KR102137174B1 - Critical metal recovering method from exhausted lithium ion batteries - Google Patents

Abstract

The present invention relates to a method for recovering precious metals included in a cathode of a waste lithium ion battery and, more specifically, to a method for recovering precious metals, comprising the steps of: inputting cathode powder in water to perform primary leaching (S1); adding a carbonate to a primary leachate produced by the primary leaching to acquire a primary precipitate and to recover nickel (S2); adding an organic acid to a primary leaching residue, from which the primary precipitate has been removed, to acquire an organic acid leachate containing cobalt (S3); adding an immiscible medium to the organic acid leachate to acquire an immiscible phased liquid containing the cobalt (S4); and adding an aqueous medium to the immiscible phased liquid and performing stripping to recover the cobalt (S5), thereby recovering the precious metals such as nickel and cobalt from a depleted battery.

Description

{Critical metal recovering method from exhausted lithium ion batteries}

The present invention relates to a method for recovering important metals from a waste lithium ion battery.

Lithium ion batteries (hereinafter referred to as LiB) are classified as rechargeable batteries in which lithium (Li ⁻ ) ions move from the negative electrode to the positive electrode during discharge and reversely during charging. In addition, the Co metal compound assists electrons to move during the charge-discharge process.

In recent decades, the specific energy density of LiB is 100-265 Wh/kg; Specific power 250-340 W/kg; Due to technical characteristics such as circulating life 400-1200, LiB has been applied in various modern electrical and electronic devices. Mobile phones, laptops, electric and hybrid vehicles, auxiliary batteries and off-grid renewable energy (for general storage purposes) are the main applications of LiB.

As the use of LiB increases as described above, a large amount of waste is generated after the life cycle of LiB is completed and discharged. When LiB is buried and treated, electrolytes and metal compounds are slowly leached from the buried LiB, which can seriously increase contamination, which can be a serious threat to soil and water flow. Accordingly, there is a need for a method for treating a large amount of discharged LiB continuously generated in terms of environmental sustainability.

On the other hand, discharged LiB contains several times more important metals such as lithium (Li) and cobalt (Co) compared to natural minerals. In addition, natural minerals containing Li and Co often contain more impurities than LiB cathode powder. Efficient recycling of LiB, therefore, can not only mitigate potential risks to the environment, but also deplete global critical metal resources.

There is increasing interest in developing an efficient technology for recovering metal from such discharged batteries. The recovery approach mainly requires mechanical pretreatment in addition to subsequent pyro- and/or wet smelting operations (US Pat. 8616475; CN101988156; CN 1601805A; US 20130302226A1; WO 2017/118955 A1; WO 2017/006209 A1). Mechanical treatment has been maintained in a fairly simple manner and is commonly used for the physical separation of iron, aluminum, copper and plastic from cathode materials. International patent publication WO 2017/006209 A1 discloses separation and recovery of all metal compounds by a wet grinding-heat treatment-density separation method. Wet grinding requires sophisticated equipment, and a large amount of water can be consumed, such as the process disclosed in International Patent Publication WO 2017/118955 A1, which can lead to problems on a larger scale. US Pat. No. 8616475 discloses a process for the recovery of copper, aluminum, carbon and cathode materials, but has been found to be ineffective due to limited and low purity metal recovery. In addition, the pH-sensitive process disclosed in CN 101988156 can lead to incomplete metal recovery with a pH deviation pattern. The method disclosed by CN 1601805A has a concern that, due to the corrosive and dynamic utterance of hydrogen fluoride, the purity is also lowered.

In addition, most of the processes known in the art for applying smelters require high energy, while wet smelting operations use large quantities of harmful chemicals. Both processes produce toxic gases and harmful emissions. Sulfuric acid is used as the most common medium, but releases 5.4 × 10 ⁵ kg of CO ₂ , 1.365 × 10 ³ kg of SO ₂ , 9.8 × 10 kg of ethane and 1.3 × 10 ² kg of phosphate for every 100 tonnes of discharged LiB. There is a problem. These hazardous emissions are undesirable in terms of process sustainability. This has the advantage that the use of organic acids instead of mineral acids is increasingly being studied today, that organic acids are biodegradable, free of harmful gases and can be discharged directly into the water stream.

Therefore, there is a need for an eco-friendly and effective method for efficiently recovering the critical metal from the discharged LiB along with the purity of the metal compound.

An object of the present invention is to provide a method for recovering important metals from a discharged lithium ion battery.

However, the technical problem to be achieved by the present invention is not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

The present invention provides a method for recovering important metals from a cathode of a waste lithium ion battery comprising the following steps:

A step of first leaching the cathode powder into water (S1);

Recovering nickel by obtaining a primary precipitate by adding carbonate to the primary leachate formed by the primary leaching (S2);

Obtaining an organic acid leaching liquid containing cobalt by adding an organic acid to the primary leaching residue from which the primary precipitate is removed (S3);

Adding an immiscible medium to the organic acid leachate to obtain a liquid immiscible with cobalt (S4); And

A step of recovering cobalt by stripping by adding an aqueous medium to the immiscible liquid (S5).

In one embodiment of the present invention, after the first leaching in the step S1, characterized in that it further comprises the step of treating the activated carbon (S1').

In another embodiment of the present invention, the first leaching of the step S1 is characterized in that it is performed by stirring at a temperature of 60 to 120 ℃ for 200 minutes to 300 minutes.

In another embodiment of the present invention, the organic acid in the S3 step has a concentration of 1 to 5 M, and the organic acid is ascorbic acid (ascorbic acid), citric acid (citric acid), oxalic acid (oxalic acid), malonic acid ( malonic acid, malic acid, tartaric acid, acetic acid, fumaric acid, lactic acid, formic acid, propionic acid, butyric acid ), iminodiacetic acid, glyoxylic acid, lactic acid, maleic acid, acrylic acid, valeric acid, pivalic acid, n-hexanoic acid, t-octanoic acid, 2-ethyl-hexanoic acid, neodecanoic acid, lauric acid, stearic acid It is characterized by at least one member selected from the group consisting of (stearic acid), oleic acid, naphthenic acid, dodecanoic acid and linoleic acid.

In another embodiment of the present invention, the step S3 is characterized in that it is performed by stirring at a temperature of 50 ℃ to 90 ℃ for 60 minutes to 150 minutes.

In another embodiment of the present invention, the immiscible medium of the step S4 is characterized in that the organic phosphate ester.

In another embodiment of the present invention, the step S4 is characterized in that it is performed in a cumulative extraction method.

In another embodiment of the invention, the method after step S5,

Re-extracting by adding an organic acid solvent having a long carbon chain to the liquid of the aqueous phase stripped in step S5 (S6); And

A second stripping step (S7) by adding an acidic solution to the liquid on the organic acid solvent may be further included.

In another embodiment of the present invention, the organic acid solvent having a long carbon chain is di-2-(ethylhexyl)phosphonic acid, bis/2,4,4-trimethylpentyl/ Phosphonic acid (bis/2,4,4-trimethylpentyl/phosphinic acid), 2-ethylhexylphosphonic mono-2-ethylhexyl ester, bis2,4,4-trimethyl It is characterized in that it is selected from one or more of the group consisting of pentylphosphonic acid (Bis (2,4,4-Trimethylpentyl) phosphonic acid) and neodecanoic acid.

The present invention relates to a novel process for recovering important metals from a discharged lithium ion battery (LiB), and more particularly, to a novel process for recovering lithium and cobalt from the cathode powder of LiB. The process has excellent advantages from an economical point of view, showing that it is environmentally friendly, efficient, and has a high metal recovery rate using water and organic acids, unlike the conventional process that produced secondary pollutants.

1 schematically shows a method for recovering important metals of the present invention.
Figure 2 shows the XRD pattern of the cathode powder used in Examples of the present invention.
Figure 3 shows the results confirming the leaching behavior of LiCoO ₂ cathode powder according to temperature.
Figure 4 shows the results of checking the yield of lithium and cobalt in the washing solution washed with leach and hot water in Example 4.
Figure 5 shows the result of confirming the XRD pattern of the precipitate obtained after adding a carbonate salt to the lithium-containing leach.
Figure 6 shows the results confirming the cobalt leaching behavior of the lithium-removed residue of the cathode powder according to the concentration of ascorbic acid.
Figure 7 shows the results confirming the cobalt leaching behavior of the lithium-removed residue of the cathode powder according to temperature and time conditions when treating 2M ascorbic acid.
Figure 8 shows the results confirming the cobalt extraction behavior according to the pH concentration.
Figure 9 shows the results of checking the extraction efficiency and cumulative efficiency in each step according to the number of extraction (step).
Figure 10 shows the results confirming the behavior of the stepwise stripping of cobalt contained in the organic phosphate ester using water (O:A, 2:1).
11 shows the results confirming the behavior of extracting cobalt from a stripped liquid treated with 0.2 mol bis/2,4,4-trimethyl pentyl/phosphinic acid according to the equilibrium pH (O:A, 1:2).
FIG. 12 shows the result of confirming the XRD pattern of CoSO4.xH2O, a crystalline product obtained by treating sulfuric acid with the stripped liquid.

The present inventors researched a method of recovering lithium and cobalt, which are important metals, from the cathode of a discharged waste lithium ion battery containing LiCoO ₂ for resource recycling, and released secondary pollutants with high metal recovery rate. An eco-friendly wet processing method that is not developed was developed to complete the present invention. That is, the present invention provides a method for recovering lithium (Li) and cobalt (Co) from the cathode powder of the spent lithium ion battery that has reached the end of its life.

The method of the present invention is schematically described and described in FIG. 1 with a combination of physical and chemical treatments for selectively extracting important metals from cathode powder collected from discharged LiB. The method may largely include selective dissolution of lithium in water (hereinafter LL-1) and selective dissolution of cobalt in organic acid (hereinafter LL-2). The solution containing metal as described above can be further treated for metal recovery; LL-1 undergoes precipitation of Li as a carbonate, while LL-2 extracts Co using an immiscible organophosphorous solvent. The metal recovered by the method of the present invention is obtained with a purity of at least about 99%.

More specifically, the present invention provides a method for recovering important metals from a cathode of a waste lithium ion battery, comprising the following steps:

A step of first leaching the cathode powder into water (S1);

Recovering nickel by obtaining a primary precipitate by adding carbonate to the primary leachate formed by the primary leaching (S2);

Obtaining an organic acid leaching liquid containing cobalt by adding an organic acid to the primary leaching residue from which the primary precipitate is removed (S3);

Adding an immiscible medium to the organic acid leachate to obtain a liquid immiscible with cobalt (S4); And

A step of recovering cobalt by stripping by adding an aqueous medium to the immiscible liquid (S5).

Below. The method of the present invention will be described in more detail step by step.

[Step S1]

Step S1 of the present invention is a step in which the cathode powder is first leached into water. The cathode powder is obtained from a discharged battery, and can be used without limitation as long as it is obtained from a discharged battery. Preferably, after disassembling the cell phone battery, the cathode is collected and heat treated to obtain a powder form. May be The cathode powder is Li, 3-10 wt.%; Co, 25-30 wt.%; Cu, 0.010 ~ 0.020 wt.%, and Ni, may be to include 0.05 to 0.2 wt.%, but is not limited thereto.

After the first leaching in step S1, the step of treating the activated carbon (S1') may be further included.

After the first leaching, the solid slurry component remaining by filtration can be washed with an appropriate solvent (preferably water). The washing solution may be added to the primary leach solution, and the recovery rate of lithium may be higher when the washing solution is added.

The primary leaching of step S1 is preferably performed by stirring at a temperature of 60 to 120°C for 200 to 300 minutes, more preferably, at a temperature of 80 to 90°C for 220 to 260 minutes, but is not limited thereto. It is not.

[Step S2]

In the present invention, step S2 is a step of recovering nickel by adding carbonate to the primary leach produced by leaching the cathode powder in step S1, thereby obtaining a primary precipitate.

More specifically, after the leaching of step S1 is performed, a solid precipitate is added to the resulting leachate, excluding the solid slurry, to obtain a primary precipitate containing nickel, the carbonate being an alkali metal carbonate, preferably Lithium can be recovered using sodium carbonate.

[Step S3]

In the present invention, step S3 is a step of obtaining an organic acid leaching liquid by adding an organic acid to the remaining leaching residue after performing the primary leaching, wherein the organic acid leaching liquid contains cobalt.

The organic acid preferably has a concentration of 1 to 5 M, the organic acid is ascorbic acid (ascorbic acid), citric acid (citric acid), oxalic acid (oxalic acid), malonic acid (malonic acid), malic acid (malic acid), Tartaric acid, acetic acid, fumaric acid, lactic acid, formic acid, propionic acid, butyric acid, iminodiacetic acid, Glyoxylic acid, lactic acid, maleic acid, acrylic acid, valeric acid, pivalic acid, n-hexanoic acid, t -Octanoic acid, 2-ethyl-hexanoic acid, neodecanoic acid, lauric acid, stearic acid, oleic acid , Naphthenic acid, dodecanoic acid, and linoleic acid. Preferably, ascorbic acid may be used, but is not limited thereto.

In the step S3, leaching with an organic acid may be performed by stirring at a temperature of 50°C to 90°C for 60 minutes to 150 minutes, preferably 60 to 80°C for 100 to 130 minutes at a speed of 300 to 600 rpm. It is preferable to perform at a temperature in terms of leaching efficiency.

[Step S4]

Step S4 is a step of adding an immiscible medium to the organic acid leachate, and extracting cobalt contained in the organic acid leachate by treating the immiscible medium.

The immiscible medium of the step S4 is an organic phosphoric acid ester, and the organic phosphoric acid ester may be at least one selected from the group consisting of trioctylphosphine and tributyl phosphate, and preferably tributyl phosphate. The step S4 is preferably equilibrated such that the equilibrium pH is 5 to 7, and it is performed by a cumulative extraction method, and may be repeatedly performed an extraction process two or more times.

[Step S5]

Step S5 is a step of stripping by adding an aqueous medium to the immiscible liquid formed by step S4. By step S5, cobalt contained in the immiscible liquid is extracted into an aqueous medium. The stripping may be performed repeatedly five or more times, and the immiscible medium may be regenerated in a process repeatedly performed. The immiscible medium can be regenerated and used again in step S4.

[Step S6]

Step S6 is a re-extraction step of adding an organic acid solvent having a long carbon chain to the liquid of the aqueous phase containing cobalt produced by stripping in step S5. The organic acid solvent having a long carbon chain is di-2-(2-ethylhexyl) phosphoric acid, bis/2,4,4-trimethylpentyl/phosphonic acid (bis/2,4, 4-trimethylpentyl/phosphinic acid), 2-ethylhexylphosphonic mono-2-ethylhexyl ester; Bis 2,4,4-trimethylpentyl phosphonic acid (Bis (2,4,4-Trimethylpentyl) phosphonic acid) and neodecanoic acid (neodecanoic acid) may be selected from the group consisting of, but is not limited thereto.

The liquid of the aqueous phase and the organic acid solvent (O) having a long carbon chain and the liquid of the aqueous phase (A) may be contacted in an organic-aqueous phase ratio of 1:0.5-3, and preferably maintain an equilibrium pH 3-6 While the O:A ratio of 1:1.5~2.5.

[Step S7]

Step S7 is a step of secondary stripping by adding an acidic solution to cobalt contained in the organic acid solvent having a long carbon chain in step S6. The acidic solution may be a 0.5 to 1.5 M sulfuric acid solution, but is not limited thereto. The liquid (O) and the acidic solution (A) in the organic acid solvent phase may be mixed at a ratio of 3 to 8:1 O:A.

After mixing, the cobalt contained in the sulfuric acid solution can be obtained by a simple electrowinning method, evaporation-crystallization treatment, etc., and the collection can be performed by selecting a conventional method.

Accordingly, according to the method of the present invention, it is possible to selectively/independently easily recover nickel and cobalt, which are important metals remaining in the discharged battery. The recovered important metal can be reused.

Hereinafter, the present invention will be described in more detail through examples. These examples are only for explaining the present invention more specifically, it will be apparent to those skilled in the art that the scope of the present invention is not limited by these examples.

[Example]

Example 1. Preparation of cathode powder

A discharged cell phone battery was obtained, manually dismantled and immersed in brine for 48 hours. Copper and aluminum foils were collected separately by removing the plastic part and spreading the positive and negative electrodes. The aluminum foil was heat treated at 500° C. for 1 hour in muffle furnace to separate the black cathode powder.

The obtained cathode material in powder form was homogenized and analyzed by Li, 4.83 wt.%; Co, 28.4 wt.%; It was confirmed to contain Cu, 0.014 wt.%, and Ni, 0.13 wt.%. Physical properties of the cathode powder were analyzed using X-ray diffraction (XRD) equipment to confirm the presence of the LiCoO ₂ phase (FIG. 2 ). Therefore, it can be seen that the important metals lithium and cobalt can be recovered from the powder.

Example 2. Confirmation of leaching yield of cathode powder under ambient temperature conditions

25 g of the cathode powder was placed in a 1 L glass beaker and stirred at ambient temperature (30° C.) for 240 minutes at a rate of 400 rpm using a magnetic paddle and leached into 500 mL of deionized water. After the equilibration time was completed, the slurry was filtered under high temperature conditions, and it was confirmed that ~14% by weight of lithium was contained in the obtained leach, but no dissolution of Co was found.

Example 3. Confirmation of leaching yield of cathode powder at high temperature conditions

25 g of the cathode powder was placed in a 1 L glass beaker, stirred at a temperature of 400° C. or higher and 80° C. for 240 minutes at a rate of 400 rpm with a magnetic paddle, and leached into 500 mL of deionized water. Upon completion of the equilibration time, the slurry was filtered under high temperature conditions, and the leach solution was analyzed to contain ~82% by weight of Li. The analysis results of the leach solution according to the temperature change are shown in FIG. 3.

Example 4. Confirmation of leaching yield of cathode powder by washing

25 g of the cathode powder was leached into 500 mL of deionized water at an elevated temperature of 90° C. and stirring was performed at a rate of 400 rpm for 240 minutes. After filtering the slurry under high temperature conditions, the residual layer was washed 4 times with a total of 100 mL of washing water at 80°C.

The washing solution was mixed with the leach solution, and the mixture was analyzed to obtain a total of 96% by weight or more of Li, while the Co concentration was less than 5 mg/L. The individual recovery rates of the critical metals from the washing and leach solutions are shown in FIG. 4.

Example 5. Obtaining lithium precipitate from filtrate

The filtrate obtained from Example 4 (a solution in which the washing solution and the leach solution was mixed) was added with 1.5 times more sodium carbonate based on the molar amount of Li, and slowly precipitated at 200 rpm and precipitated activated carbon for 5 minutes (average particle size ~ 200 mesh).

When the activated carbon treatment was completed, the filtrate was heated at a boiling temperature (100° C.), and a carbonate salt was added while stirring at 300 rpm for 180 minutes. The slurry was heat filtered, washed with boiling water, and then dried in a hot air oven at 80° C. overnight to obtain a precipitate. 5 shows the XRD pattern of the precipitate, and it was confirmed from the pattern that the precipitate was lithium carbonate (Li ₂ CO ₃ ).

Example 6. Analysis of leaching of cobalt

In Example 6, a leaching study of Co from the leaching residue produced in Example 4 was performed. While stirring the leach residue at 60 °C for 60 minutes at a rate of 400 rpm, ascorbic acid solution (0.5 mol / L, 0.8 mol / L, 1.2 mol / L) with a concentration range of 0.5 ~ 2.5 mol / L as an organic acid , 1.6 mol/L, 2.0 mol/L, 2.5 mol/L) to obtain 10 g leaching residue in 500 mL solution.

Immediately after the leaching was completed, the slurry was filtered to collect the leaching liquid, washed with 50 mL of warm water (60° C.), and a leaching liquid of an ascorbic acid solution was obtained. As shown in FIG. 6, the leaching efficiency was 86.3%, and it was confirmed that it is suitable to use ascorbic acid having a concentration of 2.0 mol/L or more for quantitative leaching of Co.

Example 7. Confirmation of cobalt leaching efficiency according to leaching temperature and time conditions

In the present Example 7, the leaching residue generated in Example 4 was checked for the leaching behavior of Co according to the leaching temperature. The leach residue was treated with 2 mol/L ascorbic acid with an organic acid solution while stirring at a temperature of 60 rpm to 400° C. at a rate of 400 rpm for 120 minutes to obtain 10 g of water leach residue from a 500 mL solution.

Immediately after the leaching was completed, the slurry was filtered to collect the leaching liquid, washed with 50 mL of hot water (60°C), and a leaching liquid of an ascorbate solution was obtained. As shown in Figure 7, it can be seen that it is desirable to leach at 75 °C for 90 minutes. Interestingly, at temperatures above 90°C, the leaching efficiency was rather low. This indicates that the dehydroascorbic acid (DHAA) can be hydrolyzed to 2,3-diketogluconic acid by hydrolysis of the lactone ring in DHAA at a temperature of 80°C or higher.

Example 8. Cobalt extraction with immiscible medium

The organic acid leachate of the aqueous phase produced in Example 7 was used for Co extraction using an immiscible medium composed of an organic phosphate ester. 100 mL of the leachate of the aqueous phase was contacted with 100 mL of an organic phosphate ester in a 250 mL glass separation funnel (organic acid ester and organic acid leachate ratio of the aqueous phase (O:A), 1:1). Equilibrium time of 5 to 10 minutes was obtained at ambient temperature (~30℃).

To settle both the aqueous and organic phases, the fully equilibrated solution was separated by providing a settling time of 10 minutes. The aqueous stream precipitated at the bottom called'raffinate' was collected and diluted using a 5% by volume HCl solution, and then Co concentration was analyzed. The extraction efficiency determined at different equilibrium pH is shown in Figure 8.

As shown in Fig. 8, when the equilibrium pH was 6.0 pH, the best extraction efficiency was shown.

Example 9. Cobalt extraction efficiency confirmation according to the extraction method

The leach solution produced in Example 7 was used to extract Co with an organic phosphoric acid ester. Using 100 mL of organic phosphate ester in 100 mL of the leach solution, put it in a 250 mL glass separation funnel, and react at equilibrium pH 6.0 showing the highest extraction efficiency identified in Example 8 for 5 to 10 minutes and at room temperature (~30°C). Ordered.

After each reaction, the two phases were allowed to equilibrate to each other three times in succession, and the equilibrated solutions were separated after having a desired settling time of 10 minutes. The raffinate recovered at the bottom was analyzed to determine the Co concentration therein, and the cumulative extraction efficiency was calculated as shown in FIG. 9. From the results of FIG. 9, it can be seen that the extraction efficiency is increased by performing the cumulative extraction by repeating three times, and thus the extraction efficiency is increased.

Example 10. Stripping treatment of cobalt-containing organic solvent

The organic solvent containing Co of Example 9 was stripped with half the volume of 50 mL of water with respect to the organic solvent, and equilibrated for 10 minutes at room temperature of ~30°C.

When equilibration and sedimentation of 10 minutes each were completed, the stripped aqueous solution was obtained to analyze the metal concentration in the solution. As shown in Fig. 10, Co was gradually stripped to become an aqueous solution through stripping repeated 5 times. The organophosphate solvent was regenerated as Co moved to the aqueous solution. The regenerated organophosphate solvent can be used again for the purpose of extracting cobalt as in Example 9.

Example 11.Re-extraction of cobalt using stripped liquid

In Example 11, the stripped liquid obtained in Example 10 was mixed with an organic acid solvent, which is preferably a long carbon chain acid extractant, to re-extract the metal.

In this example, 0.2 moles of phosphinic acid (diluted with distilled kerosene) at a concentration higher than the stoichiometric requirement is stripped with a ratio other than the organic-aqueous phase ratio described above, 1:2 (O:A). Contact with. The extraction results according to the equilibrium pH conditions are shown in FIG. 11 while maintaining the desired equilibrium pH (range of 3.0 to 6.0). As shown in Fig. 11, the extraction efficiency of cobalt increased as the pH increased.

Example 12. Obtaining cobalt from stripping liquid

As in Example 11, phosphinic acid was mixed with 250 ml of the stripping liquid obtained in Example 10 with 125 ml of organic solvent to equilibrate for 5 minutes at an equilibrium pH of 5.5, and then to confirm the concentration of Co in the solution. Both phases were settled in a 500 ml volume separating funnel before sampling the raffinate. The loaded organic solvent was stripped with 1.0M sulfuric acid at a high O:A of 5:1 to obtain a sulfuric acid solution containing Co in a high concentration. From this solution, Co can be electrolyzed at the cathode, or can be obtained after a simple evaporation-crystallization step as a crystal product.

For the crystalline product, it was observed that the product purity was >99%. The XRD pattern of the high purity CoSO4.xH2O product is shown in Figure 12.

The preferred embodiments of the present invention have been described in detail above, but the rights of the present invention are not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

Claims (9)

A method of recovering important metals from a cathode of a waste lithium ion battery comprising the following steps:
A step of first leaching the cathode powder into water (S1);
Recovering nickel by obtaining a primary precipitate by adding carbonate to the primary leachate formed by the primary leaching (S2);
Obtaining an organic acid leaching liquid containing cobalt by adding an organic acid to the primary leaching residue from which the primary precipitate is removed (S3);
Adding an immiscible medium to the organic acid leachate to obtain a liquid immiscible with cobalt (S4); And
A step of recovering cobalt by stripping by adding an aqueous medium to the immiscible liquid (S5). According to claim 1,
After the first leaching in the step S1, characterized in that it further comprises the step of treating the activated carbon (S1'), a method for recovering important metals from the cathode of the waste lithium ion battery.
According to claim 1,
The first leaching of the step S1 is characterized in that is performed by stirring for 200 to 300 minutes at a temperature of 60 to 120 ℃, a method for recovering important metals from the cathode of the waste lithium ion battery.
According to claim 1,
The organic acid in the step S3 has a concentration of 1 to 5 M, and the organic acid is ascorbic acid, citric acid, oxalic acid, malonic acid, malic acid, tartaric acid, acetic acid, fumaric acid, lactic acid, formic acid, propionic acid, butyric acid, iminodiacetic acid, glycerol Oxylic acid, lactic acid, maleic acid, acrylic acid, valeric acid, pivalic acid, n-hexanoic acid, t-octanoic acid, 2-ethyl-hexanoic acid, neodecanoic acid, lauric acid, stearic acid, oleic acid, naphthenic acid, dodecanoic acid And at least one selected from the group consisting of linoleic acid. A method for recovering important metals from a cathode of a waste lithium ion battery.
According to claim 1,
The step S3 is characterized in that is performed by stirring at a temperature of 50 ℃ to 90 ℃ for 60 minutes to 150 minutes, a method for recovering important metals from the cathode of the waste lithium ion battery.
According to claim 1,
A method for recovering an important metal from the cathode of a waste lithium ion battery, characterized in that the immiscible medium of the step S4 is an organic phosphate ester.
According to claim 1,
The step S4 is characterized in that is performed by a cumulative extraction method, a method for recovering important metals from the cathode of the waste lithium ion battery.
According to claim 1,
The method after step S5,
Re-extraction step of adding an organic acid solvent to the liquid of the aqueous phase stripped in step S5 (S6); And
Secondary stripping step (S7) by adding an acidic solution to the liquid on the organic acid solvent, and
The organic acid solvent of step S6 is di-(2-ethylhexyl)phosphonic acid, bis/2,4,4-trimethylpentyl/phosphonic acid, 2-ethylhexylphosphonic mono-2-ethylhexyl ester, bis2,4 ,4-Trimethylpentylphosphonic acid and neodecanoic acid, characterized in that one or more selected from the group consisting of, a method for recovering important metals from the cathode of a waste lithium ion battery.
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