75 results about "Crystallization Purification" patented technology

The application discloses a potassium fluorotantalate crystallization purification method, and relates to the technical field of tantalum hydrometallurgy and fluorotantalate crystallization purification. The method comprises the following steps: filtering a tantalum-containing fluorine acid solution, adding a potassium source and a tantalum-niobium separation type composite crystallization regulator, stirring and complexing, seed induction, controlled cooling crystallization, graded removal of the regulator, solid-liquid separation, and potassium fluoride containing fluorine acid washing to obtain primary purified potassium fluorotantalate crystals, and then redissolving the primary purified potassium fluorotantalate crystals in a fluorine-containing acid solution, correcting the K / Ta molar ratio, repeatedly regulating and crystallizing, graded removal of the regulator, washing, and drying to obtain high-purity potassium fluorotantalate. The regulator can reduce the entrainment of niobium impurities and reduce the residual amount of the regulator itself, thereby improving the purity of the product and the Ta yield.

The invention discloses a low-energy-consumption crystallization purification method of high-purity molten salt-grade potassium nitrate, and belongs to the technical field of purification of inorganic chemical materials. The method comprises the steps of raw material pretreatment directional impurity removal, multi-stage gradient crystallization, mother liquor graded circulation and low-temperature drying, in the raw material pretreatment stage, impurity concentration online detection and dynamic pH regulation are combined, a chelating agent, an oxidizing agent and an adsorption flocculant are added step by step, precise directional removal of metal impurities and suspended solids is achieved, and the product purity is improved; a multi-stage gradient crystallization process combining gradient temperature control and sectional controllable cooling is adopted, and the crystallization efficiency is improved in cooperation with a crystal form regulating agent; a mother liquor graded circulation and drying waste heat recovery system is matched, so that the mother liquor utilization rate is increased, and the production energy consumption is reduced.

The crystallization purification preparation system for 2, 6-dimethylnaphthalene comprises a suspension stirring crystallizer and a crystal filter, the suspension stirring crystallizer is connected to one end of the crystal filter, and the other end of the crystal filter is connected with a residual liquid tank and a static crystallizer; a mother liquid tank and a finished product tank are arranged on the first pipeline between the static crystallizer and the crystal filter; meanwhile, the residual liquid tank, the mother liquid tank and the static crystallizer are also respectively connected with a waste removal and discharge pipeline; wherein the suspension stirring crystallizer is connected with a cooling and heating all-in-one machine through a cooling and heating medium pipeline, and the static crystallizer is also connected with the cooling and heating all-in-one machine through the cooling and heating medium pipeline. According to the method, high-purity 2, 6-dimethylnaphthalene is obtained from low-value petrochemical raw materials by adopting a crystallization purification method.

The invention provides a preparation method for synthesizing lithium sulfide from industrial-grade lithium hydroxide and sodium sulfide, a preparation method for a solid electrolyte and a solid-state battery, and the preparation method for synthesizing lithium sulfide from industrial-grade lithium hydroxide and sodium sulfide comprises the following steps: dissolving an industrial-grade lithium hydroxide raw material, and sequentially carrying out oxidation, filtration, washing and drying to obtain lithium sulfide; sodium sulfide and a flocculating agent are added for precipitation and filtration, then sodium carbonate and barium nitrate are sequentially added for impurity removal and filtration, and a lithium hydroxide purified solution is obtained; reacting the sodium sulfide solid with dilute sulphuric acid to obtain hydrogen sulfide gas; hydrogen sulfide gas is introduced into the lithium hydroxide purification liquid for a reaction, and lithium sulfide slurry is obtained; evaporating, concentrating and crystallizing the lithium sulfide slurry, and centrifugally separating; and carrying out vacuum calcination on the crystal, and crushing to obtain lithium sulfide powder. Through oxidative conversion, chemical precipitation and crystallization purification, efficient and deep removal of impurities is realized, the problems that raw material components are complex and difficult to separate are solved, and the purity of lithium sulfide is improved.

This invention relates to the field of lithium battery technology and discloses a method for purifying lithium hexafluorophosphate by continuous flow crystallization. The method includes: (1) adding a first organic solvent to crude lithium hexafluorophosphate to dissolve it, preparing a saturated lithium hexafluorophosphate-organic solvent solution, filtering to remove insoluble matter, and obtaining a saturated lithium hexafluorophosphate solution; (2) feeding the saturated lithium hexafluorophosphate solution and the second organic solvent into a microchannel reactor for cooling using metering pumps, filtering the precipitated crystals, washing them with a cooled third organic solvent, and then vacuum drying. The lithium hexafluorophosphate precipitated by the method of this invention has high purity and stable quality, making it very suitable for industrial promotion and application.

The present application relates to a kind of preparation methods and systems of electronic grade dimethyl carbonate prepared from dimethyl oxalate, the method comprises the following steps: dimethyl oxalate is preheated and sent into decarboxylation reactor to carry out decarboxylation reaction, carbon monoxide, dimethyl carbonate and other light components are extracted from the top of decarboxylation reactor, and heavy components are extracted from the bottom of decarboxylation reactor;Carbon monoxide, dimethyl carbonate and other light components extracted are separated after gas-liquid, and liquid phase dimethyl carbonate is sent into rectifying column to carry out rectification purification;Electronic grade dimethyl carbonate product is obtained by crystallization purification in refrigeration crystallization device after rectification, and crystallization mother liquor returns rectifying column;Decarboxylation reactor is three-stage reaction tower, and rectifying section, reaction section, stripping section are sequentially from top to bottom.The present application is completely reacted by the design of three-stage decarboxylation reactor;Heavy components generated are extracted in real time, and catalyst stability is high;Electronic grade DMC is prepared by using rectifying column coupled with crystallization tower, and the yield of DMC is significantly improved.

The invention relates to composite ceramic, a preparation method thereof, aluminum segregation purification equipment and an aluminum segregation purification method. The preparation raw materials of the composite ceramic comprise silicon nitride, lithium titanate and silicon carbide. The composite ceramic is high in mechanical property, high in thermal conductivity and good in chemical stability and can be used as a crystallization rod in aluminum segregation and purification equipment for segregation, crystallization and purification of aluminum, and the crystallization rod made of the composite ceramic has longer service life compared with a graphite crystallization rod, so that the replacement frequency of the crystallization rod can be reduced, and the production cost is reduced. And the cost of aluminum segregation extraction is reduced.

This invention relates to an extraction method for improving the bioavailability of tartrate tylosin. The method includes subjecting tartrate fermentation broth to a single acid-dissolution and alkali-precipitation treatment, followed by static crystallization to obtain crude tartrate. This crude tartrate is then subjected to extraction and back-extraction steps, followed by decolorization and ultrafiltration to obtain refined tartrate. Finally, it is spray-dried to obtain tartrate tylosin. This invention optimizes the extraction process of tartrate tylosin by combining a single acid-dissolution and alkali-precipitation crystallization purification process with extraction and back-extraction processes, effectively improving the bioavailability of tartrate tylosin.

The invention discloses an efficient synthesis method of brexpiprazole, which comprises the following steps: taking 4-bromo-benzothiophene and N-Boc-piperazine as initial raw materials, under the protection of nitrogen, carrying out reaction by using a supported catalyst to prepare 4-Boc piperazine benzothiophene, and then carrying out acidolysis to obtain 4-piperazine benzothiophene hydrochloride; the method comprises the following steps: reacting 3, 4-dihydro-7-hydroxy-2 (1H) quinolinone with 1-bromo-4-chloro-butane to generate 3, 4-dihydro-7-(4-chlorobutoxy)-2 (1H)-quinolinone, and then converting the 3, 4-dihydro-7-(4-chlorobutoxy)-2 (1H)-quinolinone into 7-(4-chlorobutoxy)-2 (1H)-quinolinone; then condensing with 4-piperazine benzothiophene hydrochloride to obtain a crude product of brexpiprazole; and finally, crystallizing and purifying for multiple times to obtain high-purity brexpiprazole. According to the preparation method disclosed by the invention, 4-bromo-benzothiophene and N-Boc-piperazine are taken as starting raw materials, and high-purity brexpiprazole is prepared by optimizing selection of a catalyst and conditions of each step and through an excellent purification process.

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 discloses a high-purity synthesis method of 18-crown ether-6, which is characterized by comprising the following steps: S1, in an industrial microwave reactor provided with a special nano-material lining, uniformly mixing p-toluene sulfonic acid dihydric alcohol ester, dihydric alcohol, an alkaline substance and a composite solvent, and reacting at 0-40 DEG C for 0.2-5 hours to obtain a reaction product; in the reaction process, the reaction is promoted by virtue of the special property of the nano-material lining; and S2, after the reaction is finished, obtaining a high-purity target product 18-crown ether-6 through a specific post-treatment process. According to the method, the industrial microwave reactor provided with the special nano-material lining is adopted for reaction, the classical Williamson etherification reaction is accelerated through microwaves, the reaction time is greatly shortened, the reaction speed is greatly increased compared with that of a conventional method, meanwhile, the special purifying agent acetonitrile is added for crystallization purification, the purity of the product can be effectively improved, and the method is suitable for industrial production. The purity of the 18-crown ether-6 is not lower than 99.5%.

The invention belongs to the technical field of optical crystal preparation, and provides a magnesium fluoride crucible descending type directional crystallization purification method for ultraviolet optical crystal manufacturing. Magnesium fluoride raw materials are placed in a vacuum furnace to be subjected to desorption pretreatment, then the raw materials are fused, subjected to heat preservation and homogenized, first-process directional crystallization is achieved through descending displacement of a crucible relative to a hot area, a first ingot body is obtained, impurities are enriched towards the tail end along with the crystallization process, and only a local section of the enriched end is heated and remelted to form a controlled molten pool; the middle-section main body is kept in a solid state; the temperature gradient direction is reversed by switching the power ratio of a heating area, the molten pool is subjected to second-process directional crystallization in the opposite direction to form a second ingot body, the second ingot body is axially cut in a segmented mode, a middle purification section is reserved to serve as a high-purity raw material, and the middle purification section can be repeatedly executed in the same furnace to obtain a raw material section; according to the method, segregation enrichment and reverse ending are completed in a clean atmosphere, and the method is suitable for manufacturing magnesium fluoride crystals for ultraviolet optical elements.

The invention provides a waste salt treatment process and system based on a melt crystallization method, the waste salt treatment process is a process combining pulling crystallization, zone condensation and cold finger / cooling plate crystallization, and matrix salt is recovered from a chloride molten salt system containing strontium element and / or barium element and / or cesium element. The invention aims to solve the problems that the treatment scale and the product purity are difficult to consider at the same time, the volatilization loss is serious, and dual targets are difficult to realize under complex working conditions in the existing dry post-treatment waste salt melt crystallization purification technology. A waste salt melt crystallization purification technology which can adapt to complex working conditions, give consideration to high purification efficiency and high resource recovery rate and meet the large-scale treatment requirement is researched and developed, radioactive waste salt containing splitting elements is treated through process fusion, efficient purification of the waste salt is finally achieved, and the high removal rate and recovery rate are achieved.

The application belongs to the technical field of organic synthesis and specifically relates to a preparation process of high-efficiency taurine. The process specifically comprises the following steps: S1, raw material solution preparation and mother liquor threshold reuse; S2, construction of an aminolysis selective chemical environment; S3, aminolysis reaction; S4, deamination and clarification filtration; S5, segmented acidification-crystallization coupling; S6, crystal throwing and controlled cooling crystallization; S7, solid-liquid separation, washing and drying; and S8, mother liquor threshold detection and closed-loop reuse. The application constructs an aminolysis selective control, acidification-crystallization purification and mother liquor threshold reuse synergistic closed-loop process, stably controls a reaction system, dynamically determines an end point, and inhibits by-product generation from the source; segmented acidification and temperature-controlled crystallization are adopted to improve the purity of crystals and the first-time pharmaceutical-grade qualified rate; and the mother liquor is recycled according to a multi-index threshold access, thereby blocking impurity accumulation.

The invention relates to the technical field of fine chemical engineering, in particular to a preparation method of high-purity barium chloride. The method comprises the following steps: firstly, grafting an amino group on nano silicon dioxide and further synchronously introducing a hydrophobic chain and a phosphate group to prepare a difunctional surfactant with dispersion and impurity pre-adsorption functions for pretreating a witherite raw material; then calcining and dissolving with acid to obtain a crude solution, and sequentially carrying out multi-mechanism deep impurity removal and vacuum crystallization purification through barium hydroxide alkali adjustment hydrolysis, a targeted complexing agent and the like, so as to finally obtain high-purity barium chloride. According to the method disclosed by the invention, various impurities are efficiently and deeply removed through the cooperation of the whole processes of raw material pretreatment, targeted complexing and crystallization washing, the purity of the obtained barium chloride can reach 99.99% or above, the process flow is stable, and the yield is relatively high.

The application discloses a method for converting diacylated by-product into monoacylated product in the synthesis of fluoxastrobin, and belongs to the field of pesticides and intermediates. The method can effectively recover fluoxastrobin in a crystallization mother liquor and convert diacylated by-product, which is difficult to avoid in the synthesis process, into monoacylated product. The diacylated by-product and fluoxastrobin are close in polarity, and are difficult to remove by a conventional recrystallization method. In the application, the crystallization mother liquor containing the diacylated by-product and fluoxastrobin is dissolved in an organic solvent, a base is quantitatively introduced, the diacylated by-product is converted into monoacylated fluoxastrobin, the reaction solution is concentrated and recrystallized to purify, and the monoacylated product is obtained. In the application, the diacylated by-product is converted into the target product, and another by-product with stronger polarity is generated at the same time, which can be easily separated by recrystallization to obtain the target product with high purity. The process operation is simple, the conditions are mild, the separation yield is high, and the application has important significance for reducing three wastes, reducing cost and improving product quality.

This invention discloses a vacuum crystallization purification process for menthyl benzoate, comprising the following steps: S100, feeding; S200, cooling; S300, centrifugation. The parameter control process in step S200, cooling, specifically includes the crystallization temperature range, vacuum degree, methanol reflux flow rate, reflux methanol temperature, condenser medium, temperature rebound time, two-stage slow cooling method, multi-stage cooling method, and purity control of the menthyl benzoate raw material. This invention utilizes a rapid cooling method involving vacuum absorption and methanol reflux. Through precise temperature control, the system enters a transient stable state of crystallization before crystallization, where supersaturation and dissolution saturation are in equilibrium. Through two-stage slow cooling and multi-stage cooling stages, the system gradually enters a supersaturated solution state. Due to the precise control of the saturation-supersaturation-crystallization state, impurities cannot crystallize, thus achieving deep purification and obtaining a high-purity crystalline product.

The utility model discloses a stirring device and a crystallization purification system, and solves the technical problems of insufficient impurity diffusion and low segregation purification efficiency in the purification process of a crystallization method in the prior art. A stirring device comprises a support, two lifting mechanisms, a stirring mechanism, a water bath mechanism and a driving mechanism, and the stirring mechanism comprises a stirring column and a spiral piece arranged on the stirring column; the water bath mechanism is correspondingly communicated with the water bath inlet and the water bath outlet; the driving end of the driving mechanism is connected with the stirring column to drive the stirring column to rotate; under the condition that the lifting mechanism drives the stirring mechanism to ascend, the driving mechanism drives the stirring mechanism to rotate in a first direction; and under the condition that the lifting mechanism drives the stirring mechanism to descend, the driving mechanism drives the stirring mechanism to rotate in a second direction opposite to the first direction. According to the stirring column, under the combined action of the lifting mechanism and the driving mechanism, the vertical stirring speed and the rotating speed of the stirring column are controlled, and the stirring efficiency and the segregation effect are improved.

The invention relates to a 3-mercaptopropionic acid synthesis and crystallization purification integrated process based on a single solvent, which comprises the following steps: mixing solid alkali, a solvent and acrylic acid, and introducing hydrogen sulfide gas for reaction; after the reaction is finished, the unreacted hydrogen sulfide gas is absorbed by slightly excessive sodium hydroxide solution and is used for preparing sodium sulfide. Then, the reaction liquid is heated to the specified temperature, solid alkali is removed through washing while the reaction liquid is hot, and the obtained water phase is recycled after being concentrated and recrystallized. And carrying out reduced pressure distillation on the mother liquor from which the by-product is separated, and evaporating out the solvent to obtain the purified 3-mercaptopropionic acid product. According to the invention, by optimizing the process flow, the reduced pressure distillation temperature is reduced, the reduced pressure distillation time is shortened, the oxidation of the product at high temperature is effectively avoided, and the reaction yield is obviously improved. In the invention, the solvent has the functions of both a reaction solvent and a crystallization solvent, the yield of 3-mercaptopropionic acid is greater than or equal to 90%, and the product purity is greater than or equal to 99%.

This application provides a solvent-free subcritical water one-pot extraction and purification method for flavonoids from Sophora japonica buds, belonging to the field of green extraction technology and natural product processing. First, the raw material undergoes enzyme treatment. The Sophora japonica buds are loaded into a sealed stirred reactor; an acetate buffer solution with pH 4.4-5.0 and 0.07-0.15M is added, along with ascorbic acid as an antioxidant; nitrogen gas is purged to establish an inert atmosphere; then the enzyme preparation is added; incubation is performed; followed by subcritical water extraction to obtain crude flavonoids; finally, crystallization purification is carried out to obtain the final flavonoid product. This method eliminates the need for organic solvents, achieving integrated extraction and purification. Selective production of rutin or quercetin is achieved through simple parameter control. The production process is green and environmentally friendly, improving the yield and purity of flavonoids, reducing processing time, and lowering production costs.

The invention discloses a mixture purification and separation process and equipment based on melt crystallization, which comprises the following steps: feeding a crude product material into a crystallization purification device through a crude product storage tank to obtain a high-purity target crystal and a low-purity mother solution; the low-purity mother liquor is fed into a mother liquor storage tank to serve as a material to be purified again; the crystals with higher purity are subjected to countercurrent washing in the crystallization purification device, and impurities on the surface layer are melted and taken away to obtain a high-purity target crystal product; and melting the high-purity crystal to obtain a liquid product or granulating to obtain a solid product. A crude product is conveyed to a second crystallization area through a raw material pump and then is in contact with a cold material to be crystallized and separated out, and a solid falls to a third crystallization area; and the crystals passing through the washing area enter the melting area to be melted, and the melted liquid part is extracted, so that a high-purity product can be obtained.

According to the preparation method of the battery-grade iron phosphate precursor based on the stainless steel pickling waste liquid, high-value recycling of iron resources in waste water is achieved through the steps of pretreatment, precipitation reaction, purification and the like on the waste water, and the problem that resources are wasted severely in a traditional method is solved. Meanwhile, through precipitation reaction, washing and low-temperature crystallization purification operation, impurity ions in the iron phosphate precursor can be effectively removed, the purity of the product is improved, and the problem that the purity of the product is difficult to guarantee in a traditional method is solved.

The invention discloses a catalyst for preparing vinylene carbonate, a preparation method and a method for preparing vinylene carbonate.The method includes the steps that chloroethylene carbonate serves as a raw material, a catalytic reaction is carried out in a fixed bed to generate gas-phase vinylene carbonate, and the catalyst comprises a carrier and an active component, the carrier is a mixture of vinylene carbonate and polyvinyl carbonate, and the active components are chlorides or oxides of metals such as calcium, barium, nickel, magnesium, copper and the like. According to the method for preparing the vinylene carbonate, the vinylene carbonate crude product with the purity larger than 98% can be directly obtained through one-step reaction, and the vinylene carbonate product with the purity larger than 99.995% can be directly obtained through melt crystallization purification without rectification purification. The method for preparing vinylene carbonate disclosed by the invention is simple in process, simple in equipment, simple in catalyst preparation, low in cost and capable of realizing large-scale production, and has a wide application prospect.

The utility model discloses a deer blood crystal production and purification structure, which relates to the technical field of deer blood crystal production equipment and comprises a bottom plate, a support seat and a support frame, a purification and crystallization component is arranged at the top of the support frame, and a driving belt pulley, a belt and a driven belt pulley form closed rotating power. The rotating shaft and the mixing disc are driven to rotate to mix a solvent in the crystallization purification tank, the connecting pipe and the crystallization liquid inlet hopper are arranged to conveniently add a crystallization aid into the crystallization purification tank, crystal formation is promoted or crystal quality is improved, the solvent evaporator can promote solute to separate out crystals, and the ideal crystal size is obtained. Precipitated crystals can be conveyed into the centrifugal separation barrel through the conveying pipe and the control valve, the rotor is driven by the driving box to rotate, the crystals are separated from mother liquor through the centrifugal separation barrel, deionized water can be added into the centrifugal separation barrel through the solvent feeding hopper to clean the crystals, and therefore impurities adsorbed on the surfaces of the crystals can be removed.

The invention relates to the technical field of chemical purification, in particular to a continuous melt crystallization method for preparing ultra-pure 5-hydroxymethylfurfural through a direct contact cooling method, 5-hydroxymethylfurfural is purified through two-stage direct contact cooling crystallization, a low-temperature liquid coolant is used for being in direct contact with materials for heat exchange, the coolant is vaporized and recycled to a compressor for recycling, and the ultra-pure 5-hydroxymethylfurfural is obtained. The first-stage product is fed into a second-stage crystallization device, the steps are circulated, and finally the 5-hydroxymethylfurfural product with the purity larger than or equal to 99.99% can be obtained.The process is green, no solvent is added, no by-product is generated, the problem of scaling of a traditional cooling face is solved through direct contact heat exchange of the cooling agent, the problems that a traditional separation process is high in energy consumption, large in equipment investment and the like are solved, and industrial production is facilitated. According to the process, the purity of the product can reach 99.99% finally, and the technical barrier of the existing process is broken through.

The invention belongs to the technical field of thymol preparation, and particularly relates to a multi-stage alkali washing counter-current extraction and purification method for a thymol synthetic crude product. Comprising the following steps: preparing a thymol crude product through Friedel-Crafts alkylation reaction, diluting with an organic solvent, adding water and separating an oil-water phase to obtain liquid acid with relatively high concentration, carrying out alkali washing to obtain an alkaline phenate aqueous solution, layering multi-stage mixed oil and water, neutralizing, crystallizing and refining to obtain the thymol. According to the purification method, water washing is directly used, an acid catalyst which is high in concentration and easy to post-treat can be recycled with a small amount of water, the problem that the environmental protection pressure is large when thymol is synthesized through a liquid acid catalysis method is solved, a low-cost liquid phase method has a practical space, the technical threshold of synthesis and separation steps is lowered, and the method is suitable for industrial production. The industrial production of the thymol is facilitated.

The invention discloses a method for synthesizing high-purity super-crystal formamidine bromide (FABr), which is characterized in that the FABr is synthesized by means of anti-solvent addition and staged cooling, and the method comprises the following steps: (1) feeding for reaction; (2) extracting a crude product; (3) suction filtration and washing; (4) crystallizing and purifying; and (5) vacuum drying, through combination of a neutralization reaction and a recrystallization process, impurities such as metal ions and acetate ions can be effectively removed, the purity of a final product can reach 99.9% or above through verification, the method is short in process route and mild in reaction condition, the total yield can be stabilized to be 85% or above, the whole process is carried out at low temperature and in an inert atmosphere, thermal decomposition and oxidation of FABr are reduced, and the method is suitable for industrial production. The product has excellent thermal stability and storage stability, the FABr crystal obtained through temperature-controlled crystallization is uniform in size, easy to store and used for subsequent preparation of a perovskite precursor solution, used reagents are common, the cost is low, operation steps are simple, and industrial large-scale production is easy to achieve.

The invention discloses a proline bulk drug crystal refining method which comprises the following refining steps: step 1, taking purified water as a solvent, adding purified water into a dissolving tank, stirring, heating, then adding an L-proline crude product, and dissolving to obtain an L-proline crude product solution; step 2, adding activated carbon into the L-proline crude product solution, and sequentially carrying out constant-temperature decoloration, decarburization filtration and membrane filtration to obtain L-proline filtrate I; step 3, concentrating the L-proline filtrate I, then cooling and filtering to obtain an L-proline saturated solution, and pouring the L-proline saturated solution into a crystallizing tank; the invention relates to the technical field of medicines. In the refining process, any organic solvent is eliminated, so that the finished product has no solvent residue; the crystals are dried in a gradient boiling drying mode, and the finished product is granular white crystals and is attractive in appearance; the method has industrial large-scale production practicability; the method is high in yield and has good economic benefits.

The utility model relates to the technical field of sewage treatment, in particular to a benzyl benzoate static crystallization and purification device which comprises a container, the container is provided with a feed port and a discharge port, and at least three heat exchange pipelines are arranged in the container; the heat exchange pipeline comprises an inner pipe and an outer pipe, the outer pipe sleeves the outer side of the inner pipe, and the inner pipe and the outer pipe are coaxial; the outer wall of the inner pipe is thinner than the inner wall of the outer pipe, so that a gap is formed between the inner pipe and the outer pipe, the two ends of the gap are sealed, and water is contained in the gap; an inlet and an outlet of the inner pipe extend out of the container; an outlet of the inner pipe is communicated with the liquid storage tank; the device further comprises a switching valve. An outlet of the switching valve is connected to a liquid supply pipeline; the liquid supply pipeline is connected to at least three liquid supply branch pipes; the at least three liquid supply branch pipes are respectively communicated with inlets of inner pipes of the at least three heat exchange pipelines; two liquid inlets of the switching valve are respectively communicated with a cold liquid supply pipeline and a hot liquid supply pipeline; benzyl benzoate crystallization is more uniform, and purity and yield of benzyl benzoate crystallization purification are improved.

The invention provides a caprolactam purification method and application thereof. The purification method of caprolactam comprises the following steps: S1, carrying out alkali washing on a raw material benzene-hexane solution by using alkali liquor to obtain an alkali-washed benzene-hexane solution; s2, the benzene-hexane liquid obtained after alkali washing in the S1 is subjected to distillation and preliminary debenzolization, and benzene-hexane liquid obtained after preliminary debenzolization is obtained; s3, rectifying the benzene-hexane solution subjected to primary debenzolization obtained in the step S2 to obtain a caprolactam crude product rectified solution; and S4, recrystallizing the caprolactam crude product rectification liquid obtained in S3 to obtain caprolactam crystals. The caprolactam purification method is an efficient and green caprolactam rectification and crystallization purification method, can be used in a caprolactam-hexamethylenediamine process and can replace superior caprolactam, the cost is reduced, and the benefit is improved.