A screening device and method for fischer-tropsch synthesis catalyst fines recycling
By integrating a screening device that combines vibrating screening, cyclone separation, and electromagnetic adsorption, the problem of separating fine powder from Fischer-Tropsch synthesis catalysts has been solved, enabling efficient recovery and resource utilization, and improving the stability and production efficiency of the catalysts.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHINA ENERGY INVESTMENT CORP LTD
- Filing Date
- 2024-12-05
- Publication Date
- 2026-06-05
AI Technical Summary
Existing technologies struggle to efficiently separate and recover fine powder from Fe-Tropsch synthesis catalysts, leading to resource waste and increased production costs. Furthermore, the fine powder can easily cause reactor clogging and filter performance degradation.
A screening device integrating vibrating sieving, cyclone separation and electromagnetic adsorption is adopted. By using a partitioned vibrating screen and an electromagnetic adsorber, the fine powder separation efficiency is improved, and the fine powder is mixed with potassium-rich ceramic powder to prepare a regenerated catalyst.
This method enables the efficient recovery and resource utilization of Fischer-Tropsch synthesis catalyst fine powder, improves separation efficiency, reduces production costs, and enhances catalyst stability.
Smart Images
Figure CN122141958A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of Fischer-Tropsch synthesis, specifically to a screening device and method for the recovery and utilization of fine powder from Fischer-Tropsch synthesis catalysts. Background Technology
[0002] In the industrial production of Fischer-Tropsch synthesis catalysts, a portion of fine catalyst powder with a particle size of less than 40 μm is produced, accounting for approximately 10-30% of the total catalyst volume. This portion of fine catalyst powder has the same properties as the finished commercial catalyst, but presents the following problems: In slurry bed reactors, catalyst abrasion is severe, and the liquid products contain a considerable proportion of fine catalyst powder or dust, resulting in an increased fine powder content in the slurry. The fine powder particles are too small, making them more prone to pulverization and clogging the reactor. The large amount of fine powder leads to a significant decrease in filter performance and a reduction in production capacity.
[0003] General-purpose dust collection equipment has poor collection efficiency, making it difficult to completely separate fine catalyst powder beforehand. Some continuous fine powder classification technologies are time-consuming, resulting in significant loss of coarse particles during the classification process. The difficulty in separating fine powder or dust from liquid products increases the complexity and operating costs of Fischer-Tropsch synthesis industrialization, and negatively impacts product quality.
[0004] Because the particle size of catalyst powder is too small, there is no mature resource utilization pathway, so it is usually treated as solid waste, resulting in resource waste and economic losses. Summary of the Invention
[0005] The purpose of this disclosure is to provide a screening device and method for the recovery and utilization of fine Fischer-Tropsch synthesis catalyst powder. The screening device of this disclosure integrates the functions of vibrating screening, cyclone separation and electromagnetic adsorption, which can improve the efficiency and effect of Fischer-Tropsch synthesis catalyst powder recovery and utilization. The method of this disclosure can effectively realize the resource utilization of catalyst powder.
[0006] To achieve the above objectives, the first aspect of this disclosure provides a sieving device for recovering fine powder of Fehling-Tropsch synthesis catalyst, the sieving device comprising a shell, a vibrating screen, a screen support frame, a vibrator, and an electromagnetic adsorber; The screen support frame is disposed inside the housing, the circumferential direction of the vibrating screen is connected to the screen support frame, the vibrator is connected to the screen support frame to make the vibrating screen vibrate up and down; an air inlet is provided on the side wall of the housing above the upper surface of the vibrating screen; the electromagnetic adsorber is used to adsorb the catalyst fine powder on the side wall. The vibrating screen includes a first screening section and a second screening section arranged concentrically, with the second screening section located on the outer ring of the first screening section; the diameter of the inner hole of the first screening section is larger than the diameter of the inner hole of the second screening section, and the angle α between the plane of the screen surface of the second screening section and the screen surface of the first screening section is 5-60°.
[0007] Optionally, the screen of the first screening section is 100-400 mesh; the screen of the second screening section is 120-460 mesh.
[0008] Optionally, the vibrating screen is circular in shape, and the ratio of the radius of the vibrating screen to the radius of the first screening section is 1:(0.5-0.9).
[0009] Optionally, the screening device includes a plurality of vibrating screens, which are spaced apart along the axial direction of the screen support frame, and air inlets are provided on the side walls between adjacent vibrating screens.
[0010] Optionally, the angle β between the straight line of the air inlet opening and the side wall of the housing is 10-60°.
[0011] Optionally, the electromagnetic accelerator is disposed outside the housing and above the vibrating screen; the electromagnetic accelerator includes an electromagnet or an electromagnetic chuck.
[0012] A second aspect of this disclosure provides a method for recovering and reusing fine powder of a Fischer-Tropsch synthesis catalyst, the method comprising: S1. The Fischer-Tropsch synthesis catalyst to be treated is placed in the sieving device provided in the first aspect of this disclosure for sieving, purging and electromagnetic adsorption treatment to obtain fine catalyst powder; S2. The catalyst powder is mixed with potassium-rich ceramic powder and then shaped to obtain a regenerated Fischer-Tropsch synthesis catalyst.
[0013] Optionally, in step S1, the amplitude of the screening device is 0.2-3 mm, the vibration frequency is 600-3000 times / min, and the vibration time is 30-90 s; the flow rate of the purging gas is 100-1000 mL / min, and the purging time is 5-30 s; the electromagnetic adsorption time is 2-10 s, the interval between two electromagnetic adsorptions is 5-10 s, and the intensity of the electromagnetic field is 50-500 Gs. Preferably, the amplitude of the screening device is 0.5-2.5 mm, the vibration frequency is 800-2000 times / min, and the vibration time is 40-90 s; the flow rate of the purging gas is 150-450 mL / min, and the purging time is 10-30 s; the electromagnetic adsorption time is 2-8 s, the interval between two electromagnetic adsorptions is 5-8 s, and the intensity of the electromagnetic field is 50-300 Gs.
[0014] Optionally, in step S2, the volume ratio of the catalyst fine powder to the potassium-rich ceramic powder is 1:(0.05-1). Based on the dry weight of the potassium-rich ceramic powder, the potassium content in the potassium-rich ceramic powder is 5-15% by weight.
[0015] Optionally, in step S2, the molding process includes: pressing, crushing and sieving the mixture of the catalyst fine powder and the potassium-rich ceramic powder to select catalyst particles with a particle size of 50-150µm to obtain the regenerated Fischer-Tropsch synthesis catalyst.
[0016] Through the above technical solution, the screening device of this disclosure integrates the functions of vibrating screening, cyclone separation, and electromagnetic adsorption, effectively improving the recovery efficiency of Fischer-Tropsch synthesis catalyst fine powder, and further enhancing the fine powder separation effect by setting up a zoned vibrating screen. The method of this disclosure prepares a catalyst by mixing the separated Fischer-Tropsch synthesis catalyst fine powder with potassium-rich ceramic powder. The prepared catalyst is stable when used in the Fischer-Tropsch synthesis reaction, enabling the resource utilization of the catalyst fine powder.
[0017] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description
[0018] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of a specific embodiment of the screening device disclosed herein.
[0019] Figure 2 This is a top view of one specific embodiment of the screening device disclosed herein.
[0020] Explanation of reference numerals in the attached figures 1. Shell 2. Vibrating screen 3. Screen support frame 4. Electromagnetic adsorber; 5. Air inlet; 21. First screening section. 22. Second screening partition Detailed Implementation The specific embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.
[0021] In this disclosure, unless otherwise stated, directional terms such as "up," "down," "left," and "right" generally refer to "up," "down," "left," and "right" when the device of this disclosure is in normal working order.
[0022] like Figure 1 As shown, the first aspect of this disclosure provides a sieving device for recovering fine powder of Fe-Tropsch synthesis catalyst. The sieving device includes a housing 1, a vibrating screen 2, a screen support frame 3, a vibrator, and an electromagnetic adsorber 4. The screen support frame 3 is disposed inside the housing 1. The vibrating screen 2 is circumferentially connected to the screen support frame 3. The vibrator is connected to the screen support frame 3 to cause the vibrating screen 2 to vibrate up and down. An air inlet 5 is provided on the side wall of the housing above the upper surface of the vibrating screen 2. The electromagnetic adsorber is used to adsorb the fine catalyst powder onto the side wall. The vibrating screen includes a first sieving section 21 and a second sieving section 22 arranged concentrically. The second sieving section is located on the outer ring of the first sieving section. The aperture of the inner hole of the first sieving section 21 is larger than the aperture of the inner hole of the second sieving section 22. The angle α between the plane of the screen surface of the second sieving section 22 and the screen surface of the first sieving section 21 is 5-60°.
[0023] The screening device disclosed herein has a simple structure and integrates multiple functions such as vibrating screening, cyclone separation, and electromagnetic adsorption. In particular, by setting up a partitioned vibrating screen, the inclined surface of the second screening partition increases the collision probability between coarse Fischer-Tropsch synthesis catalyst particles during the rolling process. Furthermore, the smaller mesh aperture in this region prevents coarse Fischer-Tropsch synthesis catalyst particles from becoming embedded in the screen mesh. Simultaneously, during the rolling process of the coarse Fischer-Tropsch synthesis catalyst particles, the fine catalyst powder adhering to them detaches from the coarse particles and passes directly through the mesh of the second screening partition, thereby further separating the fine powder adhering to the coarse particles. The screening device disclosed herein exhibits high fine powder recovery efficiency and superior fine powder separation effect.
[0024] According to this disclosure, the vibrating screen is a screen with partitioned sections. For example, when the vibrating screen is circular, such as... Figure 2 As shown, the vibrating screen includes a central circular screen with a larger aperture and an outer annular screen with a smaller aperture. In one specific embodiment of this disclosure, the angle α between the plane containing the screen surface of the second screening section and the screen surface of the first screening section is 20-60°.
[0025] According to this disclosure, the mesh size of the first and second screening sections of the vibrating screen can vary within a wide range. In one specific embodiment of this disclosure, the mesh size of the first screening section 21 is 100-400 mesh; the mesh size of the second screening section 22 is 120-460 mesh. In this embodiment, the separation and recovery efficiency of the Fischer-Tropsch synthesis catalyst fine powder can be further improved.
[0026] In one specific embodiment of this disclosure, the vibrating screen is circular in shape, and the ratio of the radius of the vibrating screen to the radius of the first screening section can vary within a large range, for example, it can be 1:(0.5-0.9), preferably 1:(0.55-0.85).
[0027] In one specific embodiment of this disclosure, the screening device may include a plurality of vibrating screens 2, which are spaced apart along the axial direction of the screen support 3. Air inlets are provided on the sidewalls between adjacent vibrating screens. The number of vibrating screens can be selected according to actual needs, for example, 2-4. Multiple air inlets can be provided on the sidewalls between adjacent vibrating screens to more effectively form a gas vortex with the blown gas, further causing the fine powder adhering to the coarse particles of the Fischer-Tropsch synthesis catalyst to be swirled to the top of each screen layer and onto the sidewall of the shell, thereby further improving the recovery and separation effect of the catalyst fine powder. In one embodiment, the plurality of vibrating screens are arranged sequentially from top to bottom in order of decreasing aperture size in the first screening section. The ratio of the radius of each vibrating screen to the radius of the first screening section, and the angle α between the plane of the screen surface of the second screening section and the screen surface of the first screening section, can be the same or different, and can be set according to actual needs; this disclosure does not specifically limit this.
[0028] According to this disclosure, in order to form a cyclone within the screening device to detach the adhering catalyst powder and blow it onto the side wall of the housing, the opening direction of the air inlet can be towards the vibrating screen. In one specific embodiment of this disclosure, the angle β between the straight line containing the opening of the air inlet 5 and the side wall of the housing is 10-60°, to further improve the recovery effect of the catalyst powder.
[0029] According to this disclosure, electromagnetic adsorbers are well known to those skilled in the art. In one specific embodiment of this disclosure, the electromagnetic adsorber is disposed outside the housing and above the vibrating screen 2; the electromagnetic adsorber includes an electromagnet or an electromagnetic chuck. In this embodiment, the electromagnetic adsorber can increase the probability of catalyst fine powder being adsorbed onto the side wall of the housing, thereby further enhancing the separation of catalyst fine powder.
[0030] According to this disclosure, the vibrator is well known to those skilled in the art, as long as it can drive the screen support frame to vibrate, such as a vibrating motor.
[0031] The second aspect of this disclosure provides a method for recycling and reusing fine Fischer-Tropsch synthesis catalyst powder. The method includes: S1, placing the Fischer-Tropsch synthesis catalyst to be treated in a screening device provided in the first aspect of this disclosure for screening, purging and electromagnetic adsorption treatment to obtain fine catalyst powder; S2, mixing the fine catalyst powder with potassium-rich ceramic powder and performing molding treatment to obtain regenerated Fischer-Tropsch synthesis catalyst.
[0032] The method disclosed herein enables the efficient recovery of fine Fischer-Tropsch synthesis catalyst powder, and simultaneously mixes it with potassium-rich ceramic powder to prepare a regenerated Fischer-Tropsch synthesis catalyst. The prepared regenerated Fischer-Tropsch synthesis catalyst exhibits good catalytic stability, thus realizing the resource-based recovery and utilization of the Fischer-Tropsch synthesis catalyst.
[0033] In one specific embodiment of this disclosure, the sieving, purging, and electromagnetic adsorption treatment includes: SS1, vibrating a vibrating screen to vibrate and sieve the Fischer-Tropsch synthesis catalyst to be treated; SS2, after the vibrating sieving is completed, blowing gas into the Fischer-Tropsch synthesis catalyst to be treated through an air inlet to purge it; SS3, after the purging is completed, activating an electromagnetic adsorber to perform electromagnetic adsorption treatment on the Fischer-Tropsch synthesis catalyst to be treated; SS4, repeating steps SS1 to SS3.
[0034] In another specific embodiment of this disclosure, the sieving, purging and electromagnetic adsorption treatment includes: SS1, vibrating the vibrating screen to vibrate and sieve the Fischer-Tropsch synthesis catalyst to be treated; SS2, after the vibrating sieving is completed, blowing gas through the air inlet and simultaneously turning on the electromagnetic adsorber to purge and electromagnetically adsorb the Fischer-Tropsch synthesis catalyst to be treated; SS3, repeating steps SS1 to SS2.
[0035] According to this disclosure, the purging gas can be air and / or an inert gas, and this disclosure does not specifically limit it.
[0036] In one specific embodiment of this disclosure, in step S1, the amplitude of the sieving device is 0.2-3 mm, the vibration frequency is 600-3000 times / min, and the vibration time is 30-90 s; the flow rate of the purging gas is 100-1000 mL / min, and the purging time is 5-30 s; the electromagnetic adsorption treatment time is 2-10 s, the interval between two electromagnetic adsorptions is 5-10 s, and the electromagnetic field strength is 50-500 Gs. Preferably, the amplitude of the sieving device is 0.5-2.5 mm, the vibration frequency is 800-2000 times / min, and the vibration time is 40-90 s; the flow rate of the purging gas is 150-450 mL / min, and the purging time is 10-30 s; the electromagnetic adsorption time is 2-8 s, the interval between two electromagnetic adsorptions is 5-8 s, and the electromagnetic field strength is 50-300 Gs.
[0037] According to this disclosure, the volume ratio of the catalyst fine powder to the potassium-rich ceramic powder can vary within a wide range. In one specific embodiment of this disclosure, in step S2, the volume ratio of the catalyst fine powder to the potassium-rich ceramic powder is 1:(0.05-1). The potassium content in the potassium-rich ceramic powder can also vary within a wide range. In one embodiment, based on the dry weight of the potassium-rich ceramic powder, the potassium content in the potassium-rich ceramic powder is 5-15% by weight.
[0038] In one specific embodiment of this disclosure, step S2, the molding process includes: pressing, crushing, and sieving the mixture of the catalyst fine powder and the potassium-rich ceramic powder to select catalyst particles with a particle size of 50-150 µm, thereby obtaining the regenerated Fischer-Tropsch synthesis catalyst. In a preferred embodiment, the catalyst particles with a particle size less than 50 µm are further pressed, crushed, and sieved. The pressing, crushing, and sieving in this disclosure can employ methods well-known to those skilled in the art, and will not be described in detail here.
[0039] The regenerated Fischer-Tropsch synthesis catalyst obtained by the method disclosed herein can be used for Fischer-Tropsch synthesis reaction in a fixed-bed reactor. In one specific embodiment of this disclosure, hollow glass microspheres and the regenerated Fischer-Tropsch synthesis catalyst are mixed and then loaded into a fixed-bed reactor in stages.
[0040] The present disclosure will be further illustrated by the following examples, but the present disclosure is not limited thereto.
[0041] Unless otherwise specified, all raw materials used in the following examples and comparative examples were commercially available.
[0042] Example 1 The structure of the screening device in this embodiment is as follows: Figure 1As shown, the screening device includes a shell, four circular vibrating screens, a screen support frame, a vibrator, and an electromagnetic adsorber. The screen support frame is located inside the shell, and the circumferential direction of the vibrating screens is connected to the screen support frame. The vibrator is connected to the screen support frame to make the vibrating screens vibrate up and down. An air inlet is provided on the side wall of the shell above the upper surface of the vibrating screens. The electromagnetic adsorber is an electromagnet, located outside the shell and above the vibrating screens. Multiple vibrating screens are spaced apart along the axial direction of the screen support frame. An air inlet is provided on the side wall between adjacent vibrating screens, and the angle β between the line of the air inlet opening and the side wall of the shell is 45°.
[0043] The vibrating screen includes a first screening section and a second screening section arranged concentrically. The aperture of the inner hole in the first screening section is larger than that in the second screening section. The angle α between the plane containing the screen surface of the second screening section and the screen surface of the first screening section is 30°. The ratio of the radius of the vibrating screen to the radius of the first screening section is 1:0.75. The screen meshes in the first screening section of the four vibrating screens arranged from top to bottom along the shell are 400 mesh, 200 mesh, 140 mesh, and 100 mesh, respectively; the screen meshes in the second screening section are 460 mesh, 230 mesh, 170 mesh, and 120 mesh, respectively.
[0044] The above-mentioned vibrating sieving device is used for the recovery and utilization of fine powder from Fischer-Tropsch synthesis catalysts. S1. The Fischer-Tropsch synthesis catalyst to be treated is placed in the above-mentioned sieving device for sieving, purging and electromagnetic adsorption treatment, specifically as follows: -SS1. Set up a vibrating sieve device with an amplitude of 2mm, a vibration frequency of 1800 times / min, and a vibration time of 60s to vibrate the Fischer-Tropsch synthesis catalyst to be treated and sieve it. -SS2. When the vibrating screen stops, air is blown in through the air inlet to purge the Fischer-Tropsch synthesis catalyst to be treated. The gas flow rate is 200 mL / min to form a gas swirl. The purging is stopped after 20 seconds. -SS3. After stopping the purging for 5 seconds, turn on the electromagnetic adsorber to intermittently perform electromagnetic adsorption on the Fischer-Tropsch synthesis catalyst to be treated for 3 seconds. The strength of the electromagnetic field is 150 Gs, and the interval between the two electromagnetic adsorptions is 6 seconds. -SS4. After turning off the electromagnetic adsorber for 8 seconds, repeat steps SS1 to SS3 3 times.
[0045] S2. The catalyst fine powder with a particle size of less than 40 μm collected above is mixed with potassium-rich ceramic powder (potassium content of 10% by weight) at a volume ratio of 1:0.25. After mixing, the mixture is pressed into dense thin sheets. The sheets are then crushed and sieved, and catalyst particles with a particle size of 50-150 µm are selected as the regenerated Fischer-Tropsch synthesis catalyst. The fine powder <50 μm is re-pressed.
[0046] In this example, the recovery rate of catalyst fine powder with a particle size of less than 40 μm was 95%.
[0047] Example 2 The sieving device and method of Example 1 were used to recover the Fischer-Tropsch synthesis catalyst fine powder, with the only difference being that in step S1, the amplitude of the vibrating sieving device was 0.5 mm, the vibration frequency was 1000 times / min, and the vibration time was 40 s; the purging gas flow rate was 150 mL / min, and the purging time was 10 s; the electromagnetic adsorption time was 2 s, the electromagnetic field strength was 100 Gs, and the interval between two electromagnetic adsorptions was 8 s. In step S2, catalyst fine powder with a particle size of less than 40 μm was mixed with potassium-rich ceramic powder (potassium content of 5% by weight) at a volume ratio of 1:0.1.
[0048] In this example, the recovery rate of catalyst fine powder with a particle size of less than 40 μm was 91.5%.
[0049] Example 3 The apparatus and method of Example 1 were used to recover the Fischer-Tropsch synthesis catalyst fine powder, except that in step S2, the catalyst fine powder with a particle size of less than 40 μm was mixed with potassium-rich ceramic powder (potassium content of 8% by weight) at a volume ratio of 1:0.15.
[0050] In this example, the recovery rate of catalyst fine powder with a particle size of less than 40 μm was 95%.
[0051] Example 4 The apparatus and method of Example 1 were used to recover Fischer-Tropsch synthesis catalyst fine powder, with the only difference being that the angle α between the plane of the screen surface of the second sieve section and the screen surface of the first sieve section in the vibrating screen of the Fischer-Tropsch synthesis catalyst fine powder recovery apparatus was 10°; the ratio of the radius of the vibrating screen to the radius of the first sieve section was 1:0.9; and the angle β between the straight line of the air inlet opening and the side wall of the shell was 30°. In step S2, catalyst fine powder with a particle size of less than 40 μm was mixed with potassium-rich ceramic powder (potassium content of 5% by weight) at a volume ratio of 1:0.05.
[0052] In this example, the recovery rate of catalyst fine powder with a particle size of less than 40 μm was 82%.
[0053] Comparative Example 1 The Fischer-Tropsch synthesis catalyst to be treated was placed in a conventional vibrating screen device for sieving. Specifically, a vibrating screen device was set with an amplitude of 2 mm, a vibration frequency of 1500 times / min, and a vibration time of 60 s. Two conventional vibrating screens were set from top to bottom, with mesh sizes of 400 mesh and 100 mesh respectively. The vibrating screens were vibrated to sieve the Fischer-Tropsch synthesis catalyst to be treated.
[0054] In this comparative example, the recovery rate of catalyst fine powder with a particle size of less than 40 μm was 39%.
[0055] Test case Hollow glass microspheres with a particle size of 50-200 μm were selected and mixed with the regenerated Fischer-Tropsch synthesis catalyst particles prepared in the examples or the catalyst fine powder recovered in the comparative proportion. The mixture was then loaded into a fixed-bed reactor in stages according to the catalyst gradation method in Table 1. The Fischer-Tropsch synthesis reaction was carried out at 260 °C and 3 MPa for 100 h with a CO to H2 molar ratio of 1:2. The test results are shown in Table 2.
[0056] Table 1
[0057] Table 2
[0058] As can be seen from the above, the screening device disclosed herein can effectively recover and reuse the fine powder of Fischer-Tropsch synthesis catalyst. The regenerated Fischer-Tropsch synthesis catalyst prepared by mixing the recovered fine powder of Fischer-Tropsch synthesis catalyst with potassium-rich ceramic powder still has good catalytic stability.
[0059] The preferred embodiments of this disclosure have been described in detail above with reference to the accompanying drawings. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.
[0060] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.
[0061] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.
Claims
1. A sieving device for recovering fine powder of Fe-Tropsch synthesis catalyst, characterized in that, The screening device includes a housing (1), a vibrating screen (2), a screen support frame (3), a vibrator, and an electromagnetic adsorber (4). The screen support frame (3) is disposed inside the housing (1), the circumferential direction of the vibrating screen (2) is connected to the screen support frame (3), the vibrator is connected to the screen support frame (3) to make the vibrating screen (2) vibrate up and down; an air inlet (5) is provided on the side wall of the housing above the upper surface of the vibrating screen (2); the electromagnetic adsorber is used to adsorb the catalyst fine powder on the side wall; The vibrating screen includes a first screening section (21) and a second screening section (22) arranged concentrically. The second screening section is located on the outer ring of the first screening section. The diameter of the inner hole of the first screening section (21) is larger than the diameter of the inner hole of the second screening section (22). The angle α between the plane of the screen surface of the second screening section (22) and the screen surface of the first screening section (21) is 5-60°.
2. The screening device according to claim 1, wherein, The sieve of the first screening section (21) is 100-400 mesh; the sieve of the second screening section (22) is 120-460 mesh.
3. The screening device according to claim 1, wherein, The vibrating screen is circular in shape, and the ratio of the radius of the vibrating screen to the radius of the first screening section is 1:(0.5-0.9).
4. The screening device according to claim 1, wherein, The screening device includes a plurality of vibrating screens (2), which are spaced apart along the axial direction of the screen support frame (3), and air inlets are provided on the side walls between adjacent vibrating screens.
5. The screening device according to claim 1 or 4, wherein, The angle β between the straight line where the air inlet (5) is located and the side wall of the housing is 10-60°.
6. The screening device according to claim 1, wherein, The electromagnetic accelerator is located outside the housing and above the vibrating screen (2); the electromagnetic accelerator includes an electromagnet or an electromagnetic chuck.
7. A method for recovering and reusing fine powder of Fischer-Tropsch synthesis catalyst, characterized in that, The method includes: S1. The Fischer-Tropsch synthesis catalyst to be treated is placed in the sieving device described in any one of claims 1-6 for sieving, purging and electromagnetic adsorption treatment to obtain fine catalyst powder; S2. The catalyst powder is mixed with potassium-rich ceramic powder and then shaped to obtain a regenerated Fischer-Tropsch synthesis catalyst.
8. The method according to claim 7, wherein, In step S1, the amplitude of the screening device is 0.2-3 mm, the vibration frequency is 600-3000 times / min, and the vibration time is 30-90 s; The purging gas flow rate is 100-1000 mL / min, and the purging time is 5-30 s; The electromagnetic adsorption time is 2-10s, the interval between two electromagnetic adsorptions is 5-10s, and the intensity of the electromagnetic field is 50-500Gs. Preferably, the amplitude of the screening device is 0.5-2.5 mm, the vibration frequency is 800-2000 times / min, and the vibration time is 40-90 s; The purging gas flow rate is 150-450 mL / min, and the purging time is 10-30 s; The electromagnetic adsorption time is 2-8s, the interval between two electromagnetic adsorptions is 5-8s, and the intensity of the electromagnetic field is 50-300Gs.
9. The method according to claim 7, wherein, In step S2, the volume ratio of the catalyst fine powder to the potassium-rich ceramic powder is 1:(0.05-1). Based on the dry weight of the potassium-rich ceramic powder, the potassium content in the potassium-rich ceramic powder is 5-15% by weight.
10. The method according to claim 7, wherein, In step S2, the molding process includes: pressing, crushing and sieving the mixture of the catalyst fine powder and the potassium-rich ceramic powder to select catalyst particles with a particle size of 50-150µm to obtain the regenerated Fischer-Tropsch synthesis catalyst.