A waste battery recycling and lithium extraction process and device based on membrane separation technology

Abstract

The present invention relates to the technical field of waste battery recycling, specifically to a waste battery recycling and lithium extraction process and device based on membrane separation technology, comprising: a reverse osmosis shell assembly, the reverse osmosis shell assembly comprising a shell, a joint, a liquid inlet pipe, a concentrated water pipe and a liquid outlet pipe; a reverse osmosis assembly arranged in the reverse osmosis shell assembly, and the reverse osmosis assembly is used to preliminarily concentrate the slurry, and the reverse osmosis assembly comprises a liquid storage pipe, a pure water pipe and a cleaning pipe arranged inside the shell from left to right in sequence. In the present invention, after the anode slurry enters the liquid inlet pipe, it will enter the inside of the liquid storage pipe, and then the anode slurry will first pass through the filter belt and then pass through the water permeable pipe again to enter the reverse osmosis membrane, wherein when the anode slurry passes through the filter belt, the filter belt will play a role of pre-filtering the anode slurry, and the contact area between the anode slurry and the reverse osmosis membrane is larger, thereby improving the concentration efficiency, avoiding more impurities in the slurry, and affecting the service life and efficiency of the reverse osmosis membrane.

Description

Technical Field

[0001] The invention relates to the technical field of waste battery recycling, and in particular to a waste battery recycling and lithium extraction process and device based on membrane separation technology. Background Art

[0002] Lithium has many excellent physical and chemical properties, and its functions and uses are very extensive. It is considered to be an "energy metal that promotes world progress". Lithium products were originally used mainly in the military. With the rapid development of new energy, metallurgy, aerospace, glass manufacturing and other industries, people's demand for lithium has increased year by year, and the development of lithium extraction technology has also received increasing attention. With the popularization of electric vehicles and portable electronic devices, the number of waste lithium batteries in the world has increased rapidly. Therefore, the recycling of waste batteries is of great significance to the recycling of resources and environmental protection.

[0003] The principle of reverse osmosis technology is to separate these substances and water under the action of higher osmotic pressure than the solution, based on the fact that other substances cannot pass through the semipermeable membrane. The reverse osmosis membrane device generally adopts a roll-type structure. After the water enters the front end, the flow is diverted by rolling up the reverse osmosis membrane to obtain separated and purified product water and concentrated water with pollutants. The membrane pore size of the reverse osmosis membrane is very small, so it can effectively concentrate salts, colloids, microorganisms, organic matter, etc.

[0004] However, in actual use of the prior art, the water inlet at the front end of the reverse osmosis membrane device is very obviously reduced in permeability due to end face blockage after long-term use, which greatly reduces the service life and efficiency of the reverse osmosis membrane device. Summary of the invention

[0005] The purpose of the present invention is to provide a waste battery recycling and lithium extraction process and device based on membrane separation technology to solve the problem that the permeability is significantly reduced due to end face blockage, which greatly reduces the service life and efficiency of the reverse osmosis membrane device.

[0006] To achieve the above object, the present invention provides the following technical solution: a device for recycling and extracting lithium from waste batteries based on membrane separation technology, comprising:

[0007] A reverse osmosis shell assembly, comprising a shell, a joint, a liquid inlet pipe, a concentrated water pipe and a liquid outlet pipe;

[0008] A reverse osmosis assembly is arranged in a reverse osmosis shell assembly, and the reverse osmosis assembly is used for preliminary concentration of slurry. The reverse osmosis assembly includes a liquid storage pipe, a pure water pipe and a clean pipe which are arranged in sequence from left to right inside the shell. The pure water pipe is fixedly connected to one end of the liquid storage pipe, and the pure water pipe is fixedly penetrated through the clean pipe and is connected to the concentrated water pipe. Four reverse osmosis membranes are fixedly embedded in the surface of the pure water pipe. Four permeable pipes are fixedly embedded in the middle of the side walls at relative positions of the liquid storage pipe and the clean pipe, and the inside of the permeable pipes is respectively connected to the inside of the liquid storage pipe and the clean pipe. The reverse osmosis membranes are spirally wound on the surfaces of the pure water pipe and the permeable pipe respectively. A guide frame is fixedly connected to the inner wall of the permeable pipe, and a filter belt for pre-filtering anode slurry is movably connected to the surface of the guide frame. A plurality of connecting pipes are fixedly embedded in the middle of the clean pipe, and the connecting pipes are connected to the inside of the liquid outlet pipe.

[0009] A cleaning component is arranged in the reverse osmosis shell component and is used to clean impurities in the cleaning pipe.

[0010] Preferably, the joint is threadedly connected to one end of the opening position of the shell, and a liquid inlet pipe is fixedly connected to the middle part of the joint. The liquid storage pipe and the cleaning pipe are tightly fitted on the inner wall of the shell, and a through hole is provided at the end of the liquid storage pipe corresponding to the liquid inlet pipe position so that the interior of the liquid inlet pipe is connected with the interior of the liquid storage pipe. The concentrated water pipe and the liquid outlet pipe are respectively fixedly embedded in the end of the shell away from the joint position, and the interior of the liquid outlet pipe is connected with the interior of the shell. A connecting pipe is fixedly provided on the inner wall of the end of the shell away from the joint position, and the pure water pipe is movably inserted into the inner wall of the connecting pipe, and the interior of the connecting pipe is respectively connected with the interiors of the pure water pipe and the concentrated water pipe, a positioning pipe is fixedly connected to the surface of the pure water pipe corresponding to the connecting pipe position, and the positioning pipe is movably sleeved on the surface of the connecting pipe, and a notch is provided at one end of the positioning pipe corresponding to the concentrated water pipe position, so that the notch at one end of the positioning pipe cooperates with the concentrated water pipe to position the direction of the cleaning pipe.

[0011] Preferably, a plurality of holes are provided in the middle of one end of the water permeable pipe away from the cleaning pipe position, and the position of the holes in the middle of the water permeable pipe corresponds to the position of the filter belt, so that the anode slurry inside the water permeable pipe first passes through the filter belt and enters the position between the reverse osmosis membrane and the outer shell from the holes in the middle of the water permeable pipe, and a locking edge is fixedly connected to the surface of the guide frame corresponding to the position of the filter belt, and the locking edge is tightly fitted to the two ends of the filter belt, so that the guide frame cooperates with the locking edge to fit the filter belt to the inner wall of the water permeable pipe, and one end of the cleaning pipe corresponding to the position of the liquid storage pipe is fixedly connected to a liquid inlet grid, and the reverse osmosis membrane is located between the liquid storage pipe and the liquid inlet grid, so that the liquid passing through the reverse osmosis membrane enters the inside of the connecting pipe through the liquid inlet grid and is discharged from the liquid outlet pipe.

[0012] Preferably, the cleaning component includes a support frame fixedly connected to the surface of the pure water pipe through a bracket, and the support frame is an annular structure, the support frame is located inside the cleaning pipe, the filter belt is movably wound on the surface of the support frame, the surface of the pure water pipe corresponding to the position of the cleaning pipe is fixedly connected with a fixing frame, one end of the fixing frame corresponding to the position of the filter belt is rotatably connected to a driving roller for driving the filter belt through a bearing, and the filter belt is tightly fitted between the driving roller and the fixing frame, and a brush is provided at one end of the fixing frame away from the driving roller position, and the brush is tightly fitted to the inner wall of the filter belt, so that impurities on the inner wall of the filter belt can be cleaned by the brush when the filter belt is transmitted.

[0013] Preferably, one end of the driving roller output shaft is fixedly connected to a bevel gear, the surface of the bevel gear is meshed with a bevel gear ring, the surface of the bevel gear is meshed with a driving gear, and the driving gear is eccentrically arranged to the bevel gear ring, a drain pipe is fixedly embedded in the bottom of one end of the outer shell away from the joint position, and a control valve is provided in the middle of the drain pipe, and a drain port is opened at one end of the cleaning pipe corresponding to the drain pipe position, so that impurities inside the cleaning pipe can be discharged outward through the drain port and the drain pipe.

[0014] Preferably, a groove is provided on the surface of the shell corresponding to the driving gear position so that the driving gear can mesh with the helical gear ring, and a second guide ring is fixedly connected to the surface of the shell corresponding to the driving gear position, and the second guide ring is rotatably connected to the inner wall of the driving gear so that the second guide ring can limit the driving gear, and sealing grooves are respectively provided at both ends of the helical gear ring, and the inner wall of the sealing groove is rotatably connected to the first guide ring, and the first guide ring is fixedly connected to the inner wall of the cleaning tube so that the first guide ring cooperates with the sealing groove to limit the helical gear ring while preventing liquid from leaking from the connection between the helical gear ring and the driving gear.

[0015] The present invention also provides a process for recycling and extracting lithium from waste batteries using a membrane separation technology, comprising the following steps:

[0016] S1. Prepare cathode slurry: take one or more metal compound solutions and conductive polymers, add deionized water to prepare cathode slurry, wherein the metal compound solution and the conductive polymer include but are not limited to one or a mixture of nickel sulfate solution, cobalt sulfate solution, lithium sulfate solution, manganese sulfate solution, nickel chloride solution and polyaniline solution;

[0017] S2. Prepare anode slurry: take waste battery powder and add deionized water to prepare anode slurry;

[0018] S3, electrolysis reaction: circulating the cathode slurry prepared in step S1 into the cathode chamber of the electrolytic cell, continuously passing the anode powder slurry prepared in step S2 into the anode chamber of the electrolytic cell, connecting to a power source, wherein the cathode chamber and the anode chamber of the electrolytic cell are separated by an anion membrane so that lithium ions do not pass through the diaphragm, and at the same time, replenishing the cathode slurry into the cathode chamber and recovering the electrolysis product to ensure the stability of the current;

[0019] S4, filter pressing: passing the anode slurry after electrolysis in step S3 into a filter press to separate the lithium-containing solution and the solid residue, passing the lithium-containing solution into a microporous filter for purification to remove insoluble impurities;

[0020] S5, step-by-step concentration: the lithium-containing solution refined in step S4 is passed into a reverse osmosis shell assembly for preliminary concentration, and then the lithium-containing solution concentrated by the reverse osmosis membrane is passed into an electrodialysis device to further increase the concentration of lithium in the lithium-containing solution. At the same time, the deionized water produced by the reverse osmosis is used to prepare the anode slurry in step S2 and is reserved for standby use. The fresh water produced by the electrodialysis is returned to the reverse osmosis shell assembly for reuse. No wastewater is discharged during the entire concentration process;

[0021] S6, lithium precipitation reaction: adding sodium carbonate solution to the lithium-containing solution concentrated in step S5, and preparing lithium carbonate slurry by reaction, wherein the molar ratio of lithium element to sodium carbonate is 1:0.5-0.8, and the reaction time is 30-120 minutes;

[0022] S7, obtaining a battery-grade lithium carbonate product: passing the lithium carbonate slurry in step S6 into a centrifuge for high-speed separation and dehydration to obtain a lithium carbonate wet material, and washing the dehydrated lithium carbonate wet material with washing water, while recovering the washed solution, and then dehydrating and drying, air flow crushing, demagnetizing and packaging the lithium carbonate wet material after centrifugal washing in turn to obtain a battery-grade lithium carbonate product.

[0023] Preferably, the waste battery powder in step S2 includes but is not limited to one or a mixture of lithium iron phosphate battery powder, ternary battery powder, lithium cobalt oxide battery powder, lithium manganese oxide battery powder, lithium iron manganese phosphate battery powder and solid-state battery powder, and the solid-liquid ratio of the anode slurry in step S2 ranges from 10% to 20%, the electrolysis products recovered in step S3 include but are not limited to hydrogen, metallic copper and metallic nickel, the dehydrated lithium carbonate wet material in step S7 is washed 1 to 3 times with washing water, and the washed solution recovered in step S7 is used for the preparation of the sodium carbonate solution in step S6, and the washing water in step S7 includes but is not limited to one or a mixture of two of the deionized water and pure water reserved for standby in step S5.

[0024] Preferably, the specific steps of recovering the washed solution in step S7 include:

[0025] S11, decarbonization and value adjustment: adding an acidic regulator to the solution of the non-lithium carbonate wet material separated after centrifugation in step S7, adjusting the pH to 2-4, and then adding an alkaline regulator to adjust the pH to 7-9 to obtain a value adjustment solution, so that the solution of the non-lithium carbonate wet material separated after centrifugation in S7 is subjected to lithium extraction again, thereby improving the recovery rate of lithium and recovering by-products at the same time;

[0026] S12, MVR evaporation and desalination: the adjusted solution in step S11 is passed into MVR for evaporation and concentration to obtain by-product industrial salt, and the concentrated solution is processed again by steps S6 and S7, wherein the deionized water produced by MVR is reused in step S2 for preparing anode slurry.

[0027] Preferably, the acidic regulator in step S11 includes but is not limited to one or a mixture of hydrochloric acid, sulfuric acid, nitric acid and phosphoric acid, the alkaline regulator in step S11 includes but is not limited to one or a mixture of sodium hydroxide and lithium hydroxide, and the industrial salt in step S12 includes but is not limited to one or a mixture of sodium chloride, sodium sulfate, sodium nitrate and sodium phosphate.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. After the anode slurry enters the liquid inlet pipe, it will enter the interior of the liquid storage pipe. After that, the anode slurry will first pass through the filter belt and then pass through the water-permeable pipe again to enter the reverse osmosis membrane. When the anode slurry passes through the filter belt, the filter belt will pre-filter the anode slurry to prevent the slurry from being contaminated by impurities and affecting the service life of the reverse osmosis membrane. Since the anode slurry passes through the water-permeable pipe and comes out, and the water-permeable pipe is located in the middle of the reverse osmosis membrane winding structure, the anode slurry can pass through the periphery of the reverse osmosis membrane or the inner ring of the reverse osmosis membrane, and the contact area between the anode slurry and the reverse osmosis membrane is larger, so that the anode slurry is dispersed and enters the position in the reverse osmosis membrane, thereby accelerating the concentration. 2. The present invention also drives the driving gear to rotate, so that the driving gear drives the helical gear ring to rotate, and the helical gear ring cooperates with the helical bevel gear and the driving roller to drive the filter belt transmission, so that the filter The inner wall of the belt and the brush on the surface of the fixed frame move relative to each other, and then the brush cleans the impurities attached to the inner wall of the filter belt due to filtration, so that the impurities cleaned from the inside of the cleaning tube will settle inside the cleaning tube until it needs to be discharged. By opening the control valve of the drain pipe, the liquid inside the cleaning tube is discharged outward through the drain hole at the bottom of the cleaning tube and the drain pipe, thereby achieving the purpose of pre-filtering the slurry through the filter belt and cleaning the filter belt; 3. The present invention also optimizes the production process by electrochemical lithium extraction, reduces unnecessary steps and material waste, thereby improving production efficiency. At the same time, through more precise process control and resource recovery, it improves resource utilization and reduces production costs. The optimized production process reduces the discharge of wastewater and waste, reduces the negative impact on the environment, and further reduces environmental pollution and resource consumption through the recovery and reuse of by-products and waste. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic diagram of the overall structure of a waste battery recycling and lithium extraction process device based on membrane separation technology of the present invention;

[0030] Figure 2 This is an exploded view of the overall structure of a waste battery recycling and lithium extraction process device based on membrane separation technology of the present invention;

[0031] Figure 3 This is a cross-sectional view of the overall structure of a waste battery recycling and lithium extraction process device based on membrane separation technology of the present invention Figure 1 ;

[0032] Figure 4 This is a cross-sectional view of the overall structure of a waste battery recycling and lithium extraction process device based on membrane separation technology of the present invention Figure 2 ;

[0033] Figure 5This is a schematic diagram of the reverse osmosis component structure of a waste battery recycling and lithium extraction process device based on membrane separation technology of the present invention;

[0034] Figure 6 This is an exploded diagram of the reverse osmosis component structure of a waste battery recycling and lithium extraction process device based on membrane separation technology of the present invention;

[0035] Figure 7 It is a partial cross-sectional view of the reverse osmosis component structure of a waste battery recycling and lithium extraction process device based on membrane separation technology of the present invention;

[0036] Figure 8 It is a side cross-sectional view of the reverse osmosis component structure of a waste battery recycling and lithium extraction process device based on membrane separation technology of the present invention;

[0037] Fig. 9 This is a schematic diagram of the structure of a cleaning component of a waste battery recycling and lithium extraction process device based on membrane separation technology of the present invention;

[0038] Fig.10 This is an overall flow chart of a waste battery recycling and lithium extraction process based on membrane separation technology of the present invention;

[0039] Fig.11 This is a line graph showing changes in solution lithium concentration during an electrolysis process of a waste battery recycling and lithium extraction process based on membrane separation technology according to the present invention.

[0040] In the figure: 101, housing; 102, joint; 103, liquid inlet pipe; 104, connecting pipe; 105, concentrated water pipe; 106, liquid outlet pipe;

[0041] 201, liquid storage pipe; 202, pure water pipe; 203, cleaning pipe; 204, reverse osmosis membrane; 205, water permeable pipe; 206, guide frame; 207, filter belt; 208, positioning pipe; 209, liquid inlet grid; 210, connecting pipe;

[0042] 301, support frame; 302, fixed frame; 303, driving roller; 304, bevel gear; 305, bevel gear ring; 306, first guide ring; 307, driving gear; 308, second guide ring; 309, sewage pipe. DETAILED DESCRIPTION

[0043] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not 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.

[0044] Embodiment 1

[0045] See also Figure 1-9 The present invention provides a device for recycling and extracting lithium from waste batteries based on membrane separation technology, comprising:

[0046] The reverse osmosis shell assembly includes a shell 101, a joint 102, a liquid inlet pipe 103, a concentrated water pipe 105 and a liquid outlet pipe 106;

[0047] A reverse osmosis assembly is arranged in a reverse osmosis shell assembly, and the reverse osmosis assembly is used for preliminary concentration of the slurry. The reverse osmosis assembly includes a liquid storage pipe 201, a pure water pipe 202 and a clean pipe 203 which are arranged in sequence from left to right inside the shell 101. The pure water pipe 202 is fixedly installed at one end of the liquid storage pipe 201, and the pure water pipe 202 is fixedly penetrated through the clean pipe 203 and is connected to the concentrated water pipe 105. Four reverse osmosis membranes 204 are fixedly embedded in the surface of the pure water pipe 202. Four permeable pipes 205 are fixedly embedded in the middle of the side walls at relative positions of the liquid storage pipe 201 and the clean pipe 203, and the interiors of the permeable pipes 205 are respectively connected to the interiors of the liquid storage pipe 201 and the clean pipe 203. The reverse osmosis membranes 204 are spirally wound around the pure water pipe 202 and the permeable pipe 205. A guide frame 206 is fixedly installed on the surface of the water pipe 205 and the inner wall of the water-permeable pipe 205. A filter belt 207 for pre-filtering the anode slurry is movably connected to the surface of the guide frame 206. A plurality of connecting pipes 210 are fixedly embedded in the middle of the cleaning pipe 203, and the connecting pipe 210 is connected to the inside of the liquid outlet pipe 106. The joint 102 is threadedly connected to one end of the opening position of the shell 101. A liquid inlet pipe 103 is fixedly installed in the middle of the joint 102. The liquid storage pipe 201 and the cleaning pipe 203 are tightly fitted on the inner wall of the shell 101. A through hole is opened at one end of the liquid storage pipe 201 corresponding to the position of the liquid inlet pipe 103, so that the inside of the liquid inlet pipe 103 is connected to the inside of the liquid storage pipe 201. The concentrated water pipe 105 and the liquid outlet pipe 106 are respectively fixedly embedded in At one end of the shell 101 away from the joint 102, the interior of the liquid outlet pipe 106 is connected to the interior of the shell 101, and a connecting pipe 104 is fixedly provided on the inner wall of the end of the shell 101 away from the joint 102. The pure water pipe 202 is movably inserted into the inner wall of the connecting pipe 104, and the interior of the connecting pipe 104 is respectively connected to the interiors of the pure water pipe 202 and the concentrated water pipe 105. A positioning pipe 208 is fixedly installed on the surface of the pure water pipe 202 corresponding to the position of the connecting pipe 104, and the positioning pipe 208 is movably sleeved on the surface of the connecting pipe 104, and a notch is opened at one end of the positioning pipe 208 corresponding to the position of the concentrated water pipe 105, so that the notch at one end of the positioning pipe 208 cooperates with the concentrated water pipe 105 to position the direction of the cleaning pipe 203, and the permeable pipe 2 05 is provided with a plurality of holes in the middle of one end away from the cleaning pipe 203, and the position of the holes in the middle of the water-permeable pipe 205 corresponds to the position of the filter belt 207, so that the anode slurry inside the water-permeable pipe 205 first passes through the filter belt 207 and enters the position between the reverse osmosis membrane 204 and the shell 101 from the holes in the middle of the water-permeable pipe 205. A locking edge is fixedly installed on the surface of the guide frame 206 corresponding to the position of the filter belt 207, and the locking edge is tightly fitted with both ends of the filter belt 207, so that the guide frame 206 cooperates with the locking edge to fit the filter belt 207 to the inner wall of the water-permeable pipe 205. A liquid inlet grille 209 is fixedly installed at one end of the cleaning pipe 203 corresponding to the position of the liquid storage pipe 201, and the reverse osmosis membrane 204 is located between the liquid storage pipe 201 and the liquid inlet grille 209.So that the liquid passing through the reverse osmosis membrane 204 enters the interior of the connecting pipe 210 through the liquid inlet grid 209 and is discharged from the liquid outlet pipe 106;

[0048] When the above structure is in use, the anode slurry enters the interior of the liquid storage tube 201 through the liquid inlet pipe 103, passes through the filter belt 207, and then passes through the water permeable pipe 205 to enter the reverse osmosis membrane 204. When the anode slurry passes through the filter belt 207, the filter belt 207 will pre-filter the anode slurry to prevent the slurry from being filled with impurities, which will affect the service life of the reverse osmosis membrane 204. Since the anode slurry passes through the water permeable pipe 205, the water permeable pipe 205 is located in the middle of the winding structure of the reverse osmosis membrane 204, dispersing the anode slurry into the reverse osmosis membrane 204, and playing a role in For the purpose of accelerating concentration, a plurality of holes are provided in the middle of one end of the water permeable pipe 205 away from the clean pipe 203, that is, there is no hole at the end of the water permeable pipe 205 corresponding to the clean pipe 203. This requires the solution to finally pass through a part of the reverse osmosis membrane 204 horizontally, so as to further achieve the purpose of thorough concentration. The separated concentrated water will pass through the liquid inlet grid 209, the connecting pipe 210 and the outer shell 101, and finally be discharged through the liquid outlet pipe 106, wherein the pure water passes through the reverse osmosis membrane 204 into the pure water pipe 202, and then into the connecting pipe 104, and finally is discharged outward through the concentrated water pipe 105.

[0049] A cleaning component is arranged in the reverse osmosis shell component and is used to clean impurities in the cleaning pipe 203. The cleaning component includes a support frame 301 fixedly installed on the surface of the pure water pipe 202 through a bracket, and the support frame 301 is an annular structure. The support frame 301 is located inside the cleaning pipe 203, and the filter belt 207 is movably wound on the surface of the support frame 301. The surface of the pure water pipe 202 corresponding to the position of the cleaning pipe 203 is fixedly installed with a fixing frame 302, and one end of the fixing frame 302 corresponding to the position of the filter belt 207 is rotatably connected to a driving filter belt 207 through a bearing. 07 is driven by a driving roller 303, and the filter belt 207 is tightly fitted between the driving roller 303 and the fixing frame 302. A brush is provided at one end of the fixing frame 302 away from the driving roller 303, and the brush is tightly fitted to the inner wall of the filter belt 207, so that the impurities on the inner wall of the filter belt 207 can be cleaned by the brush when the filter belt 207 is driven. A bevel gear 304 is fixedly installed at one end of the output shaft of the driving roller 303, and a bevel gear ring 305 is meshed on the surface of the bevel gear 304, and a driving gear 307 is meshed on the surface of the bevel gear ring 305, and the driving gear 307 is eccentrically arranged with the bevel gear ring 305, a sewage pipe 309 is fixedly embedded in the bottom of the end of the housing 101 away from the joint 102, and a control valve is provided in the middle of the sewage pipe 309, and a sewage outlet is provided at one end of the cleaning pipe 203 corresponding to the sewage pipe 309, so that impurities inside the cleaning pipe 203 can be discharged outward through the sewage outlet and the sewage pipe 309, and a groove is provided on the surface of the housing 101 corresponding to the driving gear 307 so that the driving gear 307 is meshed with the bevel gear ring 305, and the housing 101 corresponding to the driving gear 307 is provided with a A second guide ring 308 is fixedly installed on the surface, and the second guide ring 308 is rotatably connected to the inner wall of the driving gear 307, so that the second guide ring 308 has a limiting effect on the driving gear 307. Both ends of the helical gear ring 305 are respectively provided with sealing grooves, and the inner wall of the sealing groove is rotatably connected to the first guide ring 306, and the first guide ring 306 is fixedly installed on the inner wall of the cleaning tube 203, so that the first guide ring 306 cooperates with the sealing groove to limit the helical gear ring 305 while preventing liquid from leaking from the connection between the helical gear ring 305 and the driving gear 307;

[0050] When the above structure is in use, the driving gear 307 drives the bevel gear ring 305 to rotate, so that the bevel gear ring 305 drives the filter belt 207 through the bevel gear 304 and the driving roller 303, so that the inner wall of the filter belt 207 and the brush on the surface of the fixed frame 302 move relative to each other, and then the impurities attached to the inner wall of the filter belt 207 due to filtration are cleaned by the brush. When it needs to be discharged, the control valve of the drain pipe 309 is opened, so that the liquid inside the cleaning pipe 203 is discharged outward through the drain hole at the bottom of the cleaning pipe 203 and the drain pipe 309, thereby achieving the purpose of pre-filtering the slurry through the filter belt 207 and cleaning the filter belt 207.

[0051] Working principle: When using the device, the invention firstly winds four reverse osmosis membranes 204 in one direction on the surface of the pure water pipe 202 for two turns, then passes the reverse osmosis membrane 204 through two adjacent permeable pipes 205, and continues to wind the remaining part of the reverse osmosis membrane 204 on the surface of the permeable pipe 205, so that the reverse osmosis membrane 204 fits tightly on the surfaces of the pure water pipe 202 and the permeable pipe 205 and reduces the gap between the two parts, and then according to the notch position at one end of the positioning pipe 208 corresponding to the position of the concentrated water pipe 105, the clean pipe 203, the pure water pipe 202, the liquid storage pipe 201 and the reverse osmosis membrane 204 are inserted into the shell 101, and the joint 102 and the shell 101 are screwed and tightened, and the whole device is installed;

[0052] By setting up a reverse osmosis component, in which the liquid inlet pipe 103 is used to connect the anode slurry, the anode slurry will enter the interior of the liquid storage pipe 201 and the interior of the water permeable pipe 205 after entering the liquid inlet pipe 103. Since a plurality of holes are opened in the middle of one end of the water permeable pipe 205 away from the cleaning pipe 203, and the filter belt 207 is attached to the inner wall of the water permeable pipe 205, the anode slurry inside the water permeable pipe 205 will first pass through the filter belt 207 and then pass through the water permeable pipe 205 again to enter the reverse osmosis membrane 204. When the anode slurry passes through the filter belt 207, the filter belt 207 will pre-filter the anode slurry to prevent a large amount of impurities in the slurry from affecting the service life of the reverse osmosis membrane 204. Since the anode slurry passes through the inside of the water permeable pipe 205 and comes out, and the water permeable pipe 205 is located in the middle of the winding structure of the reverse osmosis membrane 204, the anode slurry can pass through the periphery of the reverse osmosis membrane 204 or the inner circle of the reverse osmosis membrane 204, so that the dispersed anode slurry can be The anode slurry enters the position inside the reverse osmosis membrane 204, which serves the purpose of accelerating concentration. Compared with the method of penetrating the reverse osmosis membrane 204 through one end in the prior art, the contact area between the anode slurry and the reverse osmosis membrane 204 is larger, thereby improving the concentration efficiency. In addition, since a plurality of holes are provided in the middle of one end of the water permeable pipe 205 away from the position of the cleaning pipe 203, that is, there are no holes at the end of the water permeable pipe 205 corresponding to the position of the cleaning pipe 203, this requires that the solution finally needs to horizontally penetrate a part of the reverse osmosis membrane 204, further achieving the purpose of thorough concentration. The separated concentrated water will enter the connecting pipe 210 through the liquid inlet grid 209, and enter the part of the housing 101 away from the joint 102 through the connecting pipe 210, and finally be discharged through the liquid outlet pipe 106. The flow path of the pure water part is that the pure water enters the inside of the pure water pipe 202 through the reverse osmosis membrane 204, and enters the inside of the connecting pipe 104 through the pure water pipe 202, and finally is discharged outward through the concentrated water pipe 105.

[0053] When the filter belt 207 needs to be cleaned, the drive gear 307 can be driven to rotate manually or by an external drive electrical appliance, so that the drive gear 307 drives the bevel gear ring 305 to rotate, and when the bevel gear ring 305 rotates, the bevel gear ring 305 drives the bevel gear 304 to rotate, and then the bevel gear 304 drives the drive roller 303 to rotate and drive the filter belt 207 to drive, and when the filter belt 207 drives, the inner wall of the filter belt 207 and the brush on the surface of the fixing frame 302 move relative to each other, and then the inner wall of the filter belt 207 is cleaned by the brush. The impurities attached to the filter are cleaned, wherein since the cleaning pipe 203 is not directly connected to the concentrated water pipe 105 or the liquid outlet pipe 106, the solution inside the cleaning pipe 203 is almost static, that is, the impurities cleaned from the cleaning pipe 203 will settle inside the cleaning pipe 203 until it needs to be discharged. By opening the control valve of the drain pipe 309, the liquid inside the cleaning pipe 203 is discharged outward through the drain hole at the bottom of the cleaning pipe 203 and the drain pipe 309, thereby achieving the purpose of pre-filtering the slurry through the filter belt 207 and cleaning the filter belt 207.

[0054] See also Figure 10-11 The present invention also provides a process for recycling and extracting lithium from waste batteries using a membrane separation technology, comprising the following steps:

[0055] S1. preparing cathode slurry: taking lithium sulfate solution and adding deionized water to prepare cathode slurry;

[0056] S2. Prepare anode slurry: Take waste lithium iron phosphate battery powder and add deionized water to prepare anode slurry with a solid-liquid ratio of 10%;

[0057] S3, electrolytic reaction: circulating the cathode slurry prepared in step S1 into the cathode chamber of the electrolytic cell, continuously passing the anode powder slurry prepared in step S2 into the anode chamber of the electrolytic cell, and connecting to a power supply to achieve continuous lithium extraction, wherein the cathode chamber and the anode chamber of the electrolytic cell are separated by an anion membrane so that lithium ions do not pass through the diaphragm, thereby improving the efficiency of lithium recovery, and at the same time replenishing the cathode slurry into the cathode chamber and recovering the electrolysis product, and maintaining the pH value of the cathode slurry stable, thereby ensuring the stability of the current, wherein the recovered electrolysis products include but are not limited to hydrogen, metallic copper and metallic nickel, and at the same time, the hydrogen generated by the cathode reaction is used for boiler combustion to generate heating medium water vapor, which makes the by-products pollution-free and can be effectively utilized, turning waste into treasure;

[0058] The ion reaction formula generated in step S3 is:

[0059] ;

[0060] S4, filter pressing: passing the anode slurry after electrolysis in step S3 into a filter press to separate the lithium-containing solution and the solid residue, passing the lithium-containing solution into a microporous filter for refining to remove insoluble impurities, wherein the solid residue is washed and purified to obtain the corresponding precursor product;

[0061] S5, step-by-step concentration: the lithium-containing solution refined in step S4 is passed into a reverse osmosis shell assembly for preliminary concentration, and then the lithium-containing solution concentrated by the reverse osmosis membrane is passed into an electrodialysis device to further increase the concentration of lithium in the lithium-containing solution. At the same time, the deionized water produced by the reverse osmosis is used to prepare the anode slurry in step S2 and is reserved for standby use. The fresh water produced by the electrodialysis is returned to the reverse osmosis shell assembly for reuse. No wastewater is discharged during the entire concentration process;

[0062] S6, lithium precipitation reaction: adding sodium carbonate solution to the lithium-containing solution concentrated in step S5, and preparing lithium carbonate slurry by reaction, wherein the molar ratio of lithium element to sodium carbonate is 1:0.5-0.8, and the reaction time is 30-120 minutes;

[0063] The ion reaction formula in step S6 is:

[0064] ;

[0065] S7, obtaining a battery-grade lithium carbonate product: passing the lithium carbonate slurry in step S6 into a centrifuge for high-speed separation and dehydration to obtain a lithium carbonate wet material, and washing the dehydrated lithium carbonate wet material with washing water for 1 to 3 times, and recovering the washed solution at the same time, wherein the washing water comprises one or a mixture of condensed water and deionized water produced in step S5, and newly added deionized water from the outside, and the recovered washed solution is used for the preparation of the sodium carbonate solution in step S5, and the lithium carbonate wet material after centrifugal washing is successively dehydrated and dried, air flow crushed, demagnetized and packaged to obtain a battery-grade lithium carbonate product;

[0066] The specific steps of recovering the washed solution in step S7 include:

[0067] S11, decarbonization and value adjustment: adding sulfuric acid to the solution of the non-lithium carbonate wet material separated after centrifugation in step S7, adjusting the pH to 2-4, and then adding one or a mixture of sodium hydroxide and lithium hydroxide to adjust the pH to 7-9 to prepare a value adjustment solution, so that the solution of the non-lithium carbonate wet material separated after centrifugation in S7 is subjected to lithium extraction again, thereby improving the recovery rate of lithium and recovering by-products;

[0068] S12: MVR evaporation and desalination: the adjusted solution in step S11 is passed into the MVR for evaporation and concentration to obtain industrial salt, wherein the industrial salt is sodium sulfate, and the concentrated solution is processed again by steps S6 and S7, wherein the deionized water produced by the MVR is reused in step S2 for preparing anode slurry;

[0069] The concentration change of the lithium solution during the electrolysis process of Example 1 is as follows: Fig.11 shown.

[0070] Embodiment 2

[0071] The difference from the first embodiment is that:

[0072] S2. Prepare anode slurry: Take waste ternary battery powder and add deionized water to prepare anode slurry with a solid-liquid ratio of 20%.

[0073] Embodiment 3

[0074] The difference from the first embodiment is that:

[0075] S2. Prepare anode slurry: Prepare anode slurry: Take waste ternary battery powder, waste lithium iron phosphate battery powder and waste lithium cobalt oxide battery powder in a mass ratio of 1:1:1, mix them and add deionized water to prepare anode slurry with a solid-liquid ratio of 10%.

[0076] The lithium extraction effects of each embodiment are shown in Table 1 and Table 2:

[0077] Table 1: Electrolysis effects of different waste battery raw materials

[0078]

[0079] Table 2: The composition of the solution after electrolysis of different waste battery raw materials of the same mass

[0080]

[0081] It can be clearly seen from Tables 1 and 2 that the electrochemical method adopted by the present invention can achieve preferential and selective lithium extraction with a selectivity of up to 99%. At the same time, the electrochemical process can be used for different compositions of waste battery raw materials without affecting the electrolysis efficiency.

[0082] The present invention also provides the following two comparative examples:

[0083] Comparative Example 1

[0084] The difference from the first embodiment is that:

[0085] S3. Electrolysis reaction: The hydrogen produced by the cathode reaction is not used for boiler combustion, and the different effects produced are shown in Table 3 below:

[0086] Table 3: Steam volume required to synthesize 1 ton of lithium carbonate

[0087]

[0088] It can be seen that the by-product hydrogen produced by the electrochemical process of the present invention can save 85% of steam consumption by preparing steam through boiler combustion.

[0089] Comparative Example 2

[0090] The difference from the first embodiment is that:

[0091] S4, filter pressing: adding an acid and alkali reagent to the anode slurry after electrolysis in step S3 to remove impurities, and then passing it into a filter press to separate the lithium-containing solution and the solid residue, passing the lithium-containing solution into a microporous filter for purification to remove insoluble impurities, wherein the solid residue is washed and purified to obtain the corresponding precursor product;

[0092] S5, MVR concentration: The lithium-containing solution after the refinement in step S4 is passed into the MVR equipment for concentration, and the different effects produced thereby are shown in the following Table 4:

[0093] Table 4: Usage of different concentration methods

[0094]

[0095] It can be seen that the conventional MVR equipment is used to concentrate the lithium-containing solution, and the power source is not single, and more requirements are high in cost, and the maintenance cycle is short. However, the technical solution recorded in the first embodiment of the present invention is obviously better than the existing MVR lithium concentration and extraction process, which has a single power source, lower operating environment requirements, long maintenance cycle and low cost, and can achieve greater economic benefits while achieving low-cost lithium extraction.

[0096] The present invention optimizes the production process of recycling and extracting lithium from waste batteries through electrochemical lithium extraction, reduces unnecessary steps and material waste, and this optimization not only improves production efficiency and shortens production cycle, but also reduces production costs and enhances the market competitiveness of enterprises.

[0097] The present invention improves resource utilization through more precise process control and resource recovery. In key steps such as electrolytic reaction, filter pressing, step-by-step concentration, and lithium precipitation reaction, efficient separation and purification technologies are used to ensure the recovery rate and purity of lithium. At the same time, production costs are further reduced by recycling by-products and waste.

[0098] In the entire production process, the present invention adopts a number of environmental protection measures to effectively reduce the discharge of wastewater and waste. In particular, in the step-by-step concentration stage, the use of reverse osmosis membranes and electrodialysis equipment achieves zero wastewater discharge, greatly reducing the negative impact on the environment. In addition, by recycling and reusing washing water and deionized water, etc., the consumption of water resources is further reduced.

[0099] The present invention significantly improves the recovery rate of lithium through multi-step purification and recovery, especially in the lithium precipitation reaction and decarbonization adjustment stage, improves the purity of lithium, and also realizes the re-extraction of lithium in non-lithium carbonate wet materials, thereby further improving the recovery rate of lithium. This measure not only reduces resource waste, but also enhances environmental sustainability.

[0100] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0101] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A waste battery lithium recovery device based on membrane separation technology, characterized in that: include: A reverse osmosis shell assembly, the reverse osmosis shell assembly comprising a shell (101), a joint (102), a liquid inlet pipe (103), a concentrated water pipe (105), and a liquid outlet pipe (106); A reverse osmosis assembly is arranged in a reverse osmosis shell assembly, and the reverse osmosis assembly is used to preliminarily concentrate slurry. The reverse osmosis assembly comprises a liquid storage pipe (201), a pure water pipe (202) and a clean pipe (203) which are arranged in sequence from left to right inside the shell (101). The pure water pipe (202) is fixedly connected to one end of the liquid storage pipe (201), and the pure water pipe (202) is fixedly penetrated through the clean pipe (203) and is connected to the concentrated water pipe (105). Four reverse osmosis membranes (204) are fixedly embedded in the surface of the pure water pipe (202). Four permeable pipes (205) are fixedly embedded in the middle of the side walls at relative positions of the liquid storage pipe (201) and the clean pipe (203), and the inside of the permeable pipe (205) The reverse osmosis membrane (204) is spirally wound on the surface of the pure water pipe (202) and the water permeable pipe (205), respectively; the inner wall of the water permeable pipe (205) is fixedly connected to a guide frame (206); the surface of the guide frame (206) is movably connected to a filter belt (207) for pre-filtering the anode slurry; a plurality of connecting pipes (210) are fixedly embedded in the middle of the cleaning pipe (203), and the connecting pipes (210) are connected to the inside of the liquid outlet pipe (106); the joint (102) is threadedly connected to one end of the opening of the housing (101); the middle of the joint (102) is fixedly connected to the liquid inlet pipe (103); The liquid storage tube (201) and the cleaning tube (203) are tightly fitted on the inner wall of the outer shell (101); a through hole is provided at one end of the liquid storage tube (201) corresponding to the position of the liquid inlet tube (103) so that the interior of the liquid inlet tube (103) is connected to the interior of the liquid storage tube (201); the concentrated water tube (105) and the liquid outlet tube (106) are respectively fixedly embedded in one end of the outer shell (101) away from the joint (102); the interior of the liquid outlet tube (106) is connected to the interior of the outer shell (101); a connecting tube (104) is fixedly provided on the inner wall of one end of the outer shell (101) away from the joint (102); the pure water tube (202) is movably plugged into the inner wall of the connecting tube (104), and the connecting tube (104) is connected to the inner wall of the connecting tube (104). The interior of the tube (104) is respectively connected to the interior of the pure water tube (202) and the concentrated water tube (105); a positioning tube (208) is fixedly connected to the surface of the pure water tube (202) corresponding to the position of the connecting tube (104); the positioning tube (208) is movably sleeved on the surface of the connecting tube (104); and a notch is provided at one end of the positioning tube (208) corresponding to the position of the concentrated water tube (105), so that the notch at one end of the positioning tube (208) cooperates with the concentrated water tube (105) to position the direction of the clean tube (203); a plurality of holes are provided in the middle of one end of the permeable tube (205) away from the clean tube (203); and the position of the holes in the middle of the permeable tube (205) corresponds to the position of the filter belt (207).so that the anode slurry inside the water permeable pipe (205) first passes through the filter belt (207) and enters the position between the reverse osmosis membrane (204) and the housing (101) from the hole in the middle of the water permeable pipe (205); the surface of the guide frame (206) corresponding to the position of the filter belt (207) is fixedly connected with a locking edge, and the locking edge is tightly fitted with both ends of the filter belt (207), so that the guide frame (206) cooperates with the locking edge to fit the filter belt (207) to the inner wall of the water permeable pipe (205); one end of the cleaning pipe (203) corresponding to the position of the liquid storage pipe (201) is fixedly connected with a liquid inlet grid (209), and the reverse osmosis membrane (204) is located between the liquid storage pipe (201) and the liquid inlet grid (209), so that the liquid that passes through the reverse osmosis membrane (204) enters the interior of the connecting pipe (210) through the liquid inlet grid (209) and is discharged from the liquid outlet pipe (106); A cleaning component is arranged in a reverse osmosis shell component and is used to clean impurities in a cleaning pipe (203). The cleaning component comprises a support frame (301) fixedly connected to the surface of a pure water pipe (202) via a bracket, and the support frame (301) is an annular structure. The support frame (301) is located inside the cleaning pipe (203). The filter belt (207) is movably wound around the surface of the support frame (301). The surface of the pure water pipe (202) corresponding to the position of the cleaning pipe (203) is fixedly connected to the fixing frame (302). One end of the fixing frame (302) corresponding to the position of the filter belt (207) is rotatably connected to a driving roller (303) for driving the filter belt (207) via a bearing. The filter belt (207) is tightly fitted between the driving roller (303) and the fixing frame (302). The fixing frame (302) is located away from the driving roller (303). A brush is provided at the end, and the brush is tightly attached to the inner wall of the filter belt (207), so that when the filter belt (207) is driven, impurities on the inner wall of the filter belt (207) are cleaned by the brush. One end of the output shaft of the driving roller (303) is fixedly connected to a bevel gear (304), a bevel gear ring (305) is meshed on the surface of the bevel gear (304), a driving gear (307) is meshed on the surface of the bevel gear ring (305), and the driving gear (307) is eccentrically arranged with the bevel gear ring (305). A sewage pipe (309) is fixedly embedded in the bottom of one end of the housing (101) away from the joint (102), and a control valve is provided in the middle of the sewage pipe (309). A sewage outlet is provided at one end of the cleaning pipe (203) corresponding to the sewage pipe (309), so that impurities in the cleaning pipe (203) are discharged to the outside through the sewage outlet and the sewage pipe (309).

2. According to claim 1, a waste battery recycling and lithium extraction device based on membrane separation technology is characterized in that: A groove is provided on the surface of the housing (101) at a position corresponding to the driving gear (307) so that the driving gear (307) meshes with the helical gear ring (305); a second guide ring (308) is fixedly connected to the surface of the housing (101) at a position corresponding to the driving gear (307), and the second guide ring (308) is rotatably connected to the inner wall of the driving gear (307) so that the second guide ring (308) has a limiting effect on the driving gear (307); sealing grooves are provided at both ends of the helical gear ring (305), and the inner wall of the sealing groove is rotatably connected to the first guide ring (306); the first guide ring (306) is fixedly connected to the inner wall of the cleaning tube (203) so that the first guide ring (306) cooperates with the sealing groove to limit the helical gear ring (305) and prevents liquid from leaking from the connection between the helical gear ring (305) and the driving gear (307).

3. A process for recycling and extracting lithium from waste batteries using the membrane separation technology according to any one of claims 1 to 2, characterized in that: The following steps are involved: S1. Prepare cathode slurry: take one or more metal compound solutions and a conductive polymer, add deionized water to prepare a cathode slurry, wherein the metal compound solution and the conductive polymer include one or a mixture of nickel sulfate solution, cobalt sulfate solution, lithium sulfate solution, manganese sulfate solution, nickel chloride solution and polyaniline solution; S2. Prepare anode slurry: take waste battery powder and add deionized water to prepare anode slurry; S3, electrolysis reaction: circulating the cathode slurry prepared in step S1 into the cathode chamber of the electrolytic cell, continuously passing the anode powder slurry prepared in step S2 into the anode chamber of the electrolytic cell, connecting to a power source, wherein the cathode chamber and the anode chamber of the electrolytic cell are separated by an anion membrane so that lithium ions do not pass through the diaphragm, and at the same time, replenishing the cathode slurry into the cathode chamber and recovering the electrolysis product to ensure the stability of the current; S4, filter pressing: passing the anode slurry after electrolysis in step S3 into a filter press to separate the lithium-containing solution and the solid residue, passing the lithium-containing solution into a microporous filter for purification to remove insoluble impurities; S5, step-by-step concentration: the lithium-containing solution refined in step S4 is passed into a reverse osmosis shell assembly for preliminary concentration, and then the lithium-containing solution concentrated by the reverse osmosis membrane is passed into an electrodialysis device to further increase the concentration of lithium in the lithium-containing solution. At the same time, the deionized water produced by the reverse osmosis is used to prepare the anode slurry in step S2 and is reserved for standby use. The fresh water produced by the electrodialysis is returned to the reverse osmosis shell assembly for reuse. No wastewater is discharged during the entire concentration process; S6, lithium precipitation reaction: adding sodium carbonate solution to the lithium-containing solution concentrated in step S5, and preparing lithium carbonate slurry by reaction, wherein the molar ratio of lithium element to sodium carbonate is 1:0.5-0.8, and the reaction time is 30-120 minutes; S7, obtaining a battery-grade lithium carbonate product: passing the lithium carbonate slurry in step S6 into a centrifuge for high-speed separation and dehydration to obtain a lithium carbonate wet material, and washing the dehydrated lithium carbonate wet material with washing water, while recovering the washed solution, and then dehydrating and drying, air flow crushing, demagnetizing and packaging the lithium carbonate wet material after centrifugal washing in turn to obtain a battery-grade lithium carbonate product.

4. The process of the waste battery recycling and lithium extraction device based on membrane separation technology according to claim 3 is characterized in that: The waste battery powder in step S2 includes one or a mixture of lithium iron phosphate battery powder, ternary battery powder, lithium cobalt oxide battery powder, lithium manganese oxide battery powder, lithium iron manganese phosphate battery powder and solid-state battery powder, and the solid-liquid ratio of the anode slurry in step S2 ranges from 10% to 20%. The electrolysis products recovered in step S3 include hydrogen, metallic copper and metallic nickel. In step S7, the dehydrated lithium carbonate wet material is washed 1 to 3 times with washing water, and the washed solution recovered in step S7 is used for the preparation of the sodium carbonate solution in step S6. The washing water in step S7 includes one or a mixture of the deionized water and pure water reserved for standby in step S5.

5. The process of the waste battery recycling and lithium extraction device based on membrane separation technology according to claim 4 is characterized in that: The specific steps of recovering the washed solution in step S7 include: S11, decarbonization and value adjustment: adding an acidic regulator to the solution of the non-lithium carbonate wet material separated after centrifugation in step S7, adjusting the pH to 2-4, and then adding an alkaline regulator to adjust the pH to 7-9 to obtain a value adjustment solution, so that the solution of the non-lithium carbonate wet material separated after centrifugation in S7 is subjected to lithium extraction again, thereby improving the recovery rate of lithium and recovering by-products at the same time; S12, MVR evaporation and desalination: the adjusted solution in step S11 is passed into MVR for evaporation and concentration to obtain by-product industrial salt, and the concentrated solution is processed again by steps S6 and S7, wherein the deionized water produced by MVR is reused in step S2 for preparing anode slurry.

6. The process of the waste battery recycling and lithium extraction device based on membrane separation technology according to claim 5 is characterized in that: The acidic regulator in step S11 includes one or a mixture of hydrochloric acid, sulfuric acid, nitric acid and phosphoric acid, the alkaline regulator in step S11 includes one or a mixture of sodium hydroxide and lithium hydroxide, and the industrial salt in step S12 includes one or a mixture of sodium chloride, sodium sulfate, sodium nitrate and sodium phosphate.

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