CN117144140A - A method for extracting nickel from waste ternary lithium-ion batteries - Google Patents

Abstract

The application relates to a recycling method of lithium ion batteries, in particular to a method for extracting nickel from waste ternary lithium ion batteries, which comprises the steps of preparing black powder of batteries into slurry, sequentially carrying out low-acid leaching and high-acid leaching to obtain a pre-impurity extraction liquid, sequentially carrying out a first extraction step and a second extraction step on the pre-impurity extraction liquid, mixing the pre-impurity extraction liquid with a third extractant solution containing saponified ions, extracting nickel ions into the third extractant solution, carrying out back extraction on the third extractant solution to obtain a refined nickel solution, and evaporating the refined nickel solution to obtain a nickel salt crystal product. The extraction method of the application has higher extraction rate for each element in the battery, and simultaneously reduces the extraction level and the consumption of the extractant, thereby effectively saving energy, saving cost and simultaneously reducing the requirements for equipment.

Description

A method for extracting nickel from waste ternary lithium-ion batteries

Technical field

The present invention relates to a recycling method of lithium-ion batteries, and in particular, to a method of extracting nickel from waste ternary lithium-ion batteries.

Background technique

As an efficient and reliable energy storage device, lithium-ion batteries play an important role in modern society. In particular, ternary lithium batteries are widely used in mobile communications, electric vehicles, energy storage systems and other fields due to their advantages such as high energy density, long life and low self-discharge rate.

However, with the popularity of ternary lithium batteries, the issue of battery recycling has also attracted increasing attention. Lithium-ion batteries contain a large number of valuable materials, such as cobalt, nickel and other elements. If these valuable materials can be recycled and reused, it can effectively reduce environmental pollution, reduce production costs, and be sustainable for the environment and resources. Utilization is crucial. Therefore, how to reuse these valuable materials has become one of the hot topics of current research.

At present, some effective methods have been proposed and applied for the recycling of lithium-ion batteries. Among them, physical methods, chemical methods and biological methods are commonly used recycling technologies.

Although existing recycling methods have achieved certain results, there are still some problems and shortcomings. First, some methods are less efficient at recycling specific elements and cannot achieve full recycling. For example, important elements such as cobalt and nickel can be mixed with other impurities during the recycling process, resulting in reduced recycling efficiency. Secondly, some methods will produce harmful waste or cause secondary pollution to the environment during the treatment process, such as waste liquid and waste disposal problems in chemical methods. In addition, the cost of some methods is high and not economically feasible, which limits their popularity in industrial applications.

In order to efficiently recycle valuable elements such as cobalt and nickel in lithium-ion batteries, further research and development of new recycling technologies are needed to solve the problems of existing methods and improve recycling efficiency and economy.

The patent with publication number CN109775766A discloses a method for rapid recovery of nickel and cobalt elements in ternary battery materials, including physical pretreatment steps, roasting and oxidation steps, acid leaching steps and filtration, extraction and purification steps. The roasting and oxidation steps can be retrieved through the vent. By connecting the exhaust equipment and adding sodium chloride solution in advance during the acid leaching step, the recovery method of nickel and cobalt elements from ternary batteries can be greatly simplified. Compared with the existing technology, this solution can realize multiple steps in one device. It can be completed at the same time, the process can be reduced by 30-40%, the time can be shortened by 50-60%, and the operation is simple, without the need for a large number of professional and technical personnel to operate, which can greatly reduce the operating threshold of nickel and cobalt element recycling enterprises, while ensuring the nickel and cobalt elements. When the recycling rate is high, the recycling efficiency can be greatly improved, which is conducive to the development of the ternary battery recycling industry, environmental protection and sustainable development.

The patent with publication number CN115771973A discloses a method for recovering nickel and cobalt from strongly acidic wastewater. The method for recovering nickel and cobalt specifically includes the following steps: (1) pretreatment; (2) D402 resin adsorption; (3) Washing and extracting cobalt: (4) Soaping treatment; (5) Washing and extracting cobalt; (6) Post-processing. The present invention sets up a suitable comprehensive wastewater flow rate and pretreats the resin, and uses extraction technology to prevent the formation of double salt crystals with high nickel and high ammonium, and carries out a unique multi-stage soap conversion reaction design, and finally makes the residual liquid 1 and The saponification liquid and wastewater from each workshop are comprehensively treated, and then the pretreated D402 resin is used to adsorb and remove weight. The cobalt in the load and the residual nickel-magnesium liquid are purified and then subjected to fractional distillation extraction and other designs to obtain battery-grade products. The entire process flow is mostly as follows Closed-circuit circulation, high reagent utilization rate, and high nickel and cobalt content.

Contents of the invention

The present invention is to overcome the shortcomings of the existing method of extracting cobalt, nickel and other elements from waste ternary lithium-ion batteries, which have low recycling rates and high impurity content in the recycled products, and provides a method for extracting cobalt, nickel and other elements from waste ternary lithium-ion batteries. Method for extracting nickel from ternary lithium-ion batteries.

In order to achieve the above-mentioned object of the invention, the present invention is implemented through the following technical solutions:

In the first aspect, the present invention first provides a method for extracting nickel from waste ternary lithium-ion batteries, which includes the following steps: (S.1) Discharging, dismantling, crushing, and sorting the waste ternary lithium-ion batteries in sequence. After selection and pyrolysis, the battery black powder material is obtained; (S.2) The battery black powder material is prepared into a slurry, and then sequentially undergoes low-acid leaching, high-acid leaching, copper removal and value adjustment processes to obtain impurity extraction pre-liquid;

(S.3) Mix the pre-extraction liquid with the first extractant solution containing the extraction agent P204 after nickel soap conversion and ether solvent, and perform the first extraction step to remove calcium, copper, zinc, aluminum, iron, and manganese metal ions to obtain a first extraction residue containing nickel, cobalt, and magnesium metal ions;

(S.4) Mix the first extraction raffinate with the second extractant solution containing the nickel soap-converted extractant P507 and the ketone solvent, perform the second extraction step, and extract cobalt ions and magnesium ions into the second In the extractant solution, a second extraction residue containing nickel ions is obtained;

(S.5) Mix the second extraction raffinate with the third extractant solution containing the saponified third extractant, extract nickel ions into the third extractant solution, and the third extractant solution is back-extracted Obtain refined nickel solution;

(S.6) Evaporate the refined nickel solution to obtain a nickel salt crystal product.

In the existing technology, when acid leaching and solvent extraction are used to extract nickel elements from ternary lithium-ion batteries, the impurity content in the nickel salt finally obtained is relatively high, so it is necessary to repeatedly extract the cobalt salt. Purification treatment leads to poor yield and economical efficiency of nickel element in the recovery process.

After testing, it was found that using existing technology, the impurities in the cobalt salt finally obtained are usually impurity metal ions such as calcium, copper, zinc, aluminum, iron, etc. Therefore, how to reduce the mixing of such metal ion impurities during the extraction process is what we must be resolved. The extraction agent currently used to extract impurity metal ions such as calcium, copper, zinc, aluminum, iron, etc. is usually extraction agent P204, which has a better extraction effect on these metal ions. However, during the process of extracting these impurity metal ions, extraction agent P204 It takes multiple extractions to achieve good extraction results, which is specifically reflected in the increase in extraction levels and the increase in extraction agent consumption.

In response to the above problems, the inventor of the present application accidentally discovered during the experiment that during the extraction process of impurity metal ions such as calcium, copper, zinc, aluminum, iron, etc., a certain amount of ether solvent is added to the extractant solution. , can effectively improve the extraction effect of the extraction agent P204 on impurity metal ions, specifically by reducing the number of extraction stages of the extraction agent for these impurities. In view of the above phenomenon, the inventor conducted certain research and found that the addition of ether solvent can play a certain coordination role on impurity metal ions such as calcium, copper, zinc, aluminum, iron, etc., thereby firstly coordinating with calcium, copper, zinc , aluminum, iron and other impurity metal ions are combined, and these impurity metal ions are introduced into the organic phase containing the first extraction agent and ether solvent. Since the coordination effect of ether solvents is not as good as that of extraction agent P204, impurity metal ions such as calcium, copper, zinc, aluminum, and iron can be transferred to extraction agent P204 in the organic phase, thereby effectively reducing the effect of extraction agent P204 on calcium , copper, zinc, aluminum, iron and other impurity metal ions coordination difficulty. This further improves the extraction effect of extraction agent P204 on impurity metal ions such as calcium, copper, zinc, aluminum, and iron in the impurity extraction liquid. And because the extraction agent P204 has poor coordination effect on nickel, cobalt, and magnesium metal ions, the extraction agent P204 will limit the extraction of impurity metal ions, while the nickel, cobalt, and magnesium metal ions in the impurity pre-extraction liquid can continue to be extracted. remain inside the first extraction raffinate.

After actual testing, it was found that after adding a certain amount of ether solvent to the first extraction agent solution, most of the impurity metal ions in the pre-extraction liquid can be removed when the extraction level is 2 (the extraction rate of impurity metal ions is greater than 99.5%), and the comparative example without adding ether solvent. When the extraction stage is 2, the extraction rate of impurity metal ions is usually around 93%. When the extraction stage is 5, the extraction rate of impurity metal ions is usually around 99%. .

This application uses extraction agent P507 to extract cobalt ions and magnesium ions in the first extraction raffinate during the second extraction step. However, after actual testing, it was found that extraction agent P507 has a good separation effect on cobalt ions and nickel ions. However, the extraction effect of the extraction agent P507 on magnesium ions is relatively average. Therefore, after using the conventional extraction agent P507 to extract cobalt ions and magnesium ions, the second extraction residue often still contains a large amount of magnesium ions, resulting in the final The quality of the finished nickel salt has a great impact. In response to this problem, the inventor surprisingly found that adding a certain amount of ketone solvent to the second extraction agent solution during the second extraction step can effectively improve the extraction effect of magnesium ions by the extraction agent P507. After adding the ketone solvent After that, the magnesium ion concentration in the final second extraction raffinate can be reduced to more than 1/10 of the original one.

In addition, in the process of extracting impurity ions in the solution using extraction agent P204 and extraction agent P507 in the first and second extraction steps, this application found that a part of the nickel ions will also be extracted by the extraction agent, thus causing nickel Loss of ions and decrease in yield. In response to this phenomenon, the applicant found that if the extraction agent P204 and the extraction agent P507 are prioritized for ion replacement, the original extraction agent P204 and the sodium soap of the extraction agent P507 are converted into nickel soap, so that the nickel of the extraction agent P204 and the extraction agent P507 After the soap encounters impurity ions such as calcium and manganese, metal ions will be replaced due to different adsorption capacities, thereby further adsorbing impurity ions such as calcium and manganese in the crude cobalt solution and reducing the second extraction The content of impurity ions in the remaining liquid does not affect the yield of nickel ions, and finally a nickel salt crystal product with extremely high purity is obtained.

As a preference, the low-acid leaching step in step (S.2) is as follows: pump the slurry into the low-acid continuous leaching tank of the leaching workshop, add 98% industrial sulfuric acid and high-acid leaching filtrate at the same time, and control the reaction temperature to 70-90 ℃ to ensure that the pH is stable at 1.0-2.0, so that metal compounds such as nickel, cobalt, manganese, copper, magnesium, aluminum, iron and other metal compounds in the powder react and dissolve with sulfuric acid to form a sulfate solution, and the reacted slurry is pumped into the pressure The filter is used for filtration, and the filtrate enters the low-acid leach solution storage tank. The filter residue is slurried and enters the high-acid leaching process.

Preferably, the high-acid leaching step in step (S.2) is as follows: after the low-acid leaching slag is slurried, it is pumped into a high-acid leaching reaction tank, sulfuric acid is added, the reaction temperature is controlled to 70-90°C, and the high-acid leaching liquid is The concentration of residual acid H ⁺ ions is 5~6mol/L. The reacted slurry is pumped into the filter press for filtration. The filtrate enters the high-acid leachate storage tank and returns to the low-acid leaching process.

Preferably, the value adjustment process in step (S.2) is as follows: pump the low-acid leach solution into the value adjustment reaction tank, add hydrogen peroxide to oxidize Fe ²⁺ in the solution to Fe ³⁺ , and heat the solution to Above 90℃, slowly add heavy calcium to adjust the pH to 4.0-5.5. Fe ³⁺ and Al ³⁺ in the solution will be hydrolyzed into the slag. Pump the reacted slurry into a filter press for filtration. After precision filtration, the filtrate will Obtain pre-extraction liquid.

Preferably, the first extraction step in step (S.3) is as follows: Dissolve the extraction agent P204 in a mixed organic solvent of ether solvent and kerosene, and prepare a first extraction agent solution of 0.5 to 1.5 mol/L. The extraction agent P204 is saponified by liquid alkali and mixed with the nickel salt solution. The extraction agent P204 is converted from sodium soap to nickel soap. The converted P204 extraction agent is countercurrently mixed with the pre-extraction liquid to remove the calcium, manganese and copper in the solution. , zinc, aluminum, iron and other metal ions are extracted into the extraction agent, and the volume ratio of the first extraction agent solution to the pre-extraction liquid is 0.5 to 2:1.

Preferably, the added amount of the ether solvent is 10 to 30 wt% of the mass of the first extractant solution.

Preferably, the ether solvent includes one or more of diglyme, ethylene glycol diethyl ether, ethylene oxide, hydroxyethyl pyrrolidone, dimethoxymethane, and cyclopentyl methyl ether. The combination.

Preferably, the second extraction step in step (S.4) is as follows: Dissolve the extraction agent P507 in a mixed organic solvent of ketone solvent and kerosene, and prepare a second extraction agent solution of 0.5 to 1.5 mol/L. The extraction agent P507 is saponified by liquid alkali and mixed with the nickel salt solution. The extraction agent P204 is converted from sodium soap to nickel soap. The converted extraction agent P507 is countercurrently mixed with the first extraction raffinate to remove the cobalt and magnesium metals in the solution. The ions are extracted into the extraction agent, and the unextracted nickel metal ions remain in the aqueous phase liquid to form a second extraction raffinate. The volume ratio of the second extraction agent solution to the pre-extraction liquid is 0.5 to 2:1.

Preferably, the ketone solvent is any one or a combination of acetylacetone, acetone, diisobutyl ketone, cyclohexanone, and methyl isobutyl ketone.

Preferably, the structure of the third extraction agent is as shown in the following formula (1):

Among them, in formula (1), R1 and R2 are independently selected from any one of H, C5-C15 branched or unbranched alkyl main chain; and at least one of R1 and R2 has a main chain structure in which Contains ketone group or nitrogen heterocycle.

In the prior art, the extraction agent used to separate cobalt and nickel is usually extraction agent P507. However, the extraction efficiency of cobalt in extraction agent P507 is low. Therefore, when using extraction agent P507 as the extraction agent for cobalt, it is found that It requires more extraction stages to achieve better extraction results for cobalt.

The applicant of the present invention found that introducing a ketone structure into the alkyl group of an alkylphosphinic acid extractant can improve the extraction effect of metal ions to a certain extent, thereby effectively reducing the number of extraction stages for cobalt. The reason is that the introduction of the ketone structure can form a good complexation reaction between the third extraction agent and the metal ions, thereby effectively improving the extraction effect of the metal ions in the second extraction raffinate.

In actual use, the inventor found that although the third extractant containing a ketone structure has a complexing effect on cobalt ions, and its complexing priority for cobalt ions is higher than that of nickel, under certain conditions it also has a complexing effect on nickel ions. Able to produce complexing effects. Moreover, the inventor found that such a third extractant containing a ketone group structure can control the complexation of cobalt and nickel by adjusting the pH value of the second extraction residue. The inventor found that when the pH value of the second extraction raffinate is greater than 3.8, its adsorption rate for cobalt is nearly 100%, while its adsorption rate for nickel drops to 0%. When the pH value of the second extraction raffinate is lower than 3.8, the extraction effect of the third extraction agent on cobalt gradually decreases, while the extraction effect on nickel gradually increases, and the pH value of the second extraction raffinate is as low as 1~ At 1.5, the extraction rate of nickel can reach almost 100%. Therefore, this property can be used to purify and extract the nickel ions in the second extraction raffinate, thereby preparing high-quality nickel salt crystal products.

Preferably, in step (S.5), the pH of the second extraction raffinate is adjusted to 1 to 1.5.

By introducing a certain amount of ether solvent into the first extraction agent solution during the extraction process, and introducing a certain amount of ketone solvent into the second extraction step, the present invention can effectively improve the concentration of waste ternary lithium-ion battery slurry. The extraction effect of impurity ions reduces the impact of these impurity ions on the quality of the final product. The extraction method in the present invention has a high extraction rate for each element in the battery, and at the same time reduces the number of extraction stages and the consumption of extraction agents, thereby effectively saving energy, saving costs, and reducing the requirements for equipment.

Description of the drawings

Figure 1 is the ¹ H-NMR spectrum of the third extractant (1) (deuterated chloroform).

Figure 2 is a ¹ H-NMR spectrum of the third extractant (2) (deuterated chloroform).

Detailed ways

The present invention will be further described below with reference to specific embodiments. A person of ordinary skill in the art will be able to implement the present invention based on these descriptions. In addition, the embodiments of the present invention mentioned in the following description are generally only some embodiments of the present invention, rather than all the embodiments. Therefore, based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts should fall within the scope of protection of the present invention.

[Preparation method of the third extraction agent]

Preparation of the third extraction agent (1):

Weigh 7.03g (80mol) of sodium phosphinate and 100mL of absolute ethanol into a 1L three-necked flask, add a magnet, and add 16mL of concentrated H ₂ SO ₄ and 0.3g of A1BN under magnetic stirring. Measure 6.72g of 3-penten-2-one and place it in a dropping funnel. Heat the oil bath to 80°C, slowly add 3-penten-2-one dropwise, and react for 6 hours. Add 0.2g of AIBN and continue the reaction for 8 hours. Then add 5.6g (80mmol) of 2-pentene. At the same time, add 0.2g of AIBN and continue the reaction for 8 hours. Cool to room temperature, filter, wash twice with 100 mL of absolute ethanol, and rotary evaporate. Dissolve with 4% NaOH until the pH of the water phase becomes strongly alkaline. _Extract with ₇₀ mL Wash the aqueous phase three times with 50mLx3 ethyl acetate. Combine the ethyl acetate phases, wash with NaCl water three times until the pH becomes neutral, dry the organic phase with anhydrous MgSO ₄ , filter, rotary evaporate, and weigh to obtain 6.19g of the third extraction agent (1), with a yield of 32%. , its ¹ H-NMR spectrum (deuterated chloroform) is shown in Figure 1.

The reaction schematic formula is as follows:

Preparation of the third extraction agent (2):

Weigh 7.03g (80mol) of sodium phosphinate and 100mL of absolute ethanol into a 1L three-necked flask, add a magnet, and add 16mL of concentrated H ₂ SO ₄ and 0.3g of A1BN under magnetic stirring. Measure 13.44g of 1-penten-3-one and place it in a dropping funnel. Heat the oil bath to 80°C, slowly add 1-penten-3-one dropwise, and react for 6 hours. Add 0.2g of AIBN and continue the reaction for 8 hours. At the same time, add 0.2g of AIBN and continue the reaction for 8 hours. Cool to room temperature, filter, wash twice with 100 mL of absolute ethanol, and rotary evaporate. Dissolve with 4% NaOH until the pH of the water phase becomes strongly alkaline. _Extract with ₇₀ mL Wash the aqueous phase three times with 50mLx3 ethyl acetate. Combine the ethyl acetate phases, wash with water and NaCl three times until the pH is neutral, dry the organic phase with anhydrous MgSO ₄ , filter, rotary evaporate, and weigh to obtain 7.68g of the third extraction agent (2), with a yield of 41%. , its ¹ H-NMR spectrum (deuterated chloroform) is shown in Figure 2.

The reaction schematic formula is as follows:

General embodiment

A method for extracting cobalt from used ternary lithium-ion batteries, including the following steps:

(S.1) Battery black powder is obtained by sequentially discharging, dismantling, crushing, sorting and pyrolyzing waste ternary lithium-ion batteries.

The details of step (S.1) are as follows:

(S.1.1) Discharge: The waste lithium battery raw materials are used in a ladder utilization workshop to sort the batteries. After testing, the batteries that meet the ladder utilization requirements are recharged and sold outside. The waste batteries that do not meet the ladder utilization requirements enter the subsequent discharge process. Commonly used The best method is to place used lithium-ion batteries in a salt solution (such as Na ₂ SO ₄ solution) for about a week.

(S.1.2) Dismantling, crushing and sorting: The discharged lithium-ion batteries enter the mechanical crushing process through the Z-shaped belt conveyor. The lithium-ion batteries are crushed through multi-stage crushing equipment with a crushing particle size of 5-10 mm. The materials are then screened into different particle sizes through vibration screening. Materials of different particle sizes undergo a combined sorting process to separate plastics and battery casings, and the remaining materials enter the next process. The dust generated during the process is collected centrally and processed.

(S.1.3) Pyrolysis: After the mechanical crushing and sorting process, the materials enter the pyrolysis furnace for pyrolysis through the fully automatic feeding system. After the pyrolysis is completed, the materials enter the next process. The flue gas generated in the pyrolysis process is cooled through catalytic combustion and accelerated cooling tower, and then enters bag dust collection + alkali washing + activated carbon filter box, and finally reaches the standard for emission.

(S.1.4) Sorting: Due to the removal of the binder, the current collector and the positive and negative electrode powders of the pyrolyzed materials are more likely to fall off. The positive and negative electrode mixed powders can be separated through vibration sorting, and the positive and negative electrode mixed powders can be separated by specific gravity. Sorting separates copper and aluminum.

(S.1.5) Crushing: The materials are sent to the first-level crusher for coarse crushing. The coarsely crushed materials are transported to the friction crusher for fine crushing. The crushed materials are screened to separate the battery black powder and copper foil or The aluminum foil is separated, and the dust generated during the breakage process is collected through a negative pressure system, and the dust is removed through a bag and the gas is discharged.

(S.2) Prepare the battery black powder material into a slurry, and then go through the low-acid leaching, high-acid leaching and value adjustment processes in sequence to obtain the impurity extraction pre-liquid;

The details of step (S.2) are as follows:

(S.2.1) Low-acid leaching process: Pump the slurry into the low-acid continuous leaching tank of the leaching workshop, add 98% industrial sulfuric acid and high-acid leaching filtrate at the same time, control the reaction temperature between 70 and 90°C, and ensure that the pH is stable at 1.0-2.0 . Metal compounds such as nickel, cobalt, manganese, copper, magnesium, aluminum, and iron in the powder react and dissolve with sulfuric acid to form a sulfate solution. The reacted slurry is pumped into the filter press for filtration, the filtrate enters the low-acid leachate storage tank, and the filter residue enters the high-acid leaching process after being slurried.

The reaction equation is as follows:

MeO+H ₂ SO ₄ →MeSO ₄ +H ₂ O (Me is metal such as Ni, Co, Mn, Fe, Al, Mg).

(S.2.2) High-acid leaching process: After the low-acid leaching slag is slurried, pump it into the high-acid leaching reaction tank, add an appropriate amount of sulfuric acid, control the reaction temperature to 70-90°C, and the residual acid H ⁺ 5-6 mol in the high-acid leaching solution /L, ensuring better nickel and cobalt leaching effects through high acid leaching. The reacted slurry is pumped into the filter press for filtration, and the filtrate enters the high-acid leachate storage tank and returns to the low-acid leaching process. The reaction equation is the same as the low acid leaching reaction.

(S.2.3) Value adjustment process:

Pump the low-acid leaching solution into the value adjustment reaction tank, add hydrogen peroxide to oxidize Fe ²⁺ in the solution to Fe ³⁺ , heat the solution to above 90°C, slowly add heavy calcium to adjust the pH to 4.0-5.5, the Fe in the solution ³⁺ and Al ³⁺ are hydrolyzed into the residue, and the reacted slurry is pumped into a filter press for filtration. After the filtrate is precision filtered, the pre-extraction liquid is obtained.

The chemical reactions of this process are as follows:

2FeSO ₄ +H ₂ O ₂ +H ₂ SO ₄ →Fe ₂ (SO ₄ ) ₃ +2H ₂ O;

Me ₂ (SO ₄ ) ₃ +6H ₂ O→2Me(OH) ₃ ↓+3H ₂ SO ₄ (Me is Al, Fe and other metals);

H ₂ SO ₄ +CaCO ₃ →CO ₂ ↑+H ₂ O+CaSO ₄ .

(S.3) Impurity extraction process: Dissolve the extraction agent P204 in a mixed organic solvent of kerosene and ether solvents to prepare a first extraction agent solution of 0.5 to 1.5 mol/L. The amount of ether solvent added is 10~30wt% of the mass of the extractant solution, saponify the P204 extractant with 32% liquid caustic soda, countercurrently mix the saponified extractant and nickel salt solution in a certain proportion, and convert the P204 extractant from sodium soap to nickel soap , the P204 extraction agent after soaping is counter-currently mixed with the pre-extraction liquid from the leaching workshop in a volume ratio of 0.5 to 2:1, and the calcium, manganese, copper, zinc, aluminum, iron and other metals in the solution are The ions are extracted into the extraction agent, and the unextracted metal ions such as nickel, cobalt, and magnesium remain in the aqueous phase material liquid. After the extraction agent is allowed to stand, they are separated from the aqueous phase material liquid to achieve the purpose of selective separation of impurity metals and obtain The first extraction raffinate containing metal ions of nickel, cobalt and magnesium.

(S.4) P507 cobalt and magnesium extraction process: Dissolve the extraction agent P507 in a mixed organic solvent of kerosene and ketone solvents to prepare a second extraction agent solution with a concentration of the extraction agent P507 of 0.5 to 1.5 mol/L. The added amount of the ketone solvent is 10 to 30 wt% of the mass of the second extraction agent solution. Saponify the P507 extractant with 32% liquid alkali. The saponified extractant and the nickel salt solution are countercurrently mixed in a certain proportion. The P507 extractant is converted from sodium soap to nickel soap. The second extractant solution after the soaping is again Countercurrently mix with the first extraction raffinate at a volume ratio of 0.5 to 2:1, perform a second extraction step, and extract cobalt ions and magnesium ions into the second extractant solution to obtain a second extraction raffinate containing nickel ions. liquid. The ketone solvent is any one or a combination of acetylacetone, acetone, diisobutyl ketone, cyclohexanone, and methyl isobutyl ketone.

(S.5) Dissolve the third extractant in kerosene to prepare a third extractant solution of 0.5 to 1.5 mol/L. Saponify the P204 extractant with 32% liquid caustic soda to adjust the concentration of the second extraction raffinate. The pH value reaches 1 to 1.5, and then the saponified third extractant solution and the second extraction raffinate are counter-currently mixed at a volume ratio of 0.5 to 2:1, and the nickel ions are extracted into the third extractant solution, carrying the extractant. Back-extract with 4N sulfuric acid solution to obtain a refined nickel sulfate solution.

(S.6) Pump the refined nickel sulfate solution into the MVR workshop and evaporate to obtain the product nickel sulfate crystals.

The above key steps (S.3)-step (S.5) were individually tested and compared. The key parameters in step (S.3) in Examples 1 to 5 and Comparative Examples 1 to 3 are as shown in Table 1 below.

Table 1

.

The metal ion content in the first extraction raffinate obtained in Examples 1 to 5 and Comparative Examples 1 to 3 is as shown in Table 2 below.

Table 2

.

It can be seen from the data in the above table that the present invention adds a certain amount of ether solvent to the first extractant solution in step (S.3), which can effectively improve the concentration of calcium, copper, zinc, aluminum, iron, and manganese metal ions. The extraction capacity effectively reduces the extraction stages.

The key parameters in step (S.4) in Comparative Examples 4 to 6 of Examples 6 to 10 are as shown in Table 3 below. The first extraction raffinate used is the first extraction raffinate obtained in Example 2.

table 3

.

The metal ion content in the second extraction raffinate obtained in Examples 6 to 10 and Comparative Examples 4 to 6 is as shown in Table 4 below.

Table 4

.

It can be seen from the data in the above table that the present invention adds a certain amount of ketone solvent to the second extractant solution in step (S.4), which can effectively improve the extraction capacity of cobalt and magnesium metal ions and effectively reduce the extraction cost. series.

The key parameters of step (S.5) are shown in Table 5 below, and the second extraction raffinate used is the second extraction raffinate obtained in Example 7.

table 5

.

The metal ion content in the refined nickel solutions obtained in Examples 11 to 14 and Comparative Examples 7 to 8 is as shown in Table 6 below.

Table 6

Note: The refined nickel solution in Examples 11 to 14 and Comparative Example 7 is the extraction agent and the solution obtained by back-extraction with 4N sulfuric acid solution is the refined nickel solution; the refined nickel solution in Comparative Example 8 is the aqueous phase liquid after extraction.

It can be seen from the data in Table 6 above that in this application, a self-made extraction agent is used and the pH of the second extraction raffinate is controlled, but the effective extraction of nickel is achieved, and the extraction pH needs to be maintained at 1 to 1.5 during use.

The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which the present invention belongs can make various modifications or additions to the described specific embodiments or substitute them in similar ways, but this will not deviate from the spirit of the present invention or exceed the definition of the appended claims. range.

Claims (10)

1. The method for extracting nickel from the waste ternary lithium ion battery is characterized by comprising the following steps of:

(S.1) sequentially discharging, disassembling, crushing, sorting and pyrolyzing the waste ternary lithium ion batteries to obtain battery black powder; (S.2) preparing black powder of the battery into slurry, and then sequentially carrying out low-acid leaching, high-acid leaching copper removal and value adjustment procedures to obtain a impurity extraction precursor solution;

(S.3) mixing the impurity extraction precursor solution with a first extractant solution containing an extractant P204 after nickel soap conversion and an ether solvent, and performing a first extraction step to remove calcium, copper, zinc, aluminum, iron and manganese metal ions in the impurity extraction precursor solution to obtain a first raffinate containing nickel, cobalt and magnesium metal ions;

(S.4) mixing the first raffinate with a second extractant solution containing the extractant P507 after nickel soap conversion and a ketone solvent, and performing a second extraction step to extract cobalt ions and magnesium ions into the second extractant solution to obtain a second raffinate containing nickel ions;

(S.5) mixing the second raffinate with a third extractant solution containing a saponified third extractant, extracting nickel ions into the third extractant solution, and carrying out back extraction on the third extractant solution to obtain a refined nickel solution;

(S.6) evaporating the refined nickel solution to obtain a nickel salt crystal product.

2. The method for extracting nickel from waste ternary lithium ion batteries according to claim 1, wherein,

the low acid leaching step in step (s.2) is as follows: pumping the slurry into a low-acid continuous leaching tank of a leaching workshop, simultaneously adding 98% industrial sulfuric acid and high-acid leaching filtrate, controlling the reaction temperature to be 70-90 ℃ to ensure that the pH value is stabilized at 1.0-2.0, enabling compounds of metals such as nickel, cobalt, manganese, copper, magnesium, aluminum, iron and the like in the powder to react with sulfuric acid to dissolve to form sulfate solution, pumping the reacted slurry into a filter press for filtering, enabling the filtrate to enter a low-acid leaching liquid storage tank, pulping the filter residue, and then entering a high-acid leaching procedure.

3. The method for extracting nickel from waste ternary lithium ion batteries according to claim 1, wherein,

the high acid leaching step in the step (s.2) is as follows: pumping the slurry into a high-acid leaching reaction tank after low-acid leaching slag and pulping, adding sulfuric acid, controlling the reaction temperature to be 70-90 ℃ and controlling residual acid H in the high-acid leaching liquid ⁺ The ion concentration is 5-6 mol/L, the reacted slurry is pumped into a filter press for filtration, and the filtrate enters a high acid leaching liquid storage tank and returns to the low acid leaching process.

4. A method for extracting nickel from waste ternary lithium ion batteries according to claim 1, 2 or 3, wherein the value adjusting procedure in the step (s.2) comprises the following steps: pumping the low-acid leaching solution into a value-adjusting reaction tank, and adding hydrogen peroxide to add Fe in the solution ²⁺ Oxidation to Fe ³⁺ Heating the solution to above 90deg.C, slowly adding heavy calcium to adjust pH to 4.0-5.5, and adding Fe into the solution ³⁺ 、Al ³⁺ Hydrolysis occurs and enters slag, the reacted slurry is pumped into a filter press for filtration, and the filtrate is subjected to precise filtration to obtain impurity extraction precursor liquid.

5. The method for extracting nickel from waste ternary lithium ion batteries according to claim 1, wherein,

the first extraction step in step (s.3) is as follows: dissolving an extractant P204 in an ether solvent and a kerosene mixed organic solvent to prepare a first extractant solution of 0.5-1.5 mol/L, saponifying the extractant P204 by liquid alkali, mixing the extractant P204 with a nickel salt solution, converting the extractant P204 from sodium soap into nickel soap, mixing the soap-converted extractant P204 with a pre-extraction liquid in a countercurrent manner, and extracting metal ions such as calcium, manganese, copper, zinc, aluminum, iron and the like in the solution into the extractant, wherein the volume ratio of the first extractant solution to the pre-extraction liquid is 0.5-2:1.

6. The method for extracting nickel from waste ternary lithium ion batteries according to claim 1 or 5, wherein the addition amount of the ether solvent is 10-30wt% of the mass of the first extractant solution.

7. A method for extracting cobalt from waste ternary lithium ion batteries according to claim 6, wherein,

the ether solvent comprises one or more of diglyme, ethylene glycol diethyl ether, ethylene oxide, hydroxyethyl pyrrolidone, dimethoxymethane and cyclopentyl methyl ether.

8. The method for extracting cobalt from waste ternary lithium ion batteries according to claim 1, wherein,

the second extraction step in step (s.4) is as follows: dissolving extractant P507 in a mixed organic solvent of ketone solvent and kerosene to prepare a second extractant solution of 0.5-1.5 mol/L, saponifying the extractant P507 by liquid alkali, mixing the extractant P507 with a nickel salt solution, converting extractant P204 from sodium soap to nickel soap, countercurrent mixing the soap-converted extractant P507 with the first raffinate, extracting cobalt and magnesium metal ions in the solution into the extractant, and leaving nickel metal ions which are not extracted in the aqueous phase feed liquid to form a second raffinate, wherein the volume ratio of the second extractant solution to the raffinate is 0.5-2:1.

9. The method for extracting cobalt from waste ternary lithium ion batteries according to claim 1 or 8, wherein the ketone solvent is any one or a combination of more of acetylacetone, acetone, diisobutylketone, cyclohexanone and methyl isobutyl ketone.

10. The method for extracting cobalt from waste ternary lithium ion batteries according to claim 1, wherein,

in the step (S.5), the pH value of the second raffinate is adjusted to 1-1.5;

the structure of the third extractant is shown in the following formula (1):

wherein R1 and R2 in the formula (1) are respectively and independently selected from any one of branched or unbranched alkyl main chains of H, C5-C15; and at least one of R1 and R2 contains a ketone group or an azacyclic ring in its main chain structure.