232 results about "Re crystallization" patented technology

The invention relates to a method for purifying an electronic-grade sulfonium salt photoacid generator. The method comprises the following steps: heating, preparing a photoacid generator stock solution, purifying through ion exchange resin, cooling, recrystallizing, carrying out solid-liquid separation, washing crystals and the like to obtain the high-purity photoacid generator, so that the metal content in the photoacid generator can be effectively reduced, the single metal content is less than 5ppb, and the yield is up to 80-90%. And mother liquor is collected and purified by resin and can be used for preparing photoacid stock solution again. The operation effectively reduces the use of an organic solvent and the generation of wastewater, can further improve the recrystallization yield, and meets the requirements of green and sustainable development.

The application belongs to the technical field of medicine synthesis and provides a preparation method of phosphonic acid levomoxiflazine disodium, which comprises the following steps: taking levomoxiflazine as raw material, performing esterification through phosphorus oxychloride and hydrolysis to obtain a reaction solution containing phosphonic acid levomoxiflazine; slowly and uniformly adding a sodium hydroxide methanol solution, first adjusting pH to 6.3-7.6, filtering out impurities, then adjusting pH to 9.1-9.8, crystallizing and drying to obtain a crude product; and performing recrystallization through a water-ethanol-acetone mixed system, filtering and drying to obtain a high-purity product. The application solves the problems of high impurity content and low yield in the prior art by optimizing the amount of esterification reagent, the pH adjustment mode and the recrystallization system, the HPLC purity of the obtained phosphonic acid levomoxiflazine disodium is greater than or equal to 99.97%, the maximum single impurity content is less than or equal to 0.02%, the process is simple, easy to operate, stable and suitable for industrial amplification production.

This invention relates to the field of hydrometallurgical technology and discloses a method for purifying and recovering ammonium perrylate using a combination of electrodialysis and ion exchange. The method first adjusts the pH of the rhenium-containing feed solution, then selectively enriches perrylate ions using electrodialysis to obtain a high-concentration rhenium-rich solution. Subsequently, the rhenium-rich solution is subjected to deep adsorption purification through an anion exchange column. Next, rhenium is eluted from the saturated resin using an eluent to obtain a pure ammonium perrylate solution. Finally, high-purity ammonium perrylate crystals are obtained through evaporation, concentration, cooling, crystallization, and drying. Optionally, the obtained crystals can be recrystallized to further improve purity. This invention ensures the purity and process stability of the rhenium-rich solution obtained in the pre-enrichment stage, improves the overall adsorption capacity, desorption rate, and reliability of the process operation of the resin, and guarantees the stability of the final ammonium perrylate product purity and the economic benefits of the entire process recovery.

The invention relates to the technical field of industrial wastewater treatment, in particular to a treatment method for treating high-sulfonic-group wastewater by advanced oxidation, which comprises the following steps: regulating the pH value of the wastewater to 3.0-4.0, then carrying out photo-Fenton oxidation, controlling the molar ratio of H2O2 to Fe < 2 + > to be 300: 1-400: 1, regulating the pH value of the effluent to 5.0-6.0, adding sodium sulfite to quench residual H2O2 and flocculate and precipitate iron mud, and finally, carrying out secondary oxidation on the wastewater to obtain the high-sulfonic-group wastewater. Performing anaerobic-aerobic biochemical treatment on the supernate, adding sodium carbonate and sodium hydroxide into biochemical effluent to soften and descale, concentrating in a mechanical vapor recompression evaporator, washing and recrystallizing crystallized mother liquor, and adsorbing and purifying the crystallized mother liquor with activated carbon to obtain an industrial salt product. The problem of MVR evaporation scaling is effectively solved by accurately controlling the neutralization pH and combining the softening step, finally, wastewater standard treatment and salt high-quality recovery are achieved, the COD removal rate can reach 95% or above, and excellent environmental and economic benefits are achieved.

The invention belongs to the technical field of biochemical engineering, and relates to an industrial extraction method and application of L-hydroxyproline adapted to the scale of a 30T fermentation tank, and the extraction method comprises the following steps: preparing raw materials; recycling membrane filtration and mother liquor; decoloring is performed; decarburization; evaporating, concentrating and crystallizing; performing centrifugal separation; drying and crushing. The method solves the technical problems that the yield is low (generally less than 70%), the process flow is long (multiple times of chromatography / recrystallization is needed), the product purity is difficult to reach the standard (most 98-99.5%) and the like, the L-hydroxyproline fermentation liquor produced by a 30T fermentation tank is used as a treatment object, efficient extraction is realized through a pretreatment-purification-refining three-stage process system, and the method is suitable for industrial production. According to the method, the primary mother liquor generated by centrifugal separation is innovatively applied to the next batch of membrane filtration process, so that raw material recycling is realized, the purity of the final product stably reaches 99.9%, the overall yield is increased to 75%, and the method has the advantages of simplified process, stable yield and controllable quality, and can be directly applied to large-scale industrial production of L-hydroxyproline.

This invention provides a method for recovering and utilizing distillation residue after solvent removal from homohydric anhydride, relating to the field of fine chemical technology. The method includes anhydride treatment, vaporization and sublimation, dissolution and recrystallization, distillation, and water washing. In this invention, the distillation residue is anhydride-treated under high temperature and negative pressure, followed by vaporization and sublimation under vacuum to separate mechanical impurities and high-boiling substances. Then, through dissolution and recrystallization, the difference in solubility between homohydric anhydride and metahydric anhydride in polar solvents is utilized to preferentially crystallize out the homohydric anhydride. The mother liquor is distilled to remove the solvent, and then colored impurities are removed by hot water washing and activated carbon adsorption. Finally, it is cooled and crystallized to obtain trimellitic acid. The homohydric anhydride obtained by this invention has a purity ≥95% and a yield of 84-89%, and the trimellitic acid has a purity ≥97% and a yield of 81-86%. This method achieves effective recovery of high-value-added components from distillation residue, demonstrating significant economic and environmental benefits and promising application prospects.

The invention discloses a perovskite light absorption layer penetrating through large crystal grains and preparation and application thereof, and a preparation method comprises the following steps: K1, obtaining a perovskite thin film with multiple layers of crystal grains; k2, treating the perovskite thin film in an anti-solvent / solvent co-evaporation atmosphere; and K3, annealing the processed perovskite thin film in an inert atmosphere to obtain the perovskite light absorption layer penetrating through the large crystal grains. The flow velocity of the anti-solvent / solvent co-evaporation atmosphere is 0.5-2 L / min; a recrystallization atmosphere is obtained by using a method of co-evaporating a mixed solution composed of an anti-solvent / solvent, the crystallized perovskite thin film is transferred to the recrystallization atmosphere to be treated, small crystal grains on the upper layer of the perovskite thin film are selectively dissolved, large-size crystal grains on the lower layer absorb the selectively dissolved small crystal grains and are recrystallized upwards under thermal driving, and the perovskite thin film is obtained. Therefore, the through perovskite thin film with a large grain size is obtained, and the efficiency and the stability of the perovskite solar cell are improved.

The present application relates to aripiprazole synthesis technical field, specifically to a kind of preparation of 1-(2,3-dichlorophenyl) piperazine hydrochloride substantially without following dimer impurity compound (I), the structure of the impurity is determined to clarify the generation mechanism of the impurity, provide the train of thought for better control of the impurity and make corresponding judgment to the impurity derived subsequently, provide help to the quality research of subsequent intermediates and finished products;The present application replaces the existing multiple recrystallization process by means of filtration and salting-out, which can effectively simplify the operation and greatly reduce the use of organic solvents.

The invention relates to a method for separating nickel sulfate from nickel, lithium and sodium ternary sulfate. The method comprises the following steps: (1) carrying out evaporative crystallization on a nickel-lithium-sodium ternary sulfate solution, carrying out heat preservation and sedimentation, and then carrying out solid-liquid separation to obtain a first mother solution and a first crystal; (2) carrying out cooling crystallization on the first mother liquor, and carrying out solid-liquid separation to obtain a second crystal; (3) carrying out first washing treatment on the second crystal, and carrying out solid-liquid separation to obtain a third crystal; (4) heating and dissolving the third crystal, cooling, recrystallizing, and carrying out solid-liquid separation to obtain a fourth crystal; and (5) carrying out second washing treatment on the fourth crystal, carrying out solid-liquid separation, and drying an obtained fifth crystal to obtain the nickel sulfate product. According to the method, the nickel sulfate crystal can be directly separated from the high-concentration nickel-lithium-sodium sulfate, the process is simple, other impurities are not introduced, the purity of the target product is high, and industrial implementation is easy.

Disclosed in the present application are a quaternary sulfate molten salt heat storage material, a composite heat storage material, and a preparation method therefor and the use thereof. The preparation method for the quaternary sulfate molten salt heat storage material comprises: subjecting first sulfate-type salt lake raw brine to freezing and recrystallization treatments to obtain sodium sulfate decahydrate; subjecting second sulfate-type salt lake raw brine to evaporative crystallization and recrystallization treatments to obtain magnesium sulfate heptahydrate; and mixing the sodium sulfate decahydrate, the magnesium sulfate heptahydrate, potassium sulfate, and calcium sulfate, heating the mixture at a first heating rate to a first dehydration temperature for a first heat treatment, then heating at a second heating rate to a second dehydration temperature for a second heat treatment, and then heating at a third heating rate to a molten blending temperature for a third heat treatment, and thereby obtaining the quaternary sulfate molten salt heat storage material. In the present application, a quaternary sulfate molten salt heat storage material is prepared by a one-step method using dehydration and coupling technology. Moreover, the specific heat of the composite heat storage material is improved by adding nanoparticles to the quaternary sulfate molten salt heat storage material.

Disclosed are methods of forming a method for forming spectrally selective nanoparticles, the method comprising: heating a growth solution comprising a zinc salt precursor, zinc oxide seed particles, and one or more dopants in a non-pressurized hydrothermal reactor to a first temperature under agitative conditions for a reaction period; cooling the reactor to a second temperature less than the first temperature for a cooling period to form a precipitate of recrystallized doped zinc oxide nanoparticles dispersed in a suspension; and separating and collecting the recrystallized nanoparticles from the suspension, wherein the collected nanoparticles exhibit a spectral selectivity in the atmospheric window.Also disclosed herein are comprising a population of polycrystalline zinc oxide nanoparticles doped with one or more dopants, wherein the population of nanoparticles is spectrally selective in the atmospheric window.

The application belongs to the technical field of natural product extraction, and provides high-purity curcumin powder and an extraction method thereof. The extraction method of the high-purity curcumin powder comprises the following steps: (1) fresh turmeric is sliced, dried, and then crushed, supercritical CO2 extraction is adopted, and curcumin oil, curcumin powder, and residues are separated; (2) the residues are subjected to fermentation-type ethanol extraction to obtain an alcohol extract; (3) the curcumin powder and the alcohol extract are combined, subjected to macroporous resin adsorption, eluted with ethanol, and then concentrated to obtain a concentrated solution; and (4) the concentrated solution is recrystallized, washed, dried, and then high-purity curcumin crystals are obtained. The extraction method adopts supercritical CO2 fluid extraction coupled with fermentation-type ethanol extraction, and the technology of gradient cooling recrystallization of ethanol and water after macroporous resin adsorption, and the steps are used and operated in cooperation. The product obtained by using the extraction method has high yield and purity, low production cost, small amount of organic solvent, and is suitable for industrial production.

The invention discloses a method for preparing battery-grade ferrous sulfate from a titanium dioxide byproduct ferrous sulfate, which comprises the following steps: (1) heating and dissolving the titanium dioxide byproduct ferrous sulfate in a solvent to form a ferrous sulfate supersaturated solution; (2) sequentially adding iron powder and sulfuric acid into the ferrous sulfate supersaturated solution, and carrying out reduction reaction; (3) adding a chelating agent into the solution obtained in the step (2), mixing, filtering, cooling, and carrying out solid-liquid separation to obtain recrystallized ferrous sulfate crystals and recrystallized saturated mother liquor; and (4) heating and dissolving the recrystallized ferrous sulfate crystal into a supersaturated solution by using a solvent, cooling and crystallizing, and repeating the recrystallization step to obtain the battery-grade ferrous sulfate. According to the method, a chemical chelation method and a recrystallization method are combined, sodium lignin sulfonate is added into the mother liquor as a chelating agent before the first recrystallization, the sodium lignin sulfonate and metal impurity ions form a stable compound, meanwhile, enrichment of the impurity ions in the mother liquor circulation process is avoided, and the purity of ferrous sulfate crystals is improved.

The application provides a glass carbon mold and a recrystallized silicon carbide product and a preparation method, and belongs to the technical field of ceramic material preparation. Microcrystalline cellulose is mixed with water, and the obtained mixture is formed to obtain a cellulose body; the cellulose body is subjected to a stabilization treatment in an oxygen-containing atmosphere to obtain a stabilized body; and the stabilized body is subjected to a carbonization treatment in a protective atmosphere to obtain the glass carbon mold. The glass carbon mold is used to prepare the recrystallized silicon carbide product, which is convenient for directly forming a complex green body and can be sintered together with the product, solves the problem that the green body is easily damaged and deformed in the transfer process, and is environmentally friendly.

The invention discloses a method for preparing omega-aminocarboxylic acid through alkaline ring-opening reaction of cyclic lactam, which comprises the following steps: adding common inorganic alkali and a proper amount of distilled water into a reaction kettle, and stirring until the common inorganic alkali is completely dissolved to obtain a solution; then adding a certain amount of cyclic lactam, and gradually heating to reflux reaction; after the reaction is completed, cooling a solution system to room temperature, dropwise adding hydrochloric acid to adjust the pH value to 7.0, and removing water to obtain a crude product of omega-aminocarboxylic acid; and adding a crystallizing agent A and a crystallizing agent B into the crude product for recrystallization, stirring for 2 hours under a low-temperature condition to obtain a large amount of white precipitate, filtering, and drying to obtain a white solid product aminoheptanoic acid. The method is simple and convenient in process operation, good in reproducibility, high in total yield, low in product metal impurity content, economical and environment-friendly, and suitable for batch industrial production.

The application provides a method for preparing 4,4'-dichlorodiphenyl sulfone through circulation catalysis, and relates to the technical field of dichlorodiphenyl sulfone preparation. Chlorobenzene and p-chlorobenzene sulfonyl chloride are reacted in the presence of a catalyst, anhydrous ferric chloride, at a first predetermined temperature to obtain a solution containing 4,4'-dichlorodiphenyl sulfone, and then the solution is cooled and filtered to obtain a 4,4'-dichlorodiphenyl sulfone crude product. The crude product is then subjected to alkaline treatment, liquid separation, concentration crystallization and recrystallization to obtain 4,4'-dichlorodiphenyl sulfone. The purity of the prepared 4,4'-dichlorodiphenyl sulfone reaches more than 99.6%, and the mother liquor obtained through concentration crystallization can be recycled, so that the raw material and the catalyst, anhydrous ferric chloride, can be reused, and waste is avoided.

The invention relates to the technical field of production of 2, 6-dimethylnaphthalene, and discloses a production method and a production system of 2, 6-dimethylnaphthalene, and the production method comprises the following steps: (1) under a liquid phase condition, in the presence of an alkyl transfer catalyst, contacting reaction raw materials with a transfer alkylating agent to obtain a product mixture; the content of the 2, 6-dimethylnaphthalene is not less than 15wt% on the basis of the total content of the bicyclic aromatic hydrocarbon in the product mixture; (2) rectifying the product mixture to obtain a light component and a heavy component containing the dimethylnaphthalene isomer, and returning the light component to the step (1) to provide at least part of reaction raw materials; (3) mixing the heavy component obtained by rectification with a complexing agent, carrying out complexing crystallization, and then carrying out alkali washing to obtain a 2, 6-dimethylnaphthalene crude product; and (4) mixing the 2, 6-dimethylnaphthalene crude product with a solvent, and recrystallizing. The method has the advantages of high purity and high yield of the 2, 6-dimethylnaphthalene.

The application relates to the technical field of organic synthesis, and discloses an organic sulfinate salt composition, a preparation method and application thereof and the composition. The preparation method comprises the following steps: contacting a monovalent organic sulfinate salt shown in formula I with a divalent metal salt or a salt of a metal with a valence higher than two under the condition that a poor solvent exists; the organic sulfinate salt prepared by the method has high yield and high purity, almost no sulfinate salt by-product is generated, the method has the advantages of simple operation, safe and easily-obtained reaction raw materials, rapid reaction, no need of recrystallization, the target product can be obtained through filtration after the reaction, less solvent is used, the cost is low, etc., the composition has the beneficial effects that the composition is more stable than a corresponding sodium salt, the sulfur odor is reduced, the composition has strong reducing capacity, etc.

This invention provides an imidacloprid recrystallization refining and purification device, belonging to the technical field of purification devices. It includes a mixing chamber inner liner, with a mixing chamber outer shell fixedly installed outside the inner liner. The inner wall of the mixing chamber outer shell and the outer wall of the mixing chamber inner liner enclose a sealed heating chamber. A crystallization chamber inner liner is provided on the side of the mixing chamber outer shell, and a cooling crystallization tube is provided inside the crystallization chamber inner liner. An adaptive disturbance mechanism is provided inside the crystallization chamber inner liner. This adaptive disturbance mechanism can adjust the disturbance amplitude of the imidacloprid solution according to its crystallization degree. In this invention, by providing an adaptive disturbance mechanism, core components such as a float, a swinging linkage, a telescopic rod, and a stirring plate are integrated. The float senses the density change of the imidacloprid solution in real time at each crystallization stage, generates corresponding buoyancy based on the density, and achieves lifting and lowering. This, in turn, links the swinging linkage to swing around the slider on the limiting post, driving the telescopic rod to extend and retract radially along the sealed tube, ultimately achieving adaptive adjustment of the disturbance amplitude of the stirring plate.

The invention discloses a production process method of an antioxidant BHT (butylated hydroxytoluene). The core of the method is to treat the recrystallization mother liquor: after the mother liquor is rectified to remove the solvent alcohol, the traditional high-temperature rectification is not adopted, and primary cooling crystallization, alkylation reaction and secondary cooling crystallization are sequentially carried out. Finally, the secondary mother liquor is produced as a liquid antioxidant LK51, and comprises 7-9% of 2-tert-butyl-p-cresol, about 35% of 4 (6)-tert-butyl-m-cresol, about 35% of 2, 6-di-tert-butyl-p-cresol, 4, 6-di-tert-butyl-m-cresol and other alkylphenols, and the total content of the alkylphenols is greater than 98%. The component is a mixture of various alkylphenols, has excellent oxidation resistance in lubricating oil, gasoline and other oil products, and can replace an antioxidant T501 and the like. According to the method disclosed by the invention, through process innovation and replacement of two-fraction alkylation of original rectification 2 by direct alkylation of the primary crystallization mother liquor, the yield of a BHT main product is increased, meanwhile, the high-added-value liquid antioxidant is co-produced, low-value heavy alkylphenol waste is eliminated, and dual improvement of energy conservation, consumption reduction and economic benefits is realized.

The invention discloses a countercurrent crystallization production process for reducing the content of impurities such as magnesium (Mg), manganese (Mn) and titanium (Ti) in ferrous sulfate heptahydrate, and belongs to the technical field of purification of inorganic compounds. According to the process, through two-stage design of'system initialization and first-batch material treatment 'and'continuous countercurrent crystallization production', by utilizing cooperative countercurrent cooperation of a dissolving kettle, a crystallization kettle, a centrifugal machine and a multi-stage mother liquor tank, cascade recycling of mother liquor and repeated recrystallization and purification of the materials are realized. According to the process, thousands of ppm of Mg, fifty hundred ppm of Mn and forty ppm of Ti in the ferrous sulfate heptahydrate crude product can be reduced to be smaller than or equal to 180 ppm, smaller than or equal to 40 ppm and smaller than or equal to 25 ppm respectively, meanwhile, the solvent water consumption is reduced by 40% or above, mother liquor emission is reduced, and the process has the advantages of being high in industrial continuity and automation degree and suitable for large-scale production of the low-impurity ferrous sulfate heptahydrate product.

This bowl is primarily intended for rice and miso soup, and is a dual structure consisting of an outer container and an inner container placed within the outer container with a gap between them, joined at the edge of the opening. The outer container has a wide opening, but its diameter narrows in a curved shape toward the bottom, making it easy to hold in your hand. The outer and inner containers are made of titanium, and their surfaces have a unique crystalline pattern created by the recrystallization of titanium.

The invention discloses a preparation method of 1-amino-2-cyano-1-cyclopentene, which comprises the following steps: 1, preparing a mixed solution, namely mixing a first organic solvent with super alkali in a protective gas atmosphere, heating by adopting a nano infrared energy-saving electric heating coil, stirring, uniformly mixing and dissolving to obtain the mixed solution; the super base is selected from one of potassium tert-butoxide, sodium tert-butoxide, sodium ethoxide, sodium methoxide and sodium hydroxide; 2, cyclization reaction: dropwise adding adiponitrile into the mixed solution, and continuously carrying out infrared heat preservation reaction for 3-8 hours to obtain a reaction solution of 1-amino-2-cyano-1-cyclopentene; 3, cooling crystallization and filtration: cooling the reaction liquid to-10-5 DEG C, standing for crystallization, and carrying out pressure filtration in a protective gas atmosphere to obtain an ACCP crude product and a filtrate; and 4, recrystallizing and refining to obtain a pure product. The method is mild in reaction condition, low in energy consumption, good in product yield and high in product purity, solves the problems of high solvent toxicity, low yield and high environmental protection pressure in the prior art, and is suitable for production of medicine and pesticide intermediates.

The invention discloses a preparation method of a foam concrete composite admixture, and relates to the technical field of foam concrete, and the specific preparation method comprises the following steps: adding an admixture, a superfine composite mineral admixture and desulfurized gypsum into a basic raw material according to a certain proportion; foams are prefabricated through a compressed air method and prepared through an air compressor; fully stirring the prefabricated foam and the mixed slurry through a mortar stirrer to prepare foam concrete; the prepared foam concrete is subjected to a drilling and grinding resistance test. Through the arrangement of the superfine mineral admixture, mineral crystal lattices can generate dislocation, bond fracture and recrystallization after superfine grinding, and a water-soluble amorphous structure is formed on the surface, so that water molecules enter the mineral admixture more easily, the hydration reaction is accelerated, and the activity index of the contained mineral is greatly improved; and the superfine composite mineral admixture suitable for producing cement can be prepared by adding a scientific formula, so that the porosity of the cement is reduced, and the density of the cement is improved.

This invention belongs to the field of organic electrochemical synthesis and microchemical technology, and relates to a method for preparing 2-chlorobenzoic acid by electrochemical reduction debromination in a continuous flow microreactor. The method includes: dissolving 3-bromo-2-chlorobenzoic acid, a supporting electrolyte, and a proton source in a polar aprotic solvent to prepare a cathode reaction solution; continuously feeding this solution into the cathode channel of a microchannel electrochemical reactor using a metering pump, while simultaneously pumping the anolyte into the anode channel; connecting a DC power supply and conducting a selective electrochemical debromination reaction under set current density, reaction temperature, and material residence time conditions; and obtaining high-purity 2-chlorobenzoic acid from the outlet material through gas-liquid separation, neutralization, extraction, and recrystallization. This invention combines a continuous flow microreactor with electrochemical debromination technology, significantly enhancing mass and heat transfer, resulting in a shorter reaction time, higher conversion and yield, and the addition of a reducing agent, ease of scale-up, and intrinsic safety, demonstrating promising industrial application prospects.

The invention discloses a preparation method of ferrous L-threonate, and relates to the technical field of organic chemical synthesizing.The preparation method comprises the steps that vitamin C serves as a raw material and is oxidized through hydrogen peroxide to obtain threonic acid, residual hydrogen peroxide is removed through high temperature, and the threonic acid reacts with ferrous carbonate under the nitrogen protection condition to generate the ferrous L-threonate; and filtering and concentrating under reduced pressure to obtain a ferrous L-threonate crude product, and recrystallizing and purifying the crude product to obtain a ferrous L-threonate pure product. The process has the advantages of good process stability, high purity of pure products, cheap and easily available raw materials, simplicity in operation, high safety, environmental friendliness and the like.

The application provides a preparation method of low-impurity vonerogefumate. The application provides a method for removing impurities A-E in the preparation of vonerogefumate, wherein vonerogefumate is reacted with hydrobromic acid to obtain vonerogefumate hydrobromide, and the method specifically comprises the following steps: (1) dissolving vonerogefumate and hydrobromic acid in a solvent; (2) cooling or directly precipitating a solid; and (3) separating to obtain vonerogefumate hydrobromide. The method can remove impurities A-E which are difficult to remove by a recrystallization refining method, and the method has good selectivity for impurities A-E. The application provides an impurity D, a preparation method thereof and application of the impurity D as an impurity control sample of vonerogefumate.

The application discloses a coal chemical industry wastewater purification and desalination recrystallization equipment, and particularly relates to the technical field of ceramic processing and polishing equipment. The application comprises a positioning plate, which is arranged above a purification tank and provided with two positioning plates. A driving mechanism is arranged between the two positioning plates. The driving mechanism comprises a moving frame, which is arranged on the left and right sides of the positioning plate. A transmission mechanism is arranged on the moving frame, which is used for putting flocculants into the tank water at different depths and stirring. A beating mechanism is arranged above the moving frame, which comprises a filter screen and is used for beating the filter screen. The driving mechanism further comprises a motor, which can uniformly disperse the flocculants to each part of the tank water, and can also add the flocculants to the tank water at different depths, so that the flocculants are more quickly combined with the wastewater, and the purification efficiency is further improved.

The utility model discloses a racemic p-hydroxyphenylglycine recrystallization device, and belongs to the technical field of chemical production devices and crystallization purification. The device comprises a decoloration and impurity removal kettle, a filter, a crystallization kettle, a centrifugal machine and the like, and has the innovation points that 1, a precise microporous membrane filter is additionally arranged in the decoloration and impurity removal process of the DL-hydroxyphenylglycine, and a rubber and plastic cotton heat preservation layer is additionally arranged on the outer surface of the microporous membrane filter; 2, a stirrer of the crystallization kettle is arranged into a double-layer structure, and an upper-layer stirring paddle is arranged into a rake shape; 3, an airflow control valve is additionally arranged between the crystallization kettle and the bottom valve; according to the technical scheme, the DL-p-hydroxyphenylglycine recrystallization device effectively solves the problem that tiny impurity points still exist after mother liquor is filtered, the problem that a pipeline is blocked due to temperature reduction in the midway of filtering, and the problem that a discharge valve of a crystallization kettle is easy to block; the device also has the characteristics of high production efficiency, high product purity and convenience in operation.

The invention relates to the technical field of fluorescent dye preparation, in particular to an organic fluorescent dye and a preparation method thereof.The preparation method comprises the following steps that m-diethylaminophenol and Meldrum's acid are catalyzed in an ethanol-water solvent through a supported catalyst and stirred to react in an oil bath, and an intermediate is obtained through acidification crystallization after cooling; and heating the intermediate, anhydrous potassium carbonate and ethyl iodoacetate in N, N-dimethylformamide under the protection of nitrogen to carry out alkylation reaction, and carrying out recrystallization, saponification hydrolysis and purification on the reaction liquid to obtain the organic fluorescent dye coumarin 343. The supported catalyst prepared by the invention shows good catalytic performance, stability and recoverability in the preparation reaction of the organic fluorescent dye.