Method for selectively extracting and separating and recovering impurity iron and aluminum from waste ternary lithium battery sulfuric acid leaching solution

Abstract

The application discloses a method for selectively extracting, removing and separating and recovering impurity iron and aluminum from waste ternary lithium battery sulfuric acid leaching solution, which adopts N1923-TBP-sulfonated kerosene mixed extractant to extract the waste ternary lithium battery sulfuric acid leaching solution, so as to obtain an iron and aluminum containing loaded organic phase and a raffinate liquid phase after the iron and aluminum are removed; hydrochloric acid is used to back-extract the iron and aluminum containing loaded organic phase, so as to obtain an aluminum chloride back-extraction liquid and an iron containing loaded organic phase; nitric acid is used to back-extract the iron containing loaded organic phase, so as to obtain a ferric nitrate solution. The application can realize selective removal of impurities Fe 3+ , Al 3+ in the waste ternary lithium battery sulfuric acid leaching solution and separation and recovery between the impurities Fe 3+ and Al 3+ , and has the advantages of simple operation, good separation effect and high recovery efficiency.

Description

Technical Field

[0001] This invention relates to the field of hydrometallurgical technology, specifically to a method for selectively extracting, removing, separating, and recovering impurities iron and aluminum from sulfuric acid leachate of waste ternary lithium batteries. Background Technology

[0002] Compared to traditional batteries, lithium-ion batteries offer advantages such as higher energy density, longer cycle life, lower self-discharge, no memory effect, lighter weight, and smaller size. In recent years, the development of the new energy vehicle industry has driven the widespread adoption of ternary lithium-ion batteries, which have a greater advantage in energy density. With the continuous upgrading of new energy vehicles, a large number of used ternary lithium batteries are generated, representing an important secondary resource.

[0003] Currently, the valuable metals of waste ternary lithium battery materials are mainly recovered through hydrometallurgical processes. After initial discharge, dismantling, crushing, and sulfuric acid leaching, valuable metals Ni, Co, Mn, and Li, along with major impurities Fe and Al, enter the sulfuric acid leaching solution. Effectively and selectively removing and separating the impurities Fe and Al from the leaching solution is crucial for the subsequent recovery of valuable metals Ni, Co, Mn, and Li, and the resource utilization of impurities Fe and Al.

[0004] Although solvent extraction is currently the most studied and industrially feasible method for metal separation, existing extractant systems and extraction technologies are difficult to apply effectively to the direct selective extraction and separation of impurities Fe and Al in this sulfuric acid leaching system. This greatly limits the recovery of valuable metals Ni, Co, Mn, and Li, as well as the resource utilization of impurity metals Fe and Al.

[0005] In view of this, the present invention is proposed. Summary of the Invention

[0006] The purpose of this invention is to provide a method for selectively extracting, removing, separating, and recovering impurities iron and aluminum from sulfuric acid leachate of waste ternary lithium batteries.

[0007] This invention is achieved through the following technical solutions:

[0008] A method for selectively extracting, removing, and separating and recovering impurities iron and aluminum from sulfuric acid leachate of spent ternary lithium batteries, the method comprising the following steps:

[0009] 1) The sulfuric acid leachate from waste ternary lithium batteries was extracted using a mixed extractant of N1923-TBP-sulfonated kerosene until the pH of the aqueous phase reached 4.25-4.7. After phase separation, an organic phase containing iron and aluminum and an aqueous raffinate after removing iron and aluminum were obtained. The N1923-TBP-sulfonated kerosene mixed extractant was prepared by mixing N1923, TBP, and sulfonated kerosene in a volume ratio of 1-3:1-2:5-8. The sulfuric acid leachate from waste ternary lithium batteries contains the main metal Ni. 2+ 10-15 g / L, Co 2+ 5~10g / L, Mn 2+ 5~10g / L, Li + 1–5 g / L, and impurity metal Fe 3+ 0.5~3g / L and Al 3+ 1~3g / L;

[0010] 2) The iron- and aluminum-supported organic phase obtained in step 1) is back-extracted with hydrochloric acid to obtain an iron-supported organic phase and an aluminum chloride back-extraction solution;

[0011] 3) The iron-supported organic phase obtained in step 2) is back-extracted with nitric acid to obtain an iron nitrate solution.

[0012] Preferably, the pH of the sulfuric acid leachate from waste ternary lithium batteries is 0 to 2.5.

[0013] Preferably, step 1) extraction uses countercurrent or crosscurrent extraction; the extraction ratio O / A is (1-3):1; the number of extraction stages is 1-3; and the extraction time is 5-10 min.

[0014] Preferably, in step 2), the iron- and aluminum-supported organic phase is back-extracted using hydrochloric acid in a countercurrent manner. The concentration of hydrochloric acid is 6–12 mol / L, the O / A ratio in the back-extraction is 1:(1–3), the number of countercurrent back-extraction stages is 1–3, and the countercurrent back-extraction time is 5–10 min.

[0015] Preferably, in step 3), the iron-supported organic phase is back-extracted using nitric acid countercurrently, with the concentration of nitric acid being 1–3 mol / L, the O / A ratio being 1:(1–3), the number of countercurrent back-extraction stages being 1–3, and the countercurrent back-extraction time being 5–10 min.

[0016] The beneficial effects of this invention are as follows: This invention ingeniously utilizes the N1923-TBP-sulfonated kerosene mixed extractant in specific H+ ions of sulfuric acid, hydrochloric acid, and nitric acid systems. + For impurity Fe within the concentration range 3+ And Al 3+ and the main metal Ni 2+ Co 2+ Mn 2+ Li +The differences in extraction characteristics between them ultimately led to the removal of Fe impurities from the sulfuric acid leachate of spent ternary lithium batteries. 3+ Al 3+ Selective removal of Fe impurities 3+ With Al 3+ The separation and recycling process is simple, effective, and efficient. Detailed Implementation

[0017] The following is a further description of the invention, but not a limitation thereof. Unless otherwise specified, the equipment and reagents used in this invention are commercially available products conventional in this technical field.

[0018] Example 1: A method for selectively extracting, removing, and separating and recovering impurities iron and aluminum from sulfuric acid leachate of spent ternary lithium batteries.

[0019] The composition of sulfuric acid leachate from waste ternary lithium batteries is as follows: Ni 2+ 14.09 g / L, Co 2+ 6.26 g / L, Mn 2+ 6.92 g / L, Li + 4.04 g / L, Fe 3+ 0.89 g / L, Al 3+ 2.98 g / L. pH = 1.05. An extraction organic phase was prepared by volume ratio of 30% N1923, 10% TBP, and 60% sulfonated kerosene. The sulfuric acid leachate from waste ternary lithium batteries and the extraction organic phase were subjected to a first-stage countercurrent extraction at an O / A ratio of 1:1 for 10 min, until the pH of the aqueous phase reached 4.67, and the impurity Fe was removed. 3+ 100% extraction rate, Al 3+ Extraction rate 99.92%, main metal Ni 2+ Co 2+ Mn 2+ Li + Extraction loss rate <1%. The iron- and aluminum-supported organic phase was subjected to three-stage countercurrent back-extraction with 6 mol / L hydrochloric acid at a ratio (O / A) of 1:1 for 5 min. 3+ Not being recycled, Al 3+ The back-extraction rate was 100%, yielding an iron-supported organic phase and an aluminum chloride solution. Three-stage countercurrent back-extraction was performed using 3 mol / L nitric acid at a ratio (O / A) of 1:3 for 10 min each time. Fe... 3+ The back-extraction rate was 99.36%, yielding a ferric nitrate solution; this method effectively removed Fe impurities from the sulfuric acid leachate of spent ternary lithium batteries. 3 + Al 3+ Selective removal of Fe impurities 3+ With Al 3+ Separation and recovery between them, calculation of Fe3+ Recovery rate 99.36%, Al 3+ Recovery rate: 99.92%.

[0020] Example 2: A method for selectively extracting, removing, and separating and recovering impurities iron and aluminum from sulfuric acid leachate of spent ternary lithium batteries.

[0021] The composition of sulfuric acid leachate from waste ternary lithium batteries is as follows: Ni 2+ 14.09 g / L, Co 2+ 6.26 g / L, Mn 2+ 6.92 g / L, Li + 4.04 g / L, Fe 3+ 0.89 g / L, Al 3+ 2.98 g / L. pH = 2.5. An extraction organic phase was prepared by volume ratio of 10% N1923, 10% TBP, and 80% sulfonated kerosene. The sulfuric acid leachate from waste ternary lithium batteries and the extraction organic phase were subjected to a 3-stage countercurrent extraction at an O / A ratio of 1:1 for 10 min, until the pH of the aqueous phase reached 4.49, and the impurity Fe was removed. 3+ Extraction rate 99.01%, Al 3+ Extraction rate 98.73%, main metal Ni 2+ Co 2+ Mn 2+ Li + Extraction loss rate <1%. The iron- and aluminum-supported organic phase was subjected to a first-stage countercurrent back-extraction with 12 mol / L hydrochloric acid at a ratio (O / A) of 1:3 for 10 min. 3+ Not washed, Al 3+ The back-extraction rate was 99.03%, yielding an iron-supported organic phase and an aluminum chloride solution. Three-stage countercurrent back-extraction was performed using 1 mol / L nitric acid at a ratio (O / A) of 1:3 for 10 min. Fe... 3+ The back-extraction rate was 97.83%, yielding a ferric nitrate solution; this method effectively removed Fe impurities from the sulfuric acid leachate of spent ternary lithium batteries. 3+ Al 3+ Selective removal of Fe impurities 3+ With Al 3+ Separation and recovery between them, calculation of Fe 3+ Recovery rate 96.86%, Al 3+ Recovery rate: 97.77%.

[0022] Example 3: A method for selectively extracting, removing, and separating and recovering impurities iron and aluminum from sulfuric acid leachate of spent ternary lithium batteries.

[0023] The composition of sulfuric acid leachate from waste ternary lithium batteries is as follows: Ni 2+ 11.28 g / L, Co2+ 9.73 g / L, Mn 2+ 8.74 g / L, Li + 2.19 g / L, Fe 3+ 2.78 g / L, Al 3+ 2.19 g / L. pH = 0. An extraction organic phase was prepared by volume ratio of 30% N1923, 20% TBP, and 50% sulfonated kerosene. The sulfuric acid leachate from waste ternary lithium batteries and the extraction organic phase were subjected to a three-stage cross-flow extraction at a ratio of O / A of 1:1 for 5 min, until the pH of the aqueous phase reached 4.31. Impurities were Fe. 3+ Extraction rate 97.25%, Al 3+ Extraction rate 96.87%, main metal Ni 2+ Co 2+ Mn 2+ Li + Extraction loss rate <1%. The iron- and aluminum-supported organic phase was subjected to a first-stage countercurrent back-extraction with 6 mol / L hydrochloric acid at a ratio (O / A) of 1:1 for 5 min. 3+ Not washed, Al 3+ The back-extraction rate was 98.25%, yielding an iron-supported organic phase and an aluminum chloride solution. Three-stage countercurrent back-extraction was performed using 1 mol / L nitric acid at a ratio (O / A) of 1:3 for 10 min. Fe... 3+ The back-extraction rate was 98.93%, yielding a ferric nitrate solution; this method effectively removed Fe impurities from the sulfuric acid leachate of spent ternary lithium batteries. 3+ Al 3+ Selective removal of Fe impurities 3+ With Al 3+ Separation and recovery between them, calculation of Fe 3+ Recovery rate 96.21%, Al 3+ Recovery rate: 95.17%.

[0024] Example 4: A method for selectively extracting, removing, separating, and recovering impurities iron and aluminum from sulfuric acid leachate of spent ternary lithium batteries.

[0025] The composition of sulfuric acid leachate from waste ternary lithium batteries is as follows: Ni 2+ 14.09 g / L, Co 2+ 6.26 g / L, Mn 2+ 6.92 g / L, Li + 4.04 g / L, Fe 3+ 0.89 g / L, Al 3+2.98 g / L. pH = 1.05. An extraction organic phase was prepared by volume ratio of 10% N1923, 15% TBP, and 75% sulfonated kerosene. The sulfuric acid leachate from waste ternary lithium batteries and the extraction organic phase were subjected to a two-stage countercurrent extraction at an O / A ratio of 3:1 for 10 min, until the pH of the aqueous phase reached 4.63, and the impurity Fe was removed. 3+ 100% extraction rate, Al 3+ Extraction rate 98.21%, main metal Ni 2+ Co 2+ Mn 2+ Li + Extraction loss rate <1%. The iron- and aluminum-supported organic phase was subjected to three-stage countercurrent back-extraction with 8 mol / L hydrochloric acid at a ratio (O / A) of 1:1 for 10 min. 3+ Not being recycled, Al 3+ The back-extraction rate was 100%, yielding an iron-supported organic phase and an aluminum chloride solution; three-stage countercurrent back-extraction was performed using 2 mol / L nitric acid at a ratio (O / A) of 1:1 for 10 min, with Fe... 3+ The back-extraction rate was 99.57%, yielding a ferric nitrate solution; this method effectively removed Fe impurities from the sulfuric acid leachate of spent ternary lithium batteries. 3 + Al 3+ Selective removal of Fe impurities 3+ With Al 3+ Separation and recovery between them, calculation of Fe 3+ Recovery rate 99.57%, Al 3+ Recovery rate: 98.21%.

[0026] Comparative Example 1

[0027] This comparative example is essentially the same as Example 1, except that TBP was not added during the extraction of the organic phase; instead, it consisted of 30% N1923 and 70% sulfonated kerosene by volume. Impurities: Fe. 3+ 100% extraction rate, Al 3+ Extraction rate 100%, main metal Ni 2+ Co 2+ Mn 2+ Li + Extraction loss rate: 21.22%. Hydrochloric acid back-extraction process, Fe... 3+ Al 3+ The back-extraction rate was 100%, which could not achieve selective extraction and removal of impurities such as iron and aluminum, or separation and recovery between iron and aluminum.

[0028] Comparative Example 2

[0029] This comparative example is essentially the same as Example 1, except that N1923 was not added when selecting the organic phase for extraction; the volume ratio was 10% TBP + 90% sulfonated kerosene. Impurities: Fe. 3+ Al 3+ and main metal Ni 2+ Co 2+ Mn 2+ Li + Neither of them are extracted, making it impossible to selectively extract and remove impurities such as iron and aluminum, or to separate and recover iron and aluminum.

[0030] Comparative Example 3

[0031] This comparative example is essentially the same as Example 1, except that N1923 and TBP were not added to the organic phase used for extraction, and 100% sulfonated kerosene was used by volume. Impurities Fe 3+ Al 3+ and main metal Ni 2+ Co 2+ Mn 2+ Li + Neither of them are extracted, making it impossible to selectively extract and remove impurities such as iron and aluminum, or to separate and recover iron and aluminum.

[0032] Comparative Example 4

[0033] This comparative example is essentially the same as Example 2, except that N235, a similar extractant, was used instead of N1923 for the organic phase extraction. The volume ratio was 10% N235, 10% TBP, and 80% sulfonated kerosene. Impurities: Fe. 3+ Extraction rate 37.26%, Al 3+ Extraction rate 11.49%, main metal Ni 2+ Co 2+ Mn 2+ Li + Neither of them are extracted, making it impossible to selectively extract and remove impurities such as iron and aluminum, or to separate and recover iron and aluminum.

[0034] Comparative Example 5

[0035] This comparative example is essentially the same as Example 2, except that N263, a similar extractant, was used instead of N1923 for the organic phase extraction. The volume ratio was 10% N263, 10% TBP, and 80% sulfonated kerosene. Impurities: Fe. 3+ Extraction rate 10.48%, Al 3+ Extraction rate 8.16%, main metal Ni 2+ Co 2+ Mn 2+ Li +Neither of them are extracted, making it impossible to selectively extract and remove impurities such as iron and aluminum, or to separate and recover iron and aluminum.

[0036] Comparative Example 6

[0037] This comparative example is basically the same as Example 2, except that the extraction organic phase used is, by volume ratio, 5% N1923, 10% TBP, and 85% sulfonated kerosene. The sulfuric acid leachate from waste ternary lithium batteries and the extraction organic phase were extracted to the aqueous phase endpoint at pH 3.58. Impurities Fe 3+ Extraction rate 83.79%, Al 3+ Extraction rate 22.68%, main metal Ni 2+ Co 2+ Mn 2+ Li + Neither of them are extracted, making it impossible to selectively extract and remove impurities such as iron and aluminum, or to separate and recover iron and aluminum.

[0038] Comparative Example 7

[0039] This comparative example is essentially the same as Example 3, except that P350, a similar extractant, was used instead of TBP for the organic phase extraction. The volume ratio was 30% N1923, 20% P350, and 50% sulfonated kerosene. Impurities: Fe. 3+ Extraction rate 97.42%, Al 3+ Extraction rate 96.89%, main metal Ni 2+ Co 2+ Mn 2+ Li + Extraction loss rate <1%; hydrochloric acid back-extraction process, Fe 3+ Back-extraction rate 25.08%, Al 3+ The back-extraction rate was 21.54%; it was impossible to achieve selective extraction and removal of impurities iron and aluminum, as well as separation and recovery between iron and aluminum.

[0040] Comparative Example 8

[0041] This comparative example is basically the same as Example 4, except that N263, a similar extractant, was used instead of N1923 for the organic phase, and P350, a similar extractant, was used instead of TBP. The volume ratio was 10% N263, 15% P350, and 75% sulfonated kerosene. Impurities Fe 3+ Extraction rate 8.19%, Al 3+ Extraction rate 4.33%, main metal Ni 2+ Co 2+ Mn 2+ Li + Neither of them are extracted, making it impossible to selectively extract and remove impurities such as iron and aluminum, or to separate and recover iron and aluminum.

[0042] Comparative Example 9

[0043] This comparative example is basically the same as Example 4, except that the iron- and aluminum-supported organic phase is back-extracted with 2 mol / L hydrochloric acid. 3+ Back-extraction rate 82.06%, Al 3+ The back-extraction rate was 95.43%, which was insufficient to achieve selective extraction and removal of impurities such as iron and aluminum, as well as separation and recovery between iron and aluminum.

[0044] By comparing the examples and comparative examples, it can be seen that the selective extraction and separation effects of impurities iron and aluminum in the comparative examples are far inferior to those in the examples. This demonstrates that the use of N1923-TBP-sulfonated kerosene mixed extractant for the selective extraction and separation of impurities iron and aluminum in the sulfuric acid leaching solution system of waste ternary lithium batteries is not a simple combination of extractants or a conventional replacement of similar extractants, but has an unexpected synergistic and significant gain effect. Furthermore, when the extraction method, number of stages, time, etc. are within the range required by this application, the selective extraction removal rate and separation recovery rate of impurities iron and aluminum can be further guaranteed.

[0045] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for selectively extracting, removing, and separating and recovering impurities iron and aluminum from sulfuric acid leachate of spent ternary lithium batteries, characterized in that, The method includes the following steps: 1) The sulfuric acid leachate from waste ternary lithium batteries was extracted using a mixed extractant of N1923-TBP-sulfonated kerosene until the pH of the aqueous phase reached 4.25-4.

7. After phase separation, an organic phase containing iron and aluminum and an aqueous raffinate phase after removing iron and aluminum were obtained. The main metal is Ni. 2+ Co 2+ Mn 2+ Li + Extraction loss rate <1%; The N1923-TBP-sulfonated kerosene mixed extractant was prepared from N1923, TBP, and sulfonated kerosene in a volume ratio of 1~3:1~2:5~8; the sulfuric acid leachate from waste ternary lithium batteries contains the main metal Ni. 2+ 10~15g / L, Co 2+ 5~10 g / L, Mn 2+ 5~10g / L, Li + 1~5 g / L, and impurity metal Fe 3+ 0.5~3g / L and Al 3+ 1~3g / L; 2) The iron- and aluminum-supported organic phase obtained in step 1) is back-extracted with hydrochloric acid to obtain an iron-supported organic phase and an aluminum chloride back-extraction solution; 3) The iron-supported organic phase obtained in step 2) is back-extracted with nitric acid to obtain an iron nitrate solution; In step 2), the concentration of hydrochloric acid is 6~12 mol / L; in step 3), the concentration of nitric acid is 1~3 mol / L.

2. The method according to claim 1, characterized in that, The pH of the sulfuric acid leachate from waste ternary lithium batteries is 0~2.

5.

3. The method according to claim 1, characterized in that, Step 1) Extraction is performed using countercurrent or cross-current extraction; the extraction ratio O / A is (1~3):1; the number of extraction stages is 1~3; and the extraction time is 5~10 min.

4. The method according to claim 1, characterized in that, Step 2) The iron- and aluminum-supported organic phase is back-extracted using hydrochloric acid in a countercurrent manner. The back-extraction ratio O / A is 1:(1~3); the number of countercurrent back-extraction stages is 1~3; and the countercurrent back-extraction time is 5~10 min.

5. The method according to claim 1, characterized in that, Step 3) The iron-supported organic phase is back-extracted using nitric acid countercurrently, with an O / A ratio of 1:(1~3); the number of countercurrent back-extraction stages is 1~3; and the countercurrent back-extraction time is 5~10 min.