1330 results about "Strong acids" patented technology

The invention discloses a method for preparing a high-stability W / O / W type multiple Pickering emulsion based on Janus particles, and belongs to the technical field of colloid and interface chemistry. According to the preparation method, the Janus particles with different hydrophilic and hydrophobic properties are prepared by using alkylsilane modified SiO2 with different chain lengths, the multiple emulsion is stabilized together, different types of Janus particles are adsorbed on different oil-water interfaces, and the interface activity and amphipathicity of the Janus particles are fully exerted to prepare the high-stability multiple emulsion. The multi-emulsion provided by the invention has excellent stability, keeps stable under the conditions of long-term storage, strong acid, strong alkali, high-concentration electrolyte and the like, and can effectively expand the practical application of the multi-emulsion.

The invention discloses alkali-activated porous carbon and a preparation method thereof, and relates to the field of new material preparation, and the preparation method comprises the following steps: uniformly mixing matrix carbon and a strong alkaline substance according to a mass ratio to obtain a mixed material, putting the mixed material into a crucible, and carrying out high-temperature calcination and cooling on the mixed material under the protection of an inert atmosphere; washing and filtering the mixed material subjected to high-temperature calcination for 3-6 times by using deionized water; after washing is completed, strong acid is used for soaking; and after soaking, filtering to obtain a mixed material filter cake, soaking the mixed material filter cake in ionized water, repeatedly washing, and drying until the pH value is neutral. The porous carbon material is prepared through alkali activation, the preparation steps are simple, expensive auxiliary equipment is not needed, the cost is low, preparation is safe, and the method has extremely high economic benefits and large-scale application prospects.

The invention discloses a gemigliptin oxalate and a crystal form, a preparation method and application thereof, relates to the technical field of medicinal chemistry, and provides the crystal form of the gemigliptin oxalate, the crystal form is not reported in the prior art, and animal experiments show that compared with gemigliptin tartrate and gemigliptin hydrochloride, the crystal form of the gemigliptin oxalate has the advantages that the crystal form of the gemigliptin oxalate is more stable. The gemigliptin oxalate prepared by the invention has better pharmacokinetic performance, and lays a foundation for development and application of a new dosage form of gemigliptin; the invention further provides a simple and efficient gemigliptin salt forming process, compared with a method for removing an amino protecting group through acid treatment, the salt forming process provided by the invention does not need to add alkali to dissociate the amino group, impurity generation caused by strong acid or strong alkali is avoided, and the prepared gemigliptin oxalate is high in purity.

The invention relates to the technical field of municipal sludge treatment, in particular to a method for recycling nitrogen and phosphorus elements from municipal sludge. According to the method, the municipal sludge is subjected to hydrothermal carbonization treatment, the treated solid-phase product is dried and ground to a specific particle size, the solid-phase product is subjected to acid leaching under a specific condition to extract the phosphorus element, and then heavy metal and metal elements such as Al and Fe in the acid leaching liquid are removed by adopting strong-acid ion exchange resin and a chemical precipitant, so that the phosphorus element is obtained. And finally, mixing the struvite with a hydrolyzate which is subjected to hydrothermal carbonization treatment and is rich in ammonia nitrogen, and precipitating by adjusting the element proportion and the pH value to obtain a solid-phase product struvite crystal. According to the method, external nitrogen-containing substances do not need to be added, the content of heavy metal in the solid-phase product struvite can be effectively reduced, the recovery rate of phosphorus can reach 93% or above, the recovery rate of ammonia nitrogen can reach 63% or above, the recovery rate of nitrogen and phosphorus is high, energy consumption is low, and the treatment cost is low.

The invention provides an acid-resistant COFs material capable of rapidly and efficiently adsorbing thorium ions and a preparation method thereof, the COFs material is prepared by reacting an aldehyde monomer trialdehyde phloroglucinol and an amine monomer, and the amine monomer is 2, 5-diamino terephthalic acid or 4, 4 '-diamino-[1, 1'-biphenyl]-3, 3 '-dicarboxylic acid. The functionalized COFs material prepared by regulating and controlling the grafted carboxyl has excellent thorium ion adsorption performance, has high adsorption capacity under the condition of strong acid (pH = 1-3), reaches the maximum adsorption capacity of 696 mg / g within 10 hours under the conditions that the initial concentration C0 is 400 ppm and the pH = 3, reaches the maximum adsorption capacity of 225 mg / g within 10 hours under the conditions that the initial concentration C0 is 400 ppm and the pH = 1, and has excellent thorium ion adsorption performance. And meanwhile, the catalyst has high stability in a strong acid environment and shows excellent regeneration cycle performance.

The invention relates to the field of organic chemical synthesis, in particular to a synthetic method and application of pyrimidone compounds. The invention provides a synthesis method, reactants are o-amino heterocyclic formamide and triethyl orthoformate respectively, a solvent system is a hexafluoroisopropanol solvent, and a product is a heterocyclic pyrimidone compound. The reaction does not need strong acid or strong alkali conditions, does not need additional reducing agents or oxidizing agents, does not need transition metal catalysis, is economical and practical, the reaction conditions are relatively mild, and the synthesized pyrimidone compound has a good antibacterial effect.

The invention discloses a multi-element solid waste-based auxiliary cementing material and a preparation method thereof, the cementing material is prepared by taking steel slag, carbide slag and sintered red mud which are acidified and modified by microbial bacteria as raw materials, adding water, mixing and carbonizing; according to the invention, mineral components in the steel slag are effectively utilized, and the steel slag is modified through acid production of solid waste and microorganisms, so that a new mode of resource utilization of wastes is successfully established, and conversion from wastes to resources is realized; the carbon immobilization capacity of the modified steel slag is obviously enhanced through microbial modification, full-amount carbonization of the steel slag is achieved, compared with a traditional acid leaching carbonization method, the method is not limited to partial carbonization through filtrate any more, the preparation method is green and safe, environmental pollution and potential safety hazards caused by adopting strong acid in chemical acidification are avoided, and the method has great application prospects.

The invention relates to the technical field of catalyst recovery, and discloses a method for simultaneously recovering noble metal and a carrier in a supported waste catalyst. The roasted waste catalyst is added into dilute acid and chloride to be dissolved, and solid-liquid separation is carried out; adding alkali, a ligand and water into the solid, carrying out complex reaction, and carrying out solid-liquid separation; and washing the solid for multiple times to obtain a carrier, mixing washing water with liquid obtained by two times of solid-liquid separation, and extracting noble metal. According to the method provided by the invention, use of high-concentration strong acid is avoided, the structure of the carrier is perfectly maintained, and efficient recovery of noble metal components and the carrier in the waste noble metal catalyst is realized; meanwhile, the method is simple and easy to implement, mild in operation condition and suitable for industrial production.

The invention discloses a shaft temperature measuring device which comprises a controller, a collecting part, a balance weight part and a connecting part used for connecting the collecting part and the balance weight part, the collecting part is electrically connected with the controller, an electric control gate is arranged at the bottom of the collecting part, and the electric control gate is electrically connected with the controller. The collecting part is used for measuring and collecting various required data, the position of the strong acid reagent is adjusted through opening and closing of the electric control gate so as to act on the connecting part, the connecting part fails to connect the collecting part and the counterweight part, then the collecting part is separated from the counterweight part, the collecting part is recycled, and the data is obtained. The device has the beneficial effect that the temperature field in the single-well shaft can be accurately measured.

The invention provides an acid-excited lithium slag-based cementing material and a preparation method thereof.The preparation method of the acid-excited lithium slag-based cementing material comprises the steps that lithium slag and mixed acid liquor are evenly mixed, and excitation is conducted for a preset time length; wherein the mixed acid liquor comprises one or more of sulfuric acid, nitric acid, hydrochloric acid, phosphoric acid, formic acid, acetic acid, propionic acid and oxalic acid; filtering to obtain acid-excited lithium slag, and drying to obtain dry lithium slag; the dry lithium slag and auxiliary materials are mixed and ground to a preset specific surface area, and the lithium slag-based cementing material is prepared. The strong acid is utilized to quickly destroy the silicon-oxygen structure and the silicon-aluminum structure of the lithium slag, so that the strong acid is in contact with water to generate a hydration product, and the hydration activity of the lithium slag-based cementing material is improved. The risk of alkali aggregate reaction is avoided, and the cost is reduced; moreover, acid excitation is carried out at the raw material end, so that the excitation effect is more stable than that of use end excitation of alkali excitation. Therefore, the stability of the excitation effect and the mechanical property of the material are improved.

The invention discloses a short b-axis ZSM-5 molecular sieve as well as a synthesis method and application thereof, tetraethyl orthosilicate and aluminum isopropoxide are taken as an aluminum source, tetrapropylammonium hydroxide is taken as a template agent, ammonium salt is added as an auxiliary agent to limit the growth of particles along a b axis, after a hydrothermal crystallization reaction, the obtained product is washed, baked and calcined, and the short b-axis ZSM-5 molecular sieve is obtained. The method disclosed by the invention is simple to operate, has repeatability, small template agent dosage and low cost, the synthesized ZSM-5 molecular sieve has the advantages of good thermal stability, high specific surface area, strong acid center, slow carbon deposition speed in reaction and the like, meanwhile, more active sites can be exposed, the transmission path of reactants and products is shortened, the diffusion resistance is reduced, and the method is suitable for industrial production. The catalyst is used for catalytic synthesis of pyridine and derivatives thereof, and has high selectivity and high catalytic activity.

The invention relates to the technical field of new material application, and discloses a magnetic bead material for enriching a sulfydryl peptide fragment and a preparation method thereof.The magnetic bead material prepared from micron carboxyl magnetic beads, dodecane dicarboxylic acid dihydrazide and SPSP has a long chemical reaction connecting arm, so that a reaction group has the better freedom degree, the reaction with sulfydryl is better facilitated, and the magnetic bead material can be used for enriching the sulfydryl peptide fragment. The enrichment efficiency is relatively high. When the magnetic bead material is prepared, micron carboxyl magnetic beads and dodecane dicarboxylic acid dihydrazide are based on hydrazine group and carboxyl condensation, the condensation reaction is more selective and more stable, the reaction is carried out under a milder condition, the reaction product is stable, and the reaction efficiency is higher at a lower reaction temperature. Dodecane dicarboxylic acid dihydrazide and SPSP are based on a reaction of N-succinimide and hydrazine, N-succinimide has high specificity to amino-containing molecules, side reactions are reduced, the reaction is generally carried out at room temperature, strong acid and alkali conditions are not needed, and protection of other sensitive groups is facilitated.

The invention provides a high-quality potassium hydroxide refining and impurity removal process, belongs to the field of potassium hydroxide impurity removal, and aims to overcome the defect that the purity of a potassium hydroxide product is reduced due to defects in removal precision and process stability during potassium hydroxide impurity removal in the prior art. The method comprises the following steps: carrying out oxidation decomposition on organic matters and precipitating calcium and magnesium ions, carrying out coarse filtration to remove large-particle impurities, carrying out graded filtration by adopting a three-stage series inorganic membrane module, carrying out efficient interception on impurities with different particle sizes by accurately controlling the pressure, temperature and flow rate of each membrane layer, and carrying out hydrochloric acid neutralization and potassium sulfite dechlorination to optimize the indexes of the brine. And finally, trace calcium and magnesium ions are deeply removed by utilizing the selective adsorption characteristics of the chelate resin and the strong acid cation resin, and after the resin is saturated, the resin is eluted, regenerated and recycled through acid and alkali with specific concentration, so that the impurity removal effect of potassium hydroxide is improved.

The invention relates to a defoaming agent with fast dispersion, low cloud point, high temperature and high pressure resistance, strong acid and strong alkali resistance, which is prepared from the following components in percentage by weight: 5%-50% of white carbon black silicon paste, 1%-25% of terminated polyether modified polysiloxane, 0.1%-10% of spherical polysilsesquioxane, 1%-25% of compound polyether, 0.1%-10% of thickening agent, 0.05%-0.5% of sterilizing agent and the balance of water, and the sum of the weight percentages of the components is 100%. The invention also provides a production process of the defoaming agent, which comprises the following steps of: stirring the white carbon black silicon paste, the spherical polysilsesquioxane and the terminated polyether modified polysiloxane by using a homogenizer to be fully mixed, then adding the compound polyether, the thickening agent and the sterilizing agent, uniformly stirring, and continuously and quickly stirring for 25-35 minutes by using the homogenizer to obtain the defoaming agent. The uniformly mixed polyether modified polysiloxane defoaming agent is obtained. The invention aims to provide the defoaming agent which is high in dispersion speed, low in cloud point, resistant to high temperature and high pressure and resistant to strong acid and strong alkali.

The invention relates to an acylhydrazone bond-connected covalent organic framework material, in particular to an acylhydrazone bond-connected covalent organic framework material as well as a preparation method and application thereof, and aims to overcome the defects of various materials for adsorbing Pd (II) in one aspect or the defects of poor stability and durability in high-acidity and high-radioactivity environments. Or the adsorption selectivity on Pd (II) is not strong. As an emerging crystalline organic porous polymer, the covalent organic framework is mainly formed by connecting pure organic structural units through dynamic covalent bonds, has the advantages of permanent high porosity, low density, high chemical stability, high thermal stability and the like, and is expected to realize Pd (II) adsorption in strong acid and ray irradiation environments.

The invention discloses a preparation method of an acid-resistant chlorine-resistant selective palladium adsorbent, and relates to a preparation method of a selective palladium adsorbent. The invention aims to solve the technical problems of poor structural stability, low adsorption capacity, poor selectivity and difficulty in cyclic regeneration of the existing palladium adsorbent in strong acid and high chlorine systems. According to the preparation method, fumarinonitrile is taken as a cyanogen-containing monomer, zinc chloride is taken as a catalyst, a triazine skeleton network is constructed through an ionothermal trimerization reaction, no organic solvent or expensive catalyst is needed in the process, the reaction condition is mild, the process is simple and convenient, and good environmental compatibility is achieved; the PdCl4 < 2->-doped porous carbon material provides abundant coordination sites, has a relatively large specific surface area and a developed porous structure, can effectively promote mass transfer and adsorption of metal ions, can form stable complexation with PdCl4 < 2->, shows extremely high palladium adsorption capacity and selectivity, and can still keep structural integrity and adsorption activity under strong acid and high chlorine conditions.

The utility model discloses a strong acid and alkali resistant and corrosion resistant silica gel hose which comprises a silica gel layer, the inner layer of the silica gel layer is fixedly connected with a first corrosion resistant layer, the outer side of the silica gel layer is fixedly connected with a high temperature resistant layer, the outer side of the high temperature resistant layer is provided with a reinforcing unit, and the reinforcing unit comprises a filling layer. The filling layer is fixedly connected to the outer side of the high-temperature-resistant layer, an arc-shaped block is fixedly connected to the inner side of the filling layer, a connecting block is fixedly connected to the outer side of the arc-shaped block, a connecting ring is arranged on the outer side of the connecting block, a second corrosion-resistant layer is fixedly connected to the outer side of the filling layer, and a wear-resistant layer is fixedly connected to the outer side of the second corrosion-resistant layer. And by arranging the first corrosion-resistant layer and the second corrosion-resistant layer, the silica gel hose can be conveniently reinforced from inside to outside, the overall corrosion resistance of the hose is enhanced, and the situation that the hose is corroded by strong acid and strong alkali solutions, and liquid in the hose leaks out is avoided.

The invention relates to the technical field of heavy metal wastewater treatment, in particular to an electrochemical device and an extraction method for extracting copper from copper-containing wastewater, an anode material of the electrochemical device is one of activated carbon, graphite, lead dioxide, BDD and CumX1-a-bYaZb, a cathode material of the electrochemical device is one of CunX1-c-dYcZd and a carbon-selenium compound, and after a cathode and an anode are connected with a power supply, the copper is extracted from the copper-containing wastewater. The device is used for treating copper-containing wastewater. Wherein 1 < m < = 2, 1 < = n < 2, and m > n; 0 < = a < = 1, 0 < = b < = 1, and 0 < = a + b < = 1; 0 < = c < = 1, 0 < = d < = 1, and 0 < = c + d < = 1; x, Y and Z are selected from one of S, Se and Te. The copper-based chalcogenide is used as an electrode material and forms an electrochemical device with other electrodes, the device is an electro-catalysis coupling deionization system with electrochemical oxidation complex breaking performance, and the selective removal effect on Cu < 2 + > in organic complex copper-containing wastewater, strong acid wastewater and wastewater interfered by high-concentration salt ions and heavy metal ions is good; by means of the device, the complexing breaking effect on an organic complexing pollutant Cu-EDTA can be effectively achieved, and then Cu < 2 + > extraction is completed.

The invention relates to the technical field of cables, and provides a corrosion-resistant insulated power cable. The corrosion-resistant insulated power cable is sequentially provided with a conductor layer, an insulating layer and a sheath layer from inside to outside, and the insulating layer is prepared from the following raw materials in parts by weight: low-density polyethylene, magnesium hydroxide and calcium carbonate composite powder, an antioxidant, dicumyl peroxide, zinc stearate and polyethylene wax; the sheath layer comprises the following raw materials in parts by weight: PVC resin, magnesium hydroxide and calcium carbonate composite powder, diisononyl phthalate, a calcium-zinc composite stabilizer, an antioxidant, polyethylene wax and calcium stearate. According to the corrosion-resistant insulated power cable prepared in the invention, the corrosion resistance of the power cable in extreme corrosion environments such as strong acid, strong alkali, high-concentration salt mist and the like is improved, and the condition that a common cable sheath is easy to expand and crack in the extreme corrosion environments is improved.

The invention relates to a method for constructing a composite super-hydrophobic coating through double bonding. The preparation method comprises the following steps: taking a clean copper sheet which is not pretreated as a substrate, dipping the copper sheet in a suspension consisting of nanoparticles and sulfydryl-containing siloxane ethanol, taking out, washing, drying, dipping in a perfluoromercaptan ethanol solution, taking out, washing, and drying to obtain the copper-based super-hydrophobic surface coating. The coating prepared by the method has excellent super-hydrophobicity, icing resistance and stability. Different from an existing conventional preparation method, the method has the advantages that pretreatment operation such as abrasive paper polishing, strong acid etching or anodic oxidation does not need to be carried out on a copper sheet, and micro-nano roughening and low-surface-energy self-assembly can be completed on the copper surface only through two-step normal-temperature dipping. The method is simple in preparation process, mild in condition, free of expensive equipment, thin in coating thickness and small in influence on electric conduction and heat conduction of the copper substrate, intrinsic performance of copper can be reserved, the electric conduction / heat conduction characteristic of the copper substrate is considered, and the method has wide application value and prospects.

The invention discloses an extracting agent for extracting and separating nickel cobalt and lithium magnesium, which relates to the technical field of extracting agents and is a composite extracting agent consisting of an extracting agent A and a synergistic extracting agent B, the extraction agent A is tertiary carbon carboxylic acid and salt thereof, the synergistic extraction agent B is composed of a synergistic extraction agent a and a synergistic extraction agent b, the synergistic extraction agent a is naphthalene sulfonic acid and salt thereof, and the synergistic extraction agent b is alcohol R5OH. The invention provides a synergistic extraction system of nickel and cobalt. Tertiary-carbon carboxylic acid with the carbon atom number of 10-20, tertiary-carbon sulfonic acid with the carbon atom number of 10-20 and fatty alcohol with the carbon atom number of 8-16 cooperate with each other. The tertiary carbon carboxylic acid, the tertiary carbon sulfonic acid and the fatty alcohol are matched, so that the tertiary carbon carboxylic acid, the tertiary carbon sulfonic acid and the fatty alcohol have very good selectivity and relatively strong extraction capacity on nickel ions and cobalt ions; and the defects that the water solubility of an existing extraction system is high and strong acid enters a water phase when the strong acid is used for reverse extraction are effectively overcome.

The invention discloses a mesoporous BEA molecular sieve and a preparation method and application thereof. The average pore diameter R of the mesoporous BEA molecular sieve is 2-8 nm, the specific surface area S mesopores of mesopores is 150-500 m < 2 > / g, the ratio of S mesopores to S micropores is 1.5-7, and the Na content is lower than 1.0%. According to the NH3-TPD result, the ratio of weak acid to medium-strong acid in the mesoporous BEA molecular sieve is (0.8-2): 1. The mesoporous BEA molecular sieve is relatively high in mesoporous specific surface area and relatively large in average pore size, is beneficial to diffusion of reactants and products in an aromatic hydrocarbon deolefination reaction, and can obviously prolong the service life of a catalyst and slow down inactivation of the catalyst; the Na content of the molecular sieve is low, post-treatment such as acid exchange or ammonium exchange is not needed, and the molecular sieve can be directly used.

The invention discloses a method for recovering platinum and palladium from high-cobalt nickel-containing carbonylation slag, and relates to the technical field of non-ferrous metal carbonylation metallurgy, the method comprises the following steps: S1, hydrogen reduction and activation; s2, feeding into a high-pressure carbonylation reactor; and S3, efficient carbonylation. According to the method, the carbonylation slag is subjected to hydrogen reduction activation treatment, nickel protoxide and cobalt oxide are changed into simple substance nickel, the simple substance nickel is fed into a carbonylation reactor for carbonylation under the protection of reducing gas or inert gas after activation treatment, 95% of Ni, 85% of Fe and 80% of Co are carbonylated to enter a gas phase after carbonylation, bonding of cobalt and a platinum solid solution is broken through carbonylation, and the nickel-cobalt-cobalt-cobalt-cobalt alloy is obtained. Nickel protoxide is difficult to dissolve in various strong acids and oxidizing acids, and a foundation is laid for further separation of base metals and non-metallic element sulfur from precious metals to produce high-grade platinum concentrate.

The invention discloses an internal-acid and external-alkali type organic-inorganic hybrid molecular sieve catalyst as well as a preparation method and application thereof, and belongs to the technical field of heterogeneous catalytic materials and chemical processes. According to the catalyst, a hydrogen type Beta molecular sieve is used as an acidic inner core, polyvinylpyrrolidone (PVP) is used as an organic shell, and a unique inner-acid outer-alkali structure is formed. The preparation method comprises the following steps: hydrothermally synthesizing a hydrogen type Beta molecular sieve with a specific silica-alumina ratio, and then coating PVP through surface adsorption. The catalyst is used for catalyzing the condensation of methylal and trioxymethylene under mild conditions (40-70 DEG C and normal pressure) to prepare polyoxymethylene dimethyl ethers (DMMn). The PVP shell covers acidic sites on the outer surface of the molecular sieve to form an external neutral / weak base and internal strong acid microenvironment, so that the secondary side reaction of the product is effectively inhibited, the trioxymethylene conversion rate of more than 98% and the DMMn selectivity of more than 96% can be obtained in the reaction at 50 DEG C and normal pressure, the product distribution can be regulated and controlled, and the traditional Anderson-Schulz-Flory distribution limitation is broken through. The catalyst disclosed by the invention has the advantages of high activity, high selectivity, mild conditions and easiness in separation, and has a good industrial application prospect.

The invention provides a high-temperature-resistant degradable temporary plugging agent and fracturing fluid synergistic system and an application method thereof, and the synergistic system maintains a weak acid environment in a construction stage, protects the core strength of the temporary plugging agent to be slowly attenuated, and ensures stable pressure bearing of a plugging layer; in the flow-back stage, a coating layer of the temporary plugging agent is rapidly damaged by injecting a strong acid activating solution, the specific surface area of the temporary plugging agent is rapidly increased, and rapid hydrolysis of an inner core polymer chain is commonly catalyzed by cooperating with high temperature, so that rapid and thorough degradation of the temporary plugging agent is realized. By means of the design, the temporary plugging agent perfectly balances the contradiction between tough plugging in the construction period and rapid plugging removal after construction is completed, the application window of the temporary plugging fracturing technology in a complex high-temperature reservoir is greatly widened, the reservoir damage risk caused by temporary plugging agent residues is effectively reduced, and the fracturing transformation efficiency and the oil and gas well flowback rate are improved.

A treatment composition that includes a treatment adjunct and a population of core / shell delivery particles, where the shell is made from an acid-treated chitosan and a cross-linking agent, where the acid-treated chitosan results from treating chitosan with a weak acid, or even a mixture of a strong acid and a weak acid. Related methods of making and using such compositions.

The present application discloses a kind of dispersing fast, low turbidity, high temperature and high pressure resistant, strong acid and strong alkali defoaming agent, which is prepared from the following components: 5-50% of white carbon black silica paste, 1-25% of capped polyether modified polysiloxane, 0.1-10% of spherical poly siesquioxane, 1-25% of compound polyether, 0.1-10% of thickening agent, 0.05-0.5% of sterilizing agent, and the balance of water, wherein the sum of the weight percentages of the components is 100%. The present application also provides a production process of the defoaming agent, which comprises the following steps: stirring the white carbon black silica paste, spherical poly siesquioxane and capped polyether modified polysiloxane with a homogenizer to mix them thoroughly, then adding the compound polyether, thickening agent and sterilizing agent, stirring them uniformly, and continuing to stir them rapidly with the homogenizer for 25-35 minutes to obtain the mixed uniform polyether modified polysiloxane defoaming agent. The purpose of the present application is to provide a defoaming agent with fast dispersion speed, low turbidity, high temperature and high pressure resistance, and strong acid and strong alkali resistance.

The invention discloses a preparation method of a eutectic solvent for separating and recycling metals in waste crystalline silicon photovoltaic panels. According to the method, betaine hydrochloride is used as a hydrogen bond acceptor, ethylene glycol is used as a hydrogen bond donor to prepare a deep eutectic solvent with high solubility, and copper chloride is used as an oxidizing agent to leach metal silver and metal aluminum in the waste photovoltaic panel crystal silicon wafer. The leaching system is easy to operate, strong acid and strong alkali used in traditional wet recovery do not participate in the leaching system, and the problem of discharge of waste gas and waste water is solved. In the recovery process, the used ammonia water and water can be reused after rotary evaporation. Compared with a traditional crystalline silicon photovoltaic panel recycling route, the method has the advantages that the technological process is shortened, the cost is reduced, and an effective method is provided for recycling the waste crystalline silicon photovoltaic panel.

The invention belongs to the technical field of chemical synthesis, and particularly relates to a method for preparing 5-methylfurfural by using 2-methylfuran. The special solid acid catalyst is used for replacing traditional phosphorus oxychloride, hydrogen chloride and phosphorus-containing wastewater are eliminated from the source, and the sulfolane is used for replacing DMF (Dimethyl Formamide), so that solvent residues in the product are reduced. The solid catalyst SO4 < 2-> is modified to form a strong Bronsted acid site (-SO3H) which cooperates with Ce < 3 + > / Ce < 4 + > redox to inhibit carbon deposition, selectively activate 2-methylfuran alpha-C and inhibit side reactions, so that the selectivity and yield of a target product are improved. Na2CO3 neutralization is replaced by electrochemical neutralization, salt slag solid waste is eliminated, and environmental pollution is reduced. After the organic phase is dried and dewatered through a molecular sieve, most of the solvent is removed through rotary evaporation, and the residual crude product is subjected to centrifugal molecular distillation, so that unreacted raw materials and trace impurities are effectively removed, and the product purity is remarkably improved.

The synthesis method comprises the following steps: S1, adding furandicarboxylic acid into a reaction container, adding a certain amount of methanol, adding a double-acid-site strong acid solid catalyst, starting stirring, controlling the reaction temperature to carry out esterification reaction, and after the reaction is finished, filtering, washing and drying to obtain furandihydrazide; separating out the double-acid-site strong acid solid catalyst to obtain clear liquid, namely dimethyl furandicarboxylate; s2, transferring dimethyl furandicarboxylate serving as a raw material into another reaction container, adding a certain amount of sodium formate serving as a catalyst, then adding a proper amount of hydrazine hydrate, controlling the reaction temperature, keeping a reflux state, reacting for a period of time, cooling to room temperature after the reaction is finished, and performing centrifugal separation to obtain white solid furandihydrazide. The synthesis method has the advantages of simple reaction steps, no need of toxic and harmful catalysts, mild reaction conditions, high conversion rate and high yield, and can realize efficient, green and low-cost production of furandihydrazide.