CN-122012947-A - Method for recycling lithium from waste lithium battery

CN122012947ACN 122012947 ACN122012947 ACN 122012947ACN-122012947-A

Abstract

The invention provides a method for recovering lithium from waste lithium batteries, which comprises the following steps of preprocessing the waste lithium batteries to obtain waste lithium battery black materials; mixing the waste lithium battery black material with a leaching agent, carrying out lithium leaching to obtain a lithium-containing leaching solution, mixing the lithium-containing leaching solution with a lithium ion adsorbent, carrying out an adsorption reaction to obtain a lithium-loaded adsorbent precipitate, and carrying out desorption treatment on the lithium-loaded adsorbent precipitate to release lithium ions to obtain a lithium-rich solution. And carrying out post-treatment on the lithium-rich solution to obtain a lithium product, wherein the lithium ion adsorbent is a metal organic coordination compound modified by photosensitive azo groups. According to the invention, the metal organic coordination compound modified by the photosensitive azo group is used as an adsorbent, lithium ions can be selectively trapped, the use of toxic organic solvents is avoided, and the lithium ions can be controllably released only by ultraviolet irradiation in the desorption process due to the light response characteristic, so that the process is simplified and green low carbon is realized while the lithium is efficiently recovered.

Inventors

XU KAIHUA
HU XIAONING
YANG JIAN
ZHANG KUN
FU MINGBO
Wan Xiaoxi
TAN FEI

Assignees

荆门动力电池再生技术有限公司
荆门市格林美新材料有限公司

Dates

Publication Date: 20260512
Application Date: 20260226

Claims (10)

1. A method for recovering lithium from waste lithium batteries, the method comprising the steps of: Pretreating the waste lithium battery to obtain a waste lithium battery black material; mixing the waste lithium battery black material with a leaching agent, and carrying out lithium leaching to obtain a lithium-containing leaching solution; mixing the lithium-containing leaching solution with a lithium ion adsorbent, and performing adsorption reaction to obtain a lithium-loaded adsorbent precipitate; desorbing the adsorbent precipitate loaded with lithium to release lithium ions to obtain a lithium-rich solution; post-processing the lithium-rich solution to obtain a lithium product; wherein the lithium ion adsorbent is a metal organic coordination compound modified by photosensitive azo groups.
2. The method of claim 1, wherein the step of preprocessing comprises: (a) Preheating the waste lithium battery, and then performing cryogenic treatment to obtain a waste lithium battery embrittlement body; (b) Crushing the waste lithium battery embrittlement body to obtain the waste lithium battery black material; preferably, the preheating temperature is 100-200 ℃ and the preheating time is 2-5 hours; preferably, the temperature of the cryogenic treatment is-50 to-100 ℃ and the time is 1-3 hours.
3. The method according to claim 2, wherein the crushing is performed under uv light irradiation and/or microwave assisted conditions; Preferably, inert gas is also introduced during the crushing process.
4. A method according to any one of claims 1 to 3, wherein the leaching agent comprises any one or a combination of at least two of oxalic acid, an amino acid, a persulfate or a fluoride; Preferably, the amino acids comprise glycine and/or glutamic acid; preferably, the persulfate comprises any one or a combination of at least two of ammonium persulfate, potassium persulfate or sodium persulfate; preferably, the fluoride comprises any one or a combination of at least two of ammonium fluoride, potassium fluoride or sodium fluoride.
5. The method according to any one of claims 1 to 4, wherein the pH of the solution system is 1.5 to 2.5 during the lithium leaching.
6. The method of any one of claims 1-5, wherein the lithium ion adsorbent comprises Li 5 L 2 , wherein L is a pentadentate pyrrole ligand containing a photosensitive azo group; preferably, the photosensitive azo group is selected from any one or a combination of at least two of an azo bipyridine group, an azo phenyl group or an azo pyrrole group; Preferably, the metal organic coordination compound is further modified with a hydrophilic group; preferably, the hydrophilic group comprises any one or a combination of at least two of hydroxyl, polyethylene glycol or sodium sulfonate groups; Preferably, the molar ratio of lithium ions to the lithium ion adsorbent in the lithium-containing leaching solution is 1 (1.5-3).
7. The method according to any one of claims 1 to 6, wherein the temperature of the adsorption reaction is 25 to 40 ℃; Preferably, the adsorption reaction time is 1-3 hours.
8. The method according to any one of claims 1 to 7, wherein crown ether extractant is also added during the mixing of the lithium-containing leach solution and the lithium ion adsorbent; Preferably, the crown ether extractant comprises any one or a combination of at least two of 12-crown-4, 15-crown-5 or benzo-15-crown-5; preferably, the molar ratio of the crown ether extractant to lithium ions in the lithium-containing leachate is (0.2-2): 1.
9. The method according to any one of claims 1-8, wherein the method of desorption treatment comprises: The lithium-loaded adsorbent precipitate was dispersed in an aqueous medium, followed by ultraviolet irradiation.
10. The method according to any one of claims 1-9, characterized in that the method comprises the steps of: (1) Providing a waste lithium battery; Preheating the waste lithium battery for 2-5 hours at 100-200 ℃, immediately transferring to-50 to-100 ℃ for 1-3 hours, and obtaining a waste lithium battery embrittlement body; placing the waste lithium battery embrittlement body into a crusher for crushing to obtain waste lithium battery black materials with the particle size D50 of 0.1-0.5 mm; Wherein ultraviolet light irradiation and microwave assistance are used in the crushing process, and inert gas is also introduced in the crushing process; (2) Placing the waste lithium battery black material into a leaching agent, adjusting the pH value of a solution system to 1.5-2.5, and controlling the temperature to 60-90 ℃ to leach lithium in the waste lithium battery black material to obtain a lithium-containing leaching solution; wherein the leaching agent comprises any one or a combination of at least two of oxalic acid, amino acid, persulfate or fluoride; (3) Adding a lithium ion adsorbent into the lithium-containing leaching solution, mixing, controlling the temperature to be 25-40 ℃, and carrying out lithium adsorption reaction for 1-3 hours to obtain a lithium-loaded adsorbent precipitate; The lithium ion adsorbent comprises a metal organic coordination compound modified by a photosensitive azo group and a hydrophilic group, wherein the photosensitive azo group is selected from any one or a combination of at least two of an azo bipyridine group, an azo phenyl group and an azo pyrrole group, the hydrophilic group comprises any one or a combination of at least two of a hydroxyl group, a polyethylene glycol group and a sodium sulfonate group, and the molar ratio of lithium ions in the lithium-containing leaching solution to the lithium ion adsorbent is 1 (1.5-3); (4) Dissolving the lithium-loaded adsorbent precipitate in water to form a dispersion; ultraviolet light with the wavelength of 300-400 nm is adopted to irradiate the dispersion liquid for 2-6 hours, so that lithium ions are released from the lithium ion adsorbent, and a lithium-rich solution is obtained; (5) Adding a precipitant or introducing carbon dioxide gas into the lithium-rich solution to generate lithium carbonate precipitate, and performing solid-liquid separation, washing and drying to obtain a battery-grade lithium carbonate product.

Description

Method for recycling lithium from waste lithium battery Technical Field The invention belongs to the technical field of waste lithium batteries, and particularly relates to a method for recycling lithium from waste lithium batteries. Background With the rapid development of electric automobiles and portable electronic devices, the number of waste lithium batteries increases exponentially. And lithium is taken as a scarce strategic resource, and the efficient recycling of the lithium is a key problem to be solved urgently in the industry. Therefore, developing efficient and green waste lithium battery recovery technology is important for ensuring strategic resource safety and promoting recycling economy. Currently, the dominant recovery techniques mainly include pyrometallurgy and hydrometallurgy. The method has the advantages of high energy consumption, easy loss of lithium in high-temperature slag, low recovery rate and poor selectivity, and the hydrometallurgy (acid leaching-extraction/precipitation) has wider application, but still has significant challenges in the aspect of lithium recovery (1) because a plurality of metal ions (such as cobalt, nickel, manganese and aluminum) in the leaching solution coexist, the physicochemical properties are similar, the traditional precipitation method or solvent extraction method is difficult to realize high-selectivity separation of lithium, so that the purity of lithium products is not high or the recovery flow is long, and (2) the solvent extraction technology is seriously dependent on tributyl phosphate, P507 and other volatile organic solvents and a large amount of acid-base reagents for extraction and back extraction, the organic solvents are inflammable and toxic, have safety and environmental risks, the loss and residues in the process also increase the difficulty and cost of subsequent wastewater treatment, and the green and clean level of the whole process are required to be improved. Therefore, developing a new green recovery process that can efficiently and highly selectively recover lithium and avoid the use of harmful organic solvents as much as possible is a technical problem to be solved in the art. Disclosure of Invention Aiming at the defects of the prior art, the invention aims to provide a method for recovering lithium from waste lithium batteries. The invention adopts the metal organic coordination compound modified by the photosensitive azo group as the lithium ion adsorbent, realizes the greenization and high efficiency of the lithium ion separation and extraction process, can identify and capture lithium ions with high selectivity through the specific coordination structure in an all-aqueous phase system, thereby completely avoiding the environmental and safety problems caused by using volatile and toxic organic solvents in the traditional process, having obvious environmental friendliness, and simultaneously, the photosensitive azo group introduced into the adsorbent has unique light response characteristic, can trigger the controllable release of lithium ions only by ultraviolet irradiation, realizes the clean and low-energy operation of desorption process, and further reduces secondary pollution and reagent consumption. Therefore, the recovery process simplifies the separation process and meets the industrial requirement of green recovery while ensuring the efficient recovery of lithium resources. In order to achieve the aim of the invention, the invention adopts the following technical scheme: The invention provides a method for recovering lithium from waste lithium batteries, which comprises the following steps: and (3) pretreating the waste lithium batteries to obtain the waste lithium battery black material. And mixing the waste lithium battery black material with a leaching agent, and carrying out lithium leaching to obtain a lithium-containing leaching solution. And mixing the lithium-containing leaching solution with a lithium ion adsorbent, and performing adsorption reaction to obtain a lithium-loaded adsorbent precipitate. And (3) carrying out desorption treatment on the adsorbent precipitate loaded with lithium to release lithium ions, thereby obtaining a lithium-rich solution. And carrying out post-treatment on the lithium-rich solution to obtain a lithium product. Wherein the lithium ion adsorbent is a metal organic coordination compound modified by photosensitive azo groups. The invention adopts the metal organic coordination compound modified by the photosensitive azo group as the lithium ion adsorbent, realizes the greenization and high efficiency of the lithium ion separation and extraction process, can identify and capture lithium ions with high selectivity through the specific coordination structure in an all-aqueous phase system, thereby completely avoiding the environmental and safety problems caused by using volatile and toxic organic solvents in the traditional process, having obvious environmental friendliness, and s