An alkyl lithium filtration process

Abstract

This invention belongs to the field of lithium industry technology, and particularly relates to an alkyl lithium filtration process, comprising the following steps: Step 1: Under the protection of argon gas, lithium metal particles and hydrocarbon solvent are added to a washing vessel, allowing the lithium metal particles to be washed to remove surface impurities; Step 2: Under the protection of argon gas, the washed lithium metal particles are added to a synthesis vessel, followed by the addition of hydrocarbon solvent, and the total solvent volume is adjusted to a specified value; Step 3: Chlorinated alkanes are added to the synthesis vessel using a mixed droplet method, and the chlorinated alkanes react fully with the lithium metal particles and hydrocarbon solvent in the reaction vessel at a specific temperature. When filtering the alkyl lithium solution, as the drive shaft rotates forward, the alkyl lithium solution sprayed through the through-holes on the drive shaft can be evenly sprayed onto the surface of the rotating sintered mesh filter element, thereby improving the filtration effect of the sintered mesh filter element on the alkyl lithium solution.

Description

Technical Field

[0001] This invention belongs to the field of lithium industry technology, and in particular relates to an alkyl lithium filtration process. Background Technology

[0002] Alkyl lithiums are alkyl derivatives of lithium, with the general formula RLi, where R is a straight-chain or branched alkyl, cycloalkyl, or aryl group, such as methyl lithium, ethyl lithium, propyl lithium, isopropyl lithium, n-butyl lithium, sec-butyl lithium, tert-butyl lithium, pentyl lithium, hexyl lithium, cyclohexyl lithium, tert-octyl lithium, n-eicosyl lithium, phenyl lithium, methylphenyl lithium, butylphenyl lithium, naphthyl lithium, and butylcyclohexyl lithium. They are commonly used as reagents, with n-butyl lithium solution being the most frequently used, primarily in the pharmaceutical field as a catalyst for organic synthesis.

[0003] The synthesis of alkyllithium mainly involves the reaction of chloroalkanes and lithium metal in a hydrocarbon solvent. After the synthesis is complete, the synthesized alkyllithium solution needs to be filtered to remove impurities and suspended solids. Existing filters generally use single-tube (sintered mesh or enamel filter element) or multi-tube vertical filters. However, because the sintered mesh filter element inside these filters cannot rotate, and the inlet position is relatively fixed, the alkyllithium solution entering the filter through the inlet cannot be uniformly filtered by the sintered mesh filter element, resulting in poor filtration efficiency for alkyllithium solutions.

[0004] Therefore, it is necessary to invent an alkyl lithium filtration process to solve the above problems. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides an alkyl lithium filtration process to solve the issues raised in the background section.

[0006] To achieve the above objectives, the present invention provides the following technical solution: an alkyl lithium filtration process, comprising the following steps:

[0007] Step 1: Under the protection of argon gas, add lithium metal particles and hydrocarbon solvent to the washing vessel, so that the impurities on the surface of the lithium metal particles are washed away by the action of the washing vessel.

[0008] Step 2: Under the protection of argon gas, the cleaned lithium metal particles are added to the synthesis reactor, followed by the addition of hydrocarbon solvents and adjustment of the total solvent volume to the specified value.

[0009] Step 3: Chlorinated alkanes are added to the synthesis vessel by a mixed dropwise addition method, and the chlorinated alkanes react fully with the lithium metal particles and hydrocarbon solvents in the reaction vessel at a specific temperature;

[0010] Step 4: After the reaction in Step 3 is completed, argon gas is introduced into the synthesis vessel, so that the reactants in the synthesis vessel are separated by the internal solid-liquid separator to intercept unreacted lithium particles and then enter the buffer tank.

[0011] Step 5: Argon gas is introduced into the buffer tank to force the material in the buffer tank into the filter for filtration, thereby obtaining a colorless or slightly yellow transparent alkyl lithium solution without suspended matter.

[0012] Furthermore, the filter in step five includes a filter tank, which is horizontally placed and has a sealing cap at one end. The filter tank contains a filtration zone and a drainage zone, with a vertical partition between them. The outer side of the partition is fixedly connected to the inner wall of the filter tank. Multiple positioning holes are perforated through the partition in a ring-shaped arrangement. An inlet pipe is inserted through the center of the partition on the side away from the filtration zone, with the end of the inlet pipe connected to the end of the filter tank away from the sealing cap. A fixing plate is vertically arranged within the filtration zone, fixedly connected to the inner wall of the filter tank on the outer side. Insertion holes are perforated on the fixing plate at positions opposite to the positioning holes. Multiple notches are evenly distributed along the edge of the fixing plate, and the insertion holes are used for rotatable installation. The device includes a retaining ring, which protrudes more than the retaining plate on the side near the sealing cover, and the surface of the protruding part of the retaining ring is evenly provided with teeth. A sintered mesh filter element is inserted through the retaining ring, and a liquid outlet pipe is inserted through the end of the sintered mesh filter element near the partition plate. The liquid outlet pipe is rotatably inserted through and into the corresponding positioning hole. A drive shaft is rotatably inserted through the center of the retaining plate. The two ends of the drive shaft are designed to be through-holes, and multiple strip-shaped through holes are symmetrically opened on the surfaces of the drive shaft on both sides of the retaining plate. The multiple strip-shaped through holes are distributed in a ring. The end of the drive shaft near the partition plate is rotatably connected to the center of the partition plate, and the interior of the drive shaft is connected to the liquid inlet pipe. A drive assembly is provided at the end of the drive shaft near the sealing cover, and cleaning assemblies are symmetrically provided on the parts of the drive shaft on both sides of the retaining plate.

[0013] Furthermore, the drive assembly includes a rotating shaft that is vertically rotatable and inserted through the center of the sealing cover. A motor is connected to the end of the rotating shaft away from the filter tank, and a square insert is fixedly connected to the other end of the rotating shaft. A connecting post is slidably fitted onto the insert, and the connecting post is rotatably installed inside the end of the drive shaft near the sealing cover. Multiple limiting blocks are uniformly fixedly connected to the surface of the connecting post, and these limiting blocks are arranged in a ring. Limiting holes are formed through the drive shaft at positions opposite to the limiting blocks, with the length of the limiting holes being greater than the length of the limiting blocks. The limiting blocks are slidably installed in the corresponding limiting holes. A gear is fitted onto the drive shaft, and the gear meshes with the teeth on multiple fixing rings.

[0014] Furthermore, the cleaning assembly includes multiple cleaning plates, which are correspondingly distributed between two adjacent sintered mesh filter elements. The cleaning plates have bristles evenly distributed on the side away from the drive shaft. Mounting rings are fixedly connected between the two ends of each cleaning plate, and these mounting rings are rotatably sleeved on the drive shaft. Each cleaning plate has a stop bar at both ends, which is perpendicularly fixed to the surface of the corresponding mounting ring. The length of the stop bar is greater than the width of the cleaning plate, and the stop bar is not located in the same plane as the corresponding cleaning plate. The bristles on the cleaning plate can contact one of the surfaces of two adjacent sintered mesh filter elements, and when the bristles contact the surface of that sintered mesh filter element, the stop bars at both ends of the corresponding cleaning plate also fit precisely against the surface of that sintered mesh filter element.

[0015] Furthermore, multiple deflection grooves are evenly provided on the inner wall of the fixing ring, and an arc-shaped spring is provided in the deflection groove. The two ends of the arc-shaped spring are always located in the deflection groove, and in the initial state, the middle part of the arc-shaped spring can be located outside the deflection groove.

[0016] Furthermore, a drain pipe is connected to one end of the filter tank near the inlet pipe, and the drain pipe is close to the bottom of the filter tank, and a sewage pipe is connected to the bottom of the filter tank.

[0017] Furthermore, a U-shaped handle is connected to one end of the sintered mesh filter element near the sealing cover. A pressure ring is installed on the sealing cover at the position opposite to the multiple handles, and when the sealing cover is closed, the pressure ring is able to fit close to the multiple handles.

[0018] Furthermore, a plurality of sealing strips are fixedly connected to the side of the connecting post away from the insert block. The sum of the lengths of the sealing strips and the connecting post is equivalent to the length of the drive shaft, and the plurality of sealing strips correspond one-to-one with the plurality of through holes. A support ring is fixedly connected to the end of the plurality of sealing strips away from the connecting post. The support ring is rotatably mounted on the inner side of the drive shaft. The plurality of sealing strips are all in contact with the inner wall of the drive shaft, and when the drive shaft rotates in the reverse direction, the plurality of sealing strips can simultaneously close the corresponding through holes.

[0019] Furthermore, the bottom of the filter tank is fixedly connected to two sets of support legs, and the two sets of support legs are symmetrically installed at the bottom of the filter tank.

[0020] The technical effects and advantages of this invention are as follows:

[0021] 1. When filtering alkyl lithium solution, as the drive shaft rotates in the forward direction, the alkyl lithium solution sprayed through the through hole on the drive shaft can be evenly sprayed onto the surface of the rotating sintered mesh filter element, thereby improving the filtration effect of the sintered mesh filter element on alkyl lithium solution.

[0022] 2. After the alkyl lithium solution has been filtered, the motor is started to drive the drive shaft to rotate in the opposite direction. This allows the cleaning plate to come into contact with the sintered mesh filter element in the direction of rotation under the friction of the drive shaft against the mounting ring. Then, cleaning agent is injected into the drainage area through the drainage pipe. As the cleaning agent is continuously injected, it can enter the interior of the sintered mesh filter element through the outlet pipe, thereby rinsing the sintered mesh filter element from the inside out. This, combined with the brushing operation on the surface of the sintered mesh filter element, improves the cleaning efficiency and effect of the sintered mesh filter element surface.

[0023] 3. After the alkyl lithium solution has completed the filtration process, start the motor to drive the shaft to rotate in the opposite direction. As the shaft rotates in the opposite direction, the connecting column can drive the sealing strip and the limiting block to rotate in the opposite direction as well. During this process, the limiting block can move along the limiting hole, while the sealing strip can move closer to the through hole on the corresponding side. When the limiting block reaches the maximum movement distance along the limiting hole, the sealing strip just closes the through hole on the corresponding side, thereby preventing impurities from entering the drive shaft through the through hole during the rinsing process. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0025] Figure 2 This is a schematic diagram of the internal three-dimensional structure of the filter tank in this invention;

[0026] Figure 3 In this invention Figure 2 Partial three-dimensional structural cross-sectional view;

[0027] Figure 4 This is a three-dimensional structural diagram of the fixing plate, fixing ring, and bow-shaped spring in this invention;

[0028] Figure 5 This is a three-dimensional structural diagram of the sealing cover, rotating shaft, insert block, pressure ring, and motor in this invention;

[0029] Figure 6 This is a three-dimensional schematic diagram of the cleaning components, drive shaft, and connecting column in this invention;

[0030] Figure 7 This is a three-dimensional structural diagram of the drive shaft and gear in this invention;

[0031] Figure 8 This is a three-dimensional structural diagram of the connecting column, limiting block, sealing strip, and support ring in this invention.

[0032] In the diagram: 1. Filter tank; 2. Sealing cover; 3. Partition plate; 4. Inlet pipe; 5. Fixing plate; 6. Fixing ring; 7. Sintered mesh filter element; 8. Outlet pipe; 9. Drive shaft; 10. Rotating shaft; 11. Motor; 12. Insert block; 13. Connecting column; 14. Limiting block; 15. Gear; 16. Cleaning plate; 17. Brush bristles; 18. Mounting ring; 19. Stop bar; 20. Bow-shaped spring; 21. Drain pipe; 22. Sewage pipe; 23. Handle; 24. Pressure ring; 25. Sealing strip; 26. Support ring; 27. Support leg. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments.

[0034] This invention provides, for example Figures 1 to 8 The alkyl lithium filtration process shown includes the following steps:

[0035] Step 1: Under the protection of argon gas, add lithium metal particles and hydrocarbon solvent to the washing vessel, so that the impurities on the surface of the lithium metal particles are washed away by the action of the washing vessel.

[0036] Step 2: Under the protection of argon gas, the cleaned lithium metal particles are added to the synthesis reactor, followed by the addition of hydrocarbon solvents and adjustment of the total solvent volume to the specified value.

[0037] Step 3: Chlorinated alkanes are added to the synthesis vessel by a mixed dropwise addition method, and the chlorinated alkanes react fully with the lithium metal particles and hydrocarbon solvents in the reaction vessel at a specific temperature;

[0038] Step 4: After the reaction in Step 3 is completed, argon gas is introduced into the synthesis vessel, so that the reactants in the synthesis vessel are separated by the internal solid-liquid separator to intercept unreacted lithium particles and then enter the buffer tank.

[0039] Step 5: Argon gas is introduced into the buffer tank to force the material in the buffer tank into the filter for filtration, thereby obtaining a colorless or slightly yellow transparent alkyl lithium solution without suspended matter.

[0040] like Figures 2 to 8As shown, the filter in step five includes a filter tank 1, which is placed horizontally and has a sealing cap 2 at one end. The filter tank 1 contains a filtration zone and a drainage zone, with a vertical partition 3 between them. The outer side of the partition 3 is fixedly connected to the inner wall of the filter tank 1. Multiple positioning holes are perforated on the partition 3 in a ring-shaped arrangement. An inlet pipe 4 is inserted through the center of the side of the partition 3 away from the filtration zone. The end of the inlet pipe 4 away from the partition 3 is inserted through the end of the filter tank 1 away from the sealing cap 2. A fixing plate 5 is vertically installed in the filtration zone, and its outer side is fixedly connected to the inner wall of the filter tank 1. Insertion holes are perforated on the fixing plate 5 at positions opposite to the positioning holes. Multiple notches are evenly distributed along the edge of the fixing plate 5. A fixing ring 6 is rotatably installed in the insertion holes. The side of the fixing ring 6 closest to the sealing cap 2 protrudes further than the fixing plate 5, and the surface of the protruding part of the fixing ring 6 is evenly provided with teeth. A perforated part of the fixing ring 6... A sintered mesh filter element 7 is connected to a liquid outlet pipe 8 through one end of the sintered mesh filter element 7 near the partition plate 3. The liquid outlet pipe 8 is rotatably inserted into the corresponding positioning hole. A drive shaft 9 is rotatably inserted into the center of the fixed plate 5. The two ends of the drive shaft 9 are designed to be through, and multiple strip-shaped through holes are symmetrically opened on the surfaces of the drive shaft 9 on both sides of the fixed plate 5. The multiple strip-shaped through holes are distributed in a ring. The end of the drive shaft 9 near the partition plate 3 is rotatably connected to the center of the partition plate 3, and the interior of the drive shaft 9 is connected to the liquid inlet pipe 4. A drive assembly is provided at the end of the drive shaft 9 near the sealing cover 2. A cleaning assembly is symmetrically provided on the part of the drive shaft 9 on both sides of the fixed plate 5. A drain pipe 21 is connected to the end of the filter tank 1 near the liquid inlet pipe 4, and the drain pipe 21 is close to the bottom of the filter tank 1. A sewage pipe 22 is connected to the bottom of the filter tank 1. Two sets of support legs 27 are fixedly connected to the bottom of the filter tank 1, and the two sets of support legs 27 are symmetrically installed at the bottom of the filter tank 1.

[0041] Before filtering the alkyl lithium solution, open the sealing cover 2 and insert multiple sintered mesh filter elements 7 one by one into the fixing rings 6 on the fixing plate 5. Then close the sealing cover 2 and start the drive assembly. Driven by the drive assembly, the drive shaft 9 drives the multiple fixing rings 6 and the sintered mesh filter elements 7 inside to rotate synchronously through the gear 15. After the speed of the drive shaft 9 stabilizes, the alkyl lithium solution is introduced into the drive shaft 9 through the liquid inlet pipe 4. The alkyl lithium solution that enters the drive shaft 9 can be evenly sprayed onto the surface of the sintered mesh filter element 7 through the through holes on the surface of the drive shaft 9, thereby improving the filtration effect of the sintered mesh filter element 7 on the alkyl lithium solution.

[0042] After filtration is complete, the drive assembly is activated, causing the drive shaft 9 to rotate in the opposite direction. Then, cleaning agent is injected into the drainage area through the drain pipe 21. As the cleaning agent is continuously injected, it enters the interior of the sintered mesh filter element 7 through the outlet pipe 8, thereby rinsing the sintered mesh filter element 7 from the inside out. This, combined with the brushing operation of the cleaning assembly on the surface of the sintered mesh filter element 7, improves the cleaning efficiency and effect. The impurities washed off are discharged from the drain pipe 22 along with the cleaning agent.

[0043] like Figures 2 to 8 As shown, the drive assembly includes a rotating shaft 10, which is vertically rotatably inserted into the center of the sealing cover 2. A motor 11 is connected to one end of the rotating shaft 10 away from the filter tank 1, and a square insert 12 is fixedly connected to the other end of the rotating shaft 10. A connecting post 13 is slidably sleeved on the insert 12. The connecting post 13 is rotatably installed inside the end of the drive shaft 9 near the sealing cover 2. Multiple limiting blocks 14 are uniformly fixedly connected to the surface of the connecting post 13, and the multiple limiting blocks 14 are arranged in a ring. A limiting hole is opened through the drive shaft 9 at the position opposite to the limiting block 14. The length of the limiting hole is greater than the length of the limiting block 14, and the limiting block 14 is slidably installed in the corresponding limiting hole. A gear 15 is sleeved on the drive shaft 9, and the gear 15 meshes with the teeth on multiple fixing rings 6.

[0044] The cleaning assembly includes multiple cleaning plates 16, which are distributed between two adjacent sintered mesh filter elements 7. Brushes 17 are evenly arranged on the side of the cleaning plate 16 away from the drive shaft 9. Mounting rings 18 are fixedly connected between the two ends of the multiple cleaning plates 16. The mounting rings 18 are rotatably sleeved on the drive shaft 9. A stop bar 19 is provided at both ends of the cleaning plate 16. The stop bar 19 is perpendicularly fixedly connected to the surface of the corresponding mounting ring 18. The length of the stop bar 19 is greater than the width of the cleaning plate 16, and the stop bar 19 is not located in the same plane as the corresponding cleaning plate 16. The brushes 17 on the cleaning plate 16 can contact one of the surfaces of two adjacent sintered mesh filter elements 7. When the brushes 17 contact the surface of the sintered mesh filter element 7, the stop bars 19 at both ends of the corresponding cleaning plate 16 are also in contact with the surface of the sintered mesh filter element 7.

[0045] When filtering the alkyl lithium solution, the motor 11 is started, causing the rotating shaft 10 to rotate. As the rotating shaft 10 rotates, it drives the connecting column 13 and the drive shaft 9 to rotate together via the insert block 12. As the drive shaft 9 rotates, it drives multiple fixed rings 6 and the sintered mesh filter element 7 inside them to rotate together via the gear 15. In addition, as the drive shaft 9 rotates in the forward direction, the mounting ring 18, the stop bar 19, and the cleaning plate 16 can first rub against the mounting ring 18 on the drive shaft 9. Driven by the force, it rotates together with the drive shaft 9. When the stop rod 19 contacts the surface of the sintered mesh filter element 7 in its rotation direction, the stop rod 19, due to the obstruction of the sintered mesh filter element 7, drives the mounting ring 18 and the cleaning plate 16 to remain relatively stationary with the filter tank 1. At this time, the cleaning plate 16 does not contact any surface of the sintered mesh filter element 7, thereby ensuring that the cleaning plate 16 and the bristles 17 will not affect the subsequent filtration operation of the sintered mesh filter element 7, while the mounting ring 18 maintains relative rotation with the drive shaft 9.

[0046] Once the drive shaft 9 reaches a stable speed, an alkyl lithium solution is introduced into the drive shaft 9 through the inlet pipe 4. The alkyl lithium solution entering the drive shaft 9 can be sprayed onto the surface of the sintered mesh filter element 7 through the through holes on the surface of the drive shaft 9. Since the sintered mesh filter element 7 is rotating, the alkyl lithium solution can be sprayed evenly onto the surface of the sintered mesh filter element 7, thereby enabling the entire sintered mesh filter element 7 to filter the alkyl lithium solution evenly, thus improving the filtration effect of the sintered mesh filter element 7 on the alkyl lithium solution. The filtered alkyl lithium solution can be discharged from the filter tank 1 through the drain pipe 21.

[0047] After the alkyl lithium solution is filtered, the motor 11 is started, which drives the drive shaft 9 to rotate in the opposite direction via the rotating shaft 10. Unlike the forward rotation of the drive shaft 9, the cleaning plate 16 can contact the sintered mesh filter element 7 in the direction of rotation of the drive shaft 9 under the friction of the mounting ring 18. The multiple sintered mesh filter elements 7 can still rotate under the drive of the gear 15. At this time, the bristles 17 on the cleaning plate 16 can brush the surface of the sintered mesh filter element 7. Then, the cleaning agent is injected into the drainage area through the drainage pipe 21. As the cleaning agent is continuously injected, it can enter the interior of the sintered mesh filter element 7 through the outlet pipe 8 of the sintered mesh filter element 7, thereby rinsing the sintered mesh filter element 7 from the inside out. This, combined with the brushing operation of the bristles 17 on the surface of the sintered mesh filter element 7, improves the cleaning efficiency and effect of the surface of the sintered mesh filter element 7. The impurities washed off can be discharged from the drain pipe 22 along with the cleaning agent.

[0048] like Figure 4As shown, multiple deflection grooves are evenly provided on the inner wall of the fixed ring 6. A bow-shaped spring piece 20 is provided in the deflection groove. Both ends of the bow-shaped spring piece 20 are always located in the deflection groove, and in the initial state, the middle part of the bow-shaped spring piece 20 can be located outside the deflection groove.

[0049] By providing bow-shaped springs 20, during the process of inserting the sintered mesh filter element 7 into the inner side of the fixing ring 6, as the sintered mesh filter element 7 is continuously inserted, when the sintered mesh filter element 7 comes into contact with the multiple bow-shaped springs 20 on the inner wall of the fixing ring 6, the bow-shaped springs 20 can deflect into the deflection groove under the squeezing action of the sintered mesh filter element 7. When the sintered mesh filter element 7 completes the insertion operation, the multiple bow-shaped springs 20 on the fixing ring 6 can remain in close contact with the outer wall of the sintered mesh filter element 7. Thus, when the fixing ring 6 rotates under the drive of the gear 15, it ensures that the sintered mesh filter element 7 inside the fixing ring 6 can rotate together with the fixing ring 6, avoiding free rotation between the fixing ring 6 and the sintered mesh filter element 7.

[0050] like Figure 2 As shown, a U-shaped handle 23 is connected to one end of the sintered mesh filter element 7 near the sealing cover 2. A pressure ring 24 is installed at the position opposite to the multiple handles 23 on the sealing cover 2. When the sealing cover 2 is closed, the pressure ring 24 can just be close to the multiple handles 23.

[0051] The handle 23 facilitates the installation and removal of the sintered mesh filter element 7. When the sealing cover 2 is closed, the pressure ring 24 can restrict the sintered mesh filter element 7 through the handle 23, thereby allowing the sintered mesh filter element 7 to rotate in a fixed position.

[0052] like Figures 6 to 8 As shown, a plurality of sealing strips 25 are fixedly connected to the side of the connecting post 13 away from the insert block 12. The sum of the lengths of the sealing strips 25 and the connecting post 13 is equivalent to the length of the drive shaft 9. The plurality of sealing strips 25 correspond one-to-one with the plurality of through holes. A support ring 26 is fixedly connected to the end of the plurality of sealing strips 25 away from the connecting post 13. The support ring 26 is rotatably mounted on the inner side of the drive shaft 9. The plurality of sealing strips 25 are all in contact with the inner wall of the drive shaft 9. When the drive shaft 9 rotates in the opposite direction, the plurality of sealing strips 25 can simultaneously close the corresponding through holes.

[0053] With the sealing strip 25 provided, when the rotating shaft 10 drives the drive shaft 9 to rotate in the forward direction, the sealing strip 25 can be offset from the through hole on the drive shaft 9. At this time, the alkyl lithium solution that enters the drive shaft 9 through the liquid inlet pipe 4 can be sprayed onto the surface of the sintered mesh filter element 7 through the through hole on the drive shaft 9. This allows the alkyl lithium solution to be discharged into the drainage area through the liquid outlet pipe 8 of the sintered mesh filter element 7 after being filtered by the sintered mesh filter element 7, and finally discharged from the filter tank 1 through the liquid outlet pipe 21.

[0054] After the alkyl lithium solution completes the filtration process, cleaning agent can be injected into the drainage area through the drain pipe 21. At the same time, the motor 11 is started, causing the rotating shaft 10 to rotate in the opposite direction. As the rotating shaft 10 rotates in the opposite direction, the connecting column 13 can drive the sealing strip 25 and the limiting block 14 to rotate in the opposite direction together. During this process, the limiting block 14 can move along the limiting hole, while the sealing strip 25 can move closer to the through hole on the corresponding side. When the limiting block 14 reaches the maximum movement distance along the limiting hole, the sealing strip 25 just closes the through hole on the corresponding side, thereby preventing impurities from entering the drive shaft 9 through the through hole during the rinsing process. As the limiting block 14 continues to move, the limiting block 14 can drive the drive shaft 9 to rotate in the opposite direction together with the rotating shaft 10 through the limiting hole.

[0055] As the cleaning agent is continuously injected, it can enter the interior of the sintered mesh filter element 7 through the liquid outlet pipe 8, thereby rinsing the sintered mesh filter element 7 from the inside out. The impurities washed off can be discharged from the drain pipe 22 along with the cleaning agent.

[0056] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it.

Claims

1. An alkyl lithium filtration process characterized by: Includes the following steps: Step 1: Under the protection of argon gas, add lithium metal particles and hydrocarbon solvent to the washing vessel, so that the impurities on the surface of the lithium metal particles are washed away by the action of the washing vessel. Step 2: Under the protection of argon gas, the cleaned lithium metal particles are added to the synthesis reactor, followed by the addition of hydrocarbon solvents and adjustment of the total solvent volume to the specified value. Step 3: Chlorinated alkanes are added to the synthesis vessel by a mixed dropwise addition method, and the chlorinated alkanes react fully with the lithium metal particles and hydrocarbon solvents in the reaction vessel at a specific temperature; Step 4: After the reaction in Step 3 is completed, argon gas is introduced into the synthesis vessel, so that the reactants in the synthesis vessel are separated by the internal solid-liquid separator to intercept unreacted lithium particles and then enter the buffer tank. Step 5: Argon gas is introduced into the buffer tank to force the material in the buffer tank into the filter for filtration, thereby obtaining a colorless or slightly yellow transparent alkyl lithium solution without suspended matter. The filter in step five includes a filter tank, which is horizontally placed and has a sealing cap at one end. The filter tank contains a filtration zone and a drainage zone, with a vertical partition between them. The outer side of the partition is fixedly connected to the inner wall of the filter tank. Multiple positioning holes are formed through the partition in a ring-shaped arrangement. An inlet pipe is inserted through the center of the partition on the side furthest from the filtration zone, with the end of the inlet pipe furthest from the partition connected to the end of the filter tank furthest from the sealing cap. A fixing plate is vertically positioned within the filtration zone, fixedly connected to the inner wall of the filter tank on the outer side. Insertion holes are formed through the fixing plate at positions opposite to the positioning holes. Multiple notches are evenly distributed along the edge of the fixing plate, and fixing parts are rotatably installed within these insertion holes. The ring has a fixed ring that protrudes more than the fixed plate on the side near the sealing cover, and the surface of the protruding part of the fixed ring is evenly provided with teeth. A sintered mesh filter element is inserted through the fixed ring. A liquid outlet pipe is inserted through the end of the sintered mesh filter element near the partition plate. The liquid outlet pipe is rotatably inserted through the corresponding positioning hole. A drive shaft is rotatably inserted through the center of the fixed plate. The two ends of the drive shaft are designed to be through-holes. Multiple strip-shaped through holes are symmetrically opened on the surface of the drive shaft on both sides of the fixed plate. The multiple strip-shaped through holes are distributed in a ring. The end of the drive shaft near the partition plate is rotatably connected to the center of the partition plate. The interior of the drive shaft is connected to the liquid inlet pipe. A drive assembly is provided at the end of the drive shaft near the sealing cover. Cleaning assemblies are symmetrically provided on the part of the drive shaft on both sides of the fixed plate. The drive assembly includes a rotating shaft that is vertically rotatable and inserted through the center of the sealing cover. A motor is connected to the end of the rotating shaft away from the filter tank, and a square insert is fixedly connected to the other end of the rotating shaft. A connecting post is slidably sleeved on the insert, and the connecting post is rotatably installed inside the end of the drive shaft near the sealing cover. Multiple limiting blocks are evenly fixedly connected to the surface of the connecting post, and the multiple limiting blocks are arranged in a ring. A limiting hole is opened through the drive shaft at the position opposite to the limiting block. The length of the limiting hole is greater than the length of the limiting block, and the limiting block is slidably installed in the corresponding limiting hole. A gear is sleeved on the drive shaft, and the gear meshes with the teeth on multiple fixed rings. Multiple sealing strips are fixedly connected to the side of the connecting post away from the insert block. The sum of the lengths of the sealing strips and the connecting post is equivalent to the length of the drive shaft. Each sealing strip corresponds to a different through hole. A support ring is fixedly connected to the end of each sealing strip away from the connecting post. The support ring is rotatably mounted on the inner side of the drive shaft. Each sealing strip is in contact with the inner wall of the drive shaft. When the drive shaft rotates in the opposite direction, the multiple sealing strips can simultaneously close the corresponding through holes.

2. The alkyl lithium filtration process of claim 1, wherein: The cleaning assembly includes multiple cleaning plates, which are distributed between two adjacent sintered mesh filter elements. The cleaning plates have bristles evenly distributed on the side away from the drive shaft. Mounting rings are fixedly connected to both ends of each cleaning plate, and these mounting rings are rotatably sleeved on the drive shaft. Each cleaning plate has a stop bar at both ends, which is perpendicularly fixed to the surface of the corresponding mounting ring. The length of the stop bar is greater than the width of the cleaning plate, and the stop bar is not located in the same plane as the corresponding cleaning plate. The bristles on the cleaning plates can contact one of the surfaces of two adjacent sintered mesh filter elements, and when the bristles contact the surface of that sintered mesh filter element, the stop bars at both ends of the corresponding cleaning plate also fit snugly against the surface of that sintered mesh filter element.

3. The alkyl lithium filtration process of claim 2, wherein: The inner wall of the fixed ring is evenly provided with multiple deflection grooves, and an arc-shaped spring is provided in the deflection groove. The two ends of the arc-shaped spring are always located in the deflection groove, and in the initial state, the middle part of the arc-shaped spring can be located outside the deflection groove.

4. The alkyl lithium filtration process of claim 1, wherein: The filter tank is connected to a drain pipe at one end near the inlet pipe, and the drain pipe is close to the bottom of the filter tank. The bottom of the filter tank is connected to a sewage pipe.

5. The alkyl lithium filtration process of claim 2, wherein: The sintered mesh filter element is connected to a U-shaped handle at one end near the sealing cover. A pressure ring is installed on the sealing cover at a position opposite to the multiple handles, and when the sealing cover is closed, the pressure ring is able to fit close to the multiple handles.

6. The alkyl lithium filtration process of claim 1, wherein: The bottom of the filter tank is fixedly connected to two sets of support legs, and the two sets of support legs are symmetrically installed at the bottom of the filter tank.

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