Method for recovering a battery
Through continuous drying methods and devices, the problems of heavy equipment load, large temperature fluctuations and high energy consumption in battery recycling have been solved, the stability and energy efficiency of the equipment have been improved, the humidity of the mixture has been reduced, the risk of equipment explosion has been reduced, and the service life of the equipment has been extended.
Patent Information
- Application Number
- CN202410697216.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2024-03-26
- Filing Date
- 2024-05-31
- Publication Date
- 2025-09-26
AI Technical Summary
In existing battery recycling methods, batch drying operations result in heavy loads on equipment components, large temperature and pressure fluctuations, short equipment life and high energy consumption, difficulty sealing the drum dryer, and high HF loads at high temperatures.
A continuous drying method is adopted, which includes crushing the battery to form a solid material and electrolyte mixture, conveying it to the drying unit through a feed gate, drying it together with the existing mixture, continuously discharging the electrolyte, using negative pressure and heating units to promote evaporation, drying the mixture at a lower temperature, utilizing pneumatic and mechanical conveying units for material transportation, and recovering the electrolyte through a liquid ring pump to generate negative pressure and an electrolyte condenser.
Reduce the load on equipment components, extend equipment life, reduce energy consumption, achieve mixture humidity ≤ 10%, improve equipment stability, reduce temperature and pressure fluctuations, reduce explosion risks, and improve equipment service life and energy efficiency.
Smart Images
Figure CN120709565A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a method for recycling batteries. Background Art
[0002] In conventional battery recycling methods, the batteries to be recycled are dried in batches. To this end, the entire recycling facility must be designed to support batch drying operations, for example by providing large buffer stores. Furthermore, batch operation places significant strain on all sealing and heating components, as they are constantly exposed to highly varying conditions, often changing suddenly from the state at the end of a batch to the state at the beginning of the next.
[0003] There are also continuously operating systems on the market, primarily based on drum dryers. Here, the electrolyte is burned or pyrolyzed at high temperatures with the exclusion of air. The disadvantage of these systems is the high temperatures, which result in a high HF load in the exhaust gas. Another drawback of drum dryers is that they are difficult to make leak-tight, as this requires a large sealing surface, making stable pyrolysis more difficult. Summary of the Invention
[0004] It is therefore an object of the present invention to provide a method for recycling batteries or a device of this type which is improved compared to the prior art.
[0005] The object of the present invention is achieved by a method for recycling batteries, which comprises the following steps:
[0006] - crushing the battery to produce a mixture comprising a solid matter formed from the crushed battery and an electrolyte;
[0007] - conveying the mixture to the feed gate;
[0008] - the mixture is transferred through the feed gate into a drying unit designed to dry the mixture;
[0009] - drying the mixture introduced into the drying unit continuously together with the mixture already in the drying unit, which mixture had been introduced into the drying unit at an earlier point in time;
[0010] - continuously draining the electrolyte evaporated from the mixture from the drying unit;
[0011] - The dried mixture is discharged from the drying unit via a discharge gate.
[0012] In contrast to batch operation, "continuous" generally refers to essentially uninterrupted or continuous operation. However, some fluctuations may occur in continuous operation. However, these fluctuations are much smaller than in batch operation, particularly with regard to temperature fluctuations in the drying unit. This continuous operation largely avoids the significant temperature and / or pressure fluctuations that can occur in equipment suitable for this method, particularly in the apparatus according to the present invention. This reduces the load on equipment components, extends the component life, and therefore increases the service life of the equipment.
[0013] Furthermore, the method according to the invention, in particular by means of a continuous drying step, can offer the advantage that a plant suitable for the method, in particular the apparatus according to the invention, can be operated more energy-efficiently than a batch-operated plant.
[0014] One factor in achieving this energy-saving operation is that the successive drying steps of the process according to the invention can be carried out at significantly lower temperatures compared to known drum dryers.
[0015] When removing the electrolyte from the mixture, approximately 70% to 90% of the electrolyte contained in the mixture at the inlet, ie in the crushing zone, can be removed from the mixture and discharged, in particular recovered.
[0016] In other words, the final moisture content achievable by the method according to the invention, ie the moisture content in the mixture achieved using the method according to the invention, can be up to ≤10%, in particular up to ≤5%, advantageously up to ≤3%.
[0017] Within the scope of the present invention, drying can be carried out, for example, at a pressure of 50 to 750 mbar, in particular about 100 mbar, and / or at a temperature of 80 to 120° C., in particular about 100° C.
[0018] Advantageously, the method may further comprise, before the crushing step, the step of disassembling the battery into battery subunits, each battery subunit having a smaller size than the battery. This step may include manually and / or automatically disassembling the battery into battery subunits. For example, during the step of disassembling the battery into battery subunits, the outer packaging of the original battery cells may be removed, thereby allowing the so-called battery pack to be disassembled into individual cells.
[0019] In particular, the mixture can be conveyed using a conveying unit that is designed to pneumatically and / or mechanically convey the mixture to the feed gate. Thus, the conveying unit can be operated, for example, pneumatically, by blowing and / or sucking gas along the conveying path of the conveying unit to convey the mixture to the feed gate. The gas can include air and / or nitrogen. The conveying unit can be operated mechanically, for example, using a conveyor belt or a screw conveyor.
[0020] The method may further comprise the step of continuously condensing the electrolyte discharged from the drying unit. In this way, electrolyte from the drying unit that evaporates from the mixture can be condensed and recovered.
[0021] The method may further include the step of generating a negative pressure in the drying unit. The negative pressure in the drying unit may facilitate evaporation of the electrolyte from the mixture or increase an evaporation rate of the electrolyte from the mixture.
[0022] In this case, a liquid ring pump can be used to generate the negative pressure in the drying unit, which is particularly designed to generate a liquid ring using electrolyte. The formation of the liquid ring in the liquid ring pump can particularly be carried out using electrolyte that is discharged from the drying unit and then condensed.
[0023] The pressure upstream of the feed lock, viewed in the material flow direction of the mixture, can be different from, and in particular, higher than, the pressure downstream of the feed lock. For example, the pressure upstream of the feed lock can be substantially ambient pressure, while the pressure downstream of the feed lock can be substantially the pressure also prevailing within the drying unit. As will be described below with reference to the apparatus according to the present invention, the feed lock can be designed to selectively achieve pressure equalization between the pressures generated upstream of the feed lock and the pressures generated downstream of the feed lock.
[0024] The method may further comprise the step of heating the mixture in the drying unit. Such heating of the mixture may also facilitate evaporation of the electrolyte from the mixture or increase the evaporation rate of the electrolyte from the mixture.
[0025] To ensure better and more thorough mixing of the mixture newly introduced into the drying unit with the mixture already in the drying unit, the method may further include the step of turning the mixture during the drying step. To this end, the drying unit may include a shaft rotatably mounted on the drying unit housing. The shaft may be provided with only mixing blades. When the shaft is driven by a motor, the mixing blades rotate with the shaft and are arranged to thoroughly mix the mixture within the drying unit.
[0026] The method can also include the step of pre-drying upstream of and / or within the feed gate. Thus, pre-evaporation of the electrolyte from the mixture can already take place in the area of the feed gate. The electrolyte discharged during this pre-evaporation can then be fed to the electrolyte discharged directly from the drying unit or processed in a similar manner. In the method according to the invention, the pre-evaporation in the area of the feed gate allows for a two-stage drying of the mixture.
[0027] On the other hand, the aforementioned object of the present invention is achieved by a device for recycling batteries, the device comprising:
[0028] a crushing unit designed to crush the batteries to produce a mixture comprising a solid matter formed from the crushed batteries and an electrolyte;
[0029] - a conveying unit designed to convey the mixture to the feed gate;
[0030] - a drying unit designed to dry the mixture transferred into the drying unit through the feed gate;
[0031] wherein the drying unit is designed to continuously dry the mixture introduced into the drying unit together with a mixture already in the drying unit, which mixture having been introduced into the drying unit at an earlier point in time;
[0032] - an electrolyte discharge unit designed to continuously discharge electrolyte evaporated from the mixture from the drying unit;
[0033] - A discharge gate designed to discharge the dried mixture from the drying unit.
[0034] It should be noted that all features, functions and advantages mentioned with respect to the method according to the invention can also be applied to the device according to the invention, and vice versa. In particular, the device according to the invention can be designed to implement the method according to the invention.
[0035] The fragmentation unit can operate in a gaseous environment, in particular nitrogen and / or air, or in a liquid environment, in particular water. For example, when the fragmentation unit operates in a textile environment and / or a liquid environment, the risk of explosion can be reduced, even if it cannot be avoided, thereby reducing the danger to the user of the device and / or damage to the device.
[0036] The device may include at least one intermediate storage for temporarily storing the mixture. For example, an intermediate storage may be arranged upstream of the delivery unit to achieve a uniform supply to the delivery unit and thus to deliver the mixture. Such an intermediate storage may, for example, have a maximum throughput of 2 to / h and / or 1 m 3The maximum capacity.
[0037] The electrolyte drain unit may include at least one filter which is designed to prevent foreign matter, in particular solid matter, from escaping from the drying unit.
[0038] In one embodiment of the device according to the invention, the inlet and / or outlet locks can be adapted to selectively receive the pressure upstream of the inlet and / or outlet locks or downstream of the inlet and / or outlet locks in a lock volume, wherein the inlet and / or outlet locks can in particular comprise at least one of a rotary lock, a double flap lock, a swing slide, a pivoting flap, a ball valve, and a squeeze valve. Thus, the lock volume can, for example, be adjusted to the pressure upstream of the conveying unit, such as ambient pressure, or to the pressure in the drying unit, such as a negative pressure of 100 mbar.
[0039] The inlet and / or outlet gates may also include a sealing unit designed to seal a movable element of the inlet and / or outlet gates (e.g., relative to a surrounding housing). The sealing unit may have a conical profile in order to adapt to the movement of the movable element and thus improve the sealing effect. The sealing unit may be a pneumatic sealing unit, which achieves or strengthens the sealing effect of the sealing element by the gas present in the sealing unit.
[0040] The apparatus may also include a heating unit designed to heat the housing surrounding the drying unit and / or the feed gate. By heating the housing walls, thermal energy can be released into the interior of the housing and, in turn, into the mixture. This heating of the mixture can promote electrolyte evaporation, particularly outside the negative pressure within the drying unit, thereby increasing the rate of electrolyte evaporation from the mixture.
[0041] Advantageously, the device can also include an electrolyte condenser designed to continuously condense the electrolyte discharged from the drying unit. This continuous discharge and condensation of the electrolyte allows the electrolyte to be recovered from the mixture, collected, and, if necessary, reprocessed for reuse. For this purpose, the electrolyte condenser can be equipped with an electrolyte collection container.
[0042] In order to continuously drain the electrolyte from the drying unit and direct it to the electrolyte condenser, the electrolyte condenser can be fluidically connected to a liquid ring pump, which is designed to generate a negative pressure in the drying unit. The liquid ring pump can be designed to form a liquid ring with the electrolyte. For this purpose, in particular, electrolyte that has previously been recovered and condensed from the mixture by the electrolyte condenser can be used. For example, the liquid ring pump can be fluidically connected to an electrolyte collection container.
[0043] The apparatus may also include or be connected to a sorting device designed to sort the mixture discharged from the drying unit. This sorting can be performed, for example, based on the material, size, and / or weight of the mixture's components. Therefore, a receiving container can be arranged downstream of the discharge gate, designed to receive the mixture discharged from the drying unit and transfer it to the sorting device. A separate vacuum pump can be assigned to the receiving container to pneumatically convey the mixture to the receiving container and thus toward the sorting device. BRIEF DESCRIPTION OF THE DRAWINGS
[0044] The present invention will be described in more detail below by way of examples with reference to the accompanying drawings, in which:
[0045] Figure 1 is a schematic diagram of an apparatus for recycling batteries according to the present invention. DETAILED DESCRIPTION
[0046] exist Figure 1 In the schematic diagram of FIG, an apparatus for recycling batteries according to the present invention is generally indicated by reference numeral 10. The apparatus 10 comprises a hopper 12 into which batteries to be recycled or their sub-components after undergoing the disassembly steps can be filled.
[0047] exist Figure 1 In the illustrated embodiment, a crushing unit 14 is disposed within the hopper 12. The crushing unit is designed to crush the batteries to produce a mixture comprising solid matter formed from the crushed batteries and electrolyte. The crushing unit 14 can operate in a gaseous or liquid environment. For example, the crushing unit 14 can be a mechanical pulverizer. Thus, the pulverizer's cutting tools can be surrounded by a gas, particularly air or nitrogen for inerting, or by a liquid, particularly water, during operation.
[0048] About the mixture along Figure 1 A first intermediate storage 16 is arranged downstream of the crushing unit 14, viewed in the conveying direction of the illustrated apparatus 10. This first intermediate storage 16 is designed, in particular, to temporarily store the mixture before it is conveyed further via a first conveying unit 18 arranged downstream of the first intermediate storage 16. The first conveying unit 18 can be a mechanical conveying unit, such as a conveyor belt, and / or a pneumatic conveying unit, in particular a suction conveying unit, which uses, for example, nitrogen to transfer the mixture from the first intermediate storage 16 to a feed lock 20.
[0049] The feed gate 20 comprises a swing slide 22 which is designed to Figure 1The bottom side of the feed lock 20 is shown, and thus the lock volume of the feed lock 20 is opened or closed relative to the drying unit 24. Since negative pressure exists within the interior of the drying unit 24 in the illustrated embodiment, the feed lock 20 is designed to equalize the pressure within the drying unit 24 before the swing slide 22 is opened. To this end, the interior of the drying unit 24 is connected to the lock volume of the feed lock 20 via a pressure equalization line 26. A first shutoff valve 28 is disposed in the pressure equalization line 26, which is designed to prevent or allow fluid flow through the pressure equalization line. A second shutoff valve 30 is arranged in the first conveying unit 18, which is also designed to fluidically separate or connect the lock volume of the feed lock 20 from the upstream side of the second shutoff valve 30. If the first shutoff valve 28 is closed and the second shutoff valve 30 is opened, the pressure in the feed lock 20 becomes substantially the same as the pressure in the first conveying unit 18, for example, ambient pressure, and the mixture can be supplied to the feed lock 20. If the mixture in the feed lock 20 is now to be loaded into the drying unit 24, the second shut-off valve 30 is closed and the first shut-off valve 28 is opened, so that the pressure in the lock volume of the feed lock is equalized with the pressure in the drying unit 24. The swing slide 22 can then be opened and the mixture can be transferred into the drying unit 24.
[0050] As mentioned above, the interior of the drying unit 24 is under a negative pressure of, for example, 100 mbar. Additionally, the interior of the drying unit 24 is heated, for example, to approximately 100°C, by a heating unit, which, in the embodiment shown here, is arranged in the housing 32 of the drying unit 24. The mixture newly introduced into the drying unit 24 is mixed there with the mixture already present in the drying unit 24, so that heat energy is transferred from the already heated mixture to the newly introduced mixture. To support this effect, mixing blades 34 are arranged in the interior of the drying unit 24. These mixing blades are connected to a common shaft 36, wherein shaft 36 is rotated by a motor 38, causing the mixing blades 34 to rotate relative to the housing 32 of the drying unit 24.
[0051] Depending on the environmental parameters, negative pressure and heating in the drying unit 24, the electrolyte evaporates from the mixture. The evaporated electrolyte is now continuously discharged from the interior of the drying unit 24 via the electrolyte discharge unit 40, wherein the electrolyte can in particular pass through at least one filter to filter out solids. An electrolyte condenser 42 is connected to the electrolyte discharge unit 40, which is designed to continuously condense the electrolyte discharged from the drying unit 24. The condensed electrolyte is then collected in an electrolyte collection container 44. In the embodiment shown here, in order to be able to discharge the evaporated electrolyte from the drying unit 24 via the electrolyte discharge unit 40 to the electrolyte condenser 42, the electrolyte condenser 42 is connected to a vacuum pump 46, in the embodiment shown to a liquid ring pump 46.
[0052] exist Figure 1 At the lower right end of the drying unit 24, the interior of the drying unit 24 is connected to a discharge gate 48, which is designed to discharge the dried mixture from the drying unit 24. The discharge gate 48 comprises a first oscillating slide 50 and a second oscillating slide 52. Similar to the operation of the feed gate 20, the discharge gate 48 is also designed to selectively achieve pressure equalization with the interior of the drying unit 24 or with the downstream side of the discharge gate 48. If the gate volume of the discharge gate 48 has already achieved pressure equalization with the interior of the drying unit 24, the first oscillating slide 50 can be opened, and the dried mixture can be introduced into the gate volume of the discharge gate 48. Subsequently, the first oscillating slide 50 is closed, and the gate volume of the discharge gate 48 is brought to the pressure downstream of the second oscillating slide 52, which in the illustrated embodiment corresponds to ambient pressure. When this pressure balance is achieved, the second pivot slide 52 opens and the mixture is introduced from the lock volume of the outlet lock 48 into a second intermediate storage 54 , which operates essentially like the first intermediate storage 16 .
[0053] The second intermediate storage 54 is in turn assigned a second conveying unit 56 , by means of which the mixture located in the second intermediate storage 54 can be transported away mechanically and / or pneumatically.
[0054] exist Figure 1 In the illustrated embodiment, a receiving container 58 is additionally shown. This receiving container is connected to the downstream end of the second conveying unit 56 and is designed to temporarily receive the dried mixture. A sorting device (not shown) can be arranged downstream of the receiving container 58. This sorting device is designed to sort the dried mixture. This sorting can be performed, for example, based on the material and / or size and / or weight of the components of the mixture.
[0055] In order to enable pneumatic transport along the second conveying unit 56 , the receiving container 58 or the second conveying device 56 is connected here to a vacuum pump 60 .
Claims
1. A method for recycling batteries, comprising the following steps: - crushing the battery to produce a mixture comprising a solid substance formed from the crushed battery and an electrolyte; - conveying the mixture to the feed gate (20); - transferring the mixture through the feed lock (20) into a drying unit (24), which is designed to dry the mixture; - continuously drying the mixture introduced into the drying unit (24) together with the mixture already in the drying unit (24) which was introduced into the drying unit (24) at an earlier point in time; - continuously discharging electrolyte evaporated from the mixture from the drying unit (24); - Discharge of the dried mixture from the drying unit (24) via a discharge gate (48).
2. The method according to claim 1, characterized in that The method further comprises the following steps before the crushing step: - disassembling the battery into battery subunits, each of the battery subunits having a smaller size than the battery.
3. The method according to any one of the preceding claims, characterized in that The mixture is conveyed using a conveying unit (18) which is designed to convey the mixture to the feed lock (20) pneumatically and / or mechanically.
4. The method according to any one of the preceding claims, characterized in that The method further comprises the following steps: - Continuously condensing the electrolyte discharged from the drying unit (24).
5. The method according to any one of the preceding claims, characterized in that The method further comprises the following steps: - generating a negative pressure in the drying unit (24).
6. Method according to the preceding claim, characterized in that The negative pressure is generated in the drying unit (24) using a liquid ring pump (46) which is designed in particular for forming a liquid ring with an electrolyte.
7. The method according to any one of the preceding claims, characterized in that Viewed in relation to the material flow direction of the mixture, the pressure upstream of the feed lock (20) is different from, in particular higher than, the pressure downstream of the feed lock (20).
8. The method according to any one of the preceding claims, characterized in that The method further comprises the following steps: - Heating the mixture in the drying unit (24).
9. The method according to any one of the preceding claims, characterized in that The method further comprises the following steps: - Turn the mixture over during the drying step.
10. The method according to any one of the preceding claims, characterized in that The method further comprises the following steps: - Pre-drying is carried out upstream of and / or inside the feed lock (20).
11. A device (10) for recycling batteries, comprising: a crushing unit (14) designed to crush the batteries to produce a mixture comprising a solid mass formed from the crushed batteries and an electrolyte; a conveying unit (18) designed to convey the mixture to a feed gate (20); a drying unit (24) designed to dry the mixture transferred into the drying unit (24) through the feed lock (20); wherein the drying unit (24) is designed to continuously dry the mixture introduced into the drying unit (24) together with the mixture already in the drying unit (24), The mixture already in the drying unit (24) has been introduced into the drying unit (24) at an earlier point in time; - an electrolyte discharge unit designed to continuously discharge electrolyte evaporated from the mixture from the drying unit (24); A discharge lock (48) is designed to discharge the dried mixture from the drying unit (24).
12. The device (10) according to claim 11, characterized in that The feed gate (20) and / or the discharge gate (48) are adapted to selectively receive the pressure upstream of the feed gate (20) or the discharge gate (48) or the pressure downstream of the feed gate (20) or the discharge gate (48) in a gate volume, wherein the feed gate (20) and / or the discharge gate (48) particularly comprises at least one of a rotating gate, a double-flapping gate, a swinging slide (22, 50, 52), a pivoting valve flap, a ball segment valve (28, 30) and a squeeze valve.
13. The device (10) according to claim 11 or 12, characterized in that The device further comprises a heating unit designed to heat a housing (32) surrounding the drying unit (24) and / or the feed gate (20).
14. The device (10) according to any one of claims 11 to 13, characterized in that The apparatus (10) further comprises an electrolyte condenser (42) designed to continuously condense the electrolyte discharged from the drying unit (24).
15. The device (10) according to claim 14, characterized in that The electrolyte condenser (42) is fluidically connected to a liquid ring pump (46) which is designed to generate a negative pressure in the drying unit (24).