Method for extracting and removing iron and aluminum from P204 recycled from waste battery material

Abstract

The invention relates to a method for extracting and removing iron and aluminum from P204 recycled from a waste battery material. The method comprises the following steps: extracting iron: carrying out three-stage counter-current extraction on ternary black powder leaching liquid and blank P204 in a ratio of 1: 1 to obtain iron-extracted liquid and an iron-extracted loaded organic phase; extracting aluminum: performing 8-10 stages of countercurrent mixing on the iron-extracted liquid and saponified P204 with the saponification rate of 20-40% to extract aluminum, so as to obtain iron and aluminum-extracted liquid and an aluminum-extracted loaded organic phase; washing: the aluminum extraction loaded organic phase enters a reverse extraction section after being washed by six-stage dilute acid due to entrainment of part of coextracted copper and manganese; carrying out reverse extraction regeneration: carrying out reverse extraction on iron and aluminum by using 4-6N hydrochloric acid after washing; after reverse extraction, an organic phase is washed with residual acid and then returns to the front end for extraction; through process optimization, the effects of high-efficiency separation, high-purity recovery, low-energy-consumption operation, high environmental protection economy and high industrial applicability are realized.

Description

Technical Field

[0001] The invention relates to the technical field of waste battery material recycling, and in particular to a P204 extraction and aluminum removal method for recycling waste battery materials. Background Art

[0002] The black mixture obtained after the old ternary lithium battery is discharged, disassembled, crushed, sorted and separated is called ternary black powder. Ternary black powder contains a large amount of valuable metals such as nickel, cobalt, manganese and lithium. The valuable metals in ternary black powder are usually recovered by hydrometallurgical process. The hydrometallurgical process includes an acid leaching process, that is, the battery powder reacts with water and sulfuric acid to obtain a leachate containing nickel, cobalt, manganese and lithium. However, impurity metals such as iron and aluminum easily enter the liquid phase during the acid leaching process, which brings great difficulties to the subsequent impurity removal process and affects the purity of the product. In the prior art, most of them use the method of directly adjusting the pH value of the acid leaching solution to remove iron and aluminum impurities in the acid leaching solution, but iron hydroxide and aluminum hydroxide are both insoluble colloids and difficult to filter, which has a great impact on the filter press in production.

[0003] Patent CN109449523B discloses a comprehensive recovery method for waste lithium-ion batteries. After selective leaching of waste lithium-ion batteries, the leachate is subjected to lithium precipitation to obtain battery-grade lithium carbonate; the leached residue is subjected to selective reduction leaching, and the pH at the leaching end point is controlled at 4.2-4.5. The leachate adopts a two-stage fractionation extraction process, firstly using di(2-ethylhexyl) phosphate (P204) as an extractant to extract impurities such as copper, iron, and manganese, and then selectively stripping is used during stripping to obtain a pure manganese sulfate solution, which is evaporated and crystallized to obtain a battery-grade manganese sulfate product; the P204 raffinate is subjected to C272 extraction of cobalt, and after stripping, a pure cobalt sulfate solution is obtained, which is evaporated and crystallized to obtain a battery-grade cobalt sulfate product; the C272 raffinate is a pure nickel sulfate solution, which is evaporated and crystallized to obtain a battery-grade nickel sulfate product. The above technology is only used to extract nickel from lithium batteries. In the multi-metal separation process, the separation efficiency of copper, iron and manganese impurities depends on multiple stripping. The recovery rate and purity of cobalt and nickel may be affected by the front-end impurity separation. At the same time, two extraction agents (P204 and C272) are required, which makes the waste liquid composition complicated and difficult to reuse.

[0004] Therefore, in order to extract valuable metals from lithium batteries, the present invention proposes a P204 extraction and aluminum removal method for recycling waste battery materials, which is applied in industrial production to reduce raw material waste and production pollution in various links. Summary of the invention

[0005] The present invention aims at the technical problems existing in the prior art and provides a P204 extraction and iron and aluminum removal method for recycling waste battery materials.

[0006] The technical solution of the present invention to solve the above technical problems is as follows: a P204 extraction and aluminum removal method for recycling waste battery materials; comprising the following steps: Iron extraction: The ternary black powder leachate was subjected to three-stage countercurrent extraction at a ratio of 1:1 to blank P204 to obtain an iron-extracted liquid and an iron-extracted organic phase; Aluminum extraction: The iron-extracted liquid and the saponified P204 with a saponification rate of 20%-40% are mixed in 8-10 stages of countercurrent to extract aluminum, and the iron-extracted aluminum liquid and the aluminum-extracted organic phase are obtained; Washing: The aluminum-loaded organic phase carries some copper and manganese, and enters the stripping section after 6 levels of dilute acid washing; Stripping regeneration: After washing, the organic phase is stripped of iron and aluminum with 4-6N hydrochloric acid; after stripping, the organic phase is washed with water and the residual acid is returned to the front end for extraction.

[0007] Furthermore, in the method for extracting iron and aluminum from P204 for recycling waste battery materials, in the iron extraction step, the volume ratios of the leachate and blank P204 in the three-stage countercurrent extraction are: 2:1 for the first time, 2:1 for the second time, and 1:1 for the third time.

[0008] Furthermore, in the P204 extraction and aluminum removal method for recycling waste battery materials, the extraction temperature of the iron extraction step is controlled at 25-50°C.

[0009] Furthermore, in the P204 extraction and removal of iron and aluminum method for recycling waste battery materials, the pH value of the liquid outlet after iron and aluminum extraction is controlled to be 2.5-3.5.

[0010] Furthermore, in the method for extracting and removing iron and aluminum from P204 recycled from waste battery materials, the volume ratio of the iron-extracted liquid to the saponified P204 with a saponification rate of 20%-40% is 4:1.

[0011] Furthermore, the P204 extraction and removal of iron and aluminum method for recycling waste battery materials requires standing for stratification after washing, separating the washing liquid and the organic phase, and recovering the residual organic phase with 4-6N hydrochloric acid.

[0012] The beneficial effects of the present invention are: The present invention achieves the effects of efficient separation, high-purity recovery, low-energy operation, strong environmental protection and economic efficiency, and high industrial applicability through process optimization. Compared with the traditional waste battery material recovery process, the present invention has significant advantages and is a green, economical and efficient solution for the separation and recovery of iron and aluminum in waste battery materials, which is particularly suitable for large-scale industrial applications; Metal separation rate: The removal rate of iron and aluminum ions reached more than 99.9%, effectively retaining the valuable metals in battery waste; Environmental performance: single extraction agent system, single type of waste liquid, recycling of washing liquid, small waste liquid discharge and low energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 The present invention is a schematic flow chart of a P204 extraction and removal of iron and aluminum method for recycling waste battery materials. DETAILED DESCRIPTION

[0014] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of this application.

[0015] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, "plurality" means two or more, unless otherwise clearly and specifically defined.

[0016] In the description of the present application, the term "for example" is used to mean "used as an example, illustration or description". Any embodiment described as "for example" in the present application is not necessarily to be construed as being more preferred or advantageous than other embodiments. In order to enable any technician in the field to implement and use the present invention, the following description is given. In the following description, details are listed for the purpose of explanation. It should be understood that a person of ordinary skill in the art can recognize that the present invention can be implemented without using these specific details. In other examples, well-known structures and processes will not be elaborated in detail to avoid unnecessary details that make the description of the present invention obscure. Therefore, the present invention is not intended to be limited to the embodiments shown, but is consistent with the widest scope consistent with the principles and features disclosed in the present application.

[0017] like Figure 1 As shown: A P204 extraction and aluminum removal method for recycling waste battery materials, comprising the following steps: Iron extraction: The ternary black powder leachate was subjected to three-stage countercurrent extraction at a ratio of 1:1 to blank P204 to obtain an iron-extracted liquid and an iron-extracted organic phase; Aluminum extraction: The iron-extracted liquid and saponified P204 with a saponification rate of 20%-40% are mixed in 8-10 stages of countercurrent to extract aluminum, to obtain the iron-extracted aluminum liquid and the aluminum-extracted organic phase, and the outlet pH of the iron-extracted aluminum liquid is controlled at 2.5-3.5; Washing: The aluminum-loaded organic phase carries some copper and manganese, and enters the stripping section after 6 levels of dilute acid washing; Stripping regeneration: After washing, the organic phase is stripped of iron and aluminum with 4-6N hydrochloric acid. The main components of the stripping solution are ferric chloride and aluminum chloride, which do not need to be recycled and directly enter the sewage treatment. After stripping, the organic phase is washed with water and the residual acid is returned to the front-end extraction.

[0018] In this embodiment, the method of extracting and removing iron and aluminum is generally used in industrial production to increase the speed of industrial production. In the iron extraction step, the main component of blank P204 is di(2-ethylhexyl) phosphate, which has high selectivity when not saponified and preferentially complexes iron ions to form organic complexes: ; Due to its higher charge density, iron ions have a strong binding ability with P204 and are preferentially extracted into the organic phase, while most of the aluminum ions, copper ions, and manganese ions remain in the aqueous phase.

[0019] In the aluminum extraction step, P204 is saponified into the corresponding phosphate by partial reaction with alkali solution (such as NaOH or KOH). The saponified P204 has a higher affinity for aluminum ions while avoiding excessive extraction of other metals; saponification reaction: ; Aluminum extraction reaction:

[0020] Control pH 2.5-3.5: Within this pH range, Al³⁺ can be effectively extracted, while Cu²⁺ and Mn²⁺ remain in the aqueous phase, reducing co-extraction.

[0021] During the washing step, the weakly acidic conditions can transfer the entrained Cu²⁺ and Mn²⁺ from the organic phase to the aqueous phase, while Al³⁺ remains stably in the organic phase; ; ; After washing, the organic phase mainly contains Al³⁺, and other entrained metal ions are in the washing liquid for subsequent treatment.

[0022] In the stripping regeneration step, the washed organic phase is stripped with 4-6N hydrochloric acid to desorb Fe³⁺ and Al³⁺ from the organic phase to obtain a mixed solution of ferric chloride and aluminum chloride. The strong acid can destroy the complex of Fe³⁺ and Al³⁺ with P204 and transfer the metal ions to the aqueous phase: ; ; The stripping solution obtained is a mixture of ferric chloride and aluminum chloride, which can be directly used for sewage treatment without further recovery. The regenerated organic phase can be recycled for the next round of extraction after being washed with water to remove residual acid.

[0023] Overview of process parameters: step Raw material ratio Process parameters Critical Control Points Iron Extract Blank P204: leachate=1-2:1 3-stage countercurrent, 25-50℃, PH1.5-2.0 Fe³⁺ is preferentially extracted, and impurities are reduced Aluminum Extraction Saponification P204: Iron extraction liquid = 2-4:1 8-10 level countercurrent, 25-40℃, PH2.5-3.5 Reduce the co-extraction of Cu²⁺ and Mn²⁺ washing Dilute acid: organic phase = 1.5-2:1 6-stage countercurrent, 20-30℃ Remove entrained valuable metals and retain Al³⁺ Stripping Hydrochloric acid: organic phase = 1.5:1 2-3 level countercurrent, 25-30℃ Complete desorption of Fe³⁺, Al³⁺, organic phase regeneration

[0024] The following are examples and comparative examples of the present application:

[0025] Embodiment 1:

[0026] Ingredients of leachate: Ingredients of leachate: 1.38 g / L, 8.13 g / L, 0.6 g / L, 0.4g / L, here The concentration is the concentration of other valuable metals and.

[0027] Iron extraction parameters: temperature 25°C (normal temperature), three-stage countercurrent extraction; PH1.5-2.0; Extraction for the first time: P204: leachate volume ratio = 2:1, time 4 minutes and 30 seconds; Extraction for the second time: P204: leachate volume ratio = 2:1, time 5 minutes; Extraction for the third time: P204: extract volume ratio = 1:1, time 5 minutes and 30 seconds; After iron extraction and The remaining 0.0097g / L and 7.52g / L respectively, 0.6 g / L, 0.4g / L.

[0028] Aluminum extraction parameters: temperature 25°C (normal temperature), 8-10 level countercurrent extraction; PH2.5-3.5; The P204 with 20% saponification and 40% saponification was used for countercurrent extraction. After 4 extractions with 20% saponified P204, each time for 2 minutes, the liquid after iron and aluminum extraction and The remaining values ​​were 0.001 g / L and 0.44 g / L respectively; 0.586 g / L, 0.395 g / L After 40% saponified P204 extractions, each time for 3 minutes and 30 seconds, the liquid after iron and aluminum extraction and The remaining 0.001g / L and 0.0036g / L respectively, 0.506 g / L, 0.319 g / L.

[0029] Washing parameters: 6-stage countercurrent, temperature 25°C (normal temperature), After the aluminum-extracted organic phase is washed with 6-stage countercurrent washing with dilute acid, the ion contents in the dilute acid are: 0.001g / L, 0.002 g / L, 0.08 g / L, 0.072 g / L; Stripping parameters: temperature 25°C (normal temperature), 2-3 levels of countercurrent; The iron-extracted organic phase and the aluminum-extracted organic phase are stripped with 4-6N hydrochloric acid, and the main components of the stripping solution obtained are ferric chloride, aluminum chloride and an organic phase.

[0030] Embodiment 2:

[0031] Ingredients of leachate: Ingredients of leachate: 1.38 g / L, 8.13 g / L, 0.6 g / L, 0.4g / L, here The concentration is the concentration of other valuable metals and.

[0032] Iron extraction parameters: temperature 50°C, three-stage countercurrent extraction; PH 1.5-2.0; Extraction for the first time: P204: leachate volume ratio = 2:1, time 3 minutes; Extraction for the second time: P204: extract volume ratio = 2:1, time 2 minutes and 40 seconds; Extraction for the third time: P204: extract volume ratio = 1:1, time 2 minutes and 20 seconds; After iron extraction and The remaining 0.0015g / L and 4.76g / L respectively, 0.6 g / L, 0.4g / L.

[0033] Aluminum extraction parameters: temperature 25°C (normal temperature), 8-10 level countercurrent extraction; PH2.5-3.5; The P204 with 20% saponification and 40% saponification was used for countercurrent extraction. After 4 extractions with 20% saponified P204, each time for 2 minutes, the liquid after iron and aluminum extraction and The remaining values ​​were 0.001 g / L and 0.13 g / L respectively; 0.556 g / L, 0.375 g / L After 40% saponified P204 extractions, each time for 3 minutes and 30 seconds, the liquid after iron and aluminum extraction and The remaining 0.001g / L and 0.0012g / L respectively, 0.486 g / L, 0.301 g / L.

[0034] Washing parameters: 6-stage countercurrent, temperature 25°C (normal temperature), After the aluminum-extracted organic phase is washed with 6-stage countercurrent washing with dilute acid, the ion contents in the dilute acid are: 0.001g / L, 0.002 g / L, 0.095 g / L, 0.082 g / L; Stripping parameters: temperature 25°C (normal temperature), 2-3 levels of countercurrent; The iron-extracted organic phase and the aluminum-extracted organic phase are stripped with 4-6N hydrochloric acid, and the main components of the stripping solution obtained are ferric chloride, aluminum chloride and an organic phase.

[0035] According to Examples 1 and 2, increasing the temperature during the extraction of iron and aluminum can speed up the extraction of iron and aluminum.

[0036] Comparative Example 1: The difference from Example 1 is that the unsaponified concentration of P204 in the iron extraction step is 20%, and other conditions remain unchanged, and the result is The removal rate is only 92%; Comparative Example 2: The difference from Example 1 is that the P204 saponified aluminum in the aluminum extraction step is 50%, and other conditions remain unchanged. The removal rate was 93%, and the organic phase and Increased concentration; Comparative Example 3: The difference from Example 2 is that the pH of the aluminum extraction outlet is 4, and other conditions remain unchanged. and Concentration increased by 20%; Comparative Example 4: The difference from Example 2 is that the hydrochloric acid concentration in the stripping regeneration step is 3N, and other conditions remain unchanged, and the result is and The desorption rate is 85%, resulting in incomplete regeneration of the organic phase, decreased activity of P204, reduced extraction efficiency of the incompletely desorbed organic phase in subsequent extractions, and possible accumulation of impurities with long-term use.

[0037] Through the experimental comparison of Examples 1 and 2 with Comparative Examples 1-4, it can be concluded that the optimized process parameters of Example 1 have significant advantages in metal recovery rate, product purity, impurity control, process stability and environmental protection; strong process stability: the optimized pH, saponification rate and hydrochloric acid concentration significantly improve the process stability, which is suitable for long-term industrial applications; good environmental economy: the optimized process reduces the consumption of extractants, acids, alkalis and water, and at the same time, the type of waste liquid is single and the treatment cost is low.

[0038] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0039] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A P204 extraction and aluminum removal method for recycling waste battery materials, characterized in that: The following steps are involved: Iron extraction: The ternary black powder leachate was subjected to three-stage countercurrent extraction at a ratio of 1:1 to blank P204 to obtain an iron-extracted liquid and an iron-extracted organic phase; Aluminum extraction: The iron-extracted liquid and the saponified P204 with a saponification rate of 20%-40% are mixed in 8-10 stages of countercurrent to extract aluminum, and the iron-extracted aluminum liquid and the aluminum-extracted organic phase are obtained; Washing: The aluminum-loaded organic phase carries some copper and manganese, and enters the stripping section after 6 levels of dilute acid washing; Stripping regeneration: After washing, the organic phase is stripped of iron and aluminum with 4-6N hydrochloric acid; after stripping, the organic phase is washed with water and the residual acid is returned to the front end for extraction.

2. The P204 extraction and aluminum removal method for recycling waste battery materials according to claim 1 is characterized in that: In the iron extraction step, the volume ratios of the leaching solution and the blank P204 in the three-stage countercurrent extraction are respectively: 2:1 for the first time, 2:1 for the second time and 1:1 for the third time.

3. The P204 extraction and aluminum removal method for recycling waste battery materials according to claim 1 is characterized in that: The extraction temperature of the iron extraction step is controlled at 25-50°C.

4. The P204 extraction and aluminum removal method for recycling waste battery materials according to claim 1 is characterized in that: Control the outlet pH of the liquid after iron and aluminum extraction to 2.5-3.

5.

5. The P204 extraction and aluminum removal method for recycling waste battery materials according to claim 1 is characterized in that: The volume ratio of the iron-extracted liquid to the saponified P204 with a saponification rate of 20%-40% is 4:

1.

6. The P204 extraction and aluminum removal method for recycling waste battery materials according to claim 1 is characterized in that: After washing, the mixture needs to be allowed to stand for stratification, the washing liquid and the organic phase need to be separated, and the residual organic phase needs to be recovered using 4-6N hydrochloric acid.

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