668results about "Crystallization plant arrangements" patented technology

The invention provides a sulfamic acid continuous crystallization production device and process, the sulfamic acid continuous crystallization production device comprises a filter box and a production box, the production box is fixedly connected to the upper surface of the filter box through bolts, the top end of the production box is provided with a feeding pipe, the middle part of the interior of the production box is provided with a partition plate, and the middle part of the partition plate is provided with a conveying pipe; a discharging pipe, a production reaction module and a filtering and cleaning module are arranged between the production box and the filtering box. According to the sulfamic acid continuous crystallization production device and the sulfamic acid continuous crystallization production process, in the sulfamic acid continuous crystallization production process, when sulfamic acid crystals are filtered out from mother liquor through the filter cartridge, purified water is sprayed into the filter cartridge through the spray head; and the sulfamic acid crystals can be quickly and uniformly washed to remove impurities through the filter cartridge which continuously shakes in a reciprocating manner in the rotating process, so that the continuous crystallization production efficiency of the sulfamic acid can be effectively improved.

The invention provides a continuous preparation system and method of pyroxasulfone. The continuous preparation system comprises a mixing device, a continuous oxidation reaction device, a continuous quenching device, a continuous devitrification device, a continuous solid-liquid separation device and a continuous drying device. Compared with intermittent preparation of pyroxasulfone, the continuous preparation system disclosed by the invention has the advantages that the reaction can be more stable, and the reaction temperature can be more accurately controlled, so that the problems of large heat release and high process risk in batch reaction can be effectively solved. Moreover, compared with a tank reactor, the continuous oxidation reaction device filled with the catalyst bed layer can improve the oxidation reaction rate, shorten the oxidation reaction time and improve the yield and selectivity of oxidation products.

The invention discloses a p-methyl benzyl chloride production process and a production system thereof, p-xylene side chains and chlorine are subjected to a gas phase substitution reaction under micro negative pressure and visible light catalysis to generate crude methyl benzyl chloride and hydrogen chloride, and 99.0% methyl benzyl chloride, a small amount of benzyl dichloride and 31% hydrochloric acid are respectively generated through rectification and absorption; the device consists of four working sections of chlorination, rectification, hydrochloric acid absorption and distillation. According to the method, the defects in the prior art are overcome, on one hand, chlorine is introduced, and an aromatic ring chlorination reaction is carried out under visible light catalysis; on one hand, a supported catalyst filler is arranged at the bottom of a chlorination tower, and a zeolite molecular sieve modified by long-chain alkylsilane and supported by metal salt is used as a catalyst to catalyze chloromethylation reaction, on the other hand, the hydrophobicity of the modified catalyst is obviously enhanced, and meanwhile, the density of acidic sites is not reduced; the contact opportunity of the catalyst and a reaction substrate is greatly increased, and the catalytic efficiency of the catalyst is improved.

The invention discloses a method for purifying p-dioxanone by coupling vacuum distillation with solution crystallization, which comprises the following steps of: firstly, removing light and heavy impurities from a p-dioxanone crude product in a vacuum distillation manner; and the rectified and purified p-dioxanone enters a crystallizer to be subjected to solution crystallization operation to obtain high-purity p-dioxanone, and crystallization mother liquor is returned to vacuum rectification after the solvent is removed.

The present invention relates to a three-phase methodology to obtain a highly concentrated, purified chemical component from plant material in an industrial setting. The three phases of the methodology of the present invention include Phase 1 : Preparing and solubilization, Phase 2: Separation and Salting and Phase 3: crystallization. The methodology results in dried composition purified from a plant material having at least 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, or 95% of the chemical component by weight.

Provided are methods of extracting lithium from a lithium containing solution, as well as the resulting compositions. The method includes supplying a lithium containing solution to a lithium capture step, the lithium capture step being operable to capture lithium from the lithium salt containing solution. The method further includes recovering lithium from the lithium capture step to produce a lithium rich stream. In especially preferred methods, the lithium capture step is performed to increase the lithium to sodium ratio above at least 1:1. Optionally, the lithium rich stream can be purified to remove divalent ions and borate ions. The lithium rich stream is then concentrated by supplying the lithium rich stream to a reverse osmosis step to produce a concentrated lithium rich stream.

The invention discloses a process and equipment for producing special melamine by a gas phase quenching method. The production process comprises the following steps: hot process gas from an outlet of a melamine reactor is in contact with cold process gas in a crystallizer, a generated solid A is discharged from the bottom of the crystallizer, and mixed gas enters a trap for gas-solid separation to obtain a solid B; the solid A is conveyed into a high-pressure collecting device A through high-pressure conveying gas A, it is ensured that the temperature of the high-pressure conveying gas A is higher than 120 DEG C in the conveying process, after gas-solid separation is conducted in the high-pressure collecting device A, the solid A is conveyed into a packaging device A through low-pressure conveying gas A, and it is ensured that the temperature of the solid A at the conveying tail end does not exceed 85 DEG C.

The invention belongs to the technical field of freeze concentration, and relates to a freeze concentration method, which comprises the following steps: freezing a dilute solution to obtain a solid or a solid-liquid mixture, crushing the solid or solid-liquid mixture obtained by freezing, or firstly separating the solid-liquid mixture and then crushing the solid, and adopting dry gas as an energy medium, and penetrating the crushed solid and transferring heat, and staged reserving the solution to realize freezing concentration of the dilute solution. The method improves the efficiency of freeze concentration and separation purification, is simple to operate, and can be conveniently applied to the fields of food, cosmetics, biological medicine, petrochemical industry, environment-friendly treatment and the like.

The invention relates to a method for removing organic oligomers in a saturated ammonium sulfate liquid system discharged by an acrylonitrile ammonium sulfate device crystallizer, belongs to the field of chemical waste liquid resource recycling, and particularly relates to a method for removing organic oligomers in a saturated ammonium sulfate liquid system discharged by an acrylonitrile ammonium sulfate device crystallizer. The invention aims to solve the technical problem that the ammonium sulfate polymer waste liquid discharged by the crystallizer of the existing acrylonitrile ammonium sulfate device affects the stable operation of the incinerator of the environment-friendly device. After being treated by the method, the amount of the recyclable ammonium sulfate liquid is 80-90%, the amount of the separated oligomer liquid is 10-20%, the concentration of the oligomer in the separated oligomer liquid is 70-80%, and the amount of ammonium sulfate in the separated and incinerated oligomer liquid is only 1-4.5% of the amount of ammonium sulfate in the original incineration liquid, so that the influence of ammonium sulfate on an incinerator can be greatly relieved or eliminated; and long-term stable operation of the incinerator device is ensured.

The invention provides an evaporative crystallization device and process for fluorine-containing high-salinity wastewater, and relates to the technical field of high-salinity wastewater treatment.The evaporative crystallization device for the fluorine-containing high-salinity wastewater comprises a support and an evaporation tank, and a first material opening used for communicating a stacking ring cavity with a material storage cavity is formed in an inner cylinder; a second material opening for communicating the material storage cavity with the material discharge cavity is formed in the first baffle plate; the heating assembly is in contact with and heats the wastewater to evaporate and discharge a wastewater solvent, a wastewater solute is gradually separated out to form crystals and moves towards the material stacking ring cavity, the first material opening is controlled to be opened, the second material opening is controlled to be closed, the crystals in the material stacking ring cavity enter the material storage cavity through the first material opening, and then the first material opening is controlled to be closed and the second material opening is controlled to be opened; the crystals in the material storage cavity enter the material discharging cavity through the second material opening, the crystals in the material discharging cavity are discharged through the first auger, the separated crystals can be continuously discharged without shutdown, meanwhile, the negative pressure environment in the evaporation tank is prevented from being damaged, and the working efficiency is improved.

The invention relates to the technical field of fertilizer processing, and provides a fluidized bed granulation device and a granulation method.The fluidized bed granulation device comprises a fluidized bed granulator, a cooler, a molten liquid conveying pump and a seed crystal making machine, and the molten liquid conveying pump is communicated with the fluidized bed granulator and the cooler through a first flow path; the molten liquid conveying pump is used for pumping molten liquid to the fluidized bed granulator and the cooler through the first flow path; the seed crystal making machine is respectively communicated with the fluidized bed granulator, the cooler and the molten liquid delivery pump through a second flow path, and is used for making the molten liquid pumped by the molten liquid delivery pump through the second flow path into seed crystals; and the seed crystal is conveyed to the fluidized bed granulator and the cooler through the second flow path. According to the invention, large-particle products with good roundness and good hardness can be produced without crushing of a crusher, and the product quality is improved.

The invention provides a system and a method for producing high-purity electronic-grade carbonic ester, and the system comprises a heterogeneous reaction section, a separation section and a crystallization section along the material flow direction, the heterogeneous reaction section is used for carrying out heterogeneous reaction on ethylene oxide and carbon dioxide to prepare carbonic ester; the separation section is used for separating materials from the heterogeneous reaction section and comprises a flash evaporation unit and a rectification unit in the material flow direction, and the flash evaporation unit comprises at least one flash evaporation tank; the rectification unit comprises at least one rectification tower, and the side-draw of the rectification unit is communicated with the feed port of the crystallization section; and the crystallization section is used for crystallizing and purifying the material mainly containing carbonic ester from the separation section. According to the method, high-purity ethylene carbonate used as a power battery can be obtained from the crystallization section, and crystallization mother liquor can be selectively returned to the separation section to be concentrated. The method can effectively improve product purity, reduce product chromaticity and reduce energy consumption, and can be applied to industrial production of carbonic ester.

In a general aspect, a carbon dioxide (CO2) removal system uses geothermal energy. In some implementations, a method to remove CO2 gas from a gaseous feed includes directing a gaseous feed to interact with an alkaline capture solution in a first gas-liquid contactor. A first portion of CO2 from the gaseous feed dissolves into the alkaline capture solution to form a CO2-rich alkaline capture solution. Steam is generated using heat from a geothermal heat source, and the steam heats the CO2-rich alkaline capture solution in a second gas-liquid contactor. A second portion of the CO2 is separated from the CO2-rich alkaline capture solution in the second gas-liquid contactor to form a CO2-lean alkaline capture solution. The CO2-lean alkaline capture solution is directed to the first gas-liquid contactor.

The invention relates to a device and a method for the continuous, controlled crystallization of metal salt crystals, in particular lithium carbonate crystals. These crystals can be produced on an industrial scale with high homogeneity.

The invention discloses a comprehensive utilization method of high-salinity wastewater produced by hydrometallurgical treatment of bastnaesite, which comprises the following steps: A, mixing alkaline wastewater and acidic wastewater, neutralizing and clarifying to obtain calcium fluoride and sodium chloride wastewater; b, mixing the sodium chloride wastewater with the precipitation wastewater, adding lime water in an aeration manner to adjust the pH value, hydrolyzing heavy metal ions in the wastewater, and performing solid-liquid separation to obtain filter residues and filtrate which is sodium chloride high-salinity wastewater; and C, adding oxalic acid into the sodium chloride high-salinity wastewater, stirring, standing, carrying out solid-liquid separation, pressurizing, concentrating, recovering hydrochloric acid, and crystallizing to obtain a crystal substance, namely a sodium chloride product. According to the method, fluorine in the wastewater is removed firstly, then the wastewater is recovered into wastewater containing sodium chloride, oxalate is dissolved into the high-salinity wastewater to separate out sodium oxalate and recover hydrochloric acid, so that the content of sodium chloride in the system is greatly reduced, and the recovery efficiency of sodium ions in the wastewater is improved.

The invention belongs to the technical field of freeze concentration, and relates to a freeze concentration method which comprises the following steps: combining a plurality of freeze concentration devices with a negative correlation principle between melting points and solute concentration according to a certain mode to form a multi-stage freeze concentration system; by utilizing the low-temperature advantage of the solution obtained during dissolution in each stage of freeze concentration, the energy use of the next stage of freeze concentration in the freezing link is reduced, and the energy use efficiency is improved, so that the freeze concentration effect and efficiency are improved; and meanwhile, the energy utilization efficiency can be further improved by utilizing the heat of the dilute solution raw material and the heat dissipation of the freeze concentration device.

The invention belongs to the technical field of brine extraction, and particularly relates to a process method and system for extracting iodine from calcium-magnesium-sodium type brine, the process comprises an iodine enrichment process and an iodine refining process, the first process comprises the following steps: firstly, removing organic matters and solid phase impurities in the raw material brine, then removing calcium ions, and then carrying out acidification and oxidation; finally, iodine-containing air and iodine-extracted brine are obtained through air blowing; meanwhile, after iodine-containing air is subjected to primary demisting and primary purification, alkali liquor is added for primary absorption and secondary absorption, and iodine-enriched liquid is obtained; and 2, acidifying the iodine enrichment liquid, separating out iodine crystals, separating the crystallized iodine from the mother liquor, adding purified water for washing, melting the crystallized iodine at high temperature, purifying and refining, and finally cooling and crushing to obtain the finished product iodine. The method provided by the invention fully realizes recovery and utilization of iodine resources, ensures the comprehensive utilization rate of the resources, absorbs free iodine in iodine-containing air twice by using the alkali liquor, avoids the use of sulfur dioxide, reduces the process risk, and improves the quality of iodine products.

The invention provides an ultrasonic-assisted gamma-aminobutyric acid crystallization particle size regulation and control method, which comprises the following steps: removing impurities and decolorizing gamma-aminobutyric acid-containing feed liquid, heating, stirring and concentrating to a nearly saturated state, then carrying out ultrasonic-assisted crystallization, cooling, aging and suction filtration to obtain coarse crystals, and finally washing and drying to obtain target crystals. According to the method, a synergistic process of raw material liquid pretreatment, evaporation concentration-ultrasonic-cooling coupling crystallization, aging and post-treatment is adopted, an ultrasonic cavitation effect is utilized to reduce a nucleation barrier, and a supersaturation degree precise control and gradient cooling strategy is combined, so that grain size refinement, obvious narrowing of distribution and effective inhibition of agglomeration of crystals are realized; the median particle size of the crystal can be controlled to be smaller than or equal to 200 microns, the particle size distribution span is smaller than or equal to 1.5, the agglomeration phenomenon is remarkably inhibited, the crystal form is kept stable, the crystal habit is complete and smooth, the crystal product quality and the process efficiency are remarkably improved, and the method has important industrial application value.

Provided is a method of recovering valuable materials that is a method of recovering lithium carbonate from a lithium-ion secondary battery, where the lithium carbonate has a boron content of less than 1 ppm and a calcium content of 100 ppm or less. The method includes a heat treatment step, a crushing and classification step, a slurry formation step, a wet magnetic separation step, an acid leaching step, a neutralization step, a neutralized cake solid-liquid separation step, a calcium carbonate crystallization step, a calcium carbonate solid-liquid separation step, and a calcium adsorption and removal step.

The invention discloses an adjustable crystallizer for fatty acid preparation, and relates to the technical field of fatty acid preparation, the adjustable crystallizer comprises a crystallization kettle and a kettle cover, a stirring shaft is arranged on the kettle cover, a jacket layer is arranged on the outer side wall of the crystallization kettle, a guide rod is fixed in the crystallization kettle, a ball body and an attachment cylinder slide on the guide rod, and an attachment plate sleeves the outer surface of the ball body. Air pipes are arranged in the crystallization kettle, a heat exchange gas medium is introduced into the air pipes, and a port of each air pipe is located below the corresponding attachment plate, according to the adjustable crystallizer for fatty acid preparation, due to the arrangement of a bubble heat exchange mode, pipelines with too many shapes do not need to be arranged in mixed liquid, and therefore the problem of crystal attachment cannot be generated; and bubbles directly exist in the mixed liquid, so that no other isolation materials exist, heat exchange can be more efficient, and heat exchange loss generated by pipelines in the heat exchange process can be reduced.

The invention relates to the technical field of acetaminophen crystallization, in particular to a multi-stage continuous cooling crystallization device and method for acetaminophen. The invention provides a multi-stage continuous cooling crystallization method for acetaminophen, which comprises the following steps: S1, at least five stages of continuous cooling crystallization are adopted, and circulating water with a set temperature is injected into a jacket of a crystallization kettle during each stage of cooling crystallization; wherein during the first several stages of crystallization, the difference between the initial temperature of the material entering the crystallization kettle and the initial temperature of the circulating water is 13-25 DEG C; and during the last crystallization, the initial temperature of the material entering the crystallization kettle is 30-35 DEG C. According to the multi-stage continuous cooling crystallization method, different water temperatures are adopted to carry out gradient cooling on the materials, so that the problems of non-uniform grain size and low purity caused by crystal explosion due to large temperature difference between the materials and a refrigerant and high cooling rate in the early stage of cooling are avoided.

The invention belongs to the technical field of coal chemical industry grey water treatment, and particularly relates to an advanced treatment method and system for coal chemical industry grey water circulating water. The method integrates pretreatment, complexing cracking, fractional crystallization and deep deamination, and is characterized in that a chelating structure of an organic phosphorus dispersing agent and calcium and magnesium ions is thoroughly destroyed through an advanced reduction-advanced oxidation combined process, target ions are released, and the core problems that hardness removal is hindered and phosphorus pollution is caused are solved; then, calcium and magnesium are respectively converted into calcium carbonate and magnesium ammonium phosphate particles for resource recovery by utilizing a secondary crystallization technology, so that the bottlenecks of high alkali liquor consumption and salt accumulation of a traditional high-pH magnesium ion precipitation method are broken through; and finally, the residual ammonia nitrogen is deeply removed by adopting a pollution-resistant PTFE hydrophobic membrane, so that the residual ammonia nitrogen is efficiently and stably removed, and the problem that a traditional polypropylene material membrane system is easy to pollute and block, easy to oxidize and difficult to apply to the field is solved.

The invention provides a process for recovering sodium sulfate, sodium carbonate and glaserite in alkali ash and removing chloride ions. The process specifically comprises the following steps: dissolving the alkali ash; sodium sulfate and sodium carbonate in the alkali ash solution are separated through hot crystallization; cooling, crystallizing and separating glaserite in the alkali ash solution; sulfate ions and carbonate ions in the alkali ash solution are separated from chloride ions; and further separating sodium sulfate, sodium carbonate, glauberite and the like in the alkali ash solution. Meanwhile, the invention provides a system for implementing the process. The system comprises an alkali ash dissolving unit, a main crystallization unit, a glaserite crystallization unit, a nanofiltration unit and other elements. According to the process and the system provided by the invention, on one hand, sodium sulfate and sodium carbonate in the alkali ash solution can be extracted, glaserite can be extracted at the same time, chloride ions in the solution are removed at the same time, and the discharge amount of mother liquor is reduced.

The invention relates to the technical field of wastewater treatment, in particular to a high-salinity wastewater low-temperature crystallization melting desalting device and method.The high-salinity wastewater low-temperature crystallization melting desalting device comprises a crystallization melting desalting device, a ton barrel and an infusion pump arranged on the crystallization melting desalting device, the infusion pump is slidably connected to the side wall of the crystallization melting desalting device, and a bottom frame is arranged beside the crystallization melting desalting device; the bottom frame is slidably connected with a containing frame used for containing a ton barrel, the containing frame is provided with two containing grooves matched with the ton barrel, the liquid inlet end of the infusion pump is fixedly connected with a fixing pipe, the side wall of the fixing pipe is fixedly connected with a side pipe, the side wall of the fixing pipe is provided with a conical sealing ring, and the upper side and the lower side of the outer wall of the side pipe are each provided with a top groove. Through the arrangement of the fixing pipe, the side pipe, the driving mechanism and other structures, rapid connection between the ton barrel and the crystallization melting desalter can be automatically achieved, meanwhile, an exhaust groove of the ton barrel can be automatically opened, connection between the ton barrel and the crystallization melting desalter can be rapidly released after extraction is completed, manual disassembly and assembly by workers are not needed, and the convenient performance of the device is greatly improved.

A process (1000) for producing a lithium salt (190) by treating a particulate lithium containing material containing lithium bearing minerals comprising pressure leaching (20) the lithium containing material with concentrated sulphuric acid to form a pregnant solution (22) containing lithium sulphate as a source of lithium for a selected lithium salt for production (190) and impurities; removing the impurities in a series of steps (30, 40, 50, 60, 70) including removal (70) of at least one sulphate compound contained in the pregnant solution, said at least one sulphate compound containing at least one of potassium and sodium; and producing the selected lithium salt (190) following impurity removal (30, 40, 50, 60, 70).

Black mass from disused lithium batteries is leached for recovery of various metals in a process that includes precipitation, solvent exchange, ion exchange, and salt splitting to create multiple product streams for recovery of pure value products. Most typically, the process is a closed-loop process and allows for production of metallic cobalt and nickel, EMD, and a high purity lithium hydroxide or carbonate product with minimal generation of waste streams.

The cooling crystallization production system comprises a crystallization unit, a product storage tank, a pipeline and a switching unit, the crystallization unit is composed of at least two parallel crystallizers, feeding ports of the crystallizers are connected with a discharging port of a distribution tank, and a discharging port of the distribution tank is connected with a discharging port of the product storage tank. Each crystallizer is a double-pipe heat exchanger, the shell pass of each crystallizer is a material flow path, and the tube pass of each crystallizer is a cold / hot medium flow path; the pipeline and switching unit is configured to selectively enable any crystallizer to be connected into a circulation loop, and in the circulation loop, materials circularly flow in the shell pass of the crystallizer through a circulation pump so as to achieve cooling crystallization. The crystallizer completing crystallization can be selectively switched to a discharging pipeline, and a heating medium is introduced into the tube pass of the crystallizer to melt crystals and then output the crystals into the product storage tank; compared with the prior art, a semi-continuous production mode is constructed, and the production cycle of unit products is shortened.

The invention discloses a crystallization device for sodium sarcosinate production, relates to the technical field of crystallization devices, and aims to solve the problems that when supersaturated liquid drops make contact with the wall surface of a low-temperature gas-liquid separator, water evaporation is intensified, the solubility of solute is further reduced due to temperature reduction, crystal precipitation is accelerated under the dual action, the supersaturated liquid drops are prone to being attached to the wall of a tank in the crystallization process, and the crystallization effect is poor. In order to solve the problems that the heat exchange efficiency is influenced by scaling of a tank wall, wall-adhered crystals cannot be recycled and the yield is reduced in the prior art, an evaporator is mounted on one side of a gas-liquid separator, a cyclone separator is mounted on the other side of the gas-liquid separator, an ultrasonic disperser is mounted on one side of the cyclone separator, a membrane filter is mounted on one side of the ultrasonic disperser, and a water outlet is formed in the other side of the membrane filter. A gas-liquid separator cleaning mechanism is mounted in the gas-liquid separator, a gas-liquid separator scraping frame is mounted at one end of the gas-liquid separator cleaning mechanism, and a membrane filter cleaning mechanism is mounted in the membrane filter.

The invention provides a production device and process for recovering electronic-grade phosphoric acid from waste etching liquid. The device comprises a raw material storage tank, a multi-stage filtration system, a phosphoric acid evaporation kettle, a purification system, a mixed acid storage tank and a neutralization reaction and crystallization system. The waste etching liquid enters an evaporation kettle after being subjected to multi-stage filtration to remove suspended solid particles, and phosphoric acid is separated from volatile nitric acid and acetic acid; and condensing the volatile acid into mixed acid for storage, and removing metal ions from the semi-finished phosphoric acid through a purification system to obtain the electronic-grade phosphoric acid. The mixed acid reacts with alkali to generate a mixed solution of sodium acetate and nitric acid, sodium acetate crystals are separated out through evaporation and concentration, a solid product is obtained after separation, nitric acid is obtained by condensing gas, and suspended particles and metal impurities are subjected to incineration treatment. Through the steps of filtering, negative-pressure evaporation, neutralization and crystallization and the like, the process realizes efficient recovery of electronic-grade phosphoric acid and byproducts of sodium acetate and nitric acid, and has the characteristics of high resource recovery rate and low pollution emission.

The invention relates to the field of chemical application, and discloses a device for preparing large-particle ammonium sulfate crystals through reduced-speed crystallization. Comprising a neutralization reactor, a settling separation tank, a pre-crystallization solution tank, a first-stage intermittent jacket crystallizer, a second-stage intermittent jacket crystallizer, a filter powder sieving device, an ammoximation tert-butyl alcohol tower reboiler, a heat exchanger group, a stirrer group and a centrifugal pump group, wherein the centrifugal pump group consists of a centrifugal pump I, a centrifugal pump II, a centrifugal pump III, a centrifugal pump IV and a centrifugal pump V; the invention further discloses a process for preparing the large-particle ammonium sulfate crystals through speed-reducing crystallization. The process comprises the following steps: adding rearrangement liquid from a caprolactam rearrangement system and gas ammonia into the neutralization reactor through an external circulation pipeline. By fully utilizing heat in a neutralization reaction and crystallization process and combining with a compound additive, a seed crystal and a speed reduction crystallization technology, an efficient two-stage series crystallization mode is realized, the generation of large-particle ammonium sulfate crystals is promoted, the crystal quality is optimized, the energy consumption is reduced and the production efficiency is improved.