Method for recovering valuable metals from waste ternary lithium battery cathode material

Abstract

This invention provides a method for recovering valuable metals from waste ternary lithium battery cathode materials. The recovery method includes: (1) reducing and leaching the black powder of waste ternary lithium battery cathode materials to obtain a leaching slurry, and removing impurities from the leaching slurry to obtain a ternary leachate; (2) extracting the ternary leachate to remove calcium and copper to obtain an organic phase loaded with calcium and copper and a raffinate after calcium and copper extraction; (3) treating the raffinate after calcium and copper extraction with resin to remove fluoride and phosphorus to obtain a solution after fluoride and phosphorus removal; (4) co-extracting the solution after fluoride and phosphorus removal with nickel, cobalt, and manganese to obtain a mixed solution containing nickel, cobalt, and manganese and a lithium-containing solution. The recovery method provided by this invention has a high recovery rate of valuable metals, thorough separation of impurities, and yields a battery-grade mixed solution of nickel, cobalt, and manganese that can be directly used to prepare ternary precursors. It also achieves lithium recovery. The recovery method is simple, efficient, and has low environmental pollution.

Description

Technical Field

[0001] This invention belongs to the field of battery recycling technology and relates to a method for recycling valuable metals in the cathode material of waste ternary lithium batteries. Background Technology

[0002] With the popularization of new energy vehicles, the number of waste ternary lithium batteries has increased dramatically. Among them, ternary black powder (mainly composed of lithium nickel cobalt manganese oxide, graphite, etc.) is rich in valuable metals such as nickel, cobalt, manganese and lithium, and has high recycling value.

[0003] Currently, the mainstream recycling process for ternary lithium black powder is the hydrometallurgical route. Its core steps typically include acid leaching, impurity removal, and subsequent extraction and separation. Among these, the extraction and separation stage is crucial in determining the recovery rate of valuable metals and the purity of the final product.

[0004] Existing technologies for treating ternary black powder leachate mostly employ a "stepwise extraction" mode. This mode typically first uses extractants such as P204 to extract impurities such as iron, aluminum, and zinc under high acidity conditions, and preliminarily separates calcium and magnesium; then, extractants such as P507 or Cyanex 272 are used to sequentially separate valuable metals such as cobalt, nickel, and manganese under specific pH conditions.

[0005] However, in practical applications, the above-mentioned traditional processes still have the following technical defects:

[0006] (1) The process is lengthy and the recovery rate of valuable metals is low: Due to the limited selectivity of the extractant, especially the poor separation effect on alkaline earth metals such as calcium and magnesium, the process has to adopt a lengthy process of "removing impurities first and then extracting". During the stepwise extraction process, some valuable metals (especially manganese and lithium) are easily lost through co-extraction or entrainment in the washing and back-extraction stages, resulting in a low overall recovery rate.

[0007] (2) High reagent consumption and high production cost: Stepwise extraction mode requires the use of multiple extractants (such as P204, P507, Cyanex272, etc.) for different metals, and in order to meet the saponification requirements of each extractant, a large amount of ammonia or sodium hydroxide is required. Especially when removing calcium and magnesium impurities, due to the high stability of the complexes formed by calcium and magnesium with the extractant, back-extraction is difficult. High concentrations of acid are often required for multi-stage back-extraction, or multiple washing-extraction cycles are used to avoid interference of calcium and magnesium with subsequent nickel-cobalt-manganese co-extraction. This not only greatly increases the consumption of acid and alkali reagents, but also significantly prolongs the process and reduces production efficiency.

[0008] (3) High environmental pressure and high risk of secondary pollution: The complex and lengthy step-by-step extraction process is accompanied by the generation of a large amount of wastewater, including raffinate, washing liquid, back-extraction liquid and saponification wastewater. These wastewaters contain high concentrations of salt, ammonia nitrogen or organic pollutants, are costly to treat, and pose a risk of secondary pollution.

[0009] Currently, traditional recycling processes suffer from problems such as complex procedures, low recovery rates of valuable metals, and incomplete separation of impurities. In particular, impurities such as calcium can affect the efficiency of subsequent nickel-cobalt-manganese co-extraction and product purity.

[0010] Therefore, developing an efficient and simple ternary black powder recovery process to reduce pollution and improve the recovery rate of valuable metals is an urgent technical problem to be solved. Summary of the Invention

[0011] To address the shortcomings of existing technologies, the present invention aims to provide a method for recovering valuable metals from waste ternary lithium-ion battery cathode materials. The method for recovering valuable metals from waste ternary lithium-ion battery cathode materials provided by the present invention employs a specific process and sequence of steps and sequences, including reduction leaching, impurity removal, calcium and copper removal through extraction, resin defluorination, and phosphorus-nickel-cobalt-manganese co-extraction. This effectively avoids interference from calcium in subsequent extraction processes, resulting in high valuable metal recovery rates and thorough impurity separation. The resulting battery-grade nickel-cobalt-manganese mixed solution can be directly used to prepare ternary precursors. Furthermore, it achieves the recovery of lithium, a valuable metal. The recovery method is simple, efficient, and has minimal environmental pollution.

[0012] To achieve this objective, the present invention employs the following technical solution:

[0013] This invention provides a method for recycling valuable metals from waste ternary lithium battery cathode materials, the recycling method comprising the following steps:

[0014] (1) The black powder of the cathode material of the waste ternary lithium battery is reduced and leached to obtain a leaching slurry. The leaching slurry is then treated to remove impurities to obtain a ternary leachate.

[0015] (2) Extract the ternary leachate from step (1) to remove calcium and copper, and obtain an organic phase loaded with calcium and copper and a raffinate after calcium and copper removal.

[0016] (3) The raffinate after calcium and copper extraction in step (2) is subjected to resin defluorination and phosphorus treatment to obtain a solution after defluorination and phosphorus treatment;

[0017] (4) Perform nickel-cobalt-manganese co-extraction treatment on the solution after removing fluoride and phosphorus in step (3) to obtain a mixed solution containing nickel, cobalt and manganese and a lithium-containing solution.

[0018] Preferably, the reduction leaching in step (1) includes:

[0019] The waste ternary lithium battery cathode material black powder, acid solution and reducing agent are mixed and leached to obtain leaching slurry.

[0020] Preferably, in step (1), the pH value of the mixed solution is 1 to 1.5.

[0021] Preferably, in step (1), the acid solution includes a sulfuric acid solution with a concentration of 1 mol / L to 5 mol / L.

[0022] Preferably, in step (1), the temperature of the reduction leaching is 70℃~80℃.

[0023] Preferably, the method for removing impurities in step (1) includes alkaline leaching.

[0024] Preferably, the mass concentration of the alkaline solution in the alkaline leaching for impurity removal is 20% to 25%.

[0025] Preferably, the pH value of the alkaline leaching for impurity removal is 4.5~5.

[0026] Preferably, the total concentration of nickel, cobalt and manganese metal ions in the ternary leachate in step (1) is 60 g / L to 80 g / L.

[0027] Preferably, the extractant used in step (2) for calcium removal includes saponified P204.

[0028] Preferably, the extractant used in step (2) for calcium removal includes a calcium extraction extractant, wherein the dilution rate of the calcium extraction extractant is 11% to 13% and the saponification value of the calcium extraction extractant is 0.01 mol / L to 0.05 mol / L.

[0029] Preferably, the ratio of the O / A phase for extracting calcium and copper in step (2) is (1~1.2):1.

[0030] Preferably, the pH value of the raffinate after calcium and copper extraction in step (2) is 3 to 3.5.

[0031] Preferably, the resin in step (3) comprises a resin containing aminophosphonic acid groups.

[0032] Preferably, in the process of defluorination and phosphorus removal using resin in step (3), the height to diameter ratio of the resin adsorption column is (10~15):1.

[0033] Preferably, in the defluorination and phosphorus treatment process described in step (3), the flow rate of the liquid is 1 BV / h to 2 BV / h.

[0034] Preferably, after the fluoride and phosphorus removal treatment in step (3) is completed, a resin regeneration treatment is performed, wherein the resin regenerator includes a hydrochloric acid solution with a mass fraction of 5% to 8%.

[0035] Preferably, the extractant used in the co-extraction process of step (4) includes HBL116 extractant;

[0036] Preferably, in the extraction process described in step (4), the ratio of O phase to A phase is (5~10):1.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] The present invention provides a method for recovering valuable metals from waste ternary lithium battery cathode materials. After reduction acid leaching, the black powder of the waste ternary lithium battery cathode material can be reduced from insoluble metal oxides to low-valence metal ions (such as lithium, nickel, cobalt, manganese, and other impurity ions). Further impurity removal treatment effectively removes impurities such as iron and aluminum, and the filter residue is a waste residue containing graphite, iron, aluminum, calcium, etc., achieving preliminary impurity removal. Then, extraction is performed to remove calcium and copper, which avoids calcium and copper ions reacting with phosphorus ions during subsequent resin impurity removal. Fluoride ions form insoluble precipitates that clog resin pores, extending resin lifespan by more than 30%. Further phosphorus and fluoride removal from the resin effectively reduces the concentration of phosphorus and fluoride ions in the feed solution, preventing them from forming stable complexes with the extractant during subsequent co-extraction and increasing the nickel-cobalt-manganese extraction rate by more than 5%. Finally, nickel-cobalt-manganese co-extraction ensures that the concentration of impurity ions in the feed solution is minimized, improving the purity of nickel, cobalt, and manganese in the back-extraction solution and recovering a lithium-containing solution. This also completes the extraction of lithium ions, a valuable metal, meeting the requirements for battery-grade products. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the process flow of the recycling method provided in Embodiment 1 of the present invention. Detailed Implementation

[0040] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention.

[0041] The "range" disclosed in this invention can be defined in the form of a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of the specific range. This type of range definition can include or exclude endpoints; any endpoint can be independently included or excluded, and they can be arbitrarily combined, meaning any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60~120 and 80~110 are listed for specific parameters, it is understood that ranges of 60~110 and 80~120 are also expected. Furthermore, if minimum range values ​​1 and 2 are listed, and maximum range values ​​3, 4, and 5 are also listed, then the following ranges are all expected: 1~3, 1~4, 1~5, 2~3, 2~4, and 2~5. In this invention, unless otherwise stated, the numerical range "a~b" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0~5" indicates that all real numbers between "0" and "5" have been listed in this article; "0~5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is described as an integer ≥2, it is equivalent to listing integers such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc. For instance, when a parameter is described as an integer selected from "2~10", it is equivalent to listing the integers 2, 3, 4, 5, 6, 7, 8, 9, and 10.

[0042] In this invention, "a combination of at least two" refers to a quantity greater than or equal to two, unless otherwise specified. For example, "any combination of one or at least two" means one or more or more items. It can be understood that when referring to "a combination of at least two," it refers to any suitable combination of multiple items, that is, a combination of "at least two" items carried out in a manner that does not conflict with and enables the implementation of this invention.

[0043] Unless otherwise specified, all embodiments and optional embodiments of the present invention can be combined with each other to form new technical solutions.

[0044] The term "embodiment" as used in this invention means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment or implementation of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this invention can be combined with other embodiments.

[0045] In this invention, open-ended technical features or solutions described using terms such as "comprising" do not exclude additional members beyond those listed unless otherwise specified. They can be considered as providing both closed-ended features or solutions comprised of the listed members and open-ended features or solutions that include additional members beyond the listed members. For example, A includes a1, a2, and a3. Unless otherwise specified, it may also include other members or exclude additional members. This can be considered as providing both technical features or solutions where "A is composed of a1, a2, and a3" or "A is selected from a1, a2, and a3," and technical features or solutions where "A includes not only a1, a2, and a3, but also other members."

[0046] In this invention, unless otherwise specified, the features or solutions corresponding to "and / or" include any one of two or more of the related listed items, as well as any and all combinations of the related listed items. These arbitrary and all combinations include any two related listed items, any more related listed items, or a combination of all related listed items. For example, "A and / or B" represents a group consisting of A, B, and "a combination of A and B". "Containing A and / or B" can mean "containing A, containing B, and containing A and B", or "containing A, containing B, or containing A and B", and can be appropriately understood according to the context.

[0047] In this invention, the terms "first aspect," "second aspect," "third aspect," "fourth aspect," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or quantity, nor should they be construed as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first," "second," "third," "fourth," etc., serve only as a non-exhaustive enumeration and should be understood not to constitute a closed limitation on the quantity.

[0048] In this invention, "optional" means that something is optional, that is, it refers to either "with" or "without". If there are multiple "optional" options in a technical solution, unless otherwise specified, and there are no contradictions or mutual constraints, then each "optional" option is independent.

[0049] In this invention, "room temperature" generally refers to 4℃~35℃, and can refer to 20℃±5℃. In some embodiments of this invention, room temperature refers to 20℃~30℃.

[0050] One embodiment of the present invention provides a method for recycling valuable metals from waste ternary lithium battery cathode materials, the recycling method comprising the following steps:

[0051] (1) The black powder of the cathode material of the waste ternary lithium battery is reduced and leached to obtain a leaching slurry. The leaching slurry is then treated to remove impurities to obtain a ternary leachate.

[0052] (2) Extract the ternary leachate from step (1) to remove calcium and copper, and obtain an organic phase loaded with calcium and copper and a raffinate after calcium and copper removal.

[0053] (3) The raffinate after calcium and copper extraction in step (2) is subjected to resin defluorination and phosphorus treatment to obtain a solution after defluorination and phosphorus treatment;

[0054] (4) Perform nickel-cobalt-manganese co-extraction treatment on the solution after removing fluoride and phosphorus in step (3) to obtain a mixed solution containing nickel, cobalt and manganese and a lithium-containing solution.

[0055] This invention employs a specific process and sequence of steps, including reduction leaching, impurity removal, extraction to remove calcium and copper, resin defluorination, and phosphorus-nickel-cobalt-manganese co-extraction, rather than the single "impurity removal-extraction" or "extraction-impurity removal" modes commonly used in existing technologies. This effectively avoids the interference of calcium on subsequent extraction processes, resulting in high recovery rates of valuable metals and thorough separation of impurities. The resulting battery-grade nickel-cobalt-manganese mixed solution can be directly used to prepare ternary precursors. Furthermore, it achieves the recovery of lithium, a valuable metal. The recovery method is simple, efficient, and has minimal environmental pollution.

[0056] This invention, through reduction acid leaching, reduces the black powder of waste ternary lithium battery cathode material from insoluble metal oxides to low-valence metal ions (such as lithium, nickel, cobalt, manganese, and other impurity ions). Further impurity removal effectively removes impurities such as iron and aluminum, resulting in a filter residue containing graphite, iron, aluminum, and calcium, achieving initial impurity removal. Then, extraction to remove calcium and copper prevents calcium and copper ions from forming insoluble precipitates with phosphorus and fluoride ions during subsequent resin impurity removal, thus clogging resin pores and extending resin lifespan by over 30%. Next, resin removal of phosphorus and fluoride effectively reduces the concentration of phosphorus and fluoride ions in the feed solution, preventing them from forming stable complexes with the extractant during subsequent co-extraction, increasing the nickel-cobalt-manganese extraction rate by over 5%. Finally, nickel-cobalt-manganese co-extraction ensures the concentration of impurity ions in the feed solution is minimized, improving the purity of nickel, cobalt, and manganese in the back-extraction solution and recovering a lithium-containing solution. This also completes the extraction of lithium ions, a valuable metal, meeting the requirements for battery-grade products.

[0057] If the order of steps is changed, for example, performing resin dephosphorization and fluoride removal before calcium and copper extraction, calcium ions will form precipitates with phosphorus and fluoride ions in the resin column, clogging the resin pores and shortening the resin's lifespan by more than 50%. If nickel-cobalt-manganese co-extraction is performed before impurity removal, impurity ions will enter the organic phase, contaminating the extractant and reducing the number of times the extractant can be recycled. Severe third phase formation in the extraction section will block the pipes, rendering the extraction tank inoperable. If phosphorus and fluoride are not removed from the feed solution before nickel-cobalt-manganese co-extraction, fluoride and phosphate precipitates will form, creating a third phase and causing a series of problems.

[0058] Decreased extraction efficiency: The third phase precipitate accumulates at the interface between the two phases, forming a physical barrier, reducing the mass transfer area, slowing down the migration rate of nickel, cobalt and manganese ions, and reducing the extraction efficiency by 10%-20%; at the same time, the precipitate adsorbs the extractant, reducing the effective concentration of the organic phase, and the nickel extraction rate may drop from 97% to below 90%.

[0059] Equipment operation is hindered: Scale deposits adhere to the agitator, guide plate, etc., increasing agitation energy consumption; in severe cases, they block the overflow weir, destroying the phase separation effect, leading to reduced production line load or even shutdown for cleaning.

[0060] Subsequent processes are affected: the precipitate enters the back-extraction section along with the organic phase, causing excessive concentrations of fluorine and phosphorus in the back-extraction solution, affecting product purity; simultaneously, it contaminates the back-extraction solution, increasing the load on subsequent impurity removal, and also leading to increased residual impurities in the organic phase, reducing its recyclability. Therefore, in the recovery method of this application, the preparation methods and sequence must be coordinated to achieve the recovery of battery-grade nickel-cobalt-manganese solution.

[0061] In some embodiments, the reductive leaching in step (1) includes:

[0062] The waste ternary lithium battery cathode material black powder, acid solution and reducing agent are mixed and leached to obtain leaching slurry.

[0063] It is understood that the specific types of reducing agents used in the embodiments of the present invention are not unique. Without violating the overall technical concept of the present invention, the present invention applies to all conventional types of reducing agents that can perform a reducing effect; for example, the reducing agents include, but are not limited to, hydrogen peroxide and / or sodium metabisulfite.

[0064] In some embodiments, in step (1), the pH value of the mixed solution is 1 to 1.5, for example, 1, 1.1, 1.2, 1.3, 1.4 or 1.5.

[0065] In some embodiments, in step (1), the acid solution includes a sulfuric acid solution with a concentration of 1 mol / L to 5 mol / L, such as 1 mol / L, 1.5 mol / L, 2 mol / L, 2.5 mol / L, 3 mol / L, 3.5 mol / L, 4 mol / L, 4.5 mol / L, or 5 mol / L.

[0066] In some embodiments, in step (1), the temperature of the reduction leaching is 70°C to 80°C, for example, 70°C, 75°C or 80°C.

[0067] In the reduction leaching process of step (1) of the present invention, apart from the above-mentioned feature limitations, the amount of acid solution, the amount of reducing agent, etc. are all conventional technical solutions, and those skilled in the art can make adaptive selections and adjustments according to actual needs.

[0068] For example, but not limitingly, the liquid-to-solid ratio of the black powder and the acid solution is 1L / 100kg to 10L / 100kg, such as 1L / 100kg, 1.5L / 100kg, 2L / 100kg, 2.5L / 100kg, 3L / 100kg, 3.5L / 100kg, 4L / 100kg, 4.5L / 100kg, 5L / 100kg, 5.5L / 100kg, 6L / 100kg, 6.5L / 100kg, 7L / 100kg, 7.5L / 100kg, 8L / 100kg, 8.5L / 100kg, 9L / 100kg, 9.5L / 100kg, or 10L / 100kg, etc.

[0069] For example, but not limitingly, the reducing agent is added at a mass of 12% to 20% of the black powder, such as 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, or 20%.

[0070] In some embodiments, the method for removing impurities in step (1) includes alkaline leaching for impurity removal.

[0071] This invention uses alkaline leaching to neutralize and remove impurities, which can reduce the content of impurities such as iron and aluminum in the system and filter out waste residue containing elements such as graphite, iron, aluminum, and calcium, thus achieving preliminary impurity removal.

[0072] In some embodiments, the mass concentration of the alkaline solution in the alkaline leaching for impurity removal is 20% to 25%, such as 20%, 21%, 22%, 23%, 24%, or 25%.

[0073] In some embodiments, the alkaline solution includes a calcium hydroxide solution.

[0074] In some embodiments, the pH value of the alkaline leaching for impurity removal is 4.5 to 5, such as 4.5, 4.6, 4.7, 4.8, 4.9 or 5.

[0075] In some embodiments, the total concentration of nickel, cobalt and manganese metal ions in the ternary leachate of step (1) is 60 g / L to 80 g / L, for example 60 g / L, 63 g / L, 65 g / L, 68 g / L, 70 g / L, 73 g / L, 75 g / L, 78 g / L or 80 g / L.

[0076] In some embodiments, the extractant used in step (2) for removing calcium from copper includes a calcium extractant, wherein the dilution rate of the calcium extractant is 11% to 13%, for example 11%, 12% or 13%, and the saponification value of the calcium extractant is 0.01 mol / L to 0.05 mol / L, for example 0.01 mol / L, 0.02 mol / L, 0.03 mol / L, 0.04 mol / L or 0.05 mol / L.

[0077] It should be noted that the calcium extraction agent used in this invention is not the existing P204 model, but the Deyuan calcium extraction agent produced by Deyuan Factory, which can be purchased directly through commercial channels.

[0078] In some embodiments, the ratio of the O / A phase for extracting calcium-removed copper in step (2) is (1~1.2):1, for example 1:1, 1.1:1 or 1.2:1, etc.

[0079] In step (2) of this invention, during the calcium removal process, a calcium extraction agent with a specific parameter range and O / A ratio provided by this invention is selected to remove calcium. 2+ With Mn 2+ The separation coefficient is significantly higher, and the metal selectivity is outstanding. By adjusting the parameters of calcium removal and copper extraction, the calcium removal rate can reach over 99%, and the target metal Mn is basically undamaged, resulting in significant calcium removal and purification effects. However, when using P204 for calcium extraction, other impurity ions are extracted simultaneously, leading to a higher Mn loss rate, making it impossible to balance calcium removal efficiency and target metal retention.

[0080] In some embodiments, the pH value of the raffinate after calcium and copper extraction in step (2) is 3 to 3.5, for example, 3, 3.1, 3.2, 3.3, 3.4 or 3.5.

[0081] In some embodiments, the resin in step (3) comprises a resin containing aminophosphonic acid groups.

[0082] This invention uses a resin containing aminophosphonic acid groups for the removal of fluoride and phosphorus. Compared with conventional defluorination resins (such as anion exchange resins), it can not only effectively remove fluoride ions, but also remove phosphorus ions at the same time, achieving one-step impurity removal; the phosphorus removal rate can reach more than 99.5%, and the fluoride removal rate can reach more than 99%.

[0083] Specifically, the resin in step (3) of the present invention can be selected from HP3500 chelating resin.

[0084] In some embodiments, during the defluorination and phosphorus removal process in step (3), the height to diameter ratio of the resin adsorption column is (10~15):1, for example, 10:1, 11:1, 12:1, 13:1, 14:1 or 15:1, etc.

[0085] This invention uses resin columns with a relatively large aspect ratio for the removal of fluorine and phosphorus, especially resin columns with a ratio of (10~15):1, which further increases the contact time between the resin and the feed solution.

[0086] In some embodiments, during the defluorination and phosphorus treatment process in step (3), the flow rate of the feed liquid is 1BV / h to 2BV / h, for example, 1BV / h, 1.5BV / h or 2BV / h.

[0087] It is understood that the present invention can use a new, completely unused resin column for fluoride and phosphorus removal, or it can use an old resin column, which can be washed with water to remove impurities before use. The water flow rate during the washing process can be 1 BV / h to 2 BV / h.

[0088] In some embodiments, after the defluorination and phosphorus treatment in step (3) is completed, a resin regeneration treatment is performed. The resin regenerator includes a hydrochloric acid solution with a mass fraction of 5% to 8%, such as 5%, 6%, 7% or 8%.

[0089] This invention uses a relatively low concentration of hydrochloric acid solution (5%~8%) for resin regeneration, which reduces the concentration of the regenerator and reduces the consumption of the regenerator.

[0090] In some embodiments, the extractant used in step (4) for co-extraction includes HBL116 extractant.

[0091] In some embodiments, during the extraction process described in step (4), the ratio of O phase to A phase is (5~10):1, for example, 5:1, 6:1, 7:1, 8:1, 9:1 or 10:1.

[0092] In step (4) of this invention, HBL116 extractant is selected for co-extraction of nickel, cobalt and manganese. There is no need to adjust the pH value of the solution after defluorination and phosphorus removal. Extraction can be performed under the original pH value of the feed solution. There is no need to add acid or alkali to adjust the pH value, which simplifies the process steps and reduces the acid and alkali consumption cost by about 30%. After extraction, the pH of the aqueous phase equilibrium can be stably maintained at 3-4, which will not cause manganese oxidation to produce a third phase and affect the operation of the extraction tank.

[0093] It is understood that after the co-extraction process in step (4) of the present invention, an organic phase containing nickel, cobalt, and manganese and a lithium-containing raffinate are obtained. The raffinate is then directly subjected to back-extraction to obtain a nickel, cobalt, and manganese solution.

[0094] In some embodiments, the stripping agent in the back-extraction treatment after co-extraction includes a sulfuric acid solution with a concentration of 0.1 mol / L to 1.5 mol / L, such as 0.1 mol / L, 0.3 mol / L, 0.5 mol / L, 0.8 mol / L, 1 mol / L, 1.2 mol / L, 1.3 mol / L, or 1.5 mol / L.

[0095] Furthermore, this invention uses an extraction condition with an O phase (organic phase) / A phase (aqueous phase) ratio of (5~10):1 for co-extraction treatment, further controlling the extraction equilibrium pH to be within 3.5~4.0, so that there is no third phase in the extraction section, thus improving the co-extraction effect.

[0096] It should be noted that the specific processing method for obtaining black powder of cathode material from waste ternary lithium batteries is not unique, and this invention does not impose any specific limitations. Any conventional technical solution is applicable to this invention without violating the overall technical concept.

[0097] Example, but not limitation, of the present invention provides a method for obtaining black powder of cathode material from waste ternary lithium batteries, comprising:

[0098] Waste ternary lithium batteries are disassembled into individual battery cells, and after discharge, crushing, and sorting, black powder, the positive electrode material of waste ternary lithium batteries, is obtained.

[0099] The numerical range described in this invention includes not only the point values ​​listed above, but also any point values ​​within the numerical ranges not listed above. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific point values ​​included in the range.

[0100] The ternary cathode materials used in the following examples and comparative examples all have the chemical formula Ni. 0.6 Co 0.2 Mn 0.2 O2 (NCM622) material.

[0101] Example 1

[0102] This embodiment provides a method for recycling valuable metals from waste ternary lithium battery cathode materials, such as... Figure 1 As shown, the recycling method includes the following steps:

[0103] (1) Full leaching: Mix 100kg of ternary black powder with 700L of sulfuric acid solution with a concentration of 2mol / L, add 15kg of sodium metabisulfite, and the pH value of the resulting mixed solution is 1. Stir and leach at 70℃ for 3 hours to obtain leaching slurry.

[0104] The leachate was slowly added to a 20% calcium hydroxide solution to adjust the pH to 4.5. After stirring for 1 hour, the mixture was filtered to obtain a ternary leachate with a main content (Co+Ni+Mn) of 50 g / L. The iron and aluminum content was reduced to 0.1 mg / L. The filter residue was a waste residue containing graphite, iron, aluminum, calcium and other elements, thus achieving preliminary impurity removal.

[0105] (2) Extraction to remove calcium: The filtered ternary leachate was extracted with calcium extraction extractant (Deyuan calcium extraction extractant, dilution rate 12%, saponification value 0.03mol / L) to remove calcium and copper. The ratio of O phase to A phase was 1:1. After extraction, the organic phase loaded with calcium and copper and the raffinate after calcium and copper extraction were obtained. The pH of the raffinate was 3.3.

[0106] (3) Resin removal of phosphorus and fluoride: 100 mL of HP3500 chelating resin was packed into an adsorption column with a height-to-diameter ratio of 10:1; the adsorption column was rinsed with water at a flow rate of 2 BV / h until the effluent was clear; then the raffinate after calcium and copper extraction was passed through the pretreated resin bed at a flow rate of 2 BV / h, and the concentration of metal ions in the effluent was measured every 2 hours for a total of 12 times until the resin was saturated, and the solution after fluoride and phosphorus removal was obtained; the adsorption column was regenerated by acid washing with a hydrochloric acid solution with a mass concentration of 8%, and the resin could be recycled;

[0107] (4) Nickel-cobalt-manganese co-extraction: The solution after removing fluorine and phosphorus was co-extracted using HBL116 extractant with an O phase / A phase ratio of 8:1, resulting in an organic phase containing nickel, cobalt, and manganese and a lithium-containing raffinate. The organic phase containing nickel, cobalt, and manganese was back-extracted using a 1 mol / L sulfuric acid solution. The nickel-cobalt-manganese solution (nickel-cobalt-manganese sulfate solution) obtained after back-extraction can be directly used to prepare ternary precursors. The lithium-containing raffinate can be treated to precipitate lithium carbonates and recover lithium-containing compounds.

[0108] Example 2

[0109] This embodiment provides a method for recycling valuable metals from waste ternary lithium battery cathode materials. The recycling method includes the following steps:

[0110] (1) Full leaching: Mix 100 kg of ternary black powder with 700 L of sulfuric acid solution with a concentration of 5 mol / L, add 15 kg of sodium metabisulfite, and the pH value of the resulting mixed solution is 1.5. Stir and leach at 80℃ for 2.5 hours to obtain leaching slurry;

[0111] The leachate was slowly added to a 25% calcium hydroxide solution to adjust the pH to 5. After stirring for 1.5 hours, it was filtered to obtain a ternary leachate (nickel-cobalt-manganese-lithium solution) with a main content (Co+Ni+Mn) of 50 g / L. The iron and aluminum content was reduced to 0.1 mg / L. The filter residue was a waste residue containing graphite, iron, aluminum, calcium and other elements, achieving preliminary impurity removal.

[0112] (2) Extraction to remove calcium: The filtered ternary leachate was extracted with calcium extraction extractant (Deyuan calcium extraction extractant, dilution rate 12%, saponification value 0.03mol / L) to remove calcium. The ratio of O phase to A phase was 1:1.2. After extraction, the organic phase loaded with calcium and copper and the raffinate after calcium and copper extraction were obtained. The pH of the raffinate was 3.

[0113] (3) Resin removal of phosphorus and fluoride: 100 mL of HP3500 chelating resin was packed into an adsorption column with a height-to-diameter ratio of 15:1; the adsorption column was rinsed with water at a flow rate of 2 BV / h until the effluent was clear; then the raffinate after calcium and copper extraction was passed through the pretreated resin bed at a flow rate of 1 BV / h, and the concentration of metal ions in the effluent was measured every 2 hours for a total of 12 times until the resin adsorption was saturated, and the solution after fluoride and phosphorus removal was obtained; the adsorption column was acid washed and regenerated with a hydrochloric acid solution with a mass concentration of 8%, and the resin could be recycled;

[0114] (4) Nickel-cobalt-manganese co-extraction: The solution after removing fluorine and phosphorus was co-extracted with HBL116 extractant. The ratio of O phase to A phase was 5:1, resulting in an organic phase containing nickel, cobalt, and manganese and a lithium-containing raffinate. The organic phase containing nickel, cobalt, and manganese was back-extracted with a 1 mol / L sulfuric acid solution. The nickel-cobalt-manganese solution obtained after back-extraction can be directly used to prepare ternary precursors. The lithium-containing raffinate can be treated to precipitate lithium carbonates and recover lithium-containing compounds.

[0115] Example 3

[0116] The difference between this embodiment and embodiment 1 is that in step (2) of this embodiment, the ratio of O / A phase is 0.8:1.

[0117] All other conditions remain the same as in Example 1.

[0118] Example 4

[0119] The difference between this embodiment and embodiment 1 is that in step (2) of this embodiment, the ratio of O / A phase is 1.5:1.

[0120] All other conditions remain the same as in Example 1.

[0121] Example 5

[0122] The difference between this embodiment and embodiment 1 is that the resin in step (3) of this embodiment is zirconium resin SpheliteACD-17C.

[0123] All other conditions remain the same as in Example 1.

[0124] Example 6

[0125] The difference between this embodiment and embodiment 1 is that in step (3) of this embodiment, during the adsorption process, the residual liquid after calcium extraction passes through the pretreated resin bed at a flow rate of 3 BV / h.

[0126] All other conditions remain the same as in Example 1.

[0127] Example 7

[0128] The difference between this embodiment and embodiment 1 is that in the co-extraction process of step (4) in this embodiment, the ratio of O phase to A phase is 4:1.

[0129] All other conditions remain the same as in Example 1.

[0130] Comparative Example 1

[0131] The difference between this comparative example and Example 1 is that this comparative example does not perform the impurity removal step (1), but directly filters the leachate to obtain a ternary leachate.

[0132] All other conditions remain the same as in Example 1.

[0133] Comparative Example 2

[0134] The difference between this comparative example and Example 1 is that this comparative example does not perform step (2).

[0135] All other conditions remain the same as in Example 1.

[0136] Comparative Example 3

[0137] The difference between this comparative example and Example 1 is that this comparative example does not perform step (3).

[0138] All other conditions remain the same as in Example 1.

[0139] Comparative Example 4

[0140] The difference between this comparative example and Example 1 is that the order of steps (2) and (3) is reversed in this comparative example.

[0141] All other conditions remain the same as in Example 1.

[0142] Comparative Example 5

[0143] The difference between this comparative example and Example 1 is that in this comparative example, the ternary leachate in step (1) is first subjected to step (4), and then steps (2) and (3) are performed sequentially.

[0144] All other conditions remain the same as in Example 1.

[0145] The total mass concentration of nickel, cobalt, and manganese, as well as the calcium ion content, fluorine content, and phosphorus content in the solutions obtained from the above examples and comparative examples were tested. The test results are shown in Table 1.

[0146] Table 1

[0147]

[0148] From Table 1, we can obtain:

[0149] The present invention provides a method for recovering valuable metals from waste ternary lithium battery cathode materials. This method effectively avoids the interference of calcium in the subsequent extraction process, achieves a high recovery rate of valuable metals, and thoroughly separates impurities. It yields a battery-grade nickel-cobalt-manganese mixed solution that can be directly used to prepare ternary precursors. Furthermore, it also realizes the recovery of lithium, a valuable metal. The recovery method is simple, efficient, and has a low degree of environmental pollution.

[0150] Data analysis of Examples 1, 3, and 4 shows that during the extraction of calcium-removing copper, the ratio of the O phase to the A phase in the extraction process directly affects the calcium removal depth and the Mn loss rate. In Example 3, the ratio is too small, resulting in insufficient Ca removal depth and excessive Ca in the solution, which affects the purity of the product in the subsequent nickel-cobalt-manganese co-extraction process. In Example 4, the ratio is too large, resulting in deeper Ca removal depth, but manganese will be lost, and alkali consumption will increase.

[0151] Data analysis of Examples 1 and 5 shows that HP3500 chelating resin is used for defluorination and phosphorus removal, which can achieve deep and efficient removal of fluorine and phosphorus impurities, while ensuring a high recovery rate of valuable metals, providing high-quality feed solution for subsequent nickel-cobalt-manganese co-extraction process, and finally obtaining a high-purity nickel-cobalt-manganese mixed solution.

[0152] Data analysis of Examples 1 and 6 shows that the flow rate of the feed solution is relatively low during resin defluorination and phosphorus removal, especially 1 BV / h to 2 BV / h. This flow rate range can ensure the deep removal of fluoride and phosphorus ions, make full use of the resin adsorption capacity, enhance process stability, provide high-quality feed solution for the subsequent nickel-cobalt-manganese co-extraction process, and finally obtain a high-purity nickel-cobalt-manganese mixed solution.

[0153] Data analysis of Examples 1 and 7 shows that, during nickel-cobalt-manganese co-extraction, the ratio of O phase to A phase during extraction is (5~10):1, ensuring a high co-extraction rate (≥99.5%) and a low impurity entrainment rate for nickel, cobalt, and manganese. This technology not only solves the long-standing problem of the third phase in the industry but also reduces alkali consumption costs by approximately 30%.

[0154] Data analysis of Example 1 and Comparative Examples 1-5 shows that in the recycling method provided by the present invention, each preparation step and its preparation sequence must be coordinated and indispensable in order to achieve effective co-extraction of nickel, cobalt and manganese and improve the recovery effect of valuable metals.

[0155] The above description is only a specific embodiment 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 conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A method for recycling valuable metals from waste ternary lithium battery cathode materials, characterized in that, The recycling method includes the following steps: (1) The black powder of the cathode material of the waste ternary lithium battery is reduced and leached to obtain a leaching slurry. The leaching slurry is then treated to remove impurities to obtain a ternary leachate. (2) Extract the ternary leachate from step (1) to remove calcium and copper, and obtain an organic phase loaded with calcium and copper and a raffinate after calcium and copper removal. (3) The raffinate after calcium and copper extraction in step (2) is subjected to resin defluorination and phosphorus treatment to obtain a solution after defluorination and phosphorus treatment; (4) Perform nickel-cobalt-manganese co-extraction treatment on the solution after removing fluoride and phosphorus in step (3) to obtain a mixed solution containing nickel, cobalt and manganese and a lithium-containing solution.

2. The recycling method according to claim 1, characterized in that, The reduction leaching in step (1) includes: The waste ternary lithium battery cathode material black powder, acid solution and reducing agent are mixed and leached to obtain leaching slurry.

3. The recycling method according to claim 2, characterized in that, In step (1), the pH value of the mixed solution is 1~1.5; Preferably, in step (1), the acid solution includes a sulfuric acid solution, and the concentration of the sulfuric acid solution is 1 mol / L to 5 mol / L; Preferably, in step (1), the temperature of the reduction leaching is 70℃~80℃.

4. The recycling method according to claim 1 or 2, characterized in that, The method for removing impurities in step (1) includes alkaline leaching.

5. The recycling method according to claim 4, characterized in that, The mass concentration of the alkaline solution used in the alkaline leaching for impurity removal is 20%~25%; Preferably, the pH value of the alkaline leaching for impurity removal is 4.5~5; Preferably, the total concentration of nickel, cobalt and manganese metal ions in the ternary leachate in step (1) is 60 g / L to 80 g / L.

6. The recycling method according to claim 1, characterized in that, The extractant used in step (2) for removing calcium from copper includes a calcium extraction extractant, the dilution rate of which is 11% to 13%, and the saponification value of which is 0.01 mol / L to 0.05 mol / L; Preferably, the ratio of the O / A phase for extracting calcium and copper in step (2) is (1~1.2):

1.

7. The recycling method according to claim 1 or 6, characterized in that, The pH value of the raffinate after calcium and copper extraction in step (2) is 3~3.

5.

8. The recycling method according to claim 1, characterized in that, The resin in step (3) includes a resin containing aminophosphonic acid groups.

9. The recycling method according to claim 1 or 8, characterized in that, In step (3), during the defluorination and phosphorus removal process, the height to diameter ratio of the resin adsorption column used is (10~15):

1. Preferably, in the defluorination and phosphorus treatment process described in step (3), the flow rate of the feed liquid is 1 BV / h to 2 BV / h; Preferably, after the fluoride and phosphorus removal treatment in step (3) is completed, a resin regeneration treatment is performed, wherein the resin regenerator includes a hydrochloric acid solution with a mass fraction of 5% to 8%.

10. The recycling method according to claim 1, characterized in that, The extractant used in step (4) for co-extraction includes HBL116 extractant; Preferably, in the extraction process described in step (4), the ratio of O phase to A phase is (5~10):1.

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