a material receiving bin and a push rod motor, the top of the material receiving bin is provided with a through groove, two sides of the through groove are fixedly connected with scrapers for scraping copper, two sides of the top of the material receiving bin are fixedly connected with barrier strips, and the barrier strips are fixedly connected with the push rod motor. And a side through groove is formed in one side of the electrolytic tank, the material collecting bin is slidably connected with the inner wall of the side through groove in a penetrating mode, the bottom of a push rod of the push rod motor is fixedly connected with a second supporting frame, and the bottom of the second supporting frame is fixedly connected with a second electrode plate. The problems that copper accumulation attached to the surface of a cathode plate can reduce the precipitation efficiency of copper in waste liquid, the cathode plate needs to be taken out for copper scraping, then the cathode plate is reinstalled and fixed in an electrolytic tank, the process of taking out and putting back is tedious, and the electrolytic efficiency is greatly reduced are solved.

The invention relates to the technical field of wafer COP defect identification methods based on detection before polishing, particularly discloses a wafer COP defect identification method based on detection before polishing, and aims to solve the problems of high invalid processing cost and low screening accuracy caused by the fact that traditional COP defect identification depends on a polished surface. The method comprises the following steps: carrying out alkali corrosion treatment on a silicon wafer to expose crystal original particle defects; selectively marking the defect area by adopting a fluorescein aqueous solution with specific wavelength and concentration; after cleaning with high-purity water and drying with compressed air, analyzing the peak position, the peak width and the strength of a defect luminescence peak through photoluminescence spectrum, and realizing accurate identification of the defect by combining a support vector machine model. By adopting the technical scheme, the wafer COP defect can be efficiently and accurately identified before polishing, the invalid polishing cost is remarkably reduced, and the process economy and the detection flux of regenerated wafer screening are improved.

There is provided a gallium nitride single crystal substrate, which is a gallium nitride single crystal substrate having a diameter of 50 mm or more, with a low-index crystal plane closest to a main surface being (0001), and in which Ge concentration in the substrate is 3×1018 cm−3 or more; and among peaks appearing in a histogram of diameters of etch pits during etching applied to the main surface with an alkaline etching solution, a first peak having a smallest diameter is a single peak having no shoulder.

The invention relates to the technical field of extraction systems, and discloses an alkaline etching liquid treatment system and a treatment method.The alkaline etching liquid treatment system comprises a liquid separation box, a groove is formed in the inner bottom face of the liquid separation box, a collecting box is placed in the groove, the groove divides the inner bottom face of the liquid separation box, and the collecting box is arranged in the groove; the material collecting tables are obliquely and downwards arranged from the ends away from the collecting box to the ends close to the collecting box; longitudinal driving mechanisms are connected to the ends, away from each other, of the upper surfaces of the liquid separation boxes, and cleaning mechanisms are connected to the driving ends of the longitudinal driving mechanisms. Sediments are guided to be directionally gathered towards the collecting box through the obliquely-arranged collecting table, the cleaning plate stably moves along the surface of the collecting table in cooperation with the cleaning mechanism driven by the longitudinal driving mechanism, the sediments are efficiently pushed into the collecting box, the sediments are prevented from being gathered and caked from the source, and the problems that a pipeline is blocked and the liquid quality is affected are completely eradicated.

The invention discloses an integral hierarchical porous reticular nickel catalyst as well as a preparation method and application thereof, and belongs to the technical field of chemical catalytic materials. According to the catalyst, a commercial nickel net is used as a supporting framework, and a porous nickel active layer with micron-level thickness is constructed on the surface of a nickel net wire, so that an integral structure with macro-mesoporous-micro hierarchical pore channels is formed. The preparation method comprises the following steps: burying the nickel net in mixed powder containing aluminum powder and an activating agent (aluminum chloride or ammonium chloride), and carrying out high-temperature roasting in an inert atmosphere to form a nickel-aluminum alloy layer on the surface of the nickel net; and then aluminum is removed through alkali liquor corrosion, and the monolithic catalyst with the raney nickel type porous structure on the surface is obtained. The catalyst has the advantages of excellent mass and heat transfer performance, high specific surface area, abundant active sites, simple preparation process and low cost. When the catalyst is applied to an adiponitrile hydrogenation reaction, high activity and high selectivity are shown. Assistants such as Fe, Cr, Mo, Co, Zn and the like can be introduced through post-modification, so that the performance is further improved.

This invention relates to a cleaning and alkaline etching process for reducing nickel contamination after polishing, belonging to the field of silicon wafer processing technology. The process includes the following steps: Step 1: In the cleaning equipment's chemical bath, the silicon wafer is pre-cleaned in the first bath before alkaline etching, followed by rapid drainage rinsing in the second bath. Step 2: In the cleaning equipment's chemical bath, the silicon wafer undergoes alkaline etching in the third bath, followed by rapid drainage rinsing in the fourth bath. Step 3: In the cleaning equipment's chemical bath, the silicon wafer undergoes post-etching cleaning in the fifth bath, followed by rapid drainage rinsing in the sixth bath. Step 4: In the seventh bath, a slow-lifting tank structure is used for cleaning in pure water at 35°C. Step 5: Infrared drying is used to remove moisture from the silicon wafer surface at 60°C. This process solves the problem of controlling Ni diffusion while ensuring production capacity. It effectively removes nickel contamination from the surface caused by the polishing process.

The present invention relates to a silicon substrate and a manufacturing method therefor, and a heterojunction solar cell and a manufacturing method therefor. The manufacturing method for the silicon substrate comprises: an initial silicon substrate comprising a first surface and a second surface, forming a first mask layer on the first surface, and forming a second mask layer on the second surface; performing first dot matrix laser etching processing on the first mask layer to form a first intermediate mask layer having holes; performing second dot matrix laser etching processing on the second mask layer corresponding to a target region on the second surface to form a second intermediate mask layer having holes, wherein the target region is used for arranging gate lines; performing alkaline etching processing on the first surface by means of the holes of the first intermediate mask layer, and performing alkaline etching processing on the target region by means of the holes of the second intermediate mask layer; and removing the first intermediate mask layer to obtain a first textured surface, and removing the second intermediate mask layer, so as to obtain the silicon substrate having a second textured surface located in the target region. In the silicon substrate manufactured by the manufacturing method for the silicon substrate, the adhesiveness between the second surface of the silicon substrate and the gate lines is excellent, and the first surface has ultra-low reflectivity.

A method of manufacturing a brazing sheet includes layering at least a core-material slab composed of an aluminum material and a filler-material slab composed of an Al—Si series alloy to prepare a clad slab. At least one aluminum slab in the clad slab, which is disposed in a range from the core-material slab to the filler-material slab inclusive, contains a metal element that oxidizes more readily than Al. The clad slab is hot rolled to prepare a clad sheet that includes a core material composed of the core-material slab and a filler material composed of the filler-material slab. Then, one or more passes of cold rolling is performed on the clad sheet. Between passes of cold rolling or after completion of the cold rolling, at least one surface of the clad sheet is etched using an alkaline etching solution having a sodium hydroxide concentration of 0.05-1.0 mass %.

The invention relates to a thick copper circuit board metallization half hole processing technology comprising the following steps: drilling holes on a laminated circuit board to prepare for subsequent PTH half holes; performing negative film drying after electroplating copper on the circuit board; copper and tin plating is carried out on the inner wall of the ultra-short slotted hole; a CNC machine tool is used for machining the metal hole, and a half hole is milled and fished out; stripping the film of the circuit board of which the half hole is fished out, and then carrying out rapid alkaline etching treatment; half-hole tin-plating dry film: pressing the tin-plating dry film on the circuit board in vacuum, and forming a window at the half-hole position; the circuit board is tinned through a pattern electroplating line, and an alkali etching resistant tin layer is plated on the exposed hole wall copper of the half hole; and carrying out film removal, etching and tin stripping treatment on the circuit board to obtain the circuit board with the half hole. The processing technology can effectively solve the problem of excessive hole wall etching caused by too slow copper thickness etching line, and can ensure that the hole wall area of the etched PTH half hole finished product is more than 90% larger than the hole wall area of the original half hole.

The utility model discloses a kind of alkaline etching tank and etching equipment, alkaline etching tank includes tank body, detection mechanism and suction mechanism, tank body is used to place alkaline etching liquid;Detection mechanism includes accommodating box and acid-base degree detector, acid-base degree detector is set into accommodating box, and acid-base degree detector is used to detect the liquid acid-base degree value in accommodating box;Suction mechanism is respectively communicated tank body and accommodating box, and suction mechanism is used to suck alkaline etching liquid in tank body to accommodating box.Etching equipment has applied above-mentioned a kind of alkaline etching tank, utilizes suction mechanism and is sucked to detection mechanism to carry out acid-base degree detection with etching liquid, without manual liquid taking, prolong the service life of acid-base degree detector, improve reliability and production safety.

The invention relates to the technical field of photocatalysis, and provides a bimetallic carbon dioxide capture and methanation catalytic material as well as a preparation method and application thereof, the catalytic material is composed of UiO-66, V-Bi19Br3S27 grown on the surface of the UiO-66 and in a pore channel in situ, an S-type heterojunction interface formed by dispersing and loading the UiO-66 and the V-Bi19Br3S27, and an Au-Er bimetallic active center on the surface of the UiO-66; the Au-Er bimetallic active center is loaded through a sequential photodeposition method, and the molar ratio of Au to Er is (1-2): (2-1); the preparation method comprises the following steps: compounding UiO-66 and V-Bi19Br3S27 through an in-situ hydrothermal method to form an S-type heterojunction; v-Bi19Br3S27 is obtained by in-situ compounding of UiO-66 and Bi19Br3S27 and alkali etching treatment, the adsorption capacity is high, the broad spectrum response is wide, the charge separation efficiency is excellent, low-concentration CO2 can be efficiently activated, direct air CO2 trapping and high-selectivity methanol conversion can be realized at normal temperature and normal pressure, and the problems of function splitting and low energy efficiency in the prior art are solved.

The invention discloses a process for transferring a stepped circuit pattern on the surface of a PCB (Printed Circuit Board). The process specifically comprises the following steps of: (1) covering a layer of photosensitive ink on the surface of the PCB; (2) carrying out low-temperature baking on the printed board; (3) exposing the photosensitive ink layer by using ultraviolet light, wherein the used exposure negative film is a negative film; (4) developing by using a weak alkali liquid plate, dissolving and removing an unexposed ink region, and exposing a circuit and a bonding pad region which need pattern electroplating; the exposed curing ink area is reserved on the plate and is used as an anti-plating layer during pattern electroplating; (5) baking the plate at high temperature; (6) feeding the board into a pattern electroplating line, and electroplating the exposed copper surface area with a required copper layer thickness; and (7) removing the cured photosensitive ink layer, performing alkaline etching, and finally forming a precision circuit. The photosensitive ink is used for replacing a dry film, so that the problem of dry film wrinkling caused by a stepped structure on the surface of the PCB is effectively solved, the open and short circuit defects after pattern electroplating are avoided, and the production yield and the product quality are improved.

The invention discloses a manufacturing method of a hot plug module printed circuit board and a circuit board. The manufacturing method of the hot plug module printed circuit board comprises the following steps: providing a PCB substrate; preparing a copper-clad plate as the PCB substrate; a circuit pattern is transferred to the surface of the PCB substrate through a dry film windowing process, the circuit pattern comprises an auxiliary wire and a golden finger, and the golden finger is conducted with a copper sheet in the PCB substrate through the auxiliary wire; secondary pattern transfer: exposing the position of the golden finger on the PCB substrate through a dry film windowing process, and covering other positions on the PCB substrate with a dry film; plating hard gold: depositing a hard gold layer on the area of the golden finger and the surrounding copper sheet connected with the auxiliary lead; third pattern transfer: exposing the area of the auxiliary wire to be etched through a dry film windowing process; and etching the auxiliary wire: etching the auxiliary wire through alkaline etching liquid, and only reserving the golden finger and the hard gold layer around the golden finger.

This invention discloses a method for promoting the flotation separation of lepidolite and feldspar across the entire particle size range through surface pretreatment. The method involves adding an alkaline solution to a slurry of lepidolite ore and gangue minerals, followed by alkaline etching under the combined action of mechanical stirring and ultrasound to obtain a surface-pretreated mineral sample. After adjusting the slurry pH to neutral, a metal ion activator and an anionic collector are added to the pretreated mineral sample for flotation, yielding lepidolite concentrate and tailings. This invention targets the flotation of lepidolite across the entire particle size range, including conventional flotation sizes of -74μm and +38μm, as well as the fine-grained size of -38μm. It effectively achieves the flotation separation of lepidolite and gangue minerals, reduces collector costs, minimizes the loss of fine-grained lepidolite, and ultimately yields a high-grade lepidolite concentrate. This invention features an innovative process flow, extremely low reagent usage, and high economic efficiency, making it significant for the separation and recovery of lepidolite and gangue minerals.

The invention discloses a method for preparing MXene through fluoride-free alkali etching of an ultrasonic-assisted supercritical fluid technology, and relates to the field of MXene preparation.Fluorine-free green preparation of MXene is achieved through cooperation of supercritical carbon dioxide fluid and a high-frequency power ultrasonic technology and a fluoride-free etching agent. The preparation method comprises the following steps: introducing carbon dioxide to reach a supercritical state, carrying out an etching reaction in the supercritical state by adopting a stirring or fluid circulation mode, applying continuous or discontinuous high-frequency power ultrasonic treatment to the whole reaction system, recovering to normal pressure and normal temperature after the reaction is finished, collecting a product, washing and drying, thereby obtaining the high-purity silicon dioxide. The high-frequency vibration of the ultrasonic waves and the high diffusivity of the supercritical carbon dioxide are utilized to promote the etching agent to remove A-layer elements in the MAX phase, so that the use of a fluorine-containing etching agent is avoided, the environmental pollution is reduced, and the etching efficiency of the MAX phase is also remarkably improved.

A method for producing structured glass articles is provided by removing glass material from a glass element. The method includes the step of etching the glass element to remove the glass material from using an etching medium. The etching medium has a basic aqueous etching solution with a pH of more than 12 and a complexing agent. The complexing agent complexes a leached constituent of the glass element.

The invention relates to a method for preparing copper sulfate pentahydrate based on PCB (printed circuit board) acidic copper-containing waste liquid and alkaline etching liquid, which comprises the following steps: S1, sequentially adding an oxidant and activated carbon into the acidic copper-containing waste liquid, then adding the alkaline etching liquid, and filtering to obtain a primary purified copper solution; s2, the primary purified copper solution and alkaline etching liquid are added into a reaction kettle at the same time for reaction, and then heat preservation and curing are conducted to obtain alkaline copper slurry; s3, carrying out solid-liquid separation on the alkaline copper slurry, and stirring and cleaning; s4, concentrated sulfuric acid is added into the cleaned alkaline copper slurry for acidification, and after alkaline copper is dissolved, a copper sulfate seed crystal is added for reaction to obtain a copper sulfate mixed solution; and S5, pumping the copper sulfate mixed solution into a cooling crystallization kettle for cooling crystallization, and carrying out centrifugal separation to obtain copper sulfate pentahydrate crystals. According to the method disclosed by the invention, the acidic copper-containing waste liquid and the alkaline etching liquid are subjected to cooperative treatment and are converted into high-purity copper sulfate pentahydrate through a process of pretreatment, synthesis, cleaning, acidification and crystallization, so that efficient conversion from complex hazardous wastes to high-value products is realized.