A one-step impurity removal method for ternary lithium battery leachate from waste power batteries

Abstract

This invention provides a one-step purification method for ternary lithium battery leachate. By introducing a portion of aluminum source and controlling the Al / F molar ratio in the solution system to ≥4, and then adding an alkaline source to adjust the pH for precipitation treatment, Fe, Al, and F can be purified by precipitation in one step without introducing other elements such as Ca and Mg. After one-step purification, the F content in the solution is less than 100 mg / L, the Fe content is less than 10 mg / L, and the Al content is less than 10 mg / L. This method has the advantages of simple operation, simple equipment, low energy consumption, and no pollution.

Description

Technical Field

[0001] This invention relates to the field of waste power battery recycling technology, specifically to a one-step impurity removal method for ternary lithium battery leachate from waste power batteries. Background Technology

[0002] As the "heart" of new energy vehicles, the use of power batteries is increasing daily. Therefore, many countries are working on low-cost, high-efficiency recycling of used power batteries in hopes of maximizing profits.

[0003] The black powder from dismantled and crushed waste power batteries is typically leached using sulfuric acid and a reducing agent. The leachate (hereinafter referred to as ternary leachate) is then adjusted for pH by introducing a calcium source to remove iron and aluminum. After iron and aluminum removal, the solution enters P204 and P508 extraction for further purification and crystallization. This full extraction process requires the addition of liquid alkali for saponification of the organic solution, resulting in high alkali consumption. Therefore, the method for removing impurities from the ternary leachate before extraction is crucial. Semi-extraction purification can reduce alkali consumption during the extraction stage.

[0004] Although the method of removing iron and aluminum by adding calcium source to adjust pH in ternary leachate can remove iron and aluminum to below 1 ppm, the large amount of calcium introduced will cause calcium slag to form and block the pipeline during the subsequent extraction and purification stage due to sulfuric acid back-extraction, and industrial lime will also introduce magnesium impurities.

[0005] Therefore, removing iron, aluminum, and fluoride ions from ternary leachate through a one-step sedimentation method, while avoiding the introduction of calcium and magnesium impurities, has significant application potential. Summary of the Invention

[0006] In view of the problems existing in the prior art, namely, the impurity removal treatment of ternary lithium battery leachate before extraction often introduces Ca and Mg impurities, the present invention provides a one-step impurity removal treatment method for ternary lithium battery leachate. By introducing a portion of aluminum source, controlling the Al / F molar ratio in the solution system to ≥4, and then adding an alkaline source to adjust the pH for precipitation treatment, Fe, Al and F can be removed by precipitation in one step without introducing other elements such as Ca and Mg. It has the advantages of simple operation, simple equipment, low energy consumption and no pollution.

[0007] To achieve this objective, the present invention adopts the following technical solution:

[0008] The purpose of this invention is to provide a one-step impurity removal method for ternary lithium battery leachate from waste power batteries. The one-step impurity removal method for ternary lithium battery leachate from waste power batteries includes the following steps:

[0009] Prepare a ternary lithium battery leachate solution from waste power batteries and heat it. First, add an aluminum source until it is completely dissolved, and control the Al / F molar ratio in the solution system to be ≥4. Then, add an alkaline source for precipitation treatment. After solid-liquid separation, obtain a liquid after one-step impurity removal.

[0010] The one-step purification method for ternary lithium battery leachate of the present invention introduces a portion of aluminum source, controls the Al / F molar ratio in the solution system to be ≥4, and then adds an alkaline source to adjust the pH for precipitation treatment, thereby achieving one-step precipitation purification of Fe, Al, and F without introducing other elements such as Ca and Mg. It has the advantages of simple operation, simple equipment, low energy consumption, and no pollution.

[0011] Experimental studies have shown that if the Al / F molar ratio after adding an aluminum source is less than 4, the subsequent addition of an alkaline source will result in less precipitation, weakening the adsorption of F ions and affecting the impurity removal effect.

[0012] As a preferred technical solution of the present invention, the source of the ternary lithium-ion battery leachate includes: black powder obtained by dismantling, crushing, and screening waste power batteries, followed by leaching with sulfuric acid and hydrogen peroxide to obtain the ternary lithium-ion leachate. It should be noted that after leaching with sulfuric acid and hydrogen peroxide, not only can Ni, Co, and Mn be leached in the form of low-valence ions, but also ferrous iron can be oxidized to ferric iron in the hydrogen peroxide environment.

[0013] As a preferred technical solution of the present invention, the ternary leachate from the waste power battery contains 3-5 g / L of F, 0.7-0.9 g / L of Fe, and 10-12 g / L of Al.

[0014] It should be noted that, as is well known to those skilled in the art, the ternary leaching solution of waste power batteries described in this invention contains a high concentration of nickel, cobalt, and manganese. However, this invention focuses on the impurity removal treatment before the extraction operation and pays more attention to the content of impurity elements such as F, Fe, and Al. Therefore, this invention does not limit the specific concentration of nickel, cobalt, and manganese.

[0015] As a preferred technical solution of the present invention, the target temperature of the heating treatment is 60-80℃, such as 60℃, 61℃, 63℃, 65℃, 67℃, 70℃, 72℃, 75℃, 78℃ or 80℃.

[0016] As a preferred embodiment of the present invention, the aluminum source includes aluminum sulfate octadecahydrate.

[0017] As a preferred technical solution of the present invention, an aluminum source is added until it is completely dissolved, and the Al / F molar ratio in the solution system is controlled to be 4-10, for example, Al / F molar ratio of 4, Al / F molar ratio of 4.5, Al / F molar ratio of 5, Al / F molar ratio of 5.5, Al / F molar ratio of 6, Al / F molar ratio of 6.5, Al / F molar ratio of 7, Al / F molar ratio of 7.5, Al / F molar ratio of 8, Al / F molar ratio of 8.5, Al / F molar ratio of 9, or Al / F molar ratio of 10, etc.

[0018] As a preferred embodiment of the present invention, the alkali source includes any one or a combination of at least two of sodium carbonate, sodium bicarbonate, sodium hydroxide, nickel hydroxide, or MHP.

[0019] It should be noted that, as is well known to those skilled in the art, MHP refers to nickel cobalt hydroxide, such as a nickel intermediate prepared from laterite nickel ore using high-pressure acid leaching technology. MHP is alkaline and has low levels of F, Fe, and Al impurities, making it perfectly suitable as an alkali source for this invention.

[0020] As a preferred technical solution of the present invention, an alkaline source is added to adjust the pH of the reaction system to 4.5-5, for example, the pH of the reaction system is 4.5, 4.6, 4.7, 4.8, 4.9, or 5, etc.

[0021] As a preferred technical solution of the present invention, the precipitation treatment time is 2-5 hours, such as 2 hours, 2.2 hours, 2.5 hours, 2.8 hours, 3 hours, 3.2 hours, 3.5 hours, 3.8 hours, 4 hours, 4.2 hours, 4.5 hours, 4.8 hours or 5 hours.

[0022] As a preferred embodiment of the present invention, the F content in the liquid after the first step of impurity removal is less than 100 mg / L, the Fe content is less than 10 mg / L, and the Al content is less than 10 mg / L.

[0023] Compared with existing technical solutions, the present invention has at least the following beneficial effects:

[0024] (1) The one-step impurity removal method for waste power battery ternary leaching solution of the present invention introduces a portion of aluminum source, controls the Al / F molar ratio in the solution system to be ≥4, and then adds an alkaline source to adjust the pH for precipitation treatment, thereby achieving the purpose of simultaneous precipitation of iron, aluminum and fluorine, and solving the problems of calcium and magnesium impurities introduced into the ternary leaching solution and high fluorine concentration in the prior art due to impurity removal.

[0025] (2) The one-step impurity removal method for ternary leaching solution of waste power battery described in this invention achieves the purpose of low-cost impurity removal of ternary leaching solution without introducing new impurities by introducing an aluminum source for one-step precipitation, and has important application prospects.

[0026] (3) The one-step impurity removal method for ternary leaching solution of waste power battery described in this invention has the advantages of simple operation, simple equipment, low energy consumption and no pollution. Detailed Implementation

[0027] To facilitate understanding of the present invention, the following embodiments are provided. Those skilled in the art should understand that these embodiments are merely illustrative and should not be construed as limiting the scope of the invention.

[0028] This invention provides a one-step impurity removal method for ternary lithium battery leachate from waste power batteries, the method comprising the following steps:

[0029] Step S1: Prepare a ternary lithium-ion battery leachate. The source of the ternary lithium-ion battery leachate includes: black powder obtained by dismantling, crushing and screening waste power batteries, and leaching it with sulfuric acid and hydrogen peroxide. The ternary lithium-ion battery leachate contains 3-5 g / L of F, 0.7-0.9 g / L of Fe, and 10-12 g / L of Al. Heat the solution to 60-80℃, add aluminum sulfate octadecahydrate according to an Al / F molar ratio ≥4, and stir thoroughly until completely dissolved.

[0030] Step S2: Add an alkali source to the liquid obtained in step S1, adjust the pH of the reaction system to 4.5-5, stir at 60-80℃ for 2-5 hours for precipitation treatment, and obtain a one-step impurity-removed liquid after solid-liquid separation. The one-step impurity-removed liquid has an F content of less than 100 mg / L, an Fe content of less than 10 mg / L, and an Al content of less than 10 mg / L.

[0031] In the specific embodiments of the present invention, the source of the ternary leachate from waste power batteries is: black powder obtained by dismantling, crushing and screening waste power batteries, and then leaching it with sulfuric acid and hydrogen peroxide. After the black powder is leached with sulfuric acid and hydrogen peroxide, not only can Ni, Co and Mn be leached in the form of low-valence ions, but also ferrous iron can be oxidized to ferric iron in the hydrogen peroxide environment.

[0032] Example 1

[0033] This embodiment provides a one-step impurity removal method for ternary lithium battery leachate, which includes the following steps:

[0034] Step S1: Measure 4L of ternary lithium battery leachate from waste power batteries, with F content of 4.1g / L, Fe content of 829.1mg / L, and Al content of 11.64g / L. Pour it into a glass reactor, heat it to 60℃, and add aluminum sulfate octadecahydrate according to the Al / F molar ratio of 4. Stir thoroughly until completely dissolved.

[0035] Step S2: Add sodium carbonate as an alkali source to the liquid obtained in step S1, adjust the pH of the reaction system to 4.5, stir at 60℃ for 2 hours for precipitation treatment, and filter to obtain the liquid after one-step impurity removal; after testing and analysis, the F content in the liquid after one-step impurity removal is 75.03 mg / L, the Fe content is 0.1 mg / L, and the Al content is 9.6 mg / L.

[0036] Example 2

[0037] This embodiment provides a one-step impurity removal method for ternary lithium battery leachate, which includes the following steps:

[0038] Step S1: Measure 4L of ternary lithium battery leachate from waste power batteries, with F content of 4.1g / L, Fe content of 829.1mg / L, and Al content of 11.64g / L. Pour it into a glass reactor, heat it to 80℃, and add aluminum sulfate octadecahydrate according to the Al / F molar ratio of 5. Stir thoroughly until completely dissolved.

[0039] Step S2: Add sodium carbonate as an alkali source to the liquid obtained in step S1, adjust the pH of the reaction system to 5, stir at 80℃ for 2 hours for precipitation treatment, and filter to obtain the liquid after one-step impurity removal; after testing and analysis, the F content in the liquid after one-step impurity removal is 24.70 mg / L, the Fe content is 0.1 mg / L, and the Al content is 4.2 mg / L.

[0040] Example 3

[0041] This embodiment provides a one-step impurity removal method for ternary lithium battery leachate, which includes the following steps:

[0042] Step S1: Measure 4L of ternary lithium battery leachate from waste power batteries, with F content of 4.1g / L, Fe content of 829.1mg / L, and Al content of 11.64g / L. Pour it into a glass reactor, heat it to 60℃, and add aluminum sulfate octadecahydrate according to the Al / F molar ratio of 5. Stir thoroughly until completely dissolved.

[0043] Step S2: Add sodium carbonate as an alkali source to the liquid obtained in step S1, adjust the pH of the reaction system to 5, stir at 60℃ for 2 hours for precipitation treatment, and filter to obtain the liquid after one-step impurity removal; after testing and analysis, the F content in the liquid after one-step impurity removal is 65.30 mg / L, the Fe content is 0.1 mg / L, and the Al content is 6.3 mg / L.

[0044] Example 4

[0045] This embodiment provides a one-step impurity removal method for ternary lithium battery leachate, which includes the following steps:

[0046] Step S1: Measure 4L of ternary lithium battery leachate from waste power batteries, with F content of 4.1g / L, Fe content of 829.1mg / L, and Al content of 11.64g / L. Pour it into a glass reactor, heat it to 60℃, and add aluminum sulfate octadecahydrate according to the Al / F molar ratio of 7. Stir thoroughly until completely dissolved.

[0047] Step S2: Add sodium carbonate as an alkali source to the liquid obtained in step S1, adjust the pH of the reaction system to 4.5, stir at 60°C for 2 hours for precipitation treatment, and filter to obtain a one-step impurity-removed liquid; after testing and analysis, the F content in the one-step impurity-removed liquid is 20.37 mg / L, the Fe content is 0.1 mg / L, and the Al content is 9.82 mg / L; compared with the one-step impurity-removed liquid of Example 1, the F content in this example is significantly reduced.

[0048] Example 5

[0049] This embodiment provides a one-step impurity removal method for ternary lithium battery leachate, which includes the following steps:

[0050] Step S1: Measure 4L of ternary lithium battery leachate from waste power batteries, with F content of 4.1g / L, Fe content of 829.1mg / L, and Al content of 11.64g / L. Pour it into a glass reactor, heat it to 60℃, and add aluminum sulfate octadecahydrate according to the Al / F molar ratio of 10. Stir thoroughly until completely dissolved.

[0051] Step S2: Add sodium carbonate as an alkali source to the liquid obtained in step S1, adjust the pH of the reaction system to 4.5, stir at 60°C for 2 hours for precipitation treatment, and filter to obtain a one-step impurity-removed liquid; after testing and analysis, the F content in the one-step impurity-removed liquid is 15.44 mg / L, the Fe content is 0.1 mg / L, and the Al content is 9.61 mg / L; compared with the one-step impurity-removed liquid of Example 1, the F content in this example is significantly reduced.

[0052] Example 6

[0053] This embodiment provides a one-step impurity removal method for ternary lithium battery leachate, which includes the following steps:

[0054] Step S1: Measure 4L of ternary lithium battery leachate from waste power batteries, with F content of 4.1g / L, Fe content of 829.1mg / L, and Al content of 11.64g / L. Pour it into a glass reactor, heat it to 60℃, and add aluminum sulfate octadecahydrate according to the Al / F molar ratio of 11. Stir thoroughly until completely dissolved.

[0055] Step S2: Add sodium carbonate as an alkali source to the liquid obtained in step S1, adjust the pH of the reaction system to 4.5, stir at 60°C for 2 hours for precipitation treatment, and filter to obtain the liquid after one-step impurity removal; after testing and analysis, the F content in the liquid after one-step impurity removal is 14.96 mg / L, the Fe content is 0.5 mg / L, and the Al content is 11.7 mg / L; compared with the liquid after one-step impurity removal in Example 1, the F content in this example is significantly reduced, but the Al content is significantly increased, which is not conducive to subsequent impurity removal and will increase the cost of using chemical agents.

[0056] Example 7

[0057] This embodiment provides a one-step impurity removal method for ternary lithium battery leachate, which includes the following steps:

[0058] Step S1: Measure 4L of ternary lithium battery leachate from waste power batteries, with F content of 4.1g / L, Fe content of 829.1mg / L, and Al content of 11.64g / L. Pour it into a glass reactor, heat it to 60℃, and add aluminum sulfate octadecahydrate according to the Al / F molar ratio of 4. Stir thoroughly until completely dissolved.

[0059] Step S2: Add sodium carbonate as an alkali source to the liquid obtained in step S1, adjust the pH of the reaction system to 4, stir at 60°C for 2 hours for precipitation treatment, and filter to obtain a one-step impurity-removed liquid; after testing and analysis, the F content in the one-step impurity-removed liquid is 103.4 mg / L, the Fe content is 7.11 mg / L, and the Al content is 12.13 mg / L; compared with the one-step impurity-removed liquid of Example 1, the F content, Fe content, and Al content of this example are all increased, and the F and Al contents exceed the standard.

[0060] Example 8

[0061] This embodiment provides a one-step impurity removal method for ternary lithium battery leachate, which includes the following steps:

[0062] Step S1: Measure 4L of ternary lithium battery leachate from waste power batteries, with F content of 4.1g / L, Fe content of 829.1mg / L, and Al content of 11.64g / L. Pour it into a glass reactor, heat it to 60℃, and add aluminum sulfate octadecahydrate according to the Al / F molar ratio of 4. Stir thoroughly until completely dissolved.

[0063] Step S2: Add sodium carbonate as an alkali source to the liquid obtained in step S1, adjust the pH of the reaction system to 5.5, stir at 60°C for 2 hours for precipitation treatment, and filter to obtain the first-step impurity-removed liquid; after testing and analysis, the F content in the first-step impurity-removed liquid is 25.15 mg / L, the Fe content is 0.1 mg / L, and the Al content is 8.83 mg / L; compared with the first-step impurity-removed liquid of Example 1, the F and Al contents in this example are significantly reduced, indicating that adding an alkali source to adjust the pH of the reaction system to a higher level is beneficial for impurity removal, but it will lead to a greater loss of Ni, Co, and Mn main elements, which is not conducive to the subsequent extraction process.

[0064] Comparative Example 1

[0065] This embodiment provides a method for treating ternary lithium battery leachate, the method comprising the following steps:

[0066] Step S1: Measure 4L of ternary lithium battery leachate from waste power batteries, with F content of 4.1g / L, Fe content of 829.1mg / L, and Al content of 11.64g / L. Pour it into a glass reactor, heat it to 60℃, and add aluminum sulfate octadecahydrate according to the Al / F molar ratio of 3. Stir thoroughly until completely dissolved.

[0067] Step S2: Add sodium carbonate as an alkali source to the liquid obtained in step S1, adjust the pH of the reaction system to 4.5, stir at 60°C for 2 hours for precipitation treatment, and filter to obtain the liquid after one-step impurity removal. After testing and analysis, the F content in the liquid after one-step impurity removal is 144.97 mg / L, the Fe content is 2.55 mg / L, and the Al content is 11.21 mg / L. Compared with the liquid after one-step impurity removal in Example 1, the F content, Fe content, and Al content in this comparative example are significantly increased and far exceed the standard, failing to meet the standard of "F content less than 100 mg / L, Fe content less than 10 mg / L, and Al content less than 10 mg / L".

[0068] In summary, the one-step impurity removal method for ternary lithium battery leachate of the present invention, by introducing a portion of aluminum source and controlling the Al / F molar ratio in the solution system to ≥4, and then adding an alkaline source to adjust the pH for precipitation treatment, achieves the simultaneous precipitation of iron, aluminum, and fluorine. This solves the problems of calcium and magnesium impurities and high fluorine concentration in ternary lithium leachate due to impurity removal in existing technologies. The present invention achieves low-cost impurity removal of ternary lithium leachate without introducing new impurities by introducing an aluminum source for one-step precipitation, which has significant application prospects and advantages such as simple operation, simple equipment, low energy consumption, and no pollution.

[0069] This invention illustrates the detailed process equipment and process flow through the above embodiments. However, this invention is not limited to the detailed process equipment and process flow described above, meaning that this invention does not necessarily depend on the detailed process equipment and process flow to be implemented. Those skilled in the art should understand that any improvements to this invention, equivalent substitutions of raw materials for the product of this invention, addition of auxiliary components, and selection of specific methods, all fall within the protection scope and disclosure scope of this invention.

Claims

1. A one-step method for removing impurities from ternary lithium battery leachate, characterized in that, The one-step impurity removal method for the ternary lithium battery leachate of waste power batteries includes the following steps: Prepare a ternary lithium battery leaching solution and heat it. First, add an aluminum source until it is completely dissolved and control the Al / F molar ratio in the solution system to be ≥4. Then, add an alkaline source and adjust the pH of the reaction system to 4.5-5. Perform precipitation treatment and solid-liquid separation to obtain a one-step impurity-removed solution. The sources of the ternary lithium-ion battery leachate include: black powder obtained by dismantling, crushing and screening waste power batteries, and then leaching it with sulfuric acid and hydrogen peroxide to obtain the ternary lithium-ion battery leachate; the ternary lithium-ion battery leachate contains 3-5 g / L of F, 0.7-0.9 g / L of Fe, and 10-12 g / L of Al. The liquid after the first step of impurity removal has an F content of less than 100 mg / L, an Fe content of less than 10 mg / L, and an Al content of less than 10 mg / L. The one-step impurity removal method for ternary lithium battery leachate is aimed at the impurity removal process before the extraction operation.

2. The one-step impurity removal method for ternary lithium battery leachate according to claim 1, characterized in that, The target temperature for the heating process is 60-80℃.

3. The one-step impurity removal method for ternary lithium battery leachate according to claim 1, characterized in that, The aluminum source includes aluminum sulfate octadechydrate.

4. The one-step impurity removal method for ternary lithium battery leachate according to claim 1, characterized in that, Add aluminum source until completely dissolved, and control the Al / F molar ratio in the solution system to be 4-10.

5. The one-step impurity removal method for ternary lithium battery leachate according to claim 1, characterized in that, The alkali source includes any one or a combination of at least two of sodium carbonate, sodium bicarbonate, sodium hydroxide, nickel hydroxide, or MHP.

6. The one-step impurity removal method for ternary lithium battery leachate according to claim 1, characterized in that, The precipitation treatment time is 2-5 hours.