CN116397110A - Method for recycling lithium from waste lithium iron phosphate battery - Google Patents

Method for recycling lithium from waste lithium iron phosphate battery Download PDF

Info

Publication number
CN116397110A
CN116397110A CN202310607912.4A CN202310607912A CN116397110A CN 116397110 A CN116397110 A CN 116397110A CN 202310607912 A CN202310607912 A CN 202310607912A CN 116397110 A CN116397110 A CN 116397110A
Authority
CN
China
Prior art keywords
lithium
leaching
iron
iron phosphate
precipitating
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN202310607912.4A
Other languages
Chinese (zh)
Other versions
CN116397110B (en
Inventor
林庆绪
李英梅
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Kelixin Zhuhai New Energy Co ltd
Original Assignee
Kelixin Zhuhai New Energy Co ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Kelixin Zhuhai New Energy Co ltd filed Critical Kelixin Zhuhai New Energy Co ltd
Priority to CN202310607912.4A priority Critical patent/CN116397110B/en
Publication of CN116397110A publication Critical patent/CN116397110A/en
Application granted granted Critical
Publication of CN116397110B publication Critical patent/CN116397110B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22BPRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B26/00Obtaining alkali, alkaline earth metals or magnesium
    • C22B26/10Obtaining alkali metals
    • C22B26/12Obtaining lithium
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22BPRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B7/00Working up raw materials other than ores, e.g. scrap, to produce non-ferrous metals and compounds thereof; Methods of a general interest or applied to the winning of more than two metals
    • C22B7/006Wet processes
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22BPRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B7/00Working up raw materials other than ores, e.g. scrap, to produce non-ferrous metals and compounds thereof; Methods of a general interest or applied to the winning of more than two metals
    • C22B7/006Wet processes
    • C22B7/007Wet processes by acid leaching
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02WCLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
    • Y02W30/00Technologies for solid waste management
    • Y02W30/50Reuse, recycling or recovery technologies
    • Y02W30/84Recycling of batteries or fuel cells

Abstract

The invention relates to a method for recycling lithium from waste lithium iron phosphate batteries, and belongs to the technical field of lithium battery recycling. According to the invention, after the waste lithium iron phosphate battery is discharged, manual disassembly is carried out, electrolyte is evaporated, ultrasound is carried out in the mixed solution, after aluminum foil is separated, the mixed solution is filtered, filter residues are taken to react with hydrochloric acid in the presence of chlorine, leaching residues and leaching mother liquor are obtained after filtration, leaching mother liquor is added with alkali for reaction and filtration to obtain iron precipitation residues and iron precipitation mother liquor, the leaching residues are continuously subjected to hydrochloric acid reaction step and alkali adding reaction step successively, and finally, the iron phosphate is recovered by combining the two iron precipitation residues, and lithium carbonate is recovered by precipitating lithium of the iron precipitation mother liquor. The mixed solution contains dimethyl sulfoxide, dimethylformamide and polyethylene glycol, and the three components cooperate to promote the dissolution of the binder so as to promote the separation of aluminum foil and active substances and improve the recovery rate of lithium; and leaching the leaching residue A for the second time by using the iron-precipitating mother solution A, so that the concentration of lithium ions in the iron-precipitating mother solution B is increased, and the leaching rate of lithium is increased.

Description

Method for recycling lithium from waste lithium iron phosphate battery
Technical Field
The invention belongs to the technical field of lithium battery recycling, and relates to a method for recycling lithium from waste lithium iron phosphate batteries.
Background
In recent years, new energy automobiles and power storage batteries have been rapidly developed due to the increasing environmental pollution and energy crisis problems, and the power storage batteries include lead-acid storage batteries, nickel-hydrogen power batteries and lithium ion power batteries, wherein the lithium ion power batteries with high energy density and cycle characteristics are known as the best development direction of the power storage batteries in the future. At present, the lithium ion power battery is mainly divided into a ternary power battery and a lithium iron phosphate battery by taking a positive electrode material as a distinction, wherein the lithium iron phosphate battery has the advantages of high energy density, long cycle life, high safety and the like, and is widely applied to the fields of electric automobiles, energy storage systems and the like.
The lithium iron phosphate battery is scrapped after a service life of 8-10 years after a certain cycle times, and the random discarding of the battery can pollute soil, so that the pH value of the environment is increased, and meanwhile, the waste of lithium resources can be caused. The lithium iron phosphate battery material mainly comprises a positive electrode material, a negative electrode material, electrolyte and a diaphragm, wherein the positive electrode material is the most main raw material for effectively recycling lithium resources, a positive electrode plate mainly comprises aluminum foil, lithium iron phosphate positive electrode powder, namely active substances, a binder and a conductive agent, the binder is polyvinylidene fluoride, and the conductive agent is ultrafine carbon powder. The method for recovering lithium from the lithium iron phosphate battery generally comprises a solid-phase method, a liquid-phase method, an oxygen pressure leaching method, a liquid-solid-phase method, a supercritical extraction method and the like, but the existing recovery method has high energy consumption, serious secondary environmental pollution and the recovery rate of lithium is to be improved.
Disclosure of Invention
The invention aims to provide a method for recycling lithium from waste lithium iron phosphate batteries, and belongs to the technical field of lithium battery recycling. According to the invention, the waste lithium iron phosphate battery is discharged and then is manually disassembled, a positive plate is taken to heat and evaporate residual electrolyte, then the electrolyte is placed into a mixed solution for ultrasonic treatment to remove a binder, so that aluminum foil and active substances are separated, the aluminum foil is taken out and washed and recycled, washing liquor is merged into the mixed solution containing the active substances, filter residues are taken to react with hydrochloric acid solution in the presence of chlorine and then filtered, leached slag A and leached mother liquor A are obtained, the leached mother liquor A is subjected to alkali reaction and filtered to obtain iron-precipitating slag A and iron-precipitating mother liquor A, hydrochloric acid solution is added into the iron-precipitating mother liquor A and reacts with the leached slag A under the condition of introducing chlorine, leached mother liquor B is subjected to alkali reaction and filtered to obtain iron-precipitating slag B and iron-precipitating mother liquor B, sodium carbonate is added into the iron-precipitating mother liquor B, and the iron-precipitating slag A and the iron-precipitating slag B are merged and the iron-precipitating slag B are recycled. The mixed solution contains dimethyl sulfoxide, dimethylformamide and polyethylene glycol, and the three components cooperate to promote the dissolution of the binder so as to promote the separation of aluminum foil and active substances and improve the recovery rate of lithium; and leaching the leaching residue A for the second time by using the iron-precipitating mother solution A, so that the concentration of lithium ions in the iron-precipitating mother solution B is increased, and the leaching rate of lithium is increased.
The aim of the invention can be achieved by the following technical scheme:
a method for recovering lithium from a spent lithium iron phosphate battery, the method comprising the steps of:
(1) Discharging the waste lithium iron phosphate battery;
(2) Manually disassembling the discharged waste lithium iron phosphate battery and taking out the positive plate;
(3) Heating the positive plate to evaporate residual electrolyte;
(4) Putting the positive plate from which the electrolyte is evaporated into the mixed solution, heating, performing ultrasonic treatment, and taking out the aluminum foil to obtain slurry;
(5) The aluminum foil is recycled after being washed by water, and the washing liquid is mixed with the slurry to obtain mixed liquid;
(6) Filtering the mixed solution, adding a hydrochloric acid aqueous solution into filter residues under the condition of introducing chlorine, stirring for reaction, and then filtering to obtain leaching residue A and leaching mother liquor A;
(7) Adding sodium hydroxide aqueous solution into the leaching mother liquor A to adjust the pH value of the system to 3-4, stirring and reacting for 1-2h, and then filtering to obtain iron-precipitating slag A and iron-precipitating mother liquor A;
(8) Adding an aqueous hydrochloric acid solution into the iron-precipitating mother solution A until the pH value of the system is 1-2, introducing chlorine, adding leaching slag A, stirring and reacting for 1-2h, and filtering to obtain leaching slag B and leaching mother solution B, wherein the leaching slag B is used for recycling superfine carbon powder;
(9) Adding sodium hydroxide aqueous solution into the leaching mother liquor B to adjust the pH value of the system to 3-4, stirring and reacting for 1-2h, and then filtering to obtain iron-precipitating slag B and iron-precipitating mother liquor B;
(10) And combining the iron-precipitating slag A and the iron-precipitating slag B, recovering iron phosphate, adding sodium carbonate into the iron-precipitating mother solution B, and filtering to obtain lithium carbonate.
As a preferred embodiment of the present invention, the discharging treatment in the step (1) means: immersing the waste lithium iron phosphate battery in a sodium chloride aqueous solution with the mass concentration of 22-30%, completing discharging operation when the battery voltage is reduced to 0.2-0.3V, and taking out the waste lithium iron phosphate battery.
As a preferable technical scheme of the invention, the temperature of the heating in the step (3) is 90-110 ℃, and the evaporation time is controlled to be 2-5h.
As a preferable technical scheme of the invention, the mixed solution in the step (4) comprises dimethyl sulfoxide, dimethylformamide and polyethylene glycol, the molecular weight of the polyethylene glycol is 400-600, the volume ratio of the dimethyl sulfoxide to the dimethylformamide to the polyethylene glycol is 1:0.8-1.8:1.2-2, and the dosage of the mixed solution is controlled to be just immersed into the positive plate.
As a preferable technical scheme of the invention, the temperature of the heating in the step (4) is 40-50 ℃, the ultrasonic frequency is 80-130kHz, and the ultrasonic time is 1-3h.
As a preferable technical scheme of the invention, the volume ratio of the washing liquid to the slurry in the step (5) is 0.8-2:1.
As a preferable technical scheme of the invention, the concentration of the hydrochloric acid aqueous solution in the step (6) is 6-9mol/L, the dosage of the hydrochloric acid aqueous solution is controlled to be just immersed in filter residues, the reaction time is 1.2-2.5h, and the stirring speed is 25-35rpm; the pressure of the reaction in the step (6) and the step (8) is 0.3-0.9MPa.
As a preferable technical scheme of the invention, the mass concentration of the sodium hydroxide aqueous solution in the step (7) and the step (9) is 30-45%, and the adding speed of the sodium hydroxide aqueous solution is controlled to be 8-12mL/min.
As a preferred embodiment of the present invention, the stirring speed in the steps (7), (8) and (9) is 25-35rpm.
As a preferable technical scheme of the invention, the adding amount of the sodium carbonate in the step (10) is controlled to be 10-11 of the pH value of the filtrate after filtering lithium carbonate.
The invention has the beneficial effects that:
(1) The positive plate of the lithium iron phosphate battery consists of aluminum foil, lithium iron phosphate active substances, adhesive polyvinylidene fluoride and conductive agent superfine carbon powder, wherein the adhesive polyvinylidene fluoride is used for bonding the lithium iron phosphate powder and the superfine carbon powder with the aluminum foil; simultaneously, the ultrasonic treatment not only promotes the mixed solution to be fully contacted with the polyvinylidene fluoride, but also promotes the separation of the lithium iron phosphate powder, the superfine carbon powder and the aluminum foil, and finally improves the recovery rate of lithium;
(2) The filter residue after the mixed solution is filtered is lithium iron phosphate containing superfine carbon powder, the filtrate is a mixed solution in which polyvinylidene fluoride is dissolved, the filter residue reacts with hydrochloric acid under the condition of introducing chlorine gas to decompose the lithium iron phosphate, the filtered leaching residue A is the superfine carbon powder and trace undegraded lithium iron phosphate, the leaching mother solution A is added with alkali to be adjusted to a corresponding pH range to precipitate ferric phosphate precipitate, the filtered iron precipitation residue A is the ferric phosphate residue, lithium ions enter the iron precipitation mother solution A, hydrochloric acid is added to the iron precipitation mother solution A to be adjusted to a corresponding pH range to introduce chlorine gas, and the leaching residue A is further added to decompose the residual lithium iron phosphate to continuously push the decomposition reaction to right, so that on one hand, the concentration of lithium ions in the iron precipitation mother solution B can be enriched and improved, the leaching rate of lithium is improved, and meanwhile, the recovery rate of ferric phosphate is also improved;
(3) The aluminum foil does not need to be crushed or smashed and does not need to be calcined, and the whole process can obviously reduce energy consumption; the aluminum foil can be directly recycled, the leaching slag B is used for recycling superfine carbon powder, the iron-precipitating slag A and the iron-precipitating slag B can be combined for recycling ferric phosphate, and finally the lithium carbonate is precipitated.
Detailed Description
In order to further describe the technical means and effects adopted by the present invention for achieving the intended purpose, the following detailed description is given below with reference to the embodiments, structures, features and effects according to the present invention.
Example 1
A method for recovering lithium from a spent lithium iron phosphate battery, the method comprising the steps of:
(1) Immersing the waste lithium iron phosphate battery in a sodium chloride aqueous solution with the mass concentration of 25%, completing discharging operation when the battery voltage is reduced to 0.26V, and taking out the waste lithium iron phosphate battery;
(2) Manually disassembling the discharged waste lithium iron phosphate battery and taking out the positive plate;
(3) Heating the positive plate to 95 ℃ and keeping for 3 hours, and evaporating residual electrolyte;
(4) Putting the positive plate from which the electrolyte is evaporated into a mixed solution, enabling the mixed solution to just submerge the positive plate, heating to 45 ℃, carrying out ultrasonic treatment for 2.5 hours at the frequency of 110kHz, taking out the aluminum foil to obtain slurry, wherein the mixed solution comprises dimethyl sulfoxide, dimethylformamide and polyethylene glycol, the molecular weight of the polyethylene glycol is 400-600, and the volume ratio of the dimethyl sulfoxide to the dimethylformamide to the polyethylene glycol is 1:0.9:1.4;
(5) The aluminum foil is recycled after being washed, the volume ratio of the washed washing liquid to the slurry is controlled to be 0.9:1, and the washing liquid is mixed with the slurry to obtain mixed liquid;
(6) Filtering the mixed solution, adding a hydrochloric acid aqueous solution with the concentration of 7mol/L into filter residues under the condition of introducing chlorine, enabling the hydrochloric acid aqueous solution to just submerge the filter residues, stirring and reacting for 2 hours under the condition of controlling the pressure to be 0.5MPa and the rotating speed of 30rpm, and then filtering to obtain leaching residue A and leaching mother liquor A;
(7) Adding 35% sodium hydroxide aqueous solution at a mass concentration of 10mL/min into the leaching mother liquor A to adjust the pH value of the system to 3-4, stirring at a rotating speed of 30rpm for reaction for 1h, and then filtering to obtain iron slag A and iron slag A;
(8) Adding an aqueous hydrochloric acid solution into the iron-precipitating mother solution A until the pH value of the system is 1-2, controlling the pressure to be 0.5MPa, adding leaching slag A after introducing chlorine, stirring at a rotating speed of 30rpm for reaction for 1.5 hours, and filtering to obtain leaching slag B and leaching mother solution B, wherein the leaching slag B is used for recycling superfine carbon powder;
(9) Adding 35% sodium hydroxide aqueous solution at a speed of 10mL/min into the leaching mother liquor B to adjust the pH value of the system to 3-4, stirring at a rotating speed of 30rpm for reaction for 1.8h, and then filtering to obtain iron slag B and iron slag B;
(10) And (3) combining the iron-precipitating slag A and the iron-precipitating slag B to recover ferric phosphate, adding sodium carbonate into the iron-precipitating mother solution B, filtering to obtain lithium carbonate, and controlling the pH value of the filtered filtrate to be 10-11.
The overall recovery rate of lithium in the positive electrode sheet of this example was 92.87%, and the purity of lithium carbonate was 99.25%.
Example 2
A method for recovering lithium from a spent lithium iron phosphate battery, the method comprising the steps of:
(1) Immersing the waste lithium iron phosphate battery in a sodium chloride aqueous solution with the mass concentration of 22%, completing discharging operation when the battery voltage is reduced to 0.3V, and taking out the waste lithium iron phosphate battery;
(2) Manually disassembling the discharged waste lithium iron phosphate battery and taking out the positive plate;
(3) Heating the positive plate to 110 ℃ and keeping for 2 hours, and evaporating residual electrolyte;
(4) Putting the positive plate from which the electrolyte is evaporated into a mixed solution, enabling the mixed solution to just submerge the positive plate, heating to 40 ℃, carrying out ultrasonic treatment for 3 hours at the frequency of 130kHz, taking out the aluminum foil to obtain slurry, wherein the mixed solution comprises dimethyl sulfoxide, dimethylformamide and polyethylene glycol, the molecular weight of the polyethylene glycol is 400-600, and the volume ratio of the dimethyl sulfoxide to the dimethylformamide to the polyethylene glycol is 1:1.5:2;
(5) The aluminum foil is recycled after being washed, the volume ratio of the washed washing liquid to the slurry is controlled to be 1.5:1, and the washing liquid is mixed with the slurry to obtain mixed liquid;
(6) Filtering the mixed solution, adding a hydrochloric acid aqueous solution with the concentration of 6mol/L into filter residues under the condition of introducing chlorine, enabling the hydrochloric acid aqueous solution to just submerge the filter residues, stirring and reacting for 2.2 hours under the condition of controlling the pressure to be 0.8MPa and the rotating speed of 25rpm, and then filtering to obtain leaching residue A and leaching mother liquor A;
(7) Adding sodium hydroxide aqueous solution with mass concentration of 45% into the leaching mother liquor A at the speed of 8mL/min to adjust the pH value of the system to 3-4, stirring at the rotating speed of 35rpm for reaction for 1h, and then filtering to obtain iron precipitation slag A and iron precipitation mother liquor A;
(8) Adding an aqueous hydrochloric acid solution into the iron-precipitating mother solution A until the pH value of the system is 1-2, controlling the pressure to be 0.8MPa, adding leaching slag A after introducing chlorine, stirring at a rotating speed of 30rpm for reaction for 2 hours, and filtering to obtain leaching slag B and leaching mother solution B, wherein the leaching slag B is used for recycling superfine carbon powder;
(9) Adding a sodium hydroxide aqueous solution with the mass concentration of 30% into the leaching mother solution B at the speed of 12mL/min to adjust the pH value of the system to 3-4, stirring at the rotating speed of 25rpm for reaction for 2 hours, and then filtering to obtain iron slag B and iron slag B;
(10) And (3) combining the iron-precipitating slag A and the iron-precipitating slag B to recover ferric phosphate, adding sodium carbonate into the iron-precipitating mother solution B, filtering to obtain lithium carbonate, and controlling the pH value of the filtered filtrate to be 10-11.
The overall recovery rate of lithium in the positive electrode sheet of this example was 93.15%, and the purity of lithium carbonate was 99.37%.
Example 3
A method for recovering lithium from a spent lithium iron phosphate battery, the method comprising the steps of:
(1) Immersing the waste lithium iron phosphate battery in a sodium chloride aqueous solution with the mass concentration of 30%, completing discharging operation when the battery voltage is reduced to 0.2V, and taking out the waste lithium iron phosphate battery;
(2) Manually disassembling the discharged waste lithium iron phosphate battery and taking out the positive plate;
(3) Heating the positive plate to 90 ℃ and keeping for 5 hours, and evaporating residual electrolyte;
(4) Putting the positive plate from which the electrolyte is evaporated into a mixed solution, enabling the mixed solution to just submerge the positive plate, heating to 50 ℃, performing ultrasonic treatment for 3 hours at the frequency of 80kHz, taking out the aluminum foil to obtain slurry, wherein the mixed solution comprises dimethyl sulfoxide, dimethylformamide and polyethylene glycol, the molecular weight of the polyethylene glycol is 400-600, and the volume ratio of the dimethyl sulfoxide to the dimethylformamide to the polyethylene glycol is 1:1.8:1.2;
(5) The aluminum foil is recycled after being washed, the volume ratio of washing liquid to slurry after washing is controlled to be 2:1, and the washing liquid is mixed into the slurry to obtain mixed liquid;
(6) Filtering the mixed solution, adding a hydrochloric acid aqueous solution with the concentration of 9mol/L into filter residues under the condition of introducing chlorine, enabling the hydrochloric acid aqueous solution to just submerge the filter residues, stirring and reacting for 2.5h under the condition of controlling the pressure to be 0.3MPa and the rotating speed of 35rpm, and then filtering to obtain leaching residue A and leaching mother liquor A;
(7) Adding a sodium hydroxide aqueous solution with the mass concentration of 30% into the leaching mother solution A at the speed of 12mL/min to adjust the pH value of the system to 3-4, stirring at the rotating speed of 25rpm for 2 hours, and then filtering to obtain iron slag A and iron slag A;
(8) Adding an aqueous hydrochloric acid solution into the iron-precipitating mother solution A until the pH value of the system is 1-2, controlling the pressure to be 0.4MPa, adding leaching slag A after introducing chlorine, stirring at a rotating speed of 25rpm for reaction for 2 hours, and filtering to obtain leaching slag B and leaching mother solution B, wherein the leaching slag B is used for recycling superfine carbon powder;
(9) Adding a sodium hydroxide aqueous solution with the mass concentration of 40% into the leaching mother solution B at the speed of 8mL/min to adjust the pH value of the system to 3-4, stirring at the rotating speed of 35rpm for reaction for 1.2h, and then filtering to obtain iron slag B and iron slag B;
(10) And (3) combining the iron-precipitating slag A and the iron-precipitating slag B to recover ferric phosphate, adding sodium carbonate into the iron-precipitating mother solution B, filtering to obtain lithium carbonate, and controlling the pH value of the filtered filtrate to be 10-11.
The overall recovery rate of lithium in the positive electrode sheet of this example was 92.24%, and the purity of lithium carbonate was 99.19%.
Comparative example 1
A method for recovering lithium from a spent lithium iron phosphate battery, the method comprising the steps of:
(1) Immersing the waste lithium iron phosphate battery in a sodium chloride aqueous solution with the mass concentration of 30%, completing discharging operation when the battery voltage is reduced to 0.2V, and taking out the waste lithium iron phosphate battery;
(2) Manually disassembling the discharged waste lithium iron phosphate battery and taking out the positive plate;
(3) Heating the positive plate to 90 ℃ and keeping for 5 hours, and evaporating residual electrolyte;
(4) Putting the positive plate from which the electrolyte is evaporated into a mixed solution, enabling the mixed solution to just submerge the positive plate, heating to 50 ℃, performing ultrasonic treatment for 3 hours at the frequency of 80kHz, taking out the aluminum foil to obtain slurry, wherein the mixed solution comprises dimethyl sulfoxide and polyethylene glycol, the molecular weight of the polyethylene glycol is 400-600, and the volume ratio of the dimethyl sulfoxide to the polyethylene glycol is 2.8:1.2;
(5) The aluminum foil is recycled after being washed, the volume ratio of washing liquid to slurry after washing is controlled to be 2:1, and the washing liquid is mixed into the slurry to obtain mixed liquid;
(6) Filtering the mixed solution, adding a hydrochloric acid aqueous solution with the concentration of 9mol/L into filter residues under the condition of introducing chlorine, enabling the hydrochloric acid aqueous solution to just submerge the filter residues, stirring and reacting for 2.5h under the condition of controlling the pressure to be 0.3MPa and the rotating speed of 35rpm, and then filtering to obtain leaching residue A and leaching mother liquor A;
(7) Adding a sodium hydroxide aqueous solution with the mass concentration of 30% into the leaching mother solution A at the speed of 12mL/min to adjust the pH value of the system to 3-4, stirring at the rotating speed of 25rpm for 2 hours, and then filtering to obtain iron slag A and iron slag A;
(8) Adding an aqueous hydrochloric acid solution into the iron-precipitating mother solution A until the pH value of the system is 1-2, controlling the pressure to be 0.4MPa, adding leaching slag A after introducing chlorine, stirring at a rotating speed of 25rpm for reaction for 2 hours, and filtering to obtain leaching slag B and leaching mother solution B, wherein the leaching slag B is used for recycling superfine carbon powder;
(9) Adding a sodium hydroxide aqueous solution with the mass concentration of 40% into the leaching mother solution B at the speed of 8mL/min to adjust the pH value of the system to 3-4, stirring at the rotating speed of 35rpm for reaction for 1.2h, and then filtering to obtain iron slag B and iron slag B;
(10) And (3) combining the iron-precipitating slag A and the iron-precipitating slag B to recover ferric phosphate, adding sodium carbonate into the iron-precipitating mother solution B, filtering to obtain lithium carbonate, and controlling the pH value of the filtered filtrate to be 10-11.
The overall recovery rate of lithium in the positive plate of this comparative example was 88.67%, and the purity of lithium carbonate was 98.37%.
Comparative example 2
A method for recovering lithium from a spent lithium iron phosphate battery, the method comprising the steps of:
(1) Immersing the waste lithium iron phosphate battery in a sodium chloride aqueous solution with the mass concentration of 30%, completing discharging operation when the battery voltage is reduced to 0.2V, and taking out the waste lithium iron phosphate battery;
(2) Manually disassembling the discharged waste lithium iron phosphate battery and taking out the positive plate;
(3) Heating the positive plate to 90 ℃ and keeping for 5 hours, and evaporating residual electrolyte;
(4) Putting the positive plate from which the electrolyte is evaporated into a mixed solution, enabling the mixed solution to just submerge the positive plate, heating to 50 ℃, performing ultrasonic treatment for 3 hours at the frequency of 80kHz, taking out the aluminum foil to obtain slurry, wherein the mixed solution comprises dimethylformamide and polyethylene glycol, the molecular weight of the polyethylene glycol is 400-600, and the volume ratio of the dimethylformamide to the polyethylene glycol is 2.8:1.2;
(5) The aluminum foil is recycled after being washed, the volume ratio of washing liquid to slurry after washing is controlled to be 2:1, and the washing liquid is mixed into the slurry to obtain mixed liquid;
(6) Filtering the mixed solution, adding a hydrochloric acid aqueous solution with the concentration of 9mol/L into filter residues under the condition of introducing chlorine, enabling the hydrochloric acid aqueous solution to just submerge the filter residues, stirring and reacting for 2.5h under the condition of controlling the pressure to be 0.3MPa and the rotating speed of 35rpm, and then filtering to obtain leaching residue A and leaching mother liquor A;
(7) Adding a sodium hydroxide aqueous solution with the mass concentration of 30% into the leaching mother solution A at the speed of 12mL/min to adjust the pH value of the system to 3-4, stirring at the rotating speed of 25rpm for 2 hours, and then filtering to obtain iron slag A and iron slag A;
(8) Adding an aqueous hydrochloric acid solution into the iron-precipitating mother solution A until the pH value of the system is 1-2, controlling the pressure to be 0.4MPa, adding leaching slag A after introducing chlorine, stirring at a rotating speed of 25rpm for reaction for 2 hours, and filtering to obtain leaching slag B and leaching mother solution B, wherein the leaching slag B is used for recycling superfine carbon powder;
(9) Adding a sodium hydroxide aqueous solution with the mass concentration of 40% into the leaching mother solution B at the speed of 8mL/min to adjust the pH value of the system to 3-4, stirring at the rotating speed of 35rpm for reaction for 1.2h, and then filtering to obtain iron slag B and iron slag B;
(10) And (3) combining the iron-precipitating slag A and the iron-precipitating slag B to recover ferric phosphate, adding sodium carbonate into the iron-precipitating mother solution B, filtering to obtain lithium carbonate, and controlling the pH value of the filtered filtrate to be 10-11.
The comprehensive recovery rate of lithium in the positive plate of the comparative example is 87.83%, and the purity of lithium carbonate is 98.24%.
Comparative example 3
A method for recovering lithium from a spent lithium iron phosphate battery, the method comprising the steps of:
(1) Immersing the waste lithium iron phosphate battery in a sodium chloride aqueous solution with the mass concentration of 30%, completing discharging operation when the battery voltage is reduced to 0.2V, and taking out the waste lithium iron phosphate battery;
(2) Manually disassembling the discharged waste lithium iron phosphate battery and taking out the positive plate;
(3) Heating the positive plate to 90 ℃ and keeping for 5 hours, and evaporating residual electrolyte;
(4) Putting the positive plate from which the electrolyte is evaporated into a mixed solution, enabling the mixed solution to just submerge the positive plate, heating to 50 ℃, performing ultrasonic treatment for 3 hours at the frequency of 80kHz, taking out the aluminum foil to obtain slurry, wherein the mixed solution contains dimethyl sulfoxide and dimethylformamide, and the volume ratio of the dimethyl sulfoxide to the dimethylformamide is 1:3;
(5) The aluminum foil is recycled after being washed, the volume ratio of washing liquid to slurry after washing is controlled to be 2:1, and the washing liquid is mixed into the slurry to obtain mixed liquid;
(6) Filtering the mixed solution, adding a hydrochloric acid aqueous solution with the concentration of 9mol/L into filter residues under the condition of introducing chlorine, enabling the hydrochloric acid aqueous solution to just submerge the filter residues, stirring and reacting for 2.5h under the condition of controlling the pressure to be 0.3MPa and the rotating speed of 35rpm, and then filtering to obtain leaching residue A and leaching mother liquor A;
(7) Adding a sodium hydroxide aqueous solution with the mass concentration of 30% into the leaching mother solution A at the speed of 12mL/min to adjust the pH value of the system to 3-4, stirring at the rotating speed of 25rpm for 2 hours, and then filtering to obtain iron slag A and iron slag A;
(8) Adding an aqueous hydrochloric acid solution into the iron-precipitating mother solution A until the pH value of the system is 1-2, controlling the pressure to be 0.4MPa, adding leaching slag A after introducing chlorine, stirring at a rotating speed of 25rpm for reaction for 2 hours, and filtering to obtain leaching slag B and leaching mother solution B, wherein the leaching slag B is used for recycling superfine carbon powder;
(9) Adding a sodium hydroxide aqueous solution with the mass concentration of 40% into the leaching mother solution B at the speed of 8mL/min to adjust the pH value of the system to 3-4, stirring at the rotating speed of 35rpm for reaction for 1.2h, and then filtering to obtain iron slag B and iron slag B;
(10) And (3) combining the iron-precipitating slag A and the iron-precipitating slag B to recover ferric phosphate, adding sodium carbonate into the iron-precipitating mother solution B, filtering to obtain lithium carbonate, and controlling the pH value of the filtered filtrate to be 10-11.
The overall recovery rate of lithium in the positive plate of the comparative example was 85.07%, and the purity of lithium carbonate was 98.09%.
Comparative example 4
A method for recovering lithium from a spent lithium iron phosphate battery, the method comprising the steps of:
(1) Immersing the waste lithium iron phosphate battery in a sodium chloride aqueous solution with the mass concentration of 30%, completing discharging operation when the battery voltage is reduced to 0.2V, and taking out the waste lithium iron phosphate battery;
(2) Manually disassembling the discharged waste lithium iron phosphate battery and taking out the positive plate;
(3) Heating the positive plate to 90 ℃ and keeping for 5 hours, and evaporating residual electrolyte;
(4) Putting the positive plate from which the electrolyte is evaporated into a mixed solution, enabling the mixed solution to just submerge the positive plate, heating to 50 ℃, performing ultrasonic treatment for 3 hours at the frequency of 80kHz, taking out the aluminum foil to obtain slurry, wherein the mixed solution comprises dimethyl sulfoxide, dimethylformamide and polyethylene glycol, the molecular weight of the polyethylene glycol is 400-600, and the volume ratio of the dimethyl sulfoxide to the dimethylformamide to the polyethylene glycol is 1:1.8:1.2;
(5) The aluminum foil is recycled after being washed, the volume ratio of washing liquid to slurry after washing is controlled to be 2:1, and the washing liquid is mixed into the slurry to obtain mixed liquid;
(6) Filtering the mixed solution, adding a hydrochloric acid aqueous solution with the concentration of 9mol/L into filter residues under the condition of introducing chlorine gas, enabling the hydrochloric acid aqueous solution to just submerge the filter residues, controlling the pressure to be 0.3MPa, stirring and reacting for 2.5h at the speed of 35rpm, and then filtering to obtain leaching residues and leaching mother liquor, wherein the leaching residues are used for recycling superfine carbon powder;
(7) Adding 30% sodium hydroxide aqueous solution at a mass concentration of 12mL/min into the leaching mother liquor, regulating the pH value of the system to 3-4, stirring at a rotating speed of 25rpm for reaction for 2 hours, and then filtering to obtain iron slag and iron slag mother liquor;
(8) The iron-precipitating slag is used for recovering ferric phosphate, sodium carbonate is added into the iron-precipitating mother liquor, lithium carbonate is obtained by filtering, and the pH value of the filtered filtrate is controlled to be 10-11.
The comprehensive recovery rate of lithium in the positive plate of the comparative example is 82.35%, and the purity of lithium carbonate is 99.08%.
The present invention is not limited to the above embodiments, but is capable of modification and variation in detail, and other modifications and variations can be made by those skilled in the art without departing from the scope of the present invention.

Claims (10)

1. A method for recovering lithium from a spent lithium iron phosphate battery, the method comprising the steps of:
(1) Discharging the waste lithium iron phosphate battery;
(2) Manually disassembling the discharged waste lithium iron phosphate battery and taking out the positive plate;
(3) Heating the positive plate to evaporate residual electrolyte;
(4) Putting the positive plate from which the electrolyte is evaporated into the mixed solution, heating, performing ultrasonic treatment, and taking out the aluminum foil to obtain slurry;
(5) The aluminum foil is recycled after being washed by water, and the washing liquid is mixed with the slurry to obtain mixed liquid;
(6) Filtering the mixed solution, adding a hydrochloric acid aqueous solution into filter residues under the condition of introducing chlorine, stirring for reaction, and then filtering to obtain leaching residue A and leaching mother liquor A;
(7) Adding sodium hydroxide aqueous solution into the leaching mother liquor A to adjust the pH value of the system to 3-4, stirring and reacting for 1-2h, and then filtering to obtain iron-precipitating slag A and iron-precipitating mother liquor A;
(8) Adding an aqueous hydrochloric acid solution into the iron-precipitating mother solution A until the pH value of the system is 1-2, introducing chlorine, adding leaching slag A, stirring and reacting for 1-2h, and filtering to obtain leaching slag B and leaching mother solution B, wherein the leaching slag B is used for recycling superfine carbon powder;
(9) Adding sodium hydroxide aqueous solution into the leaching mother liquor B to adjust the pH value of the system to 3-4, stirring and reacting for 1-2h, and then filtering to obtain iron-precipitating slag B and iron-precipitating mother liquor B;
(10) And combining the iron-precipitating slag A and the iron-precipitating slag B, recovering iron phosphate, adding sodium carbonate into the iron-precipitating mother solution B, and filtering to obtain lithium carbonate.
2. The method for recovering lithium from a waste lithium iron phosphate battery according to claim 1, wherein the discharging treatment in the step (1) is: immersing the waste lithium iron phosphate battery in a sodium chloride aqueous solution with the mass concentration of 22-30%, completing discharging operation when the battery voltage is reduced to 0.2-0.3V, and taking out the waste lithium iron phosphate battery.
3. The method for recovering lithium from waste lithium iron phosphate battery according to claim 1, wherein the temperature of the temperature rise in the step (3) is 90-110 ℃, and the evaporation time is controlled to be 2-5h.
4. The method for recovering lithium from waste lithium iron phosphate batteries according to claim 1, wherein the mixed solution in the step (4) comprises dimethyl sulfoxide, dimethylformamide and polyethylene glycol, the molecular weight of the polyethylene glycol is 400-600, the volume ratio of the dimethyl sulfoxide to the dimethylformamide to the polyethylene glycol is 1:0.8-1.8:1.2-2, and the dosage of the mixed solution is controlled to be just immersed in a positive plate.
5. The method for recovering lithium from waste lithium iron phosphate batteries according to claim 1, wherein the temperature of the temperature rise in the step (4) is 40-50 ℃, the ultrasonic frequency is 80-130kHz, and the ultrasonic time is 1-3h.
6. The method for recovering lithium from waste lithium iron phosphate batteries according to claim 1, wherein the volume ratio of the washing liquid to the slurry in the step (5) is 0.8-2:1.
7. The method for recovering lithium from waste lithium iron phosphate batteries according to claim 1, wherein the concentration of the aqueous hydrochloric acid solution in the step (6) is 6-9mol/L, the amount of the aqueous hydrochloric acid solution is controlled to be just immersed in filter residues, the reaction time is 1.2-2.5h, and the stirring speed is 25-35rpm; the pressure of the reaction in the step (6) and the step (8) is 0.3-0.9MPa.
8. The method for recovering lithium from waste lithium iron phosphate batteries according to claim 1, wherein the mass concentration of the sodium hydroxide aqueous solution in the step (7) and the step (9) is 30-45%, and the adding speed of the sodium hydroxide aqueous solution is controlled to be 8-12mL/min.
9. The method for recovering lithium from waste lithium iron phosphate battery according to claim 1, wherein the stirring speed in step (7), step (8) and step (9) is 25-35rpm.
10. The method for recovering lithium from waste lithium iron phosphate batteries according to claim 1, wherein the addition amount of sodium carbonate in the step (10) is controlled to be 10-11 of the pH value of the filtrate after filtering lithium carbonate.
CN202310607912.4A 2023-05-26 2023-05-26 Method for recycling lithium from waste lithium iron phosphate battery Active CN116397110B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202310607912.4A CN116397110B (en) 2023-05-26 2023-05-26 Method for recycling lithium from waste lithium iron phosphate battery

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202310607912.4A CN116397110B (en) 2023-05-26 2023-05-26 Method for recycling lithium from waste lithium iron phosphate battery

Publications (2)

Publication Number Publication Date
CN116397110A true CN116397110A (en) 2023-07-07
CN116397110B CN116397110B (en) 2023-10-31

Family

ID=87020110

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202310607912.4A Active CN116397110B (en) 2023-05-26 2023-05-26 Method for recycling lithium from waste lithium iron phosphate battery

Country Status (1)

Country Link
CN (1) CN116397110B (en)

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103962018A (en) * 2014-05-07 2014-08-06 云南云天化股份有限公司 Polyvinylidene fluoride reinforced microporous membrane and preparation method thereof
CN107739830A (en) * 2017-10-16 2018-02-27 福州大学 A kind of recovery method of positive material of waste lithium iron phosphate
CN112110432A (en) * 2020-08-28 2020-12-22 深圳供电局有限公司 Recovery and regeneration method of lithium iron phosphate anode material of lithium ion battery
AU2019269518A1 (en) * 2018-05-18 2021-01-07 Outotec (Finland) Oy Method for recovering lithium hydroxide
CN112331949A (en) * 2020-11-12 2021-02-05 郑州中科新兴产业技术研究院 Method for recovering phosphorus, iron and lithium from waste lithium iron phosphate batteries
CN113603120A (en) * 2021-08-21 2021-11-05 福州大学 Method for recovering battery-grade lithium from waste lithium iron phosphate through short-process acid leaching
CN115744940A (en) * 2022-11-15 2023-03-07 四川长虹格润环保科技股份有限公司 Method for recovering valuable metals from waste lithium iron phosphate positive electrode powder

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103962018A (en) * 2014-05-07 2014-08-06 云南云天化股份有限公司 Polyvinylidene fluoride reinforced microporous membrane and preparation method thereof
CN107739830A (en) * 2017-10-16 2018-02-27 福州大学 A kind of recovery method of positive material of waste lithium iron phosphate
AU2019269518A1 (en) * 2018-05-18 2021-01-07 Outotec (Finland) Oy Method for recovering lithium hydroxide
CN112110432A (en) * 2020-08-28 2020-12-22 深圳供电局有限公司 Recovery and regeneration method of lithium iron phosphate anode material of lithium ion battery
CN112331949A (en) * 2020-11-12 2021-02-05 郑州中科新兴产业技术研究院 Method for recovering phosphorus, iron and lithium from waste lithium iron phosphate batteries
CN113603120A (en) * 2021-08-21 2021-11-05 福州大学 Method for recovering battery-grade lithium from waste lithium iron phosphate through short-process acid leaching
CN115744940A (en) * 2022-11-15 2023-03-07 四川长虹格润环保科技股份有限公司 Method for recovering valuable metals from waste lithium iron phosphate positive electrode powder

Also Published As

Publication number Publication date
CN116397110B (en) 2023-10-31

Similar Documents

Publication Publication Date Title
CN113061723B (en) Method for recovering lithium from waste lithium iron phosphate batteries and preparing iron phosphate
US6261712B1 (en) Method of reclaiming cathodic active material of lithium ion secondary battery
CN111411366B (en) Method for recovering metal ions in lithium iron phosphate waste through solid-phase electrolysis
CN112374511A (en) Method for preparing lithium carbonate and ternary precursor by recycling waste ternary lithium battery
CN111392750A (en) Method for removing impurities and recovering lithium from waste lithium ion batteries
CN114655969B (en) Method for preparing lithium carbonate and iron phosphate by recycling high-impurity lithium iron phosphate positive electrode waste material
CN111697282B (en) Method for extracting lithium from dilute solution recovered from waste battery positive electrode material
CN106848473A (en) A kind of selective recovery method of lithium in waste lithium iron phosphate battery
CN113912033A (en) Method for recycling anode and cathode mixed powder of waste lithium iron phosphate battery with pre-positioned lithium extraction
KR100644902B1 (en) High-rate recovery of valuable metals such as cobalt and lithium from waste lithium secondary batteries
CN109004307A (en) The recyclable device of valuable metal in waste and old nickel cobalt manganese lithium ion battery
CN113603120A (en) Method for recovering battery-grade lithium from waste lithium iron phosphate through short-process acid leaching
CN111994926A (en) Environment-friendly recovery method of lithium ion battery anode material
CN115149140B (en) Method for recovering iron and lithium from waste lithium iron phosphate batteries
CN116397110B (en) Method for recycling lithium from waste lithium iron phosphate battery
CN115161483B (en) Method for fully recycling waste lithium ion batteries and realizing metal separation
CN115744864A (en) Method for efficiently recycling and reusing waste lithium iron phosphate battery positive electrode material
CN100389520C (en) Method for removing sodium ion from recovered nickle sulfate solution of waste nickle-hydrogen and nickle-cadmium
CN115784188A (en) Method for recycling and preparing battery-grade iron phosphate
CN217323729U (en) System for ferric phosphate contains full element resourceful treatment of ammonia nitrogen waste water
CN114512737A (en) Novel oxidation lithium leaching method for waste lithium iron phosphate
CN113666397A (en) Method for economically recycling lithium from waste lithium iron phosphate material by acid process
CN113809423A (en) Comprehensive utilization method of waste lithium iron phosphate battery
CN114566729B (en) Comprehensive recovery method of waste lithium iron phosphate battery
CN115784324B (en) Method for recycling and preparing ternary positive electrode material precursor by using waste ternary lithium battery

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant