Micro-channel extraction reactor with grid plug-in and application of micro-channel extraction reactor

Abstract

The invention relates to the technical field of micro-channel equipment extraction, in particular to a micro-channel extraction reactor with a grid plug-in and application of the micro-channel extraction reactor. The microchannel extraction reactor includes: a microchannel panel; an extraction unit; comprising a containing groove, a linear micro-channel, a front chamber and a rear chamber, the stainless steel filter screen set comprises at least one slightly-curved stainless steel filter screen arranged in the containing groove, the protruding end of the slightly-curved stainless steel filter screen faces the containing groove, and the slightly-curved stainless steel filter screen is arranged between a micro-channel panel and the containing groove; each adjusting unit comprises a sliding supporting piece and an adjusting groove for containing the sliding supporting piece, the sliding supporting pieces stretch out and draw back through the adjusting grooves, and one end of each sliding supporting piece is fixedly connected with the corresponding slightly-bent stainless steel filter screen. The micro-channel extraction reactor can promote sufficient mass transfer of phosphoric acid on an extraction phase interface so as to improve the separation effect of metal element impurities in a phosphoric acid raw material under different flow velocity conditions.

Description

Technical Field

[0001] The present application relates to the field of microchannel equipment extraction technology, and in particular to a microchannel extraction reactor with a grid plug-in and an application thereof. Background Art

[0002] Microchannel extraction technology has the advantages of uniform dispersion of water and oil phases, large specific surface area of ​​droplets, and rapid mass transfer efficiency within and between phases, which makes microchannel extraction technology have high extraction efficiency, so it can be widely used in the fields of extraction and separation of metal ions, organic matter and inorganic matter. At present, common microchannels can be mainly divided into active microchannels and passive microchannels; among them, the structure of active microchannel reactor contains active elements to realize precise control, monitoring and regulation of fluid in microchannel, and often has the characteristics of high flow control accuracy, high reaction efficiency, and adjustable reaction conditions. However, the manufacturing cost of active microchannel reactor is very high, and it is difficult to integrate with other equipment; while the mixing of fluids in passive microchannel reactor does not require external force field, but realizes micromixing through the shape and structure of the channel, or introduces barriers in the microchannel to increase the lateral liquid velocity of the channel, or changes the geometric three-dimensional structure of the microchannel reactor or inserts obstacle plug-ins to increase the contact between the mixed liquids, thereby improving the uniformity of the liquid. Therefore, compared with active microchannel reactors, passive microchannel reactors have the advantages of simple structure, easy preparation, low cost, rapid and uniform mass transfer and easy integration with other equipment. At present, most of the research on the extraction of metal ions by passive microchannel reactors is focused on microextraction techniques that change the shape of the microchannel, such as T-type passive microchannel reactors and Y-type passive microchannel reactors.

[0003] The raw material for producing phosphoric acid is generally phosphate rock, and the impurity content in phosphate rock is high and there are many types, generally containing impurities such as iron, aluminum, magnesium, fluorine, calcium, zinc and organic matter. Therefore, when using this type of phosphate rock as the production raw material of phosphate, the production raw material of food-grade phosphoric acid and the production raw material of electronic-grade phosphoric acid, it is difficult to meet the use requirements and must be purified first. If the above-mentioned T-type passive microchannel reactor and Y-type passive microchannel reactor are directly used for extraction, since the particle size of the impurities containing metal elements is small, it is difficult to separate them through these traditional passive microchannel reactors, resulting in poor separation effect; at this stage, obstacles can be inserted into the passive microchannel reactor or baffles can be established on the microchannel wall to further reduce the distance of the separation channel of the dynamic microchannel reactor, but the operation of obstacles or baffles in the passive microchannel reactor is relatively complicated, and the added obstacles or baffles are relatively fixed and difficult to adapt to different phosphoric acid raw materials, which leads to poor separation effect of some phosphoric acid raw materials with too fast flow rate. Summary of the invention

[0004] The present application provides a microchannel extraction reactor with a grid plug-in and its application to solve the following technical problem: how to improve the separation effect of metal impurities in phosphoric acid raw materials under different flow rate conditions.

[0005] In a first aspect, the present application provides a microchannel extraction reactor having a grid insert, the microchannel extraction reactor comprising: Microchannel panels; The extraction unit comprises a containing tank, a linear microchannel, a front chamber and a rear chamber, wherein the containing tank is arranged in the microchannel extraction reactor; the microchannel panel covers the surface of the containing tank to form an extraction space with the containing tank; the front chamber and the rear chamber are respectively distributed in the containing tank along the length direction of the microchannel panel, and a plurality of the linear microchannels are uniformly distributed between the front chamber and the rear chamber along the width direction of the microchannel panel, and the two ends of the linear microchannel are respectively connected to the front chamber and the rear chamber; A stainless steel filter group, comprising at least one micro-curved stainless steel filter, at least one of the micro-curved stainless steel filter is disposed in the receiving tank, and the protruding end of the micro-curved stainless steel filter is disposed toward the receiving tank, and the micro-curved stainless steel filter is disposed between the microchannel panel and the receiving tank; At least two adjustment units, the two adjustment units are symmetrically arranged at both ends of the microchannel panel along the length direction of the microchannel panel; the adjustment unit includes a sliding support sheet and an adjustment groove for accommodating the sliding support sheet, and the adjustment groove runs through the side wall of the accommodating groove along the width direction; the sliding support sheet is retracted and extended through the adjustment groove, and one end of the sliding support sheet is fixedly connected to the micro-curved stainless steel filter screen, so that the bending degree of the micro-curved stainless steel filter screen can be adjusted through the sliding support sheet.

[0006] Optionally, the length L1 of the slightly curved stainless steel filter screen and the length L2 of the receiving groove satisfy the relationship: L1:L2=(1.01-1.30):1.

[0007] Optionally, the distance d1 between the slightly curved stainless steel filter and the receiving groove and the distance d2 between the sliding support sheet and the receiving groove satisfy the relationship: d1:d2=(0.55-0.95):1; and / or The distance d1 between the slightly curved stainless steel filter screen and the containing tank is 0.55 mm to 0.95 mm.

[0008] Optionally, the pore size of the slightly curved stainless steel filter is 50 mesh to 80 mesh.

[0009] Optionally, the shortest distance d3 between the front chamber and the adjustment groove and the shortest distance d4 between the rear chamber and the adjustment groove satisfy the relationship: d3=d4; The longest telescopic length L3 of the sliding support piece and the shortest distance d3 between the front chamber and the adjustment groove satisfy the relationship: L3=d3.

[0010] Optionally, a mixed liquid phase feed port is provided at the top of the front chamber, and a separated material discharge port is provided at the top of the rear chamber.

[0011] Optionally, an elastic gasket is provided on the surface of the microchannel panel, and the elastic gasket is arranged between the microchannel panel and the receiving groove.

[0012] In a second aspect, the present application provides a microchannel extraction reaction system with a grid insert, the microchannel extraction reaction system comprising: A plurality of microchannel extraction reactors according to the first aspect connected in series, wherein the microchannel extraction reactor is provided with a heat-insulating jacket; A raw material feeding unit, comprising a feeding pump and a three-way valve, wherein the discharge port of the feeding pump is connected to the feed port of the three-way valve, and the discharge port of the three-way valve is connected to the first microchannel extraction reactor; A control unit, comprising a controller, a flow sensor, a stepper motor, a temperature sensor, a thermometer and a constant temperature water bath circulation pump, wherein the flow sensor is arranged between the three-way valve and the first microchannel extraction reactor, and the stepper motor is connected to the sliding support sheet of the microchannel extraction reactor; the temperature sensor is arranged in the insulation jacket of the middle microchannel extraction reactor, and the controller is connected to the flow sensor, the stepper motor, the temperature sensor and the constant temperature water bath circulation pump through electrical signals respectively; the temperature sensor is connected to the thermometer through electrical signals; A liquid separation unit, wherein the feed port of the liquid separation unit is connected to the microchannel extraction reactor at the end.

[0013] In a third aspect, the present application provides a method for purifying phosphoric acid by microchannel extraction, the method being adapted to the microchannel extraction reaction system described in the second aspect; the method comprising: According to the flow rate of phosphoric acid, the curvature of the micro-curved stainless steel filter in the micro-channel extraction reaction system is adjusted to obtain an adjusted micro-channel extraction reaction system; Passing the extractant and the phosphoric acid into the adjusted microchannel extraction reaction system for extraction to obtain an extraction material; Separating the extracted material to obtain purified phosphoric acid; Wherein, the extraction temperature is 35°C to 45°C, and the extraction time is 22.5s to 23.5s.

[0014] Optionally, the curvature of the micro-curved stainless steel filter in the microchannel extraction reaction system is adjusted according to the flow rate of phosphoric acid to obtain an adjusted microchannel extraction reaction system, comprising the steps of: When the flow rate of phosphoric acid is less than 1.0 m / s, the distance d1 between the micro-curved stainless steel filter and the containing tank in the microchannel extraction reaction system is adjusted to 0.85 mm to 0.95 mm; When the flow rate of phosphoric acid is 1.0 m / s to 2.0 m / s, the distance d1 between the micro-curved stainless steel filter and the containing tank in the microchannel extraction reaction system is adjusted to 0.65 mm to 0.80 mm; When the flow rate of phosphoric acid is greater than 2.0 m / s, the distance d1 between the slightly curved stainless steel filter and the containing tank in the microchannel extraction reaction system is adjusted to 0.55 mm to 0.60 mm.

[0015] The above technical solution provided by the embodiment of the present application has the following advantages compared with the prior art: The present application provides a microchannel extraction reactor with a grid plug-in. The microchannel extraction reactor is based on a traditional parallel distributed Y-type multi-channel micro-extractor. A slightly curved stainless steel filter is arranged in a containing tank with a linear microchannel. The relatively large pieces of liquid-phase phosphoric acid are dispersed into phosphoric acid droplets by the slightly curved stainless steel filter, which can increase the complexity of the flow state of the phosphoric acid solution in the liquid-phase fluid, and can also increase the specific surface area and phase interface of the phosphoric acid droplets. The phosphoric acid solution with a more complex flow state and the phosphoric acid droplets with a larger specific surface area and phase interface will improve the mass transfer efficiency of phosphoric acid, thereby promoting phosphoric acid to fully transfer mass at the extraction phase interface, so as to improve the separation effect of metal element impurities in the phosphoric acid raw material; in addition, the curvature of the slightly curved stainless steel filter is adjusted by an adjustment unit including a sliding support sheet and an adjustment tank, and the distance between the slightly curved stainless steel filter and the containing tank can be adjusted according to phosphoric acid with different flow rates, so as to further increase the complexity of the flow state of the phosphoric acid solution in the liquid-phase fluid, thereby promoting phosphoric acid to fully transfer mass at the extraction phase interface, so as to improve the separation effect of metal element impurities in the phosphoric acid raw material under different flow rate conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0018] Figure 1 A schematic diagram of the extraction unit structure of a microchannel extraction reactor with a grid plug-in provided in an embodiment of the present application; Figure 2 A cross-sectional schematic diagram of a microchannel extraction reactor with a grid insert provided in an embodiment of the present application; Figure 3 A schematic diagram of the logical structure of a microchannel extraction reaction system with a grid plug-in provided in an embodiment of the present application; Figure 4 A schematic flow chart of a method for purifying phosphoric acid by microchannel extraction provided in an embodiment of the present application; Figure 5 A detailed schematic diagram of a method for purifying phosphoric acid by microchannel extraction provided in an embodiment of the present application; Figure 6 A result diagram showing the effect of increasing the number of microchannel extraction reactors in series from 1 to 4 on the extraction rate in the microchannel extraction reaction system provided in Example 1 of the present application; Figure 7 A result diagram showing the effect of increasing the number of conventional extraction devices in series from 1 to 4 on the extraction rate provided in Comparative Example 1 of the present application; Among them, 1-microchannel panel, 2-holding tank, 3-linear microchannel, 4-front chamber, 41-mixed liquid phase feed port, 5-back chamber, 51-separated material discharge port, 6-micro-curved stainless steel filter, 7-sliding support plate, 8-adjusting tank, 9-elastic gasket, 10-feeding pump, 11-three-way valve, 12-controller, 13-flow sensor, 14-stepping motor, 15-temperature sensor, 16-thermometer, 17-constant temperature water bath circulation pump, 18-liquid separation unit. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0020] Various embodiments of the present application may be presented in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity and should not be understood as a rigid limitation on the scope of the present application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within the range; for example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6, which applies regardless of the range; in addition, whenever a numerical range is indicated in this document, it is meant to include any cited numbers (fractions or integers) within the indicated range.

[0021] In this document, the terms including "comprising" and the like mean "including but not limited to". Relational terms such as "first" and "second" are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone; wherein A and B can be singular or plural. Unless otherwise specified, various raw materials, reagents, instruments and equipment used in this document can be purchased on the market or prepared by existing methods.

[0022] Figure 1 The schematic diagram of the extraction unit structure of a microchannel extraction reactor with a grid plug-in provided in an embodiment of the present application is exemplarily shown; Figure 2 A cross-sectional schematic diagram of a microchannel extraction reactor with a grid insert provided in an embodiment of the present application is exemplarily shown; like Figure 1 and Figure 2 As shown, the embodiment of the present application provides a microchannel extraction reactor with a grid plug-in, and the microchannel extraction reactor comprises: Microchannel panel 1; The extraction unit comprises a containing tank 2, a linear microchannel 3, a front chamber 4 and a rear chamber 5, wherein the containing tank 2 is arranged in the microchannel extraction reactor; the microchannel panel 1 covers the surface of the containing tank 2 to form an extraction space with the containing tank 2; the front chamber 4 and the rear chamber 5 are respectively distributed in the containing tank 2 along the length direction of the microchannel panel 1, and a plurality of the linear microchannels 3 are uniformly distributed between the front chamber 4 and the rear chamber 5 along the width direction of the microchannel panel 1, and the two ends of the linear microchannel 3 are respectively connected to the front chamber 4 and the rear chamber 5; A stainless steel filter screen group, comprising at least one micro-curved stainless steel filter screen 6, wherein at least one micro-curved stainless steel filter screen 6 is disposed in the receiving tank 2, and a raised end of the micro-curved stainless steel filter screen 6 is disposed toward the receiving tank 2, and the micro-curved stainless steel filter screen 6 is disposed between the microchannel panel 1 and the receiving tank 2; At least two adjustment units, the two adjustment units are symmetrically arranged at both ends of the microchannel panel 1 along the length direction of the microchannel panel 1; the adjustment unit includes a sliding support sheet 7 and an adjustment groove 8 for accommodating the sliding support sheet 7, and the adjustment groove 8 runs through the side wall of the accommodating groove 2 along the width direction; the sliding support sheet 7 is retracted and extended through the adjustment groove 8, and one end of the sliding support sheet 7 is fixedly connected to the micro-curved stainless steel filter screen 6, so as to adjust the bending degree of the micro-curved stainless steel filter screen 6 through the sliding support sheet 7.

[0023] It should be noted that the fixed connection between the slightly curved stainless steel filter 6 and the sliding support sheet 7 can be achieved by bending both ends of the slightly curved stainless steel filter 6 into fixed grooves, and providing matching protrusions at both ends of the sliding support sheet 7.

[0024] It should be noted that the sliding support sheet 7 and the adjustment groove 8 may be sealed and waterproofed to avoid water leakage during the adjustment process.

[0025] It should be noted that the microchannel extraction reactor can be modified based on a parallel distributed Y-type multi-channel microextractor, and the single microextractor used in the parallel distributed Y-type multi-channel microextractor can be an extraction device as disclosed in CN202310860292.5; in the parallel distributed Y-type multi-channel microextractor, a plurality of microchannels will reduce the cross-sectional size of the mixed water-oil two-phase to the size of the microchannel interface, thereby promoting the water-oil two-phase droplets to have a larger specific surface area and phase interface, so that the larger water-oil two-phase contact area is carried out. The Y-shaped structure forces the water-oil two-phase liquids to meet each other at a certain angle, causing the continuous phase liquid velocity to be mostly deflected at the intersection, while the remaining part of the liquid still maintains the original velocity direction, while the droplets of the other part of the liquid undergo a certain degree of extrusion deformation or even rupture, resulting in further dispersion of the liquid droplets, thereby causing the water-oil two-phase droplets to collide more violently and increase the contact area of ​​the water-oil two-phase liquids; in addition, the linear part at the rear end of the Y-shaped structure can provide a stable environment for the contact between the water and oil phases, allowing them to fully transfer mass at the phase interface.

[0026] It should be noted that the material of the microchannel panel 1 can be an organic glass shell, which has the characteristics of transparency and high hydrophilicity, and can be used to observe the flow state of the liquid phase in the microchannel extraction reactor.

[0027] In some optional embodiments, the length L1 of the slightly curved stainless steel filter screen 6 and the length L2 of the receiving tank 2 satisfy the relationship: L1:L2=(1.01-1.30):1; In these embodiments, the length L1 of the slightly curved stainless steel filter 6 and the length L2 of the containing tank 2 can satisfy the relationship: L1:L2=(1.01-1.30):1, which can cause the slightly curved stainless steel filter 6 to have a sufficient degree of curvature. The slightly curved stainless steel filter 6 with a sufficient degree of curvature can disperse larger pieces of liquid phosphoric acid into phosphoric acid droplets, so as to increase the complexity of the flow state of the phosphoric acid solution in the liquid phase fluid and the specific surface area and phase interface of the phosphoric acid droplets, thereby improving the separation effect of metal element impurities in the phosphoric acid raw material under different flow rate conditions.

[0028] The length L1 of the slightly curved stainless steel filter screen 6 and the length L2 of the receiving tank 2 may satisfy the relationship: L1:L2=1.01:1, 1.02:1, 1.03:1, 1.04:1, 1.05:1, 1.10:1, 1.15:1, 1.20:1, 1.25:1 or 1.30:1.

[0029] In some optional embodiments, the distance d1 between the slightly curved stainless steel filter screen 6 and the receiving groove 2 and the distance d2 between the sliding support sheet 7 and the receiving groove 2 satisfy the relationship: d1:d2=(0.55-0.95):1; and / or The distance d1 between the slightly curved stainless steel filter screen 6 and the receiving tank 2 is 0.55 mm to 0.95 mm; In these embodiments, the distance d1 between the micro-curved stainless steel filter 6 and the receiving tank 2 and the distance d2 between the sliding support sheet 7 and the receiving tank 2 can satisfy the relationship: d1:d2=(0.55~0.95):1, and the distance d1 between the micro-curved stainless steel filter 6 and the receiving tank 2 can be 0.55mm~0.95mm, so that the distance between the micro-curved stainless steel filter 6 and the receiving tank 2 is within an adjustable range, and the distance between the micro-curved stainless steel filter 6 and the receiving tank 2 can be adjusted according to the different flow rates of phosphoric acid to further increase the complexity of the flow state of the phosphoric acid solution in the liquid phase fluid, thereby promoting sufficient mass transfer of phosphoric acid at the extraction phase interface to improve the separation effect of metal element impurities in the phosphoric acid raw material under different flow rate conditions.

[0030] The distance d1 between the slightly curved stainless steel filter screen 6 and the receiving groove 2 and the distance d2 between the sliding support sheet 7 and the receiving groove 2 can satisfy the relationship: d1:d2=0.55:1, 0.60:1, 0.65:1, 0.70:1, 0.75:1, 0.80:1, 0.85:1, 0.90:1 or 0.95:1.

[0031] The distance d1 between the slightly curved stainless steel filter screen 6 and the containing tank 2 may be 0.55 mm, 0.60 mm, 0.65 mm, 0.70 mm, 0.75 mm, 0.80 mm, 0.85 mm, 0.90 mm or 0.95 mm.

[0032] It should be noted that the phosphoric acid undergoes sufficient mass transfer at the extraction phase interface, which means that the metal impurities in the phosphoric acid are transferred from the aqueous phase of the phosphoric acid to the extractant to obtain a pure phosphoric acid product.

[0033] In some optional embodiments, the aperture of the slightly curved stainless steel filter 6 is 50-80 mesh; In these embodiments, the pore size of the micro-curved stainless steel filter 6 can be 50 mesh to 80 mesh, so that the micro-curved stainless steel filter 6 has a good pore size to further increase the complexity of the flow state of the phosphoric acid solution in the liquid phase fluid, thereby promoting sufficient mass transfer of phosphoric acid at the extraction phase interface to improve the separation effect of metal element impurities in the phosphoric acid raw material under different flow rate conditions.

[0034] The aperture of the slightly curved stainless steel filter screen 6 can be 50 mesh, 55 mesh, 60 mesh, 65 mesh, 70 mesh, 75 mesh or 80 mesh.

[0035] In some optional embodiments, the shortest distance d3 between the front chamber 4 and the adjustment groove 8 and the shortest distance d4 between the rear chamber 5 and the adjustment groove 8 satisfy the relationship: d3=d4; The longest telescopic length L3 of the sliding support sheet 7 and the shortest distance d3 between the front chamber 4 and the adjustment groove 8 satisfy the relationship: L3=d3; In these embodiments, the shortest distance d3 between the front chamber 4 and the adjustment groove 8 and the shortest distance d4 between the rear chamber 5 and the adjustment groove 8 can satisfy the relationship: d3=d4, and the telescopic length L3 of the sliding support plate 7 and the shortest distance d3 between the front chamber 4 and the adjustment groove 8 can satisfy the relationship: L3=d3, which can avoid the sliding support plate 7 from blocking the front chamber 4 and the rear chamber 5 during the telescopic process, thereby promoting sufficient mass transfer of phosphoric acid at the extraction phase interface, so as to improve the separation effect of metal element impurities in the phosphoric acid raw material under different flow rate conditions.

[0036] In some optional embodiments, a mixed liquid phase feed port 41 is provided at the top of the front chamber 4, and a separated material discharge port 51 is provided at the top of the rear chamber 5; In these embodiments, a mixed liquid phase feed port 41 is provided at the top of the front chamber 4, and a separation material discharge port 51 is provided at the top of the rear chamber 5. According to the distribution positions of the front chamber 4 and the rear chamber 5, sufficient mass transfer of phosphoric acid at the extraction phase interface can be promoted to improve the separation effect of metal element impurities in the phosphoric acid raw material under different flow rate conditions.

[0037] In some optional embodiments, an elastic gasket 9 is provided on the surface of the microchannel panel 1, and the elastic gasket 9 is provided between the microchannel panel 1 and the receiving groove 2; In these embodiments, an elastic gasket 9 may be provided on the surface of the microchannel panel 1, and the elastic gasket 9 is provided between the microchannel panel 1 and the receiving tank 2. The elastic gasket 9 is used to seal the gap between the microchannel panel 1 and the receiving tank 2 to avoid leakage of the phosphoric acid raw material liquid and other unnecessary interference factors, thereby ensuring the stable operation of the microchannel extraction reactor.

[0038] Figure 3 The logical structure diagram of a microchannel extraction reaction system with a grid plug-in provided in an embodiment of the present application is exemplarily shown; Based on a general inventive concept, such as Figure 3 As shown, the embodiment of the present application provides a microchannel extraction reaction system with a grid plug-in, and the microchannel extraction reaction system includes: A plurality of microchannel extraction reactors connected in series, wherein the microchannel extraction reactor is provided with a heat-insulating jacket; A raw material feeding unit, comprising a feeding pump 10 and a three-way valve 11, wherein the discharge port of the feeding pump 10 is connected to the feed port of the three-way valve 11, and the discharge port of the three-way valve 11 is connected to the first microchannel extraction reactor; The control unit includes a controller 12, a flow sensor 13, a stepper motor 14, a temperature sensor 15, a thermometer 16 and a constant temperature water bath circulation pump 17. The flow sensor 13 is arranged between the three-way valve 11 and the first microchannel extraction reactor, and the stepper motor 14 is connected to the sliding support sheet 7 of the microchannel extraction reactor; the temperature sensor 15 is arranged in the insulation jacket of the middle microchannel extraction reactor, and the controller 12 is connected to the flow sensor 13, the stepper motor 14, the temperature sensor 15 and the constant temperature water bath circulation pump 17 through electrical signals respectively; the temperature sensor 15 is connected to the thermometer 16 through electrical signals; The liquid separation unit 18 has a feed port connected to the microchannel extraction reactor at the end.

[0039] The microchannel extraction reaction system is realized based on the above-mentioned microchannel extraction reactor. The specific structure of the microchannel extraction reactor can refer to the above-mentioned embodiment. Since the microchannel extraction reaction system adopts part or all of the technical solutions of the above-mentioned embodiment, it at least has all the beneficial effects brought by the technical solutions of the above-mentioned embodiment, which will not be repeated here one by one.

[0040] It should be noted that the controller 12 may be a S7-200 SMART PLC controller 12 ; the flow sensor 13 may be a Helen SEN-HZ06W flow sensor 13 ; and the temperature sensor 15 may be a WRNT-10 stainless steel K-type temperature sensor 15 .

[0041] Figure 4 A schematic flow chart of a method for purifying phosphoric acid by microchannel extraction provided in an embodiment of the present application is shown by way of example; Based on a general inventive concept, such as Figure 4 As shown, the embodiment of the present application provides a method for purifying phosphoric acid by microchannel extraction, and the method is adapted to the microchannel extraction reaction system; the method comprises: S1. According to the flow rate of phosphoric acid, the curvature of the micro-curved stainless steel filter 6 in the microchannel extraction reaction system is adjusted to obtain an adjusted microchannel extraction reaction system; S2. The extractant and the phosphoric acid are introduced into the adjusted microchannel extraction reaction system for extraction to obtain an extraction material; S3. separating the extracted material to obtain purified phosphoric acid; Wherein, the extraction temperature is 35°C to 45°C, and the extraction time is 22.5s to 23.5s.

[0042] The method is implemented based on the above-mentioned microchannel extraction reaction system. The specific structure of the microchannel extraction reaction system can refer to the above-mentioned embodiment. Since the method adopts part or all of the technical solutions of the above-mentioned embodiment, it at least has all the beneficial effects brought by the technical solutions of the above-mentioned embodiment, which will not be repeated here one by one.

[0043] It should be noted that the extraction temperature can be 35° C. to 45° C., and the extraction time can be 22.5 s to 23.5 s. The microchannel extraction reaction system can enable the extractant to effectively extract impurities in the phosphoric acid raw material.

[0044] The temperature of the extraction can be 35°C, 36°C, 37°C, 38°C, 39°C, 40°C, 41°C, 42°C, 43°C, 44°C or 45°C.

[0045] The extraction time can be 22.5s, 22.6s, 22.7s, 22.8s, 22.9s, 23.0s, 23.1s, 23.2s, 23.3s, 23.4s or 23.5s.

[0046] It should be noted that the introduction flow rate of the extractant and the phosphoric acid can be 1:1.

[0047] It should be noted that the extractant can be a mixed solution of extractant P204 and kerosene, and the mass concentration of the extractant P204 can be 50%.

[0048] Figure 5 A detailed schematic diagram of a method for purifying phosphoric acid by microchannel extraction provided in an embodiment of the present application is shown by way of example; In some optional embodiments, the curvature of the micro-curved stainless steel filter 6 in the micro-channel extraction reaction system is adjusted according to the flow rate of phosphoric acid to obtain an adjusted micro-channel extraction reaction system, comprising the steps of: S101. When the flow rate of phosphoric acid is less than 1.0 m / s, the distance d1 between the micro-curved stainless steel filter 6 and the receiving tank 2 in the microchannel extraction reaction system is adjusted to 0.85 mm to 0.95 mm; S102. When the flow rate of phosphoric acid is 1.0 m / s to 2.0 m / s, the distance d1 between the micro-curved stainless steel filter 6 and the receiving tank 2 in the microchannel extraction reaction system is adjusted to 0.65 mm to 0.80 mm; S103. When the flow rate of phosphoric acid is >2.0 m / s, the distance d1 between the micro-curved stainless steel filter 6 and the receiving tank 2 in the microchannel extraction reaction system is adjusted to 0.55 mm to 0.60 mm; In these embodiments, the distance d1 between the micro-curved stainless steel filter 6 and the containing tank 2 in the microchannel extraction reaction system is adjusted respectively with the flow rate of 1.0 m / s and 2.0 m / s as the limit, and the gap width between the micro-curved stainless steel filter 6 and the containing tank 2 can be adjusted according to the actual flow rate of the phosphoric acid raw material to further increase the complexity of the flow state of the phosphoric acid solution in the liquid phase fluid, thereby promoting sufficient mass transfer of phosphoric acid at the extraction phase interface to improve the separation effect of metal element impurities in the phosphoric acid raw material under different flow rate conditions.

[0049] It should be noted that, when the flow rate of phosphoric acid is less than 1.0 m / s, the distance d1 between the micro-curved stainless steel filter screen 6 and the receiving tank 2 in the microchannel extraction reaction system can be adjusted to 0.85 mm, 0.86 mm, 0.87 mm, 0.88 mm, 0.89 mm, 0.90 mm, 0.91 mm, 0.92 mm, 0.93 mm, 0.94 mm or 0.95 mm; when the flow rate of phosphoric acid is 1.0 m / s to 2.0 m / s, the distance d1 between the micro-curved stainless steel filter screen 6 and the receiving tank 2 in the microchannel extraction reaction system can be adjusted to 0.65 mm , 0.66mm, 0.67mm, 0.68mm, 0.69mm, 0.70mm, 0.71mm, 0.72mm, 0.73mm, 0.74mm, 0.75mm, 0.76mm, 0.77mm, 0.78mm, 0.79mm or 0.80mm; when the flow rate of phosphoric acid is greater than 2.0m / s, the distance d1 between the micro-curved stainless steel filter screen 6 and the containing tank 2 in the microchannel extraction reaction system can be adjusted to 0.55mm, 0.56mm, 0.57mm, 0.58mm, 0.59mm or 0.60mm.

[0050] The present application is further described below in conjunction with specific examples. The experimental methods in the following examples where specific conditions are not specified are usually measured in accordance with national standards / industry standards; if there are no corresponding national standards / industry standards, they are measured in accordance with common international standards, conventional conditions or conditions recommended by the manufacturer. Example 1

[0051] like Figure 1 and Figure 2 As shown, a microchannel extraction reactor with a grid insert comprises: Microchannel panel 1; The extraction unit comprises a containing tank 2, a linear microchannel 3, a front chamber 4 and a rear chamber 5, wherein the containing tank 2 is arranged in a microchannel extraction reactor; a microchannel panel 1 covers the surface of the containing tank 2 to form an extraction space with the containing tank 2; the front chamber 4 and the rear chamber 5 are respectively distributed in the containing tank 2 along the length direction of the microchannel panel 1, and a plurality of linear microchannels 3 are evenly distributed between the front chamber 4 and the rear chamber 5 along the width direction of the microchannel panel 1, and the two ends of the linear microchannel 3 are respectively connected to the front chamber 4 and the rear chamber 5; The stainless steel filter screen group includes a micro-curved stainless steel filter screen 6, at least one micro-curved stainless steel filter screen 6 is arranged in the receiving tank 2, and the protruding end of the micro-curved stainless steel filter screen 6 is arranged toward the receiving tank 2, and the micro-curved stainless steel filter screen 6 is arranged between the microchannel panel 1 and the receiving tank 2; Two adjustment units are symmetrically arranged at both ends of the microchannel panel 1 along the length direction of the microchannel panel 1; the adjustment unit includes a sliding support sheet 7 and an adjustment groove 8 for accommodating the sliding support sheet 7, and the adjustment groove 8 runs through the side wall of the accommodating groove 2 along the width direction; the sliding support sheet 7 is retracted and extended through the adjustment groove 8, and one end of the sliding support sheet 7 is fixedly connected to the micro-curved stainless steel filter screen 6, so that the bending degree of the micro-curved stainless steel filter screen 6 can be adjusted through the sliding support sheet 7.

[0052] The length L1 of the slightly curved stainless steel filter screen 6 and the length L2 of the receiving tank 2 satisfy the relationship: L1:L2=1.20:1.

[0053] The distance d1 between the slightly curved stainless steel filter screen 6 and the receiving groove 2 and the distance d2 between the sliding support sheet 7 and the receiving groove 2 satisfy the relationship: d1:d2=0.70:1.

[0054] The distance d1 between the slightly curved stainless steel filter screen 6 and the containing tank 2 is 0.70 mm.

[0055] The aperture of the slightly curved stainless steel filter screen 6 is 50 meshes.

[0056] The shortest distance d3 between the front chamber 4 and the adjustment groove 8 and the shortest distance d4 between the rear chamber 5 and the adjustment groove 8 satisfy the relationship: d3=d4; The longest telescopic length L3 of the sliding support piece 7 and the shortest distance d3 between the front chamber 4 and the adjustment groove 8 satisfy the relationship: L3=d3.

[0057] A mixed liquid phase feed inlet 41 is disposed at the top of the front chamber 4 , and a separated material discharge outlet 51 is disposed at the top of the rear chamber 5 .

[0058] An elastic gasket 9 is provided on the surface of the microchannel panel 1 , and the elastic gasket 9 is arranged between the microchannel panel 1 and the containing groove 2 .

[0059] like Figure 3 As shown, a microchannel extraction reaction system with a grid insert comprises: Three microchannel extraction reactors connected in series, the microchannel extraction reactors being provided with a heat-insulating jacket; The raw material feeding unit comprises a feeding pump 10 and a three-way valve 11, wherein the discharge port of the feeding pump 10 is connected to the feed port of the three-way valve 11, and the discharge port of the three-way valve 11 is connected to the first microchannel extraction reactor; The control unit includes a controller 12, a flow sensor 13, a stepper motor 14, a temperature sensor 15, a thermometer 16 and a constant temperature water bath circulation pump 17. The flow sensor 13 is arranged between the three-way valve 11 and the first microchannel extraction reactor, and the stepper motor 14 is connected to the sliding support sheet 7 of the microchannel extraction reactor; the temperature sensor 15 is arranged in the insulation jacket of the middle microchannel extraction reactor, and the controller 12 is connected to the flow sensor 13, the stepper motor 14, the temperature sensor 15 and the constant temperature water bath circulation pump 17 through electrical signals respectively; the temperature sensor 15 is connected to the thermometer 16 through electrical signals; The liquid separation unit 18 has a feed port connected to the final microchannel extraction reactor.

[0060] The extractant P204 was added to kerosene to prepare an organic phase with a mass fraction of 50%; then a certain amount of phosphoric acid solution and solid zinc sulfate heptahydrate were added to deionized water to prepare a solution with a zinc ion content of 50 ppm and a phosphoric acid content of 25% as aqueous phosphoric acid.

[0061] like Figure 4 As shown, a method for purifying phosphoric acid by microchannel extraction comprises: S102. When the flow rate of phosphoric acid is 1.5 m / s, the distance d1 between the micro-curved stainless steel filter 6 and the receiving tank 2 in the microchannel extraction reaction system is adjusted to 0.70 mm to obtain an adjusted microchannel extraction reaction system; S2. The extractant and phosphoric acid are introduced into the adjusted microchannel extraction reaction system for extraction to obtain an extracted material; S3. The extracted material is separated to obtain purified phosphoric acid; The extraction temperature was 40°C and the extraction time was 23.11s.

[0062] Example 2 Based on the contents disclosed in Example 1, the following modifications are further made: The length L1 of the slightly curved stainless steel filter screen 6 and the length L2 of the receiving tank 2 satisfy the relationship: L1:L2=1.18:1.

[0063] The distance d1 between the slightly curved stainless steel filter screen 6 and the receiving groove 2 and the distance d2 between the sliding support sheet 7 and the receiving groove 8 satisfy the relationship: d1:d2=0.65:1.

[0064] The distance d1 between the slightly curved stainless steel filter screen 6 and the containing tank 2 is 0.65 mm.

[0065] The pore size of the micro-curved stainless steel filter is 70 mesh.

[0066] Example 3 Based on the contents disclosed in Example 1, the following modifications are further made: The length L1 of the slightly curved stainless steel filter screen 6 and the length L2 of the receiving tank 2 satisfy the relationship: L1:L2=1.23:1.

[0067] The distance d1 between the slightly curved stainless steel filter screen 6 and the receiving groove 2 and the distance d2 between the sliding support sheet 7 and the receiving container 28 satisfy the relationship: d1:d2=0.80:1.

[0068] The distance d1 between the slightly curved stainless steel filter screen 6 and the containing tank 2 is 0.80 mm.

[0069] The aperture of the slightly curved stainless steel filter screen 6 is 80 meshes.

[0070] Example 4 Based on the contents disclosed in Example 1, the following modifications are further made: S101. When the flow rate of phosphoric acid is 0.5 m / s, the distance d1 between the slightly curved stainless steel filter 6 and the containing tank 2 in the microchannel extraction reaction system is adjusted to 0.90 mm to obtain an adjusted microchannel extraction reaction system.

[0071] The length L1 of the slightly curved stainless steel filter screen 6 and the length L2 of the receiving tank 2 satisfy the relationship: L1:L2=1.02:1.

[0072] The distance d1 between the slightly curved stainless steel filter screen 6 and the receiving groove 2 and the distance d2 between the sliding support sheet 7 and the receiving groove 2 satisfy the relationship: d1:d2=0.90:1.

[0073] Example 5 Based on the contents disclosed in Example 1, the following modifications are further made: S103. When the flow rate of phosphoric acid is 3.0 m / s, the distance d1 between the slightly curved stainless steel filter 6 and the containing tank 2 in the microchannel extraction reaction system is adjusted to 0.55 mm to obtain the adjusted microchannel extraction reaction system.

[0074] The length L1 of the slightly curved stainless steel filter screen 6 and the length L2 of the receiving tank 2 satisfy the relationship: L1:L2=1.29:1.

[0075] The distance d1 between the slightly curved stainless steel filter screen 6 and the receiving groove 2 and the distance d2 between the sliding support sheet 7 and the receiving groove 2 satisfy the relationship: d1:d2=0.55:1.

[0076] Example 6 Based on the contents disclosed in Example 1, the following modifications are further made: The extraction temperature was 35°C and the extraction time was 23.5s.

[0077] Example 7 Based on the contents disclosed in Example 1, the following modifications are further made: The extraction temperature was 45°C and the extraction time was 22.5s.

[0078] Comparative Example 1 Based on the contents disclosed in Example 1, the following modifications are further made: Without using microchannel extraction reaction system, the specific process is: The aqueous phase and the organic phase were placed in a conical flask and placed in a constant temperature water bath oscillator at 40°C for 24 seconds, and then a four-stage extraction experiment was performed using a separatory funnel.

[0079] Comparative Example 2 Based on the contents disclosed in Example 1, the following modifications are further made: The length L1 of the slightly curved stainless steel filter screen 6 and the length L2 of the receiving tank 2 satisfy the relationship: L1:L2=1.29:1.

[0080] The distance d1 between the slightly curved stainless steel filter screen 6 and the receiving groove 2 and the distance d2 between the sliding support sheet 7 and the receiving groove 2 satisfy the relationship: d1:d2=0.55:1.

[0081] The distance d1 between the slightly curved stainless steel filter screen 6 and the containing tank 2 is 0.55 mm.

[0082] Comparative Example 3 Based on the contents disclosed in Example 1, the following modifications are further made: The length L1 of the slightly curved stainless steel filter screen 6 and the length L2 of the receiving tank 2 satisfy the relationship: L1:L2=1.02:1.

[0083] The distance d1 between the slightly curved stainless steel filter screen 6 and the receiving groove 2 and the distance d2 between the sliding support sheet 7 and the receiving groove 2 satisfy the relationship: d1:d2=0.90:1.

[0084] The distance d1 between the slightly curved stainless steel filter screen 6 and the containing tank 2 is 0.90 mm.

[0085] Related experiments and effect data: Based on the microchannel extraction reactor disclosed in Example 1, the number of microchannel extraction reactors in series in the microchannel extraction reaction system is gradually increased from 1 to 4. In addition, based on the traditional extraction disclosed in Comparative Example 1, the number of separating funnels is gradually increased from 1 to 4. The final result is as follows: Figure 6 and Figure 7 shown.

[0086] The purified phosphoric acid obtained in each embodiment and comparative example and the separated aqueous phase were collected respectively, and the zinc ion concentration of the separated aqueous phase was measured using an atomic absorption spectrometer. The extraction rate of the entire method or system was determined according to the change in the zinc ion concentration, wherein the extraction rate is the ratio of the zinc ion concentration in the separated aqueous phase to the zinc ion concentration in the phosphoric acid raw material solution; the results are shown in Table 1.

[0087] Table 1 Extraction rates of purified phosphoric acid and aqueous phase obtained in various examples and comparative examples

[0088] From Table 1 and Figure 6 and Figure 7 It can be seen that the embodiment of the present application provides a microchannel extraction reactor with a grid plug-in. The microchannel extraction reactor is based on a traditional parallel distributed Y-type multi-channel micro-extractor, and a slightly curved stainless steel filter screen 6 is arranged in a receiving tank with a linear microchannel, and an adjustment unit including a sliding support plate 7 and an adjustment tank 8 adjusts the curvature of the micro-curved stainless steel filter screen 6, which can promote sufficient mass transfer of phosphoric acid at the extraction phase interface to improve the separation effect of metal element impurities in the phosphoric acid raw material under different flow rate conditions.

[0089] In addition, an embodiment of the present application provides a microchannel extraction reactor with a grid plug-in. The microchannel extraction reactor has a simple structure and each component can be disassembled and assembled, thereby facilitating operations such as replacement, maintenance, and cleaning of each component.

[0090] In addition, an embodiment of the present application provides a microchannel extraction reaction system with a grid plug-in. Under the same operating temperature, the microchannel extraction reaction system can achieve the same extraction efficiency at a lower oil-water ratio (volume ratio of 1:1) and a shorter extraction time than the extraction system used in the traditional extraction method, which can significantly reduce the extraction time and save the amount of extraction agent, thereby significantly improving production efficiency and reducing production costs.

[0091] In addition, an embodiment of the present application provides a microchannel extraction reaction system with a grid plug-in. The microchannel extraction reaction system can reduce the concentration of impure metal zinc ions in strong acid from 50 ppm to about 25 ppm in a strong acid environment, has a good extraction enhancement effect, and has important application significance in the deep purification of chemical impurities in strong acid.

[0092] In addition, an embodiment of the present application provides a microchannel extraction reaction system with a grid plug-in. The structural components of the microchannel extraction reaction system make its manufacturing cost lower and easier to integrate with other equipment.

[0093] The above is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. It will be apparent to those skilled in the art that various modifications to these embodiments are possible, and the general principles defined in the present application can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown in the present application, but will conform to the widest scope consistent with the principles and novel features applied for by the present application.

Claims

1. A microchannel extraction reactor with a grid insert, the microchannel extraction reactor comprising: Microchannel panel (1); Extraction unit; The invention comprises a containing tank (2), a linear microchannel (3), a front chamber (4) and a rear chamber (5), wherein the containing tank (2) is arranged in the microchannel extraction reactor; the microchannel panel (1) covers the surface of the containing tank (2) to form an extraction space with the containing tank (2); the front chamber (4) and the rear chamber (5) are respectively distributed in the containing tank (2) along the length direction of the microchannel panel (1) at intervals, a plurality of the linear microchannels (3) are evenly distributed between the front chamber (4) and the rear chamber (5) along the width direction of the microchannel panel (1), and the two ends of the linear microchannel (3) are respectively connected to the front chamber (4) and the rear chamber (5); A stainless steel filter screen group, comprising at least one micro-curved stainless steel filter screen (6), wherein at least one of the micro-curved stainless steel filter screens (6) is arranged in the receiving groove (2), and a protruding end of the micro-curved stainless steel filter screen (6) is arranged toward the receiving groove (2), and the micro-curved stainless steel filter screen (6) is arranged between the micro-channel panel (1) and the receiving groove (2); At least two adjustment units are provided, the two adjustment units being symmetrically arranged at two ends of the microchannel panel (1) along the length direction of the microchannel panel (1); the adjustment units comprising a sliding support sheet (7) and an adjustment groove (8) for accommodating the sliding support sheet (7), the adjustment groove (8) penetrating the side wall of the accommodating groove (2) along the width direction; the sliding support sheet (7) is extended and retracted through the adjustment groove (8), and one end of the sliding support sheet (7) is fixedly connected to the micro-curved stainless steel filter (6), so that the degree of bending of the micro-curved stainless steel filter (6) is adjusted through the sliding support sheet (7).

2. According to the microchannel extraction reactor of claim 1, the length L1 of the micro-curved stainless steel filter (6) and the length L2 of the containing tank (2) satisfy the relationship: L1:L2=(1.01-1.30):

1.

3. The microchannel extraction reactor according to claim 1 or 2, wherein the distance d1 between the micro-curved stainless steel filter (6) and the receiving tank (2) and the distance d2 between the sliding support sheet (7) and the receiving tank (2) satisfy the relationship: d1:d2=(0.55-0.95):1; and / or The distance d1 between the slightly curved stainless steel filter screen (6) and the containing groove (2) is 0.55 mm to 0.95 mm.

4. The microchannel extraction reactor according to claim 1, wherein the pore size of the micro-curved stainless steel filter (6) is 50-80 meshes.

5. The microchannel extraction reactor according to claim 1, wherein the shortest distance d3 between the front chamber (4) and the adjustment tank (8) and the shortest distance d4 between the rear chamber (5) and the adjustment tank (8) satisfy the relationship: d3=d4; The longest telescopic length L3 of the sliding support plate (7) and the shortest distance d3 between the front chamber (4) and the adjustment groove (8) satisfy the relationship: L3=d3.

6. The microchannel extraction reactor according to claim 1, wherein a mixed liquid phase feed port (41) is disposed at the top of the front chamber (4), and a separated material discharge port (51) is disposed at the top of the rear chamber (5).

7. The microchannel extraction reactor according to claim 1, wherein an elastic gasket (9) is provided on the surface of the microchannel panel (1), and the elastic gasket (9) is provided between the microchannel panel (1) and the containing tank (2).

8. A microchannel extraction reaction system with a grid insert, the microchannel extraction reaction system comprising: A plurality of microchannel extraction reactors according to any one of claims 1 to 7 connected in series, wherein the microchannel extraction reactor is provided with a heat-insulating jacket; A raw material feeding unit comprises a feeding pump (10) and a three-way valve (11), wherein the discharge port of the feeding pump (10) is connected to the feed port of the three-way valve (11), and the discharge port of the three-way valve (11) is connected to the first microchannel extraction reactor; A control unit, comprising a controller (12), a flow sensor (13), a stepper motor (14), a temperature sensor (15), a thermometer (16) and a constant temperature water bath circulation pump (17), wherein the flow sensor (13) is arranged between the three-way valve (11) and the first microchannel extraction reactor, and the stepper motor (14) is connected to the sliding support sheet (7) of the microchannel extraction reactor; the temperature sensor (15) is arranged in the insulation jacket of the middle microchannel extraction reactor, and the controller (12) is connected to the flow sensor (13), the stepper motor (14), the temperature sensor (15) and the constant temperature water bath circulation pump (17) respectively through electrical signals; the temperature sensor (15) is connected to the thermometer (16) through electrical signals; A liquid separation unit (18), wherein the feed port of the liquid separation unit (18) is connected to the microchannel extraction reactor at the end.

9. A method for purifying phosphoric acid by microchannel extraction, the method being adapted to the microchannel extraction reaction system of claim 8; the method comprising: According to the flow rate of phosphoric acid, the curvature of the micro-curved stainless steel filter (6) in the micro-channel extraction reaction system is adjusted to obtain an adjusted micro-channel extraction reaction system; Passing the extractant and the phosphoric acid into the adjusted microchannel extraction reaction system for extraction to obtain an extraction material; Separating the extracted material to obtain purified phosphoric acid; Wherein, the extraction temperature is 35°C to 45°C, and the extraction time is 22.5s to 23.5s.

10. The method according to claim 9, wherein the curvature of the micro-curved stainless steel filter (6) in the micro-channel extraction reaction system is adjusted according to the flow rate of phosphoric acid to obtain the adjusted micro-channel extraction reaction system, comprising the steps of: When the flow rate of phosphoric acid is less than 1.0 m / s, the distance d1 between the micro-curved stainless steel filter screen (6) and the containing tank (2) in the micro-channel extraction reaction system is adjusted to 0.85 mm to 0.95 mm; When the flow rate of phosphoric acid is 1.0 m / s to 2.0 m / s, the distance d1 between the micro-curved stainless steel filter screen (6) and the containing tank (2) in the micro-channel extraction reaction system is adjusted to 0.65 mm to 0.80 mm; When the flow rate of phosphoric acid is greater than 2.0 m / s, the distance d1 between the micro-curved stainless steel filter screen (6) and the containing tank (2) in the micro-channel extraction reaction system is adjusted to be 0.55 mm to 0.60 mm.

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