Method for recovering black powder of lithium ion battery

Abstract

The invention provides a lithium ion battery black powder recovery method, which comprises: (1) calcining the lithium ion battery black powder to obtain carbon-free black powder, sequentially carrying out leaching and impurity removal on the carbon-free black powder, and adding an organic amine-containing extraction agent for separation to obtain an organic amine-nickel cobalt manganese complex and a lithium liquid; and (2) carrying out hydrothermal reaction treatment on the organic amine-nickel cobalt manganese complex in the step (1) to obtain a nickel cobalt manganese catalyst, and sequentially carrying out concentration and lithium precipitation on the lithium liquid in the step (1) to obtain lithium carbonate. According to the method, the lithium ion battery black powder is subjected to leaching and impurity removal after being calcined, the organic amine-nickel cobalt manganese complex and the lithium liquid are directly obtained through separation by adding the extracting agent containing the organic amine, the step of multi-step extraction in a traditional extraction method is avoided, lithium metal and nickel cobalt manganese metal are directly separated, the recovery process is shortened, and the recovery efficiency is improved. And the nickel-cobalt-manganese catalyst with high added value is obtained.

Description

Technical Field

[0001] The invention belongs to the technical field of lithium battery recycling and relates to a method for recycling black powder of lithium ion batteries. Background Art

[0002] New energy vehicles began to be widely promoted and applied in 2013, and entered a stage of explosive growth in 2014. The scrapping period of power batteries for operating new energy vehicles is 3 to 5 years, and the scrapping period of power batteries for private passenger cars is 5 to 8 years. Due to the surge in power battery installations in 2021, it is expected that the number of battery scrapping will increase rapidly around 2027. Driven by the current high production and sales of new energy vehicles and the relatively tight supply of resources, the tight supply has catalyzed the rise in the prices of metals such as lithium, cobalt and nickel. Therefore, there is an urgent need to recycle and process waste power batteries.

[0003] Conventional recycling processes mainly disassemble waste lithium-ion batteries to obtain black powder rich in metals such as lithium, nickel, cobalt, and manganese. The black powder is then treated with acid leaching, impurity removal, extraction, stripping, and chemical precipitation using a wet recovery method to separate various metal ions and obtain corresponding inorganic metal salts or hydroxides. However, this recycling route is complex, and the separation of manganese, cobalt, and nickel one by one can easily cause the loss of valuable metals such as nickel and lithium, resulting in an overall low metal ion recovery rate.

[0004] CN116565367A discloses a method for the extraction-free regeneration of battery materials, wherein the battery leachate is hydrolyzed to remove impurities, calcium and magnesium are removed by fluoridation, and ion exchange resin is used to remove fluorine to directly obtain a nickel-cobalt-manganese solution, which is further processed to obtain a nickel-cobalt-manganese precursor. This method avoids the traditional complex extraction and separation steps and directly obtains a nickel-cobalt-manganese precursor. However, it does not mention the extraction of lithium ions.

[0005] CN115852152A discloses a method for co-processing battery black powder and nickel cobalt hydroxide, which is to reduce the carbon powder at high temperature - directly immerse in water or CO 2 Improvement of water leaching method. The key is to use nickel cobalt hydroxide with a certain alkalinity to replace flake caustic soda, and precipitate the nickel, cobalt and manganese ions in the slurry after water leaching in the form of hydroxides that are insoluble in water, thereby separating them from lithium metal. This method abandons the traditional complex extraction steps and avoids the use of flake caustic soda, but in the subsequent acid leaching process of cobalt-rich nickel manganese slag, additional concentrated acid needs to be added to oxidize and neutralize the nickel cobalt hydroxide added in the separation step. The final product is still not a sulfate of nickel, cobalt and manganese, and the added value is not high.

[0006] Therefore, how to simplify the recovery of precious metal lithium in lithium-ion batteries and increase the added value of recovered metals nickel, cobalt and manganese is an important research direction in this field. Summary of the invention

[0007] The purpose of the present invention is to provide a method for recycling black powder from lithium-ion batteries, which can simplify the process of recycling precious metal lithium in lithium-ion batteries and at the same time increase the added value of recycling metal nickel, cobalt and manganese.

[0008] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0009] The present invention aims to provide a method for recovering black powder from lithium-ion batteries, the method comprising the following steps:

[0010] (1) calcining lithium-ion battery black powder to obtain carbon-free black powder, leaching and removing impurities from the carbon-free black powder in sequence, and then adding an extractant containing an organic amine to separate the powder to obtain an organic amine-nickel-cobalt-manganese complex and a lithium solution;

[0011] (2) subjecting the organic amine-nickel-cobalt-manganese complex described in step (1) to a hydrothermal reaction treatment to obtain a nickel-cobalt-manganese catalyst, and sequentially concentrating and precipitating lithium from the lithium solution described in step (1) to obtain lithium carbonate.

[0012] The present invention calcines lithium-ion battery black powder, then performs leaching and impurity removal, and then adds an extractant containing an organic amine for separation to directly obtain an organic amine-nickel-cobalt-manganese complex and a lithium solution, thereby avoiding the multi-step extraction steps in a traditional extraction method, directly separating lithium metal and nickel-cobalt-manganese metal, shortening the recovery process, and obtaining a high-value-added nickel-cobalt-manganese catalyst.

[0013] As a preferred technical solution of the present invention, the calcination temperature in step (1) is 400-800°C, and the temperature can be 400°C, 450°C, 500°C, 550°C, 600°C, 650°C, 700°C, 750°C or 800°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0014] Preferably, the calcination time in step (1) is 60 to 180 min, wherein the time can be 60 min, 80 min, 100 min, 120 min, 140 min, 150 min, 160 min or 180 min, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0015] As a preferred technical solution of the present invention, in step (1), the leaching is carried out using an acid leaching solution or an alkaline leaching solution.

[0016] The acid leaching solution includes any one of hydrochloric acid, sulfuric acid, nitric acid, hydrogen peroxide, acetic acid or oxalic acid, or a combination of at least two of them. Typical but non-limiting examples of the combination include: a combination of hydrochloric acid and sulfuric acid, a combination of sulfuric acid and nitric acid, a combination of nitric acid and hydrogen peroxide, a combination of sulfuric acid and hydrogen peroxide, a combination of hydrochloric acid and nitric acid, or a combination of hydrochloric acid, acetic acid and oxalic acid.

[0017] The alkaline leachate includes sodium hydroxide.

[0018] Preferably, the leaching temperature in step (1) is 20-120°C, wherein the temperature can be 20°C, 30°C, 40°C, 50°C, 60°C, 80°C, 90°C, 100°C or 120°C, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0019] Preferably, the leaching time in step (1) is 0.5 to 6 hours, wherein the time can be 0.5 h, 1 h, 1.5 h, 2 h, 2.5 h, 3 h, 3.5 h, 4 h, 4.5 h, 5 h, 5.5 h or 6 h, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0020] Preferably, the solid-liquid ratio of the leaching in step (1) is 1:8 to 1:20, wherein the solid-liquid ratio can be 1:8, 1:10, 1:12, 1:14, 1:15, 1:16, 1:18 or 1:20, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0021] As a preferred technical solution of the present invention, in step (1), the impurity removal adopts a pH regulator, and the pH regulator includes any one of sodium hydroxide, sodium carbonate, ammonia water or ammonium carbonate, or a combination of at least two of them. Typical but non-limiting examples of the combination include: a combination of sodium hydroxide and sodium carbonate, a combination of sodium carbonate and ammonia water, or a combination of ammonia water and ammonium carbonate, etc.

[0022] Preferably, the pH of the impurity removal in step (1) is 3.0-11.0, wherein the pH may be 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0 or 11.0, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0023] Preferably, the temperature for removing impurities in step (1) is 25-65°C, wherein the temperature can be 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, 60°C or 65°C, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0024] Preferably, the time for removing impurities in step (1) is 0.5 to 24 hours, wherein the time can be 0.5 hours, 2 hours, 4 hours, 6 hours, 8 hours, 10 hours, 12 hours, 14 hours, 16 hours, 18 hours, 20 hours, 22 hours or 24 hours, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0025] Preferably, the solid-to-liquid ratio of the impurity removal in step (1) is 1:8 to 1:20, wherein the solid-to-liquid ratio can be 1:8, 1:10, 1:12, 1:14, 1:16, 1:18 or 1:20, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0026] As a preferred technical solution of the present invention, in step (1), the molecular weight of the organic amine is 185-600, wherein the molecular weight can be 185, 200, 220, 240, 260, 280, 300, 320, 340, 360, 380, 400, 420, 440, 460, 480, 500, 520, 540, 560, 580 or 600, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0027] It should be noted that the organic amine of the present invention includes but is not limited to any one or a combination of at least two of dodecylamine with a molecular weight of 185, octadecylamine with a molecular weight of 269, trioctylamine with a molecular weight of 354, hexadecyltrimethylammonium bromide with a molecular weight of 364 and tetraoctylammonium bromide with a molecular weight of 547 known to those skilled in the art, wherein typical but non-limiting examples include: a combination of dodecylamine and octadecylamine, a combination of dodecylamine and trioctylamine, or a combination of octadecylamine, hexadecyltrimethylammonium bromide and tetraoctylammonium bromide, etc. The inorganic base includes sodium hydroxide and / or ammonia water. The organic alcohol includes any one or a combination of at least two of methanol, ethanol, propanol, isopropanol or butanol, wherein typical but non-limiting examples of the combination include: a combination of methanol and ethanol, a combination of ethanol and propanol, a combination of propanol and isopropanol, or a combination of isopropanol and butanol, etc.

[0028] Preferably, the extractant further comprises an organic alcohol.

[0029] Preferably, the extractant further comprises an inorganic base.

[0030] Preferably, the mass ratio of the organic amine, the organic alcohol and the inorganic base is 1:(50-500):(0-10), wherein the mass ratio can be 1:50:2, 1:100:8, 1:100:5, 1:100:10, 1:200:2, 1:200:10, 1:300:4, 1:300:6, 1:500:1, 1:300:0, 1:200:5 or 1:500:10, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0031] The main component of the extractant of the present invention is organic amine, which can be directly used as a reducing agent and surfactant for subsequent hydrothermal reaction treatment. The present invention controls the content of each component in the extractant within the above range, effectively improving the metal extraction rate.

[0032] It should be noted that the inorganic base content of 0 means that no inorganic base is added, that is, the extractant is composed of organic amine and organic alcohol.

[0033] Preferably, the mass ratio of the extractant to the residual liquid after the impurity removal is 1:(5-50), and the mass ratio can be 1:5, 1:10, 1:15, 1:20, 1:25, 1:30, 1:35, 1:40, 1:45 or 1:50, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0034] As a preferred technical solution of the present invention, in step (1), the separation temperature is 25-60°C, wherein the temperature can be 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C or 60°C, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0035] Preferably, the separation time in step (1) is 6 to 36 hours, wherein the time can be 6 hours, 10 hours, 15 hours, 20 hours, 25 hours, 30 hours, 35 hours or 36 hours, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0036] Preferably, the endpoint pH of the separation in step (1) is 7.0-11.0, wherein the pH may be 7.0, 7.5, 8.0, 8.5, 9.0, 9.5, 10.0, 10.5 or 11.0, etc., but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0037] The endpoint pH of separation in the present invention is controlled within the above range, which not only avoids the problem of metal lithium loss due to too high pH, ​​but also prevents the reduction of metal extraction rate due to too low pH.

[0038] As a preferred technical solution of the present invention, in step (2), the solvent used for the hydrothermal reaction treatment includes any one of water, methanol, ethanol, propanol, isopropanol or butanol, or a combination of at least two of them, wherein typical but non-limiting examples of the combination include: a combination of water and methanol, a combination of methanol and ethanol, a combination of ethanol and propanol, a combination of propanol and isopropanol, or a combination of isopropanol and butanol, etc.

[0039] Preferably, the temperature of the hydrothermal reaction treatment in step (2) is 70-200°C, wherein the temperature can be 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, 140°C, 150°C, 160°C, 180°C or 200°C, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0040] Preferably, the time for the hydrothermal reaction treatment in step (2) is 6 to 36 hours, wherein the time can be 6 hours, 10 hours, 15 hours, 20 hours, 24 hours, 25 hours, 30 hours, 35 hours or 36 hours, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0041] Preferably, the average particle size of the nickel-cobalt-manganese catalyst in step (2) is 5 to 500 nm, wherein the average particle size may be 5 nm, 10 nm, 20 nm, 30 nm, 50 nm, 100 nm, 150 nm, 200 nm, 250 nm, 300 nm, 350 nm, 400 nm, 450 nm or 500 nm, etc., but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0042] As a preferred technical solution of the present invention, in step (2), the concentration temperature is 60-100°C, wherein the temperature can be 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C or 100°C, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0043] Preferably, the vacuum degree of concentration in step (2) is 0 to 0.1 Pa, wherein the vacuum degree can be 0Pa, 0.01Pa, 0.02Pa, 0.03Pa, 0.04Pa, 0.05Pa, 0.06Pa, 0.07Pa, 0.08Pa, 0.09Pa or 0.1Pa, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0044] Preferably, after the concentration in step (2), a concentrated lithium solution is obtained, and the lithium ion concentration of the concentrated lithium solution is 10 to 20 g / L, wherein the lithium ion concentration can be 10 g / L, 12 g / L, 14 g / L, 16 g / L, 18 g / L or 20 g / L, etc., but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0045] As a preferred technical solution of the present invention, in step (2), the lithium deposition includes sequentially performing a first lithium deposition and a second lithium deposition.

[0046] The lithium precipitation of the present invention adopts two lithium precipitation treatments, which effectively improves the lithium recovery rate.

[0047] Preferably, the lithium precipitating agents used in the first lithium precipitating and the second lithium precipitating respectively independently include any one of sodium carbonate, sodium bicarbonate, ammonium carbonate, ammonium bicarbonate, carbonic acid or carbon dioxide, or a combination of at least two of them, wherein the typical but non-limiting examples of the combination are: a combination of sodium carbonate and sodium bicarbonate, a combination of sodium bicarbonate and ammonium carbonate, a combination of ammonium carbonate and ammonium bicarbonate, a combination of ammonium bicarbonate and carbonic acid, or a combination of carbonic acid and carbon dioxide, etc. In the present invention, the lithium precipitating agent used in the first lithium precipitating and the lithium precipitating agent used in the second lithium precipitating can be the same or different.

[0048] As a preferred technical solution of the present invention, the temperature of the first lithium precipitate is 70-100°C, wherein the temperature can be 70°C, 75°C, 80°C, 85°C, 90°C, 95°C or 100°C, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0049] Preferably, the first lithium precipitation time is 0.5 to 2 hours, wherein the time may be 0.5 hours, 0.8 hours, 1.0 hours, 1.2 hours, 1.4 hours, 1.6 hours, 1.8 hours or 2 hours, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0050] Preferably, a first lithium precipitation solution is obtained after the first lithium precipitation.

[0051] Preferably, the lithium ion concentration of the first lithium precipitate is 1 to 3 g / L, wherein the lithium ion concentration may be 1 g / L, 1.2 g / L, 1.5 g / L, 2 g / L, 2.3 g / L, 2.5 g / L, 2.8 g / L or 3 g / L, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0052] Preferably, the temperature of the second lithium deposition is 70-100°C, wherein the temperature may be 70°C, 75°C, 80°C, 85°C, 90°C, 95°C or 100°C, etc., but is not limited to the listed values, and other unlisted values ​​are also applicable.

[0053] Preferably, the second lithium precipitation time is 0.5 to 2 hours, wherein the time may be 0.5 hours, 0.8 hours, 1.0 hours, 1.2 hours, 1.4 hours, 1.6 hours, 1.8 hours or 2 hours, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0054] Preferably, after the second lithium precipitation, a second lithium precipitation solution and sodium sulfate are obtained.

[0055] Preferably, the lithium ion concentration of the second lithium precipitate is 10 to 20 g / L, wherein the lithium ion concentration may be 10 g / L, 12 g / L, 13 g / L, 14 g / L, 15 g / L, 16 g / L, 17 g / L, 18 g / L or 20 g / L, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0056] Exemplarily, a method for recycling black powder from lithium-ion batteries provided by the present invention specifically comprises the following steps:

[0057] (1) calcining lithium-ion battery black powder to obtain carbon-free black powder, leaching and removing impurities from the carbon-free black powder in sequence, and then adding an extractant containing an organic amine to separate the powder to obtain an organic amine-nickel-cobalt-manganese complex and a lithium solution;

[0058] The calcination temperature is 400-800°C and the calcination time is 60-180 minutes;

[0059] The leaching temperature is 20 to 120° C., the leaching time is 0.5 to 6 hours, and the solid-liquid ratio is 1:8 to 1:20;

[0060] The pH of the impurity removal is 3.0-11.0, the temperature is 25-65°C, the time is 0.5-24h and the solid-liquid ratio is 1:8-1:20;

[0061] The separation method comprises: using an extractant to separate the impurity-removed residual liquid after impurities are removed, the separation temperature is 25-60° C., the time is 6-36 hours and the end point pH is 7.0-11.0.

[0062] (2) subjecting the organic amine-nickel-cobalt-manganese complex of step (1) to a hydrothermal reaction to obtain a nickel-cobalt-manganese catalyst, and sequentially concentrating and precipitating lithium in the lithium solution of step (1) to obtain lithium carbonate;

[0063] The hydrothermal reaction treatment is performed at a temperature of 70 to 200° C. and for a time of 6 to 36 hours;

[0064] The concentration temperature is 60-100°C and the vacuum degree is 0-0.1Pa;

[0065] The lithium precipitation includes a first lithium precipitation and a second lithium precipitation carried out sequentially, wherein the temperature of the first lithium precipitation is 70-100°C and the time is 0.5-2h, and a first lithium precipitation solution is obtained after the first lithium precipitation, and the lithium ion concentration of the first lithium precipitation solution is 1-3g / L, and the temperature of the second lithium precipitation is 70-100°C and the time is 0.5-2h, and a second lithium precipitation solution is obtained after the second lithium precipitation, and the concentration of the second lithium precipitation solution is 10-20g / L.

[0066] The method for recycling black powder from lithium-ion batteries disclosed in the present invention is applied to the field of recycling and processing of waste power batteries.

[0067] Compared with the prior art, the present invention has the following beneficial effects:

[0068] (1) The method for recovering lithium battery black powder provided by the present invention does not require the traditional multiple distribution extraction steps and the subsequent reprocessing and preparation process of nickel-cobalt-manganese sulfate, and can directly separate lithium metal and nickel-cobalt-manganese metal to obtain lithium carbonate and high value-added nano-scale nickel-cobalt-manganese catalyst, respectively, which simplifies the recovery of precious metal lithium in lithium-ion battery black powder and increases the added value of strategic metal nickel-cobalt-manganese;

[0069] (2) The purity of lithium carbonate in the present invention can be as high as 85.0-99.99%, and the particle size of the recovered nano nickel-cobalt-manganese catalyst can reach 5-500 nm. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] Figure 1 This is the method for recovering black powder from lithium-ion batteries described in Examples 1 to 5 of the present invention. DETAILED DESCRIPTION

[0071] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0072] Example 1

[0073] This embodiment provides a Figure 1 The method for recycling black powder of lithium-ion batteries shown in the figure comprises the following steps:

[0074] (1) Lithium-ion battery black powder is calcined at 600° C. for 120 min to obtain carbon-free black powder, and the carbon-free black powder is leached and impurity-removed in sequence, and then an extractant containing an organic amine is added to separate the powder to obtain an organic amine-nickel-cobalt-manganese complex and a lithium solution, wherein the specific methods of leaching, impurity removal and separation are as follows:

[0075] Leaching: hydrochloric acid was used for leaching, the leaching temperature was 70°C, the time was 3h and the solid-liquid ratio was 1:14;

[0076] Impurity removal: The pH regulator for impurity removal is sodium hydroxide, the pH of impurity removal is 7.0, the temperature is 45°C, the time is 12h, and the solid-liquid ratio is 1:14;

[0077] Separation: The impurity-removed residual liquid was separated by using an extractant (a mixture of octadecylamine with a molecular weight of 269, methanol and sodium hydroxide in a mass ratio of 1:200:10). The mass ratio of the extractant to the impurity-removed residual liquid was 1:30. The separation temperature was 42°C, the time was 21 hours, and the pH was 9.0.

[0078] (2) adding water to the organic amine-nickel-cobalt-manganese complex in step (1) and subjecting it to a hydrothermal reaction treatment at a temperature of 135° C. for a time of 21 h to obtain a nickel-cobalt-manganese catalyst;

[0079] (3) The lithium solution in step (1) is sequentially concentrated and lithium is precipitated to obtain lithium carbonate and sodium sulfate, wherein the specific methods of concentration and lithium precipitation are as follows:

[0080] Concentration: The concentration temperature is 80°C and the vacuum degree is 0.05Pa;

[0081] Lithium precipitation: lithium precipitation includes a first lithium precipitation and a second lithium precipitation in sequence, the lithium precipitation agents of the first lithium precipitation and the second lithium precipitation are both sodium carbonate, the temperature of the first lithium precipitation is 85°C, the time is 1 hour, and the first lithium precipitation liquid is obtained after the first lithium precipitation, and the lithium ion concentration of the first lithium precipitation liquid is 2g / L, the temperature of the second lithium precipitation is 85°C, the time is 1 hour, and the second lithium precipitation liquid is obtained after the second lithium precipitation, and the concentration of the second lithium precipitation liquid is 15g / L.

[0082] Example 2

[0083] This embodiment provides a Figure 1 The method for recycling black powder of lithium-ion batteries shown in the figure comprises the following steps:

[0084] (1) Lithium-ion battery black powder is calcined at 400° C. for 180 min to obtain carbon-free black powder, and the carbon-free black powder is leached and impurity-removed in sequence, and then an extractant containing an organic amine is added to separate the powder to obtain an organic amine-nickel-cobalt-manganese complex and a lithium solution, wherein the specific methods of leaching, impurity removal and separation are as follows:

[0085] Leaching: Sulfuric acid was used for leaching at a temperature of 20°C, a time of 6 hours, and a solid-liquid ratio of 1:8;

[0086] Impurity removal: The pH regulator for impurity removal is sodium carbonate, the pH of impurity removal is 3.0, the temperature is 25°C, the time is 24h, and the solid-liquid ratio is 1:8;

[0087] Separation: The impurity-removed residual liquid was separated by using an extractant (a mixture of dodecylamine with a molecular weight of 185, methanol and sodium hydroxide in a mass ratio of 1:100:5). The mass ratio of the extractant to the impurity-removed residual liquid was 1:10. The separation temperature was 25°C, the time was 36 hours, and the pH was 7.0.

[0088] (2) adding water to the organic amine-nickel-cobalt-manganese complex of step (1) and subjecting it to a hydrothermal reaction treatment at a temperature of 70° C. and a time of 36 hours to obtain a nickel-cobalt-manganese catalyst;

[0089] (3) The lithium solution in step (1) is sequentially concentrated and lithium is precipitated to obtain lithium carbonate and sodium sulfate, wherein the specific methods of concentration and lithium precipitation are as follows:

[0090] Concentration: The concentration temperature is 60°C and the vacuum degree is 0Pa;

[0091] Lithium precipitation: lithium precipitation includes a first lithium precipitation and a second lithium precipitation in sequence, the lithium precipitation agents of the first lithium precipitation and the second lithium precipitation are ammonium carbonate, the temperature of the first lithium precipitation is 70°C, the time is 0.5h, and the first lithium precipitation solution is obtained after the first lithium precipitation, and the lithium ion concentration of the first lithium precipitation solution is 1g / L, the temperature of the second lithium precipitation is 70°C, the time is 0.5h, and the second lithium precipitation solution is obtained after the second lithium precipitation, and the concentration of the second lithium precipitation solution is 10g / L.

[0092] Example 3

[0093] This embodiment provides a Figure 1 The method for recycling black powder of lithium-ion batteries shown in the figure comprises the following steps:

[0094] (1) Lithium-ion battery black powder is calcined at 800° C. for 60 min to obtain carbon-free black powder, and the carbon-free black powder is sequentially leached and impurity-removed, and then an extractant containing an organic amine is added to separate the powder to obtain an organic amine-nickel-cobalt-manganese complex and a lithium solution, wherein the specific methods of leaching, impurity removal and separation are as follows:

[0095] Leaching: Use hydrogen peroxide for leaching, the leaching temperature is 100℃, the time is 0.5h, and the solid-liquid ratio is 1:20;

[0096] Impurity removal: The pH regulator for impurity removal is ammonium carbonate, the pH for impurity removal is 11.0, the temperature is 65°C, the time is 0.5h, and the solid-liquid ratio is 1:20;

[0097] Separation: Use an extractant (a mixture of tetraoctylammonium bromide with a molecular weight of 547, methanol and sodium hydroxide in a mass ratio of 1:300:4) to separate the residual liquid after impurity removal. The mass ratio of the extractant to the residual liquid is 1:40, the separation temperature is 60°C, the time is 6 hours, and the pH is 11.0.

[0098] (2) adding water to the organic amine-nickel-cobalt-manganese complex of step (1) for hydrothermal reaction at a temperature of 200° C. for 6 h to obtain a nickel-cobalt-manganese catalyst;

[0099] (3) The lithium solution in step (1) is sequentially concentrated and lithium is precipitated to obtain lithium carbonate and sodium sulfate, wherein the specific methods of concentration and lithium precipitation are as follows:

[0100] Concentration: The concentration temperature is 60°C and the vacuum degree is 0.1Pa;

[0101] Lithium precipitation: lithium precipitation includes a first lithium precipitation and a second lithium precipitation in sequence, the lithium precipitation agents of the first lithium precipitation and the second lithium precipitation are both sodium bicarbonate, the temperature of the first lithium precipitation is 100°C, the time is 2h, and the first lithium precipitation solution is obtained after the first lithium precipitation, and the lithium ion concentration of the first lithium precipitation solution is 3g / L, the temperature of the second lithium precipitation is 100°C, the time is 2h, and the second lithium precipitation solution is obtained after the second lithium precipitation, and the concentration of the second lithium precipitation solution is 20g / L.

[0102] Example 4

[0103] Except that no sodium hydroxide was added to the extractant, other conditions in this embodiment were the same as those in Example 1.

[0104] Example 5

[0105] In this example, except that the mass ratio of the extractant to the impurity-removing liquid is changed from 1:30 to 1:60, other conditions are the same as those in Example 1.

[0106] Example 6

[0107] In this embodiment, except that the lithium deposition is replaced by: the temperature is 85° C. and the lithium is deposited for 2 hours, the other conditions are the same as those in embodiment 1.

[0108] Example 7

[0109] Except that the hydrothermal reaction treatment temperature is 60° C., other conditions in this embodiment are the same as those in Example 1.

[0110] The purity of the lithium carbonate recovered in Examples 1-7 was tested, and the particle size of the nickel, cobalt and manganese was tested. The test results are shown in Table 1.

[0111] Table 1

[0112] serial number Lithium recovery rate Lithium carbonate purity Particle size of nickel, cobalt and manganese Example 1 93.7％ 99.6％ 100~200nm Example 2 92.5％ 89％ 100~200nm Example 3 93.1％ 99.3％ 100~200nm Example 4 87.1％ 87％ 100~200nm Example 5 89.1％ 85％ 600~1000nm Example 6 85％ 81.2％ 650~900nm Example 7 92.8％ 99.4％ -

[0113] It is not difficult to see from Table 1 that the lithium recovery rate in Examples 1 to 3 is high, and the purity of the product lithium carbonate is relatively high, and nano-scale nickel-cobalt-manganese products are also obtained. In Example 4, since the extractant used in the separation process does not add auxiliary agents such as organic alcohols and inorganic bases, the recovery rate and purity of lithium carbonate are reduced. In Example 5, since the amount of extractant added is too low, the organic amine-nickel-cobalt-manganese complex and the lithium liquid cannot be fully separated, so that the purity of lithium carbonate is lower than that of Example 1. In Example 6, only one lithium precipitation is used. Compared with the two lithium precipitations in Example 1, the lithium recovery rate in Example 6 is significantly reduced, which in turn affects the overall product quality. In Example 7, due to the low hydrothermal reaction temperature, no nickel-cobalt product is obtained (the "-" in the table means not detected).

[0114] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for recycling black powder from lithium-ion batteries, characterized in that: The method comprises the following steps: (1) calcining lithium-ion battery black powder to obtain carbon-free black powder, leaching and removing impurities from the carbon-free black powder in sequence, and then adding an extractant containing an organic amine to separate the powder to obtain an organic amine-nickel-cobalt-manganese complex and a lithium solution; (2) subjecting the organic amine-nickel-cobalt-manganese complex described in step (1) to a hydrothermal reaction treatment to obtain a nickel-cobalt-manganese catalyst, and sequentially concentrating and precipitating lithium from the lithium solution described in step (1) to obtain lithium carbonate.

2. The method according to claim 1, characterized in that: In step (1), the calcination temperature is 400-800°C; Preferably, the calcination time in step (1) is 60 to 180 minutes.

3. The method according to claim 1 or 2, characterized in that: In step (1), the leaching is carried out using an acid leaching solution or an alkaline leaching solution; Preferably, the leaching temperature in step (1) is 20 to 120°C; Preferably, the leaching time in step (1) is 0.5 to 6 hours; Preferably, the solid-to-liquid ratio of the leaching in step (1) is 1:8 to 1:

20.

4. The method according to any one of claims 1 to 3, characterized in that: In step (1), the impurity removal is performed using a pH adjuster, wherein the pH adjuster comprises any one of sodium hydroxide, sodium carbonate, ammonia water or ammonium carbonate, or a combination of at least two thereof; Preferably, the pH of the impurity removal in step (1) is 3.0 to 11.0; Preferably, the temperature of the impurity removal in step (1) is 25 to 65°C; Preferably, the time for removing impurities in step (1) is 0.5 to 24 hours; Preferably, the solid-to-liquid ratio of the impurity removal in step (1) is 1:8 to 1:

20.

5. The method according to any one of claims 1 to 4, characterized in that: In step (1), the molecular weight of the organic amine is 185 to 600; Preferably, the extractant further comprises an organic alcohol; Preferably, the extractant further comprises an inorganic base; Preferably, the mass ratio of the organic amine, organic alcohol and inorganic base is 1:(50-500):(0-10); Preferably, the mass ratio of the extractant to the residual liquid after the impurity removal is 1:(5-50).

6. The method according to any one of claims 1 to 5, characterized in that: In step (1), the separation temperature is 25 to 60° C.; Preferably, the separation time in step (1) is 6 to 36 hours; Preferably, the endpoint pH of the separation in step (1) is 7.0 to 11.

0.

7. The method according to any one of claims 1 to 6, characterized in that: In step (2), the solvent used for the hydrothermal reaction treatment includes any one of water, methanol, ethanol, propanol, isopropanol or butanol, or a combination of at least two thereof; Preferably, the temperature of the hydrothermal reaction treatment in step (2) is 70 to 200° C. Preferably, the hydrothermal reaction treatment time in step (2) is 6 to 36 hours; Preferably, the average particle size of the nickel-cobalt-manganese catalyst in step (2) is 5 to 500 nm.

8. The method according to any one of claims 1 to 7, characterized in that: In step (2), the concentration temperature is 60 to 100° C.; Preferably, the vacuum degree of the concentration in step (2) is 0 to 0.1 Pa; Preferably, after the concentration in step (2), a concentrated lithium solution is obtained, and the lithium ion concentration of the concentrated lithium solution is 10 to 20 g / L.

9. The method according to any one of claims 1 to 8, characterized in that: The lithium deposition in step (2) comprises sequentially performing a first lithium deposition and a second lithium deposition; Preferably, the lithium precipitating agents used in the first lithium precipitating and the second lithium precipitating respectively and independently include any one of sodium carbonate, sodium bicarbonate, ammonium carbonate, ammonium bicarbonate, carbonic acid or carbon dioxide, or a combination of at least two thereof.

10. The method according to claim 9, characterized in that The temperature of the first lithium deposition is 70-100° C. Preferably, the first lithium precipitation time is 0.5 to 2 hours; Preferably, after the first lithium precipitation, a first lithium precipitation solution is obtained; Preferably, the lithium ion concentration of the first lithium precipitation solution is 1 to 3 g / L; Preferably, the temperature of the second lithium deposition is 70-100° C.; Preferably, the second lithium precipitation time is 0.5 to 2 hours; Preferably, after the second lithium precipitation, a second lithium precipitation solution and sodium sulfate are obtained; Preferably, the lithium ion concentration of the second lithium precipitation solution is 10-20 g / L.

Images