A method and system for treating waste lithium-ion battery black powder by fire and wet processes in combination

Abstract

The present application relates to the field of lithium ion battery recycling, and particularly relates to a kind of waste lithium ion battery black powder fire method wet method combined processing method and system.Recovery method includes: the carbon black removal powder obtained after the black powder is floated is dried, broken to obtain powdered material;Graphite after flotation is used to prepare CO;The powdered material is mixed with preheated gas and sprayed into the hot hearth, reaction is carried out, and powdered reduction product is obtained;The powdered reduction product is slightly cooled and sprayed into leaching device, dissolved leaching is carried out using sulfuric acid spray, and leaching solution containing nickel, cobalt, manganese and lithium and filter residue are obtained.The problems of long leaching time, use of large amounts of acid and reducing agent, and large amounts of wastewater requiring treatment during the leaching process of waste lithium ion battery black powder are solved.The present application also provides a kind of waste lithium ion battery black powder efficient fire method wet method combined processing system.

Description

Technical Field

[0001] This invention relates to the field of resource recycling, and in particular to a method and system for the efficient processing of waste lithium-ion battery black powder raw materials. Background Technology

[0002] With the rapid development of the new energy vehicle sector, the number of its core component, lithium-ion power battery modules, has also increased dramatically. Given that the typical lifespan of lithium-ion batteries is 5-8 years, a large number of used lithium-ion batteries from the first batch of new energy vehicles urgently need to be properly disposed of. How to scientifically recycle and regenerate them is a key issue that requires attention.

[0003] The current conventional process for treating spent lithium-ion battery black powder involves dissolving the black powder using a sulfuric acid and hydrogen peroxide system, then using a reducing agent to reduce the high-valence metal ions, thereby leaching out the metal elements from the black powder for subsequent processing. However, this process has drawbacks, including a long leaching time, the need for large amounts of acid and reducing agents, and the difficulty in treating the wastewater.

[0004] Chinese patent CN112207119B discloses a method for treating battery black powder. First, the black powder is slurried using diethanol and heated to react. Then, acid and oxidant are used for leaching and filtration separation. Finally, the filtrate is extracted to achieve the purpose of recovery. Summary of the Invention

[0005] To address the problems of long leaching times and the use of large amounts of acid and reducing agents in conventional wet dissolution and leaching processes for black powder, one of the objectives of this invention is to provide a black powder treatment system that combines wet and pyrometallurgical methods. This system can pre-treat black powder, enabling it to achieve rapid and efficient leaching while reducing the amount of acid and reducing agents used.

[0006] The second objective of this invention is to provide a method for recycling and processing waste square lithium-ion batteries.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] In a first aspect, the present invention provides a method for the efficient combined pyrometallurgical and hydrometallurgical treatment of waste lithium-ion battery black powder, comprising:

[0009] Step S11: The black powder is subjected to flotation to obtain decarbonized black powder and waste graphite;

[0010] Step S12: Waste graphite is sintered to obtain reducing gas CO and lithium-containing sintering slag;

[0011] Step S13: The carbon black powder mixed with CO is injected into the incandescent reduction chamber to react and obtain the powdered reduction product.

[0012] Step S14: After the powdered reduction product is slightly cooled, it is sprayed into the leaching tower and dissolved and filtered using sulfuric acid solution to obtain a leaching solution containing nickel, cobalt, manganese and lithium and carbon filter residue.

[0013] In step S15, lithium is extracted by acid leaching of the lithium-containing sintered slag in step 12.

[0014] In some embodiments, the decarbon black powder is dried and crushed to obtain a powdered material; wherein the powdered material has a particle size of less than 0.3 mm and a water content of less than 0.5%;

[0015] In some embodiments, the preheating gas in the powder nozzle is a mixture of carbon monoxide, carbon dioxide, and an inert gas; the temperature of the preheating gas is 250-300°C; and the inert gas can be argon, nitrogen, etc.

[0016] In some embodiments, the powdered reduction product is mainly composed of metals such as nickel, cobalt, manganese, copper, and iron, or their low-valence oxides.

[0017] In some embodiments, the powdered reduction product is cooled to 150-200°C.

[0018] On the other hand, this invention provides a high-efficiency pyrometallurgical and hydrometallurgical combined treatment system for waste lithium-ion battery black powder, comprising: a flotation unit, a drying unit, a crushing unit, a reduction unit, an atmosphere separation and purification unit, and a leaching unit. The flotation unit is used to separate carbon, obtaining decarbonized black powder and waste graphite; the drying unit is used to dry the products obtained from flotation; the crushing unit is used to control the particle size of the decarbonized black powder; the reduction unit is used to reduce high-valence nickel, cobalt, and manganese metal oxides to metals or low-valence oxides; the atmosphere separation and purification unit is used to treat the reaction gas; and the leaching unit is used to dissolve and leach the low-valence oxides or metals obtained from reduction.

[0019] In some embodiments, the flotation apparatus includes a flotation machine;

[0020] In some embodiments, the drying apparatus includes conventional drying equipment, such as a drum dryer;

[0021] In some embodiments, the crushing device includes a ball mill;

[0022] In some embodiments, the reduction apparatus is used to reduce high-valence, difficult-to-leach oxides in black powder to low-valence oxides or metals, mainly comprising:

[0023] Reducing gas preparation chamber, used to prepare CO;

[0024] Preheating chamber, used for mixing and preheating gases;

[0025] Raw material silo, used to store decarbon black powder;

[0026] The reactant injection device is used to mix the reactants with preheated gas and rapidly inject them into the pipe-shaped reaction chamber, so that the powdered reactants are dispersed and advanced.

[0027] The powder reaction furnace is used for reduction reactions;

[0028] Cooling device, used to cool the powdered reduction product to 150-200℃;

[0029] The primary, secondary, and tertiary silos are used to transport powder materials to the leaching unit without introducing external atmospheres.

[0030] In some embodiments, the atmosphere separation and purification device is used to separate and purify the reaction gas so that it can be recycled.

[0031] In some embodiments, the leaching apparatus is used to leach powdered reduction products to obtain a leachate containing valence metal elements, mainly comprising:

[0032] Powder nozzles are used to rapidly spray hot powder from the hopper into the leaching device, so that the powder is in a dispersed state.

[0033] An acid leaching dissolution device is used to spray acid solution into the internal space of the device to quickly complete the leaching of powdered reduction products at a high temperature.

[0034] A filtration device is used to separate the powdered reduction product from the sprayed leachate to obtain leachate and carbon residue.

[0035] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0036] (1) The method and system proposed in this invention can solve the problem that black powder needs to consume a large amount of inorganic acid and reducing agent and has a long leaching time during the leaching process.

[0037] (2) This invention utilizes the large active surface properties of black powder by flotation and refining the decarbonized black powder particles in a high-temperature furnace under an inert atmosphere. The high-valence metal oxides in the black powder, which are difficult to leach directly using conventional acid leaching, are rapidly reduced to low-valence oxides or their metals using the reducing agent CO. Subsequently, the cooled, low-temperature powdered reduction product is sprayed into a leaching device. The residual heat of the powdered reduction product is used to complete the leaching of metal elements in a very short time by spraying sulfuric acid. Finally, the undissolved impurities are filtered out, yielding a leachate containing nickel, cobalt, manganese, lithium, copper, and aluminum. Simultaneously, the waste graphite in the black powder is used to prepare the reducing gas CO, thus realizing its value utilization. Attached Figure Description

[0038] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0039] Figure 1 A schematic diagram of a combined pyrometallurgical and hydrometallurgical process for the treatment of waste lithium-ion battery black powder is shown.

[0040] Figure 2 A schematic diagram of a combined pyrometallurgical and hydrometallurgical treatment system for waste lithium-ion battery black powder is shown.

[0041] Figure 3 A schematic diagram of the reduction device is shown, in which 1 is the reducing gas preparation chamber, 2 is the preheating chamber, 3 is the raw material chamber, 4 is the reactant injection device, 5 is the powder reaction furnace, 6 is the cooling device, 7 is the atmosphere separation and purification device, 8 is the silo, 11 is the air inlet, 12 is the CO2 inlet, 13 is the CO collector, 21 is the Ar inlet, 22 is the gas preheating device, 51 is the heating and insulation layer, 52 is the reaction furnace wall, 53 is the reaction furnace, 54 is the air blowing hole, 61 is the cooling and insulation layer, 62 is the cooling layer, 63 is the vibrating screen, 81 is the primary silo, 82 is the sealed valve, and 83 is the secondary silo.

[0042] Figure 4 A schematic diagram of the leaching device is shown, in which 9 is the hopper, 10 is the powder nozzle, 11 is the acid leaching dissolution device, 12 is the filter device, 13 is the leaching liquid outlet, 111 is the acid inlet, and 112 is the spray head. Detailed Implementation

[0043] To facilitate understanding of the present invention, the present invention will be described more fully and in detail below with reference to the accompanying drawings and preferred embodiments, but the scope of protection of the present invention is not limited to the following specific embodiments.

[0044] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of the invention.

[0045] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.

[0046] The present invention will be further described in detail below with reference to specific embodiments.

[0047] Example 1

[0048] Step 1: The waste lithium-ion battery black powder is floated to obtain waste graphite 1 and decarbonized black powder 2; the decarbonized black powder is dried and crushed to obtain powdered raw material 3, which is then fed into the silo; the powdered raw material 3 has a particle size of less than 1 mm and a moisture content of less than 0.5%; the waste graphite 1 is fed into the reducing gas preparation chamber for the preparation of CO.

[0049] Step two: The powdered raw material 3 in the silo is fed into the material injection device; in the preheating chamber, after the preheating gas mixture (CO, CO2 and argon are mixed in a volume ratio of 3:1:6) is preheated to the specified temperature (250-300℃), it enters the material injection device, and the powdered raw material 3 is horizontally injected into the furnace. The material is in a suspended and dispersed state in the furnace. The reducing agent and oxide react rapidly in the furnace to obtain the powdered reduction product 4; the reaction furnace is a cylindrical kiln body with oblique blowing holes at the bottom to blow a high-temperature reducing gas mixture into the furnace, providing the reducing atmosphere and temperature required for the reaction, and using airflow to ensure that the particles are suspended and dispersed in the furnace; the furnace temperature during the reduction reaction is maintained at 550-650 degrees Celsius;

[0050] Step 3: The powdered reduction product 4 passes through the cooling device with the airflow. A separation screen is set at the end of the cooling device to achieve gas-solid separation. The temperature of the powder blown into the leaching device is 150-200℃. The cooling device also has an inclined air blowing hole at the bottom of the device to introduce lower temperature gas into the cooling device to work with the cooling device to quickly cool the powder. The cooling device is equipped with a waste heat utilization device, which can be used to preheat the gas. The powdered reduction product 4 is collected in the primary silo. After the powder in the primary silo reaches two-thirds full, the secondary silo is opened. When the powder in the primary silo drops to one-quarter full, the primary and secondary silo interfaces are closed, and the tertiary silo is opened.

[0051] Step four: The powder is fed into the powder nozzle from the three-stage silo and blown into the leaching device by 150°C hot air for sulfuric acid spraying. The residual heat of the powdered reduction product and the large reaction contact area of ​​the powdered material are used to achieve rapid dissolution and leaching. After filtering out the undissolved impurities, the leachate is obtained. The sulfuric acid concentration is 2-4 mol / L.

[0052] Step five: The gas after separating the powdered reduction product enters a purification device to recover and purify CO2 and inert gas (Ar) for recycling. The recovery and purification of CO2 and inert gas (Ar) is accomplished by utilizing the different boiling points of the gases.

[0053] The above are merely preferred embodiments of the present invention and are not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of the present invention.

Claims

1. A method for combined pyrometallurgical and hydrometallurgical treatment of waste lithium-ion battery black powder, characterized in that, Includes the following steps: (1) Waste lithium-ion battery black powder is floated to obtain waste graphite and decarbonized black powder; the decarbonized black powder is dried and crushed to obtain powdered raw material and fed into the silo; the waste graphite is fed into the reducing gas preparation chamber for CO preparation; (2) The powdered raw material in the silo is injected into the powder reaction furnace by preheated gas to obtain powdered reduction product. The powdered material is in a suspended and dispersed state in the powder reaction furnace. The temperature of the preheated gas is 250-350℃, and the temperature at which the reduction reaction occurs in the powder reaction furnace is 550-650℃. (3) The powdered reduction product is cooled and collected by airflow into a cooling device; the gas after reaction is recycled into an atmosphere separation and purification device. (4) The powdered reduction product is transferred through the first, second and third stage silos and enters the leaching device through the powder nozzle. It is sprayed with acid solution for rapid leaching and filtered to obtain a leaching solution of valuable metal elements in black powder. The temperature of the powder blown into the leaching device is 150-200℃. The preheating gas in step (2) is a mixture of CO, CO2 and Ar; The apparatus used for the above-mentioned combined pyrometallurgical and hydrometallurgical treatment method for waste lithium-ion battery black powder includes a flotation device, a drying device, a crushing device, a reduction device, an atmosphere separation and purification device, and a leaching device. The reduction device includes a reducing gas preparation chamber for preparing CO; and a preheating chamber for mixing and preheating gases. The raw material silo stores decarbonized black powder; the reactant injection device mixes the reactants with preheated gas and rapidly injects the mixture into the pipe-shaped reaction chamber, dispersing the powdered reactants forward; the powder reaction furnace is used for the reduction reaction; the reaction furnace is a cylindrical kiln with inclined air holes at the bottom to blow high-temperature reducing gas, providing temperature, atmosphere, and propulsion for the powder; the cooling device cools the powdered reduction product to 150-200℃; the cooling device has inclined air holes at the bottom to blow low-temperature inert gas for cooling and providing propulsion; the first, second, and third stage silos located at the bottom of the cooling device collect the cooled powdered reduction product and send the material to the leaching device without introducing external atmosphere into the reduction device; The leaching device includes a powder nozzle at the top for uniformly spraying powder into the device and dispersing the powder in a spatial state; an acid spraying and dissolving device around the inner wall of the device for spraying acid solution into the space inside the device to quickly complete the leaching of the powdered reduction product at a high temperature; and a filter device in the lower half of the device for separating the powdered reduction product from the sprayed leachate to obtain leachate and carbon residue.

2. The combined pyrometallurgical and hydrometallurgical treatment method for waste lithium-ion battery black powder as described in claim 1, characterized in that, The flotation device is used to float waste lithium-ion battery black powder to obtain decarbonized black powder and waste graphite; the drying device is used to dry the decarbonized black powder; the crushing device is used to refine the particle size of the decarbonized black powder; the reduction device is used to reduce the high-valence, difficult-to-leach oxides in the black powder to low-valence oxides or metals; the atmosphere separation and purification device is used to separate and purify the gas after the reaction for recycling; the leaching device is used to leach the powdered reduction product to obtain a leachate containing valence metal elements.

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