Method for reducing the separation of lithium battery black powder

Abstract

The present disclosure provides a method for reducing and separating lithium battery black powder. A method for reducing and separating lithium battery black powder, the separation method comprising the following steps: S1, a molten salt including NaF-AlF3 base or KF-AlF3 base or NaF-KF-AlF3 base is contained in a graphite crucible, and the black powder and the metal reducing agent are contained in the graphite crucible; S2, the graphite crucible is placed in a stainless steel crucible as a whole; S3, the stainless steel crucible is placed in a high-temperature resistance furnace as a whole, the substance in the graphite crucible is melted by heating, and the stainless steel crucible is rotated at the same time; S4, the stainless steel crucible and the graphite crucible are disassembled, white molten salt and Ni, Mn, Co metal alloy are obtained, by reacting the black powder with the molten salt and the metal reducing agent, the Ni, Co, Mn compound is converted into the corresponding metal alloy in the molten salt and the metal reducing agent, and then deposited at the bottom of the molten salt, finally through the operation such as slagging, the precipitate can be taken out.

Description

Technical Field

[0001] This disclosure relates to the field of lithium battery recycling technology, and in particular to a method for reducing and separating lithium battery black powder. Background Technology

[0002] With the rapid development of the new energy industry, the use of lithium batteries has shown a dramatic increase, resulting in a continuous rise in the number of waste lithium batteries. Waste lithium battery recycling has become an urgent and important task. Recycling valuable metal resources such as lithium, cobalt, and nickel from waste lithium batteries has become a strategic issue for the development of my country's new energy industry.

[0003] Lithium batteries that meet the end-of-life standards are sequentially discharged, disassembled, crushed, and sorted to obtain lithium battery black powder. As a key intermediate product in the recycling of waste lithium batteries, lithium battery black powder is a primary raw material for subsequent harmless treatment and the recovery of valuable resources. Lithium battery black powder is a black or grayish-black powder composed of one or more metallic elements such as lithium, nickel, cobalt, manganese, iron, and phosphorus. It is an intermediate product obtained after pre-treating waste lithium batteries using a specific process.

[0004] Current methods for treating lithium battery black powder mainly include pyrometallurgical and hydrometallurgical processes. Pyrometallurgical recycling uses high temperatures to remove organic matter from lithium batteries while reducing valuable metals. Although the pyrometallurgical process is simple, it usually generates a large amount of harmful gases and dust, posing a serious threat to the environment and human health. Hydrometallurgical recycling selectively extracts metal elements from lithium battery black powder through chemical reactions with solvents, including precipitation or solvent extraction methods, to separate the reduced metal components. The advantage of hydrometallurgical treatment of lithium battery black powder is its high extraction efficiency, but its disadvantages include a long process, large volume of waste liquid, and significant waste liquid hazards. Summary of the Invention

[0005] One of the technical problems that this disclosure aims to solve is that existing pyrometallurgical treatment of black powder produces a large amount of harmful gases and dust, resulting in significant pollution; while wet treatment produces a large amount of waste liquid and involves a cumbersome process.

[0006] To address the aforementioned technical problems, this disclosure provides a method for reducing and separating lithium battery black powder, comprising:

[0007] S1, molten salt containing NaF-AlF3-based, KF-AlF3-based, or NaF-KF-AlF3-based compounds is placed in a graphite tong pot, while black powder and metal reducing agent are placed in the graphite tong pot at the same time;

[0008] S2, Place the graphite crucible entirely into the stainless steel crucible;

[0009] S3, place the stainless steel crucible in a high-temperature resistance furnace, heat it up to melt the material inside the graphite crucible, and rotate the stainless steel crucible at the same time.

[0010] S4, disassemble the stainless steel crucible and the graphite crucible to obtain white molten salt and Ni, Mn and Co metal alloys.

[0011] In some embodiments, in the aforementioned method for reducing and separating lithium battery black powder, when the molten salt in S1 only includes NaF-AlF3-based salt, the molar ratio of NaF to AlF3 is 1.0 to 3.0.

[0012] In some embodiments, in the aforementioned method for reducing and separating lithium battery black powder, when the molten salt in S1 consists only of KF-AlF3 base, the molar ratio of KF to AlF3 is 1.0 to 3.0.

[0013] In some embodiments, in the aforementioned method for reducing and separating lithium battery black powder, when the molten salt in S1 only includes NaF-KF-AlF3-based salt, the molar ratio of NaF+KF and AlF3 is 1.0 to 3.0.

[0014] In some embodiments, the aforementioned method for reducing and separating lithium battery black powder, wherein the metal reducing agent in S1 is one of Zn or Al.

[0015] In some embodiments, in the aforementioned method for reducing and separating lithium battery black powder, a rotating motor is provided on the top of the resistance furnace in S3. The rotating motor is connected to a stainless steel crucible to drive the stainless steel crucible to rotate according to a drive signal.

[0016] In some embodiments, the aforementioned method for reducing and separating lithium battery black powder may include the addition of MgF2 to the black powder in S1 to reduce the viscosity of the molten salt and improve the separation performance of C in the molten salt and black powder; CaF2 may also be added to the black powder to reduce the melting temperature of the molten salt.

[0017] In some embodiments, in the aforementioned method for reducing and separating lithium battery black powder, when the LiF concentration in the white molten salt in S4 reaches 1%, a portion of the white molten salt can be collected to extract lithium salt.

[0018] The present disclosure provides a method for the reduction and separation of lithium battery black powder through the above technical solution. This method involves reacting the black powder with molten salt and a metal reducing agent, causing Ni, Co, and Mn compounds to transform into their corresponding metal alloys within the molten salt and reducing agent. These alloys then deposit at the bottom of the molten salt, and the precipitate can be removed through processes such as slag removal. This achieves the separation of Ni, Co, and Mn from the black powder components without directly reducing the valuable metals in the black powder at high temperatures, which would generate large amounts of harmful gases and dust. It also avoids the need for solvent extraction to separate the metal components, which would produce large amounts of waste liquid. Furthermore, the reduced metal alloys can be used directly depending on the application environment. Attached Figure Description

[0019] Figure 1 This is a flowchart of a method for reducing and separating lithium battery black powder, as disclosed in an embodiment of this disclosure. Detailed Implementation

[0020] To further illustrate the technical means and effects adopted by the present invention to achieve the intended purpose, the following detailed description, in conjunction with preferred embodiments, details the specific implementation methods, features, and effects of the method for reducing and separating lithium battery black powder according to the present invention.

[0021] Example 1

[0022] A method for reducing and separating lithium battery black powder includes the following steps.

[0023] S1. 100g of molten salt composed of NaF-AlF3 base with a molar ratio of NaF to AlF3 of 3 is added to a graphite crucible. At the same time, 20g of metal reducing agent Zn and 25g of black powder 1 are added. Finally, MgF2 and CaF2 are added. At this time, the composition ratio in the graphite crucible is 54% NaF-36% AlF3-5% MgF2-5% CaF2.

[0024] S2, then place the graphite crucible entirely into the stainless steel crucible;

[0025] S3, place the stainless steel crucible in a high-temperature resistance furnace, and use an external temperature controller to heat the furnace to the target temperature of 985℃, so that the substance inside the stainless steel crucible melts and the reaction continues for 0.5 hours.

[0026] S4, disassemble the stainless steel crucible and the graphite crucible to obtain 87g of the upper white molten salt and 36g of Ni, Mn and Co metal alloy;

[0027] Finally, quantitative analysis of the concentrations of Li, Ni, Co, and Mn in the white molten salt and analysis of the concentrations of Li, Ni, Co, and Mn in the metal alloy were performed to obtain the recovery ratios of Li in the upper molten salt and Ni, Co, and Mn in the metal alloy.

[0028] It should be noted here that adding MgF2 improves the viscosity of the molten salt, enhancing the separation performance of carbon (C) from the black powder, thus allowing for the collection of more Ni, Co, and Mn from the black powder. Simultaneously, CaF2 lowers the melting temperature of the molten salt. This means that when heating and melting the stainless steel in a resistance furnace, adding CaF2 reduces the melting temperature of the molten salt, significantly shortening the heating time. Combined with MgF2, this improves the separation performance of C from the black powder, increasing the efficiency of the experiment. Furthermore, during heating in the resistance furnace, an external controller can drive a motor to rotate, causing the stainless steel crucible to rotate inside the furnace, ensuring thorough reaction of the materials within the graphite crucible and achieving full recovery of Ni, Co, and Mn.

[0029] In this embodiment, only black powder, metal reducing agent and molten salt need to be added to a graphite crucible, and then the graphite crucible is placed in a stainless steel crucible. The materials are heated and melted in a high-temperature resistance furnace, which allows Ni, Co and Mn in the black powder to be transformed into corresponding metal alloys in the molten salt and then deposited at the bottom of the molten salt. Finally, the precipitate can be removed by slag removal and other operations, thus completing the separation of Ni, Co and Mn in the black powder. No extra harmful gases or dust or extra waste liquid will be generated. The obtained alloy can be used directly according to specific production needs or subjected to secondary separation.

[0030] Example 2

[0031] A method for reducing and separating lithium battery black powder includes the following steps.

[0032] S1. 100g of molten salt composed of NaF-AlF3 base with a molar ratio of NaF to AlF3 of 3 is added to a graphite crucible. At the same time, 20g of metal reducing agent Zn and 25g of black powder 2 are added. Finally, MgF2 and CaF2 are added. At this time, the composition ratio in the graphite crucible is 54% NaF-36% AlF3-5% MgF2-5% CaF2.

[0033] S2, then place the graphite crucible entirely into the stainless steel crucible;

[0034] S3, place the stainless steel crucible in a high-temperature resistance furnace, and use an external temperature controller to heat the furnace to the target temperature of 985℃, so that the substance inside the stainless steel crucible melts and the reaction continues for 4 hours.

[0035] S4, disassemble the stainless steel crucible and the graphite crucible to obtain 90g of the upper white molten salt and 32g of Ni, Mn and Co metal alloy;

[0036] Finally, quantitative analysis of the concentrations of Li, Ni, Co, and Mn in the white molten salt and analysis of the concentrations of Li, Ni, Co, and Mn in the metal alloy were performed to obtain the recovery ratios of Li in the upper molten salt and Ni, Co, and Mn in the metal alloy.

[0037] In this embodiment, only black powder, metal reducing agent and molten salt need to be added to a graphite crucible, and then the graphite crucible is placed in a stainless steel crucible. The materials are heated and melted in a high-temperature resistance furnace, which allows Ni, Co and Mn in the black powder to be transformed into corresponding metal alloys in the molten salt and then deposited at the bottom of the molten salt. Finally, the precipitate can be removed by slag removal and other operations, thus completing the separation of Ni, CO and Mn in the black powder. No extra harmful gases or dust or extra waste liquid will be generated. The obtained alloy can be used directly according to specific production needs or subjected to secondary separation.

[0038] Example 3

[0039] A method for reducing and separating lithium battery black powder includes the following steps.

[0040] S1. 100g of molten salt composed of NaF-AlF3 groups with a molar ratio of NaF to AlF3 of 3 is added to a graphite crucible. Simultaneously, 20g of metal reducing agent Al and 25g of black powder 1 are added. Finally, MgF2 and CaF2 are added. At this point, the composition ratio in the graphite crucible is: 55.5% NaF - 37% AlF3 - 3% MgF2 - 3% CaF2 - 1.5% Al2O3.

[0041] S2, then place the graphite crucible entirely into the stainless steel crucible;

[0042] S3, the stainless steel crucible is placed in a high-temperature resistance furnace, and the furnace is heated to the target temperature of 995°C by an external temperature controller to melt the substance inside the stainless steel crucible and continue to react for 3.5 hours.

[0043] S4, disassemble the stainless steel crucible and the graphite crucible to obtain 89g of the upper white molten salt and 33g of Ni, Mn and Co metal alloy;

[0044] Finally, quantitative analysis of the concentrations of Li, Ni, Co, and Mn in the white molten salt and analysis of the concentrations of Li, Ni, Co, and Mn in the metal alloy were performed to obtain the recovery ratios of Li in the upper molten salt and Ni, Co, and Mn in the metal alloy.

[0045] It should be noted that in this embodiment, Al2O3 is AlF3 in the molten salt that is gradually generated into Al2O3 under high temperature as the reaction proceeds. At the same time, Al2O3 can lower the initial crystallization temperature of the molten salt, so as to better realize the transformation of the liquid phase into the solid phase, which is beneficial to the experiment.

[0046] In this embodiment, only black powder, metal reducing agent and molten salt need to be added to a graphite crucible, and then the graphite crucible is placed in a stainless steel crucible. The materials are heated and melted in a high-temperature resistance furnace, which allows Ni, Co and Mn in the black powder to be transformed into corresponding metal alloys in the molten salt and then deposited at the bottom of the molten salt. Finally, the precipitate can be removed by slag removal and other operations, thus completing the separation of Ni, Co and Mn in the black powder. No extra harmful gases or dust or extra waste liquid will be generated. The obtained alloy can be used directly according to specific production needs or subjected to secondary separation.

[0047] Example 4

[0048] A method for reducing and separating lithium battery black powder includes the following steps.

[0049] S1. 100g of molten salt composed of NaF-KF-AlF3 groups with a molar ratio of (NaF+KF) to AlF3 of 1.3 is added to a graphite crucible. Simultaneously, 20g of metal reducing agent Zn and 25g of black powder 1 are added. Finally, MgF2 and CaF2 are added. At this point, the composition ratio in the graphite crucible is...

[0050] 44%NaF-10%KF-36%AlF3-5%MgF2-5%CaF2;

[0051] S2, then place the graphite crucible entirely into the stainless steel crucible;

[0052] S3, place the stainless steel crucible in a high-temperature resistance furnace, and use an external temperature controller to heat the furnace to the target temperature of 940°C, so that the substance inside the stainless steel crucible melts and the reaction continues for 2 hours.

[0053] S4, disassemble the stainless steel crucible and the graphite crucible to obtain 90g of the upper white molten salt and 33g of Ni, Mn and Co metal alloy;

[0054] Finally, quantitative analysis of the concentrations of Li, Ni, Co, and Mn in the white molten salt and analysis of the concentrations of Li, Ni, Co, and Mn in the metal alloy were performed to obtain the recovery ratios of Li in the upper molten salt and Ni, Co, and Mn in the metal alloy.

[0055] In this embodiment, only black powder, metal reducing agent and molten salt need to be added to a graphite crucible, and then the graphite crucible is placed in a stainless steel crucible. The materials are heated and melted in a high-temperature resistance furnace, which allows Ni, Co and Mn in the black powder to be transformed into corresponding metal alloys in the molten salt and then deposited at the bottom of the molten salt. Finally, the precipitate can be removed by slag removal and other operations, thus completing the separation of Ni, Co and Mn in the black powder. No extra harmful gases or dust or extra waste liquid will be generated. The obtained alloy can be used directly according to specific production needs or subjected to secondary separation.

[0056] Example 5

[0057] A method for reducing and separating lithium battery black powder includes the following steps.

[0058] S1. 100g of molten salt composed of KF-AlF3 base with a molar ratio of KF to AlF3 of 2.1 is added to a graphite crucible. At the same time, 20g of metal reducing agent Al and 25g of black powder 2 are added. Finally, MgF2 and CaF2 are added. At this time, the composition ratio in the graphite crucible is 54% KF-36% AlF3-5% MgF2-5% CaF2.

[0059] S2, then place the graphite crucible entirely into the stainless steel crucible;

[0060] S3, place the stainless steel crucible in a high-temperature resistance furnace, and use an external temperature controller to heat the furnace to the target temperature of 950°C, so that the substance inside the stainless steel crucible melts and the reaction continues for 4 hours.

[0061] S4, disassemble the stainless steel crucible and the graphite crucible to obtain 91g of the upper white molten salt and 32g of Ni, Mn and Co metal alloy;

[0062] Finally, quantitative analysis of the concentrations of Li, Ni, Co, and Mn in the white molten salt and analysis of the concentrations of Li, Ni, Co, and Mn in the metal alloy were performed to obtain the recovery ratios of Li in the upper molten salt and Ni, Co, and Mn in the metal alloy.

[0063] In this embodiment, only black powder, metal reducing agent and molten salt need to be added to a graphite crucible, and then the graphite crucible is placed in a stainless steel crucible. The materials are heated and melted in a high-temperature resistance furnace, which allows Ni, Co and Mn in the black powder to be transformed into corresponding metal alloys in the molten salt and then deposited at the bottom of the molten salt. Finally, the precipitate can be removed by slag removal and other operations, thus completing the separation of Ni, Co and Mn in the black powder. No extra harmful gases or dust or extra waste liquid will be generated. The obtained alloy can be used directly according to specific production needs or subjected to secondary separation.

[0064] Example 6

[0065] A method for reducing and separating lithium battery black powder includes the following steps.

[0066] S1. 100g of molten salt composed of KF-AlF3 base with a molar ratio of KF to AlF3 of 2.8 is added to a graphite crucible. At the same time, 20g of metal reducing agent Zn and 25g of black powder 2 are added. Finally, MgF2 and CaF2 are added. At this time, the composition ratio in the graphite crucible is 57% KF-28% AlF3-5% MgF2-5% CaF2-5% Al2O3.

[0067] S2, then place the graphite crucible entirely into the stainless steel crucible;

[0068] S3, place the stainless steel crucible in a high-temperature resistance furnace, and use an external temperature controller to heat the furnace to the target temperature of 950°C, so that the substance inside the stainless steel crucible melts and the reaction continues for 2 hours.

[0069] S4, disassemble the stainless steel crucible and the graphite crucible to obtain 89g of the upper white molten salt and 34g of Ni, Mn and Co metal alloy;

[0070] Finally, quantitative analysis of the concentrations of Li, Ni, Co, and Mn in the white molten salt and analysis of the concentrations of Li, Ni, Co, and Mn in the metal alloy were performed to obtain the recovery ratios of Li in the upper molten salt and Ni, Co, and Mn in the metal alloy.

[0071] In this embodiment, only black powder, metal reducing agent and molten salt need to be added to a graphite crucible, and then the graphite crucible is placed in a stainless steel crucible. The materials are heated and melted in a high-temperature resistance furnace, which allows Ni, Co and Mn in the black powder to be transformed into corresponding metal alloys in the molten salt and then deposited at the bottom of the molten salt. Finally, the precipitate can be removed by slag removal and other operations, thus completing the separation of Ni, Co and Mn in the black powder. No extra harmful gases or dust or extra waste liquid will be generated. The obtained alloy can be used directly according to specific production needs or subjected to secondary separation.

[0072] This experiment used two types of battery black powder, namely black powder 1 and black powder 2. The chemical composition of the two black powders is listed in Table 1 and Table 2 below.

[0073] Table 1. Chemical composition analysis results of black powder 1

[0074]

[0075] Table 2. Chemical composition analysis results of black powder 2

[0076]

[0077] It should be noted here that the two types of black powder mentioned above are commonly used in this field, and the black powder with the above component ratio can be directly obtained and separated.

[0078] The recovery ratios of Ni, Co, and Mn in the dry powder mixtures of Examples 1-6 are shown in the table below:

[0079]

[0080]

[0081] In Examples 1 to 8 above, the mass of molten salt is 100g, the mass of black powder is 25g, and the mass of metal reducing agent is 20g. Furthermore, the specific experimental operations in Examples 7 and 8 are the same as those in Example 1, and the specific operations in Example 1 can be referred to.

[0082] A comparison of Examples 1 and 2 shows that the molten salt of Example 1, when using Zn as the metal reducing agent, has a higher recovery rate of Ni, Co, and Mn in black powder 1 compared to black powder 1 and black powder 2. Specifically, the recovery rate of Co is higher, and the reaction time is shorter, only 0.5 h.

[0083] A comparison of Examples 1 and 3 shows that, when using molten salt containing only NaF-AlF3 groups to separate black powder 1, compared to using metal reducing agents Zn and Al, the recovery rate of Ni, Co, and Mn in black powder 1 is higher, the required target temperature is lower, and the reaction time is shorter.

[0084] A comparison of Examples 5 and 6 shows that when molten salt containing only KF-AlF3 groups is used to separate black powder 2, compared with the use of metal reducing agents Zn and Al, the recovery rate of Ni, Co, and Mn in black powder 1 is higher and the reaction time is shorter when using metal reducing agent Zn.

[0085] A comparison of Examples 1 and 4 shows that the recovery rates of Ni, Co, and Mn are basically similar in both examples. However, the target temperature of Example 4 is lower than that of Example 1. Specifically, the addition of KF groups will reduce the melting temperature of the molten salt, thereby reducing the energy consumption of the resistance furnace and greatly improving the efficiency of the reaction.

[0086] Li can dissolve in the molten salt in the form of LiF, which is in the liquid phase. Therefore, the recovery rates of Li in the six embodiments are basically similar. Only when the concentration of LiF inside the graphite crucible is increased to more than 1% by an external detection device can LiF be extracted and collected.

[0087] In summary, it can be understood that at room temperature, Zn has a boiling point of 906℃ and Al has a boiling point of 2327℃. When Zn is used as a reducing agent, it evaporates before reaching the target temperature, leaving only Al in the molten salt's AlF3, resulting in a low Al content in the final alloy. When Al is used as a reducing agent, it does not evaporate but fuses with Ni, Co, and Mn to form an alloy. Therefore, the choice between Zn and Al as reducing agents can be made based on actual production needs. When a higher Al content is required in the alloy, Al can be chosen as the reducing agent; conversely, when a lower Al content is required, Zn can be chosen.

[0088] Meanwhile, in order to better enable the material inside the graphite crucible to react, a rotating motor is installed on the outside of the high-temperature resistance furnace. The rotating motor is connected to the stainless steel crucible inside the high-temperature resistance furnace. It can rotate the stainless steel crucible according to the control signal sent by the external controller, and then rotate the graphite crucible inside the stainless steel crucible. This allows the material inside the graphite crucible to fully contact and react, which is beneficial to the formation of metal alloys.

[0089] This invention utilizes the reaction of black powder and molten salt under the action of a metal reducing agent to transform Ni, Co, and Mn compounds into corresponding metal alloy precipitates in the molten salt, thereby achieving the separation and collection of Ni, Co, and Mn. When NaF-KF-AlF3-based material is used as the molten salt and Zn is used as the metal reducing agent, the recovery rate of Ni in black powder 1 can reach 98%, the recovery rate of Co can reach 91%, and the recovery rate of Mn can reach 97%.

[0090] The embodiments of this disclosure have now been described in detail. To avoid obscuring the concept of this disclosure, some details known in the art have not been described. Those skilled in the art can fully understand how to implement the technical solutions disclosed herein based on the above description.

[0091] While specific embodiments of this disclosure have been described in detail by way of examples, those skilled in the art should understand that the examples are for illustrative purposes only and not intended to limit the scope of this disclosure. Those skilled in the art should understand that modifications can be made to the above embodiments or equivalent substitutions can be made to some technical features without departing from the scope and spirit of this disclosure. In particular, as long as there is no structural conflict, the technical features mentioned in the various embodiments can be combined in any manner.

Claims

1. A method for reducing and separating lithium battery black powder, characterized in that, Includes the following steps: S1, molten salt comprising NaF-AlF3-based, KF-AlF3-based, or NaF-KF-AlF3-based compounds is placed in a graphite tong pot, while black powder and metal reducing agent are placed in the graphite tong pot; S2, the graphite crucible is placed entirely in a stainless steel crucible; S3, the stainless steel crucible is placed in a high-temperature resistance furnace, the temperature is raised to melt the material inside the graphite crucible, and the stainless steel crucible is rotated at the same time. S4, Disassemble the stainless steel crucible and the graphite crucible to obtain white molten salt and Ni, Mn and Co metal alloy; In S1, MgF2 is added to the black powder to reduce the viscosity of the molten salt and improve the separation performance of the molten salt and C in the black powder; CaF2 is also added to the black powder to reduce the melting temperature of the molten salt.

2. The method for reducing and separating lithium battery black powder according to claim 1, characterized in that, When the molten salt in S1 includes only NaF-AlF3-based salts, the molar ratio of NaF to AlF3 is 1.0 to 3.

0.

3. The method for reducing and separating lithium battery black powder according to claim 1, characterized in that, The molten salt in S1 consists only of KF-AlF3-based salts, with a molar ratio of KF to AlF3 of 1.0 to 3.

0.

4. The method for reducing and separating lithium battery black powder according to claim 1, characterized in that, When the molten salt in S1 includes only NaF-KF-AlF3-based salts, the molar ratio of NaF+KF and AlF3 is 1.0~3.

0.

5. The method for reducing and separating lithium battery black powder according to claim 1, characterized in that, The metal reducing agent in S1 is either Zn or Al.

6. The method for reducing and separating lithium battery black powder according to claim 1, characterized in that, The top of the resistance furnace in S3 is equipped with a rotating motor, which is connected to the stainless steel crucible to drive the stainless steel crucible to rotate according to a drive signal.

7. The method for reducing and separating lithium battery black powder according to claim 1, characterized in that, When the LiF concentration in the white molten salt in S4 reaches 1%, a portion of the white molten salt is collected to extract lithium salt.

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