545results about "Crystallization by component evaporation" patented technology

A ternary deep eutectic solvent (TDES) system for a biomolecule (for example, chitin) recovery from a biomass (for example, seafood waste), and the method of preparation of ternary deep eutectic solvent (TDES) system, and a process to differentiate / extract / recover biomolecules (such as chitin) from a biomass (such as seafood waste).

The invention discloses a low-cost and environment-friendly process for producing 1, 4-bis (4-fluorobenzoyl) benzene, and belongs to the technical field of Friedel-Craft reaction, fluorobenzene and paraphthaloyl chloride react to generate 1, 4-bis (4-fluorobenzoyl) benzene, after reaction quenching, filtering is performed to obtain a crude product 1, 4-bis (4-fluorobenzoyl) benzene and filtrate, and the 1, 4-bis (4-fluorobenzoyl) benzene is purified in a sublimation crystallization mode; standing and layering the filtrate in an inclined plate layering device, respectively treating an oil layer and a water layer, dehydrating a fluorobenzene layer in a dehydrating tower, and returning fluorobenzene; the water phase is firstly subjected to organic matter removal treatment, the obtained organic matter enters a fluorobenzene recovery device to be sleeved back, and the obtained water phase is a byproduct of crystallized aluminum chloride in an evaporative crystallization device. According to the process, the 1, 4-bis (4-fluorobenzoyl) benzene is produced in a sublimation crystallization mode instead of a solution crystallization mode, no waste solvent is generated, the waste solvent does not need to be recycled, the cost is low, organic matter removal and evaporative crystallization treatment is carried out on wastewater, organic matter recycling is carried out, crystalline aluminum chloride is produced as a byproduct, and wastewater and waste salt are not discharged.

The invention discloses an evaporative crystallization device for high-purity anhydrous sodium sulphate, and relates to the technical field of anhydrous sodium sulphate processing, and the evaporative crystallization device is characterized by comprising an evaporation tank and a spraying and scraping mechanism, the spraying and scraping mechanism is arranged on the evaporation tank and comprises a spraying pipe, a spraying head, a vertical shaft, a cross arm, a scraping plate and a driving assembly, the spraying pipe is rotationally connected with the evaporation tank, the spraying head is installed at the end, located in the evaporation tank, of the spraying pipe, a spraying opening of the spraying head faces the inner side wall of the evaporation tank, and the spraying pipe is fixedly connected with the vertical shaft; the vertical shaft is fixedly connected with a plurality of cross arms, the cross arms are fixedly connected with a scraper blade, and the scraper blade is in friction contact with the inner wall of the evaporation tank; the driving assembly drives the spraying pipe and the spraying head to rotate, when a solution sprayed by the spraying head makes contact with the high-temperature inner side wall of the evaporation tank, water in the solution can be rapidly evaporated, and therefore separation of sodium sulfate crystals in the solution is accelerated, and the evaporation and crystallization efficiency is effectively improved.

The invention provides a method and system for salt separation, evaporation and crystallization of printing and dyeing wastewater, and the method comprises the following steps: sequentially carrying out multi-stage synergistic pretreatment on textile printing and dyeing wastewater to remove suspended solids, degrade organic matters and reduce hardness; the pretreated wastewater is subjected to membrane salt separation treatment, and preliminary separation of salt is achieved through reverse osmosis pre-concentration and nanofiltration salt separation; and respectively carrying out evaporative crystallization treatment on the separated high-concentration salt solution to obtain high-purity sodium sulfate and sodium chloride products. According to the method, the salt recovery rate and the product purity are remarkably improved, the energy consumption and the operation cost are reduced, meanwhile, the problems that in traditional printing and dyeing wastewater treatment, salt is difficult to separate, and the crystallization purity is low are solved, and an innovative solution is provided for high-valued resource recovery of industrial wastewater.

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 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 belongs to the technical field of evaporative crystallization equipment, and particularly discloses low-temperature evaporative crystallization equipment which comprises a crystallization kettle and a lubricating oil tank. A rotating shaft is arranged in the crystallization kettle, two ends of the crystallization kettle are respectively provided with a bearing chamber, a communicating hole is arranged between the crystallization kettle and the bearing chamber, a bearing for supporting the rotating shaft is arranged in the bearing chamber, and a sealing device or a sealing mechanism is arranged between the rotating shaft and the communicating hole. A lubricating oil pipeline is arranged between the lubricating oil tank and the bearing chamber, a pressure balance pipeline is arranged between the lubricating oil tank and the crystallization kettle, a plurality of paddle wheels are axially arranged on the rotating shaft at intervals, and each paddle wheel is provided with a plurality of paddles annularly distributed around the rotating shaft. A material scraping device is arranged between at least one pair of paddles of the adjacent paddle wheels, and a slag discharging opening is formed in the crystallization kettle. The problems that in the prior art, materials are prone to being discharged through the bearing chamber, and spiral propelling blades hinder material flowing are solved. The evaporation crystallization efficiency and the condensate scraping effect are remarkably improved, the gas-liquid separation efficiency is optimized, and meanwhile air pollution is reduced.

A method of forming lithium carbonate from a lithium-bearing solution including:evaporating the lithium-bearing solution to precipitate a first group of impurities;removing the first group of impurities to form a first purified solution; andperforming a flash crystallisation step within a predetermined temperature range to crystallise a second group of impurities from the first purified solution;removing the second group of impurities from the first solution to form a second purified solution, wherein at least 90 wt % of lithium is recovered from the first purified solution; andreacting the second purified solution with a metal carbonate to form lithium carbonate of at least 90 wt % purity.

The invention belongs to the technical field of waste PET (Polyethylene Terephthalate) recovery, and particularly relates to a continuous production system and process for efficiently recovering and refining PTA (Purified Terephthalic Acid) from waste PET and application. According to the continuous production system and process for efficiently recovering and refining the PTA from the waste PET, through mutual cooperation of the enzymolysis unit, the first solid-liquid separation unit, the filter cake dissolving and decolorizing unit, the electrolysis unit, the second solid-liquid separation unit and the recrystallization unit, continuous production of'obtaining the refined PTA by taking the waste PET as a raw material 'is realized; besides, by adjusting the runner structure in the electrolysis assembly of the electrolysis unit, the situation of electrolysis interruption caused by the fact that TA generated by electrolysis is prone to being deposited on the surface of the anode plate is avoided, guarantee is provided for continuous proceeding of the whole degradation and recovery process, and the system and the process have important significance on efficient degradation and recovery of waste PET.

The invention discloses a preparation method of battery-grade lithium hydroxide monohydrate, which comprises the following steps: causticizing a lithium sulfate concentrated solution, freezing and crystallizing to obtain a frozen solution, precisely filtering the frozen solution, filtering by adopting an alkali-resistant nanofiltration membrane, collecting a penetrating fluid, and when the permeability of the alkali-resistant nanofiltration membrane is reduced, filtering by adopting an alkali-resistant nanofiltration membrane to obtain the battery-grade lithium hydroxide monohydrate. The alkali-resistant nanofiltration membrane is cleaned by lithium bicarbonate thermal decomposition mother liquor of a lithium carbonate production line, and all collected penetrating fluid is subjected to evaporative crystallization and centrifugal drying to obtain the battery-grade lithium hydroxide monohydrate. By adopting a method of nanofiltration membrane impurity removal and primary evaporative crystallization, the nanofiltration membrane impurity removal is used for replacing the primary evaporative crystallization in the prior art, so that the energy consumption can be effectively reduced, the production cost is saved, the Si content of the nanofiltration solution is lower than 3ppm and lower than that of the primary evaporative crystallization heavy solution, and the method can be used for preparing high-quality battery-grade lithium carbonate. The Si content of the prepared lithium carbonate is lower than 20 ppm.

The embodiment of the invention provides an evaporation system control method and an evaporation system, and relates to the technical field of control, the method is applied to a control system in an MVR evaporation system.The method comprises the steps that in response to a starting instruction, a feeding system is controlled to pump to-be-treated liquid into an evaporation crystallization system, and the real-time boiling point rise of the evaporation crystallization system is monitored; and determining to adopt an optimal recovery rate control mode or a boiling point rise control mode as a target control mode based on the real-time boiling point rise, and controlling the feeding system, the evaporative crystallization system and the water production system to treat the to-be-treated liquid according to a preset strategy corresponding to the target control mode, the frequency of the distilled water and the flow of the to-be-treated liquid pumped by the feeding system meet the corresponding recovery rate, so that the control intelligence and reliability of the MVR evaporation system are improved.

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 relates to the technical field of ammonia desulfurization, and in particular to an integrated device for promoting crystal growth, comprising a desulfurization crystallization tower, a steam generator is arranged on one side outer wall of the desulfurization crystallization tower, a steam transmission end of the steam generator is connected to a first steam transmission pipe, and one end of the first steam transmission pipe runs through the interior of the desulfurization crystallization tower, a discharge port is through-connected on the bottom outer wall of the desulfurization crystallization tower, and a slurry crystallization tank is arranged on one side outer wall of the desulfurization crystallization tower; in the ammonia desulfurization process of the invention, the waste gas is desulfurized in the desulfurization tower, and the solution is concentrated and concentrated in the desulfurization tower by using high-temperature steam as a heat source, so that the slurry in the desulfurization tower is crystallized and precipitated; in the process, a feed pump is operated to pump the slurry with fine crystals in the desulfurization tower into the slurry crystallization tank, and the fine crystal slurry is crystallized by separating a part of the solvent in the slurry crystallization tank in combination with slow stirring, thereby increasing the crystallization; the crystallization inside the tower and outside the tower are combined to effectively increase the crystallization.

According to the present invention there is provided processes for the recovery of lithium from end-of-life lithium-ion batteries and battery matter. A representative process resides in a process for separating lithium from lithium ion batteries before undertaking hydrometallurgical or pyrometallurgical processing, the process comprising: providing a black mass (BM) or shredded battery material (SBM) that includes cation and anion components; commixing the BM or SBM with an admixture that includes water and supercritical carbon dioxide; and separating an aqueous leachate and a lithium-leached BM or SBM, where the aqueous leachate includes a lithium carbonate and / or bicarbonate.

This disclosure provides an optimized, energy-efficient, and sustainable solution for continuous in situ bio-based chemical recovery by integrating high pressure reverse osmosis with extraction processes. These systems achieve higher recovery efficiency while reducing production costs and environmental impact.

The invention belongs to the technical field of magnesium desulfurization wastewater treatment, and particularly relates to a magnesium desulfurization wastewater evaporation concentration material transfer anti-crystallization blockage system which comprises an evaporation separator and crystallizers, a circulation pipeline is arranged between an inlet and an outlet of a material transfer pump, and a material transfer pipeline is connected between a material transfer regulating valve and the crystallizers. The circulating pipeline and the branch pipelines are respectively communicated with the material transferring pipeline through branch pipelines, and the circulating pipeline and the branch pipelines are detachable metal hoses; a steam inner pipe is arranged in the material transferring pipeline, a heat preservation layer is arranged outside the material transferring pipeline, and opening degrees of the material transferring adjusting valve and the steam adjusting valve are in linkage control. Compared with the prior art, the device has the beneficial effects that effective anti-blocking prevention and emergency treatment are carried out on materials which are long in material transfer pipeline, rapid in concentration and temperature change and easy to crystallize in multi-point material transfer, cooperative control over the temperature of the separator feed liquid and the temperature of the material transfer pipe feed liquid is achieved, and concentration and temperature monitoring is carried out on the output feed liquid; materials always flow in the material transfer pipeline, and continuous production operation is guaranteed.

The invention discloses a water pollution collaborative treatment device and a method for using the same. The device comprises a floating object collecting mechanism, a microbial purification mechanism, a plant purification mechanism and a suspended filtering mechanism which are arranged in a river channel and used in coordination with each other. The floating object collecting mechanism comprises a floating collecting support shell floating on the water surface, the upstream end of the floating collecting support shell is rotatably provided with a horizontally arranged chain driving wheel, the downstream end of the floating collecting support shell is rotatably provided with a horizontally arranged chain driven wheel, a collection driving chain is provided for transmission connection between the chain driving wheel and the chain driven wheel, and a plurality of floating object blocking rods are fixed to the outside of the collection driving chain. The invention has a highly efficient pollution treatment capability, can effectively remove various pollutants in water, such as suspended solids, organic matter, nutrients such as nitrogen and phosphorus, and harmful substances such as heavy metals, has targeted treatment means for different types of pollutants, and ensures that the water quality is significantly improved.

The invention relates to the technical field of evaporative crystallization, in particular to a potassium chloride solution evaporative crystallization device. Comprising an equipment frame; a bottom plate is fixedly mounted on the equipment frame, and an evaporation mechanism is arranged on the bottom plate; according to the evaporation mechanism disclosed by the invention, the separation part is used for stirring in the evaporation process of the potassium chloride solution so as to improve the precipitation efficiency of crystals, and meanwhile, the precipitated crystals can be filtered to the drying part in time, so that the crystals are effectively prevented from being excessively increased in the evaporation barrel, the flowability of the solution is kept, and the stirring and heating uniformity is also ensured; the problem that the mixing efficiency is reduced due to increase of the crystals is avoided, and the crystals in the drying part are heated and pre-dried through the suction part by utilizing steam heat generated by evaporating the potassium chloride solution, so that the utilization rate of energy is increased.

The invention discloses integrated MVR (Mechanical Vapor Recompression) evaporative crystallization equipment, and relates to the technical field of evaporative crystallization. Comprising a frame body which is fixedly connected with an evaporation shell, a separator and a crystallizer; the first plate is rotationally connected into the evaporation shell; the first plate is arranged in the evaporation shell, the second plate is arranged in the evaporation shell, heat exchange pipes which are arranged at intervals are fixedly connected between the first plate and the second plate, and the heat exchange pipes are spiral and are used for bearing the gravity of a liquid medium, so that the first plate and the evaporation shell rotate relatively. Torque is applied to the heat exchange pipe through the gravity of a liquid medium, so that the heat exchange pipe rotates, steam in the evaporation shell is disturbed, and the temperature of all positions in the evaporation shell is uniform; therefore, the evaporation degree of the liquid medium in each heat exchange tube tends to be the same (the scaling phenomenon caused by excessive evaporation of the liquid medium in each heat exchange tube is prevented), and the uniformity of crystal precipitation during subsequent crystallization is facilitated.

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.

Producing high purity lithium solution from a source brine containing at least 1 mg Li / kg brine, preferably 10 mg / kg, more preferably 25 mg Li / kg brine; treating the source brine, if necessary in pretreatment steps; processing the treated brine in a lithium adsorption step; after the adsorption step, desorbing the adsorbed lithium in a desorption step; after the desorption step, treating the desorption effluent in an enrichment step. Specified optional steps and new features can be used to increase lithium concentrations and purity.

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).

The invention relates to the technical field of production of electronic-grade chemical products, and provides a purification method of electronic-grade high-purity 1-hydroxyethylidene-1, 1-diphosphonic acid. The method provided by the invention comprises the following steps: a dissolving step: uniformly dissolving an industrial-grade hydroxyethylidene-1, 1-diphosphonic acid raw material; a filtering step: removing large particles from the industrial-grade hydroxyethylidene-1, 1-diphosphonic acid solution through a micro-filter, removing zwitterions through a zwitterion removal device, and removing micro particles through a nano-filter in sequence; a crystallization step: carrying out crystallization treatment on the HEDP solution from which the microparticles are removed to obtain an electronic-grade high-purity HEDP crystal; and a drying step: drying the electronic-grade high-purity hydroxyethylidene-1, 1-diphosphonic acid crystal. The method can meet the standard requirements of the industries of general semiconductors, aerospace, photoelectricity and the like, and realizes the production of electronic-grade HEDP from industrial-grade HEDP.

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.

Process for producing a salt comprising NaCl and / or KCl from the aqueous effluents from one or more organic peroxide production processes, said process comprising the following steps (a) ensuring the pH of the aqueous effluents to be in the range from about 1-5, (b) separating the effluents in a liquid organic layer and an aqueous layer, (c) removing the organic layer, (d) raising the pH of the aqueous layer to a value in the range from about 6-14, and (e) crystallizing the salt from the aqueous layer having a pH in the range from about 6-14.

The invention relates to the field of calcium gluconate evaporative crystallization equipment, in particular to a crystallizing tank for calcium gluconate crystallization production and a using method thereof.The crystallizing tank comprises an evaporative crystallization tank body, the evaporative crystallization tank body comprises a tank body, a stirring and uniform heating assembly is arranged on the inner edge of the tank body, and an adaptive adjusting assembly is installed on one side of the stirring and uniform heating assembly; a crystal transfer assembly is arranged at the middle part in the tank body; the stirring and uniform heating assembly is used for stirring the to-be-crystallized solution in the tank body to uniformly disperse heat; the adaptive adjusting assembly is used for adaptively adjusting the stirring and heat uniformizing assembly according to the evaporation progress; according to the crystal stirring device, the situation that the stirring work is easily affected in the later period that the crystals are continuously accumulated at the bottom in the tank body and become high can be avoided, and meanwhile the situation that the crystals are likely to collide with a stirring component along with flowing of a solution, and consequently the crystals are broken can be effectively reduced.

According to the low-energy-consumption evaporating crystallizer, a single driving motor is adopted, a rotating shaft rod is used for simultaneously driving a scale scraping assembly arranged in an evaporating cylinder to conduct dynamic scale scraping and solution stirring, one end of the rotating shaft rod passes through a first transmission mechanism and a linkage shaft, and the other end of the rotating shaft rod is driven by a second transmission mechanism. A spiral separation assembly in the gas-liquid separation tank is driven by the direction conversion mechanism to rotate at a high speed so as to strengthen gas-liquid separation; and the other end of the discharging pipe drives a discharging assembly in the discharging pipe to rotate through a second transmission mechanism, so that discharging blockage prevention and negative-pressure deslagging are realized. Through a single power source, cooperative linkage of five functions of scale scraping, stirring, separation, blocking prevention and slag discharging is achieved, the structure is compact, the problems that traditional equipment is serious in scaling, poor in gas-liquid separation effect and prone to blockage during discharging are effectively solved, and meanwhile energy consumption of the equipment is remarkably reduced.

The invention relates to the field of desulfurized gypsum, and provides a process and a system for recycling desulfurized gypsum in a coal-fired power plant. The process comprises the following steps: 1) adding water into desulfurized gypsum to prepare slurry, reacting with ammonium bicarbonate to obtain a solid-liquid mixture containing calcium carbonate and ammonium sulfate, and separating into a liquid phase and a solid phase; 2) carrying out three-stage countercurrent washing on the solid phase to obtain calcium carbonate, directly adding water into the calcium carbonate to prepare slurry without drying, and recycling the slurry for gypsum process desulfurization; the washed water is reused in the slurry in the step 1); 3) adjusting the pH value of the liquid phase to 4.5-5.5, performing evaporative crystallization to obtain pure ammonium sulfate crystals and ammonium sulfate mother liquor, and returning the ammonium sulfate mother liquor to the liquid phase in the step 1); steam condensate water generated in the evaporation process is used for three-stage countercurrent washing, and steam generated in the evaporation process is used for drying pure ammonium sulfate crystals. The invention further provides a corresponding system. The whole process / system realizes continuous production operation of resource utilization of the desulfurized gypsum, and is simple to operate and good in production stability.

The invention relates to the technical field of ammonium dihydrogen phosphate preparation, and discloses a high-purity ammonium dihydrogen phosphate crystallization device and a method thereof.The high-purity ammonium dihydrogen phosphate crystallization device comprises a first-stage crystallization system, a first-stage centrifugal separation system, a second-stage crystallization system and a second-stage centrifugal separation system which are connected in series. The primary crystallization system comprises a crystal elimination heater, a crystal elimination mixer, a bag filter and a DTB flash cooling crystallizer which are connected in sequence, and is used for primarily purifying a concentrated solution; the primary centrifugal separation system is used for separating primary crystals; the second-stage crystallization system comprises a crystal dissolving tank, an OSLO cooling crystallizer and the like, and deep crystallization is carried out after the first-stage crystal is dissolved; the secondary centrifugal separation system is used for separating secondary crystals; through two-stage crystallization coupling, mother liquor graded circulation, a unique gradient washing process and active impurity control, efficient and continuous production of battery-grade ammonium dihydrogen phosphate with wet-process phosphoric acid as a raw material is realized, the product purity is high, the process flow is simplified, the cost is low, and the system operation is stable.