Method for preferentially extracting lithium and manganese from waste lncm materials

Abstract

The application belongs to the field of battery material recycling, and specifically discloses a method for preferentially extracting lithium and manganese from waste LNCM material, which comprises the following steps: loading and sealing raw material solution containing waste LNCM material and alkali in a pressure-resistant container chamber, heating to a temperature T, then introducing an oxygen-containing atmosphere to increase the pressure to P, and performing leaching treatment under insulation and pressure preservation; then, pressure relief and temperature reduction are performed, solid-liquid separation is performed, and leaching solution rich in lithium and manganese and leaching residue rich in nickel and cobalt are obtained; the pressure P in the leaching treatment stage is 1.1-5 times the system pressure in the pressurization initial stage, and the T is 200-350 DEG C. According to the method, high-selectivity separation of lithium, manganese, nickel and cobalt in the ternary material can be realized.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of battery waste recycling, and particularly relates to the field of waste lithium battery material recycling. BACKGROUND

[0002] Due to the life limitation of lithium ion batteries, in recent years, the wide application of portable electronic devices and new energy vehicles will generate a large amount of waste lithium ion batteries. It is estimated that more than 11 million tons of lithium ion batteries will be discarded worldwide by 2023. Waste lithium ion batteries contain harmful organic chemicals that are harmful to the environment and human health. In addition, waste lithium ion batteries contain a large amount of valuable metals, and the content of these metals is higher than that of natural ores. Therefore, in order to protect the environment and save resources, it is urgent to efficiently and sustainably recycle waste lithium ion batteries.

[0003] At present, for the recycling of waste LNCM materials, most of the work mainly recovers the main valuable metals from waste cathode active materials through traditional pyrometallurgy, hydrometallurgy and biometallurgy, and the combination of the two. The existing recycling ideas of waste LNCM materials mainly obtain a nickel-cobalt-manganese leaching solution after pre-extracting lithium (such as CN116495716A, CN114956130A, etc.), or directly acid leaching LNCM materials to obtain a nickel-cobalt-manganese leaching solution (such as TW200408155A, CN101603126A, etc.). It can be seen that most of the existing processes co-leach nickel, cobalt and manganese, however, the properties of manganese and nickel-cobalt are similar, and the subsequent separation and extraction is difficult, and there are few schemes in the industry that can separate nickel, cobalt and lithium-manganese in one step with high selectivity. SUMMARY

[0004] In view of the problems existing in the recycling of waste lithium ion battery anodes, the application aims to provide a method for preferentially extracting lithium and manganese from waste LNCM materials, which can preferentially and selectively extract lithium and manganese from waste ternary anode materials.

[0005] A method for preferentially extracting lithium and manganese from waste LNCM materials, a raw material solution containing waste LNCM materials and alkali is loaded and sealed in a pressure-resistant container chamber, heated to a temperature T, and then an oxygen-containing atmosphere is introduced to increase the pressure to P, and leaching treatment is carried out under insulation and pressure; then, the pressure is released, the temperature is lowered, and solid-liquid separation is carried out to obtain a leaching solution enriched with lithium and manganese and a leaching residue enriched with nickel and cobalt;

[0006] The pressure P in the leaching treatment stage is 1.1-5 times the system pressure in the pressurization initial stage, and the T is 200-350 DEG C.

[0007] The waste LNCM material and alkali are subjected to gas-solid-liquid three-phase leaching treatment under an oxygen-containing atmosphere, and the temperature and the pressure of the oxygen-containing atmosphere during the treatment are jointly controlled, so that the lithium and manganese can be selectively extracted, and the lithium, manganese, nickel and cobalt can be selectively separated.

[0008] In the application, the waste LNCM material can be recovered from waste ternary batteries based on known means, for example, the waste ternary lithium ion battery can be discharged, disassembled and peeled (such as organic solvent NMP peeling) to obtain waste positive electrode powder.

[0009] In the application, the active material in the waste LNCM material can be an oxidized lithium salt of nickel, cobalt and manganese in any proportion, for example, can contain at least one of NCM811, NCM523, NCM111 and the like.

[0010] In the application, considering the simplicity of the process, the waste lithium ion battery positive electrode material can also contain at least one of a conductive agent, a binder and an electrolyte.

[0011] In the application, the content of the active material of the waste LNCM material is not particularly required, and considering the economy of the process, the content of the active material in the waste LNCM material is not less than 50wt.%, preferably 80-95wt.%.

[0012] In the application, the alkali is at least one of sodium hydroxide and potassium hydroxide.

[0013] In the application, the alkali is more than 5 times, preferably 10-20 times, and further 10-15 times the weight of the LNCM active material in the waste LNCM material.

[0014] In the application, the liquid-solid ratio in the raw material solution is not particularly required, and considering the treatment cost and effect, it can be further 15-25g / mL.

[0015] In the application, the raw material solution is loaded and sealed in the pressure-resistant container under an oxygen-containing atmosphere;

[0016] In the application, the oxygen-containing atmosphere is an oxygen-containing gas atmosphere, which is at least one of oxygen, air and oxygen-protective gas mixed gas.

[0017] Preferably, in the oxygen-containing atmosphere, the system partial pressure of oxygen is not less than 10v%, preferably not less than 20v%;

[0018] In the application, in the initial stage of leaching, the volume content of the raw material solution is not particularly required, and considering the treatment efficiency and value of the treatment process, it can be further 50-60V%.

[0019] In the present application, the waste LNCM, lye, and gas-solid-liquid three-phase treatment process in oxygen-containing atmosphere are further combined with the joint control of temperature and pressure in the treatment stage, which is the key to realizing the efficient and preferential extraction of lithium and manganese. In the present application, the initial pressure during pressurization is the pressure of the pressure-resistant system at the initial temperature during pressurization, which can be measured by existing pressure measuring equipment or calculated by the method of P = nRT / V.

[0020] In the present application, the temperature in the leaching stage is preferably 200-300°C.

[0021] In the present application, the leaching stage includes two treatment processes, which are to preheat the solution to a first-stage temperature T1, then use an oxygen-containing atmosphere to pressurize to 1-1.5 times the initial pressure of the pressurization stage (the system pressure at T1 temperature, for example, P0’ = nRT1 / V), and then heat to a second-stage temperature T2 after holding pressure, and continue to use an oxygen-containing atmosphere to pressurize to 2-2.5 times the initial pressure of the pressurization stage.

[0022] Preferably, in the two-stage treatment stage, the temperature T1 is 200-230°C, and the temperature T2 is 250-280°C.

[0023] In the present application, the leaching treatment stage is 1-5h, and further can be 2-3h. The leaching treatment time is the holding and pressure holding time under the temperature and oxygen-containing atmosphere pressure control.

[0024] In the present application, when using a two-stage leaching process, the holding and pressure holding time of each stage can be 0.5-1.5h.

[0025] In the present application, the leaching solution of lithium and manganese can be separated based on known methods.

[0026] Advantages

[0027] The present application innovatively performs gas-solid-liquid three-phase treatment of waste LNCM materials and lye in an oxygen-containing atmosphere, further combines the joint control of temperature and pressure in the treatment process, which can realize synergy and selectively and preferentially extract lithium and manganese, and can realize high selectivity separation of lithium and manganese and nickel and cobalt.

[0028] In the present application, the two-stage temperature and pressure control treatment can further improve the separation selectivity of lithium and manganese and nickel and cobalt. DETAILED DESCRIPTION

[0029] The present application will be further described in detail below in conjunction with specific embodiments, but the present application is not limited to the following embodiments.

[0030] In the present application, the active material content in the waste old lithium ion battery positive electrode material is not particularly required, and considering the economy of the process, the content is preferably above 50wt.%. In the following cases, the active content is 85-90wt.% unless otherwise stated.

[0031] Example 1:

[0032] Step (1):

[0033] The waste old NCM power nickel-cobalt-manganese lithium battery is placed in 2mol / L brine for 30h discharging treatment, and the discharged battery is dried at 85℃, and the positive electrode sheet and negative electrode sheet are separated, the positive electrode sheet is soaked in N-methyl pyrrolidone, the current collector in the sheet is separated, filtered, washed with water and dried to obtain waste positive electrode powder;

[0034] Step (2):

[0035] The waste positive electrode powder and the analytical pure potassium hydroxide (the weight ratio of active material in the waste positive electrode powder / KOH is 1:12) are mixed uniformly, and the mixture is filled into a high-pressure reaction kettle in an air atmosphere, pure water is added to make the concentration of KOH 600g / L, and the filling volume of the solution in the reaction kettle accounts for 50-55v%.

[0036] Step (3):

[0037] The reaction kettle is sealed, and when the temperature is raised to 200℃ (marked as T), high-purity oxygen is introduced to make the internal gas pressure P 1.5 times the system pressure when pressurized, and the gas-solid-liquid three-phase leaching is carried out at the temperature and pressurized pressure for 120min. After the reaction is completed, the exhaust valve is opened to make the internal and external pressures consistent, and then filtered after cooling to room temperature to obtain lithium-manganese filtrate (leachate) and nickel-cobalt filter residue.

[0038] In the leachate, the extraction rate of lithium is 98.9%, the extraction rate of manganese is 98.5%, and the extraction rate of nickel and cobalt is less than 0.1%.

[0039] Example 2:

[0040] Compared with Example 1, the difference is only that the amount of alkali in step (2) is changed, and the other operations and parameters are the same as in Example 1. The experimental groups are:

[0041] Group A: the weight ratio of active material / KOH is 1:10

[0042] Group B: the weight ratio of active material / KOH is 1:15.

[0043] In the leachate, the extraction rate of lithium in group A is 98.8%, the extraction rate of manganese is 98.3%, and the extraction rate of nickel and cobalt is less than 0.1%.

[0044] The extraction rate of lithium is 99.2%, the extraction rate of manganese is 98.9%, and the extraction rate of nickel and cobalt is less than 0.1%.

[0045] Example 3:

[0046] Compared with Example 1, the difference is only that in step (3), the temperature of T is 330℃, and other operations and parameters are the same as those in Example 1.

[0047] The extraction rate of lithium is 99.5%, the extraction rate of manganese is 99.0%, and the extraction rate of nickel and cobalt is less than 0.1%.

[0048] Example 4:

[0049] Compared with Example 1, the difference is only that in step (3), the temperature is preheated to T1 (220℃), and the system pressure is pressurized to P1 (P1 is the pressure of the system at the beginning of pressurization, for example, P1=1.4P0', and P0' = nRT1 / V) using high-purity oxygen, and then the temperature is increased to T2 (260℃) after 1h of heat preservation and pressure preservation, and the system pressure is pressurized to P2 (P2 is the pressure of the system at the beginning of pressurization, for example, P2=2.2P0'', and P0'' = nRT2 / V) using high-purity oxygen, and then the temperature is increased to T2 (260℃) after 1h of heat preservation and pressure preservation. The subsequent steps are the same as those in Example 1.

[0050] The extraction rate of lithium is 99.9%, the extraction rate of manganese is 99.8%, and the extraction rate of nickel and cobalt is less than 0.05%.

[0051] From Examples 1, 3 and 4, it can be seen that by using the two-stage pressurization method described in the present application, better lithium-manganese combined leaching selectivity can be unexpectedly obtained at a lower temperature.

[0052] Comparative Example 1

[0053] Compared with Example 1, the difference is only that in step 2, KOH is not added, and other operations and parameters are the same as those in Example 1.

[0054] The extraction rate of lithium is 54.7%, and the extraction rate of manganese is 19.6%.

[0055] Comparative Example 2

[0056] Compared with Example 1, the difference is only that in step 3, oxygen is not used for pressure increase treatment. Other operations and parameters are the same as those in Example 1.

[0057] The extraction rate of lithium is 71.8%, and the extraction rate of manganese is 3.7%.

[0058] Comparative Example 3

[0059] The difference compared with Example 1 is only that in step 3, Ar is used instead of the high-purity oxygen for the pressurization treatment, and the other operations and parameters are the same as in Example 1.

[0060] The extraction rate of lithium is 75.3%, and the extraction rate of manganese is 10.9%.

[0061] Comparative Example 4

[0062] The difference compared with Example 1 is only that in step 3, the temperature of T is 150°C, and the other operations and parameters are the same as in Example 1.

[0063] The extraction rate of lithium is 80.6%, and the extraction rate of manganese is 59.4%.

Claims

1. A method for preferentially extracting lithium from waste LNCM material, characterized in that, The raw material solution containing waste LNCM material and alkali is loaded and sealed in a pressure-resistant container chamber, heated to a temperature T, and then pressurized to P by introducing an oxygen-containing atmosphere, and leaching treatment is carried out under isothermal and isobaric conditions; then, the pressure is released, the temperature is lowered, and solid-liquid separation is carried out, to obtain a leaching solution enriched in lithium and manganese and a leaching residue enriched in nickel and cobalt; The pressure P of the leaching treatment stage is 1.1-5 times the system pressure at the start of pressurization, and T is 200-350℃. The waste LNCM material contains at least one of NCM811, NCM523, and NCM111 LNCM active materials. The alkali is more than 5 times the weight of the LNCM active material in the waste LNCM material.

2. The method for preferentially extracting lithium from waste LNCM materials according to claim 1, wherein, The waste LNCM material may also contain at least one of a conductive agent, a binder, a separator, and an electrolyte.

3. The method for preferentially extracting lithium from waste LNCM materials according to claim 1, wherein, The content of the active material in the waste LNCM material is not less than 50wt.%.

4. The method for preferentially extracting lithium from waste LNCM materials according to claim 3, wherein, The content of the active material in the waste LNCM material is 80-95wt.%.

5. The method for preferentially extracting lithium from waste LNCM materials according to claim 1, wherein, The alkali is at least one of sodium hydroxide and potassium hydroxide.

6. The method for preferentially extracting lithium from spent LNCM materials according to claim 1, wherein, The alkali is 10-20 times the weight of the LNCM active material in the waste LNCM material.

7. The method for preferentially extracting lithium from waste LNCM materials according to claim 6, wherein, The alkali is 10-15 times the weight of the LNCM active material in the waste LNCM material.

8. The method for preferentially extracting lithium from spent LNCM materials according to claim 1, wherein, The liquid-solid ratio in the raw material solution is 15-25g / mL.

9. The method for preferentially extracting lithium from spent LNCM materials according to claim 1, wherein, The raw material solution is loaded and sealed in the pressure-resistant container under an oxygen-containing atmosphere.

10. The method for preferentially extracting lithium from spent LNCM materials according to claim 9, wherein, The oxygen-containing atmosphere is an oxygen-containing gas atmosphere, which is at least one of oxygen, air, and oxygen-protective gas mixture.

11. The method for preferentially extracting lithium from spent LNCM materials according to claim 10, wherein, The system partial pressure of oxygen in the oxygen-containing atmosphere is not less than 10v%.

12. The method for preferentially extracting lithium from spent LNCM materials according to claim 11, wherein, The system partial pressure of oxygen in the oxygen-containing atmosphere is not less than 20v%.

13. The method for preferentially extracting lithium from spent LNCM materials according to claim 9, wherein, The oxygen partial pressure of the oxygen-containing atmosphere during the pressurization stage is more than 80v%.

14. The method for preferentially extracting lithium from spent LNCM materials according to claim 1, wherein, The volume content of the raw material solution at the start of leaching is 50-60V%.

15. The method for preferentially extracting lithium from spent LNCM materials according to claim 1, wherein, The leaching stage includes two-stage treatment, which is to preheat the solution to a first-stage temperature T1, then use an oxygen-containing atmosphere to pressurize to 1-1.5 times the pressure at the start of pressurization, heat to a second-stage temperature T2 after isothermal and isobaric treatment, and continue to use an oxygen-containing atmosphere to pressurize to 2-2.5 times the pressure at the start of pressurization; The temperature T1 is 200-230℃, and the temperature T2 is 250-280℃.

16. The method for preferentially extracting lithium from spent LNCM materials according to claim 1, wherein, The leaching treatment stage lasts for 1-5h.