Purification equipment and purification process for recovering lithium carbonate from lithium iron phosphate battery

Abstract

The invention relates to the technical field of lithium iron phosphate batteries, and particularly discloses purification equipment and a purification process for recycling lithium carbonate from lithium iron phosphate batteries, the purification equipment comprises a crushing box and a grinding box, the grinding box is arranged below the crushing box, two crushing rollers are mounted in the crushing box, and a fixing frame is mounted on the outer wall of the crushing box; a filter box is arranged in the fixing frame, the top of the fixing frame is connected with a first moving frame through a telescopic mechanism, a second moving frame is installed in the first moving frame, two placing frames are placed above the second moving frame, and a processing mechanism is arranged at the top of the crushing box. According to the waste battery crushing equipment, through the arranged processing mechanism, the batteries can be extruded in advance before being crushed, so that the subsequent crushing process is easier to carry out, the energy consumption of the crushing equipment can be reduced, the crushing efficiency can be improved, the treatment time of the waste batteries can be shortened, and the generation of dust can be reduced; and positive significance is brought to preparation and purification of lithium carbonate.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium iron phosphate batteries, and in particular to a purification device and a purification process for recovering lithium carbonate from lithium iron phosphate batteries. Background Art

[0002] Lithium iron phosphate battery is a lithium-ion battery that uses lithium iron phosphate as the positive electrode material and carbon as the negative electrode material. The electrochemical performance of the positive electrode material of lithium iron phosphate battery is relatively stable, with a stable charging and discharging platform. The structure of the battery will not change during the charging and discharging process, and it will not burn or explode. Even under special conditions such as short circuit, overcharge, extrusion, and acupuncture, it is still very safe. Therefore, lithium iron phosphate batteries are widely used in many fields due to their excellent performance. With the rapid development of electric vehicles and energy storage systems, the demand for lithium iron phosphate batteries continues to grow, and the demand for lithium carbonate has also increased. By recycling lithium carbonate from waste batteries, production costs can be reduced and economic benefits can be improved. At the same time, the recycling industry itself can also create employment opportunities and promote the development of related industrial chains.

[0003] In the process of recovering and purifying lithium carbonate in waste lithium iron phosphate batteries in the prior art, the waste lithium iron phosphate batteries need to be crushed first, and then the lithium carbonate contained in the waste lithium iron phosphate batteries is prepared and purified through a series of processing steps; since the shell and plate of the lithium iron phosphate battery are relatively hard, if they are directly put into the relevant crushing equipment for crushing, the crushing time of the battery will be prolonged, the energy consumption of the crushing equipment will be increased, and more smoke and dust will be generated, thereby affecting the preparation and purification efficiency of the lithium carbonate in the lithium iron phosphate battery. Summary of the invention

[0004] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a purification device and a purification process for recovering lithium carbonate from lithium iron phosphate batteries.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: A purification device for recycling lithium carbonate from lithium iron phosphate batteries comprises a crushing box and a grinding box, wherein the grinding box is arranged below the crushing box, two crushing rollers are rotatably installed inside the crushing box, a fixing frame is installed on the outer wall of the crushing box, a filter box is arranged inside the fixing frame and between the crushing box and the grinding box, a first moving frame is connected to the top of the fixing frame through a telescopic mechanism, a second moving frame is slidably installed inside the first moving frame, two placement frames for temporarily storing lithium iron phosphate batteries are placed above the second moving frame, and a processing mechanism for pre-processing multiple lithium iron phosphate batteries inside the placement frames is arranged on the top of the crushing box.

[0006] Optionally, the processing mechanism includes two brackets installed on the top of the crushing box, the outer walls of the two brackets on the side close to each other are each provided with a first slide groove, the interiors of the two first slide grooves are each provided with a first slider, and the ends of the two first sliders away from the first slide groove are jointly provided with a movable plate.

[0007] Optionally, the bottom end of the movable plate is connected to a movable frame via two electric telescopic rods, four inner walls of the movable frame are provided with second sliding grooves, second sliders are installed inside the four second sliding grooves, a rotating plate is installed between two matching second sliders for common rotation, and a dust suction port and an exhaust port are respectively provided at the bottom ends of the two rotating plates.

[0008] Optionally, the telescopic mechanism includes two first grooves opened on the top of the fixed frame, the interior of the two first grooves are rotatably installed with double-headed screws, the outer walls of the two double-headed screws are threadedly installed with two moving blocks, the tops of the two moving blocks are rotatably installed with connecting rods, and the tops of the two connecting rods are hinged to the bottom end of the first moving frame.

[0009] Optionally, the two inner walls of the first movable frame are provided with second grooves, screw rods are rotatably installed inside the two second grooves, both ends of the second movable frame are threadedly connected to the outer walls of the two screw rods, and two limit rods are installed at the top of the first movable frame near the crushing box.

[0010] Optionally, a partition is installed at the center of the top of the second movable frame, and electromagnets are installed on the outer walls on both sides away from the partition. After power is turned on, the two electromagnets are magnetically fixed to the placement frames adjacent to them.

[0011] Optionally, two groups of first sealing plates are rotatably mounted inside the second movable frame, and the two groups of first sealing plates are respectively located directly below the two placement frames.

[0012] Optionally, two second sealing plates are rotatably mounted inside the two placement frames, and a limiting plate is rotatably mounted on one end of the two placement frames close to the crushing box.

[0013] Optionally, third slide grooves are provided on inner walls on both sides of the fixing frame, third sliding blocks are installed inside the two third slide grooves, and ends of the two third sliding blocks away from the third slide grooves are connected to the filter box.

[0014] Optionally, a purification process for recovering lithium carbonate from a lithium iron phosphate battery comprises the purification device described above, and the purification process further comprises the following steps: Step 1: Raw material pretreatment: With the help of two electric telescopic rods, the telescopic ends extend downward to drive the mobile frame and two rotating plates to squeeze the neatly arranged batteries inside one of the placement frames; Step 2: Crushing and screening. After squeezing the multiple batteries in the placement frame, the two first sliders of the control processing mechanism drive the rotating plate to push the batteries in the placement frame into the crushing box for crushing. The batteries after the first crushing process are discharged downward to the inside of the filter box for screening and filtering, and finally fall into the inside of the grinding box for further crushing. Step 3: Impurity removal and purification. After the battery is further crushed in the grinding box, the metal impurities in the raw materials are removed by chemical reaction. Then, the ferromagnetic metal impurities and impurity particles of different sizes are removed by magnetic separation, screening and filtration. Finally, the pH value of the solution is adjusted in stages to selectively precipitate impurities. Step 4: lithium precipitation and carbonization, adding the lithium sulfate solution prepared in step 3 to the sodium carbonate solution, maintaining appropriate stirring, so that the lithium ions and carbonate ions combine to form lithium carbonate precipitation, and after the reaction is completed, the lithium carbonate precipitation is separated from the mother liquor by centrifugation and filtration. The precipitate is washed, dried, etc. to obtain a lithium carbonate product, and then the recovered lithium carbonate is ground and dissolved in a solvent to form a lithium carbonate solution, and carbon dioxide gas is introduced into the lithium carbonate solution to react with lithium carbonate to generate lithium bicarbonate; Step 5: thermal decomposition and drying. The lithium bicarbonate solution generated in step 4 is thermally decomposed to decompose it into lithium carbonate, carbon dioxide and water. The lithium carbonate is separated from the solution by evaporation and crystallization. The lithium carbonate obtained after the thermal decomposition is dried to remove the water therein to obtain a purified lithium carbonate product.

[0015] The beneficial effects of the present invention are: 1. In the present invention, by cooperating with the processing mechanism and the placement frame, the battery can be extruded before being crushed, so that the shell, plate and other components of the waste lithium iron phosphate battery can be initially deformed or destroyed, making the subsequent crushing process easier to carry out. This can not only reduce the energy consumption of the crushing equipment, but also improve the crushing efficiency, shorten the processing time of waste batteries, and to a certain extent reduce the generation of dust, reduce the harm to the environment and human body, and bring positive significance to the preparation and purification of lithium carbonate in lithium iron phosphate batteries.

[0016] 2. In the present invention, while the processing mechanism is squeezing the battery, the agglomerated impurities attached to the surface of the battery can also be squeezed and destroyed, and the two first sliders can move back and forth inside the corresponding first slide groove, thereby driving the movable frame and the two rotating plates to move back and forth and adjust on the top of one of the placement frames. While squeezing the battery inside one of the placement frames, it also has the effect of rubbing the battery and driving multiple batteries to rotate inside the placement frame, so that the movable frame and the two rotating plates can have a better squeezing effect on multiple batteries, and impurities attached to the surface of some batteries can be effectively removed by friction.

[0017] 3. In the present invention, during the process of squeezing and rubbing a plurality of batteries by means of the movable frame and the two rotating plates, the external preset dust suction device can be controlled to start, so that the dust suction port can automatically suck out and clean the impurities cleaned from the inside of the placement frame at the same time, thereby preventing these cleaned impurities from entering the crushing box together; and the dust suction port can also suck out harmful gases that may exist during the battery squeezing process, thereby preventing the harmful gases from escaping into the processing environment and causing harm to the workers.

[0018] 4. In the present invention, when the battery enters the crushing box for crushing, the rotatable and adjustable rotating plate can be controlled to rotate and reset to a horizontal state, and the two electric telescopic rods are controlled to drive the movable frame and the two rotating plates to move downward to the top of the crushing box, so as to seal the top of the crushing box to prevent the battery components from splashing outward from the top of the crushing box during the crushing process; and the exhaust port can be controlled at the same time to discharge nitrogen into the crushing box to control the oxygen concentration inside the crushing box and prevent the generation of flammable volatile gases, thereby improving the safety of the battery crushing process. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to facilitate understanding by those skilled in the art, the present invention is further described below with reference to the accompanying drawings.

[0020] Figure 1 This is a schematic diagram of the overall structure of a purification device for recovering lithium carbonate from lithium iron phosphate batteries proposed by the present invention; Figure 2 for Figure 1 A schematic diagram of the structure from another angle; Figure 3 It is a structural schematic diagram of the crushing box in the present invention; Figure 4 It is a structural schematic diagram of the processing mechanism in the present invention; Figure 5 for Figure 4 A schematic diagram of the structure in which two rotating plates are separated from the moving frame; Figure 6 It is a schematic diagram of the structure of the bottom of two rotating plates in the present invention; Figure 7 It is a schematic diagram of the structure of the fixed frame and the first movable frame in the present invention; Figure 8 It is a structural schematic diagram of the filter box in the present invention; Fig. 9 It is a structural schematic diagram of the telescopic mechanism in the present invention; Fig.10 It is a structural schematic diagram of the first moving frame in the present invention; Fig.11 It is a schematic structural diagram of the second moving frame and two placing frames in the present invention.

[0021] In the figure: 1. crushing box; 2. grinding box; 3. bracket; 4. first slide; 5. moving plate; 6. moving frame; 7. first moving frame; 8. second moving frame; 9. fixed frame; 10. filter box; 11. crushing roller; 12. electric telescopic rod; 13. rotating plate; 14. first slider; 15. second slider; 16. second slide; 17. first groove; 18. connecting rod; 19. third slide; 20. third slider; 21. double-headed screw; 22. moving block; 23. placing frame; 24. second groove; 25. screw rod; 26. limiting rod; 27. partition; 28. electromagnet; 29. ​​first sealing plate; 30. second sealing plate; 31. limiting plate; 32. dust suction port; 33. exhaust port. DETAILED DESCRIPTION

[0022] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] Reference Figure 1-Figure 11 A purification device for recycling lithium carbonate from lithium iron phosphate batteries comprises a crushing box 1 and a grinding box 2, the grinding box 2 is arranged below the crushing box 1, two crushing rollers 11 are rotatably installed inside the crushing box 1, a fixing frame 9 is installed on the outer wall of the crushing box 1, a filter box 10 is arranged inside the fixing frame 9 and between the crushing box 1 and the grinding box 2, a first moving frame 7 is connected to the top of the fixing frame 9 through a telescopic mechanism, a second moving frame 8 is slidably installed inside the first moving frame 7, two placement frames 23 for temporarily storing lithium iron phosphate batteries are placed above the second moving frame 8, and a processing mechanism for pre-processing multiple lithium iron phosphate batteries inside the placement frame 23 is arranged on the top of the crushing box 1.

[0024] As a technical optimization solution of the present invention, the processing mechanism includes two brackets 3 installed on the top of the crushing box 1, and the outer walls of the two brackets 3 on the side close to each other are each provided with a first slide groove 4, and the first sliders 14 are each installed inside the two first slide grooves 4, and the two first sliders 14 are commonly installed with a moving plate 5 at one end away from the first slide groove 4. The two first linear motors are preset inside the two first slide grooves 4, and the two first linear motors can drive the two first sliders 14 to move back and forth inside the corresponding first slide grooves 4, and drive the moving plate 5 to move and adjust between the two brackets 3.

[0025] As a technical optimization scheme of the present invention, the bottom end of the movable plate 5 is connected to the movable frame 6 through two electric telescopic rods 12, the four inner walls of the movable frame 6 are provided with second slide grooves 16, the interiors of the four second slide grooves 16 are provided with second sliders 15, a rotating plate 13 is installed between two matching second sliders 15 for common rotation, and the bottom ends of the two rotating plates 13 are respectively provided with a dust suction port 32 and an exhaust port 33. The telescopic ends of the two electric telescopic rods 12 can drive the mobile frame 6 and the two rotating plates 13 to move up and down synchronously; second linear motors are preset inside the four second slides 16, and the four second linear motors can drive the four second sliders 15 to move back and forth and adjust inside the corresponding second slides 16; so that the two rotating plates 13 can be driven to move and adjust by the corresponding two second sliders 15; and first driving devices are preset inside the two second sliders 15, and the output ends of the two first driving devices are respectively connected to the rotating parts of one end of the two rotating plates 13, so that the two rotating plates 13 can be driven to rotate and adjust between the corresponding two second sliders 15; slots are pre-opened at the bottom ends of the two rotating plates 13, and dust suction heads and exhaust heads are respectively installed inside the two slots, and the dust suction heads and exhaust heads are connected to the relevant dust suction equipment and exhaust equipment preset outside through pipelines, and the dust suction heads and exhaust heads correspond to the positions of the dust suction port 32 and the exhaust port 33 respectively, so as to facilitate the subsequent dust suction and exhaust work of the dust suction port 32 and the exhaust port 33.

[0026] As a technical optimization scheme of the present invention, the telescopic mechanism includes two first grooves 17 opened on the top of the fixed frame 9, and the insides of the two first grooves 17 are rotatably installed with double-headed screws 21, and the outer walls of the two double-headed screws 21 are threadedly installed with two moving blocks 22, and the tops of the two moving blocks 22 are rotatably installed with connecting rods 18, and the tops of the two connecting rods 18 are hinged to the bottom end of the first moving frame 7. Two second driving devices are preset inside the fixed frame 9, and the output ends of the two second driving devices are respectively connected to one end of the two double-headed screws 21, so that the two double-headed screws 21 can be driven to rotate inside the corresponding first groove 17; during the rotation of the two double-headed screws 21, the corresponding two moving blocks 22 can be driven to move and adjust in the direction of approaching or moving away. When the two moving blocks 22 move in the direction of approaching, they can drive the two connecting rods 18 to rotate in the direction of approaching, and push the upper first moving frame 7 to move upward for adjustment; when the two moving blocks 22 move in the direction of moving away, they can drive the two connecting rods 18 to rotate in the direction of moving away, and pull the upper first moving frame 7 to move downward for adjustment.

[0027] As a technical optimization solution of the present invention, the two inner walls of the first moving frame 7 are provided with second grooves 24, and screw rods 25 are rotatably installed inside the two second grooves 24. Both ends of the second moving frame 8 are threadedly connected to the outer walls of the two screw rods 25, and two limit rods 26 are installed at the top of the first moving frame 7 near the crushing box 1. Two third driving devices are preset inside the first moving frame 7, and the output ends of the two third driving devices are respectively connected to one end of the two screw rods 25, which can drive the two screw rods 25 to rotate inside the corresponding second grooves 24, so that the second moving frame 8 can move back and forth inside the first moving frame 7 as the two screw rods 25 rotate.

[0028] As a technical optimization solution of the present invention, a partition 27 is installed at the center of the top of the second moving frame 8, and electromagnets 28 are installed on the outer walls on both sides away from the partition 27. After the two electromagnets 28 are powered on, they are magnetically fixed to the placement frames 23 close to them. After the placement frame 23 is placed on the top of the second moving frame 8 by a preset manipulator, it can be magnetically fixed by powering on the corresponding electromagnet 28 to avoid shaking during use.

[0029] As a technical optimization solution of the present invention, two groups of first sealing plates 29 are rotatably installed inside the second moving frame 8, and the two groups of first sealing plates 29 are respectively located directly below the two placement frames 23. A plurality of first driving devices are preset inside the second moving frame 8, and the output ends of the plurality of first driving devices are respectively connected to the rotating parts of one end of the two groups of first sealing plates 29, so as to drive the two groups of first sealing plates 29 to rotate and adjust inside the second moving frame 8.

[0030] As a technical optimization solution of the present invention, two second sealing plates 30 are rotatably installed inside the two placement frames 23, and a limit plate 31 is rotatably installed at one end of the two placement frames 23 close to the crushing box 1. Two second driving devices are preset inside the two placement frames 23, and the output ends of the two second driving devices are respectively connected to the rotating parts of one end of the two second sealing plates 30, so that the two second sealing plates 30 can be driven to rotate and adjust inside the corresponding placement frames 23; and a third driving device is also preset inside the two placement frames 23, and the output end of the third driving device is connected to the rotating part of one end of the limit plate 31, so that the limit plate 31 can be driven to rotate and adjust at one end of the placement frame 23.

[0031] As a technical optimization solution of the present invention, third slide grooves 19 are provided on the inner walls of both sides of the fixing frame 9, and third sliders 20 are installed inside the two third slide grooves 19, and the ends of the two third sliders 20 away from the third slide grooves 19 are connected to the filter box 10. Third linear motors are preset inside the two third slide grooves 19, and the two third linear motors can drive the two third sliders 20 to move and adjust inside the corresponding third slide grooves 19, and drive the filter box 10 to move back and forth inside the fixing frame 9; the filter box 10 is set to be rotatable at the bottom, which has the same structure as the two second sealing plates 30 set at the bottom of the placement frame 23 mentioned above.

[0032] As a technical optimization solution of the present invention, a purification process for recovering lithium carbonate from a lithium iron phosphate battery comprises the above-mentioned purification equipment, and the purification process further comprises the following steps: Step 1: Raw material pretreatment, with the help of the telescopic ends of the two electric telescopic rods 12 extending downward, driving the mobile frame 6 and the two rotating plates 13 to squeeze the neatly arranged batteries inside one of the placement frames 23; Step 2: Crushing and screening. After squeezing the multiple batteries in the placement frame 23, the two first sliders 14 of the control processing mechanism drive the rotating plate 13 to push the batteries in the placement frame 23 into the inside of the crushing box 1 for crushing. The batteries after the first crushing process are discharged downward to the inside of the filter box 10 for screening and filtering, and finally fall into the inside of the grinding box 2 for further crushing. Step 3: impurity removal and purification. After the battery is further crushed by the grinding box 2, the metal impurities in the raw materials are removed by chemical reaction. Then, the ferromagnetic metal impurities and impurity particles of different particle sizes are removed by magnetic separation, screening and filtering methods. Finally, the pH value of the solution is adjusted in stages to selectively precipitate impurities. Step 4: lithium precipitation and carbonization, adding the lithium sulfate solution prepared in step 3 to the sodium carbonate solution, maintaining appropriate stirring, so that the lithium ions and carbonate ions combine to form lithium carbonate precipitation, and after the reaction is completed, the lithium carbonate precipitation is separated from the mother liquor by centrifugation and filtration. The precipitate is washed, dried, etc. to obtain a lithium carbonate product, and then the recovered lithium carbonate is ground and dissolved in a solvent to form a lithium carbonate solution, and carbon dioxide gas is introduced into the lithium carbonate solution to react with lithium carbonate to generate lithium bicarbonate; Step 5: thermal decomposition and drying. The lithium bicarbonate solution generated in step 4 is thermally decomposed to decompose it into lithium carbonate, carbon dioxide and water. The lithium carbonate is separated from the solution by evaporation and crystallization. The lithium carbonate obtained after the thermal decomposition is dried to remove the water therein to obtain a purified lithium carbonate product.

[0033] In the present invention, when the user uses the device, two manipulators for picking up the placement frame 23 are preset on the front and rear sides of the device, and the batteries to be processed are neatly placed inside the placement frame 23 by the relevant automatic arrangement device, such as Figure 1 and Fig.10 As shown, the manipulator located at the rear of the device places the placement frame 23 with batteries placed inside on the top of the second movable frame 8, and with the help of two screw rods 25, the second movable frame 8 can be driven to move and adjust inside the first movable frame 7, so that the rear end of the second movable frame 8 moves forward, and drives one of the placement frames 23 on its top to move to a position on the same straight line as the crushing box 1, and at this time one of the placement frames 23 is located directly below the processing mechanism, and the front end of the second movable frame 8 moves outward from the inside of the first movable frame 7. The other placement frame 23 with batteries placed inside can be placed on the top of the second movable frame 8 in the extended state by the manipulator in front of the device, so that the batteries placed inside the other placement frame 23 are waiting for processing.

[0034] One of the placement frames 23 located below the processing mechanism can extend downward with the help of the telescopic ends of the two electric telescopic rods 12 of the processing mechanism, driving the mobile frame 6 and the two horizontal rotating plates 13 to squeeze the neatly arranged batteries inside one of the placement frames 23, so that the internal structure of the battery after the extrusion treatment is relatively loose, and the battery shell, plate and other components are initially deformed or damaged, making the subsequent crushing process easier to carry out. This can not only reduce the energy consumption of the crushing equipment, but also improve the crushing efficiency and shorten the processing time of the waste battery; and, during the extrusion process of the battery, the internal structure of the waste lithium iron phosphate battery will be deformed to a certain extent, which is helpful for the separation of impurities in the subsequent process. For example, the electrolyte, diaphragm and other components inside the battery may be more easily separated after extrusion, thereby facilitating subsequent recycling and processing; and, first extruding the battery can reduce the generation of dust to a certain extent, reducing the harm to the environment and human body; extruding the waste lithium iron phosphate battery before crushing can also improve the safety of the processing process. Since there may be residual electricity inside the battery, direct crushing may cause safety hazards such as short circuit and fire. The extrusion process first can reduce the amount of electricity and potential difference inside the battery to a certain extent, reducing safety hazards; Moreover, after the battery is placed inside the placement frame 23, due to the shallow depth inside the placement frame 23, part of the battery will be located outside the placement frame 23. When the mobile frame 6 and the two rotating plates 13 cooperate to squeeze the battery, the agglomerated impurities attached to the surface of the battery can also be squeezed and destroyed, and the two first sliders 14 can be used to move back and forth inside the corresponding first slide groove 4, and the mobile frame 6 and the two rotating plates 13 can be driven to move back and forth on the top of one of the placement frames 23 for adjustment. When squeezing the battery inside one of the placement frames 23, it also has the effect of rubbing the battery and driving multiple batteries to rotate inside the placement frame 23, so that the mobile frame 6 and the two rotating plates 13 can have a better squeezing effect on multiple batteries, and promote the impurities attached to the surface of some batteries to be effectively removed by friction; At the same time, in the process of squeezing and rubbing multiple batteries through the movable frame 6 and the two rotating plates 13, the external preset dust suction equipment can be controlled to start, so that the dust suction port 32 can automatically suck out and clean the impurities cleaned from the inside of the placement frame 23 at the same time, avoiding these cleaned impurities from entering the crushing box 1 together; and the dust suction port 32 can also suck out harmful gases that may exist in the battery squeezing process, avoiding the harmful gases from escaping in the processing environment and causing harm to the staff.

[0035] After squeezing multiple batteries inside one of the placement frames 23, the limit plate 31 at one end of the placement frame 23 close to the crushing box 1 can be controlled to rotate downward to a horizontal state, and the telescopic ends of the two electric telescopic rods 12 can be controlled to retract upward to return to their original position, driving the moving frame 6 and the two rotating plates 13 to move upward to the top of the second moving frame 8, and then the rotating plate 13 at the right end can be controlled to rotate downward to an inclined state, and with the help of the two first sliding blocks 14, it can be moved and adjusted toward the leftmost end inside the corresponding first sliding groove 4, and the rotating plate 13 after rotation adjustment can be driven to move to the left side of one of the placement frames 23, and then with the help of the telescopic ends of the two electric telescopic rods 12, one of the rotating plates 13 that rotate downward to an inclined state can be driven. The bottom end of the moving plate 13 moves to the inside of one of the placement frames 23, and as the two first sliders 14 move toward the right end inside the corresponding first chute 4, the rotating plate 13 in an inclined state is driven to push the extruded battery inside one of the placement frames 23 into the inside of the crushing box 1, and the battery is quickly crushed by the two crushing rollers 11. The battery after one crushing process will be discharged downward to the inside of the filter box 10, and the ductile metal material inside the crushed battery will be filtered and temporarily stored by the filter box 10, and the other parts can fall into the inside of the grinding box 2, and the relevant grinding mechanism provided inside the grinding box 2 will continue to grind and crush it to a finer state; After the grinding and crushing treatment in the grinding box 2, the powdered object after grinding and crushing is used to remove metal impurities therein by chemical reaction. For example, by adding reagents such as sodium hydroxide, the impurity ions can be separated from the solution in the form of precipitation, and then under appropriate conditions, the lithium ions and carbonate ions are reacted to form lithium carbonate precipitation. This process requires strict control of conditions such as temperature, reaction time and pH value to ensure the effect of lithium precipitation and product quality; then the lithium carbonate is converted into lithium bicarbonate through the carbonization step for subsequent thermal decomposition treatment. During the carbonization process, parameters such as temperature, reaction time and the amount of carbon dioxide introduced need to be controlled; finally, the lithium bicarbonate is thermally decomposed to generate lithium carbonate, carbon dioxide and water. This process requires control of the heating temperature and reaction time to ensure the full decomposition and crystallization of lithium carbonate; then the lithium carbonate obtained after thermal decomposition is dried to remove the moisture therein, and the lithium carbonate in the lithium iron carbonate battery can be obtained.

[0036] After the multiple batteries that have been squeezed in one of the placement frames 23 are pushed into the crushing box 1 with the help of the relevant parts of the processing mechanism, the processing mechanism can be controlled to move to the top of the crushing box 1, and then the two screw rods 25 can be controlled to drive the second moving frame 8 to move and reset inside the first moving frame 7, so that the other placement frame 23 placed at the top of the front end of the second moving frame 8 can be driven to move to the position on the same straight line as the crushing box 1. The manipulator located at the rear of the equipment removes one of the placement frames 23 placed at the top of the rear end of the second moving frame 8 and places a new placement frame 23, so as to ensure the continuous squeezing and crushing of the batteries. When multiple batteries enter the pulverizing box 1 for pulverization, the rotatable plate 13 can be controlled to rotate and reset to a horizontal state. Since the length and width of the movable frame 6 are adapted to the length and width of the interior of the pulverizing box 1, the telescopic ends of the two electric telescopic rods 12 can be controlled to extend downward together, driving the movable frame 6 and the two rotating plates 13 to move downward to the top of the pulverizing box 1, thereby sealing the top of the pulverizing box 1 to prevent battery components from splashing outward from the top of the pulverizing box 1 during the pulverizing process; and the exhaust port 33 can be controlled at the same time to discharge nitrogen into the interior of the pulverizing box 1 to control the oxygen concentration inside the pulverizing box 1 and prevent the generation of flammable volatile gases, thereby improving the safety of the battery pulverizing process.

[0037] If a large number of batteries enter the crushing box 1, after the movable frame 6 and the two rotating plates 13 move downward to the inside of the crushing box 1, the two rotating plates 13 can be controlled to rotate downward together, and the corresponding two second sliders 15 can be controlled to adaptively move and adjust in the second slide groove 16, so as to push the batteries on both sides of the crushing box 1 toward the middle, so that the two crushing rollers 11 can crush multiple batteries more quickly, and after the two rotating plates 13 rotate downward, the harmful gas and dust generated in the process of crushing the batteries can be sucked out with the help of the dust suction port 32, so as to ensure the safety of the batteries inside the crushing box 1 during the crushing process when the two rotating plates 13 do not block the top of the crushing box 1.

[0038] If the battery to be processed is a soft-pack battery, since its texture is softer than that of a hard-pack battery, after the battery is squeezed with the help of the processing mechanism, the telescopic mechanism can be controlled to drive the first moving frame 7 and other multiple components to move downward to the lowest position together, and then the two third sliders 20 can be controlled to move in the direction close to the first moving frame 7 inside the corresponding third slide groove 19, and after driving the filter box 10 to move to just below the first moving frame 7, a corresponding set of first sealing plates 29 inside the second moving frame 8 can be controlled to rotate downward and open, and then the two second sealing plates 30 inside the placement frame 23 at the top thereof can be controlled to rotate downward and open, so that the soft-pack battery after the squeezing process falls into the interior of the filter box 10, and then the two third sliders 20 are controlled to drive the filter box 10 to move to just above the grinding box 2, and then the bottom of the filter box 10 is controlled to rotate downward and open, so that the soft-pack battery after the squeezing process directly falls into the interior of the grinding box 2 for fine crushing and grinding processing, without the need to use the crushing box 1 to crush it once, thereby improving the crushing processing efficiency of such soft-pack batteries.

[0039] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A purification device for recovering lithium carbonate from lithium iron phosphate batteries, comprising a crushing box (1) and a grinding box (2), characterized in that: The grinding box (2) is arranged below the crushing box (1); two crushing rollers (11) are rotatably mounted inside the crushing box (1); a fixing frame (9) is mounted on the outer wall of the crushing box (1); a filter box (10) is arranged inside the fixing frame (9) and between the crushing box (1) and the grinding box (2); a first movable frame (7) is connected to the top of the fixing frame (9) via a telescopic mechanism; a second movable frame (8) is slidably mounted inside the first movable frame (7); two placement frames (23) for temporarily storing lithium iron phosphate batteries are placed above the second movable frame (8); and a processing mechanism for pre-processing a plurality of lithium iron phosphate batteries inside the placement frames (23) is arranged on the top of the crushing box (1).

2. A purification device for recovering lithium carbonate from lithium iron phosphate batteries according to claim 1, characterized in that: The processing mechanism comprises two brackets (3) installed on the top of the crushing box (1), the outer walls of the two brackets (3) on the sides close to each other are each provided with a first slide groove (4), the interiors of the two first slide grooves (4) are each provided with a first slider (14), and the ends of the two first sliders (14) away from the first slide groove (4) are jointly provided with a movable plate (5).

3. A purification device for recovering lithium carbonate from lithium iron phosphate batteries according to claim 2, characterized in that: The bottom end of the movable plate (5) is connected to a movable frame (6) via two electric telescopic rods (12); four inner walls of the movable frame (6) are provided with second slide grooves (16); second sliders (15) are installed inside the four second slide grooves (16); a rotating plate (13) is installed between two matching second sliders (15) for joint rotation; and the bottom ends of the two rotating plates (13) are respectively provided with a dust suction port (32) and an exhaust port (33).

4. A purification device for recovering lithium carbonate from lithium iron phosphate batteries according to claim 3, characterized in that: The telescopic mechanism comprises two first grooves (17) opened at the top of the fixing frame (9), double-headed screws (21) are rotatably mounted inside the two first grooves (17), two moving blocks (22) are threadedly mounted on the outer walls of the two double-headed screws (21), connecting rods (18) are rotatably mounted on the top ends of the two moving blocks (22), and the top ends of the two connecting rods (18) are hinged to the bottom end of the first moving frame (7).

5. A purification device for recovering lithium carbonate from lithium iron phosphate batteries according to claim 4, characterized in that: The two inner walls of the first movable frame (7) are each provided with a second groove (24), and screw rods (25) are rotatably mounted inside the two second grooves (24). Both ends of the second movable frame (8) are threadedly connected to the outer walls of the two screw rods (25), and two limit rods (26) are mounted on the top of the first movable frame (7) near the crushing box (1).

6. A purification device for recovering lithium carbonate from lithium iron phosphate batteries according to claim 5, characterized in that: A partition (27) is installed at the center of the top of the second movable frame (8), and electromagnets (28) are installed on the outer walls of the partition (27) on both sides away from each other. When the two electromagnets (28) are powered on, they are magnetically fixed to the placement frames (23) adjacent to them.

7. A purification device for recovering lithium carbonate from lithium iron phosphate batteries according to claim 6, characterized in that: Two sets of first sealing plates (29) are rotatably mounted inside the second movable frame (8), and the two sets of first sealing plates (29) are respectively located directly below the two placement frames (23).

8. A purification device for recovering lithium carbonate from lithium iron phosphate batteries according to claim 7, characterized in that: Two second sealing plates (30) are rotatably mounted inside the two placement frames (23), and a limiting plate (31) is rotatably mounted on one end of the two placement frames (23) close to the crushing box (1).

9. A purification device for recovering lithium carbonate from lithium iron phosphate batteries according to claim 8, characterized in that: The inner walls of both sides of the fixing frame (9) are provided with third slide grooves (19), and third sliding blocks (20) are installed inside the two third slide grooves (19). The ends of the two third sliding blocks (20) away from the third slide grooves (19) are connected to the filter box (10).

10. A purification process for recovering lithium carbonate from lithium iron phosphate batteries, characterized in that: The purification device according to claim 9 is included, and the purification process further comprises the following steps: Step 1: pre-processing the raw materials, using the telescopic ends of two electric telescopic rods (12) to extend downward, driving the mobile frame (6) and two rotating plates (13) to squeeze the neatly arranged batteries inside one of the placement frames (23); Step 2: crushing and screening, after squeezing the plurality of batteries in the placement frame (23), the two first sliders (14) of the control processing mechanism drive the rotating plate (13) to push the batteries in the placement frame (23) into the crushing box (1) for crushing, and the batteries after the crushing process are discharged downward to the inside of the filter box (10) for screening and filtering, and finally fall into the inside of the grinding box (2) for further crushing; Step 3: impurity removal and purification. After the battery is further crushed in the grinding box (2), the metal impurities in the raw material are removed by chemical reaction. Then, the ferromagnetic metal impurities and impurity particles of different sizes are removed by magnetic separation, screening and filtering methods. Finally, the pH value of the solution is adjusted in stages to selectively precipitate impurities. Step 4: lithium precipitation and carbonization, adding the lithium sulfate solution prepared in step 3 to the sodium carbonate solution, maintaining appropriate stirring, so that the lithium ions and carbonate ions combine to form lithium carbonate precipitation, and after the reaction is completed, the lithium carbonate precipitation is separated from the mother liquor by centrifugation and filtration. The precipitate is washed and dried to obtain a lithium carbonate product, and then the recovered lithium carbonate is ground and dissolved in a solvent to form a lithium carbonate solution, and carbon dioxide gas is introduced into the lithium carbonate solution to react with lithium carbonate to generate lithium bicarbonate; Step 5: thermal decomposition and drying. The lithium bicarbonate solution generated in step 4 is thermally decomposed to decompose it into lithium carbonate, carbon dioxide and water. The lithium carbonate is separated from the solution by evaporation and crystallization. The lithium carbonate obtained after the thermal decomposition is dried to remove the water therein to obtain a purified lithium carbonate product.

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