2398results about "Liquid solutions solvent extraction" patented technology

The invention provides a method for preparing VOSO4 electrolyte through gas enhanced reduction and reverse extraction, which comprises the following steps: adding an extraction inhibitor into an acidic vanadium-containing solution, stirring and reacting to obtain a vanadium-containing solution, the extraction inhibitor being phosphoric acid and / or a phosphoric acid compound; adjusting the pH value of the solution to 0.5-3.0 by using sulfuric acid, mixing with an organic phase, extracting, and separating liquid to obtain a vanadium-loaded organic phase; washing the vanadium-loaded organic phase with dilute sulfuric acid; a stripping agent and the vanadium-loaded organic phase are mixed for stripping, meanwhile, gas is introduced for strengthening the stripping process, and a no-load organic phase and a vanadium electrolyte are obtained; and the vanadium strip liquor is subjected to galvanic pile electrolysis adjustment, and the vanadium electrolyte with the valence state meeting the standard is obtained. The invention provides a novel process for directly preparing the vanadyl sulfate electrolyte through gas reinforced reduction, and the novel process has the advantages of being simple in process, easy to operate, low in cost and environmentally friendly.

A method comprises planarizing a substrate material with a functionalized chemical planarization pad. The functionalized chemical planarization pad includes a plurality of functional groups bonded to a material of the pad. The functional groups are configured to chemically react with the substrate material such that a portion of substrate material bonds to the functional groups. The pad is regenerated by applying a regeneration solution configured to break bonds between the functional groups and substrate material bonded to the functional groups to form removed material. The removed material is complexed in a dissolved complexing agent to form dissolved material in an effluent phase.

Methods for making high-purity LiFSI salts and intermediate products using one, the other, or both of a reactive-solvent removal / replacement method and an LiFSI purification method. In some embodiments, the reactive-solvent removal / replacement method includes using non-reactive anhydrous organic solvents to remove and / or replace one or more reactive solvents in a crude LiFSI. In some embodiments, the LiFSI purification method includes using anhydrous organic solvents to remove impurities, such as synthesis impurities, from a crude LiFSI. In some embodiments, crude LiFSI can be made using an aqueous-based neutralization process. LiFSI salts and products made using methods of the disclosure are also described, as are uses of such salts and products and electrochemical devices that include such salts and products.

The invention discloses a laterite nickel ore leachate extraction tower which comprises an extraction tower body, a heavy phase feeding mechanism, a light phase feeding mechanism, a baffle mechanism and a gas distribution device, the extraction tower body comprises a tower body, a containing cavity is formed in the tower body, and an upper clarifying groove is formed in the top of the tower body; the baffle mechanism comprises at least one movable baffle arranged in the tower body and a lifting driving piece, and through holes are densely distributed in the movable baffles. A heavy phase and a light phase are promoted to be mixed in an air floatation mode, and meanwhile, the lifting driving part drives the movable baffle to move up and down, so that the movable baffle is always located in the light phase in the tower body and located in a preset height range above an interface of the light phase and the heavy phase. When a heavy phase upwards penetrates through each through hole in the movable baffle, the heavy phase is dispersed into small liquid beads, so that the heavy phase is in full contact with a light phase above, the mixing effect is improved, and the extraction efficiency is improved.

The invention relates to the technical field of liquid-liquid homogeneous microextraction, in particular to a method for microextraction analysis of perfluorooctanoic acid by using a switchable eutectic solvent. Comprising the following steps: step 1, mixing a hydrogen bond acceptor and a hydrogen bond donor according to a set proportion value, and stirring and mixing at a set temperature value to obtain a eutectic solvent; step 2, filtering the water sample through a water-based filter membrane, then adding a set amount of deep eutectic solvent, dropwise adding an alkaline solution, carrying out full vortex mixing through a mixer, and then adding an acidic solution to form an emulsion; according to the method, the high selectivity of the green solvent with a specific structure on perfluorooctanoic acid and the characteristic that the solvent is switched between hydrophilic and hydrophobic forms are utilized, so that the microextraction time is shortened, and the impurity removal and enrichment effects are enhanced. The method is simple and convenient to operate, green, environment-friendly, low in cost and good in effect, has the advantage of efficiently and rapidly pretreating the batch small-size complex matrix sample, and has a relatively good application prospect.

Described herein are methods of recovering lithium from dilute lithium sources. The methods include extracting lithium from an extraction feed using direct lithium extraction in an extraction stage to yield a lithium intermediate, performing one or more concentration operations, each concentration operation concentrating an input stream to yield an output feed, wherein the input stream is obtained from the lithium intermediate and / or the extraction feed is obtained from the output feed. At least one of the concentration operations includes a membrane separation operation having a plurality of reactors in series each having a semi-permeable membrane, such as a counter-flow reverse osmosis operation. Methods may also include generating a low TDS stream as a permeate from any of the one or more concentration operations, wherein the low TDS stream is recycled or used as fresh water.

The invention relates to the technical field of fruit and vegetable fermentation polyphenol extraction, and discloses a fruit and vegetable fermentation polyphenol extraction device and method.The fruit and vegetable fermentation polyphenol extraction device comprises a reaction tank, the reaction tank is used for fruit and vegetable fermentation polyphenol extraction, and a fermentation extraction control mechanism is rotationally arranged in the middle of the reaction tank; the device comprises a reaction tank, the top end of the reaction tank is fixedly provided with a positioning shaft, one side of the reaction tank is fixedly provided with a fermentation extraction lifting control mechanism, the bottom end of the fermentation extraction lifting control mechanism is fixedly provided with a rotation control mechanism, and the output end of a first motor fixed to the top end of the reaction tank drives the positioning shaft to rotate rapidly in the forward direction; a rotary aeration effect is achieved at the bottom end of the fruit and vegetable liquid in cooperation with rotation of the communicating frame, so that fruit and vegetable fermentation liquid and air are fully mixed, it is ensured that microorganisms in the fruit and vegetable liquid can obtain enough oxygen to conduct normal metabolic activity, and an extracting solution enters the inner wall of the reaction tank through an extracting solution feeding pipe by adopting the same method; the extracting solution and the fruit and vegetable liquid are fully mixed by alternately pumping the extracting solution and the gas.

To provide a method for recovering oil from an oil-containing waste liquid, enabling efficient separation and recovery of oil from the oil-containing waste liquid through a solvent extraction method.SOLUTION: The method for recovering oil from an oil-containing waste liquid includes: an extraction step for extracting an oil-containing waste liquid using a solvent, thereby transferring oil in the oil-containing waste liquid to the solvent; a separation step for separating the solvent including the extracted oil and the waste liquid from each other; and an oil recovery step for separating and recovering the oil from the separated solvent-containing oil. In the method for recovering oil, the solvent is n-hexane, an oil concentration in the oil-containing waste liquid supplied to the extraction step is 1,000-5,000 mg / L, a volume ratio (solvent / waste liquid ratio) of the solvent to the oil-containing waste liquid is 0.01-0.05, and the oil concentration in the solvent containing the oil separated in the separation step is 4 mass% or more.SELECTED DRAWING: Figure 1

The invention relates to the field of ginsenoside extraction, in particular to a device and method for removing a plasticizer in a ginsenoside extract, and the device comprises a roll-over stand, a removal cabin and the like. According to the equipment and the method for removing the plasticizer in the ginsenoside extract, the filtering assembly and the adsorption resin blocks are distributed in the removal cabin in the vertical direction, so that fine filtering treatment and adsorption removal treatment of a ginsenoside extract solution are completed in sequence; and in addition, the filter assembly and the plurality of adsorption resin blocks can be subjected to backwashing treatment in a mutually separated state, so that the overall treatment process steps of the backwashing treatment work are reduced on the basis of ensuring that efficient backwashing treatment is synchronously performed on the filter assembly and all the adsorption resin blocks. The defects that multiple treatment devices need to be used in multiple filtering treatment and ion adsorption treatment processes of the ginsenoside extract solution, the plasticizer removal treatment efficiency is affected, and the plasticizer removal treatment period is delayed are overcome.

To provide an extractant for selectively extracting lithium salt, a method for recovering lithium salt, and a method for producing lithium salt.SOLUTION: A lithium salt extractant comprises at least one selected from a group consisting of a compound represented by a general formula (1) and a compound represented by the general formula (2) (where X1, X2, X3 and X4 independently represent an oxygen atom, a sulfur atom, a sulfinyl group, a sulfonyl group, a carbonyl group, or an imino group).SELECTED DRAWING: None

The invention discloses an organic extraction device for preparing an organic framework material, and relates to the technical field of extraction devices. Comprising an extraction tank, the extraction tank is provided with an upper feeding port, a lower feeding port, an upper discharging port and a lower discharging port, and fixing rings distributed in a linear array mode are installed in the extraction tank; the fixed shell is rotationally connected to the extraction tank; the plurality of first telescopic shells and the plurality of second telescopic shells are embedded in the fixed shell; the first turntable is in limited sliding connection with the fixed shell; and the second turntable is connected to the fixed shell in a limiting and sliding manner. By detecting the concentration of an organic component in a stock solution, when the concentration of the organic component is increased, the distance between the first turntable and the second turntable and the fixed ring is reduced, so that the flow area of liquid in the extraction tank is reduced, a higher shearing force is generated when the solution flows, the dispersion degree of liquid drops of the solution is increased, and the extraction efficiency is improved. The mixing speed of the stock solution and the extractant is accelerated, and the mass transfer efficiency is improved.

The invention discloses a method for separating iron and lithium in a lithium iron phosphate iron salt leaching solution and recycling iron phosphate, and belongs to the technical field of waste lithium battery recycling. The method comprises the following steps: constructing a bis (2-ethylhexyl) phosphate and trioctyl decyl tertiary amine mixed extraction system for selective extraction of Fe < 3 + >, adopting phosphoric acid for reverse extraction, recycling phosphoric acid reverse extraction liquid, preparing iron phosphate and the like. According to the method, efficient enrichment of Fe < 3 + > and efficient elution of Fe < 3 + > from a loaded organic phase are realized. The purity of the raffinate Li solution is relatively high, so that the subsequent preparation of battery-grade lithium carbonate is facilitated. The strip liquor can be recycled for multiple times, an iron intermediate is precipitated through pH adjustment, and the FePO4 product can be finally prepared through washing, aging and high-temperature calcination. The method is high in extraction selectivity, recyclable in process and mild in operation condition, has good separation effect and resource utilization efficiency, and is suitable for popularization and application of a Fe / Li separation process in lithium battery recovery.

The invention discloses a liquid-liquid reactor based on hydrodynamic cavitation, and belongs to the field of liquid-liquid reaction of chemical production, medicine production, wastewater treatment and the like. The liquid-liquid reactor comprises a chamber A provided with a first top surface and a first bottom surface, the inner diameter of the first bottom surface is gradually reduced from top to bottom, and a first arc transition section is arranged between the first top surface and the first bottom surface; a tangential leading-in first liquid inlet pipe is arranged above the chamber A; the chamber B is a flat disc-shaped chamber; the chamber B is provided with a second top surface and a second bottom surface; the chamber B is provided with a second liquid inlet pipe which is tangentially guided in; a second arc transition section is arranged between the cavity A and the cavity B; a third arc transition section is arranged between the second top surface and the second bottom surface; a liquid outlet pipe is arranged in the center of the cavity A, and a Venturi tube structure is arranged in the liquid outlet pipe; a flow guide piece is arranged in the center of the cavity B; the outer diameter of the flow guide piece is gradually reduced from bottom to top; and the flow guide piece is provided with an end part which is inserted into the liquid outlet pipe. According to the ultrasonic cavitation device, the defects that ultrasonic cavitation equipment adopted in production at present is higher in energy consumption and smaller in equipment size amplification are overcome, and the cavitation equipment is changed from research to industrialization.

The invention provides a coal chemical industry wastewater deoiling extraction agent and a preparation method and application thereof, and the coal chemical industry wastewater deoiling extraction agent comprises at least one of petroleum ether, aromatic hydrocarbon compounds and acid ester organic compounds. According to the coal chemical industry wastewater deoiling extraction agent, at least one of petroleum ether, aromatic hydrocarbon compounds and acid ester organic compounds serves as the extraction agent, the extraction capacity of physical extraction is high, the coal chemical industry wastewater deoiling extraction agent has the deoiling and dust removal functions when being used for treating coal chemical industry wastewater, and efficient treatment of oil dust in wastewater can be achieved; secondary pollution such as oily sludge and scum is not generated; meanwhile, the extractant is good in regeneration performance and high in recovery rate, and has the advantage of being repeatedly used after being regenerated; in addition, raw materials such as acid ester organic matters are low in price, safe, stable, wide in source and small in corrosion to equipment, so that the maintenance cost of the equipment is reduced, and the wastewater treatment cost is reduced to the greatest extent.

The invention discloses a passive multi-stage countercurrent micro-extractor and an extraction method of the passive multi-stage countercurrent micro-extractor. Wherein in the passive multi-stage countercurrent micro-extractor, each stage of micro-extractor is internally provided with a clarification chamber, and the clarification chamber comprises an upper chamber and a lower chamber; the transfer channels are distributed between every two adjacent stages of micro-extractors; the interface adjusting channels are distributed between every two adjacent stages of micro-extractors, between the first-stage micro-extractor and the post-extraction light phase collecting pipe and between the last-stage micro-extractor and the post-extraction heavy phase collecting pipe, and the resistance of the interface adjusting channels is far greater than that of the transfer channel; the heavy phase feeding pipe is connected with the primary micro-extractor; the light phase feeding pipe is connected with the final-stage micro-extractor; the extracted heavy phase collecting pipe is connected with a light phase feeding pipe; and the extracted light phase collecting pipe is connected with the heavy phase feeding pipe. The device has the advantages of no mechanical movable part, small volume, countercurrent operation, high mass transfer efficiency and easiness in amplification, and is particularly suitable for extraction and separation of dangerous mixtures.

The invention discloses an extraction tower, which comprises a tower body, a main shaft, a reciprocating lifting member, an autorotation member, a motor and a movable sieve plate group, the main shaft is rotatably arranged in the tower body, the main shaft and the tower body are coaxially arranged, the reciprocating lifting member is fixedly installed on the top of the main shaft, the reciprocating lifting member is used for enabling the main shaft to do reciprocating lifting motion, and the autorotation member is used for rotating the main shaft. The top and the bottom of the rotation part are fixedly connected with the main shaft and the bottom inner wall of the tower body respectively, the rotation part is used for enabling the main shaft to rotate, and the multiple movable sieve plate sets are evenly distributed outside the main shaft. The device not only can oscillate and scatter a liquid material in the vertical direction, but also can stir and scatter the liquid material in the horizontal direction, double multi-stage dispersion operation is achieved, the solvent liquid material mixing and contacting effect is improved, and the solvent liquid material contacting degree is guaranteed.

The invention aims to provide a device and method for extracting iron from red mud and preparing iron oxide red, and belongs to the technical field of resource utilization, hydrochloric acid is adopted to leach iron element in the red mud, and a ferric chloride solution is separated from leachate through an extraction process. And then, carrying out alkali precipitation, washing and firing to prepare the high-purity iron oxide red. By using the method disclosed by the invention, the iron resource in the red mud can be recycled, so that the dual purposes of resource utilization and environment-friendly treatment are achieved.

The invention relates to a method for producing industrial-grade phosphoric acid from wet-process phosphoric acid raffinate acid, and belongs to the technical field of wet-process phosphoric acid. The technical problem to be solved by the invention is to provide a low-cost method for producing industrial-grade phosphoric acid from wet-process phosphoric acid raffinate. The method comprises the steps of pretreatment, metal ion extraction, pretreatment, phosphoric acid extraction, washing, phosphoric acid reverse extraction, concentration and the like, and finally industrial-grade phosphoric acid is obtained. The method adopts the raffinate acid as the raw material to prepare the industrial grade phosphoric acid, perfects and improves the wet-process phosphoric acid purification process, can utilize the original production equipment of a phosphorus purification enterprise, does not need to add new equipment, and is low in production cost. According to the method, phosphoric acid loss is avoided, all extracting agents can be recycled, associated metal elements in the raffinate acid can be recycled in a cascade classification mode, and cost is saved. The method is high in extraction efficiency, the content of metal impurity ions in the obtained product phosphoric acid is low, and the requirement of industrial grade phosphoric acid is met.

The invention provides a method for producing carboxyl magnetic beads based on industrial solid waste, and relates to the technical field of carboxyl magnetic bead preparation, and the method comprises the following steps: preparing a saturated solution from ferrous sulfate solid waste; removing heavy metal impurities in the saturated solution by using a mixed extraction agent through an extraction method to obtain a ferrous ion crude product; synthesizing the ferrous ion crude product through a hydrothermal method to obtain ferroferric oxide particles; carrying out hydroxyl coating treatment on the ferroferric oxide particles to obtain hydroxyl coated particles; and carrying out carboxyl coating treatment on the hydroxyl coated particles to obtain the carboxyl magnetic bead material. Ferroferric oxide is produced by taking ferrous sulfate solid waste as a raw material through a hydrothermal method, then separation is carried out through a magnetic field, the separated ferroferric oxide is modified with a silicon hydroxyl coupling agent, the required iron oxyhydroxide magnetic beads are directly obtained, waste resources are utilized in an environment-friendly mode, the production cost is reduced, and the method is suitable for industrial production. And the great potential of improving the product quality and functionality is achieved.

The utility model discloses a circulating extraction tank, which belongs to the technical field of chemical equipment and comprises a tank body. A stirring assembly is further included, the stirring assembly comprises a stirring rod, the stirring rod is arranged in the tank body, the stirring rod is fixedly connected with the bottom of a rotating shaft, and the top of the rotating shaft is rotationally matched with the tank body; the device further comprises a filling assembly. The filling assembly comprises an extraction cylinder. The extraction barrel, the air cylinder and other structures are matched for use, the structure is simple, convenience and practicability are achieved, an extraction agent in the solution box can be quantitatively extracted, an operator can conveniently control the amount of the extraction agent added into the tank body, the extraction effect is guaranteed, meanwhile, the use amount of the extraction agent can be reduced, and therefore the cost is reduced, and the practicability is high. And the liquid extraction assembly is matched for use, so that an extracted solution can be extracted, an extracting agent is conveniently added again for cyclic multi-time extraction, and the extraction effect is greatly improved.

The utility model provides a wet-process phosphoric acid extraction device. A liquid outlet hole, a first mounting hole and a second mounting hole formed in an extraction tank of the wet-process phosphoric acid extraction device are all communicated with an extraction cavity, the liquid outlet hole is arranged close to the top of the extraction tank, and an extraction agent inlet pipe and a to-be-extracted liquid inlet pipe are both communicated with the extraction cavity; a first driving part of the first stirring assembly is arranged at the bottom of the extraction tank, and the driving end of the first driving part is connected to a first shearing stirring net through a first mounting hole; a second driving part of the second stirring assembly is arranged at the top of the extraction tank, the driving end of the second driving part is connected to a second shearing and stirring net through a second mounting hole, the second shearing and stirring net is located above the first shearing and stirring net, and the rotating speed of the first driving part is larger than that of the second driving part. According to the wet-process phosphoric acid extraction device, by arranging the first shearing and stirring net and the second shearing and stirring net, emulsification and demulsification of a mixed solution of a to-be-extracted solution and an extraction agent are achieved, and therefore the wet-process phosphoric acid extraction efficiency and effect are improved.

The invention provides a large-scale fluid extraction and separation intelligent control method based on a mixing tank structure, and relates to the technical field of intelligent control, and the method comprises the steps: collecting parameter information in a mixing tank through double-cycle sampling, dividing flow field partitions based on three-dimensional numerical characteristics, collecting concentration gradient information of a target object, and building a digital twinborn model; executing a partition self-adaptive control strategy to dynamically adjust stirring parameters, controlling extraction agent supplement, adjusting the opening degree of a partition plate, and monitoring and updating the control strategy in real time. According to the method, precise zone control is realized, the extraction efficiency is improved, the energy consumption is reduced, and the method adapts to complex working condition changes.

This disclosure relates to an annular centrifugal extractor with Solid Separation Part to Separate Solid Particles Present in Solvent Extraction Fluid. In order to remove solid particles from the solution, a solid separation part / rotating bowl is attached to rotating bowl in such a way that solid particles settle inside the solid separation part. This solid separating centrifugal extractor contains two parts: (I) upper part which acts as a liquid-liquid separator to separate aqueous and organic solution used in solvent extraction operation and (II) bottom part which acts as a solid separator to separate solid particle present in solvent extraction liquids. The bottom rotating rotor is coupled with upper rotating rotor by threading arrangement. Both the rotating rotors are confined within a stationary cylinder. Dispersion with solid particles entering inside the rotating bowl is deflected towards the wall of the rotating cylinder by deflecting baffle by centrifugal sedimentation.

The invention belongs to the technical field of pesticide residue detection, and particularly relates to a hydrophobic deep-eutectic solvent and application thereof in pyrethroid pesticide extraction. The hydrophobic deep-eutectic solvent provided by the invention comprises thymol serving as a hydrogen bond acceptor and coumarin or menthol serving as a hydrogen bond donor. Through the hydrophobic interaction between the hydrophobic deep-eutectic solvent and the hydrophobic pyrethroid pesticide, and the strong pi-pi action between the benzene ring structures of coumarin and thymol and the benzene ring of the pyrethroid pesticide, or the adsorption action between the aliphatic ring of menthol and the benzene ring of the pesticide, the pyrethroid pesticide can be prepared. The selective efficient enrichment of the pyrethroid pesticide can be realized through the combined action of the hydrophobic deep-eutectic solvent and the hydrophobic deep-eutectic solvent, the extraction efficiency of the pyrethroid pesticide by the hydrophobic deep-eutectic solvent can be greatly improved, and the detection sensitivity and the detection accuracy of the pyrethroid pesticide can be further improved.

The invention relates to a method for preparing industrial-grade monopotassium phosphate by using a double decomposition extraction method, and belongs to the technical field of fine chemical engineering. The monopotassium phosphate product is prepared from phosphate, sylvite and sulfuric acid through double decomposition and extraction processes. According to the technology, in the reaction process, generated monopotassium phosphate is dissolved in a water phase, generated calcium sulfate dihydrate is precipitate, and the monopotassium phosphate and the calcium sulfate dihydrate can be separated through a simple solid-liquid separation method. A small amount of hydrochloric acid contained in the filtrate can be separated through extraction, so that a byproduct ammonium chloride product is obtained while a high-quality industrial-grade monopotassium phosphate product is obtained. The preparation method disclosed by the invention has the advantages in cost and product quality, the process is easy to realize, and meanwhile, the extraction agent can be recycled.

The invention discloses an egg yolk lecithin separation and extraction device and a technology thereof, and relates to the technical field of separation and extraction, the egg yolk lecithin separation and extraction device comprises: a stirring barrel, the stirring barrel is arranged on the ground; the feeding hole is fixedly formed in the top of the stirring barrel; the solvent tank is fixedly mounted at the top of the stirring barrel, and a chloroform solution is arranged in the solvent tank; the separating funnel is fixedly mounted at the bottom of the stirring barrel, and the separating funnel is used for separating an egg phosphorus solvent from a water phase; the motor is fixedly mounted at the top of the stirring barrel; the stirring rod is fixedly mounted at the output end of the motor, and a reciprocating spiral groove is formed in the surface of the stirring rod; the stirring plate is fixedly mounted at the bottom of the stirring rod; the elastic telescopic rod enables egg yolk and chloroform on the sliding plate to be mixed more sufficiently through up-down movement of the sliding plate.

The present invention addresses the problem of how to effectively and efficiently extract, separate, and recover high-concentration PFAS contained in water regardless of the type of PFAS. An organic fluorine compound is converted to a chemical species having a negative charge on the basis of ionization by acid dissociation of the organic fluorine compound, molecularization of protonation-type hydrophobic cations, or both of these items, the distribution of the organic fluorine compound to an aqueous phase is promoted, and the organic fluorine compound is recovered.

The invention relates to a venturi separator, which is characterized in that the venturi separator comprises a venturi tube and a liquid phase collecting tube surrounding at least one part of structure of the venturi tube, and the venturi tube comprises the following sections which are communicated in sequence: an optional equal-diameter section, a reducing section, a throat part and an expanding section, the venturi separator is provided with a gas phase inlet, a liquid phase inlet, a liquid phase outlet and a gas phase outlet, an opening is formed in the side wall or the tail end of the expanding section of the venturi tube, and the opening leads to the liquid phase collecting tube, so that a liquid phase leaves the venturi tube and enters the liquid phase collecting tube under the action of centrifugal force. The invention also relates to the use of such a Venturi separator in a chemical process.

The invention belongs to the technical field of waste recycling, and particularly relates to a method for recycling nitric acid in acid yellow water based on nitration. The method for recovering nitric acid based on nitration acid yellow water comprises the following steps: stirring nitration acid yellow water and toluene or nitrotoluene and other organic extraction agents in a mixer, adding a certain amount of sulfamic acid, fully extracting, standing for layering, and removing the organic extraction agents through a stripping tower to obtain the nitric acid. The acid yellow water after extraction-steam stripping is sent to a nitric acid absorption-concentration tower to obtain concentrated nitric acid, and the concentrated nitric acid is recycled to a nitration reaction unit as a raw material.

The invention belongs to the technical field of organic matter extraction, and particularly relates to a green directional extraction and purification method for haematococcus astaxanthin, which comprises the following steps: (1) mixing dried haematococcus powder and a composite pretreatment agent according to a mass ratio of 1: (8-15), and stirring to obtain a pretreated algae solution; (2) treating the pretreated algae liquid through ultrahigh-pressure microjet equipment to obtain wall-broken slurry; (3) mixing the wall-broken slurry and a composite extraction agent according to a volume ratio of 1: 3-1: 5, and performing extraction separation to obtain an astaxanthin extraction phase; (4) carrying out selective adsorption on the astaxanthin extraction phase through an adsorption column filled with a molecular imprinting adsorbent; (5) collecting eluent by adopting a gradient elution method; and (6) performing vacuum concentration on the eluent, and performing spray drying to obtain an astaxanthin product. According to the method, the astaxanthin extraction efficiency and the product purity are remarkably improved, meanwhile, the energy consumption is reduced to the maximum extent, toxic solvent residues are avoided, and the stability of the astaxanthin is effectively protected.