Rotary microreactor and liquid-liquid extraction method

Abstract

The invention belongs to the field of chemical separation methods and equipment, and provides a rotary microreactor and a liquid-liquid extraction method. The rotary micro-reactor comprises a driving device, a rotary shaft, a centrifugal phase separation structure, a plurality of rotary discs and a fixed circular ring, the rotary discs and the fixed circular ring are alternately arranged, the rotary shaft is composed of a rotary disc mounting section and a material conveying section, the rotary discs are horizontally arranged on the rotary disc mounting section, and the fixed circular ring is horizontally arranged on the inner side wall of the lower shell; the centrifugal phase separation structure is located above the lower shell and comprises a separation barrel and an upper shell, and a separation barrel feeding opening is formed in the bottom of the separation barrel; the lower end of the rotating shaft is connected with the driving device, and the upper end of the rotating shaft is communicated with the separating cylinder feeding port; the rotating disc mounting section and the liquid inlet are located in the lower shell; the axis of the lower shell is perpendicular to the horizontal plane, and the rotary disc, the fixed circular ring, the rotary shaft, the separation barrel and the lower shell are coaxially arranged. According to the invention, continuous high-efficiency mass transfer and phase separation can be realized, and the industrial amplification difficulty of the microreactor is reduced.

Description

Technical Field

[0001] The invention belongs to the field of chemical separation methods and equipment, and relates to a rotary microreactor and a liquid-liquid extraction method. Background Art

[0002] Liquid-liquid extraction is a key separation technology in the chemical industry, achieving efficient separation of target components through selective mass transfer between the liquid-liquid phases. As a high-efficiency liquid-liquid extraction and chemical reaction process intensification equipment, microreactors can significantly improve the contact area and mass transfer efficiency of the two phases due to their microchannel structure. However, conventional microreactors are limited by the single-channel volume flux, and their volume is usually less than the mL / min level, and their actual processing capacity cannot meet the application requirements of industrial scale. At the same time, the two-phase flow in the microchannel of conventional microreactors is dominated by laminar flow, and the mass transfer process mainly relies on slow molecular diffusion mechanism. In addition, the interface renewal rate between the two phases is insufficient, resulting in a significant gap between the actual mass transfer coefficient and the theoretical limit. A more prominent problem is that conventional microreactors generally lack built-in phase separation function. After the extraction is completed, they need to rely on external phase separation equipment to achieve two-phase separation. This not only increases the complexity of the extraction system, but also seriously restricts the continuous production process. The above bottleneck problems have seriously restricted the promotion and application of conventional microreactors in industrial extraction scenarios.

[0003] In recent years, in order to enhance the mass transfer between two phases, there have been reports on microreactors that introduce external field energy such as ultrasonic vibration, electric field control, and magnetic field induction. By inputting external field energy to disturb the phase interface or control the fluid behavior, the mass transfer dynamics can be enhanced, and the mass transfer coefficient can be increased by 1~2 orders of magnitude compared with the case without external field effect. However, the existing microreactors that enhance mass transfer by introducing external field energy still have the following shortcomings that need to be improved: (1) Although the input of external field energy can promote the fragmentation and mixing of the dispersed phase, it cannot simultaneously achieve efficient separation of the two phases. The phase separation process still needs to rely on traditional means, such as using external phase separation equipment to achieve two-phase separation, resulting in low energy utilization efficiency; (2) When microreactors are scaled up in parallel, they face the problem of difficult coordinated control of the energy field. The energy attenuation and interference effects between multiple channels will aggravate the problem of uneven fluid distribution, further weakening the feasibility of their large-scale application. Therefore, there is an urgent need to develop microreactors that have both mass transfer enhancement and efficient phase separation functions to break through the technical barriers faced by current conventional microreactors in industrial scale-up and promote the application of microreactors in industrial extraction scenarios. Summary of the Invention

[0004] To address the problems that existing microreactors based on external field energy input cannot achieve efficient separation of two phases during liquid-liquid extraction, require additional phase separation equipment for phase separation, have low processing capacity and are difficult to scale up industrially, the present invention provides a rotating microreactor and a liquid-liquid extraction method to achieve continuous and efficient mass transfer and phase separation, and reduce the difficulty of industrial scale-up of the microreactor.

[0005] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is as follows: A rotating microreactor comprises a driving device, a rotating shaft, a housing, a rotating disc, a fixed ring and a centrifugal phase separation structure, wherein the housing comprises a lower housing and an upper housing; The rotating shaft consists of a rotating disc mounting section and a material conveying section that are connected to each other. The material conveying section is provided with a liquid inlet and is open at one end. The lower shell is a cylindrical body with both ends closed. The lower shell is provided with a mixing feed port, a rotating shaft inlet, and a rotating shaft outlet. There are N rotating discs and N-1 fixed rings, where N is an integer ≥ 2. Each rotating disc is horizontally mounted on the rotating disc mounting section, and each fixed ring is horizontally mounted on the inner side wall of the lower shell. The centrifugal phase separation structure is located above the lower shell body, and the centrifugal phase separation structure includes a separation cylinder and an upper shell body that is covered outside the separation cylinder. A separation cylinder feed port is provided at the center of the bottom of the separation cylinder; the lower end of the rotating shaft is connected to the driving device located below the lower shell body, and the upper end of the rotating shaft is connected to the separation cylinder feed port. The rotating disc mounting section and the liquid inlet are located in the lower shell body; each rotating disc and each fixed ring are arranged alternately; the axis of the lower shell body is perpendicular to the horizontal plane, and the axes of the rotating disc, fixed ring, rotating shaft and separation cylinder all coincide with the axis of the lower shell body; there are gaps between the fixed ring and the rotating shaft, between the rotating disc and the inner side wall of the lower shell body, and between adjacent rotating discs and fixed rings.

[0006] In the technical solution of the above-mentioned rotating microreactor, the separation cylinder is a cylindrical body with closed ends, a light phase outlet is provided on the upper end surface of the separation cylinder, and a heavy phase outlet is provided on the upper part of the side wall of the separation cylinder; the lower end of the upper shell is fixed to the top of the lower shell, and there is a gap between the inner wall of the upper shell and the separation cylinder, and a light phase weir, a heavy phase collection weir and a heavy phase collection port are provided on the upper shell; a first rotating seal is provided between the top of the heavy phase outlet and the inner side wall of the upper shell, and a second rotating seal is provided between the bottom of the heavy phase outlet and the heavy phase collection weir; a third rotating seal is provided in the gap between the rotating shaft and the rotating shaft inlet and rotating shaft outlet of the lower shell.

[0007] In the technical solution of the above-mentioned rotating microreactor, multiple heavy phase outlets are provided, and the heavy phase outlets are arranged at the same height position around the separation cylinder. The distance between each heavy phase outlet and the upper end surface of the separation cylinder is 0.5~10 cm, and the aperture of each heavy phase outlet is 1~20 mm. The aperture and number of the heavy phase outlets increase with the increase of the processing capacity of the rotating microreactor.

[0008] In the technical solution of the aforementioned rotary microreactor, multiple light-phase outlets are provided, each located on the upper end surface of the separation drum near the axis of the separation drum. Furthermore, each light-phase outlet is located no more than 0.5 times the drum diameter from the axis of the separation drum. The aperture of each light-phase outlet ranges from 1 to 20 mm, and the aperture and number of light-phase outlets increase with the processing capacity of the rotary microreactor. The light-phase chamber is defined by the upper end surface of the separation drum and the area between the first rotary seal and the top of the upper shell. The distance between the upper end surface of the separation drum and the top of the upper shell is typically 3 to 30 cm.

[0009] In the technical solution of the rotating microreactor, the width of the annular gap formed between the inner side wall of the upper shell and the outer side wall of the separation cylinder is 1 to 10 cm.

[0010] In the technical solution of the above-mentioned rotating microreactor, the heavy phase collecting weir is arranged on the inner side wall of the upper shell, and the heavy phase collecting weir is located below the heavy phase outlet and is arranged around the separation cylinder.

[0011] In the technical solution of the above rotary microreactor, the light phase weir is located above the first rotary seal; the heavy phase collection port is located on the upper shell between the first rotary seal and the second rotary seal, and the heavy phase collection port is connected to the heavy phase collection weir.

[0012] In the above-mentioned rotary microreactor technical solution, a baffle is provided within the separation drum, located near the feed inlet of the separation drum. Furthermore, the baffle is located in the middle of the lower portion of the separation drum. Typically, the vertical distance between the baffle and the feed inlet of the separation drum is 0.5 to 10 cm.

[0013] Furthermore, in the technical solution for the rotating microreactor, the baffle structure is designed with reference to the structure of baffles in existing centrifugal phase separation devices. For example, one feasible baffle structure is a radially radiating baffle, comprising multiple identical blades evenly distributed on a central axis, each blade extending outward radially from the central axis. The number of blades is 4 to 8, and the angle between adjacent blades is 45° to 90°. When the baffle is a radially radiating baffle, the central axis of the baffle is fixed to the inner wall of the separation drum via a fixing rod, such that the central axis of the baffle is parallel to the horizontal plane, and the center of the central axis of the baffle passes through the axis of the separation drum. Furthermore, the vertical distance between the tip of the baffle blade closest to the separation drum feed inlet and the separation drum feed inlet is 0.5 to 10 cm, and the distance between the tip of the baffle blade closest to the separation drum sidewall and the separation drum sidewall is 0.4 to 0.6 times the radius of the separation drum.

[0014] In the technical solution of the above-mentioned rotating microreactor, the distance between the inner side wall of the fixed ring and the outer wall of the rotating shaft is preferably 5~100 mm, the distance between the side wall of the rotating disk and the inner side wall of the lower shell is preferably 5~100 mm, and the distance between adjacent rotating disks and the fixed ring in the axial direction of the rotating shaft is preferably 0.5~100 mm.

[0015] In the technical solution of the rotating microreactor, the distance between the fixed ring and the adjacent rotating disk above it in the axial direction of the rotating shaft is 0.5 to 2 times the distance between the fixed ring and the adjacent rotating disk below it in the axial direction of the rotating shaft.

[0016] In the technical solution for the aforementioned rotating microreactor, a mounting hole with a diameter matching the diameter of the rotating disc mounting section of the rotating shaft is provided at the center of the rotating disc. The rotating disc is fixedly mounted to the rotating disc mounting section through the mounting hole. In other words, the rotating disc has a circular cross-section, and the diameter of the rotating disc refers to the outer diameter of this circular cross-section.

[0017] In the technical solution of the above-mentioned rotating microreactor, the thickness of the rotating disk is preferably 5-50 mm, the thickness of the fixed ring is preferably 5-50 mm, and the diameter of the rotating disk is preferably 4-150 cm.

[0018] In the technical solution of the above-mentioned rotating microreactor, the diameter and material of the rotating shaft are based on the principle that the mechanical strength of the rotating shaft meets the actual application requirements, that is, the diameter and material of the rotating shaft should ensure that the rotating shaft is not easily deformed or damaged during use. The diameter of the rotating shaft is positively correlated with the number and size of the rotating discs. Preferably, the diameter of the rotating shaft is 0.08 to 0.2 times the diameter of the rotating disc.

[0019] In the technical solution of the above-mentioned rotating microreactor, the fixed ring is located between adjacent rotating disks, that is, a fixed ring is provided between every two adjacent rotating disks, and thus the number of fixed rings is one less than the number of rotating disks. The number of rotating disks is preferably 2 to 25, that is, N is an integer between 2 and 25.

[0020] In the technical solution of the rotating microreactor, the structures of the rotating discs are identical. When the number of the fixed rings is ≥ 2, the structures of the fixed rings are identical.

[0021] In the technical solution of the above-mentioned rotating microreactor, the ratio of the inner diameter of the separation cylinder to the diameter of the rotating disk is preferably (0.6-0.9):1, and the ratio of the height of the separation cylinder to the diameter of the rotating disk is preferably (1-8):1. Typically, the height of the separation cylinder is 6-300 cm.

[0022] In the technical solution of the rotating microreactor described above, to enhance turbulence during the liquid-liquid two-phase mixing process within the high-speed shear field, the upper and / or lower surfaces of the rotating disk are provided with a plurality of annular or spiral grooves. When the grooves are annular, the axes of all grooves coincide with the axis of the rotating disk. When the grooves are spiral, the center points (starting points) of the grooves on the upper surface of the rotating disk are located at the center of the upper surface of the rotating disk, and the center points (starting points) of the grooves on the lower surface of the rotating disk are located at the center of the lower surface of the rotating disk. Furthermore, the width and depth of the grooves are both on the millimeter scale, for example, in the range of 0.2 to 10 mm. Furthermore, the groove width and depth can typically be 0.001 to 0.01 times the diameter of the rotating disk. Typically, the distance between adjacent grooves is 0.2 to 2 times the groove width.

[0023] In the technical solution of the rotary microreactor, the surface of the fixed ring is smooth.

[0024] In the technical solution of the above-mentioned rotating microreactor, the mixing feed port is preferably a T-shaped mixing feed port or a Y-shaped mixing feed port. Furthermore, the inner diameter of the channel of the mixing feed port can be 0.02 to 0.2 times the diameter of the rotating disk, and the inner diameter of the channel of the mixing feed port is generally 5 to 40 mm.

[0025] In the technical solution of the above-mentioned rotating microreactor, the rotating disc mounting section and the material conveying section of the rotating shaft are not interconnected. For example, the rotating disc mounting section is a solid structure, or both ends of the rotating disc mounting section are closed, while the material conveying section is a hollow structure with open ends.

[0026] In the above-mentioned rotary microreactor technical solution, the liquid inlet is located on the sidewall of the lower portion of the material conveying section. Multiple liquid inlets are provided, each arranged around the sidewall of the material conveying section. The aperture of the liquid inlet ranges from 0.5 to 20 mm. The aperture and number of liquid inlets increase with the processing capacity of the rotary microreactor.

[0027] In the technical solution of the above-mentioned rotating microreactor, the material of the rotating shaft, the upper shell, the lower shell, the rotating disc, the fixed ring, the separation cylinder and the upper shell is preferably duplex stainless steel.

[0028] In the technical solution of the above-mentioned rotating microreactor, the driving device may be a driving motor.

[0029] The rotary microreactor is supported and fixed by the support frame during operation, and the driving device is also supported and fixed by the support frame to ensure that the position of the rotary shaft remains stable during operation of the rotary microreactor.

[0030] The present invention also provides a liquid-liquid extraction method, which uses the above-mentioned rotary microreactor and comprises the following steps: ① Start the driving device to drive the rotating shaft to drive the rotating disc and separation cylinder to rotate; ② The extractant and the liquid to be extracted are continuously introduced into the lower shell from the mixed feed port, and the extractant and the liquid undergo liquid-liquid extraction reaction in the lower shell. Thereafter, the extractant and the liquid are continuously introduced into the separation cylinder from the material conveying section of the rotating shaft for centrifugal phase separation. After phase separation, the light phase and heavy phase continuously flow out of the rotating microreactor from the light phase weir and the heavy phase collection port respectively.

[0031] In the technical solution of the above-mentioned liquid-liquid extraction method, the rotation speed of the rotating shaft can be determined according to factors such as the material properties and phase ratio of the two phases to be subjected to liquid-liquid extraction, the size of the rotating microreactor, etc. Usually, the rotation speed of the rotating shaft can be controlled to be 500~3000 rpm.

[0032] The principles of the technical solution of the present invention are mainly as follows: The rotary microreactor of the present invention is characterized by arranging a plurality of alternately distributed rotating discs and fixed rings in a lower shell, arranging a separation cylinder in an upper shell, and cleverly utilizing a rotating shaft to couple the rotating discs in the lower shell and the separation cylinder in the upper shell. Driven by a driving device, the rotating shaft simultaneously drives the rotating discs and the separation cylinder to rotate to generate a cyclonic flow field. The shear force provided by the cyclonic flow field is utilized to achieve efficient mixing of liquid-liquid phases in the lower shell to promote the mass transfer process of extraction, and the centrifugal force provided by the cyclonic flow field can achieve efficient separation of the mixed phase after the mass transfer is completed.

[0033] On the one hand, the shear force provided by the cyclonic field in the microscale channel in the lower shell is used to fully disperse one phase into the other phase, reduce the size of the dispersed phase droplets, and increase the specific surface area of ​​contact between the dispersed phase and the continuous phase. At the same time, the introduced cyclonic field can change the laminar flow state of the liquid in the conventional microreactor into a turbulent flow state, strengthen the renewal and turbulence of the liquid-liquid interface, promote the renewal and redistribution of the concentration gradient in the two phases, enhance the mass transfer efficiency, and macroscopically manifest as shortening the liquid-liquid mass transfer time and improving the processing capacity of the microreactor. On the other hand, the mixed phase after mass transfer is introduced into the separation cylinder. Under the action of the centrifugal force provided by the cyclonic field to the separation cylinder, the two phases in the mixed phase will be subjected to different centrifugal accelerations in the separation cylinder due to their different densities, so that the heavy phase with high density is enriched in the area near the side wall of the separation cylinder, and the light phase with low density is enriched in the area near the axis of the separation cylinder, thereby achieving rapid separation of the liquid-liquid two phases. Under the influence of the above two factors, the present invention effectively couples the mixing and phase separation operations in the microreactor, realizing continuous mass transfer and phase separation. Compared with the separate mixing + separate separation operation mode adopted in the prior art, the present invention can reduce the number of equipment and the floor space, and save energy consumption and costs for operation and running.

[0034] At the same time, the present invention can increase the processing capacity of the microreactor exponentially by increasing the number of rotating disks and fixed rings, and can increase the processing capacity of the microreactor according to a square multiple by increasing the size of the rotating disk. The combination of these two aspects significantly improves the processing capacity of the microreactor, thereby realizing the industrial scale-up of the microreactor, which can effectively solve the problems faced by conventional microreactors in industrial scale-up and parallel scale-up.

[0035] Compared with the prior art, the technical solution provided by the present invention produces the following beneficial technical effects: The present invention provides a rotating microreactor and a liquid-liquid extraction method. The invention comprises a plurality of alternating rotating disks and fixed rings disposed within a lower housing, a separation drum disposed within an upper housing, and a rotating shaft cleverly coupled the rotating disks within the lower housing to the separation drum within the upper housing. Driven by a driving device, the rotating shaft simultaneously drives the rotating disks and the separation drum to rotate, generating a cyclonic flow field. The shear force and centrifugal force provided by the cyclonic flow field achieve efficient mixing and separation of liquid-liquid phases in the lower and upper housings, respectively. On the one hand, the shear force provided by the cyclonic flow field in the microscale channels within the lower housing promotes the full dispersion of one phase in the other, reduces the size of the dispersed phase droplets, and increases the specific surface area of ​​contact between the two phases. Simultaneously, the introduction of the cyclonic flow field enhances the renewal and turbulence of the liquid-liquid interface, prompting the renewal and redistribution of the concentration gradients within the two phases, thereby enhancing mass transfer efficiency and shortening mass transfer time. On the other hand, the centrifugal force provided by the cyclonic flow field within the separation drum allows the two phases in the mixed phase after mass transfer to undergo rapid phase separation due to different centrifugal accelerations. The above factors enable the microreactor of the present invention to achieve continuous and efficient mass transfer and phase separation. Compared with the existing technology of operating the mixing and phase separation processes separately, the present invention can reduce the number of equipment and floor space, and save energy consumption and costs for operation and running.

[0036] 2. The rotary microreactor of the present invention can increase the processing capacity of the microreactor by multiples by increasing the number of rotating discs and fixed rings, and can amplify the processing capacity of the microreactor according to the relationship of square multiples by increasing the size of the rotating disc. This dual mode of "quantity amplification" + "size amplification" can significantly increase the processing capacity of the microreactor and realize industrial amplification of the microreactor. Taking phosphoric acid extraction as an example, the present invention has confirmed through experiments that after the rotary microreactor of the present invention is amplified to an industrial level, there is basically no adverse effect on the phosphoric acid extraction effect. The present invention can break through the technical bottleneck of conventional microreactors with small single-channel processing capacity and multiple parallel microchannels that easily cause uneven fluid distribution, making it difficult to achieve industrial amplification. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a structural schematic diagram of the rotary microreactor of the present invention.

[0038] Figure 2 It is a schematic structural diagram of the rotating shaft of the rotary microreactor of the present invention.

[0039] Figure 3 It is a structural schematic diagram of the upper and lower surfaces of the rotating disk of the rotary microreactor of the present invention.

[0040] Figure 4 It is a structural schematic diagram of the upper end surface of the separation cylinder of the rotary microreactor of the present invention.

[0041] Figure 5 Schematic diagram of using the rotary microreactor of the present invention for phosphoric acid extraction.

[0042] In the figure, 1 is a driving device, 2 is a rotating shaft, 201 is a rotating disc mounting section, 202 is a material conveying section, 203 is a liquid inlet, 3 is a lower shell, 4 is a rotating disc, 5 is a fixed ring, 6 is a mixed feed port, 7 is a separation cylinder, 8 is an upper shell, 9 is a light phase outlet, 10 is a heavy phase outlet, 11 is a light phase weir, 12 is a heavy phase collecting weir, 13 is a heavy phase collecting port, 14 is a first rotating seal, 15 is a second rotating seal, 16 is a third rotating seal, 17 is a baffle, 18 is a groove, 19 is an extractant storage tank, 20 is a first delivery pump, 21 is a liquid storage tank, and 22 is a second delivery pump. DETAILED DESCRIPTION

[0043] The following examples further illustrate the rotary microreactor and liquid-liquid extraction method provided by the present invention. It is important to note that the following examples are intended only to further illustrate the present invention and are not to be construed as limiting the scope of the present invention. Based on the above disclosure, non-essential improvements and adjustments made by those skilled in the art to the present invention for implementation remain within the scope of the present invention.

[0044] Example 1 In this embodiment, a rotating microreactor is provided, and the structural schematic diagram of the rotating microreactor is shown as follows: Figure 1 As shown, it includes a driving device 1, a rotating shaft 2, a housing, a rotating disc 4, a fixed ring 5 and a centrifugal phase separation structure, and the housing includes a lower housing 3 and an upper housing 8.

[0045] The rotating shaft 2 is composed of a rotating disc mounting section 201 and a material conveying section 202 that are connected to each other. The material conveying section 202 is a hollow structure with an open end. A liquid inlet 203 is provided on the material conveying section 202. The liquid inlet 203 is located at the lower part of the side wall of the material conveying section 202. There are multiple liquid inlets 203, and each liquid inlet 203 is arranged around the side wall of the material conveying section 202. Figure 2The rotating disc installation section 201 is a solid structure, and the material conveying section 202 is a hollow structure with both ends open, that is, the rotating disc installation section 201 and the material conveying section 202 are not connected to each other.

[0046] The lower housing 3 is a cylindrical body with closed ends. Specifically, it consists of a closed upper end and an open lower end, and a removable lower cover mounted on the lower end of the cylinder to facilitate maintenance, repair, and replacement of the lower housing's internal components. A mixing inlet 6 and a rotating shaft inlet are located at the bottom of the lower housing 3, while the rotating shaft outlet is located at the top. The mixing inlet 6 is T-shaped and equipped with a control valve, located near the center of the lower housing's bottom.

[0047] There are three rotating disks 4, and each rotating disk 4 has the same structure. There are two fixed disks 5, and each fixed disk 5 has the same structure. The surfaces of the rotating disk 4 and the fixed ring 5 are smooth. The center of each rotating disk 4 is provided with a mounting hole whose size matches the diameter of the rotating disk mounting section 202 of the rotating shaft 2. Each rotating disk 4 is fixedly mounted on the rotating disk mounting section 202 of the rotating shaft 2 through the mounting hole, and each rotating disk 4 is horizontally mounted on the rotating disk mounting section 202. The large radius of each fixed ring 5 matches the inner diameter of the lower shell 3, the outer side wall of each fixed ring 5 is fixed to the inner side wall of the lower shell 3, and each fixed ring 5 is horizontally mounted on the inner side wall of the lower shell 3.

[0048] The centrifugal phase separation structure consists of an upper shell 8 and a separation cylinder 7. The separation cylinder 7 is a cylindrical body with both ends closed. A separation cylinder feed port is provided at the center of the bottom of the separation cylinder 7. The separation cylinder 7 is also provided with a light phase outlet 9 and a heavy phase outlet 10. There are multiple light phase outlets 9, each of which is located in the area of ​​the upper end surface of the separation cylinder 7 close to the axis of the separation cylinder 7, such as Figure 4There are multiple heavy phase outlets 10, each located at the upper portion of the side wall of the separation cylinder, and each heavy phase outlet 10 is arranged at the same height around the side wall of the separation cylinder 7. The upper shell 8 is covered outside the separation cylinder 7, and the lower end of the upper shell 8 is fixed to the top of the lower shell 3. There is a gap between the inner wall of the upper shell 8 and the separation cylinder 7. The upper shell 8 is provided with a light phase weir 11, a heavy phase collection weir 12 and a heavy phase collection port 13. The heavy phase collection weir 12 is arranged on the inner wall of the upper shell 8. The heavy phase collection weir 12 is located below the heavy phase outlet 10 and is arranged around the separation cylinder 7. More specifically, a circular ring is fixed on the inner wall of the upper shell 8, which is located below the heavy phase outlet 10. The axis of the circular ring coincides with the axis of the separation cylinder 7. The outer wall of the circular ring is fixed on the inner wall of the upper shell 8. The inner wall of the circular ring is close to the outer wall of the separation cylinder 7. The gap between the inner wall of the circular ring and the separation cylinder 7 is sealed by the second rotary seal 15. The area above the circular ring and between the outer wall below the heavy phase outlet 10 of the separation cylinder 7 and the inner wall of the outer shell 8 is the heavy phase collection weir 12. The light phase weir 11 is located above the first rotating seal 14, and the heavy phase collection port 13 is located on the upper shell between the first rotating seal 14 and the second rotating seal 15. The heavy phase collection port 13 is connected to the heavy phase collection weir 12. A first rotating seal 14 is installed between the upper side of the heavy phase outlet 10 of the separation drum 7 and the inner sidewall of the upper shell 8. A second rotating seal 15 is installed between the lower side of the heavy phase outlet 10 of the separation drum 7 and the heavy phase collection weir 12. A third rotating seal 16 is installed in the gap between the rotating shaft 2 and the rotating shaft inlet and the rotating shaft outlet of the lower shell 3. A baffle 17 is installed inside the separation drum 7, located near the separation drum feed port and in the middle of the lower portion of the separation drum 7. The baffle 17 is a radially radiating baffle. The baffle 17 includes four blades of identical structure, each blade evenly distributed on a central axis. Each blade extends outward in the radial direction of the central axis, and the angle between adjacent blades is 90°. The baffle 17 is fixed to the inner wall of the separation cylinder by a fixing rod through the central axis. After fixing, the central axis is parallel to the horizontal plane and the center of the central axis passes through the axis of the separation cylinder 7.

[0049] The centrifugal phase separation structure is located above the lower shell 3, and the drive unit 1 is located below the lower shell 3. The lower end of the rotating shaft 2 is connected to the drive unit 1, and the upper end of the rotating shaft 2 is connected to the feed port of the separation drum. The rotating disc mounting section 201 and the liquid inlet 203 are located in the lower shell 3. The rotating discs 4 and the fixed rings 5 ​​are arranged alternately, and the fixed rings 5 ​​are located between adjacent rotating discs 4, that is, a fixed ring 5 is provided between every two adjacent rotating discs 4. The axis of the lower shell 3 is perpendicular to the horizontal plane, and the axes of the upper shell 8, the rotating discs 4, the fixed rings 5, the rotating shaft 2, and the separation drum 7 all coincide with the axis of the lower shell 3. There are gaps between the fixed rings 5 ​​and the rotating shaft 2, between the rotating discs 4 and the inner side wall of the lower shell 3, and between adjacent rotating discs 4 and the fixed rings 5.

[0050] The rotating microreactor is supported and fixed by a support frame, and the driving device 1 is also supported and fixed by the support frame to ensure that the position of the rotating shaft 2 is stable during the operation of the rotating microreactor.

[0051] More specifically: The rotating disk 4 has a diameter of 4 cm and a thickness of 5 mm; the fixed ring 5 has a width of 1.6 cm and a thickness of 5 mm; the inner diameter of the lower housing 3 is 5 cm; the diameters of the rotating disk mounting section 201 and the material conveying section 202 of the rotating shaft 2 are 8 mm, and the aperture of the liquid inlet 203 is 0.5 mm. In other words, the distance between the sidewall of the rotating disk 4 and the inner sidewall of the lower housing 3 is 5 mm, and the distance between the inner sidewall of the fixed ring 5 and the outer wall of the rotating shaft 2 is 5 mm. The distance between the uppermost rotating disk 4 and the upper end of the lower housing 3 is 2 cm, and the distance between the lowermost rotating disk 4 and the lower end of the lower housing 3 is 1 cm. The distance between each fixed ring 5 and the rotating disk 4 adjacent and above it, along the axis of the rotating shaft 2, is 0.5 mm, and the distance between each fixed ring 5 and the rotating disk 4 adjacent and below it, along the axis of the rotating shaft 2, is 1 mm. The inner diameter of the channel of the mixing feed port 8 is 5 mm.

[0052] The inner diameter of the separation cylinder 7 is 2.5 cm, the height of the separation cylinder 7 is 6 cm, the width of the annular gap formed between the inner wall of the upper shell 8 and the outer wall of the separation cylinder 7 is 1 cm, and the distance between the upper end face of the separation cylinder 7 and the top of the upper shell 3 is 3 cm. The distance between the heavy phase outlet 10 and the upper end face of the separation cylinder 7 is 1 cm, and the aperture of the heavy phase outlet 10 is 1 mm. The aperture of the light phase outlet 9 is 1 mm. The vertical distance between the end of the blade closest to the separation cylinder feed inlet in the baffle 17 and the separation cylinder feed inlet is 0.5 cm, and the distance between the end of the blade closest to the side wall of the separation cylinder 7 in the baffle 17 and the side wall of the separation cylinder 7 is 0.6 times the radius of the separation cylinder 7.

[0053] The rotating shaft 2, lower housing 3, upper housing 8, rotating disc 4, fixed ring 5 and separation cylinder 7 are all made of duplex stainless steel. The driving device 1 is a driving motor that drives the rotating shaft 2 to rotate the rotating disc 4 and separation cylinder 7.

[0054] Example 2 In this embodiment, a rotary microreactor is provided, the structure of which is substantially the same as that of the rotary microreactor in Example 1, except that: There are two rotating discs 4, each with the same structure, and one fixed ring 5. Figure 3 As shown, a plurality of annular grooves 18 are provided on the upper and lower surfaces of each rotating disk 4 , and the axes of all the grooves 18 coincide with the axis of the rotating disk 4 .

[0055] The rotating disc 4 has a diameter of 25 cm and a thickness of 10 mm. The grooves 18 on the upper and lower surfaces of the rotating disc 4 have rectangular cross-sections, a width of 1.5 mm, a depth of 1 mm, and a distance of 3 mm between adjacent grooves 18. The fixed ring 5 has a width of 8 cm and a thickness of 10 mm. The lower housing 3 has an inner diameter of 27 cm. The diameters of the rotating disc mounting section 201 and the material conveying section 202 of the rotating shaft 2 are 2 cm, and the aperture of the liquid inlet 203 is 1 mm. In other words, the distance between the sidewall of the rotating disc 4 and the inner wall of the lower housing 3 is 10 mm, and the distance between the inner wall of the fixed ring 5 and the outer wall of the rotating shaft 2 is 45 mm. The distance between the uppermost rotating disc 4 and the upper end of the lower shell 3 is 4 cm, and the distance between the lowermost rotating disc 4 and the lower end of the lower shell 3 is 2 cm. The distance between each fixed ring 5 and the rotating disc 4 adjacent to and located above it along the axis of the rotating shaft 2 is 2 mm, and the distance between each fixed ring 5 and the rotating disc 4 adjacent to and located below it along the axis of the rotating shaft 2 is 5 mm. The inner diameter of the channel of the mixing feed port 8 is 10 mm.

[0056] The inner diameter of the separation cylinder 7 is 15 cm, the height of the separation cylinder 7 is 30 cm, the width of the annular gap formed between the inner wall of the upper shell 8 and the outer wall of the separation cylinder 7 is 2.5 cm, and the distance between the upper end face of the separation cylinder 7 and the top of the upper shell 8 is 3 cm. The distance between the heavy phase outlet 10 and the upper end face of the separation cylinder 7 is 0.5 cm, and the aperture of the heavy phase outlet 10 is 2 mm. The aperture of the light phase outlet 9 is 2 mm. The vertical distance between the end of the blade closest to the separation cylinder feed inlet in the baffle 17 and the separation cylinder feed inlet is 0.5 cm, and the distance between the end of the blade closest to the side wall of the separation cylinder 7 in the baffle 17 and the side wall of the separation cylinder 7 is 0.5 times the radius of the separation cylinder 7.

[0057] Example 3 In this embodiment, a rotary microreactor is provided, the structure of which is substantially the same as that of the rotary microreactor in Example 1, except that: The mixing feed port 6 is a Y-shaped mixing feed port; the number of rotating discs 4 is 10, each rotating disc 4 has the same structure, and the number of fixed rings 5 ​​is 9; Figure 3 As shown, a plurality of annular grooves 18 are provided on the upper and lower surfaces of each rotating disk 4 , and the axes of all the grooves 18 coincide with the axis of the rotating disk 4 .

[0058] The rotating disc 4 has a diameter of 100 cm and a thickness of 15 mm. The grooves 18 on the upper and lower surfaces of the rotating disc 4 are rectangular in cross-section, 5 mm wide and 2.5 mm deep, with a distance of 5 mm between adjacent grooves 18. The fixed ring 5 has a width of 40 cm and a thickness of 15 mm. The inner diameter of the lower housing 3 is 110 cm. The diameters of the rotating disc mounting section 201 and the material conveying section 202 of the rotating shaft 2 are both 10 cm, and the aperture of the liquid inlet 203 is 10 mm. In other words, the distance between the sidewall of the rotating disc 4 and the inner wall of the lower housing 3 is 5 cm, and the distance between the inner wall of the fixed ring 5 and the outer wall of the rotating shaft 2 is 10 cm. The distance between the uppermost rotating disc 4 and the upper end of the lower shell 3 is 5 cm, and the distance between the lowermost rotating disc 4 and the lower end of the lower shell 3 is 3 cm. The distance between each fixed ring 5 and the rotating disc 4 adjacent to and located above it along the axis of the rotating shaft 2 is 15 mm, and the distance between each fixed ring 5 and the rotating disc 4 adjacent to and located below it along the axis of the rotating shaft 2 is 30 mm. The inner diameter of the channel of the mixing feed port 8 is 15 mm.

[0059] The inner diameter of the separation cylinder 7 is 75 cm, the height of the separation cylinder 7 is 150 cm, the width of the annular gap formed between the inner wall of the upper shell 8 and the outer wall of the separation cylinder 7 is 10 cm, and the distance between the upper end face of the separation cylinder 7 and the top of the upper shell 3 is 8 cm. The distance between the heavy phase outlet 10 and the upper end face of the separation cylinder 7 is 10 cm, and the aperture of the heavy phase outlet 10 is 10 mm. The aperture of the light phase outlet 9 is 10 mm. The vertical distance between the end of the blade closest to the separation cylinder feed inlet in the baffle 17 and the separation cylinder feed inlet is 5 cm, and the distance between the end of the blade closest to the side wall of the separation cylinder 7 in the baffle 17 and the side wall of the separation cylinder 7 is 0.5 times the radius of the separation cylinder 7.

[0060] Example 4 In this embodiment, a rotary microreactor is provided, the structure of which is substantially the same as that of the rotary microreactor in Example 1, except that: The number of rotating discs 4 is 25, and the structure of each rotating disc 4 is the same, and the number of fixed rings 5 ​​is 24; Figure 3 As shown, a plurality of annular grooves 18 are provided on the upper and lower surfaces of each rotating disk 4 , and the axes of all the grooves 18 coincide with the axis of the rotating disk 4 .

[0061] The rotating disc 4 has a diameter of 25 cm and a thickness of 10 mm. The grooves 18 on the upper and lower surfaces of the rotating disc 4 have rectangular cross-sections, a width of 1.5 mm, a depth of 1 mm, and a distance of 3 mm between adjacent grooves 18. The fixed ring 5 has a width of 7 cm and a thickness of 10 mm. The inner diameter of the lower housing 3 is 27 cm. The diameters of the rotating disc mounting section 201 and the material conveying section 202 of the rotating shaft 2 are 5 cm, and the aperture of the liquid inlet 203 is 5 mm. In other words, the distance between the sidewall of the rotating disc 4 and the inner wall of the lower housing 3 is 10 mm, and the distance between the inner wall of the fixed ring 5 and the outer wall of the rotating shaft 2 is 45 mm. The distance between the uppermost rotating disc 4 and the upper end of the lower shell 3 is 6 cm, and the distance between the lowermost rotating disc 4 and the lower end of the lower shell 3 is 2 cm. The distance between each fixed ring 5 and the rotating disc 4 adjacent to and located above it along the axis of the rotating shaft 2 is 2 mm, and the distance between each fixed ring 5 and the rotating disc 4 adjacent to and located below it along the axis of the rotating shaft 2 is 5 mm. The inner diameter of the channel of the mixing feed port 8 is 20 mm.

[0062] The inner diameter of the separation cylinder 7 is 20 cm, the height of the separation cylinder 7 is 200 cm, the width of the annular gap formed between the inner wall of the upper shell 8 and the outer wall of the separation cylinder 7 is 2.5 cm, and the distance between the upper end face of the separation cylinder 7 and the top of the upper shell 8 is 10 cm. The distance between the heavy phase outlet 10 and the upper end face of the separation cylinder 7 is 3 cm, and the aperture of the heavy phase outlet 10 is 10 mm. The aperture of the light phase outlet 9 is 10 mm. The vertical distance between the end of the blade closest to the separation cylinder feed inlet in the baffle 17 and the separation cylinder feed inlet is 0.5 cm, and the distance between the end of the blade closest to the side wall of the separation cylinder 7 in the baffle 17 and the side wall of the separation cylinder 7 is 0.5 times the radius of the separation cylinder 7.

[0063] Example 5 In this embodiment, a rotary microreactor is provided, the structure of which is substantially the same as that of the rotary microreactor in Example 1, except that: The number of rotating discs 4 is 5, and the structure of each rotating disc 4 is the same, and the number of fixed rings 5 ​​is 4; Figure 3As shown, the upper and lower surfaces of each rotating disk 4 are provided with a plurality of annular grooves 18, the axes of all grooves 18 coinciding with the axis of the rotating disk 4. The baffle 17 is a radially radiating baffle, comprising eight identical blades, evenly distributed about a central axis. Each blade extends outward radially from the central axis, with an angle of 45° between adjacent blades.

[0064] The rotating disc 4 has a diameter of 150 cm and a thickness of 50 mm. The grooves 18 on the upper and lower surfaces of the rotating disc 4 are rectangular in cross-section, 10 mm wide and 10 mm deep, with a distance of 2 mm between adjacent grooves 18. The fixed ring 5 has a width of 70 cm and a thickness of 50 mm. The inner diameter of the lower housing 3 is 170 cm. The diameters of the rotating disc mounting section 201 and the material conveying section 202 of the rotating shaft 2 are 20 cm, and the aperture of the liquid inlet 203 is 20 mm. In other words, the distance between the sidewall of the rotating disc 4 and the inner wall of the lower housing 3 is 10 cm, and the distance between the inner wall of the fixed ring 5 and the outer wall of the rotating shaft 2 is 5 cm. The distance between the uppermost rotating disc 4 and the upper end of the lower shell 3 is 10 cm, and the distance between the lowermost rotating disc 4 and the lower end of the lower shell 3 is 5 cm. The distance between each fixed ring 5 and the rotating disc 4 adjacent to and located above it along the axis of the rotating shaft 2 is 10 cm, and the distance between each fixed ring 5 and the rotating disc 4 adjacent to and located below it along the axis of the rotating shaft 2 is also 10 cm. The inner diameter of the channel of the mixing feed port 8 is 40 mm.

[0065] The inner diameter of the separation cylinder 7 is 135 cm, the height of the separation cylinder 7 is 150 cm, the width of the annular gap formed between the inner wall of the upper shell 8 and the outer wall of the separation cylinder 7 is 5 cm, and the distance between the upper end face of the separation cylinder 7 and the top of the upper shell 8 is 30 cm. The distance between the heavy phase outlet 10 and the upper end face of the separation cylinder 7 is 10 cm, and the aperture of the heavy phase outlet 10 is 20 mm. The aperture of the light phase outlet 9 is 20 mm. The vertical distance between the end of the blade closest to the separation cylinder feed inlet in the baffle 17 and the separation cylinder feed inlet is 10 cm, and the distance between the end of the blade closest to the side wall of the separation cylinder 7 in the baffle 17 and the side wall of the separation cylinder 7 is 0.4 times the radius of the separation cylinder 7.

[0066] Example 6 In this embodiment, phosphoric acid extraction is taken as an example to illustrate the liquid-liquid extraction method of the present invention.

[0067] A mixture of tributyl phosphate and kerosene was used as an extractant, with a volume ratio of tributyl phosphate to kerosene of 8:2 in the extractant, and a phosphoric acid aqueous solution with a P2O5 mass content of 46% as the feed liquid to be extracted. The rotary microreactor in Example 1 was used. The extractant was placed in an extractant storage tank 19, which was connected to one inlet of a T-type mixed feed port via a pipe fitting through a first delivery pump 20. The feed liquid to be extracted was placed in a feed liquid storage tank 21, which was connected to the other inlet of the T-type mixed feed port via a pipe fitting through a second delivery pump 22, as shown in FIG. Figure 5 As shown, the steps are as follows: ① Start the driving device of the rotating microreactor to drive the rotating shaft to drive the rotating disc and the separation cylinder to rotate around the axis of the rotating shaft at a speed of 1500 rpm.

[0068] ② The extractant and the liquid to be extracted are continuously introduced into the lower shell by the first delivery pump and the second delivery pump through the T-shaped mixing feed port, respectively. The volume flow rate of the extractant is controlled to be 250 mL / min, and the volume flow rate of the liquid to be extracted is controlled to be 50 mL / min. The extractant and the liquid undergo liquid-liquid extraction reaction in the lower shell, and then are continuously introduced into the separation cylinder by the material delivery section of the rotating shaft for centrifugal phase separation. The light phase and heavy phase after phase separation continuously flow out of the rotating microreactor through the light phase outlet and the heavy phase outlet respectively. After the rotating microreactor has been running continuously for 30 minutes, the residual phase is taken and the mass fraction of P2O5 therein is detected according to the method of GB / T 23843-2009, and the extraction rate is calculated according to the following formula w The results show that the extraction rate of phosphoric acid in this embodiment is 65.4%.

[0069] w =( m 1 c 1- m 2 c 2) / m 1 c 1×100% In the above formula, m 1 is the weight of the liquid to be extracted, c 1 is the mass fraction of P2O5 in the liquid to be extracted, m 2 is the weight of the raffinate phase, c 2 is the mass fraction of P2O5 in the raffinate phase.

[0070] Example 7 In this embodiment, phosphoric acid extraction is taken as an example to illustrate the liquid-liquid extraction method of the present invention.

[0071] A mixture of tributyl phosphate and kerosene was used as the extractant, with a volume ratio of tributyl phosphate to kerosene of 8:2. A phosphoric acid aqueous solution with a P2O5 mass content of 46% was used as the feed liquid to be extracted. The rotary microreactor described in Example 2 was used. The extractant was placed in an extractant storage tank 19, which was connected to one inlet of a T-type mixed feed port via a pipe fitting via a first delivery pump 20. The feed liquid to be extracted was placed in a feed liquid storage tank 21, which was connected to the other inlet of the T-type mixed feed port via a pipe fitting via a second delivery pump 22. The steps were as follows: ① Start the driving device of the rotating microreactor to drive the rotating shaft to drive the rotating disc and the separation cylinder to rotate around the axis of the rotating shaft at a speed of 1200 rpm.

[0072] ② The extractant and the liquid to be extracted are continuously introduced into the lower shell by the first delivery pump and the second delivery pump through the T-shaped mixing feed port, respectively. The volume flow rate of the extractant is controlled to be 300 mL / min, and the volume flow rate of the liquid to be extracted is controlled to be 60 mL / min. The extractant and the liquid undergo liquid-liquid extraction reaction in the lower shell, and then are continuously introduced into the separation cylinder by the material delivery section of the rotating shaft for centrifugal phase separation. The light phase and heavy phase after phase separation continuously flow out of the rotating microreactor from the light phase outlet and the heavy phase outlet respectively.

[0073] After the rotary microreactor was continuously operated for 30 min, the raffinate phase was taken and the mass fraction of P2O5 therein was determined according to the method of GB / T 23843-2009, and the extraction rate was calculated according to the method in Example 6. w The results show that the extraction rate of phosphoric acid in this embodiment is 65.3%.

[0074] Comparative Example 1 In this comparative example, a phosphoric acid extraction experiment was carried out in a beaker.

[0075] A mixture of tributyl phosphate and kerosene was used as the extractant, the volume ratio of tributyl phosphate to kerosene in the extractant was 8:2, and a phosphoric acid aqueous solution with a P2O5 mass content of 46% was used as the feed liquid to be extracted.

[0076] 1500 mL of extractant and 300 mL of the liquid to be extracted were added to a beaker, and the material in the beaker was stirred at 1500 rpm at room temperature for liquid-liquid extraction reaction. The stirring time was controlled to 8 s, after which the stirring was stopped and the phases were allowed to stand to separate, obtaining an extract phase and a raffinate phase.

[0077] The mass fraction of P2O5 in the extract was determined according to the method of GB / T 23843-2009, and the extraction rate was calculated according to the method in Example 6. wThe results showed that the extraction rate of phosphoric acid in this comparative example was 25.4%. At the same time, during the experiment, it was found that after stopping stirring, it took 66 minutes to achieve phase separation.

[0078] Comparative Example 2 In this comparative example, a phosphoric acid extraction experiment was carried out in a beaker.

[0079] A mixture of tributyl phosphate and kerosene was used as the extractant, the volume ratio of tributyl phosphate to kerosene in the extractant was 8:2, and a phosphoric acid aqueous solution with a P2O5 mass content of 46% was used as the feed liquid to be extracted.

[0080] 1500 mL of extractant and 300 mL of the liquid to be extracted were added to a beaker, and the material in the beaker was stirred at 1500 rpm at room temperature for liquid-liquid extraction reaction. The stirring time was controlled to be 30 min, after which the stirring was stopped and the phases were allowed to stand to separate to obtain the extract phase and the raffinate phase.

[0081] The mass fraction of P2O5 in the extract was determined according to the method of GB / T 23843-2009, and the extraction rate was calculated according to the method in Example 6. w The results showed that the extraction rate of phosphoric acid in this comparative example was 65.1%. At the same time, during the experiment, it was found that it took 82 minutes of standing after stopping stirring to achieve phase separation.

[0082] Combining Example 7 and Comparative Examples 1 and 2, it can be seen that the method of the present invention can significantly shorten the phase separation time compared to extracting the extractant and the feed liquid directly under stirring. Furthermore, to achieve a comparable extraction rate, under the flow conditions of Example 7, the residence time of the extractant and the feed liquid in the housing does not exceed 60 seconds, while Comparative Example 2 requires the extractant and the feed liquid to be stirred and extracted for 30 minutes. This demonstrates that the method of the present invention can significantly shorten the extraction time and improve the extraction efficiency.

[0083] Comparative Example 3 In this comparative example, a phosphoric acid extraction experiment was carried out in a T-shaped coil microchannel.

[0084] The T-shaped coil microchannel used in this comparative example had a microchannel width of 0.5 mm, a microchannel depth of 0.5 mm, and a microchannel length of 100 cm. A mixture of tributyl phosphate and kerosene was used as the extractant, with a volume ratio of tributyl phosphate to kerosene of 8:2. An aqueous phosphoric acid solution containing 46% P₂O₅ was used as the extractant.

[0085] The extractant and the liquid to be extracted were respectively continuously introduced into the T-shaped coil microchannel by a delivery pump, the volume flow rate of the extractant was controlled at 1500 mL / min, and the volume flow rate of the liquid to be extracted was controlled at 300 mL / min. The extractant and the liquid underwent a liquid-liquid extraction reaction in the T-shaped coil microchannel, and then continuously discharged from the T-shaped coil microchannel and collected in a collection tank for phase separation.

[0086] After the T-shaped coil microchannel was continuously operated for 30 min, the raffinate was taken and the mass fraction of P2O5 was determined according to the method of GB / T 23843-2009, and the extraction rate was calculated according to the method in Example 6. w The results showed that the extraction rate of phosphoric acid in this comparative example was 33.7%. At the same time, during the experiment, it was found that the material discharged from the T-coil microchannel needed to be left to stand for 14 minutes after entering the collection tank before phase separation could be achieved.

[0087] Combining Example 7 and Comparative Example 3, it can be seen that the method of the present invention can effectively shorten the phase separation time and effectively improve the extraction rate under the same processing volume when the liquid-liquid extraction of phosphoric acid is also carried out using a microreactor.

[0088] Example 8 In this embodiment, phosphoric acid extraction is taken as an example to illustrate the liquid-liquid extraction method of the present invention.

[0089] A mixture of tributyl phosphate and kerosene was used as the extractant, with a volume ratio of tributyl phosphate to kerosene of 8:2 in the extractant, and a phosphoric acid aqueous solution with a P2O5 mass content of 46% as the feed liquid to be extracted. The rotary microreactor in Example 3 was used. The extractant was placed in an extractant storage tank 19, which was connected to one inlet of the Y-type mixed feed port via a pipe fitting through a first delivery pump 20. The feed liquid to be extracted was placed in a feed liquid storage tank 21, which was connected to the other inlet of the Y-type mixed feed port via a pipe fitting through a second delivery pump 22, as shown in FIG. Figure 5 As shown, the steps are as follows: ① Start the driving device of the rotating microreactor to drive the rotating shaft to drive the rotating disc and the separation cylinder to rotate around the axis of the rotating shaft at a speed of 1500 rpm.

[0090] ② The extractant and the liquid to be extracted are continuously introduced into the lower shell through the Y-type mixing feed port by the first delivery pump and the second delivery pump respectively, and the volume flow rate of the extractant is controlled to be 30 m 3 / h, and the volume flow rate of the liquid to be extracted is controlled to be 6 m 3 / h, the extractant and the feed liquid undergo liquid-liquid extraction reaction in the lower shell, and then are continuously passed into the separation cylinder through the material conveying section of the rotating shaft for centrifugal phase separation. The light phase and heavy phase after phase separation continuously flow out of the rotating microreactor through the light phase outlet and the heavy phase outlet respectively.

[0091] After the rotary microreactor was continuously operated for 30 min, the raffinate phase was taken and the mass fraction of P2O5 therein was determined according to the method of GB / T 23843-2009, and the extraction rate was calculated according to the method in Example 6. w The results show that the extraction rate of phosphoric acid in this embodiment is 63.9%.

[0092] Example 9 In this embodiment, phosphoric acid extraction is taken as an example to illustrate the liquid-liquid extraction method of the present invention.

[0093] A mixture of tributyl phosphate and kerosene was used as the extractant, with a volume ratio of tributyl phosphate to kerosene of 8:2. A phosphoric acid aqueous solution with a P2O5 mass content of 46% was used as the feed liquid to be extracted. The rotary microreactor described in Example 4 was used. The extractant was placed in an extractant storage tank 19, which was connected to one inlet of a T-type mixed feed port via a pipe fitting via a first delivery pump 20. The feed liquid to be extracted was placed in a feed liquid storage tank 21, which was connected to the other inlet of the T-type mixed feed port via a pipe fitting via a second delivery pump 22. The steps were as follows: ① Start the driving device of the rotating microreactor to drive the rotating shaft to drive the rotating disc and the separation cylinder to rotate around the axis of the rotating shaft at a speed of 600 rpm.

[0094] ② The extractant and the liquid to be extracted are continuously introduced into the lower shell by the first delivery pump and the second delivery pump through the T-shaped mixing feed port, respectively. The volume flow rate of the extractant is controlled to be 250 L / h, and the volume flow rate of the liquid to be extracted is controlled to be 50 L / h. The extractant and the liquid undergo liquid-liquid extraction reaction in the lower shell, and then are continuously introduced into the separation cylinder by the material delivery section of the rotating shaft for centrifugal phase separation. The light phase and heavy phase after phase separation continuously flow out of the rotating microreactor through the light phase outlet and the heavy phase outlet, respectively.

[0095] After the rotary microreactor was continuously operated for 30 min, the raffinate phase was taken and the mass fraction of P2O5 therein was determined according to the method of GB / T 23843-2009, and the extraction rate was calculated according to the method in Example 6. w The results show that the extraction rate of phosphoric acid in this embodiment is 64.1%.

[0096] Example 10 In this embodiment, phosphoric acid extraction is taken as an example to illustrate the liquid-liquid extraction method of the present invention.

[0097] A mixture of tributyl phosphate and kerosene was used as the extractant, with a volume ratio of tributyl phosphate to kerosene of 8:2. A phosphoric acid aqueous solution with a P2O5 mass content of 46% was used as the feed liquid to be extracted. The rotary microreactor described in Example 5 was used. The extractant was placed in an extractant storage tank 19, which was connected to one inlet of a T-type mixed feed port via a pipe fitting via a first delivery pump 20. The feed liquid to be extracted was placed in a feed liquid storage tank 21, which was connected to the other inlet of the T-type mixed feed port via a pipe fitting via a second delivery pump 22. The steps were as follows: ① Start the driving device of the rotating microreactor to drive the rotating shaft to drive the rotating disc and the separation cylinder to rotate around the axis of the rotating shaft at a speed of 500 rpm.

[0098] ② The extractant and the liquid to be extracted are continuously introduced into the lower shell through the T-shaped mixing feed port by the first delivery pump and the second delivery pump respectively, and the volume flow rate of the extractant is controlled to be 60 m 3 / h, and the volume flow rate of the liquid to be extracted is controlled to be 12 m 3 / h, the extractant and the feed liquid undergo liquid-liquid extraction reaction in the lower shell, and then are continuously passed into the separation cylinder through the material conveying section of the rotating shaft for centrifugal phase separation. The light phase and heavy phase after phase separation continuously flow out of the rotating microreactor through the light phase outlet and the heavy phase outlet respectively.

[0099] After the rotary microreactor was continuously operated for 30 min, the raffinate phase was taken and the mass fraction of P2O5 therein was determined according to the method of GB / T 23843-2009, and the extraction rate was calculated according to the method in Example 6. w The results show that the extraction rate of phosphoric acid in this embodiment is 63.5%.

[0100] As shown in Examples 6-10, the extraction rates of phosphoric acid in Examples 6-10 are substantially comparable. This demonstrates that scaling up the rotary microreactor of the present invention for the same liquid-liquid extraction reaction does not significantly adversely affect the extraction rate. This demonstrates that the rotary microreactor provided by the present invention is easily scalable for industrial use.

Claims

1. A rotating microreactor, comprising a driving device (1), a rotating shaft (2), and a housing, characterized in that: It also includes a rotating disc (4), a fixed ring (5) and a centrifugal phase separation structure, and the shell includes a lower shell (3) and an upper shell (8); The rotating shaft (2) is composed of a rotating disc mounting section (201) and a material conveying section (202) connected to each other, and the material conveying section (202) is provided with a liquid inlet (203) and an open end; the lower shell (3) is a cylindrical body with closed ends, and the lower shell (3) is provided with a mixing feed inlet (6), a rotating shaft inlet, and a rotating shaft outlet; there are N rotating discs (4) and N-1 fixed rings (5), where N is an integer ≥ 2; each rotating disc (4) is horizontally arranged on the rotating disc mounting section (201), and each fixed ring (5) is horizontally arranged on the inner side wall of the lower shell (3); The centrifugal phase separation structure is located above the lower shell (3), and comprises a separation cylinder (7) and an upper shell (8) which is covered outside the separation cylinder (7). A separation cylinder feed port is provided at the center of the bottom of the separation cylinder (7); the lower end of the rotating shaft (2) is connected to the driving device (1) located below the lower shell (3), the upper end of the rotating shaft (2) is communicated with the separation cylinder feed port, and the rotating disc mounting section (201) and the liquid inlet (203) are located in the lower shell (3); each rotating disc (4) and each fixed ring (5) are arranged alternately; the axis of the lower shell (3) is perpendicular to the horizontal plane, and the axes of the rotating disc (4), the fixed ring (5), the rotating shaft (2) and the separation cylinder (7) all coincide with the axis of the lower shell (3); there are gaps between the fixed ring (5) and the rotating shaft (2), between the rotating disc (4) and the inner side wall of the lower shell (3), and between adjacent rotating discs (4) and the fixed ring (5).

2. The rotary microreactor according to claim 1, characterized in that The separation cylinder (7) is a cylindrical body with both ends closed. A light phase outlet (9) is provided on the upper end surface of the separation cylinder (7), and a heavy phase outlet (10) is provided on the upper part of the side wall of the separation cylinder (7). The lower end of the upper shell (8) is fixed to the top of the lower shell (3), and a gap is provided between the inner wall of the upper shell (8) and the separation cylinder (7). The upper shell (8) is provided with a light phase weir (11), a heavy phase collecting weir (12) and a heavy phase collecting port (13). A first rotating seal (14) is provided between the upper part of the heavy phase outlet (10) and the inner side wall of the upper shell (8), and a second rotating seal (15) is provided between the lower part of the heavy phase outlet (10) and the heavy phase collecting weir (12). A third rotating seal (16) is provided at the gaps between the rotating shaft (2) and the rotating shaft inlet and the rotating shaft outlet of the lower shell (3).

3. The rotary microreactor according to claim 2, characterized in that The heavy phase collecting weir (12) is arranged on the inner side wall of the upper shell (8). The heavy phase collecting weir (12) is located below the heavy phase outlet (10) and is arranged around the separation cylinder (7).

4. The rotary microreactor according to claim 1, characterized in that A baffle (17) is provided in the separation cylinder (7), and the baffle (17) is located near the feed port of the separation cylinder.

5. The rotary microreactor according to any one of claims 1 to 4, characterized in that: The distance between the inner wall of the fixed ring (5) and the outer wall of the rotating shaft (2) is 5 to 100 mm, the distance between the side wall of the rotating disk (4) and the inner wall of the lower shell (3) is 5 to 100 mm, and the distance between adjacent rotating disks (4) and the fixed ring (5) in the axial direction of the rotating shaft (2) is 0.5 to 100 mm.

6. The rotary microreactor according to any one of claims 1 to 4, characterized in that: The distance between the fixed ring (5) and the adjacent rotating disk (4) located above it in the axial direction of the rotating shaft (2) is 0.4 to 1 times the distance between the fixed ring (5) and the adjacent rotating disk (4) located below it in the axial direction of the rotating shaft (2).

7. The rotary microreactor according to any one of claims 1 to 4, characterized in that: The thickness of the rotating disk (4) is 5 to 50 mm, the thickness of the fixed ring (5) is 5 to 50 mm, and the diameter of the rotating disk (4) is 4 to 150 cm.

8. The rotary microreactor according to any one of claims 1 to 4, characterized in that: N is an integer between 2 and 25.

9. The rotary microreactor according to any one of claims 1 to 4, characterized in that: The ratio of the inner diameter of the separation cylinder (7) to the diameter of the rotating disc (4) is (0.6-0.9):1, and the ratio of the height of the separation cylinder (7) to the diameter of the rotating disc (5) is (1-8):

1.

10. A liquid-liquid extraction method, characterized in that: Using the rotary microreactor according to any one of claims 1 to 9 comprises the following steps: ① Start the driving device (1) to drive the rotating shaft (2) to drive the rotating disc (4) and the separation cylinder (7) to rotate; ② The extractant and the liquid to be extracted are continuously introduced into the lower shell (3) through the mixing feed port (6), and the extractant and the liquid undergo a liquid-liquid extraction reaction in the lower shell (3). Thereafter, the extractant and the liquid are continuously introduced into the separation cylinder (7) through the material conveying section (202) of the rotating shaft (2) for centrifugal phase separation. After phase separation, the light phase and the heavy phase continuously flow out of the rotating microreactor through the light phase weir (11) and the heavy phase collection port (13), respectively.

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