A multi-stage sorting system and method for waste lithium batteries

Abstract

The present invention relates to a multi-stage sorting system and method for waste lithium batteries, the system comprising a crushing system, a sorting system and a waste gas treatment system; the waste gas treatment system comprising a dust removal device, a cooler, a washing tower and an activated carbon adsorption device; the waste gas treatment system is connected to the crushing system and the sorting system respectively, and the crushing system is connected to the sorting system; the technical scheme of the present invention brings the following beneficial effects: (1) small footprint; (2) recovery rate of electrode powder>98%; (3) recovery rate of copper and aluminum>98%; (4) plastics are recycled; (5) VOC in waste gas<50mg / m 3 ; (6) No dioxin is produced; (7) No wastewater is produced; (8) The electrolytic powder is of high purity.

Description

Technical Field

[0001] The invention belongs to the technical field of waste lithium battery recycling, and in particular relates to a multi-stage sorting system and method for waste lithium batteries. Background Art

[0002] In 2020, the cumulative scrap volume of power lithium batteries in my country will reach 120,000-170,000 tons. The theoretical scrap volume of power lithium batteries will increase from 18.91Gwh in 2020 to 105.3Gwh in 2025. Waste lithium batteries contain metals and organic matter such as cobalt, nickel, manganese, lithium, iron and aluminum. The average content of lithium in ternary batteries is 1.9%, nickel is 9%, cobalt is 3%, manganese is 4%, copper is 13.3%, aluminum is 12.7%, etc. If waste lithium batteries are not recycled, they will cause great threats and pollution to the environment, and it is also a waste of resources.

[0003] Currently, there are two main technologies for recycling waste lithium batteries: (1) pyrometallurgical recycling process; (2) wet recycling process.

[0004] Foreign companies mainly use pyrometallurgical recycling technology, which is to treat waste lithium-ion batteries by reduction roasting. High-temperature metallurgical methods are used to recycle waste lithium-ion batteries through special furnaces. This process puts the battery and packaging into a smelting furnace for roasting, and no pretreatment is required before roasting. At the same time, the energy released by the combustion of graphite and organic solvents can be used to obtain a mixture of metals such as cobalt and nickel, realizing the recycling of metals. The disadvantages of the pyrometallurgical process are: high energy consumption, the electrolyte solution and other components in the electrode will be converted into harmful components such as hydrofluoric acid or phosphorus pentoxide after combustion, and a large amount of waste gas will be generated, which will increase the cost of tail gas treatment and easily cause air pollution.

[0005] Domestic companies mainly use wet recycling technology, which is to disassemble and pre-treat the waste batteries and dissolve them in acid and alkali solutions to extract some valuable metal elements, and then use ion exchange and electrodeposition to extract the remaining valuable metals. Disadvantages: slow reaction speed, small material throughput, complex process, high cost, and low value of recycled products. Summary of the invention

[0006] In view of the defects existing in the prior art, the purpose of the present invention is to provide a multi-stage sorting system and method for waste lithium batteries to achieve the following objectives:

[0007] (1) Recover electrode powder from waste lithium batteries and increase the recovery rate of electrode powder;

[0008] (2) No discharge treatment is required;

[0009] (3) Recycling copper, aluminum and plastic from used lithium batteries;

[0010] (4) Mechanical stripping of electrode powder and binder.

[0011] (5) Improve the recovery rate of copper and aluminum.

[0012] (6) Avoid the generation of wastewater.

[0013] (7) Reduce impurities in electrode powder and improve the purity of electrode powder.

[0014] In order to achieve the above purpose, the technical solution adopted by the present invention is:

[0015] A multi-stage sorting system for waste lithium batteries, comprising: a crushing system, a sorting system and an exhaust gas treatment system;

[0016] The exhaust gas treatment system includes: a dust removal device, a cooler, a washing tower and an activated carbon adsorption device;

[0017] The exhaust gas treatment system is connected to the crushing system and the sorting system respectively, and the crushing system is connected to the sorting system;

[0018] The modules or cells of waste lithium batteries enter the crushing system via a belt conveyor;

[0019] The crushing system comprises: a coarse crusher, a fine crusher, a buffer box and a quantitative feeder;

[0020] The coarse crusher is connected to the fine crusher through a screw conveyor. The coarse crusher is used to crush the module and send the crushed materials into the fine crusher, and at the same time, send the waste gas volatilized by the electrolyte into the condenser; the fine crusher is used to crush the battery core and the materials sent by the coarse crusher, and send the crushed materials into the buffer box, and at the same time, send the waste gas volatilized by the electrolyte into the condenser. A quantitative feeder is provided at the bottom of the buffer box;

[0021] The separation system comprises: a primary screening device, a filtering device, a grinding device, a secondary screening device, an air separation device I, an air separation device II, an air separation device III, a primary magnetic separation device, a secondary magnetic separation device and an eddy current separation device;

[0022] The primary screening device is connected to the filtering device, the filtering device is respectively connected to the primary magnetic separation device and the grinding device, the grinding device is connected to the secondary screening device, the primary magnetic separation device is connected to the secondary magnetic separation device, the secondary magnetic separation device is connected to the eddy current separation device, the secondary screening device is respectively connected to the air separation device I and the air separation device II, and the air separation device II is connected to the air separation device III;

[0023] The buffer box conveys the crushed material into a primary screening device through a screw conveyor, and the primary screening device is used to separate the electrode powder from the crushed material. The remaining material enters a filtering device, and the filtering device is used to separate the remaining material into a light component and a heavy component. The heavy component enters a primary magnetic separation device, and the primary magnetic separation device is used to separate the iron from the heavy component. The remaining component enters a secondary magnetic separation device, and the secondary magnetic separation device is used to separate the iron from the remaining component. The components processed by the secondary magnetic separation device enter an eddy current separation device, and the eddy current separation device is used to separate the copper and aluminum from the components.

[0024] The light component enters a grinding device, which is used to mechanically peel the electrode powder from the copper foil or the aluminum foil to obtain a mixture of electrode powder, copper foil, aluminum foil and plastic. The mixture enters a secondary screening device, which is used to separate the electrode powder from the mixture. The remaining mixture enters an air separation device I and an air separation device II, where the air separation device I is used to separate copper and aluminum, and the air separation device II is used to separate plastic. The material processed by the air separation device II enters an air separation device III, which is used to separate copper and aluminum.

[0025] On the basis of the above scheme, a rain cover is provided above the belt conveyor, and the belt conveyor is provided with a wire protection device.

[0026] On the basis of the above scheme, the coarse crusher and the fine crusher work under nitrogen protection.

[0027] Based on the above solution, the particle size of the material after being crushed by the fine crusher is less than 20 mm.

[0028] On the basis of the above scheme, the condenser is connected to the washing tower, and the washing tower is connected to the activated carbon adsorption device. The condenser is used to condense the condensable waste gas in the waste gas, and the condensable waste gas is condensed to form an electrolyte. Other non-condensable waste gas enters the washing tower. The washing tower is used to absorb the HF gas in the non-condensable waste gas. The activated carbon adsorption device is used to adsorb the non-condensable waste gas treated by the washing tower, so that the VOC in the treated waste gas is less than 50mg / m 3 .

[0029] On the basis of the above scheme, the dust removal device includes: a fan, a bag dust removal device and a chimney. The fan is connected to the bag dust removal device through a pipeline, and the bag dust removal device is connected to the chimney through a pipeline. The bag dust removal device is used to remove dust generated in the crushing system and the sorting system. The bag dust removal device has water and oil repellency to prevent moisture and oil from clogging the bags.

[0030] A multi-stage sorting method for waste lithium batteries, using the above multi-stage sorting system, specifically comprises the following steps:

[0031] Step 1: Send the modules or cells of waste lithium batteries into the crushing system;

[0032] Step 2: The module is crushed by the coarse crusher in the crushing system. The exhaust gas generated during the crushing process enters the condenser. The crushed materials enter the fine crusher. The battery cells and the crushed materials are crushed by the fine crusher in the crushing system. The exhaust gas generated during the crushing process enters the condenser. The materials crushed by the fine crusher enter the primary screening device.

[0033] Step 3: After the exhaust gas is treated by the condenser, the condensable exhaust gas in the exhaust gas is condensed to form an electrolyte, and the other non-condensable exhaust gas enters the scrubber for treatment. The scrubber absorbs the HF gas in the non-condensable exhaust gas, and then enters the activated carbon adsorption device for adsorption treatment, so that the VOC in the treated exhaust gas is less than 50mg / m 3 ;

[0034] Step 4: After the crushed material is processed by a primary screening device, the electrode powder is separated, and the remaining material enters a filtering device for processing. After being processed by the filtering device, the light component and the heavy component are separated. The heavy component enters a primary magnetic separation device, and iron is separated after being processed by the primary magnetic separation device. The remaining components enter a secondary magnetic separation device, and iron is separated after being processed by the secondary magnetic separation device. Then, the material is processed by an eddy current separation device, and finally copper and aluminum conductive substances are separated;

[0035] Step 5, the light component enters the grinding device, and after being processed by the grinding device, a mixture of electrode powder, copper foil, aluminum foil and plastic is obtained. The mixture enters the secondary screening device for processing. After being processed by the secondary screening device, the electrode powder is separated, and the remaining mixture enters the air separation device I and the air separation device II. The remaining mixture is processed by the air separation device I to separate copper and aluminum, and the remaining mixture is processed by the air separation device II to separate plastic, and then processed by the air separation device III to finally separate copper and aluminum;

[0036] Step 6: Use dust removal equipment to deal with the dust generated during the crushing and sorting processes.

[0037] Beneficial effects brought by the technical solution of the present invention:

[0038] (1) Small footprint;

[0039] (2) The recovery rate of electrode powder is greater than 98%;

[0040] (3) The recovery rate of copper and aluminum is greater than 98%;

[0041] (4) Plastics were recycled;

[0042] (5) VOC in exhaust gas <50mg / m 3;

[0043] (6) No dioxin production;

[0044] (7) No wastewater is generated;

[0045] (8) The electrode powder is of high purity. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The present invention has the following accompanying drawings:

[0047] Figure 1 The system structure of the present invention is shown in FIG. Figure 1 .

[0048] Figure 2 The system structure of the present invention is shown in FIG. Figure 2 . DETAILED DESCRIPTION

[0049] The following is combined with Figure 1-2 The present invention is described in further detail.

[0050] A multi-stage sorting system for waste lithium batteries, comprising: a crushing system, a sorting system and an exhaust gas treatment system;

[0051] The exhaust gas treatment system includes: a dust removal device, a cooler, a washing tower and an activated carbon adsorption device;

[0052] The exhaust gas treatment system is connected to the crushing system and the sorting system respectively, and the crushing system is connected to the sorting system;

[0053] The modules or cells of waste lithium batteries enter the crushing system via a belt conveyor;

[0054] The crushing system comprises: a coarse crusher, a fine crusher, a buffer box and a quantitative feeder;

[0055] The coarse crusher is connected to the fine crusher through a screw conveyor. The coarse crusher is used to crush the module and send the crushed materials into the fine crusher, and at the same time, send the waste gas volatilized by the electrolyte into the condenser; the fine crusher is used to crush the battery core and the materials sent by the coarse crusher, and send the crushed materials into the buffer box, and at the same time, send the waste gas volatilized by the electrolyte into the condenser. A quantitative feeder is provided at the bottom of the buffer box;

[0056] The separation system comprises: a primary screening device, a filtering device, a grinding device, a secondary screening device, an air separation device I, an air separation device II, an air separation device III, a primary magnetic separation device, a secondary magnetic separation device and an eddy current separation device;

[0057] The primary screening device is connected to the filtering device, the filtering device is respectively connected to the primary magnetic separation device and the grinding device, the grinding device is connected to the secondary screening device, the primary magnetic separation device is connected to the secondary magnetic separation device, the secondary magnetic separation device is connected to the eddy current separation device, the secondary screening device is respectively connected to the air separation device I and the air separation device II, and the air separation device II is connected to the air separation device III;

[0058] The buffer box conveys the crushed material into a primary screening device through a screw conveyor, and the primary screening device is used to separate the electrode powder from the crushed material. The remaining material enters a filtering device, and the filtering device is used to separate the remaining material into a light component and a heavy component. The heavy component enters a primary magnetic separation device, and the primary magnetic separation device is used to separate the iron from the heavy component. The remaining component enters a secondary magnetic separation device, and the secondary magnetic separation device is used to separate the iron from the remaining component. The components processed by the secondary magnetic separation device enter an eddy current separation device, and the eddy current separation device is used to separate the copper and aluminum from the components.

[0059] The light component enters a grinding device, which is used to mechanically peel the electrode powder from the copper foil or the aluminum foil to obtain a mixture of electrode powder, copper foil, aluminum foil and plastic. The mixture enters a secondary screening device, which is used to separate the electrode powder from the mixture. The remaining mixture enters an air separation device I and an air separation device II, where the air separation device I is used to separate copper and aluminum, and the air separation device II is used to separate plastic. The material processed by the air separation device II enters an air separation device III, which is used to separate copper and aluminum.

[0060] On the basis of the above scheme, a rain cover is provided above the belt conveyor, and the belt conveyor is provided with a wire protection device.

[0061] On the basis of the above scheme, the coarse crusher and the fine crusher work under nitrogen protection.

[0062] Based on the above solution, the particle size of the material after being crushed by the fine crusher is less than 20 mm.

[0063] On the basis of the above scheme, the condenser is connected to the washing tower, and the washing tower is connected to the activated carbon adsorption device. The condenser is used to condense the condensable waste gas in the waste gas, and the condensable waste gas is condensed to form an electrolyte. Other non-condensable waste gas enters the washing tower. The washing tower is used to absorb the HF gas in the non-condensable waste gas. The activated carbon adsorption device is used to adsorb the non-condensable waste gas treated by the washing tower, so that the VOC in the treated waste gas is less than 50mg / m 3 .

[0064] On the basis of the above scheme, the dust removal device includes: a fan, a bag dust removal device and a chimney. The fan is connected to the bag dust removal device through a pipeline, and the bag dust removal device is connected to the chimney through a pipeline. The bag dust removal device is used to remove dust generated in the crushing system and the sorting system. The bag dust removal device has water and oil repellency to prevent moisture and oil from clogging the bags.

[0065] A multi-stage sorting method for waste lithium batteries, using the above multi-stage sorting system, specifically comprises the following steps:

[0066] Step 1: Send the modules or cells of waste lithium batteries into the crushing system;

[0067] Step 2: The module is crushed by the coarse crusher in the crushing system. The exhaust gas generated during the crushing process enters the condenser. The crushed materials enter the fine crusher. The battery cells and the crushed materials are crushed by the fine crusher in the crushing system. The exhaust gas generated during the crushing process enters the condenser. The materials crushed by the fine crusher enter the primary screening device.

[0068] Step 3: After the exhaust gas is treated by the condenser, the condensable exhaust gas in the exhaust gas is condensed to form an electrolyte, and the other non-condensable exhaust gas enters the scrubber for treatment. The scrubber absorbs the HF gas in the non-condensable exhaust gas, and then enters the activated carbon adsorption device for adsorption treatment, so that the VOC in the treated exhaust gas is less than 50mg / m 3 ;

[0069] Step 4: After the crushed material is processed by a primary screening device, the electrode powder is separated, and the remaining material enters a filtering device for processing. After being processed by the filtering device, the light component and the heavy component are separated. The heavy component enters a primary magnetic separation device, and iron is separated after being processed by the primary magnetic separation device. The remaining components enter a secondary magnetic separation device, and iron is separated after being processed by the secondary magnetic separation device. Then, the material is processed by an eddy current separation device, and finally copper and aluminum conductive substances are separated;

[0070] Step 5, the light component enters the grinding device, and after being processed by the grinding device, a mixture of electrode powder, copper foil, aluminum foil and plastic is obtained. The mixture enters the secondary screening device for processing. After being processed by the secondary screening device, the electrode powder is separated, and the remaining mixture enters the air separation device I and the air separation device II. The remaining mixture is processed by the air separation device I to separate copper and aluminum, and the remaining mixture is processed by the air separation device II to separate plastic, and then processed by the air separation device III to finally separate copper and aluminum;

[0071] Step 6: Use dust removal equipment to deal with the dust generated during the crushing and sorting processes.

[0072] The key technical points and the points to be protected of the present invention are:

[0073] (1) Process system;

[0074] (2) The particle size of finely crushed materials is less than 20 mm;

[0075] (3) Mechanical separation of binders.

[0076] The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field.

Claims

1. A multi-stage sorting system for waste lithium batteries, characterized in that: include: Crushing system, sorting system and waste gas treatment system; The exhaust gas treatment system includes: a dust removal device, a cooler, a washing tower and an activated carbon adsorption device; The exhaust gas treatment system is connected to the crushing system and the sorting system respectively, and the crushing system is connected to the sorting system; The modules or cells of waste lithium batteries enter the crushing system via a belt conveyor; The crushing system comprises: a coarse crusher, a fine crusher, a buffer box and a quantitative feeder; The coarse crusher is connected to the fine crusher through a screw conveyor. The coarse crusher is used to crush the module and send the crushed materials into the fine crusher, and at the same time, send the waste gas volatilized by the electrolyte into the condenser; the fine crusher is used to crush the battery core and the materials sent by the coarse crusher, and send the crushed materials into the buffer box, and at the same time, send the waste gas volatilized by the electrolyte into the condenser. A quantitative feeder is provided at the bottom of the buffer box; The separation system comprises: a primary screening device, a filtering device, a grinding device, a secondary screening device, an air separation device I, an air separation device II, an air separation device III, a primary magnetic separation device, a secondary magnetic separation device and an eddy current separation device; The primary screening device is connected to the filtering device, the filtering device is respectively connected to the primary magnetic separation device and the grinding device, the grinding device is connected to the secondary screening device, the primary magnetic separation device is connected to the secondary magnetic separation device, the secondary magnetic separation device is connected to the eddy current separation device, the secondary screening device is respectively connected to the air separation device I and the air separation device II, and the air separation device II is connected to the air separation device III; The buffer box conveys the crushed material into a primary screening device through a screw conveyor, and the primary screening device is used to separate the electrode powder from the crushed material. The remaining material enters a filtering device, and the filtering device is used to separate the remaining material into a light component and a heavy component. The heavy component enters a primary magnetic separation device, and the primary magnetic separation device is used to separate the iron from the heavy component. The remaining component enters a secondary magnetic separation device, and the secondary magnetic separation device is used to separate the iron from the remaining component. The components processed by the secondary magnetic separation device enter an eddy current separation device, and the eddy current separation device is used to separate the copper and aluminum from the components. The light component enters a grinding device, which is used to mechanically peel the electrode powder from the copper foil or aluminum foil to obtain a mixture of electrode powder, copper foil, aluminum foil and plastic. The mixture enters a secondary screening device, which is used to separate the electrode powder from the mixture. The remaining mixture enters an air separation device I and an air separation device II, where the air separation device I is used to separate copper and aluminum, and the air separation device II is used to separate plastic. The material processed by the air separation device II enters an air separation device III, which is used to separate copper and aluminum. The condenser is connected to the washing tower, and the washing tower is connected to the activated carbon adsorption device. The condenser is used to condense the condensable waste gas in the waste gas, and the condensable waste gas forms an electrolyte after condensation. Other non-condensable waste gas enters the washing tower. The washing tower is used to absorb the HF gas in the non-condensable waste gas. The activated carbon adsorption device is used to adsorb the non-condensable waste gas treated by the washing tower, so that the VOC in the treated waste gas is less than 50mg / m 3 ; The dust removal device includes: a fan, a bag dust removal device and a chimney. The fan is connected to the bag dust removal device through a pipeline, and the bag dust removal device is connected to the chimney through a pipeline. The bag dust removal device is used to remove dust generated in the crushing system and the sorting system. The bag dust removal device has water-repellent and oil-proof effects to prevent moisture and oil from clogging the bags.

2. The multi-stage sorting system for waste lithium batteries according to claim 1, characterized in that: A rain cover is arranged above the belt conveyor, and the belt conveyor is provided with a wire protection device.

3. The multi-stage sorting system for waste lithium batteries according to claim 1, characterized in that: The coarse crusher and the fine crusher work under nitrogen protection.

4. The multi-stage sorting system for waste lithium batteries according to claim 1, characterized in that: The particle size of the material after being crushed by the fine crusher is less than 20 mm.

5. A method for multi-stage sorting of waste lithium batteries, using the multi-stage sorting system described in any one of claims 1 to 4, specifically comprising the following steps: Step 1: Send the modules or cells of waste lithium batteries into the crushing system; Step 2: The module is crushed by the coarse crusher in the crushing system. The exhaust gas generated during the crushing process enters the condenser. The crushed materials enter the fine crusher. The battery cells and the crushed materials are crushed by the fine crusher in the crushing system. The exhaust gas generated during the crushing process enters the condenser. The materials crushed by the fine crusher enter the primary screening device. Step 3: After the exhaust gas is treated by the condenser, the condensable exhaust gas in the exhaust gas is condensed to form an electrolyte, and the other non-condensable exhaust gas enters the scrubber for treatment. The scrubber absorbs the HF gas in the non-condensable exhaust gas, and then enters the activated carbon adsorption device for adsorption treatment, so that the VOC in the treated exhaust gas is less than 50mg / m 3 ; Step 4: After the crushed material is processed by a primary screening device, the electrode powder is separated, and the remaining material enters a filtering device for processing. After being processed by the filtering device, the light component and the heavy component are separated. The heavy component enters a primary magnetic separation device, and iron is separated after being processed by the primary magnetic separation device. The remaining components enter a secondary magnetic separation device, and iron is separated after being processed by the secondary magnetic separation device. Then, the material is processed by an eddy current separation device, and finally copper and aluminum conductive substances are separated; Step 5, the light component enters the grinding device, and after being processed by the grinding device, a mixture of electrode powder, copper foil, aluminum foil and plastic is obtained. The mixture enters the secondary screening device for processing. After being processed by the secondary screening device, the electrode powder is separated, and the remaining mixture enters the air separation device I and the air separation device II. The remaining mixture is processed by the air separation device I to separate copper and aluminum, and the remaining mixture is processed by the air separation device II to separate plastic, and then processed by the air separation device III to finally separate copper and aluminum; Step 6: Use dust removal equipment to deal with the dust generated during the crushing and sorting processes.

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