CN-115911635-B - Low-copper aluminum fluoride-free black powder and preparation method thereof

Abstract

The invention discloses a low copper aluminum fluoride-free black powder and a preparation method thereof, waste batteries are crushed and screened to obtain a first black powder and a first oversize product, the first oversize product is pyrolyzed, a second black powder and a second oversize product are screened, the second oversize product is subjected to color selection to obtain copper foil and an aluminum-containing pole piece, the aluminum-containing pole piece reacts in ferric salt solution, aluminum foil and slurry are obtained through screening, third black powder is obtained through solid-liquid separation of the slurry, and the first, second and third black powder are roasted in air containing water vapor, so that low-copper aluminum fluoride-free black powder is obtained. The invention adopts the combined process of low-temperature pyrolysis, color separation, salt washing desorption and pyrogenic defluorination to recover the copper foil, aluminum foil and black powder with high value.

Inventors

• YU HAIJUN
• WANG TAO
• XIE YINGHAO
• LI AIXIA
• ZHANG XUEMEI
• LI CHANGDONG

Assignees

• 广东邦普循环科技有限公司
• 湖南邦普循环科技有限公司

Dates

Publication Date

20260505

Application Date

20221222

Claims (8)

1. 1. The preparation method of the low-copper aluminum fluoride-free black powder is characterized by comprising the following steps of: S1, discharging, disassembling, crushing and first screening the waste lithium ion batteries to obtain first black powder and first oversize products; s2, pyrolyzing the first oversize material at 300-400 ℃ in an inert atmosphere, sieving the pyrolyzed material for the second time to obtain second black powder and second oversize material, and performing color separation on the second oversize material to obtain copper foil and aluminum-containing pole pieces; s3, placing the aluminum-containing pole piece in a ferric salt solution for reaction, sieving the obtained reaction material for the third time to obtain aluminum foil and slurry, performing solid-liquid separation on the slurry, and drying the obtained solid to obtain third black powder; S4, blowing air into the first black powder, the second black powder and the third black powder at 500-1000 ℃ for roasting, wherein the volume content of water vapor in the air is 10% -40%, and the low-copper aluminum fluoride-free black powder is obtained, and the flow rate of the air is 8-15Nm 3 /min; the low-copper aluminum fluoride-free black powder has the water content less than or equal to 1.0wt%, the total content of nickel, cobalt and manganese metal elements more than or equal to 30.0wt%, the content of lithium elements more than or equal to 3.3wt%, the content of copper elements less than or equal to 0.8wt%, the content of aluminum less than or equal to 1.0wt%, and the content of fluorine less than or equal to 0.1wt%.
2. 2. The method according to claim 1, wherein in the step S1, the particle size of the crushed material obtained after crushing is not more than 5cm.
3. 3. The method according to claim 1, wherein in step S1, the waste lithium ion battery is at least one of a ternary lithium ion battery, a lithium cobaltate battery, a lithium manganate battery and a lithium nickelate battery.
4. 4. The method according to claim 1, wherein the mesh size of the first, second and third sieves is independently 0.2-0.3mm.
5. 5. The method of claim 1, wherein the pyrolysis time is 3-5 hours in step S2.
6. 6. The method according to claim 1, wherein in the step S3, the solid-to-liquid ratio of the aluminum-containing pole piece to the ferric salt solution is 0.5-2.0g/mL, and the concentration of iron ions in the ferric salt solution is 0.1-0.5mol/L.
7. 7. The method according to claim 1, wherein the temperature of the reaction in step S3 is 40 to 90 ℃.
8. 8. The method according to claim 1, wherein in step S3, the ferric salt solution is at least one of an iron sulfate solution, an iron nitrate solution, or an iron chloride solution.

Description

Low-copper aluminum fluoride-free black powder and preparation method thereof Technical Field The invention belongs to the technical field of lithium battery recovery, and particularly relates to low-copper aluminum fluoride-free black powder and a preparation method thereof. Background The lithium ion battery has the advantages of high voltage, small volume, large energy density, small self-discharge, high safety and the like, and is widely applied to various fields of consumer electronic products, power batteries, industrial energy storage and the like. In recent years, with the rapid increase of the production quantity and the use quantity of lithium ion batteries, the quantity of waste lithium ion batteries is also increasing. At present, the recycling of lithium ion batteries has been increasingly emphasized. The waste battery black powder is black powder of nickel, cobalt, manganese, copper, aluminum, lithium and other metals and carbon powder obtained by the steps of disassembly, crushing, screening, pyrolysis, sorting and the like of the waste lithium ion battery. Generally, the black powder adopts a wet leaching process to recover valuable metals therein. The method comprises the steps of leaching nickel, cobalt, manganese and lithium in a sulfuric acid system with a reducing agent, removing impurities from the leaching solution, extracting, back extracting and the like to obtain nickel sulfate, manganese sulfate and cobalt sulfate solutions respectively, evaporating and concentrating the final extract, and precipitating lithium carbonate by adopting a supersaturated sodium carbonate solution. However, in the preparation process of the black powder, the adopted pyrolysis pretreatment process is widely used in the existing industrial production, but has larger problems, such as ① conventional pyrolysis temperature is above 500 ℃, electrolyte and a diaphragm are combusted at the temperature, so that partial reaction in a pyrolysis furnace is extremely easy to be violent, the temperature is out of control, aluminum metal in a battery can undergo thermit reaction at the temperature above 600 ℃, the instant temperature is extremely high, the pyrolysis furnace is burnt, the larger safety risk is brought, ② at the temperature is greatly oxidized, the impurity content in the battery powder is high, and in addition, during the subsequent acid leaching, a large amount of copper-aluminum slag is generated, the consumed acid-base amount is large, the product is low, and the subsequent purification and purification bring larger pressure. The oxidation condition of copper and aluminum can be improved by adopting anaerobic pyrolysis through inert gas, but the current equipment is difficult to achieve complete sealing, copper and aluminum are still partially oxidized, and a binder PVDF, lithium hexafluorophosphate and the like in electrolyte are decomposed and remained in ③ pyrolysis process, so that the content of fluoride in black powder is higher, waste water is discharged and does not reach standards after wet treatment, calcium fluoride slag generated after calcium solidification belongs to dangerous waste, qualified treatment factories are required to specially treat the waste, lithium fluoride belongs to precipitation, part of fluorine enters into lithium extraction liquid, the subsequent lithium extraction rate is reduced, the purity of lithium carbonate is reduced, and the content of fluorine impurities is increased. Therefore, in order to avoid the trouble of downstream manufacturers for wet processing the black powder, improvement of the front-end process is needed to obtain the black powder with low copper aluminum fluorine content. Disclosure of Invention The present invention aims to solve at least one of the technical problems in the prior art described above. Therefore, the invention provides the low-copper aluminum fluoride-free black powder and the preparation method thereof, wherein the copper aluminum foil can be recovered through low-temperature pyrolysis and defluorinated to prepare the low-copper aluminum fluoride-free black powder. According to one aspect of the invention, a low-copper aluminum fluoride-free black powder is provided, wherein the water content of the low-copper aluminum fluoride-free black powder is less than or equal to 1.0wt%, the total content of nickel, cobalt and manganese metal elements is more than or equal to 30.0wt%, the content of lithium element is more than or equal to 3.3wt%, the content of copper element is less than or equal to 0.8wt%, the content of aluminum is less than or equal to 1.0wt%, and the content of fluorine is less than or equal to 0.1wt%. In some embodiments of the invention, the low copper aluminum fluorine-free black powder has a particle size of 0.25mm or less. The invention also provides a preparation method of the low-copper aluminum fluoride-free black powder, which comprises the following steps: S1, discharging, disassembling, crushing and