Rotary kiln with crushing function for recycling waste lithium batteries

Abstract

The application provides a rotary kiln with a crushing function for recycling waste lithium batteries, which comprises, along a material flow direction, a feeding hopper, a rotary kiln body and a discharge bin which are sequentially connected, the rotary kiln body is connected with a driving mechanism, and the driving mechanism is used for driving the rotary kiln body to rotate; at least one flap valve is arranged at an inlet end of the feeding hopper, a crushing device is arranged in the feeding hopper, and a flue gas outlet is further formed at the top of the feeding hopper; a discharge port is formed at the bottom of the discharge bin, and a protective gas inlet is formed at the top of the discharge bin, and nitrogen or low-oxygen waste gas is introduced into the rotary kiln body through the protective gas inlet. The rotary kiln provided by the application can realize crushing and high-temperature heat treatment of waste lithium batteries, so that the waste lithium batteries can be safely disposed and the electrolyte can be effectively removed, dry battery fragments are obtained, and further separation and sorting at the back end are facilitated.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of waste lithium battery recycling, and relates to a rotary kiln with a crushing function for waste lithium battery recycling. BACKGROUND

[0002] With the continuous growth of human social energy demand, batteries as a portable energy storage device, the proportion in the society and people's daily life is getting larger and larger, becoming one of the third largest consumer goods. Among them, lithium ion batteries are widely used in electronic, transportation, energy storage and aerospace fields due to their low cost, good safety performance, long service life, high specific energy, no memory effect, environmental friendliness and other obvious advantages. Lithium ion battery is an important electronic basic product and an important support for the development of new energy and new energy electric vehicles, and is widely used in consumer electronics, power and energy storage systems.

[0003] It is estimated that in the next few years, a large number of waste batteries will be generated after the service life of lithium ion batteries ends. The abandoned lithium battery contains a large amount of non-renewable and high-value metal resources. The positive material in the lithium battery is lithium cobaltate powder, and the negative material is graphite powder. Both the positive plate and the negative plate contain a large amount of nickel, copper, aluminum and other metal materials. From the perspective of its huge quantity, environmental protection and resource regeneration, waste lithium ion batteries have high recycling value and potential. If waste or unqualified lithium batteries can be effectively recycled, not only can the pressure of waste batteries on the environment be reduced, but also the waste of cobalt, nickel and other metal resources can be avoided.

[0004] Lithium ion batteries are a complex chemical system, and it is difficult to commercialize the direct recovery of positive materials, negative materials, electrolyte and separator from waste lithium batteries. The method of burning to remove the electrolyte and the binder polyvinylidene fluoride will cause the aluminum foil in the waste lithium battery to melt and cover the active material, and even generate lithium aluminate, making it difficult to separate the active material and the aluminum foil and extract valuable metal elements. The physical method for treating waste lithium batteries for recycling, that is, using the physical properties such as magnetism and density of the material to separate the waste lithium battery materials, does not need to use chemical reagents, and the energy consumption is lower, but the positive and negative active materials of the old lithium ion battery are often adhered to the separator, and it is difficult to achieve good separation effect. When valuable metals are extracted, the inorganic acid and reducing agent leaching method will consume a large amount of inorganic acid and reducing agent, and a large amount of alkali solution is needed for neutralization of the solution in the later stage, causing unnecessary waste. SUMMARY

[0005] In view of the deficiencies of the prior art, the present application aims to provide a rotary kiln with crushing function for recycling waste lithium batteries, which can realize crushing and high-temperature heat treatment of waste lithium batteries, so that the waste lithium batteries can be safely disposed and the electrolyte can be effectively removed, obtaining dry battery fragments, which is beneficial to further separation and sorting at the back end. The traditional disposal process of waste lithium batteries generally needs to be pretreated by discharging + nitrogen protection crushing. The device can directly realize the crushing of waste lithium batteries under the condition of nitrogen / low-oxygen waste gas environment, and perform heating treatment to evaporate the electrolyte, solving the risk and hidden danger of battery crushing under electricity, and realizing the process of directly crushing and heat treating the battery to evaporate the electrolyte from the complete battery.

[0006] To achieve this purpose, the present application adopts the following technical solutions:

[0007] The present application provides a rotary kiln with crushing function for recycling waste lithium batteries, which comprises a feeding hopper, a rotary kiln body and a discharge bin connected in sequence along the material flow direction, the rotary kiln body is connected with a driving mechanism, and the driving mechanism is used to drive the rotary kiln body to rotate.

[0008] At least one flap valve is arranged at the inlet end of the feeding hopper, a crushing device is arranged inside the feeding hopper, and a flue gas outlet is formed at the top of the feeding hopper.

[0009] A discharge port is formed at the bottom of the discharge bin, and a protective gas inlet is formed at the top of the discharge bin, through which nitrogen or low-oxygen waste gas is introduced into the rotary kiln body.

[0010] The rotary kiln provided by the present application is mainly used for recycling crushed waste lithium batteries, and the device mainly comprises a feeding hopper, a rotary kiln body and a discharge bin. The battery does not need to be discharged, but is directly sent into the feeding hopper through the feeding end, falls into the crushing device through multiple flap valves, and the crushing device is in a nitrogen / low-oxygen waste gas protective atmosphere, ensuring the safety of the waste lithium battery crushing under the condition of being charged. The battery fragments after crushing enter the rotary kiln body through the chute, and the electrolyte of the waste lithium battery volatilizes after being heated in the rotary kiln body, and is discharged together with the protective gas in the rotary kiln body through the flue gas outlet. The heating time of the rotary kiln body is about 1-2h, and the heating temperature is about 100-600-℃. The waste lithium battery after heating enters the discharge bin for cooling, for further crushing and sorting at the back end.

[0011] The rotary kiln provided by the application can realize crushing and high-temperature heat treatment of waste lithium batteries, so that the waste lithium batteries can be safely disposed and the electrolyte can be effectively removed, dry battery fragments are obtained, and further separation and sorting at the back end is facilitated. The traditional disposal process of waste lithium batteries generally needs to be pretreated by discharging + nitrogen protection crushing, the device can directly realize the crushing of the waste lithium batteries under the condition of nitrogen / low-oxygen exhaust gas environment, and heating treatment is performed to evaporate the electrolyte, the risk and hidden danger of battery crushing under electricity are solved, and the process of directly crushing and heat treating the battery to evaporate the electrolyte from the complete battery is realized.

[0012] As a preferred technical solution of the application, the crushing device comprises a first crushing roller and a second crushing roller arranged side by side in the horizontal direction, and the first crushing roller and the second crushing roller are meshed through the teeth to crush the waste lithium batteries.

[0013] One end of the first crushing roller extends to the outside of the feed hopper and is fixedly connected with a first gear, one end of the second crushing roller extends to the outside of the feed hopper and is fixedly connected with a second gear, the first gear and the second gear are driven through the meshing of the teeth, and one end of the first crushing roller extending out of the feed hopper is also connected with a driving device for rotating the first crushing roller.

[0014] As a preferred technical solution of the application, the rotary kiln body is arranged obliquely, and a plurality of partitions are arranged in the axial direction inside the cavity of the rotary kiln body, and the partitions divide the inner cavity of the rotary kiln body into a plurality of crushing cavities in communication with each other.

[0015] A central discharge port is formed in the center of the partition, and a plurality of edge material leakage notches are arranged in the circumferential direction at the edge of the partition, the edge material leakage notches are distributed around the central discharge port, and the opening of the edge material leakage notches is close to the inner wall of the cavity of the rotary kiln body.

[0016] In the application, a plurality of partitions are arranged to divide the rotary kiln body into a plurality of crushing cavities, thereby realizing multi-stage fine crushing of the waste lithium batteries.

[0017] As a preferred technical solution of the application, a stirring device is arranged in the inner cavity of the rotary kiln body, the rotating direction of the stirring device is opposite to the rotating direction of the rotary kiln body, and the stirring device comprises a stirring shaft and a plurality of stirring blades arranged on the stirring shaft.

[0018] At least one stirring blade is arranged in each crushing cavity, and the number of the stirring blades arranged in different crushing cavities is different; along the material flow direction, the number of the stirring blades in each crushing cavity gradually increases.

[0019] In the application, the rotation direction of the rotary kiln body is opposite to the rotation direction of the stirring device, the high-temperature gas in the rotary kiln body generates centrifugal force under the reverse rotation guide, thereby scattering against the inner wall of the rotary kiln body, effectively increasing the impact force of the high-temperature gas on the waste lithium battery, achieving the purpose of fully dispersing the waste lithium battery, and also ensuring that the waste lithium battery is fully heated, so that the electrolyte evaporates as soon as possible.

[0020] In the application, different stirring blades are arranged in different crushing cavities, the stirring blades in the crushing cavity near the one end of the feeding hopper are the least, the stirring blades in the crushing cavity near the one end of the discharging bin are the most, and the stirring blades in the middle crushing cavities gradually increase, so that the waste lithium battery is gradually crushed, and the waste lithium battery can be crushed to the required size in the corresponding crushing cavity.

[0021] It should be noted that the shape and number of the stirring blades are not specifically required, which can be flat, circular arc or spiral, etc., and the stirring blades with a circular arc structure are preferably adopted, the circular arc structure has better guiding property, and the impact force of the hot gas flow impacting the inner wall of the rotary kiln body can be increased.

[0022] As a preferred technical solution of the application, a press roller is arranged in each crushing cavity, the press roller has an axially through hole, the stirring shaft passes through the hole, the diameter of the stirring shaft is greater than the hole diameter of the hole, the press roller is eccentrically arranged between the stirring shaft, the axis of the press roller is lower than the axis of the stirring shaft and located directly below the axis of the stirring shaft, and the stirring shaft rotates at the same time to drive the press roller to slightly swing, so as to crush the material at the bottom of the crushing cavity.

[0023] The weights of the press rollers in different crushing cavities are different, and the weights of the press rollers in the crushing cavities gradually increase along the material flow direction.

[0024] Since the waste lithium battery contains substances with high viscosity such as a binder, when the waste lithium battery is crushed into fragments by the crushing device and enters the rotary kiln body, the battery fragments will be agglomerated to form fragment agglomerates under the action of the binder in the high-temperature environment in the rotary kiln body, and simple mechanical separation by the stirring device cannot realize the disassembly and dispersion of the fragment agglomerates; in addition, even if the fragment agglomerates can be dispersed, they will be agglomerated again due to the high-temperature environment and the binder.

[0025] In the rotation process of the rotary kiln body, the fragment agglomerates rotate with the kiln body, and when the fragment agglomerates rotate to a certain height, due to the slow rotation speed of the rotary kiln body and the small centrifugal force, the fragment agglomerates will fall to the bottom of the rotary kiln body under the action of gravity; then continue to rotate with the rotary kiln body, and again fall after rising to a certain height again, and the fragment agglomerates repeatedly perform the above process in the rotary kiln body, and if no treatment is taken, the fragment agglomerates are compacted by beating in the process of continuous lifting and falling, so that the fragment agglomerates are more compact and cannot be broken. Therefore, a press roller is arranged in each crushing cavity, and when the fragment agglomerates fall into the bottom of the rotary kiln body under the action of gravity, they are crushed and dispersed by the press roller; when the fragment agglomerates rotate to a certain height with the rotary kiln, due to the low temperature in the upper layer of the rotary kiln body, the temperature of the fragment agglomerates decreases, the activity of the binder decreases, and the fragment agglomerates slightly solidify, which is convenient for subsequent roller rolling; when the slightly solidified fragment agglomerates fall into the bottom of the rotary kiln body again, the press roller rolls the slightly solidified fragment agglomerates again, so that the fragment agglomerates can be further crushed and dispersed, and the cycle is repeated until the fragment agglomerates are completely dispersed.

[0026] As a preferred technical solution of the present application, the rotary kiln body comprises an inner kiln body and an outer kiln body located outside the periphery of the inner kiln body, and an inner layer of heat preservation material is laid between the outer kiln body and the inner kiln body, and an outer wall of the outer kiln body is laid with an outer layer of heat preservation material.

[0027] A heating channel is axially formed at the wall thickness of the inner kiln body, one end of the heating channel close to the feed hopper is the inlet end, and the opposite end is the outlet end; the inlet end is connected with a heating device, and the heat generated by the heating device enters the heating channel to heat the materials in the rotary kiln body.

[0028] The inner kiln body and the outer kiln body provided by the present application are combined and built by prefabricated bricks or special-shaped bricks, a heating channel penetrating through the entire inner kiln body is axially formed in the brick body of the inner kiln body, and the combustion flame or high-temperature gas flow accelerated by the air blowing system passes through the heating channel at high speed to heat the waste lithium batteries in the rotary kiln body.

[0029] The double-layer structure rotary kiln body provided by the present application can realize the isolation of the heating source and the waste lithium batteries, avoid the pollution of impurities in the heating flame or gas flow to the waste lithium batteries, and improve the heat transfer efficiency and heat preservation effect of the waste lithium batteries by arranging the inner layer of heat preservation material and the outer layer of heat preservation material.

[0030] It should be noted that the shape and number of the heating channels are not specifically required and specially limited in the present application, and can be a plurality of parallel heating channels arranged along the circumference of the rotary kiln body, the axis of each heating channel is parallel to the axial direction of the rotary kiln body, in order to cooperate with the pressure roller to disperse the agglomerates, the number of heating channels in the upper half of the inner layer kiln body is less than that in the lower half, so that the temperature of the upper layer inside the rotary kiln body is lower than that of the lower layer. Of course, the heating channels can also be helical along the axial direction of the rotary kiln body. However, it can be understood that any shape and any number of heating channels fall within the protection and disclosure range of the present application.

[0031] As a preferred technical solution of the present application, the discharge bin comprises a buffer chamber and a cooling chamber connected in sequence along the material flow direction, and a discharge port is formed in the bottom of the cooling chamber.

[0032] A gas pump, a rotary motor and a heat recovery tank are arranged in the buffer chamber, the gas inlet end of the gas pump is communicated with the outlet end of the heating channel, and the gas pump is used to extract the heat in the heating channel and then send it into the heat recovery tank.

[0033] The stirring shaft is a hollow structure, one end of the stirring shaft extends into the heat recovery tank, a heat recovery port is formed in the side wall of the end of the stirring shaft extending into the heat recovery tank, and the recovered heat in the heat recovery tank is injected into the hollow channel of the stirring shaft through the heat recovery port.

[0034] The output shaft of the rotary motor is in transmission connection with one end of the stirring shaft after penetrating through the heat recovery tank, so as to drive the stirring shaft to rotate.

[0035] As a preferred technical solution of the present application, a plurality of guide plate groups are arranged on the inner wall of the cavity of the rotary kiln body in the axial direction, each guide plate group comprises a plurality of guide plates located on the same circumference of the rotary kiln body, a plurality of through holes are formed in the guide plates, and each guide plate is arranged in the axial direction of the rotary kiln body.

[0036] A plurality of crushing protrusions are further arranged on the inner wall of the cavity of the rotary kiln body.

[0037] In the present application, the guide plates and the crushing protrusions arranged on the inner wall of the cavity of the rotary kiln body can lift and drop the battery fragments, and increase the acting force of the battery fragments on the crushing protrusions. Preferably, the guide plates are arranged in the upper half of the inner wall of the cavity of the rotary kiln body, so as to avoid the pressure roller.

[0038] The application is provided with a through hole on the guide plate, which enables the battery fragments held by the guide plate to fall from the through hole, thereby achieving the effect of uniformly scattering the materials, so that the materials can be uniformly contacted with the crushing protrusions, thereby ensuring the crushing effect.

[0039] As a preferred technical solution of the application, the driving mechanism comprises a gear ring, a driving motor and a gear, the gear ring is sleeved on the outer periphery of the rotary kiln body and fixed with the rotary kiln body, the output shaft of the driving motor is connected with the gear, the driving motor drives the gear to rotate, and the gear is in meshing transmission with the gear ring.

[0040] As a preferred technical solution of the application, the bottom of the rotary kiln body is further provided with at least two groups of supporting mechanisms, which are respectively located at the two ends of the rotary kiln body, and are used for supporting the rotary kiln body during the rotation of the rotary kiln body.

[0041] The supporting mechanism comprises a supporting ring, a base and a supporting wheel, the supporting ring is sleeved on the outer periphery of the rotary kiln body and movably connected with the rotary kiln body, and the rotary kiln body can freely rotate in the supporting ring; the base is symmetrically arranged on the two sides below the rotary kiln body, the supporting wheel is movably connected on the base, and the supporting wheel is in rolling connection with the supporting ring.

[0042] Exemplarily, the working principle of the rotary kiln with a crushing function for recycling waste lithium batteries provided by the application is as follows:

[0043] The waste lithium batteries are sent into the feeding hopper through the feeding end, fall into the crushing device through the multi-door flap valve, and are crushed by the crushing device to obtain first battery fragments, and the first battery fragments enter the rotary kiln body through the chute.

[0044] The heating device introduces the generated heat into the heating channel, and the outer peripheral area of the rotary kiln body is heated through the heating channel; the gas pump is opened, the heat in the heating channel is extracted through the gas pump, and then injected into the hollow channel of the stirring shaft through the heat recovery tank, and the heat in the hollow channel of the stirring shaft is used to heat the axial central area of the rotary kiln body.

[0045] Nitrogen or low-oxygen waste gas is introduced into the rotary kiln body through the protective gas inlet, and the rotary kiln body rotates under the action of the supporting mechanism and the driving mechanism, so that the waste lithium batteries in the inner cavity of the rotary kiln body are uniformly heated in the protective atmosphere, and the electrolyte in the waste lithium batteries volatilizes after being heated, and is discharged together with the protective gas in the rotary kiln body through the flue gas outlet.

[0046] In the heating process of the battery fragments, the primary battery fragments are secondarily crushed by the stirring device to form secondary battery fragments as the primary battery fragments rotate with the rotary kiln body, and the fragment agglomerates formed by the secondary battery fragments under the action of the binder are crushed and dispersed by the crushing roller; the primary battery fragments pass through each crushing chamber in turn and are crushed in each crushing chamber in turn, and the battery fragments enter the discharge bin after passing through the last crushing chamber, are discharged after cooling in the discharge bin, and are further crushed and sorted at the rear end.

[0047] Compared with the prior art, the rotary kiln has the following beneficial effects:

[0048] The rotary kiln provided by the application is mainly used for recycling crushed waste lithium batteries, and the device mainly comprises a feed hopper, a rotary kiln body and a discharge bin. The battery does not need to be discharged, but is directly sent into the feed hopper through the feeding end, falls into the crushing device through the multi-door flap valve, and the crushing device is in a protective atmosphere of nitrogen / low-oxygen waste gas, so that the crushing safety of the waste lithium battery in the charged state is ensured. The battery fragments after crushing enter the rotary kiln body through the chute, and the waste lithium battery in the rotary kiln body is volatilized after being heated, and is discharged together with the protective gas in the rotary kiln body through the flue gas outlet. The heating time of the rotary kiln body is about 1-2h, and the heating temperature is about -100-600℃. The waste lithium battery after heating enters the discharge bin for cooling, and is further crushed and sorted at the rear end.

[0049] The rotary kiln provided by the application can realize the crushing and high-temperature heat treatment of the waste lithium battery, so that the waste lithium battery can be safely disposed and the electrolyte can be effectively removed, dry battery fragments are obtained, and the further separation and sorting at the rear end are facilitated. The traditional disposal process of the waste lithium battery generally needs to be pretreated by discharging + nitrogen protection crushing, the device can directly realize the crushing of the waste lithium battery under the condition of nitrogen / low-oxygen waste gas, and can perform heating treatment to evaporate the electrolyte, so that the risk and hidden danger of the battery crushing in the charged state are solved, and the process of directly crushing and heat treating the battery to evaporate the electrolyte is realized. BRIEF DESCRIPTION OF DRAWINGS

[0050] Figure 1 The structure schematic view of the rotary kiln provided for one specific embodiment of the application;

[0051] Figure 2 The structure schematic view of the rotary kiln provided for one specific embodiment of the application; Figure 1

[0052] Figure 3 The structure schematic view of the crushing device provided for one specific embodiment of the application;

[0053] Figure 4 The structure schematic view of the stirring device provided for one specific embodiment of the application;

[0054] Figure 5 ​A structural schematic diagram of a driving mechanism provided for a specific embodiment of the present application is shown in the figure;

[0055] Figure 6 A structural schematic diagram of a supporting mechanism provided for a specific embodiment of the present application is shown in the figure;

[0056] Figure 7 A schematic diagram of the arrangement state of a deflector provided for a specific embodiment of the present application is shown in the figure;

[0057] Wherein: 100 - hopper; 110 - flap valve; 120 - crushing device; 121 - first crushing roller; 122 - second crushing roller; 123 - first gear; 124 - second gear; 125 - driving device; 130 - flue gas outlet; 140 - chute; 200 - rotary kiln body; 210 - crushing chamber; 211 - inner layer kiln body; 212 - inner layer heat insulating material; 213 - heating channel; 214 - outer layer kiln body; 215 - outer layer heat insulating material; 216 - first crushing chamber; 217 - second crushing chamber; 218 - third crushing chamber; 219 - deflector; 220 - stirring device; 221 - stirring shaft; 222 - stirring blade; 223 - rotary motor; 224 - heat recovery opening; 230 - partition; 231 - center discharge outlet; 232 - edge material leakage gap; 240 - compression roller; 300 - discharge bin; 310 - buffer chamber; 311 - heat recovery tank; 312 - air pump; 313 - protective gas inlet; 320 - cooling chamber; 321 - discharge outlet; 400 - driving mechanism; 410 - driving motor; 420 - gear ring; 430 - gear; 500 - supporting mechanism; 510 - supporting ring; 520 - base; 530 - carrier wheel. DETAILED DESCRIPTION

[0058] The technical solutions of the present application will be described in detail below with reference to specific embodiments and the accompanying drawings. The embodiments described herein are specific embodiments of the present application, which are used to illustrate the concept of the present application; all the descriptions are explanatory and exemplary, and should not be understood as limiting the embodiments of the present application and the protection scope of the present application. In addition to the embodiments described herein, those skilled in the art can also employ other technical solutions that are obvious based on the disclosure of the claims and the specification of the present application, which include technical solutions that make any obvious substitutions and modifications to the embodiments described herein.

[0059] In a specific embodiment, the present application provides a rotary kiln with crushing function for recycling waste lithium batteries, as shown in the figure, the rotary kiln for recycling waste lithium batteries comprises a hopper 100, a rotary kiln body 200 and a discharge bin 300 connected in sequence along the material flow direction, the rotary kiln body 200 is connected with a driving mechanism 400 (not shown in the figure), and the driving mechanism 400 is used to drive the rotary kiln body 200 to rotate. Figure 1 In a specific embodiment, the present application provides a rotary kiln with crushing function for recycling waste lithium batteries, as shown in the figure, the rotary kiln for recycling waste lithium batteries comprises a hopper 100, a rotary kiln body 200 and a discharge bin 300 connected in sequence along the material flow direction, the rotary kiln body 200 is connected with a driving mechanism 400 (not shown in the figure), and the driving mechanism 400 is used to drive the rotary kiln body 200 to rotate.

[0060] The feed hopper 100 is equipped with at least one flap valve 110 at its inlet end, a crushing device 120 is installed inside the feed hopper 100, and a flue gas outlet 130 is also provided at the top of the feed hopper 100.

[0061] The bottom of the unloading hopper 300 is provided with a discharge port, and the top of the unloading hopper 300 is provided with a protective gas inlet 310. Nitrogen or low-oxygen waste gas is introduced into the rotary kiln body 200 through the protective gas inlet 310.

[0062] The rotary kiln provided by this invention is mainly used for recycling and crushing waste lithium batteries. The equipment mainly consists of a feed hopper 100, a rotary kiln body 200, and a discharge bin 300. Batteries, without needing to be discharged, are directly fed into the feed hopper 100 through the feed end, and fall into the crushing device 120 through multiple flap valves 110. The crushing device 120 is in a protective atmosphere of nitrogen / low-oxygen exhaust gas to ensure the safety of crushing waste lithium batteries while they are charged. The crushed battery fragments enter the rotary kiln body 200 through a chute 140. Inside the rotary kiln body 200, the electrolyte of the waste lithium batteries is evaporated after heating and discharged along with the protective gas inside the rotary kiln body 200 through the flue gas outlet 130. The heating time of the rotary kiln body 200 is approximately 1-2 hours, and the heating temperature is approximately 100-600℃. The heated waste lithium batteries enter the discharge bin 300 for cooling before further crushing and sorting at the downstream end.

[0063] The rotary kiln provided by this invention enables the crushing and high-temperature heat treatment of waste lithium batteries, allowing for safe disposal and effective removal of electrolyte, resulting in dry battery fragments that facilitate further separation and sorting. Traditional waste lithium battery disposal typically requires pretreatment through discharge followed by nitrogen-protected crushing. This equipment can directly crush waste lithium batteries while they are still charged, and then heat-treat them to evaporate the electrolyte under nitrogen / low-oxygen exhaust gas conditions. This eliminates the risks and hazards associated with crushing batteries while they are still charged, enabling the process of directly crushing, heat-treating, and evaporating the electrolyte from intact batteries.

[0064] exist Figure 3 In the embodiment shown, the crushing device 120 includes a first crushing roller 121 and a second crushing roller 122 arranged side by side in a horizontal direction. The first crushing roller 121 and the second crushing roller 122 are engaged by inter-tooth meshing to crush waste lithium batteries.

[0065] One end of the first crushing roller 121 extends to the outside of the feed hopper 100 and is fixedly connected to the first gear 123. One end of the second crushing roller 122 extends to the outside of the feed hopper 100 and is fixedly connected to the second gear 124. The first gear 123 and the second gear 124 are driven by inter-tooth meshing. The end of the first crushing roller 121 extending out of the feed hopper 100 is also connected to a drive device 125, which is used to drive the first crushing roller 121 to rotate.

[0066] As a preferred technical solution of the present invention, the rotary kiln body 200 is inclined, and a plurality of partitions 230 are arranged along the axial direction inside the cavity of the rotary kiln body 200. The partitions 230 divide the inner cavity of the rotary kiln body 200 into a plurality of interconnected crushing chambers 210.

[0067] In one embodiment of the present invention, such as Figure 1 As shown, the rotary kiln body 200 has two partitions 230 arranged along the axial direction inside the cavity, which divide the inner cavity of the rotary kiln body 200 into three interconnected crushing chambers 210, which are the first crushing chamber 216, the second crushing chamber 217 and the third crushing chamber 218 in sequence along the axial direction of the rotary kiln body 200.

[0068] The partition 230 has a central discharge port 231 in the center, and the edge of the partition 230 has several edge leakage gaps 232 arranged circumferentially. The edge leakage gaps 232 are distributed around the central discharge port 231, and the openings of the edge leakage gaps 232 are close to the inner wall of the rotary kiln body 200.

[0069] In this invention, multiple partitions 230 are set to divide the rotary kiln body 200 into multiple crushing chambers 210, thereby realizing multi-stage fine crushing of waste lithium batteries.

[0070] exist Figure 1 In the illustrated embodiment, a stirring device 220 is installed inside the rotary kiln body 200, and the rotation direction of the stirring device 220 is opposite to the rotation direction of the rotary kiln body 200. Figure 4 As shown, the stirring device 220 includes a stirring shaft 221 and a plurality of stirring blades 222 disposed on the stirring shaft 221.

[0071] Each grinding chamber 210 is equipped with at least one stirring blade 222, and the number of stirring blades 222 in different grinding chambers 210 is different; along the material flow direction, the number of stirring blades 222 in each grinding chamber 210 increases step by step.

[0072] In one example of the invention, such as Figure 1 As shown, the first grinding chamber 216 is equipped with two stirring blades 222, the second grinding chamber 217 is equipped with three stirring blades 222, and the third grinding chamber 218 is equipped with four stirring blades 222.

[0073] In the present application, the rotation direction of the rotary kiln body 200 is opposite to the rotation direction of the stirring device 220, and the high-temperature gas in the rotary kiln body 200 generates centrifugal force under the reverse rotation guide, thereby scattering against the inner wall of the rotary kiln body 200, effectively increasing the impact force of the high-temperature gas on the waste lithium battery, achieving the purpose of fully dispersing the waste lithium battery, and also ensuring that the waste lithium battery is fully heated, so that the electrolyte evaporates as soon as possible.

[0074] In the present application, different stirring blades 222 are arranged in different crushing cavities 210, the stirring blades 222 in the crushing cavity 210 near one end of the feed hopper 100 are the least, the stirring blades 222 in the crushing cavity 210 near one end of the discharge bin 300 are the most, and the stirring blades 222 in the middle crushing cavities 210 gradually increase, realizing the step-by-step crushing of the waste lithium battery, which can ensure that the waste lithium battery can be crushed to the required size in the corresponding crushing cavity 210.

[0075] It should be noted that the shape and number of the stirring blades 222 are not specifically required in the present application, which can be flat, circular arc or spiral, etc., and the stirring blades 222 with circular arc structure are preferably adopted, which has better guiding property and can increase the impact force when the hot gas flow hits the inner wall of the rotary kiln body 200.

[0076] In Figure 1 In the embodiment shown in the figure, a press roller 240 is arranged in each crushing cavity 210, the press roller 240 has an axially through hole, the stirring shaft 221 passes through the hole, and the diameter of the stirring shaft 221 is greater than the hole diameter of the hole. Figure 4 As shown in the figure, the press roller 240 is eccentrically arranged between the stirring shaft 221, the axis of the press roller 240 is lower than the axis of the stirring shaft 221 and located directly below the axis of the stirring shaft 221, and the stirring shaft 221 rotates at the same time to drive the press roller 240 to slightly swing, so as to crush the material at the bottom of the crushing cavity 210.

[0077] The weights of the press rollers 240 in different crushing cavities 210 are different; along the material flow direction, the weights of the press rollers 240 in each crushing cavity 210 gradually increase.

[0078] Since the waste lithium battery contains substances with high viscosity such as adhesive, when the waste lithium battery is crushed into fragments by the crushing device 120 and enters the rotary kiln body 200, the battery fragments will agglomerate to form fragment agglomerates under the action of the adhesive in the high-temperature environment in the rotary kiln body 200, and simple mechanical separation by the stirring device 220 cannot realize the disassembly and dispersion of the fragment agglomerates; in addition, even if it can be dispersed, it will be agglomerated again due to the high-temperature environment and the presence of the adhesive.

[0079] During the rotation of the rotary kiln 200, the fragment agglomerates rotate with the kiln. When the fragment agglomerates reach a certain height, due to the slow rotation speed of the rotary kiln 200 and the small centrifugal force, the fragment agglomerates will fall to the bottom of the rotary kiln 200 under the action of gravity. Then, they continue to rotate with the rotary kiln 200, rise to a certain height again, and fall again. The fragment agglomerates repeat the above process continuously within the rotary kiln 200. If no treatment is taken, the fragment agglomerates will be patted and compacted during the continuous lifting and falling process, making the fragment agglomerates increasingly dense and impossible to break up. To this end, the present invention provides a pressure roller 240 in each crushing chamber 210. When the fragment agglomerates fall to the bottom of the rotary kiln body 200 under the action of gravity, they are crushed and dispersed by the pressure roller 240. When the fragment agglomerates rotate to a certain height with the rotary kiln, the temperature of the fragment agglomerates drops due to the lower temperature of the upper layer inside the rotary kiln body 200, which reduces the activity of the binder and causes the fragment agglomerates to solidify slightly, making it easier for the pressure roller 240 to crush them. When the slightly solidified fragment agglomerates fall to the bottom of the rotary kiln body 200 again, the pressure roller 240 crushes the slightly solidified fragment agglomerates again, so that the fragment agglomerates can be further crushed and dispersed. This cycle is repeated until the fragment agglomerates are completely dispersed.

[0080] exist Figure 2 In the embodiment shown, the rotary kiln body 200 includes an inner kiln body 211 and an outer kiln body 214 located on the outer periphery of the inner kiln body 211. An inner layer insulation material 212 is laid between the outer kiln body 214 and the inner kiln body 211, and an outer layer insulation material 215 is laid on the outer wall of the outer kiln body 214.

[0081] A heating channel 213 is provided along the axial direction from the wall thickness of the inner kiln body 211. The end of the heating channel 213 near the feed hopper 100 is the inlet end, and the opposite end is the outlet end. A heating device is connected to the inlet end, and the heat generated by the heating device enters the heating channel 213 to heat the material in the rotary kiln body 200.

[0082] The inner kiln body 211 and the outer kiln body 214 provided by the present invention are constructed by combining precast bricks or irregularly shaped bricks. The inner kiln body 211 has a heating channel 213 that runs through the entire inner kiln body 211 through the brick body. The combustion flame or high-temperature airflow accelerated by the blower system passes through the heating channel 213 at high speed to heat the waste lithium batteries in the rotary kiln body 200.

[0083] The rotary kiln body 200 with a double-layer structure provided by the present invention can isolate the heating source from the waste lithium battery, avoiding contamination of the waste lithium battery by impurities in the heating flame or airflow. By setting the inner insulation material 212 and the outer insulation material 215, the heat transfer efficiency and insulation effect of the waste lithium battery are improved.

[0084] It should be noted that the shape and number of the heating channels 213 are not specifically required and specially limited by the present application, and can be a plurality of mutually parallel heating channels 213 arranged along the circumference of the rotary kiln body 200, the axis of each heating channel 213 being parallel to the axial direction of the rotary kiln body 200. In order to cooperate with the pressure roller 240 to disperse the fragment agglomerates, the number of the heating channels 213 in the upper half of the inner kiln body 211 is less than the number of the heating channels 213 in the lower half, so that the temperature of the upper layer inside the rotary kiln body 200 is lower than the temperature of the lower layer. Of course, the heating channels 213 can also be helical along the axial direction of the rotary kiln body 200. It can be understood that any shape and any number of heating channels 213 fall within the protection scope and disclosure scope of the present application.

[0085] In Figure 1 In the embodiment shown, the discharge bin 300 includes a buffer chamber 310 and a cooling chamber 320 connected in sequence along the material flow direction, and the bottom of the cooling chamber 320 is provided with a discharge port 321.

[0086] The buffer chamber 250 is provided with an air pump 252, a rotary motor 223 and a heat recovery tank 251. The air inlet end of the air pump 252 is communicated with the outlet end of the heating channel 213, and the air pump 252 is used to extract the heat in the heating channel 213 and then send it into the heat recovery tank 251.

[0087] The stirring shaft 221 is of a hollow structure, one end of the stirring shaft 221 extends into the heat recovery tank 251, and a heat recovery port 224 is formed in the side wall of the one end of the stirring shaft 221 extending into the heat recovery tank 251. The recovered heat in the heat recovery tank 251 is injected into the hollow passage of the stirring shaft 221 through the heat recovery port 224.

[0088] The output shaft of the rotary motor 223 is transmissionally connected with one end of the stirring shaft 221 after penetrating through the heat recovery tank 251, so as to drive the stirring shaft 221 to rotate.

[0089] In Figure 7 In the embodiment shown, the inner wall of the cavity of the rotary kiln body 200 is provided with a plurality of guide plate groups along the axial direction, each guide plate group including a plurality of guide plates 219 located on the same circumference of the rotary kiln body 200, a plurality of through holes being formed in each guide plate 219, and each guide plate 219 being arranged along the axial direction of the rotary kiln body 200. The plurality of guide plates 219 included in the adjacent two guide plate groups are distributed in a staggered manner along the axial direction of the rotary kiln body 200.

[0090] The inner wall of the cavity of the rotary kiln body 200 is further provided with a plurality of crushing protrusions.

[0091] In this invention, by providing a guide plate 219 and a crushing protrusion on the inner wall of the rotary kiln body 200, battery fragments can be lifted and thrown down, increasing the interaction force between the battery fragments and the crushing protrusion. Preferably, the guide plate 219 is provided on the upper half of the inner wall of the rotary kiln body 200 to avoid the pressure roller 240.

[0092] The present invention has through holes arranged on the guide plate 219. These through holes allow the battery fragments caught by the guide plate 219 to fall out from the through holes, which has the effect of dispersing and spreading the material evenly, so that the material can contact the crushing protrusions in a dispersed manner, thereby ensuring the crushing effect.

[0093] exist Figure 5 In the embodiment shown, the drive mechanism 400 includes a gear ring 420, a drive motor 410, and a gear 430. The gear ring 420 is sleeved on the outer periphery of the rotary kiln body 200 and fixed to the rotary kiln body 200. The output shaft of the drive motor 410 is connected to the gear 430. The drive motor 410 drives the gear 430 to rotate, and the gear 430 meshes with the gear ring 420 for transmission.

[0094] exist Figure 6 In the embodiment shown, at least two sets of support mechanisms 500 are also provided at the bottom of the rotary kiln body 200, located at both ends of the rotary kiln body 200 respectively, for supporting the rotary kiln body 200 during rotation.

[0095] The support mechanism 500 includes a support ring 510, a base 520, and a support roller 530. The support ring 510 is sleeved on the outer periphery of the rotary kiln body 200 and is movably connected to the rotary kiln body 200. The rotary kiln body 200 can rotate freely within the support ring 510. The base 520 is symmetrically arranged on both sides below the rotary kiln body 200. The support roller 530 is movably connected to the base 520 and is in rolling connection with the support ring 510.

[0096] In another specific embodiment, the working principle of the rotary kiln for recycling waste lithium batteries with crushing function provided by the present invention is as follows:

[0097] Waste lithium batteries are fed into the feed hopper 100 through the feed end, and fall into the crushing device 120 through multiple flap valves 110. The crushing device 120 crushes the waste lithium batteries once to obtain primary battery fragments. The primary battery fragments enter the rotary kiln 200 through the chute 140.

[0098] The heating device guides the generated heat into the heating channel 213, and the outer peripheral area of the rotary kiln body 200 is heated through the heating channel 213; the gas pump 252 is opened, and the heat in the heating channel 213 is extracted and then injected into the hollow channel of the stirring shaft 221 through the heat recovery tank 251, and the axial central area of the rotary kiln body 200 is heated by the heat in the hollow channel of the stirring shaft 221;

[0099] The nitrogen or low-oxygen waste gas is introduced into the rotary kiln body 200 through the protective gas inlet 310, and the rotary kiln body 200 rotates under the action of the support mechanism 500 and the driving mechanism 400, so that the waste lithium batteries in the inner cavity of the rotary kiln body 200 are uniformly heated in a protective atmosphere, and the electrolyte in the waste lithium batteries volatilizes after being heated, and is discharged together with the protective gas in the rotary kiln body 200 through the flue gas outlet 130;

[0100] During the heating process of the battery fragments, the primary battery fragments are secondary crushed by the stirring device 220 to form secondary battery fragments as the primary battery fragments rotate with the rotary kiln body 200, and the fragment agglomerates formed by the secondary battery fragments under the action of the binder are crushed and scattered by the crushing roller 240; the primary battery fragments pass through each crushing chamber 210 in turn and are crushed step by step in each crushing chamber 210, and the battery fragments enter the discharge bin 300 through the last crushing chamber 210, are cooled in the discharge bin 300, and are discharged, for further crushing and sorting at the rear end.

[0101] The applicant declares that the above description is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and those skilled in the art should understand that any changes or replacements within the technical scope disclosed by the present application can be easily thought of by any person skilled in the art, and all fall within the protection scope and disclosure scope of the present application.

Claims

1. A rotary kiln for recycling waste lithium batteries with a crushing function, characterized in that, The rotary kiln for recycling waste lithium batteries comprises, along the material flow direction, a feeding hopper, a rotary kiln body and a discharge bin which are connected in sequence, the rotary kiln body is connected with a driving mechanism for driving the rotary kiln body to rotate; At least one flap valve is arranged at the inlet end of the feeding hopper, a crushing device is arranged inside the feeding hopper, and a flue gas outlet is arranged at the top of the feeding hopper; A discharge opening is arranged at the bottom of the discharge bin, and a protective gas inlet is arranged at the top of the discharge bin, through which nitrogen or low-oxygen waste gas is introduced into the rotary kiln body; The crushing device comprises first and second crushing rollers arranged in parallel in the horizontal direction, the first and second crushing rollers are meshed through the teeth to crush the waste lithium batteries; One end of the first crushing roller extends to the outside of the feeding hopper and is fixedly connected with a first gear, one end of the second crushing roller extends to the outside of the feeding hopper and is fixedly connected with a second gear, the first and second gears are meshed through the teeth to drive, one end of the first crushing roller extending out of the feeding hopper is further connected with a driving device for driving the first crushing roller to rotate; The rotary kiln body is arranged obliquely, a plurality of partitions are arranged in the axial direction inside the cavity of the rotary kiln body, and the partitions divide the inner cavity of the rotary kiln body into a plurality of crushing cavities which are connected with each other; A central discharge opening is arranged at the center of the partition, a plurality of edge material leakage notches are arranged at the edge of the partition in the circumferential direction, the edge material leakage notches are distributed around the central discharge opening, and the opening of the edge material leakage notch is close to the inner wall of the cavity of the rotary kiln body; A stirring device is arranged in the inner cavity of the rotary kiln body, the rotating direction of the stirring device is opposite to the rotating direction of the rotary kiln body; the stirring device comprises a stirring shaft and a plurality of stirring blades arranged on the stirring shaft, At least one stirring blade is arranged in each crushing cavity, and the number of stirring blades arranged in different crushing cavities is different; along the material flow direction, the number of stirring blades in each crushing cavity gradually increases; A press roller is arranged in each crushing cavity, the press roller has an axial through hole, the stirring shaft passes through the through hole, the diameter of the stirring shaft is greater than the hole diameter of the through hole; the press roller and the stirring shaft are arranged eccentrically, the axis of the press roller is lower than the axis of the stirring shaft and is located directly below the axis of the stirring shaft, and the stirring shaft rotates at the same time to drive the press roller to slightly swing to crush the material at the bottom of the crushing cavity; The weights of the press rollers in different crushing cavities are different; Along the material flow direction, the weights of the press rollers in each crushing cavity gradually increase.

2. The rotary kiln for recycling of spent lithium batteries according to claim 1, characterized in that, The rotary kiln body comprises an inner layer kiln body and an outer layer kiln body located at the periphery of the inner layer kiln body, inner layer insulation material is arranged between the outer layer kiln body and the inner layer kiln body, and outer layer insulation material is arranged on the outer wall of the outer layer kiln body; A spiral heating channel is formed in the wall thickness of the inner layer kiln body in the axial direction, one end of the heating channel close to the feeding hopper is an inlet end, and the opposite end is an outlet end; a heating device is connected to the inlet end, and the heating device generates heat into the heating channel to heat the material in the rotary kiln body.

3. The rotary kiln for recycling of spent lithium batteries according to claim 2, characterized in that, The discharge bin includes a buffer chamber and a cooling chamber connected in sequence along the material flow direction, and a discharge port is formed in the bottom of the cooling chamber; The buffer chamber is provided with an air pump, a rotary motor and a heat recovery tank, the air inlet end of the air pump is communicated with the outlet end of the heating channel, and the air pump is used to extract the heat in the heating channel and then send it into the heat recovery tank; The stirring shaft is a hollow structure, one end of the stirring shaft extends into the heat recovery tank, a heat recovery port is formed in the side wall of the end of the stirring shaft extending into the heat recovery tank, and the recovered heat in the heat recovery tank is injected into the hollow channel of the stirring shaft through the heat recovery port; The output shaft of the rotary motor is in transmission connection with one end of the stirring shaft after penetrating through the heat recovery tank, so as to drive the stirring shaft to rotate.

4. The rotary kiln for recycling of spent lithium batteries according to claim 1, characterized in that, A plurality of guide plate groups are arranged on the inner wall of the cavity of the rotary kiln body in the axial direction, each guide plate group includes a plurality of guide plates located on the same circumference of the rotary kiln body, a plurality of through holes are formed in the guide plates, and each guide plate is arranged in the axial direction of the rotary kiln body; the plurality of guide plates included in the adjacent two guide plate groups are distributed in the axial direction of the rotary kiln body in a staggered manner. A plurality of crushing protrusions are arranged on the inner wall of the cavity of the rotary kiln body.

5. The rotary kiln for recycling of spent lithium batteries according to claim 1, characterized in that, The driving mechanism includes a gear ring, a driving motor and a gear, the gear ring is sleeved on the outer circumference of the rotary kiln body and fixed with the rotary kiln body, the output shaft of the driving motor is connected with the gear, the driving motor drives the gear to rotate, and the gear is in meshing transmission with the gear ring.

6. The rotary kiln for recycling of spent lithium batteries according to claim 1, characterized in that, At least two groups of supporting mechanisms are arranged at the two ends of the rotary kiln body respectively, and are used for supporting the rotary kiln body during rotation of the rotary kiln body; The supporting mechanism includes a supporting ring, a base and a supporting wheel, the supporting ring is sleeved on the outer circumference of the rotary kiln body and movably connected with the rotary kiln body, and the rotary kiln body can rotate freely in the supporting ring; the base is symmetrically arranged on the two sides below the rotary kiln body, the supporting wheel is movably connected with the base, and the supporting wheel is in rolling connection with the supporting ring.

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