Extraction saponification system adopting lithium precipitation mother liquor and saponification method thereof

Abstract

The invention discloses an extraction and saponification system adopting lithium precipitation mother liquor and a saponification method of the extraction and saponification system, and particularly relates to the technical field of extraction and saponification. The extraction and saponification system comprises a static tubular mixer, one end of the static tubular mixer communicates with an extraction agent guide pipe, and one side of the top of the static tubular mixer communicates with a lithium precipitation mother liquor guide pipe; a heat exchange box is arranged on one side of the static tubular mixer, the water outlet end, away from the extraction agent guide pipe, of the static tubular mixer communicates with a heat exchange pipe, one end of the heat exchange pipe penetrates through the heat exchange box to be connected with a flow guide pipe, and one side of the middle of the flow guide pipe communicates with a tubular saponification mixer; the end, away from the heat exchange pipe, of the flow guide pipe communicates with a clarification tank, and an inclined plate assembly is arranged in the middle of the clarification tank. According to the method, part of the lithium precipitation mother liquor is returned for extraction to be used as part of saponification alkali, and a set of equipment facilities are used for matching, so that the consumption of the liquid alkali in the extraction process production can be reduced, and the lithium precipitation mother liquor is recycled.

Description

Technical Field

[0001] This application relates to the field of extraction saponification technology, and more specifically, to an extraction saponification system and method using lithium precipitation mother liquor. Background Technology

[0002] Currently, the recovery of nickel, cobalt, manganese, and lithium from ternary lithium black powder mostly employs a leaching-extraction-evaporation-crystallization-precipitation process to recover various metals. During the extraction process, a 32% liquid alkali is used to saponify the extractant, giving it stronger extraction capabilities and purifying the metals. However, the main cost of this extraction process comes precisely from this 32% liquid alkali.

[0003] A search revealed an existing patent (publication number: CN119793362A) that discloses a continuous saponification device for an extractant, comprising a saponification kettle and a saponification clarification tank. The upper part of the saponification kettle is connected to the saponification clarification tank via an overflow pipe, and the bottom of the saponification kettle and the bottom of the saponification clarification tank are connected via a water phase reflux pipe. A stirring device is installed inside the bottom of the saponification kettle, and multiple extractant feed pipes extending into the vicinity of the stirring device are installed at the middle position of the upper part of the saponification kettle. Multiple liquid alkali feed pipes extending into the vicinity of the stirring device are installed around the extractant feed pipes at the upper part of the saponification kettle. The saponification kettle has an external jacketed structure, with a steam inlet connected to the lower part of the jacket space and a steam outlet connected to the upper part of the jacket space. A post-saponification method is provided at the upper part of the saponification clarification tank. This continuous saponification device and its saponification method for an extractant provide high saponification efficiency and low liquid alkali residue, resulting in less liquid alkali consumption, lower production costs, and better economic benefits.

[0004] The wastewater after extraction mainly consists of sodium sulfate and lithium sulfate. It needs to be evaporated and crystallized to recover sodium sulfate and enrich the lithium sulfate concentration from 2-4 g / L to about 15 g / L in the mother liquor. Then, the mother liquor is mixed with sodium carbonate solution to precipitate most of the lithium as lithium carbonate for further purification. However, the pH value of the lithium precipitation mother liquor is as high as 12 or above, containing a lot of carbonate ions. It often needs to be acidified with sulfuric acid to pH < 4 before being added to the sodium sulfate wastewater for evaporation and crystallization again. However, this method wastes sulfuric acid, increases the number of steps, and does not allow the excess alkali in the mother liquor to be used effectively.

[0005] Therefore, in response to the above problems, an extraction saponification system and saponification method using lithium precipitation mother liquor are proposed. Summary of the Invention

[0006] In order to overcome the above-mentioned defects of the prior art, this application provides an extraction saponification system and saponification method using lithium precipitation mother liquor to solve the problems mentioned in the background art.

[0007] To achieve the above objectives, this application provides the following technical solution: an extraction and saponification system using lithium precipitation mother liquor, comprising a static tubular mixer, one end of which is connected to an extractant conduit, the top side of which is connected to a lithium precipitation mother liquor conduit, a filter cylinder disposed in the middle of the lithium precipitation mother liquor conduit, a heat exchange box disposed on one side of the static tubular mixer, a heat exchange tube disposed at the water outlet end of the static tubular mixer away from the extractant conduit, the heat exchange tube being embedded in the heat exchange box, one end of the heat exchange tube passing through the heat exchange box and connected to a guide pipe, a tubular saponification mixer disposed in the middle side of the guide pipe, a clarification tank disposed at the end of the guide pipe away from the heat exchange tube, an inclined plate assembly disposed in the middle of the clarification tank, an automatic oil drain outlet disposed on the top side of the clarification tank, and an automatic drain outlet disposed on the bottom side of the clarification tank.

[0008] Preferably, the filter cartridge is equipped with a lithium ion sieve adsorption column, a cooling water inlet pipe is provided on the top side of the heat exchange box, a cooling water return pipe is provided on the bottom side of the heat exchange box, and a liquid pump is provided on the middle side of the guide pipe.

[0009] Preferably, a tapered converging guide head is provided at the inlet of the tubular saponification mixer, and segmented blades are arranged on the inner wall of the tubular saponification mixer. The spiral directions of multiple sets of segmented blades alternate sequentially. A rotating shaft is provided on one side of the water outlet of the tapered converging guide head. The rotating shaft is movably connected to the tubular saponification mixer through a bearing. A spiral impeller is provided on the side of the rotating shaft near the tapered converging guide head, and an auxiliary stirring rod is connected to the middle of the rotating shaft.

[0010] Preferably, the inclined plate assembly includes a drive box, a scissor lift frame, a connecting block, a strip groove, a drive cylinder, a connecting rod, an inclined plate, and a baffle plate. The drive box is disposed on both sides of the clarification tank, and the scissor lift frame is disposed inside the drive box. A connecting block is fixedly connected to each movable axis node of the scissor lift frame.

[0011] Preferably, each of the two sets of drive boxes has a strip groove on its opposite outer wall. Multiple sets of strip grooves are provided. The end of the connecting block extends through the strip groove to the outside of the drive box. A water baffle is connected to the middle of the connecting block. The outer wall of the water baffle is connected to the inner wall of the drive box and abuts against the strip groove. A drive cylinder is fixedly connected to the end of the connecting block. A connecting rod is movably connected to the middle of the two sets of drive cylinders through a bearing. An inclined plate is fixedly connected to the outer wall of the connecting rod.

[0012] Preferably, a pressure plate is slidably connected to the middle of the inner wall of the drive box, and a movable groove is provided at the bottom end of the pressure plate. The top end of the scissor lift frame is embedded in the movable groove, and the scissor lift frame is slidably connected to the movable groove. An electric push rod is fixedly connected to the top inner wall of the drive box, and the output end of the electric push rod is connected to the pressure plate.

[0013] Preferably, one end of the drive cylinder is movably connected to a rotating cylinder via a bearing, a fixed frame is fixedly connected to one side of the outer wall of the drive box, and a drive rod is connected to the middle of the fixed frame via a bearing. The drive rod passes through the interior of the drive cylinder and the rotating cylinder.

[0014] Preferably, a groove is provided in the middle of the drive rod, and a slider is fixedly connected to one side of the inner wall of the rotating cylinder. The slider is embedded in the groove, and the slider and the groove are slidably connected.

[0015] Preferably, a first bevel gear is fixedly connected to the outer wall of one end of the connecting rod, and a second bevel gear is fixedly connected to the outer wall of the rotating cylinder. The first and second bevel gears mesh with each other. An auxiliary scissor fork frame is provided on one side of the scissor fork movable frame. One end of the auxiliary scissor fork frame is slidably connected to the inner wall of the drive box. A threaded cylinder is connected to the central axis node of the auxiliary scissor fork frame through a connecting block. The threaded cylinder is sleeved on the outer wall of the drive rod. A threaded groove is provided on one side of the outer wall of the end of the drive rod. The threaded cylinder is threadedly connected to the threaded groove.

[0016] The method includes the following steps: Step 1: Preliminary mixing and saponification. The lithium precipitation mother liquor rich in sodium carbonate enters the filter cartridge through the lithium precipitation mother liquor conduit and flows through the internal lithium ion sieve adsorption column for filtration. The purified lithium precipitation mother liquor and extractant are simultaneously injected into the static tubular mixer through the extractant conduit. The fixed blades inside the static tubular mixer force the two-phase fluids to be cut and recombined to form a crude emulsion, thus completing the primary saponification reaction. Step 2: Heat exchange treatment. The temperature of the lithium mother liquor is relatively high, and the saponification reaction is also an exothermic reaction. The high-temperature mixture flows into the heat exchange tube from the outlet of the static tubular mixer. Cooling water is injected into the heat exchange box through the cooling water inlet pipe. After exchanging heat with the heat exchange tube in the opposite direction, it is discharged from the cooling water return pipe, thus cooling and exchanging heat for the mixture. Step 3: Secondary mixing and saponification. The coolant is delivered to the tubular saponification mixer through the guide pipe. The fluid is accelerated through the tapered guide head and impacts the spiral impeller to drive the shaft to rotate, which in turn drives the auxiliary stirring rod to enhance shearing. At the same time, the fluid is alternately divided and recombined by the dividing blades, the droplets are refined, and the saponification conversion rate is improved. Step 4: Oil and water separation. The oil is guided to the clarification tank for oil and water separation. The inclined plate assembly in the clarification tank enables the oil and water to be fully separated. When the oil phase thickens, the electric push rod pulls the pressure plate upward, and the top of the scissor lift retracts, which causes the connecting block to move inward. At the same time, the inclination angle of the inclined plate increases, thus accelerating the floating of the oil phase. When the water phase is turbid, the electric push rod pushes the pressure plate downward, and the top of the scissor lift expands, which causes the connecting block to move outward. At the same time, the distance between the inclined plates increases, and the inclination angle of the inclined plates decreases, prolonging the sedimentation of the water phase.

[0017] The technical effects and advantages of this application are as follows: 1. Compared with the prior art, the extraction saponification system and saponification method using lithium precipitation mother liquor use a portion of the lithium precipitation mother liquor as alkali for partial saponification by returning it to the extraction process, and using a complete set of equipment and facilities to cooperate with it. This can reduce the consumption of liquid alkali in the extraction process and also reuse the lithium precipitation mother liquor.

[0018] 2. Compared with existing technologies, this extraction and saponification system and method using lithium mother liquor replaces the traditional clarification tank with an inclined plate assembly in the clarification tank. In the same space, it can provide better phase separation effect, so that oil and water can be fully separated. When the oil phase thickens, the pressure plate is pulled up by an electric push rod, and the top of the scissor frame contracts, which causes the connecting block to move inward and the inclination angle of the inclined plate to increase, thereby accelerating the floating of the oil phase. When the water phase is turbid, the pressure plate is pushed down by an electric push rod, and the top of the scissor frame expands, which causes the connecting block to move outward and the plate spacing of the inclined plate to increase. At the same time, the inclination angle of the inclined plate decreases and the sedimentation of the water phase is prolonged. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of this application; Figure 2 This is a schematic diagram of the internal structure of the driver box in this application; Figure 3 This is a schematic diagram of the internal structure of the tubular saponification mixer of this application; Figure 4 This is a schematic diagram of the connection structure between the drive box and the inclined plate in this application; Figure 5 This is a schematic diagram of the connection structure between the heat exchange box and the heat exchange tubes in this application; Figure 6 This is a schematic diagram of the connection structure between the tubular saponification mixer and the clarification tank in this application; Figure 7 This is a schematic diagram of the structure of bevel gear No. 1 and bevel gear No. 2 in this application; Figure 8 This is a schematic diagram of the connection structure between the threaded cylinder and the threaded groove in this application.

[0020] The attached diagram is labeled as follows: 1. Static tubular mixer; 2. Extractant conduit; 3. Lithium precipitation mother liquor conduit; 4. Filter cartridge; 5. Heat exchanger box; 6. Heat exchanger tube; 7. Guide pipe; 8. Tubular saponification mixer; 9. Clarification tank; 901. Automatic oil drain; 902. Automatic drain; 10. Lithium-ion sieve adsorption column; 11. Cooling water inlet pipe; 12. Cooling water return pipe; 13. Liquid pump; 14. Conical tapered guide head; 15. Segmented blades; 16. Rotating shaft; 17. Spiral impeller; 18. 19. Auxiliary stirring rod; 20. Inclined plate assembly; 21. Drive box; 22. Scissor lift frame; 23. Connecting block; 24. Strip groove; 25. Drive cylinder; 26. Connecting rod; 27. Inclined plate; 28. Water baffle; 29. ​​Pressure plate; 30. Movable groove; 31. Electric push rod; 32. Rotating cylinder; 33. Fixed frame; 34. Drive rod; 35. Slide rail; 36. First bevel gear; 37. Second bevel gear; 38. Auxiliary scissor lift frame; 39. Threaded cylinder; 40. Threaded groove. Detailed Implementation

[0021] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0022] Example 1

[0023] As attached Figures 1 to 8 The illustrated extraction and saponification system using lithium precipitation mother liquor includes a static tubular mixer 1. One end of the static tubular mixer 1 is connected to an extractant conduit 2. The top side of the static tubular mixer 1 is connected to a lithium precipitation mother liquor conduit 3. A filter cylinder 4 is installed in the middle of the lithium precipitation mother liquor conduit 3. A heat exchange box 5 is installed on one side of the static tubular mixer 1. The water outlet end of the static tubular mixer 1 away from the extractant conduit 2 is connected to a heat exchange pipe 6. The heat exchange pipe 6 is embedded in the heat exchange box 5. One end of the heat exchange pipe 6 passes through the heat exchange box 5 and is connected to a guide pipe 7. A tubular saponification mixer 8 is connected to the middle side of the guide pipe 7. The end of the guide pipe 7 away from the heat exchange pipe 6 is connected to a clarification tank 9. An inclined plate assembly 19 is installed in the middle of the clarification tank 9. An automatic oil drain port 901 is installed on the top side of the clarification tank 9. An automatic drain outlet 902 is installed on the bottom side of the clarification tank 9.

[0024] In this process, lithium-containing mother liquor rich in sodium carbonate is mixed with an extractant for saponification. A static tubular mixer 1 is used. The lithium-containing mother liquor is injected into the static tubular mixer 1 through a lithium-containing mother liquor conduit 3, while the extractant is simultaneously injected into the static tubular mixer 1 through an extractant conduit 2. Fixed blades inside the static tubular mixer 1 forcibly cut and recombine the two phases, achieving initial mixing and saponification. Simultaneously, the lithium-containing mother liquor has a high temperature, and the saponification reaction is exothermic. The resulting high-temperature liquid flows into heat exchange tubes 6 and is then cooled by the cooling liquid inside a heat exchange box 5 to prevent excessive temperature from affecting the equipment's lifespan. The cooled mixture enters the tubular saponification mixer 8 through the guide pipe 7 for further mixing and saponification. Then it is guided to the clarification tank 9 for oil-water separation. The oil and water are fully separated by the inclined plate assembly 19 in the clarification tank 9. The oil and water are automatically discharged without manual operation through the automatic drain port 902 and the automatic oil drain port 901. By returning part of the lithium precipitation mother liquor to the extraction process as part of the saponification alkali, and using a complete set of equipment facilities, the consumption of liquid alkali in the extraction process can be reduced, and the lithium precipitation mother liquor can be reused.

[0025] Example 2

[0026] Based on Example 1, the solution in Example 1 will be further described in detail below with reference to the specific working method, such as... Figures 1 to 8 As shown below, see details: In a preferred embodiment, the filter cylinder 4 is equipped with a lithium ion adsorption column 10, a cooling water inlet pipe 11 is provided on the top side of the heat exchange box 5, a cooling water return pipe 12 is provided on the bottom side of the heat exchange box 5, and a liquid pump 13 is provided on the middle side of the guide pipe 7. The lithium ion adsorption column 10 can adsorb and filter lithium ions in the lithium precipitation mother liquor rich in sodium carbonate, thereby performing preliminary screening and filtration, recovering residual lithium in the mother liquor, and improving the overall lithium recovery rate. The preliminary mixed liquid flows into the heat exchange box 5 through the heat exchange pipe 6, and the cooling water is injected into the box through the cooling water inlet pipe 11. After exchanging heat with the mixed liquid in the heat exchange pipe 6, it is discharged from the cooling water return pipe 12 to cool the mixed liquid. The liquid pump 13 plays a driving and guiding role.

[0027] In a preferred embodiment, a tapered converging guide head 14 is provided at the inlet of the tubular saponification mixer 8. Dividing blades 15 are arranged on the inner wall of the tubular saponification mixer 8, with multiple sets of dividing blades 15 alternating in spiral direction. A rotating shaft 16 is provided on one side of the outlet end of the tapered converging guide head 14. The rotating shaft 16 is movably connected to the tubular saponification mixer 8 via a bearing. A spiral impeller 17 is provided on the side of the rotating shaft 16 near the tapered converging guide head 14. An auxiliary stirring rod 1 is connected to the middle of the rotating shaft 16. 8. After cooling, the mixture is accelerated into the tubular saponification mixer 8 through the conical tapered guide head 14. The fluid impacts the spiral impeller 17, thereby driving the rotating shaft 16 to rotate. The rotating shaft 16 drives the auxiliary stirring rod 18 to stir. In conjunction with the spiral segmented blades 15 fixed inside the tubular saponification mixer 8, multiple mixing is carried out to further enhance the mixing. The hydraulically self-driven spiral impeller 17 achieves zero-energy mixing enhancement, and the microdroplet particle size is further reduced, thereby shortening the saponification reaction time and improving the conversion rate.

[0028] In a preferred embodiment, the inclined plate assembly 19 includes a drive box 20, a scissor lift frame 21, a connecting block 22, a strip groove 23, a drive cylinder 24, a connecting rod 25, an inclined plate 26, and a baffle plate 27. The drive box 20 is disposed on both sides of the clarification tank 9. The scissor lift frame 21 is disposed inside the drive box 20. A connecting block 22 is fixedly connected to each of the movable axis nodes of the scissor lift frame 21. One side of the scissor lift frame 21 is slidably connected to the drive box 20. The scissor lift frame 21 is a movable scissor structure. During the unfolding and retraction process, the connecting blocks 22 at the nodes are always equidistantly arranged.

[0029] In a preferred embodiment, each of the two sets of drive boxes 20 has a strip groove 23 on one side of its outer wall. Multiple sets of strip grooves 23 are provided. The end of the connecting block 22 extends through the strip groove 23 to the outside of the drive box 20. A water-blocking plate 27 is connected to the middle of the connecting block 22. The outer wall of the water-blocking plate 27 is connected to the inner wall of the drive box 20, and the water-blocking plate 27 abuts against the strip groove 23. A drive cylinder 24 is fixedly connected to the end of the connecting block 22. A connecting rod 25 is movably connected to the middle of the two sets of drive cylinders 24 via a bearing. The outer wall of the connecting rod 25 is fixedly connected to the inclined plate 26. The connecting block 22 can move in translational motion as the scissor lift frame 21 retracts or expands. While the connecting block 22 moves along the strip groove 23, it drives the drive cylinder 24 and the baffle plate 27 to move in translational motion synchronously. The baffle plate 27 acts as a barrier to prevent liquid from entering the drive box 20. While the drive cylinder 24 moves, it can drive the connecting rod 25 and the inclined plate 26 to move in synchronization, thereby realizing the equal-distance adjustment of the distance between each set of inclined plates 26.

[0030] In a preferred embodiment, a pressure plate 28 is slidably connected to the middle of the inner wall of the drive box 20. A movable groove 29 is provided at the bottom end of the pressure plate 28. The top end of the scissor lift frame 21 is embedded in the movable groove 29, and the scissor lift frame 21 is slidably connected to the movable groove 29. An electric push rod 30 is fixedly connected to the top inner wall of the drive box 20. The output end of the electric push rod 30 is connected to the pressure plate 28. When the turbidity of the lithium precipitation mother liquor in the aqueous phase increases, the output end of the electric push rod 30 can push the pressure plate 28 downwards. The movable groove 29 at the bottom of the pressure plate 28 causes the top end of the scissor lift frame 21 to expand outwards, thereby realizing the unfolding function of the scissor lift frame 21. This increases the spacing between the connecting blocks 22, causing the connecting blocks 22 to move the drive cylinder 24, which in turn expands the spacing between the connecting rod 25 and the inclined plate 26, thus extending the sedimentation path of the aqueous phase and improving the solid-liquid separation effect. When the thickness of the oil phase layer increases, the electric push rod 30 pulls the pressure plate 28 upward, and the pressure plate 28 pulls the top of the scissor frame 21 to retract inward through the movable groove 29, causing the connecting blocks 22 to move the drive cylinder 24 closer to the center, forcing the connecting rod 25 to deflect with the bearing as the fulcrum. The inclination angle of the inclined plate 26 fixed to the connecting rod 25 increases accordingly. Increasing the inclination angle accelerates the oil phase to slide along the surface of the inclined plate 26 to the oil collection area, shortening the separation time.

[0031] In a preferred embodiment, one end of the drive cylinder 24 is movably connected to the rotating cylinder 31 via a bearing, and a fixing frame 32 is fixedly connected to one side of the outer wall of the drive box 20. A drive rod 33 is connected to the middle of the fixing frame 32 via a bearing. The drive rod 33 passes through the interior of the drive cylinder 24 and the rotating cylinder 31. The rotating cylinder 31 can move synchronously with the drive cylinder 24, and the drive rod 33 serves to support the rotating cylinder 31. The surfaces of the drive rod 33, the drive cylinder 24, and the rotating cylinder 31 are all provided with anti-corrosion coatings, as are the structures in contact with the liquid.

[0032] In a preferred embodiment, a groove 34 is provided in the middle of the drive rod 33, and a slider 35 is fixedly connected to one side of the inner wall of the rotating cylinder 31. The slider 35 is embedded in the groove 34 and is slidably connected to the groove 34. The slider 35 is embedded in the groove 34 so that the drive rod 33 can rotate and drive the rotating cylinder 31 to rotate synchronously. The rotating cylinder 31 can move synchronously with the drive cylinder 24 while rotating.

[0033] In a preferred embodiment, a first bevel gear 36 is fixedly connected to the outer wall of one end of the connecting rod 25, and a second bevel gear 37 is fixedly connected to the outer wall of the rotating cylinder 31. The first bevel gear 36 and the second bevel gear 37 mesh with each other. An auxiliary scissor fork frame 38 is provided on one side of the scissor fork movable frame 21. One end of the auxiliary scissor fork frame 38 is slidably connected to the inner wall of the drive box 20. A threaded cylinder 39 is connected to the central axis node of the auxiliary scissor fork frame 38 through a connecting block 22. The threaded cylinder 39 is sleeved on the outer wall of the drive rod 33. A threaded groove 40 is provided on one side of the outer wall of the end of the drive rod 33. The threaded cylinder 39 is threadedly connected to the threaded groove 40. The auxiliary scissor fork frame 38 can also be extended or retracted under the drive of the pressure plate 28. At the same time, one end of the auxiliary scissor fork frame 38 is slidably connected to the inner wall of the drive box 20. The sliding connection of the wall causes the connecting block 22 connected to it to generate a certain displacement during the unfolding process, thereby driving the threaded cylinder 39 to move synchronously. The helix angle between the threaded cylinder 39 and the threaded groove 40 is greater than the friction angle and does not have self-locking property. This allows the threaded cylinder 39 to drive the drive rod 33 to rotate during the movement. The rotation of the drive rod 33 drives the rotating cylinder 31 and the second bevel gear 37 to rotate synchronously. The rotation of the second bevel gear 37 drives the first bevel gear 36 to rotate, thereby causing the connecting rod 25 and the inclined plate 26 to shift at an angle. This achieves the adjustment of the spacing of the inclined plates 26 while shifting the angle. When the oil phase thickens, the plate spacing is reduced while the tilt angle is increased to accelerate the floating of the oil phase. When the water phase is turbid, the plate spacing is increased while the tilt angle is decreased to prolong the settling time of the water phase.

[0034] As a preferred embodiment, the saponification method includes the following steps: Step 1: Preliminary mixing and saponification. The lithium precipitation mother liquor rich in sodium carbonate enters the filter cylinder 4 through the lithium precipitation mother liquor conduit 3 and flows through the lithium ion adsorption column 10 inside for filtration. The purified lithium precipitation mother liquor and extractant are simultaneously injected into the static tubular mixer 1 through the extractant conduit 2. The fixed blades inside the static tubular mixer 1 force the two-phase fluid to be cut and recombined to form a crude emulsion, thus completing the primary saponification reaction. Step 2: Heat exchange treatment. The temperature of the lithium mother liquor is relatively high, and the saponification reaction is also an exothermic reaction. The high-temperature mixture flows into the heat exchange tube 6 from the outlet of the static tubular mixer 1. Cooling water is injected into the heat exchange box 5 through the cooling water inlet pipe 11. After exchanging heat with the heat exchange tube 6 in the opposite direction, it is discharged from the cooling water return pipe 12 to cool and exchange heat in the mixture. Step 3: Secondary mixing and saponification. The coolant is delivered to the tubular saponification mixer 8 through the guide pipe 7. The fluid is accelerated by the conical tapered guide head 14, impacts the spiral impeller 17 to drive the rotating shaft 16 to rotate, and drives the auxiliary stirring rod 18 to enhance shearing. At the same time, the fluid is alternately divided and recombined by the dividing blades 15, the droplets are refined, and the saponification conversion rate is improved. Step 4: Oil and water phase separation. The oil is guided to the clarifier 9 for oil and water phase separation. The inclined plate assembly 19 in the clarifier 9 enables the oil and water to be fully separated. When the oil phase thickens, the electric push rod 30 pulls the pressure plate 28 upward. The top of the scissor lift frame 21 contracts, which causes the connecting block 22 to move inward. At the same time, the inclination angle of the inclined plate 26 increases, thereby accelerating the floating of the oil phase. When the water phase is turbid, the electric push rod 30 pushes the pressure plate 28 downward. The top of the scissor lift frame 21 expands, which causes the connecting block 22 to move outward. At the same time, the plate spacing of the inclined plate 26 increases, and the inclination angle of the inclined plate 26 decreases, prolonging the sedimentation of the water phase.

[0035] The working process of this application is as follows: First, the lithium precipitation mother liquor rich in sodium carbonate enters the filter cylinder 4 through the lithium precipitation mother liquor conduit 3, and flows through the lithium ion sieve adsorption column 10 inside for filtration. The purified lithium precipitation mother liquor and extractant are simultaneously injected into the static tubular mixer 1 through the extractant conduit 2. The fixed blades inside the static tubular mixer 1 force the two-phase fluids to be cut and recombined to form a crude emulsion, completing the primary saponification reaction. The lithium ion adsorption column 10 can adsorb and filter the lithium ions in the sodium carbonate-rich lithium precipitation mother liquor, thereby performing preliminary screening and filtration to recover residual lithium in the mother liquor. To improve the overall lithium recovery rate, the initial mixture flows into the heat exchange box 5 through the heat exchange tube 6. Cooling water is injected into the box through the cooling water inlet pipe 11, and after counter-current heat exchange with the mixture in the heat exchange tube 6, it is discharged from the cooling water return pipe 12 to cool the mixture. After cooling, the mixture is accelerated into the tubular saponification mixer 8 through the conical tapered guide head 14. The fluid impacts the spiral impeller 17, thereby driving the rotating shaft 16 to rotate. The rotating shaft 16 drives the auxiliary stirring rod 18 to stir, and together with the spiral segmented blades 15 fixed inside the tubular saponification mixer 8, multiple mixing is carried out to further enhance the mixing. The hydraulically self-driven helical impeller 17 achieves zero-energy mixing enhancement, further reducing the droplet size, thereby shortening the saponification reaction time and increasing the conversion rate. When the turbidity of the lithium precipitation mother liquor increases, the output end of the electric push rod 30 can push the pressure plate 28 downward. The movable groove 29 at the bottom of the pressure plate 28 drives the top of the scissor lift frame 21 to expand outward, thus realizing the unfolding effect of the scissor lift frame 21. This increases the spacing between the connecting blocks 22, and the connecting blocks 22 drive the drive cylinder 24 to shift, thereby increasing the plate spacing between the connecting rod 25 and the inclined plate 26. Extending the sedimentation path of the aqueous phase improves the solid-liquid separation effect. When the thickness of the oil phase layer increases, the electric push rod 30 pulls the pressure plate 28 upward. The pressure plate 28 pulls the top of the scissor frame 21 to retract inward through the movable groove 29, thereby causing the connecting block 22 to drive the drive cylinder 24 to move closer to the center. This forces the connecting rod 25 to deflect around the bearing as the fulcrum. The inclination angle of the inclined plate 26 fixed to the connecting rod 25 increases accordingly. Increasing the inclination angle accelerates the oil phase to slide along the surface of the inclined plate 26 to the oil collection area, shortening the separation time. The above is the working principle of this extraction and saponification system and its saponification method using lithium mother liquor.

Claims

1. An extraction and saponification system using lithium precipitation mother liquor, comprising a static tubular mixer (1), characterized in that: One end of the static tubular mixer (1) is connected to an extractant conduit (2), and the top side of the static tubular mixer (1) is connected to a lithium precipitation mother liquor conduit (3). A filter cartridge (4) is installed in the middle of the lithium precipitation mother liquor conduit (3). A heat exchange box (5) is installed on one side of the static tubular mixer (1). The water outlet end of the static tubular mixer (1) away from the extractant conduit (2) is connected to a heat exchange tube (6), which is embedded in the heat exchange box (5). One end of the heat exchange tube (6) passes through the heat exchange box (5) and is connected to the guide tube (7). One side of the middle of the guide tube (7) is connected to the tubular saponification mixer (8). The end of the guide tube (7) away from the heat exchange tube (6) is connected to the clarification tank (9). The middle of the clarification tank (9) is provided with an inclined plate assembly (19). One side of the top of the clarification tank (9) is provided with an automatic oil drain (901). One side of the bottom of the clarification tank (9) is provided with an automatic drain (902).

2. The extraction and saponification system using lithium precipitation mother liquor according to claim 1, characterized in that: The filter cylinder (4) is equipped with a lithium ion sieve adsorption column (10), a cooling water inlet pipe (11) is provided on the top side of the heat exchange box (5), a cooling water return pipe (12) is provided on the bottom side of the heat exchange box (5), and a liquid pump (13) is provided on the middle side of the guide pipe (7).

3. The extraction and saponification system using lithium precipitation mother liquor according to claim 1, characterized in that: The tubular saponification mixer (8) is provided with a conical tapered guide head (14) at its inlet. The inner wall of the tubular saponification mixer (8) is provided with dividing blades (15). The spiral directions of the multiple sets of dividing blades (15) alternate sequentially. A rotating shaft (16) is provided on one side of the outlet end of the conical tapered guide head (14). The rotating shaft (16) is movably connected to the tubular saponification mixer (8) through a bearing. A spiral impeller (17) is provided on the side of the rotating shaft (16) near the conical tapered guide head (14). An auxiliary stirring rod (18) is connected to the middle of the rotating shaft (16).

4. The extraction and saponification system using lithium precipitation mother liquor according to claim 1, characterized in that: The inclined plate assembly (19) includes a drive box (20), a scissor lift frame (21), a connecting block (22), a strip groove (23), a drive cylinder (24), a connecting rod (25), an inclined plate (26), and a baffle plate (27). The drive box (20) is located on both sides of the clarifier (9). The drive box (20) contains a scissor lift frame (21), and the movable axis nodes of the scissor lift frame (21) are all fixedly connected to the connecting blocks (22).

5. The extraction and saponification system using lithium precipitation mother liquor according to claim 4, characterized in that: Both sets of drive boxes (20) have a strip groove (23) on their opposite outer walls. There are multiple sets of the strip groove (23). The end of the connecting block (22) extends through the strip groove (23) to the outside of the drive box (20). A water baffle (27) is connected to the middle of the connecting block (22). The outer wall of the water baffle (27) is connected to the inner wall of the drive box (20), and the water baffle (27) abuts against the strip groove (23). A drive cylinder (24) is fixedly connected to the end of the connecting block (22). A connecting rod (25) is movably connected to the middle of the two sets of drive cylinders (24) through a bearing. An inclined plate (26) is fixedly connected to the outer wall of the connecting rod (25).

6. The extraction and saponification system using lithium precipitation mother liquor according to claim 5, characterized in that: A pressure plate (28) is slidably connected to the middle of the inner wall of the drive box (20). A movable groove (29) is provided at the bottom end of the pressure plate (28). The top end of the scissor lift frame (21) is embedded in the movable groove (29), and the scissor lift frame (21) is slidably connected to the movable groove (29). An electric push rod (30) is fixedly connected to the top inner wall of the drive box (20). The output end of the electric push rod (30) is connected to the pressure plate (28).

7. The extraction and saponification system using lithium precipitation mother liquor according to claim 6, characterized in that: One end of the drive cylinder (24) is movably connected to the rotating cylinder (31) via a bearing. A fixed frame (32) is fixedly connected to one side of the outer wall of the drive box (20). A drive rod (33) is connected to the middle of the fixed frame (32) via a bearing. The drive rod (33) passes through the interior of the drive cylinder (24) and the rotating cylinder (31).

8. The extraction and saponification system using lithium precipitation mother liquor according to claim 7, characterized in that: The drive rod (33) has a groove (34) in the middle, and a slider (35) is fixedly connected to one side of the inner wall of the rotating cylinder (31). The slider (35) is embedded in the groove (34), and the slider (35) and the groove (34) are slidably connected.

9. The extraction and saponification system using lithium precipitation mother liquor according to claim 8, characterized in that: One end of the connecting rod (25) is fixedly connected to a first bevel gear (36), and the outer wall of the rotating cylinder (31) is fixedly connected to a second bevel gear (37). The first bevel gear (36) and the second bevel gear (37) mesh with each other. An auxiliary scissor frame (38) is provided on one side of the scissor frame (21). One end of the auxiliary scissor frame (38) is slidably connected to the inner wall of the drive box (20). A threaded cylinder (39) is connected to the central axis node of the auxiliary scissor frame (38) through a connecting block (22). The threaded cylinder (39) is sleeved on the outer wall of the drive rod (33). A threaded groove (40) is provided on one side of the outer wall of the end of the drive rod (33). The threaded cylinder (39) and the threaded groove (40) are threadedly connected.

10. A saponification method using an extraction saponification system with lithium precipitation mother liquor, employing the extraction saponification system with lithium precipitation mother liquor as described in any one of claims 1-9, characterized in that: The method includes the following steps: Step 1: Preliminary mixing and saponification. The lithium precipitation mother liquor rich in sodium carbonate enters the filter cylinder (4) through the lithium precipitation mother liquor conduit (3) and flows through the lithium ion sieve adsorption column (10) inside for filtration. The purified lithium precipitation mother liquor and extractant are simultaneously injected into the static tubular mixer (1) through the extractant conduit (2). The two-phase fluid is forcibly cut and recombined by the fixed blades inside the static tubular mixer (1) to form a crude emulsion and complete the primary saponification reaction. Step 2: Heat exchange treatment. The temperature of the lithium mother liquor is relatively high, and the saponification reaction is also an exothermic reaction. The high-temperature mixture flows into the heat exchange tube (6) from the outlet of the static tubular mixer (1). Cooling water is injected into the heat exchange box (5) through the cooling water inlet pipe (11). After exchanging heat with the heat exchange tube (6) in the opposite direction, it is discharged from the cooling water return pipe (12) to cool and exchange heat in the mixture. Step 3: Secondary mixing and saponification. The coolant is transported to the tubular saponification mixer (8) through the guide pipe (7). The fluid is accelerated through the conical tapered guide head (14) and impacts the spiral impeller (17) to drive the rotating shaft (16) to rotate, which drives the auxiliary stirring rod (18) to enhance shearing. At the same time, the fluid is alternately divided and recombined by the dividing blades (15), the droplets are refined, and the saponification conversion rate is improved. Step 4: Oil and water phase separation. The oil and water are guided to the clarifier (9) for oil and water phase separation. The oil and water are fully separated by the inclined plate assembly (19) in the clarifier (9). When the oil phase thickens, the pressure plate (28) is pulled up by the electric push rod (30). The top of the scissor lift frame (21) contracts, which causes the connecting block (22) to move inward. At the same time, the inclination angle of the inclined plate (26) increases, which accelerates the floating of the oil phase. When the water phase is turbid, the pressure plate (28) is pushed down by the electric push rod (30). The top of the scissor lift frame (21) expands, which causes the connecting block (22) to move outward. At the same time, the plate spacing of the inclined plate (26) increases. Meanwhile, the inclination angle of the inclined plate (26) decreases, which prolongs the sedimentation of the water phase.

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