Method for preparing finely filtered nickel-cobalt-manganese metal liquid by utilizing ternary precursor mother liquor

Abstract

The invention relates to the field of production and manufacturing of lithium battery positive electrode material precursors, in particular to a method for preparing refined filtration nickel-cobalt-manganese metal liquid by utilizing ternary precursor mother liquor, which comprises the following steps: step 1, adding a first pH regulator into the ternary precursor mother liquor; 2, carrying out ammonia removal treatment on the ternary precursor mother liquor; step 3, adding a coagulant into the ternary precursor mother liquor; step 4, separating out precipitates in the ternary precursor mother liquor; 5, mixing the precipitate with pure water to obtain a pulpified material; step 6, adding an acid solution into the pulpified material; step 7, adding an oxidizing agent into the pulpified material; 8, carrying out solid-liquid separation treatment on the pulpified material to obtain a filtrate part and a filter residue part; step 9, repeatedly executing the operation in the step 5 on the filter residue part, and adding a second pH regulator into the filtrate part; and 10, the filtrate part is subjected to solid-liquid separation treatment, and refined-filtered nickel-cobalt-manganese metal liquid and waste residues are obtained.

Description

Technical Field

[0001] This invention relates to the field of lithium battery cathode material precursor production and manufacturing, specifically to a method for preparing finely filtered nickel-cobalt-manganese metal liquid using ternary precursor mother liquor. Background Technology

[0002] Nickel-cobalt-manganese ternary cathode materials, as core materials for lithium-ion batteries, have become the mainstream choice in the mid-to-high-end electric vehicle market due to their excellent cycle performance and significant cost advantages. With the booming development of the new energy vehicle industry, its market demand continues to grow rapidly, demonstrating broad development prospects.

[0003] However, existing processes for preparing nickel-cobalt-manganese ternary cathode materials still present pressing technical challenges. Among these, the insufficient utilization rate of nickel, cobalt, and manganese metals is particularly prominent. Some of these metals are carried out of the system with the mother liquor, leading not only to the risk of heavy metal contamination during mother liquor discharge but also to low recovery rates, resulting in significant resource waste. Furthermore, improper discharge of heavy metals from the mother liquor can also pose potential environmental hazards. Further investigation revealed that the mother liquor produced during the process has a complex composition, containing not only small amounts of nickel, cobalt, and manganese metals, but also iron ions, free ammonia, and other substances. The presence of these complex components significantly increases the difficulty of recovering the nickel, cobalt, and manganese metals.

[0004] Therefore, how to overcome the shortcomings of the existing technology is the subject of this invention. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing finely filtered nickel-cobalt-manganese metal liquid using ternary precursor mother liquor.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A method for preparing finely filtered nickel-cobalt-manganese metal liquid using ternary precursor mother liquor includes: Step 1: Add the first pH adjuster to the ternary precursor mother liquor; Step 2: Remove ammonia from the ternary precursor mother liquor after pH adjustment; Step 3: Add a coagulant to the mother liquor of the ternary precursor after ammonia removal treatment; Step 4: Separate the precipitate from the ternary precursor mother liquor after adding the coagulant; Step 5: Mix the precipitate with pure water to obtain a slurry; Step 6: Add an acid solution to the slurry; Step 7: Add an oxidizing agent to the slurry after adding the acid solution; Step 8: Perform solid-liquid separation treatment on the slurry after adding the oxidant to obtain a filtrate portion and a filter residue portion; Step 9: Repeat the operation in Step 5 on the filter residue portion, and add a second pH adjuster to the filtrate portion; Step 10: Perform solid-liquid separation treatment on the filtrate after adding the second pH adjuster to obtain finely filtered nickel-cobalt-manganese metal liquid and waste residue.

[0007] In step one, the first pH adjuster is one or more of sodium hydroxide or potassium hydroxide, which facilitates the subsequent ammonia removal treatment. The pH adjuster can make the pH of the ternary precursor mother liquor ≥12 (not limited to this), thereby achieving effective removal of free ammonia (which can be achieved by means of stripping).

[0008] The purpose of step two is to remove ammonia and prevent the complexation of free ammonia from affecting the formation of nickel-cobalt-manganese precipitates.

[0009] In step three, a coagulant is used to promote the precipitation of nickel, cobalt, and manganese.

[0010] In step four, the precipitate is a recovered nickel-cobalt-manganese material. After adding a coagulant, a separation operation is performed within a predetermined time period.

[0011] In step five, the precipitated particles are dispersed in pure water to increase the formation rate of the subsequent nickel-cobalt-manganese metal liquid.

[0012] In step six, acid leaching is performed using an acid solution to gradually transform the nickel-cobalt-manganese precipitate (nickel-cobalt-manganese slurry) into a nickel-cobalt-manganese molten metal, facilitating the subsequent removal of impurities such as iron ions.

[0013] In step seven, ferrous ions are oxidized to ferric ions using an oxidizing agent.

[0014] In step eight, since the acid leaching treatment in step six is ​​difficult to achieve a leaching rate of 100%, the filter residue is mainly composed of nickel, cobalt, and manganese precipitates. Solid-liquid separation can be achieved by pressure filtration.

[0015] In step nine, considering the composition of the filter residue, the operation in step five is repeated to increase the total recovery of the finely filtered nickel-cobalt-manganese metal liquid. The composition of the second pH adjuster can be the same as that of the first pH adjuster. The addition of the second pH adjuster causes ferric ions to form ferric hydroxide precipitate, and aluminum ions to form aluminum hydroxide precipitate when present.

[0016] In step ten, a finely filtered nickel-cobalt-manganese molten metal is obtained, which is used as a raw material for the production of ternary precursors. Waste residue (including at least ferric hydroxide precipitate) is also obtained, which is recycled to improve resource utilization. Solid-liquid separation can be achieved through filtration. When the filtration pressure reaches a certain limit, the filtration equipment is backwashed, and the backwash water can be used as a slurry.

[0017] This application utilizes a finely filtered nickel-cobalt-manganese metal liquid obtained from the mother liquor of a ternary precursor, thereby improving the recovery rate of nickel, cobalt, and manganese metals, preventing the waste of precious metal resources, and avoiding environmental pollution from the mother liquor due to excessive heavy metals. This achieves the simultaneous development of resource conservation and environmental protection. Furthermore, the recovered nickel-cobalt-manganese metal liquid is a finely filtered solution, removing impurities such as iron ions, reducing the difficulty of subsequent utilization of nickel, cobalt, and manganese, such as direct use in the production of ternary precursor products.

[0018] The main impurity removal targets of this application are free ammonia and ferrous ions, which have a significant impact and are present in large quantities. Other steps may also be introduced to remove other possible impurities. Some examples of impurity removal methods are as follows: For water-insoluble substances, they can be filtered by plate and frame filtration, centrifugal filtration, or membrane filtration (such as microfiltration membranes); For sodium ions, existing methods are used, such as using cation exchange resins (e.g., sodium-type ion exchange resins), to remove sodium ions through an exchange reaction.

[0019] In some embodiments, in step nine, the pH of the filtrate is adjusted to 4-5 to ensure the formation of ferric hydroxide precipitate.

[0020] In a further technical solution, step four, the step of separating the precipitate, includes: S1. Perform solid-liquid separation treatment on the ternary precursor mother liquor after adding the coagulant to obtain a solid part and a liquid part; S2. The liquid portion is filtered to obtain slag material; S3. The solid portion and the slag discharge material are subjected to pressure filtration to obtain the precipitate.

[0021] In S1, existing solid-liquid separators can be used to carry out solid-liquid separation treatment.

[0022] By combining solid-liquid separation and filtration, the recovery rate of precipitates is increased, thereby improving the recovery rate of nickel, cobalt, and manganese metals. Furthermore, by using pressure filtration, the water content of the precipitates is reduced, thus increasing the purity of the precipitates.

[0023] In a further technical solution, both the first pH adjuster and the second pH adjuster include at least one of sodium hydroxide and potassium hydroxide.

[0024] By using the design of this application, it is possible to avoid introducing impurities that are difficult to remove, thereby avoiding increasing the difficulty of obtaining finely filtered nickel-cobalt-manganese molten metal.

[0025] In a further technical solution, the coagulant is set as either an aluminum salt coagulant or an iron salt coagulant.

[0026] The purpose of this application is also to avoid introducing impurities that are difficult to remove, thereby avoiding increasing the difficulty of obtaining finely filtered nickel-cobalt-manganese molten metal.

[0027] In a further technical solution, the solid-liquid ratio of the precipitate to the pure water is in the range of 0.38-0.5; The mixing time between the precipitate and the pure water is ≥30 min.

[0028] By implementing the settings of this application, the precipitate is fully pulped, reducing the total amount of filter residue in step eight and increasing the single-cycle recovery of finely filtered nickel-cobalt-manganese metal liquid.

[0029] In a further technical solution, the acid solution is set as any one of sulfuric acid solution, nitric acid solution and hydrochloric acid solution; The concentration range of the acid solution is 7 mol / L-8 mol / L; The solid-liquid ratio of the precipitate to the acid solution is in the range of 0.5-0.7.

[0030] The concentration range of the acid solution is 7 mol / L-8 mol / L to ensure the concentration of the leachate. At the same time, by setting the solid-liquid ratio of the precipitate to the acid solution to a range of 0.5-0.7, the leaching rate is improved, the total amount of filter residue in step eight is further reduced, and the single recovery amount of the finely filtered nickel-cobalt-manganese metal liquid is increased.

[0031] In this application, the reaction time can be set to 2-2.5 hours.

[0032] In a further technical solution, the oxidant is set as one or more of hydrogen peroxide solution, sodium peroxide solution and potassium peroxide solution; The concentration range of the oxidant is 8 mol / L-9 mol / L; The solid-liquid ratio of the precipitate to the oxidant is in the range of 2-2.5.

[0033] In some embodiments, considering both reaction rate and equipment operational stability, this application is implemented in an environment with a reaction temperature of 60°C-80°C.

[0034] By setting the solid-liquid ratio of the precipitate to the oxidant to a range of 2-2.5, complete oxidation of ferrous ions can be ensured.

[0035] In this application, the reaction time can be set to 3.5-4 hours.

[0036] The terms "first," "second," etc., used in this article do not specifically refer to order or sequence, nor are they intended to limit this case; they are merely used to distinguish components or operations described using the same technical terms.

[0037] The terms "connection" or "positioning" as used in this article can refer to two or more components or devices making direct physical contact with each other, or making indirect physical contact with each other, or to two or more components or devices operating or moving with each other.

[0038] The terms “include,” “including,” and “have” used in this article are all open-ended, meaning they include but are not limited to.

[0039] Unless otherwise specified, the terms used herein generally have their ordinary meaning in the context of the art, the subject matter, and the specific context. Certain terms used to describe this case will be discussed below or elsewhere in this specification to provide additional guidance to those skilled in the art in describing the case.

[0040] The terms “front,” “back,” “up,” “down,” “left,” and “right” used in this article are directional terms. In this case, they are only used to describe the positional relationship between the structures and are not intended to limit the specific direction of the protection scheme or its actual implementation.

[0041] The working principle and advantages of this invention are as follows: This application utilizes a finely filtered nickel-cobalt-manganese metal liquid obtained from the mother liquor of a ternary precursor, thereby improving the recovery rate of nickel, cobalt, and manganese metals, preventing the waste of precious metal resources, and avoiding environmental pollution from the mother liquor due to excessive heavy metals. This achieves the simultaneous development of resource conservation and environmental protection. Furthermore, the recovered nickel-cobalt-manganese metal liquid is a finely filtered solution, removing impurities such as iron ions, reducing the difficulty of subsequent utilization of nickel, cobalt, and manganese, such as direct use in the production of ternary precursor products. Attached Figure Description

[0042] Figure 1 This is a flowchart of a method for preparing finely filtered nickel-cobalt-manganese metal liquid using a ternary precursor mother liquor, as described in an embodiment of the present invention. Detailed Implementation

[0043] The present invention will be further described below with reference to the accompanying drawings and embodiments: Example: The present invention will be clearly described below with illustrations and detailed description. Any person skilled in the art who understands the examples of the present invention can make changes and modifications based on the technology taught in the present invention without departing from the spirit and scope of the present invention.

[0044] The terminology used herein is for the purpose of describing specific embodiments only and is not intended to limit the scope of this work. Singular forms such as “a,” “this,” “this,” “the,” and “the” as used herein also include plural forms.

[0045] See Figure 1 A method for preparing finely filtered nickel-cobalt-manganese metal liquid using ternary precursor mother liquor, comprising: Step 1: Add the first pH adjuster to the ternary precursor mother liquor; Step 2: Remove ammonia from the ternary precursor mother liquor after pH adjustment; Step 3: Add a coagulant to the mother liquor of the ternary precursor after ammonia removal treatment; Step 4: Separate the precipitate from the ternary precursor mother liquor after adding the coagulant; Step 5: Mix the precipitate with pure water to obtain a slurry; Step 6: Add an acid solution to the slurry; Step 7: Add an oxidizing agent to the slurry after adding the acid solution; Step 8: Perform solid-liquid separation treatment on the slurry after adding the oxidant to obtain a filtrate portion and a filter residue portion; Step 9: Repeat the operation in Step 5 on the filter residue portion, and add a second pH adjuster to the filtrate portion; Step 10: Perform solid-liquid separation treatment on the filtrate after adding the second pH adjuster to obtain finely filtered nickel-cobalt-manganese metal liquid and waste residue.

[0046] In step one, the first pH adjuster is one or more of sodium hydroxide or potassium hydroxide, which facilitates the subsequent ammonia removal treatment. The pH adjuster can make the pH of the ternary precursor mother liquor ≥12 (not limited to this), thereby achieving effective removal of free ammonia (which can be achieved by means of stripping).

[0047] The purpose of step two is to remove ammonia and prevent the complexation of free ammonia from affecting the formation of nickel-cobalt-manganese precipitates.

[0048] In step three, a coagulant is used to promote the precipitation of nickel, cobalt, and manganese.

[0049] In step four, the precipitate is a recovered nickel-cobalt-manganese material. After adding a coagulant, a separation operation is performed within a predetermined time period.

[0050] In step five, the precipitated particles are dispersed in pure water to increase the formation rate of the subsequent nickel-cobalt-manganese metal liquid.

[0051] In step six, acid leaching is performed using an acid solution to gradually transform the nickel-cobalt-manganese precipitate (nickel-cobalt-manganese slurry) into a nickel-cobalt-manganese molten metal, facilitating the subsequent removal of impurities such as iron ions.

[0052] In step seven, ferrous ions are oxidized to ferric ions using an oxidizing agent.

[0053] In step eight, since the acid leaching treatment in step six is ​​difficult to achieve a leaching rate of 100%, the filter residue is mainly composed of nickel, cobalt, and manganese precipitates. Solid-liquid separation can be achieved by pressure filtration.

[0054] In step nine, considering the composition of the filter residue, the operation in step five is repeated to increase the total recovery of the finely filtered nickel-cobalt-manganese metal liquid. The composition of the second pH adjuster can be the same as that of the first pH adjuster. The addition of the second pH adjuster causes ferric ions to form ferric hydroxide precipitate, and aluminum ions to form aluminum hydroxide precipitate when present.

[0055] In step ten, a finely filtered nickel-cobalt-manganese molten metal is obtained, which is used as a raw material for the production of ternary precursors. Waste residue (including at least ferric hydroxide precipitate) is also obtained, which is recycled to improve resource utilization. Solid-liquid separation can be achieved through filtration. When the filtration pressure reaches a certain limit, the filtration equipment is backwashed, and the backwash water can be used as a slurry.

[0056] This application utilizes a finely filtered nickel-cobalt-manganese metal liquid obtained from the mother liquor of a ternary precursor, thereby improving the recovery rate of nickel, cobalt, and manganese metals, preventing the waste of precious metal resources, and avoiding environmental pollution from the mother liquor due to excessive heavy metals. This achieves the simultaneous development of resource conservation and environmental protection. Furthermore, the recovered nickel-cobalt-manganese metal liquid is a finely filtered solution, removing impurities such as iron ions, reducing the difficulty of subsequent utilization of nickel, cobalt, and manganese, such as direct use in the production of ternary precursor products.

[0057] The main impurity removal targets of this application are free ammonia and ferrous ions, which have a significant impact and are present in large quantities. Other steps may also be introduced to remove other possible impurities. Some examples of impurity removal methods are as follows: For water-insoluble substances, they can be filtered by plate and frame filtration, centrifugal filtration, or membrane filtration (such as microfiltration membranes); For sodium ions, existing methods are used, such as using cation exchange resins (e.g., sodium-type ion exchange resins), to remove sodium ions through an exchange reaction.

[0058] In some embodiments, in step nine, the pH of the filtrate is adjusted to 4-5 to ensure the formation of ferric hydroxide precipitate.

[0059] In this embodiment, step four, the step of separating the precipitate, includes: S1. Perform solid-liquid separation treatment on the ternary precursor mother liquor after adding the coagulant to obtain a solid part and a liquid part; S2. The liquid portion is filtered to obtain slag material; S3. The solid portion and the slag discharge material are subjected to pressure filtration to obtain the precipitate.

[0060] In S1, existing solid-liquid separators can be used to carry out solid-liquid separation treatment.

[0061] By combining solid-liquid separation and filtration, the recovery rate of precipitates is increased, thereby improving the recovery rate of nickel, cobalt, and manganese metals. Furthermore, by using pressure filtration, the water content of the precipitates is reduced, thus increasing the purity of the precipitates.

[0062] In this embodiment, both the first pH adjuster and the second pH adjuster include at least one of sodium hydroxide and potassium hydroxide.

[0063] The configuration in this embodiment avoids introducing impurities that are difficult to remove, thereby avoiding increasing the difficulty of obtaining finely filtered nickel-cobalt-manganese molten metal.

[0064] In this embodiment, the coagulant is either an aluminum salt coagulant or an iron salt coagulant.

[0065] The purpose of this embodiment is also to avoid introducing impurities that are difficult to remove, thereby avoiding increasing the difficulty of obtaining finely filtered nickel-cobalt-manganese metal liquid.

[0066] In this embodiment, the solid-liquid ratio of the precipitate to the pure water is in the range of 0.38-0.5; The mixing time between the precipitate and the pure water is ≥30 min.

[0067] The setup in this embodiment ensures complete slurry formation of the precipitate, reduces the total amount of filter residue in step eight, and increases the single-cycle recovery of finely filtered nickel-cobalt-manganese metal liquid.

[0068] In this embodiment, the acid solution is any one of sulfuric acid solution, nitric acid solution, and hydrochloric acid solution; The concentration range of the acid solution is 7 mol / L-8 mol / L; The solid-liquid ratio of the precipitate to the acid solution is in the range of 0.5-0.7.

[0069] The concentration range of the acid solution is 7 mol / L-8 mol / L to ensure the concentration of the leachate. At the same time, by setting the solid-liquid ratio of the precipitate to the acid solution to a range of 0.5-0.7, the leaching rate is improved, the total amount of filter residue in step eight is further reduced, and the single recovery amount of the finely filtered nickel-cobalt-manganese metal liquid is increased.

[0070] In this embodiment, the reaction time can be set to 2-2.5 hours.

[0071] In this embodiment, the oxidant is one or more of hydrogen peroxide solution, sodium peroxide solution, and potassium peroxide solution; The concentration range of the oxidant is 8 mol / L-9 mol / L; The solid-liquid ratio of the precipitate to the oxidant is in the range of 2-2.5.

[0072] In some embodiments, considering both reaction rate and equipment operational stability, this embodiment is implemented in an environment with a reaction temperature of 60°C-80°C.

[0073] By setting the solid-liquid ratio of the precipitate to the oxidant to a range of 2-2.5, complete oxidation of ferrous ions can be ensured.

[0074] In this embodiment, the reaction time can be set to 3.5-4 hours.

[0075] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing finely filtered nickel-cobalt-manganese metal liquid using ternary precursor mother liquor, characterized in that: include: Step 1: Add a first pH adjuster to the ternary precursor mother liquor to make the pH of the ternary precursor mother liquor ≥ 12; Step 2: Remove ammonia from the ternary precursor mother liquor after pH adjustment; Step 3: Add a coagulant to the mother liquor of the ternary precursor after ammonia removal treatment; Step 4: Separate the precipitate from the ternary precursor mother liquor after adding the coagulant; Step 5: Mix the precipitate with pure water to obtain a slurry; Step 6: Add an acid solution to the slurry; Step 7: Add an oxidizing agent to the slurry after adding the acid solution; Step 8: Perform solid-liquid separation treatment on the slurry after adding the oxidant to obtain a filtrate portion and a filter residue portion; Step 9: Repeat the operation in Step 5 on the filter residue portion, and add a second pH adjuster to the filtrate portion to adjust the pH value of the filtrate portion to 4-5; Step 10: Perform solid-liquid separation treatment on the filtrate after adding the second pH adjuster to obtain finely filtered nickel-cobalt-manganese metal liquid and waste residue.

2. The method for preparing finely filtered nickel-cobalt-manganese metal liquid using a ternary precursor mother liquor according to claim 1, characterized in that: Step four, the step of separating the precipitate, includes: S1. Perform solid-liquid separation treatment on the ternary precursor mother liquor after adding the coagulant to obtain a solid part and a liquid part; S2. The liquid portion is filtered to obtain slag material; S3. The solid portion and the slag discharge material are subjected to pressure filtration to obtain the precipitate.

3. The method for preparing finely filtered nickel-cobalt-manganese metal liquid using a ternary precursor mother liquor according to claim 1, characterized in that: Both the first pH adjuster and the second pH adjuster include at least one of sodium hydroxide and potassium hydroxide.

4. The method for preparing finely filtered nickel-cobalt-manganese metal liquid using a ternary precursor mother liquor according to claim 1, characterized in that: The coagulant is set to either an aluminum salt coagulant or an iron salt coagulant.

5. The method for preparing finely filtered nickel-cobalt-manganese metal liquid using a ternary precursor mother liquor according to claim 1, characterized in that: The solid-liquid ratio of the precipitate to the pure water is in the range of 0.38-0.5; The mixing time between the precipitate and the pure water is ≥30 min.

6. The method for preparing finely filtered nickel-cobalt-manganese metal liquid using a ternary precursor mother liquor according to claim 1, characterized in that: The acid solution is any one of sulfuric acid solution, nitric acid solution and hydrochloric acid solution; The concentration range of the acid solution is 7 mol / L-8 mol / L; The solid-liquid ratio of the precipitate to the acid solution is in the range of 0.5-0.

7.

7. The method for preparing finely filtered nickel-cobalt-manganese metal liquid using a ternary precursor mother liquor according to claim 1, characterized in that: The oxidant is one or more selected from hydrogen peroxide solution, sodium peroxide solution and potassium peroxide solution; The concentration range of the oxidant is 8 mol / L-9 mol / L; The solid-liquid ratio of the precipitate to the oxidant is in the range of 2-2.5.

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