A system for disposing of waste lithium batteries

Abstract

This utility model discloses a waste lithium battery disposal system, comprising, in sequence: a pretreatment system; a carbonization system; a black powder controlled lithium extraction system; a black powder wet molding system; and a molded block gasification and melting system. This invention fully utilizes the advantages of pyrometallurgical and hydrometallurgical processes, separating battery black powder and recyclable metals from waste lithium batteries after discharge, crushing, and carbonization. Then, lithium in the black powder is recovered through controlled leaching, and the remaining black powder and other harmful elements are smelted at high temperatures to obtain slag and alloys. This allows for the comprehensive recovery of various resources from waste lithium batteries in a simple process.

Description

Technical Field

[0001] This utility model relates to the field of waste battery treatment, specifically to a waste lithium battery disposal system. Background Technology

[0002] With the booming development of the electric vehicle industry, a large number of used lithium-ion batteries from electric vehicles will enter the recycling market. If these used lithium-ion batteries are not disposed of effectively and safely, the harmful heavy metals and organic electrolytes within them will cause serious environmental pollution, becoming a "last mile" problem hindering the rapid development of new energy vehicles. At the same time, used lithium-ion batteries have high economic value, especially ternary lithium batteries, which contain a large number of valuable metal components such as cobalt, nickel, copper, manganese, and lithium, all with higher metal grades than those found in natural ores. Therefore, the efficient recycling and safe disposal of valuable materials from used lithium batteries, especially ternary lithium batteries, has significant economic and environmental implications.

[0003] Currently, there are two main recycling processes for waste lithium batteries: pyrometallurgical and hydrometallurgical. Pyrometallurgical is the most mature technology, capable of processing different types of waste lithium-ion batteries. It features simple battery pretreatment, a short recycling process, and high throughput. However, pyrometallurgical processes can only recover elements such as nickel, cobalt, and copper, while the crucial lithium element is dispersed in the slag and flue gas, making effective recovery difficult. Furthermore, pyrometallurgical treatment requires high temperatures; direct pyrometallurgical treatment without prior sorting leads to high energy consumption and poor economic efficiency. Hydrometallurgical processes require strict classification and screening of waste lithium batteries and consume large amounts of acid / alkali to separately extract and separate different metals. This process is cumbersome, demands high-end equipment, places significant environmental pressure on the industry, and incurs high operating costs. Summary of the Invention

[0004] Purpose of the utility model: This utility model provides a waste lithium battery disposal system that fully utilizes the advantages of pyrometallurgical and hydrometallurgical processes. After discharging, crushing, and carbonizing the waste lithium batteries, the system separates the battery black powder and recyclable metals from the black powder. Then, the lithium in the black powder is recovered through controlled leaching. The remaining black powder and other harmful elements are then smelted at high temperature to obtain slag and alloys. This allows for the comprehensive recovery of various resources from waste lithium batteries, and the process is simple.

[0005] Technical solution: The waste lithium battery disposal system provided by this utility model includes, in sequence:

[0006] Preprocessing system;

[0007] Carbonization system;

[0008] Lithium extraction system for black powder control;

[0009] Black powder wet forming system;

[0010] Molded block gasification and melting system.

[0011] Furthermore, the pretreatment system includes a brine discharge device, a coarse crushing device, and a fine crushing device arranged in sequence.

[0012] Furthermore, the carbonization system includes: a rotary pyrolysis machine, a hot blast furnace, a flue gas heat exchanger, and a drum screen, a water washing device, a magnetic separation device, and a vortex separation device for the carbonization slag sorting system.

[0013] The rotary pyrolysis machine includes a kiln head, a kiln body, and a kiln tail.

[0014] The kiln head is equipped with a kiln head feed inlet, which is connected to the pretreatment system;

[0015] The kiln body includes a high-temperature flue gas annular channel, a pyrolysis chamber, a spiral baffle in the pyrolysis chamber, and a high-temperature flue gas inlet and a medium-temperature flue gas outlet connected to the high-temperature flue gas annular channel; the high-temperature flue gas inlet is connected to the hot blast stove outlet, and the medium-temperature flue gas outlet is connected to the flue gas heat exchanger.

[0016] The kiln tail is provided with a pyrolysis oil and gas outlet and a pyrolysis solid slag outlet; the pyrolysis oil and gas outlet is connected to the hot blast furnace inlet, and the pyrolysis solid slag outlet is connected in sequence to a drum screen, a water washing device, a magnetic separation device, and a vortex separation device.

[0017] Furthermore, the hot blast stove includes a pyrolysis oil and gas inlet, a crude syngas inlet, an independent burner, a primary air inlet, a circulating air inlet, and a high-temperature flue gas outlet;

[0018] The hot air furnace is vertically divided into an upper combustion chamber and a lower heat exchange chamber;

[0019] The connection between the combustion chamber and the heat exchange chamber is narrowed, and staggered baffles are provided inside the combustion chamber.

[0020] The pyrolysis oil and gas inlet and the crude syngas inlet are respectively connected to the pyrolysis oil and gas outlet and the crude syngas outlet of the shaped block gasification and melting system. The pyrolysis oil and gas inlet and the crude syngas inlet merge and enter the hot blast furnace together.

[0021] The independent burners are distributed around the perimeter of the hot blast stove;

[0022] The primary air inlets are distributed around the pyrolysis oil and gas inlet and the crude syngas inlet;

[0023] The circulating air inlet is located at the bottom of the combustion chamber; the high-temperature flue gas outlet is connected to the high-temperature flue gas inlet.

[0024] The flue gas heat exchanger includes a medium-temperature flue gas inlet, a cold flue gas outlet, a cold air inlet, and a heat-exchanged air outlet. The medium-temperature flue gas exchanges heat with the cold air and enters the hot air furnace as primary air and circulating air. The waste gas generated in the pretreatment system is mixed as primary air.

[0025] Furthermore, the black powder controlled lithium extraction system includes a black powder feeder, a dosing device, a reaction tank, a solid-liquid separation device, a lithium precipitation filtration device, and an auxiliary control system connected in sequence.

[0026] The black powder generated by the carbonization system is fed into the system by a black powder feeder. The lithium precipitation and filtration device includes a lithium precipitation tank, a sodium carbonate dosing device, and a lithium carbonate filtration device.

[0027] Furthermore, the black powder wet forming system includes a material mixer, forming equipment, drying chamber and storage chamber connected in sequence; the material mixer is connected to the solid slag outlet of the black powder controlled lithium extraction system and the feeding device of auxiliary additives through a conveying device.

[0028] The drying chamber is provided with an air inlet and an air outlet. The air inlet is connected to the cold flue gas produced in the carbonization system, and the air outlet is connected to the exhaust gas purification system.

[0029] The exhaust gas purification system includes a lime slurry spraying device, an activated carbon injection device, a cyclone dust collector, a bag filter, an activated carbon filter, and a chimney connected in sequence; the fly ash and solid slag generated by the purification system are all sent to the shaped block gasification and melting system.

[0030] Furthermore, the shaped block gasification and melting system includes a gasification and melting furnace;

[0031] The gasification-melting furnace is divided into a gasification section and a melting section;

[0032] The upper end of the gasification section is provided with a gasification feed inlet and a crude syngas outlet;

[0033] An oxygen-enriched air inlet is provided at the lower end of the gasification section where it connects with the melting section;

[0034] The melting section is equipped with a plasma torch, a slag outlet, and a metal alloy outlet;

[0035] The molten section is inverted trapezoidal in shape;

[0036] The gasification inlet is connected to the black powder wet forming system; the crude syngas outlet is equipped with a gas sampling and analysis device; the slag outlet and the metal alloy outlet are respectively connected to their corresponding slag collection containers.

[0037] Furthermore, the slag outlet is located below the plasma torch and above the metal alloy outlet; the slag and alloy are intermittently discharged after stratification based on their different densities.

[0038] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0039] (1) By combining the carbonization system and the gasification melting system, the process complexity of metal material recycling in lithium batteries is simplified. The carbonization system sorts and recycles other metals besides black powder, while the metals in the black powder are first extracted by controlled leaching and then recycled by high-temperature gasification melting. This not only achieves the environmental friendliness of the entire metal material recycling process of lithium batteries, but also avoids the high energy consumption required for all materials to enter the melting furnace, thus reducing the disposal cost.

[0040] (2) The carbonization system optimizes the structure of the hot blast stove and the design of the system pipeline, ensuring the smooth delivery and complete combustion of crude syngas and pyrolysis oil and gas, which not only ensures the stability of the system operation but also improves the system thermal efficiency.

[0041] (3) The wet lithium extraction system for black powder controls the recovery of lithium by controlling the type of leaching solution and leaching conditions. This solves the problem that lithium cannot be recovered after entering the gasification and melting system or is mixed in the flue ash and has low recovery efficiency. At the same time, it avoids the process complexity of traditional wet extraction of nickel, cobalt and manganese, and realizes the recovery rate and purity of heavy metals such as nickel, cobalt and manganese in the melting furnace.

[0042] (4) By using the black powder forming system, the black powder after lithium extraction is wet-formed with coal powder / carbon powder and binder. This not only eliminates the drying process required for direct black powder forming, but also ensures the calorific value requirements of the subsequent gasification and melting system, greatly reduces the energy consumption of the plasma torch, and provides a strong reducing environment for the system, thereby improving the purity of the metal alloy.

[0043] (4) By setting an oxygen-enriched air inlet at the intersection of the gasification section and the melting section of the gasification melting furnace, and adjusting the oxygen-enriched air flow rate in conjunction with the crude syngas composition, the reducing atmosphere in the gasification melting furnace can be effectively controlled, reducing metal elements such as nickel, cobalt and manganese to their elemental state. At the same time, it is conducive to the full gasification of black powder forming blocks, generating high-value-added crude syngas, and increasing the temperature of the melting section. Attached Figure Description

[0044] Figure 1 This is a flowchart illustrating the overall operation of this utility model.

[0045] Figure 2 This is a schematic diagram of the carbonization system structure of this utility model;

[0046] Figure 3 This is a schematic diagram of the hot air furnace structure of this utility model;

[0047] Figure 4 This is a schematic diagram of the gasification and melting system for the molded block of this utility model. Detailed Implementation

[0048] The present invention will be further described below with reference to the accompanying drawings and embodiments. Example

[0049] like Figure 1 The disposal of used lithium batteries, as shown, includes the following steps:

[0050] Step 1: Pre-treatment of waste lithium batteries.

[0051] Preprocessing system 1 is used.

[0052] The pretreatment system 1 for waste lithium batteries includes a brine discharge device, a waste battery coarse crushing device, and a fine crushing device connected in sequence.

[0053] The brine discharge device consists of an immersion tank filled with sodium sulfate solution and protected by a fiberglass partition bottom plate for corrosion and leakage prevention, along with its supporting solution preparation device and inlet / outlet water pumps; the battery coarse crushing device is a twin-shaft shear crusher or hammer crusher, which performs primary crushing and separation of the battery casing, while also rapidly releasing any residual charge in the battery cells to ensure the safety of subsequent processes; the battery fine crushing device is a single-shaft shredder equipped with an overload protection system, which rapidly crushes the battery until the battery fragments reach the specified requirements and then leak out through the screen.

[0054] The brine discharge device uses a grab bucket for feeding and discharging; the coarse crusher and the fine crusher are connected by a closed belt conveyor;

[0055] Waste lithium batteries are first safely discharged in brine and then sent to a two-stage crushing system to crush them to 30mm. The brine discharge solution used is 5% sodium sulfate brine, the discharge pressure is atmospheric pressure, and the discharge time is 72 hours. During the operation of the crushing system, waste gas containing particulate matter, non-methane total hydrocarbons, PF5 or HF will be generated. This waste gas needs to be sealed and collected before being used as primary air in the hot blast furnace for combustion.

[0056] Step 2: Carbonization of waste lithium batteries.

[0057] Carbonization system 2 is adopted.

[0058] like Figure 2 As shown, the carbonization system 2 for waste lithium batteries includes a rotary pyrolysis machine 2-1, a hot air furnace 2-2, a flue gas heat exchanger 2-3, and a drum screen 2-4, a water washing device 2-5, a magnetic separation device 2-6, and a vortex separation device 2-7 for the carbonization slag sorting system.

[0059] The rotary pyrolysis machine 2-1 includes a kiln head 211, a kiln body 212, and a kiln tail 213.

[0060] The kiln head is equipped with a kiln head feed inlet 211a.

[0061] The kiln body is a double-layer design, including a high-temperature flue gas annular channel 212a, a pyrolysis chamber 212b, a spiral baffle 212c inside the pyrolysis chamber, and a high-temperature flue gas inlet 212d and a medium-temperature flue gas outlet 212e connected to the annular channel.

[0062] The kiln tail is equipped with a pyrolysis oil and gas outlet 213a and a pyrolysis solid slag outlet 213b.

[0063] The kiln head feed inlet 211a is connected to the fine crushing device outlet of the pretreatment system 1 via a sealed screw feeder; the high-temperature flue gas inlet 212d is connected to the high-temperature flue gas outlet 226 of the hot blast stove.

[0064] The pyrolysis solid slag outlet 213b at the kiln tail is connected in sequence to a drum screen 2-4, a water washing device 2-5, a magnetic separation device 2-6, and a vortex separation device 2-7, so as to separate black powder from iron, copper and aluminum in the pyrolysis solid slag, and to clean and recover the resource materials respectively.

[0065] Steel balls connected by steel ropes are installed inside the drum screen 2-4. As the drum screen rotates, they continuously beat the drum screen, improving the efficiency of black powder separation and preventing the drum screen mesh from clogging.

[0066] like Figure 3 As shown, the hot blast stove 2-2 is a vertical hot blast stove, including a pyrolysis oil and gas inlet 221, a crude syngas inlet 222, an independent burner 223, a primary air inlet 224, a circulating air inlet 225, and a high-temperature flue gas outlet 226.

[0067] The pyrolysis oil and gas inlet 221 and the crude syngas inlet 222 are respectively connected to the pyrolysis oil and gas outlet 213a of the kiln tail of the carbonization system and the crude syngas outlet 512 of the gasification and melting system.

[0068] The primary air inlet 224 and the circulating air inlet 225 are connected to the heat exchanged air outlet 234 of the flue gas heat exchange device.

[0069] The hot air furnace is vertically distributed and is divided into an upper combustion chamber and a lower heat exchange chamber in the vertical direction.

[0070] The connection between the combustion chamber and the heat exchange chamber is designed with a narrow opening, and staggered baffles 227 are provided in the combustion chamber, which helps to improve the airflow turbulence in the combustion chamber, improve combustion efficiency, and reduce the generation of nitrogen oxides.

[0071] The pyrolysis oil and gas inlet 221 and the crude syngas inlet 222 are both located at the top of the hot blast stove. After they merge at the inlet, they extend a section of pipeline to enter the hot blast stove together, which helps to improve the uniformity of the composition of the gas entering the stove.

[0072] The pyrolysis oil and gas pipeline is arranged at an angle above the pyrolysis oil and gas inlet of the hot blast furnace, with an angle greater than 45° to the horizontal to prevent the easily condensable tar in the pyrolysis oil and gas pipeline from condensing and blocking the pipeline at the horizontal bend.

[0073] There are four or more independent burners 223, which are symmetrically distributed around the hot blast stove and are installed at the same height as the outlet of the pyrolysis oil and gas and crude syngas extension pipeline, so as to ensure that the gas can be ignited by open flame after entering the furnace.

[0074] The primary air inlet 224 is distributed around the pyrolysis oil and gas inlet and the crude syngas inlet, which is conducive to the full contact between air and fuel gas.

[0075] The circulating air inlet 225 is located below the constricted opening at the bottom of the pyrolysis chamber of the hot blast stove. The circulating air mixes with the high-temperature flue gas generated by combustion to obtain the high-temperature flue gas temperature required by the pyrolysis furnace annular system.

[0076] The flue gas heat exchanger 2-3 includes a medium-temperature flue gas inlet 231, a cold flue gas outlet 232, a cold air inlet 233, and a heat-exchanged air outlet 234.

[0077] The intermediate temperature flue gas inlet 231 is connected to the intermediate temperature flue gas outlet 212e.

[0078] After being crushed, waste lithium batteries are sent to a pyrolysis furnace through a sealed silo for anaerobic carbonization. This process removes residual moisture, electrolyte, separator, binder, and other organic matter from the surface of the raw materials, yielding waste battery positive and negative electrode black powder and auxiliary materials such as iron, copper, and aluminum. At the same time, pyrolysis oil and gas generated from the decomposition of organic matter are also obtained.

[0079] The carbonization system uses indirect heating with high-temperature flue gas to maintain an oxygen-free environment inside the furnace, preventing metal oxidation or volatilization and facilitating subsequent wet recovery of the metal.

[0080] The inlet and outlet temperatures of the high-temperature flue gas in the annular system are 700℃ and 550℃, respectively; the carbonization temperature inside the furnace cavity is 500℃; and the carbonization time is 90 min.

[0081] The black powder from the positive and negative electrodes of waste batteries is separated from iron, copper, aluminum, etc. by a drum screen to obtain battery black powder and associated metal materials. The associated metal materials are then recycled after being washed, magnetically separated, and vortex separated. The washing wastewater is filtered and reused, and the resulting filter residue is sent to the subsequent forming system for further processing.

[0082] The pyrolysis oil and gas are directly fed into the hot blast stove and burned together with the crude syngas produced in the gasification and melting furnace (combustion temperature ≥1100℃) to produce high-temperature flue gas, which serves as the heat source for the pyrolysis furnace; insufficient heat source is supplemented by natural gas.

[0083] The medium-temperature flue gas exiting the pyrolysis furnace ring system exchanges heat with the cold air through the flue gas heat exchanger. After heat exchange, the air enters the hot blast furnace as primary air and circulating air to realize waste heat utilization. After heat exchange, the low-temperature flue gas enters the drying device of the molding system, and after drying the molded blocks, it enters the flue gas purification system.

[0084] Step 3: Control of lithium extraction using battery black powder.

[0085] A lithium extraction system controlled by black powder is used.

[0086] The black powder control lithium extraction system 3 includes a black powder feeder, a dosing device, a reaction tank, a solid-liquid separation device, a lithium precipitation filtration device, and an auxiliary control system connected in sequence.

[0087] The black powder feeder is connected to the battery black powder outlet of the drum screen 2-4 of the solid slag sorting system of the waste lithium battery carbonization system.

[0088] The lithium precipitation filtration device includes a lithium precipitation tank, a sodium carbonate dosing device, and a lithium carbonate filtration device.

[0089] The black powder from the positive and negative electrodes of the battery obtained by the carbonization system is leached under precise control to maximize the leaching rate of lithium while inhibiting the dissolution of other metals such as nickel and cobalt, resulting in a lithium solution and residue. The lithium solution is further precipitated with sodium carbonate and impurities removed before being utilized as a resource.

[0090] The battery black powder is ground before controlled leaching to a particle size of <100um to improve lithium leaching efficiency.

[0091] The leaching agent is oxalic acid; the concentration of the leaching agent is 0.5 mol / L.

[0092] The pH value of the leaching agent is 1.5; the mass ratio of leaching agent to black powder is 10 mL / g.

[0093] The immersion temperature was 30℃; the immersion time was 3 hours.

[0094] The pH of the leached lithium solution was adjusted to 10 with sodium carbonate to obtain lithium carbonate precipitate, which was then filtered and utilized as a resource.

[0095] Step 4: Wet molding with black powder.

[0096] A black powder wet molding system 4 is adopted.

[0097] The black powder wet molding system 4 includes a material mixer, molding equipment, drying chamber and storage chamber connected in sequence.

[0098] The material mixer is a twin-shaft agitator used to uniformly mix black powder and auxiliary additives.

[0099] The material mixer is connected to the solid slag outlet of the solid-liquid separation device of the black powder control lithium extraction system 3 and the feeding device of auxiliary additives (binder, coal powder / carbon powder, quicklime, water, etc.) via a conveying device.

[0100] The drying chamber is sealed and has an air inlet and an air outlet; the air inlet is connected to the cold flue gas outlet 232 of the flue gas heat exchanger 2-3, and the air outlet of the drying chamber is connected to the exhaust gas purification system.

[0101] The exhaust gas purification system includes a lime slurry spraying device, an activated carbon injection device, a cyclone dust collector, a bag filter, an activated carbon filter, and a chimney connected in sequence; the fly ash and solid slag generated by the purification system are sent to the gasification and melting system for treatment.

[0102] The slag obtained after wet lithium extraction is mixed with a certain amount of coal powder or carbon powder, and a certain amount of binder and water are added for wet molding to obtain black powder blocks.

[0103] The amount of pulverized coal or carbon powder added is 4% of the mass of the dry slag;

[0104] The binder is an organic-inorganic composite binder, and its addition amount is 3% of the total mass of the dry powder;

[0105] The molding method is wet molding, with a moisture content of 20%.

[0106] The black powder block has a diameter of 30mm and a length of 6cm;

[0107] After the black powder blocks are formed, they are placed in a closed drying chamber and dried by forced ventilation using the flue gas from the ring system outlet of the carbonization furnace until the moisture content is ≤10%.

[0108] Step 5: The formed block is vaporized and melted.

[0109] A shaped block gasification and melting system 5 is adopted.

[0110] The key equipment in the gasification melting system 5 is the gasification melting furnace.

[0111] like Figure 4 As shown, the gasification and melting furnace is divided into a gasification section 5-1 and a melting section 5-2.

[0112] The upper end of the gasification section is equipped with a gasification feed inlet 511 and a crude syngas outlet 512.

[0113] An oxygen-enriched air inlet 513 is provided at the lower end of the gasification section where it connects with the melting section 5-2.

[0114] The melting section 5-2 is equipped with a plasma torch 514, a slag outlet 515, and a metal alloy outlet 516;

[0115] The melting section 5-2 of the gasification melting furnace is inverted trapezoidal in shape, which reduces the melting space, increases the thickness of the refractory material, improves the heat accumulation capacity of the melting section, and improves the system's heat utilization rate.

[0116] The crude syngas outlet 512 is equipped with a gas sampling and analysis device to monitor the CO2 and CO content in the crude syngas in real time, thereby controlling the intake of oxygen-enriched air and ensuring a strong reducing atmosphere in the gasification and melting furnace.

[0117] The gasification inlet 511 is connected to the drying chamber of the black powder wet forming system.

[0118] The slag outlet 515 and the metal alloy outlet 516 are respectively connected to their corresponding slag collection containers.

[0119] The slag outlet 515 is located below the plasma torch 514 and above the metal alloy outlet 516.

[0120] The slag and alloy are discharged intermittently after being separated into layers based on their different densities.

[0121] After drying, the black powder forming blocks and other process wastes generated by the system (crushed chips, carbonized ash, activated carbon, deacidifying agents, etc.) are fed into the gasification and melting furnace through a sealed feeding device to obtain crude syngas, molten solid slag, and metal alloys such as nickel, cobalt, and manganese.

[0122] The gasification-melting furnace is divided into a gasification section and a melting section from top to bottom. The temperature of the gasification section is 600℃; the temperature of the melting section is 1100℃, and the processing time is 120min; the oxygen content in the oxygen-enriched air is 30%; and the outlet temperature of the crude syngas is 600℃.

[0123] The amount of oxygen-enriched air added is determined based on the C content in the raw materials, so that the molar ratio of CO2 to CO in the obtained crude syngas is controlled between 0.2 and 0.8, ensuring a strong reducing atmosphere inside the furnace.

[0124] The crude syngas mainly consists of CO, H2, CO2, CH4, and small amounts of pollutants such as HF, P2O5, dust, or volatile metals. It is directly fed into a hot blast furnace for combustion, producing high-temperature flue gas.

[0125] After the slag and metal alloys are separated at the bottom of the furnace, they are collected and cooled separately through slag collection containers and metal collection containers for later use. The slag does not have leaching toxicity and can be safely used in building materials; the alloys are crushed and sorted for further resource utilization, with high recovery rate and purity. Example

[0126] The only difference between Example 2 and Example 1 in the disposal of used lithium batteries is that:

[0127] The waste batteries were crushed to 50mm; the solution used for salt discharge was 10% sodium sulfate salt water, and the discharge time was 96 hours; the inlet and outlet temperatures of the annular high-temperature flue gas were 850℃ and 650℃, respectively; the carbonization temperature inside the furnace cavity was 600℃; the carbonization time was 30 minutes; the leaching agent was citric acid; the concentration of the leaching agent was 2 mol / L; the pH value of the leaching agent was 3.0; the mass ratio of leaching agent to black powder was 20:1. mL / g; leaching temperature: 70℃; leaching time: 3h; pH of the leached lithium solution was adjusted to 11 with sodium carbonate; the amount of coal powder or carbon powder added was 8% of the dry slag mass; the binder was an organic-inorganic composite binder, and the amount added was 10% of the total dry powder mass; the molding method was wet molding, with a moisture content of 35%; the diameter of the black powder block was 50mm and the length was 10cm; the gasification and melting furnace was divided into a gasification section and a melting section from top to bottom, with the temperature of the gasification section being 1100℃; the temperature of the melting section being 1700℃ and the processing time being 60min; the oxygen content in the oxygen-enriched air was 40%; the outlet temperature of the crude syngas was 800℃.

[0128] Ternary lithium battery recycling and disposal: Waste batteries are first pre-treated in an 8% sodium sulfate solution for 72 hours, then drained and crushed to ≤50mm.

[0129] After crushing, the battery fragments are pushed into the rotary carbonizer by the sealed screw feeder (the inlet and outlet temperatures of the carbonizer ring system are 750±10℃ and 580±10℃, respectively). Guided by the spiral baffle, they are transported from the kiln head to the kiln tail as the kiln body rotates, and pyrolysis is gradually achieved in the process. The pyrolysis oil and gas generated by pyrolysis are extracted from the kiln tail by the induced draft fan and directly sent to the hot blast furnace for combustion, generating high-temperature flue gas, which is used as a heat source to enter the pyrolysis ring system. The solid slag generated by pyrolysis is first separated by a drum screen to obtain battery black powder (accounting for 51.7% of the raw materials) and auxiliary metal materials (iron, copper, and aluminum). The auxiliary metal materials are then separated by magnetic separation and vortex separation to obtain iron (9.8%) and a copper-aluminum mixture (22.1%).

[0130] The battery black powder produced by pyrolysis is further ground and sent to a controlled lithium extraction reaction tank. After stirring and soaking in 0.5 mol / L oxalic acid solution (30℃, pH=2.8) for 2 hours, solid-liquid separation is performed to obtain lithium solution (cobalt solubility 0.78%) and remaining black residue. The pH of the lithium solution is adjusted to 11 using sodium carbonate and then filtered to obtain high-purity lithium carbonate (extraction rate 87.5%).

[0131] After controlling lithium extraction, 4wt% coal powder and 3wt% binder are added to the remaining black slag, and the water content is adjusted to 30%. The mixture is then evenly mixed by a material mixing device and sent to a wet molding machine for molding. The molded black powder blocks (φ30*60mm) are placed in a sealed drying chamber for drying.

[0132] After drying, the black powder blocks (8% moisture content) are fed into the gasification and melting furnace via a sealed feeder. At the same time, other hazardous solid waste generated by the system is also sealed and fed into the gasification and melting furnace, dispersed in the black powder blocks for joint disposal. The black powder blocks form a material layer in the furnace and slowly move downwards, gradually gasifying (800-1100℃) and melting (1100-1500℃). The organic matter in the blocks is decomposed by gasification to form high-value-added crude syngas. The remaining inorganic components, dioxins, heavy metals, etc., eventually form liquid slag under a high-temperature reducing atmosphere.

[0133] The crude syngas (800℃) generated in the gasification melting furnace escapes from the gasification melting furnace under the action of the blower and enters the hot blast stove for complete combustion (combustion temperature 1200℃) to produce high-temperature flue gas, which serves as the heat source for the pyrolysis machine's annular system. The pyrolysis flue gas exchanges heat with cold air through a flue gas heat exchanger and serves as the primary air and circulating air for the hot blast stove. After heat exchange, the flue gas enters the wet-process molded block sealed drying chamber to dry the molded blocks before being sent to the tail gas purification system for treatment and emission in compliance with standards.

[0134] The liquid slag and metal slag discharged from the bottom of the gasification melting furnace are further separated and utilized after cooling.

[0135] Lithium iron phosphate battery recycling and disposal: Waste batteries are first pre-treated in an 8% sodium sulfate solution for 72 hours, then drained and crushed to ≤50mm.

[0136] After crushing, the battery fragments are pushed into the rotary carbonizer by the sealed screw feeder (the inlet and outlet temperatures of the carbonizer ring system are 750±10℃ and 580±10℃, respectively). Guided by the screw baffle, they are transported from the kiln head to the kiln tail as the kiln body rotates, and pyrolysis is gradually achieved in the process. The pyrolysis oil and gas generated by pyrolysis are extracted from the kiln tail by the induced draft fan and directly sent to the hot blast furnace for combustion, generating high-temperature flue gas, which is used as a heat source to enter the pyrolysis ring system. The solid slag generated by pyrolysis is first separated by a drum screen to obtain battery black powder (accounting for 30.5% of the raw materials) and auxiliary metal materials (iron, copper, and aluminum). The auxiliary metal materials are then separated by magnetic separation and vortex separation to obtain iron (28.4%) and a copper-aluminum mixture (16.9%).

[0137] The battery black powder produced by pyrolysis is further ground and sent to a controlled lithium extraction reaction tank. After stirring and soaking in 1.0 mol / L oxalic acid solution (40℃, pH=2.8) for 2 hours, solid-liquid separation is performed to obtain lithium solution (iron dissolution rate 2.7%) and remaining black residue. The pH of the lithium solution is adjusted to 11 using sodium carbonate and then filtered to obtain high-purity lithium carbonate (extraction rate 94.2%).

[0138] After controlling lithium extraction, 6wt% coal powder and 3wt% binder are added to the remaining black slag, and the water content is adjusted to 35%. The mixture is then evenly mixed by a material mixing device and sent to a wet molding machine for molding. The molded black powder blocks (φ30*60mm) are placed in a sealed drying chamber for drying.

[0139] After drying, the black powder blocks (8% moisture content) are fed into the gasification and melting furnace via a sealed feeder. At the same time, other hazardous solid waste generated by the system is also sealed and fed into the gasification and melting furnace, dispersed in the black powder blocks for joint disposal. The black powder blocks form a material layer in the furnace and slowly move downwards, gradually gasifying (800-1100℃) and melting (1100-1500℃). The organic matter in the blocks is decomposed by gasification to form high-value-added crude syngas. The remaining inorganic components, dioxins, heavy metals, etc., eventually form liquid slag under a high-temperature reducing atmosphere.

[0140] The crude syngas (800℃) generated in the gasification melting furnace escapes from the gasification melting furnace under the action of the blower and enters the hot blast stove for complete combustion (combustion temperature 1200℃) to produce high-temperature flue gas, which serves as the heat source for the pyrolysis machine's annular system. The pyrolysis flue gas exchanges heat with cold air through a flue gas heat exchanger and serves as the primary air and circulating air for the hot blast stove. After heat exchange, the flue gas enters the wet-process molded block sealed drying chamber to dry the molded blocks before being sent to the tail gas purification system for treatment and emission in compliance with standards.

[0141] The liquid slag and metal slag discharged from the bottom of the gasification melting furnace are further separated and utilized after cooling.

Claims

1. A spent lithium battery disposal system, comprising: Including the following settings in sequence: Preprocessing system (1); Carbonization system (2); Lithium extraction system for black powder control (3); Black powder wet molding system (4); Molded block gasification and melting system (5); The carbonization system includes: a rotary pyrolysis machine (2-1), a hot blast furnace (2-2), a flue gas heat exchanger (2-3), and a drum screen (2-4), a water washing device (2-5), a magnetic separation device (2-6), and a vortex separation device (2-7) for the carbonization slag sorting system. The rotary pyrolysis machine (2-1) includes a kiln head (211), a kiln body (212), and a kiln tail (213). The kiln head (211) is provided with a kiln head feed inlet (211a), which is connected to the pretreatment system (1); The kiln body (212) includes a high-temperature flue gas annular channel (212a), a pyrolysis chamber (212b), a spiral baffle (212c) inside the pyrolysis chamber, and a high-temperature flue gas inlet (212d) and a medium-temperature flue gas outlet (212e) connected to the high-temperature flue gas annular channel; the high-temperature flue gas inlet (212d) is connected to the outlet of the hot blast stove (2-2), and the medium-temperature flue gas outlet (212e) is connected to the flue gas heat exchanger (2-3); The kiln tail (213) is provided with a pyrolysis oil and gas outlet (213a) and a pyrolysis solid slag outlet (213b); the pyrolysis oil and gas outlet (213a) is connected to the inlet of the hot blast stove (2-2), and the pyrolysis solid slag outlet (213b) is connected in sequence to a drum screen (2-4), a water washing device (2-5), a magnetic separation device (2-6), and a vortex separation device (2-7).

2. The waste old lithium battery disposal system according to claim 1, wherein, The pretreatment system includes a brine discharge device, a coarse crushing device, and a fine crushing device arranged in sequence.

3. The waste old lithium battery disposal system according to claim 1, wherein, The hot blast stove (2-2) includes a pyrolysis oil and gas inlet (221), a crude syngas inlet (222), an independent burner (223), a primary air inlet (224), a circulating air inlet (225), and a high-temperature flue gas outlet (226). The hot air furnace (2-2) is vertically divided into an upper combustion chamber and a lower heat exchange chamber; The connection between the combustion chamber and the heat exchange chamber is narrowed, and staggered baffles (227) are provided inside the combustion chamber. The pyrolysis oil and gas inlet (221) and the crude syngas inlet (222) are respectively connected to the pyrolysis oil and gas outlet (213a) and the crude syngas outlet of the shaped block gasification and melting system (5). The pyrolysis oil and gas inlet (221) and the crude syngas inlet (222) merge and enter the hot blast furnace together. The independent burners (223) are distributed around the perimeter of the hot blast stove; The primary air inlet (224) is distributed around the pyrolysis oil and gas inlet (221) and the crude syngas inlet (222); The circulating air inlet (225) is located at the bottom of the combustion chamber; the high-temperature flue gas outlet (226) is connected to the high-temperature flue gas inlet (212d). The flue gas heat exchanger (2-3) includes a medium-temperature flue gas inlet (231), a cold flue gas outlet (232), a cold air inlet (233), and a heat-exchanged air outlet (234). The medium-temperature flue gas exchanges heat with the cold air and enters the hot air furnace as primary air and circulating air. The waste gas generated in the pretreatment system (1) is mixed as primary air.

4. The waste old lithium battery disposal system according to claim 1, wherein, The black powder controlled lithium extraction system (3) includes a black powder feeder, a dosing device, a reaction tank, a solid-liquid separation device, a lithium precipitation filtration device, and an auxiliary control system connected in sequence. The black powder generated by the carbonization system (2) is fed into the black powder feeder. The lithium precipitation filtration device includes a lithium precipitation tank, a sodium carbonate dosing device and a lithium carbonate filtration device.

5. The waste old lithium battery disposal system according to claim 1, wherein, The black powder wet molding system (4) includes a material mixer, molding equipment, drying chamber and storage chamber connected in sequence; the material mixer is connected to the solid slag outlet and auxiliary additive feeding device of the black powder controlled lithium extraction system (3) through a conveying device. The drying chamber is provided with an air inlet and an air outlet. The air inlet is connected to the cold flue gas produced in the carbonization system (2), and the air outlet is connected to the exhaust gas purification system. The exhaust gas purification system includes a lime slurry spraying device, an activated carbon injection device, a cyclone dust collector, a bag filter, an activated carbon filter, and a chimney connected in sequence; the fly ash and solid slag generated by the purification system are sent to the shaped block gasification and melting system (5).

6. The waste old lithium battery disposal system according to claim 1, wherein, The shaped block gasification and melting system (5) includes a gasification and melting furnace; The gasification and melting furnace is divided into a gasification section (5-1) and a melting section (5-2). The upper end of the gasification section (5-1) is provided with a gasification feed inlet (511) and a crude syngas outlet (512). An oxygen-enriched air inlet (513) is provided at the lower end of the gasification section where it connects with the melting section (5-2). The melting section (5-2) is equipped with a plasma torch (514), a slag outlet (515), and a metal alloy outlet (516). The molten section (5-2) is inverted trapezoidal in shape; The gasification feed inlet (511) is connected to the black powder wet forming system (4); the crude syngas outlet (512) is equipped with a gas sampling and analysis device; the slag outlet (515) and the metal alloy outlet (516) are respectively connected to their corresponding slag collection containers.

7. The waste old lithium battery disposal system according to claim 6, characterized in that, The slag outlet (515) is located below the plasma torch (514) and above the metal alloy outlet (516); the slag and alloy are intermittently discharged after being layered based on different densities.

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