KR20150094412A - Method for recovering valuable metals from cathodic active material of used lithium battery - Google Patents

Abstract

The present invention relates to a valuable metal recovering method. The method includes the steps of: separating lithium compounds from the positive electrode materials of a waste lithium ion battery through hydrogenation or carbon reduction; and leaching the positive electrode materials of the waste lithium ion battery separated from the lithium compounds in a strong acid to separate the metal compounds including Ni, Co, and Mn. More specifically, the valuable metal recovering method omits a process of purifying a reactant added to recover the valuable materials to be economical and recover the metal compounds including Ni, Co, and Mn and lithium compounds from the positive electrode materials of the waste lithium ion battery respectively at a high purity rate and recovery rate.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method for recovering valuable metals from a cathode material of a waste lithium ion battery,

The present invention relates to a method for recovering valuable metals from a cathode material of a waste lithium ion battery, and more particularly to a method for recovering lithium, nickel, cobalt and manganese from a cathode material of a waste lithium ion battery at a high purity and recovery rate ≪ / RTI >

The present invention was derived from the research conducted as a part of the technical innovation development project of the Small and Medium Business Administration [Task Control Number: S2045890, Title: Development of NMC precursor and high purity lithium compound manufacturing technology using lithium ion battery scrap as raw material].

Since lithium ion batteries have high energy density and light weight characteristics, they are being used as power sources for small portable equipment. Recently, the usage of lithium ion batteries has been rapidly increasing. In recent years, it is widely used not only for small household appliances and mobile products but also as a power source for hybrid electric vehicles (HEV / EV).

Such a lithium ion battery is composed of an anode and a cathode, an organic electrolyte and an organic separator. Specifically, a lithium ion battery includes a plastic casing and an anode, a cathode, Organic separators, organic electrolytes, and Ni-coated steel casings.

On the other hand, the positive electrode of a lithium ion battery is composed of a positive electrode material, a conductor, a binder and a current collector. The active material is excellent in reversibility, low self discharge rate, high capacity, high energy density, Lithium cobalt oxide (LiCoO ₂ ), which is easy to synthesize, is widely used. In recent years, ternary lithium composite metal oxides such as Li (Ni _x Co _y Mn _z ) O ₂ including Ni, Mn and the like are also used as a positive electrode material in order to reduce the amount of expensive cobalt (Co) . However, all of the above-mentioned cathode materials contain at least 5% by weight of lithium and a large amount of valuable metals such as nickel, cobalt and manganese, so that they are interested in a method for recovering expensive valuable metals from the cathode material of a spent lithium ion battery Attention is being paid. Li (Ni _x Co _y Mn _z ) O ₂ (NCM) has been applied as a high-capacity anode material for a hybrid electric vehicle (HEV). Therefore, there is a need for reprocessing and recycling of bad scrap in NCM-based anode materials for battery automobiles, which are expected to be produced in earnest.

Conventionally, one of the methods for recovering valuable metals from waste lithium ion batteries is a method of dissolving a positive electrode material of a waste lithium ion battery using a strong acid such as nitric acid, sulfuric acid, hydrochloric acid, and then performing a neutralization reaction to separate and recover lithium and other metal compounds Was used. However, in the above-mentioned recovery method, since lithium and a metal compound are eluted into an acid and separated, there is a need to further process to separate a lithium compound from other metal compounds in order to use it again in the production of a lithium ion battery.

Another known method for recycling secondary battery cathode materials is to recover cobalt, nickel, and manganese, which are valuable metals, and recover lithium in the form of lithium carbonate using sodium carbonate. In this case, sodium acts as an impurity There is a disadvantage that the washing process must be repeated several times.

Accordingly, there is a need to develop a method for recovering lithium, nickel, cobalt and manganese from a cathode material of a spent lithium ion battery in an easier manner.

The present invention provides a recovery method of organometallic compounds capable of recovering lithium, nickel, cobalt and manganese from a cathode material of a waste lithium ion battery at high purity and recovery rate.

The present invention relates to a method for separating a lithium compound by hydrogen reduction or carbon reduction of a cathode material of a waste lithium ion battery, Forming a strong acid leaching aqueous solution containing nickel, cobalt, and manganese by leaching a positive electrode material of the waste lithium ion battery into which the lithium compound is separated, in a strong acid; Separating the manganese compound by adding an oxidizing agent to the strong acid leaching aqueous solution; And extracting residual amounts of manganese compounds, nickel and cobalt from the aqueous leach solution of strong acids from which the manganese compounds have been separated by using a solvent extraction method, respectively.

Hereinafter, a method for recovering a valuable metal from a cathode material of a waste lithium ion battery according to a specific embodiment of the present invention will be described in detail.

As used herein, the term "carbon-based compound" refers to a compound containing carbon and includes all organic compounds including carbon, inorganic compounds including carbon, and the like.

As used herein, the term " valuable metal "includes lithium, nickel, cobalt, and manganese.

In the present specification, the term " positive electrode material of a lithium ion battery "means a material other than a conductor, a binder and a current collector among constituent components of a positive electrode of a lithium ion battery.

According to an embodiment of the present invention, there is provided a method of separating a lithium compound by hydrogen reduction or carbon reduction of a cathode material of a waste lithium ion battery; Forming a strong acid leaching aqueous solution containing nickel, cobalt, and manganese by leaching a positive electrode material of the waste lithium ion battery into which the lithium compound is separated, in a strong acid; Separating the manganese compound by adding an oxidizing agent to the strong acid leaching aqueous solution; And extracting residual amounts of manganese compounds, nickel and cobalt from the aqueous leaching solution of strong acid in which the manganese compound has been separated by using a solvent extraction method, respectively.

The inventors of the present invention have found out that the cathode material of the waste lithium ion battery is reduced by a specific method so that the lithium compound is separated and recovered and the remaining valuable metal compound is leached into the strong acid and then oxidizing agent and solvent extracting agent are sequentially used, It has been confirmed through experiments that the valuable metal contained in the ion battery can be easily recovered at a high recovery rate, and the invention is completed.

The recovering method of the valuable metal separates the lithium compound from the spent lithium ion battery by using the hydrogen reduction or the carbon reduction method, so that the additional process used for purifying the sodium can be omitted without using sodium carbonate, And other metal compounds can be separated and recovered in high purity, so that the step of separating them can be omitted, which is economical and simple.

Further, in the above-described method for recovering valuable metals, the positive electrode material of the waste lithium ion battery in which the lithium compound is separated is leached into strong acid to form a strong acid leaching aqueous solution containing nickel, cobalt and manganese, The manganese compound is separated by adding an oxidizing agent and the residual manganese compound, nickel and cobalt can be respectively extracted from the strong acid leaching aqueous solution in which the manganese compound is separated by using the solvent extraction method. Through this process, the lithium compound and the manganese compound, nickel and cobalt can be easily separated and recovered with high yield and purity, respectively.

Particularly, when an oxidizing agent is first added to an aqueous solution of a strong acid leaching solution containing nickel, cobalt and manganese to separate a manganese compound from a predetermined level or more, and then the remaining manganese compound, nickel and cobalt are separated and extracted using a solvent extraction method , A high purity manganese compound, nickel and cobalt can be separated with higher efficiency.

As shown in Examples and Comparative Examples to be described later, when a solvent extraction method is applied to a strong acid leaching aqueous solution containing nickel, cobalt, and manganese simply by separating a valuable metal, the separation efficiency is greatly reduced, Purity may not be high.

Most of the manganese compounds contained in the strong acid leaching aqueous solution can be separated through the step of adding an oxidizing agent to the strong acid leaching aqueous solution to separate the manganese compounds. Specifically, the weight ratio of manganese to nickel in the strong acid leaching solution from which the manganese compound is separated may be 20% or less, or 10% or less. As described above, if the weight ratio of manganese to nickel in the strong acid leaching solution from which the manganese compound has been separated by separating the manganese compound by adding an oxidizing agent to the strong acid leaching aqueous solution is 20% or less, or 10 weight% or less, The residual amount of manganese compound, nickel and cobalt can be extracted with higher efficiency by the solvent extraction method.

Specific examples of the oxidizing agent include ozone, manganese (IV) oxide, sodium sulphate (K2S2O8), sodium hypochlorite (NaClO), potassium permanganate, chlorine dioxide, Or mixtures thereof.

The oxidizing agent may be added in an amount of 1 to 4 equivalents based on manganese contained in the strong acid leaching aqueous solution.

The remaining manganese compounds, nickel and cobalt can be respectively extracted from the strong acid leaching aqueous solution in which the manganese compound is separated through a commonly known solvent extraction method.

Specifically, the solvent extraction method may include mixing an organic solvent containing the strong acid leaching aqueous solution and the extracting agent from which the manganese compound is separated.

The extractant may be a compound known to be capable of extracting a valuable metal such as phosphate, phosphinic acid, phosphonate, aliphatic having 8 to 20 carbon atoms A carboxylic acid, an amine compound, a hydroxyoxime, a phosphoric ester, a phosphonic ester, a phosphine oxide, a phosphine sulphide, or a mixture of two or more thereof .

Examples of the extraction agent include trioctylamine, decylamine, octadecanamide, di (2-ethylhexyl) phosphate, 2-ethylhexyl-mono (2-ethylhexyl) phosphonate, bis (2,4,4-trimethylpentyl) phosphonic acid [Bis (2,4,4-trimethylpentyl) di (2-ethylhexyl) phosphonic acid], tri-acylphosphine oxide, dimethylheptyl methyl phosphate, E- 2-ethylhexyl methyl phosphonic acid di (2-ethylhexyl) ester, 2-ethylhexylmethylphosphonic acid di (2-ethylhexylmethylphosphonic acid) ) ester, dibutyl butyl phosphonate, tributylphosphine, or a mixture of two or more thereof can be used. .

The extractant may be used in a diluted state using a diluent known to be used in a solvent extraction method.

The volume ratio (O / A) of the organic phase to the water-soluble phase may be 0.5 to 3.0 in the step of mixing the aqueous solution containing the strong acid extracted with the manganese compound and the organic solvent containing the extractant.

Meanwhile, in the method for recovering a valuable metal in the embodiment, after the lithium compound is separated from the positive electrode material of the waste lithium ion battery by the hydrogen reduction or the carbon reduction described above, the resultant product in which the lithium compound is separated is leached into strong acid, Without using hydrogen peroxide, metal compounds including nickel, cobalt and manganese can be separated.

The strong acid may include sulfuric acid, nitric acid, or a mixture thereof. However, when sulfuric acid is used, a valuable metal such as nickel, cobalt, and manganese can be recovered at a relatively low concentration and a high leaching rate.

The strong acid may be 0.1 to 5 M concentration, preferably 2 to 4 M concentration. When the reaction is carried out with a strong acid having a concentration in the above range, nickel, cobalt and manganese are eluted at a high rate, and the recovery of metal compounds including nickel, cobalt and manganese may be high. However, when the concentration of the strong acid is less than 0.1M, the amount of the metal compound eluted into the strong acid may be too small. When the concentration of the strong acid exceeds 5M, the increase of the leaching amount depending on the concentration of the strong acid is insignificant It may not be ensured.

Nickel, cobalt, and manganese may be contained in the metal compound including nickel, cobalt, and manganese leached into the strong acid solution in the form of metal ions, metal oxides, metal particles, and more preferably in a metal ion state .

And, in the step of leaching the positive electrode material into a strong acid, the solid-liquid ratio of the positive electrode material of the spent lithium ion battery recovered from the lithium compound to strong acid may be 50 to 150 g / L. When the solid ratio is less than 50 g / L, the amount of leaching is small depending on the amount of strong acid, so that economical efficiency may not be sufficiently secured. If the solid ratio exceeds 150 g / L, the valuable metal is not well leached into strong acid, And the leaching rate of the metal compound of the positive electrode material into the strong acid may be low.

The manganese compound can be separated by adding an oxidizing agent to the strong acid leaching aqueous solution after leaching the positive electrode material of the waste lithium ion battery from which the lithium compound is separated into strong acid to form a strong acid leaching aqueous solution containing nickel, cobalt and manganese .

The method for recovering the valuable metal may further include adjusting pH of the strong acid leaching solution to 1.0 to 7.0, or 1.5 to 6.5.

The pH of the strong acid leaching solution can be determined in consideration of the composition of the strong acid leaching solution, the oxidizing agent used, and the extractant used in the solvent extraction method to be applied hereinafter. The method of controlling the pH is not limited to a wide range, and conventionally known methods such as acid addition and alkali addition can be used.

Meanwhile, the cathode material of the waste lithium ion battery may include at least one valuable metal selected from the group consisting of nickel, cobalt, manganese, and lithium. Specifically, the cathode material separated from the waste lithium ion battery may contain 1 to 50% by weight of nickel, 1 to 50% by weight of cobalt, 1 to 50% by weight of manganese and 1 to 10% by weight of lithium, By weight to 5% by weight.

The cathode material of the waste lithium ion battery may contain not only the metal itself but also organic or inorganic compounds of metal in various forms. Specifically, the cathode material of the waste lithium ion battery is selected from the group consisting of lithium cobalt oxide (LiCoO ₂ ), lithium cobalt nickel manganese oxide (LiCoNiMnO ₂ ), lithium cobalt nickel oxide (LiCo 1-yN y O ₂ , 0 <y < (LiMnO _2), lithium-manganese-phosphorus oxide (LiMnPO _4), lithium iron phosphate (LiFePO ₄₎ and lithium-nickel-aluminum oxide _{(LiNi 1 - z Al z O} 2, 0.05 = z = 0.5) at least one selected from lithium composite metal Oxide. &Lt; / RTI &gt;

The cathode material of the spent lithium ion battery may have an average particle size in various ranges, but may preferably have a particle size (D50) of 1 to 20 mu m. When the particle size of the spent lithium ion battery is too large or small, the aforementioned hydrogen reduction or carbon reduction may not occur uniformly, and it may not be easy to efficiently separate the above-described valuable metal.

As described above, the high-purity lithium compound can be efficiently separated according to the hydrogen reduction or carbon reduction of the cathode material of the spent lithium ion battery.

The lithium compound separated by hydrogen reduction or carbon reduction may be lithium oxide, lithium hydroxide, lithium carbonate, or a mixture of two or more thereof, more preferably a lithium carbonate crystal.

The hydrogen reduction in the step of separating the lithium compound may be performed by reacting the positive electrode material of the waste lithium ion battery with the hydrogen gas. Specifically, the hydrogen reduction in the step of separating the lithium compound may include a step of charging hydrogen gas into the cathode material of the spent lithium ion battery and heating the cathode material of the spent lithium ion battery to 400 ° C to 800 ° C .

As the hydrogen reduction reaction progresses, lithium contained in the cathode material of the waste lithium ion battery can be converted into a form of a separable compound, and the cathode material can be converted into a form in which a valuable metal other than lithium is reduced have.

The hydrogen gas may be introduced at a rate of 0.1 to 10 L / min, preferably at a rate of 0.5 to 2 L / min. When the charging rate of the hydrogen gas is out of the above range, the reduction reaction may not be efficiently performed.

After the hydrogen gas is introduced into the cathode material of the waste lithium ion battery, the cathode material and the hydrogen gas of the waste lithium ion battery can be heated to 400 ° C to 800 ° C to reduce the cathode material. In particular, the valuable metal contained in the positive electrode material may exist in the form of a lithium composite metal oxide of Li (M) O ₂ (where M is Co, Ni, Mn), which reacts with hydrogen gas at 400 ° C. to 800 ° C. , It can be reduced to LiO ₂ , Co, Ni, MnO form. That is, a lithium compound such as lithium oxide can be formed from the cathode material of the waste lithium ion battery by the hydrogen reduction reaction, and can be separated through a water washing process or a reaction process with carbon dioxide, which will be described later.

The heating temperature and the heating time during the reaction of the cathode material and the hydrogen gas of the waste lithium ion battery are not particularly limited, but may be specifically performed at a temperature of 400 ° C to 800 ° C for 5 minutes to 24 hours. The heating temperature can be adjusted within a range of 400 to 800 占 폚, but preferably at a temperature of 600 to 800 占 폚. When heating is carried out in the above-mentioned preferable temperature range, the lithium recovery rate may be high. When the heating temperature is lower than 400 ° C., the reduction reaction of the composite metal oxide in the cathode material of the waste lithium ion battery does not occur due to the low temperature, so that the recovery rate of the lithium compound may be low. A side reaction such as re-coupling of the reduced lithium compound and the composite metal oxide occurs, and the recovery rate of the lithium compound may be lowered.

The heating time can be preferably adjusted in consideration of the amount of the positive electrode material of the waste lithium ion battery and the temperature condition, in the range of 5 minutes to 24 hours. If the heating time is less than 5 minutes, the reduction reaction of the cathode material may occur insufficiently. If the heating time exceeds 24 hours, the effect of increasing the recovery rate of the lithium compound with increase of the heating time is insignificant.

The cathode material and the hydrogen gas of the spent lithium ion battery can be heated at a rate of 1 DEG C / minute to 20 DEG C / minute. The rate of temperature increase can be controlled preferably in consideration of the amount of the positive electrode material of the spent lithium ion battery and the final heating temperature, and the positive electrode material can be reduced with higher reaction efficiency by heating at the heating rate within the above range.

Meanwhile, the recovering method of the valuable metal may further include a step of reacting the result of hydrogen reduction of the cathode material of the spent lithium ion battery with carbon dioxide gas. The result of hydrogen reduction may include lithium metal and lithium oxide, which can be converted into lithium carbonate by separation with carbon dioxide.

In particular, from about the moment when about two minutes have elapsed since the reaction of the hydrogen reduction product and the carbon dioxide started, a white solid lithium carbonate crystal from the lithium metal and the lithium oxide included in the hydrogen reduction product can be formed.

The carbon dioxide gas may be an inert gas such as nitrogen or air mixed in addition to carbon dioxide, and the carbon dioxide gas is not limited to a gas containing only carbon dioxide.

Meanwhile, the carbon reduction in the step of separating the lithium compound may be performed by reacting the positive electrode material of the waste lithium ion battery with the carbon-based compound. Specifically, the carbon reduction in the step of separating the lithium compound may include a step of charging the carbonaceous compound into the cathode material of the spent lithium ion battery and heating the battery to 400 ° C to 800 ° C.

As the carbon reduction reaction proceeds, the lithium contained in the cathode material of the waste lithium ion battery can be converted into a form of a separable compound, for example, lithium carbonate, etc. In the cathode material, Can also be converted to a reduced form.

The carbon-based compound to be added to the reduction reaction of the above-mentioned positive electrode generally refers to a compound containing carbon as defined above, and its constitution is not limited. However, in order to increase the efficiency of the reduction reaction, High carbon compounds can be used.

Specifically, as the carbon-based compound, carbon powder or activated carbon having a particle size (D50) of 1 to 10 mu m may be preferably used. The carbon powder having a particle size within the above range has a large surface area, and the reaction between the cathode material and the carbon powder of the waste lithium ion battery can be more easily performed. In particular, lithium in the cathode material can be separated into lithium compounds at a high recovery rate have.

The carbon-based compound may be added in an amount of 0.5 to 2 moles, preferably 1 to 1.5 moles, per mole of the cathode material of the waste lithium ion battery. When the carbon-based compound is added excessively, unreacted carbon may remain as an impurity, and it is preferable to mix the carbon-based compound in the molar ratio within the above range.

The carbonaceous compound may be added to the cathode material of the spent lithium ion battery and heated to 400 to 800 ° C to reduce the valuable metal contained in the cathode material. In particular, the valuable metal compound contained in the positive electrode material may be present in the form of lithium composite metal oxide of Li (M) O ₂ (where M is Co, Ni, Mn) And can be reduced to the form of Li ₂ CO ₃ , Co, Ni, MnO. That is, a lithium compound such as lithium carbonate can be formed from the cathode material of the waste lithium ion battery by the carbon reduction reaction, and can be separated through a water washing process or a concentration process, which will be described later.

The heating temperature and the heating time in the reaction of the cathode material and the carbon compound of the waste lithium ion battery are not particularly limited but may be performed at a temperature of 400 ° C to 800 ° C for 5 minutes to 24 hours. The heating temperature can be adjusted within a range of 400 to 800 占 폚, but preferably at a temperature of 600 to 800 占 폚. In the case of heating to the above preferable temperature range, the lithium recovery rate may be high.

On the other hand, when the heating temperature is lower than 400 ° C., the reduction reaction of the composite metal oxide in the cathode material of the waste lithium ion battery does not occur due to the low temperature, so that the recovery rate of the lithium compound may be low. , There is little increase in the recovery rate due to the rise in temperature, and the economical efficiency of the process may not be sufficiently secured.

The heating time can be suitably adjusted in consideration of the amount of the positive electrode material of the waste lithium ion battery and the temperature condition in the range of 5 minutes to 24 hours. If the heating time is less than 5 minutes, the reduction reaction of the cathode material may occur insufficiently. If the heating time exceeds 24 hours, the effect of increasing the recovery rate of the lithium compound with increase of the heating time is insignificant.

Meanwhile, the step of separating the lithium compound includes a step of crushing the product of hydrogen reduction or the product of carbon reduction; Or water washing step.

More specifically, the step of separating the lithium compound is a step of separating the lithium compound from the result of the hydrogen reduction produced from the heating step of the hydrogen reduction or the carbon reduction reaction or the result of the hydrogen reduction Or the step of crushing the result of the carbon reduction.

When a hydrogen gas or a carbon compound is added to the cathode material of the spent lithium ion battery and heated, massive particles including a lithium compound, a lithium composite metal oxide, and a composite metal contained in the lithium composite metal oxide may be produced, A process of crushing the lumpy particles to increase the surface area can be additionally performed in order to separate the lithium compound more efficiently.

A mill, a hammer mill, a screw mill, a roll mill, a disc mill, or a jog mill, which are generally used for grinding, May be used. However, the present invention is not limited to the above-described example. Preferably, the weight average particle diameter is 30 to 500 占 퐉. When the weight average particle diameter after pulverization is less than 30 占 퐉, the pulverized particles may not be handled easily, the process efficiency due to excessive pulverization is inferior, When the weight average particle diameter after the pulverization exceeds 500 탆, the effect of increasing the surface area of the particles is insignificant, so that the efficiency of the elution process due to pulverization may be insignificant.

The step of separating the lithium compound may further include the step of further washing the resultant product of hydrogen reduction or the product of carbon reduction with water to selectively separate the lithium compound at a high recovery rate.

The washing step may be performed without being limited to the process order. For example, it may be performed selectively after the heating step or the pulverizing step, but the lump-shaped positive electrode material produced by hydrogen reduction or carbon reduction It is preferable to crush to increase the surface area, to wash water more easily, and to separate the lithium compound separately at a high recovery rate.

At this time, the water washing step may be performed by rinsing in water at 10 to 90 ° C for 10 minutes to 24 hours, and lithium hydroxide in the step of rinsing lithium as a result of mass reduction of hydrogen or carbon reduction, It can be separated into water in the form of a lithium compound such as lithium carbonate. The aqueous solution containing the lithium compound can be separated from the resultant hydrogen reduction product or the resultant product of carbon reduction from the solid lump material which is not dissolved in water to separate the aqueous solution containing the lithium compound separately. The lithium compound crystals can be separated through a concentration process or the like.

The washing time is not limited, but may be 10 minutes to 24 hours, more preferably 1 hour to 12 hours, in consideration of solubility of the lithium compound and the like. If the water is washed for a short time, the amount of the lithium compound to be eluted may be small, and if it is washed more than 24 hours, the increase in the elution amount of the lithium compound due to the increase in washing time is insignificant.

In order to increase the purity of the lithium compound to be separated and minimize the components flowing out in the washing step, the amount of the hydrogen reduction or carbon reduction is controlled to 10 g / L to 500 g / L. &lt; / RTI &gt;

Further, a crystal form of the lithium compound can be obtained by further concentrating the aqueous solution containing the lithium compound obtained through the washing step. The lithium compound may be lithium hydroxide or lithium carbonate. The method of concentration can be selected and used as long as it can be used as a concentration method for obtaining a crystal form in an aqueous solution such as concentration under reduced pressure, freezing concentration, evaporation concentration, heating concentration, precipitation concentration, reverse osmosis concentration and the like.

According to the present invention, it is possible to omit the step of purifying the reactant added for recovering the valuable metal, and it is economical and economical to use the lithium compound and the nickel compound including nickel, cobalt and manganese at high purity and recovery rate from the cathode material of the spent lithium- A method of recovering a valuable metal from a cathode material of a waste lithium ion battery capable of recovering a metal compound can be provided.

1 is a schematic view of a reducing apparatus used in the embodiment.
2 is an XRD graph of a hydrogen-reduced sample of Example 1. Fig.
3 is an XRD graph of a sample of Example 1 washed with hydrogen and then washed.
4 is a graph showing the leaching rate of lithium to the washing liquid of Example 1 washed with hydrogen and then washed.
FIG. 5 is a graph showing leaching rates of each sample for sulfuric acid for each metal. FIG.
6 is a graph showing the carbon reduction reaction rate and the weight loss rate of each of the samples according to Example 1;
7 is an XRD graph of a carbon reduced sample of Example 2. Fig.
8 is an XRD graph of a sample of Example 2 washed with water after carbon reduction.
9 is a graph showing the leaching rate of lithium into the wash liquor of Example 2 washed with water after carbon reduction.
10 is an XRD graph of the lithium carbonate powder obtained in Example 2. Fig.
11 is a SEM photograph of the lithium carbonate powder obtained in Example 2. Fig.
12 is a graph showing the leaching rate of sulfuric acid in each sample of the sample washed with water after carbon reduction in Example 2. FIG.
FIG. 13 is a graph showing the leaching rates of the samples not subjected to the carbon reduction treatment and the samples washed at 700 ° C. after the carbon reduction in Example 2 by the respective sulfuric acid concentrations.
14 is a graph showing experimental results according to the concentration change of the extracting agent in Example 4. Fig.
15 is a graph showing extraction results according to the volume ratio of the organic phase to the aqueous phase in Example 4. FIG.
16 is a graph showing the metal extraction ratio results according to the number of times of extraction performed in Example 4. FIG.

The invention will be described in more detail in the following examples. However, the following examples are illustrative of the present invention, and the present invention is not limited by the following examples.

[ Example  1: recovery of valuable metal through hydrogen reduction]

One. Preparation of anode material samples of waste lithium ion batteries

A sample of the positive electrode material containing the metal component of the following Table 1 was prepared.

Ni Co Mn Li Al Content (% by weight) 31.7 10.6 15.7 6.6 0.08

* The anode material sample contains remaining oxygen and the like other than the above-mentioned metal components

2. Recovery step of lithium compound

(1) Device

The reducing unit is composed of a heating unit, a temperature adjusting unit and a gas adjusting unit. The heating unit uses a SiC heating element. The chamber has a size of 200 mm * 200 mm * 400 mm (width * length * A thermocouple and a PID temperature controller were used. The gas control unit was designed to flow three types of gas, and a flow meter for 5 L / min was installed to allow hydrogen gas and nitrogen gas to flow quantitatively. A schematic view of the used reducing apparatus is shown in Fig.

(2) Hydrogen reduction step

Nitrogen gas was flowed at a rate of 1 L / min while raising the temperature inside the chamber to the reaction temperature at a rate of 5 캜 / min. When the reaction temperature was reached, 100 g of the positive electrode material sample prepared in the above step 1 was introduced into a reduction apparatus, and the reaction temperature was maintained for 1 hour while flowing hydrogen gas having a purity of 99% or more.

After the holding time, nitrogen gas was flowed until the temperature of the chamber dropped to about 200 ° C in order to block the hydrogen gas and prevent the oxidation of the chamber. In order to prevent damage of the rubber ring for sealing the chamber, Was poured into the chamber.

The other conditions were the same, and the reaction temperature was varied five times under the five temperature conditions of 400 ° C., 500 ° C., 600 ° C., 700 ° C. and 800 ° C., and the weight of the sample before and after the hydrogen reduction step Reduction ratio and the state of the sample are shown in Table 2 below.

Condition Weight of sample (g) Weight Reduction Rate (%) Reduction rate (%) The state of the sample after reduction Before reduction After reduction 400 ° C, 1h 100.21 98.81 1.4 8.4 powder 500 ° C, 1h 100.13 92.64 7.5 45.1 Lump 600 ° C, 1h 100.00 86.22 13.8 71.0 Lump 700 ° C, 1h 100.07 87.07 13.0 78.3 Lump 800 ° C, 1h 100.10 84.62 15.5 93.3 Lump

(3) Washing step

100 g of the powder of the sample subjected to the hydrogen reduction treatment was put into 1 L of water and was rinsed with water for 1 hour. Then, CO ₂ gas was flowed at a rate of 1 L / min for 30 minutes to 500 ml of the washing solution of the sample to obtain 18 g of white lithium carbonate particles.

The XRD graphs of the hydrogen-reduced sample and the sample washed after hydrogen reduction are shown in FIGS. 2 and 3, and the lithium content of the wash liquid of the sample is analyzed, and the leaching rate of lithium is shown in FIG.

* Leaching rate of lithium = lithium content of wash water solution / lithium content of initial sample

3. Separation of metal compounds including nickel, cobalt and manganese

A sample not subjected to hydrogen reduction treatment and a sample washed with water after hydrogen reduction at 500 ° C were introduced into sulfuric acid at a concentration of 1M, 2M, 3M and 4M at a liquid ratio of 100 g / L and leached in sulfuric acid.

The leaching rate of the sample with respect to sulfuric acid is shown in FIG. 5 for each metal.

4. Analyze Results

(1) According to the above Table 2, the weight reduction of the sample according to the reduction reaction using the hydrogen of Example 1 was from 400 ° C, and a large decrease of more than 13% was observed especially above 600 ° C. The reduction of the weight of the sample is caused by the water vapor generated by the reduction reaction, which is reflected in the reduction ratio, and shows a high reduction ratio of 70% or more at 600 ° C or more.

(2) The crystal change of the hydrogen reduced sample and the sample washed after hydrogen reduction in Example 1 can be evaluated by the XRD graphs of FIGS. 2 and 3. More specifically, in the 400 ℃ but Li (NCM) O ₂ peak is slightly present, the 500 ℃ not present and the Li (NCM) O ₂ peak, was a Co / Ni, MnO, Li ₂ O peak exists, 600 ℃ A peak of LiMnO ₂ began to be generated. Therefore, from the graph, it can be deduced that Co, Ni, MnO, and Li ₂ O are produced at a temperature of 500 ° C or higher because the sample is not reduced at 400 ° C and mostly exists in an initial state. However, at 600 ℃ or higher, it is assumed that the manganese oxide decomposed at high temperature reacted with lithium again to generate LiMnO ₂ .

(3) The leaching rate obtained by analyzing the lithium content of the leached solution after the hydrogen reduction reaction was found to be 75% or more at 500 ° C. or higher as shown in FIG. 4. The purity of recovered lithium carbonate was about 99% Respectively.

(4) As shown in FIG. 5, which is a graph showing the leaching rate of sulfuric acid before and after the reduction treatment of the sample and the leaching rate of sulfuric acid by concentration, the leaching efficiency of cobalt and nickel at 2M sulfuric acid concentration Respectively, by 32% and 45%, respectively, and by manganese by 90%. The leaching rate of the sample subjected to the hydrogen reduction treatment into the 3M sulfuric acid solution showed 89% of cobalt, 99% or more of nickel and 99% or more of manganese, and the cobalt, nickel and manganese It was confirmed that lean metal could be leached into sulfuric acid.

[ Example  2: recovery of valuable metal through carbon reduction]

1. Preparation of anode material samples

A sample of the positive electrode material containing the metal components of the following Table 3 was prepared.

Ni Co Mn Li Al Content (% by weight) 9.6 8.2 34.7 5.4 1.3

* The anode material sample contains remaining oxygen and the like other than the above-mentioned metal components

2. Recovery step of lithium compound

(1) Carbon reduction step

500 ° C. and 600 ° C. in the same manner as in Example 1, except that 100 g of the mixture prepared by mixing the positive electrode material sample prepared in 1 and the carbon powder at a molar ratio of 1: , 700 ° C, and 800 ° C. The carbon reduction reaction rate and the weight loss rate at each temperature are shown in Tables 4 and 6.

Condition Weight Reduction Rate (%) 400 ° C, 1h 3 500 ° C, 1h 7 600 ° C, 1h 8 700 ° C, 1h 13 800 ° C, 1h 15

(2) Washing step

The sample subjected to the carbon reduction treatment was put in water at a powder liquid ratio of 40 and was washed with water for 3 hours. The XRD graphs of the carbon reduced sample and the sample washed after the carbon reduction are shown in FIGS. 7 and 8, and the lithium content of the wash liquid of the sample is analyzed, and the leaching rate of lithium is shown in FIG.

(3) Evaporation Concentration Step

Then, lithium carbonate was recovered by concentrating the wash water of the sample subjected to the carbon reduction treatment at a temperature of 70 ° C and a pressure of 100 mbar using an evaporator, and the purity of the lithium carbonate powder was about 99% or more. The XRD and SEM results of the lithium carbonate powder are shown in FIGS. 10 and 11. FIG.

3. Separation of metal compounds including nickel, cobalt and manganese

(1) The sample washed with water after the carbon reduction was leached at a liquid ratio of 100 g / L to 2 M sulfuric acid, and the leaching rate of the sample with respect to sulfuric acid at each temperature is shown in FIG.

(2) A sample not subjected to the carbon reduction treatment and a sample washed with water after the carbon reduction at 700 ° C were introduced into sulfuric acid at a concentration of 1M, 2M, 3M and 4M at a liquid ratio of 100 g / L and leached in sulfuric acid. The leaching rate of the sample with respect to sulfuric acid is shown in FIG. 13 for each metal.

4. Analyze Results

(1) According to the above Table 4 and FIG. 6, the weight reduction of the sample according to the reduction reaction using the carbon of Example 2 was from 400 ° C, and a large decrease of more than 13% was observed above 700 ° C. The reduction of the weight of the sample was caused by the carbon monoxide gas generated by the reduction reaction, which was also reflected in the reduction rate, and showed a high reduction ratio of 70% or more at 700 ° C or more.

(2) The crystal change of the sample reduced in carbon and the sample washed after hydrogen reduction in Example 2 can be evaluated by the XRD graphs of FIGS. 7 and 8. More specifically, there existed a Li (NCM) O ₂ peak at 400 ° C., but the Li (NCM) O ₂ peak began to change from 500 ° C., and there existed Co, Ni, MnO and Li ₂ CO ₃ peaks at 600 ° C. . Therefore, from the graph, it can be deduced that Co, Ni, MnO, and Li ₂ CO ₃ are produced from the sample at a temperature of 500 ° C. or higher, although the sample is not reduced at 400 ° C. and is mostly present in an initial state. However, unlike in Example 1, the peak of LiMnO ₂ was not generated at 600 ° C or higher in the carbon reduction of Example 2, and it is estimated that the manganese oxide is not carbon reduced at a high temperature.

As shown in FIG. 9, the leaching rate obtained by analyzing the lithium content of the leached solution after the hydrogen reduction reaction was 60% or more at a temperature of 600 ° C. or higher, and the leaching rate of lithium from 600 ° C. The reason for this is presumably because lithium reacts with carbon at 600 ° C to produce Li ₂ CO ₃ . The purity of recovered lithium carbonate was found to be about 99%. From FIGS. 10 and 11, which are XRD and SEM photographs of the lithium carbonate particles, it can be seen that the lithium carbonate is formed in the shape of an irregular shape.

(4) As shown in Figs. 12 and 13, which are graphs showing the results of leaching of sulfuric acid before and after the reduction treatment of the sample and the leaching rates of sulfuric acid according to the concentration of sulfuric acid, cobalt and nickel The leaching efficiency was improved by 40% and 45%, respectively. In the case of manganese, there was almost no leaching in the sulfuric acid before the reduction treatment, but it was improved more than 99% according to the reduction to manganese oxide after the reduction treatment. In addition, the leaching rate of the sample subjected to the carbon reduction treatment to a sulfuric acid solution of 2M or more shows 99% or more of all of cobalt, nickel and manganese, and the cobalt, nickel, It was confirmed that leaching can be carried out with sulfuric acid.

[ Comparative Example 1 : Recovery of valuable metal in sulfuric acid leaching solution]

The NCM-based anode scrap generated in the lithium ion battery manufacturing process was reduced using a carbon compound (the method of Example 2), and a solution was prepared by removing lithium and leaching into sulfuric acid. The composition of the sulfuric acid leaching solution was analyzed by ICP (Inductively Coupled Plasma, GBC Integra XL) after leaching into the water. The results are shown in Table 5 below.

Composition of sulfuric acid leaching solution Ni Co Mn Li Concentration (g / L) 45.97 27.94 18.01 0

Then, the pH of the sulfuric acid leaching solution was adjusted to 5.5, and the organic phase containing the extractant was mixed. After reacting for a predetermined period of time, the solution was allowed to stand for about 60 minutes, and phase separation was performed to filter the aqueous phase. And the distribution coefficient, separation factor and extraction ratio for each metal were determined and are shown in Table 6 below.

Escaid 100 was used to remove the aroma of the kerosene component. D2EHPA (di-2-ethylhexyl phosphoric acid) was used as the extractant for the removal of manganese and PC88A (2- ethylhexyl phosphonic acid mono-2-ethylhexyl ester) and Cyanex272 (di-2,4,4-trimethylpentyl phosphinic).

Results of solvent extraction Extractant
(Concentration:% by volume) O / A ratio Controlled pH Metal component Distribution coefficient
D Separation factor
beta Extraction rate
E (%) PC88A-10% One 7.0 Co 1.11 D _Co / D _Ni = 1.20 52.6 Ni 0.93 48.1 Mn 2.39 D _Mn / D _Ni = 2.58 70.5 PC88A-15% One 5.2 Co 1.36 D _Co / D _Ni = 1.49 57.6 Ni 0.91 47.7 Mn 3.94 D _Mn / D _Ni = 4.31 79.8 PC88A-20% One 4.2 Co 1.41 D _Co / D _Ni = 1.62 58.4 Ni 0.87 46.4 Mn 3.94 D _Mn / D _Ni = 4.54 79.7 Cyanex 272-10% 2 5.5 Co 1.60 D _Co / D _Ni = 1.82 76.2 Ni 0.88 63.8 Mn 3.54 D _Mn / D _Ni = 4.02 87.6 Cyanex272-15% 2 4.4 Co 1.32 D _Co / D _Ni = 1.92 72.6 Ni 0.69 57.9 Mn 3.01 D _Mn / D _Ni = 4.37 85.8 Cyanex 272-20% 2 4.1 Co 1.27 D _Co / D _Ni = 2.00 71.7 Ni 0.63 55.9 Mn 3.06 D _Mn / D _Ni = 4.82 86.0

As shown in Table 6 above, when the ratio of manganese to nickel (Mn / Ni) is about 39%, the separation coefficients of the PC88A and Cyanex27215-17, which are effective solvents for separating cobalt and nickel, 10, it was found that cobalt and nickel were not separated smoothly. Cyanex272 rather than PC88A was found to have a higher extraction rate of cobalt and manganese as a whole.

In the case of nickel, it should be separated by water, but the organic phase is about 40%, which is because the content of manganese is too high to prevent the separation of cobalt and nickel. As a result, it was found that it is inefficient to separate the NCM solution containing manganese in the solvent.

[ Example 3 : Removal of manganese from sulfuric acid leaching solution using an oxidizing agent and solvent extraction]

(1) Removal of manganese from the sulfuric acid leaching solution

The NCM-based anode scrap generated in the lithium ion battery manufacturing process was reduced using a carbon compound (the method of Example 2), and a solution was prepared by removing lithium and leaching into sulfuric acid. The composition of this sulfuric acid leaching solution was the same as in Comparative Example 1 above.

The pH of the sulfuric acid leach solution was adjusted to the values shown in Table 7 below. Then, potassium permanganate was added to the distilled water to make a solution. The amount of manganese contained in the sulfuric acid leaching solution was calculated, and the potassium permanganate aqueous solution was added (ratio shown in Table 7 below). After 1 hour, Quantitative analysis was performed. The results of the removal efficiency of manganese by potassium permanganate and the effect on cobalt and nickel are shown in Table 7.

Reaction conditions
1) pH of solution
2) Equivalent ratio of manganese / potassium permanganate Cobalt leaching rate
(Co leaching rate) Nickel leaching rate
(Ni leaching rate) Manganese leaching rate
(Mn leaching rate) Mn / Ni
(%) pH = 2
Mn / KMnO ₄ = 1.5 63.5% 72.6% 3.5% 2.0 pH = 3
Mn / KMnO ₄ = 1.5 58.9% 64.2% 3.0% 1.9 pH = 4
Mn / KMnO ₄ = 1.5 55.6% 61.2% 2.1% 1.4 pH = 2,
Mn / KMnO ₄ = 4.5 61.6% 58.5% 20.6% 13.4 pH = 2,
Mn / KMnO ₄ = 4.0 63.2% 60.2% 22.5% 14.2 pH = 2,
Mn / KMnO ₄ = 3.5 70.0% 70.8% 17.2% 9.2 pH = 2,
Mn / KMnO ₄ = 3.0 63.8% 65.5% 8.8% 5.1 pH = 2,
Mn / KMnO ₄ = 2.0 50.4% 61.5% 2.5% 2.6 pH = 4,
Mn / KMnO ₄ = 2.5 62.4% 73.8% 15.2% 8.4 pH = 4,
Mn / KMnO ₄ = 2.0 61.9% 75.1% 2.9% 1.6

As shown in Table 7, when the potassium permanganate was added at a predetermined equivalent ratio to the amount of manganese and tested at various pHs, the manganese removal efficiency was about 75% or more or 95% or more. When manganese was precipitated, cobalt and nickel Was also found to be present in the NCM solution in the presence of 56 to 64% of cobalt and 61 to 73% of nickel.

When the amount of nickel relative to manganese is calculated, the ratio (Mn / Ni) before removing manganese is lowered from about 39% to 1.4%. In order to separate cobalt and nickel according to Mn / Ni, a solution of manganese removed was subjected to solvent extraction test using Mn / Ni = 5.1% (concentration of manganese in NCM solution is about 1500 ppm).

(2) Separation of nickel, cobalt and residual manganese from the manganese-free sulfuric acid leaching solution

The pH of the solution in which the manganese was removed (Mn / Ni = 5.1%, the concentration of manganese in the NCM solution was about 1500 ppm) was adjusted to 5.5, and the organic phase containing the extractant was mixed and reacted for a predetermined time. And the phase separation was performed. The aqueous phase was filtered to measure the concentration of metal ions, and the partition coefficient, separation factor and extraction ratio for each metal were determined and are shown in Table 6 below.

Escaid 100 was used as a diluent. Escherichia coli (Escaid 100) was used as a diluent. As an extractant for solvent extraction, PC88A (2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester), Cyanex272 2,4,4, -trimethylpentyl phosphinic) was used.

The solvent extraction results are shown in Table 8 below.

Solvent / concentration used (vol%) O / A ratio Controlled pH Metal component Distribution coefficient
D Separation factor
beta Extraction rate
E (%) PC88A-10% One 7.4 Co 44.2 D _Co / D _Ni = 43 97.8 Ni 1.0 51.0 Mn 253.5 D _Mn / D _Ni = 244 99.6 PC88A-15% One 5.9 Co 47.5 D _Co / D _Ni = 50 97.9 Ni 1.0 48.7 Mn 304.4 D _Mn / D _Ni = 321 99.7 PC88A-20% One 5.5 Co 26.4 D _Co / D _Ni = 36 96.4 Ni 0.7 42.6 Mn 151.7 D _Mn / D _Ni = 204 99.3 Cyanex 272-10% 2 6.3 Co 371.0 D _Co / D _Ni = 1529 99.9 Ni 0.2 32.7 Mn 1526.0 D _Mn / D _Ni = 6290 100 Cyanex272-15% 2 5.6 Co 256.5 D _Co / D _Ni = 13996 99.8 Ni 0.02 3.5 Mn 609.8 D _Mn / D _Ni = 33269 99.9 Cyanex 272-20% 2 5.2 Co 130.8 D _Co / D _Ni = 3648 99.6 Ni 0.04 6.7 Mn 586.3 D _Mn / D _Ni = 16352 99.9

As shown in Table 8, in the case of PC88A, the extraction ratio of manganese was more than 99% and the cobalt was extracted more than 95%. Nickel, however, was extracted by about 43% at 20% PC88A concentration. In the case of Cyanex272, the extraction rate of manganese and cobalt was over 99%, and nickel was extracted at less than about 4% at the concentration of 15% Cyanex272, indicating that nickel, manganese and cobalt were efficiently separated. When the separation factor of cobalt and manganese for nickel was calculated, it was confirmed to be about 10,000 or more, so that it is possible to separate cobalt and nickel in one stage even though it is usually separated.

[ Example 4 : Removal of manganese from sulfuric acid leaching solution using an oxidizing agent and solvent extraction]

(1) Removal of manganese from the sulfuric acid leaching solution

The NCM-based anode scrap generated in the lithium ion battery manufacturing process was reduced using a carbon compound (the method of Example 2), and a solution was prepared by removing lithium and leaching into sulfuric acid. The composition of this sulfuric acid leaching solution was the same as in Comparative Example 1 above.

The pH of the sulfuric acid leaching solution was adjusted to the values shown in Table 9 below. Then, the amount of manganese contained in the sulfuric acid leach solution was calculated, and the chlorine dioxide (8% aqueous solution) was added thereto, reacted for about 1 hour, and then filtered to quantitatively analyze the filtrate. Table 9 shows the results of the removal efficiency of manganese by chlorine dioxide and the effect on cobalt and nickel.

Reaction conditions
1) pH of solution
2) Equivalent ratio of manganese / chlorine dioxide Cobalt leaching rate
(Co leaching rate) Nickel leaching rate
(Ni leaching rate) Manganese leaching rate
(Mn leaching rate) Mn / Ni
(%) pH = 2.0
ClO ₂ / Mn = ₂ 99% 99% 60.8% 17.9 pH = 4.0
ClO ₂ / Mn = ₂ 94% 99% 41.8% 16.0 pH = 6.2
ClO ₂ / Mn = ₂ 95% 98% 39.5% 15.8 pH = 2.0
ClO ₂ / Mn = 3 96% 99% 22% 9.8 pH = 2.0
ClO ₂ / Mn = 4 95% 99% 12% 4.7 pH = 6.2
ClO ₂ / Mn = 3 98% 99% 23% 7.9

As shown in Table 9, manganese removal efficiencies were 39.2% at pH = 2 and 58.2% at pH = 4, respectively, when cobalt and nickel were leached by at least 95% and 60.5% at pH = 6, respectively.

In addition, the leaching rates of cobalt and nickel were not significantly changed even when the amount of chlorine dioxide was changed in order to increase the removal efficiency of manganese. However, the removal efficiency of manganese was 1.5 The ratio of Mn / Ni decreased to 72.9% in the case of pear and 87.1% in case of 2.0 times, and decreased to 17.9, 9.8 and 4.7 as the equivalence ratio increased to 2, 3 and 4, respectively.

In the condition of pH = 6 and equivalent ratio of 1.5 times, it increased to 77.4% and Mn / Ni was 7.9, which was 50% higher than that of the equivalent ratio of 1: 1. As a result, the removal efficiency of manganese increased as the pH was increased and the equivalence ratio increased, and Mn / Ni, which can easily separate nickel from cobalt by solvent extraction, was below 5%.

(2) Manganese-free sulfuric acid leaching In the solution,  Separation of cobalt and residual manganese

The pH of manganese-free solution (Mn / Ni = 5%, concentration of manganese in NCM solution: about 1700 ppm) was adjusted to 2.0, and the organic phase containing the extractant was mixed and reacted for a predetermined time. The solution was filtered through phase separation, and the concentration of metal ions was measured.

Escherichia coli (Escaid 100) was used as a diluent. Di-2-ethylhexyl phosphoric acid (D2EHPA) was used for the removal of manganese as an extractant used for solvent extraction. , And the volume ratio (O / A) of the organic phase to the aqueous phase was about 1.

The concentration of the extractant was varied from 10 vol.% To 40 vol.% At 10% intervals. The results are shown in FIG. 14. As shown in FIG. 14, manganese increased from about 19% to about 50% at a D2EHPA concentration of 40 vol.% As the concentration of the extractant increased. In the case of cobalt and nickel, the concentration of the extractant decreased to 30 vol.%, But slightly increased to 40 vol.%. The extraction rate of cobalt and nickel at 30 vol.% Was about 6% and 8% . In the subsequent experiments, the concentration of the extraction ratio was fixed at 30 vol.%.

  Next, the experiment was carried out while changing the ratio (O / A ratio) of the organic phase to the aqueous phase during extraction. The results are shown in FIG. As shown in FIG. 15, the extraction ratio of manganese increased with increasing of the proportion, and showed about 72% at O / A = 2. In the case of cobalt and nickel, the extraction ratio tended to increase with the increase of the proportion, and it was about 10% in the case of O / A = 1 or more.

The extraction of manganese was carried out in several stages because it was not extracted at about 50% by one solvent extraction. FIG. 16 shows the metal extraction rate according to the number of times of extraction. In the case of manganese extraction, the extraction rate was about 99%, and in the case of cobalt and nickel, about 17% and 11% . .

On the other hand, a solvent extraction experiment was performed to separate cobalt and nickel from the solution from which manganese was removed by solvent extraction using the extractant D2EHPA. The solvent extraction conditions were 15% Cyanex 272, O / A = 2, and initial pH = 5.5. At equilibrium pH = 5.0, the extraction rate of cobalt was more than 99%, and nickel was extracted less than about 7%, indicating that nickel and cobalt were efficiently separated.

Claims (18)

Separating the lithium compound by hydrogen reduction or carbon reduction of the cathode material of the spent lithium ion battery;
Forming a strong acid leachate solution containing nickel, cobalt and manganese by leaching a positive electrode material of the waste lithium ion battery into which the lithium compound has been separated in a strong acid;
Separating the manganese compound by adding an oxidizing agent to the strong acid leachate solution; And
And extracting remaining manganese compounds, nickel and cobalt from the strong acid leachate solution in which the manganese compound is separated by using a solvent extraction method.
The method according to claim 1,
Wherein the weight ratio of manganese to nickel in the strong acid leaching solution from which the manganese compound is separated is 20% or less.
The method according to claim 1,
Wherein the oxidant is selected from the group consisting of at least one compound selected from the group consisting of ozone, manganese oxide (IV), sodium sulphate (K ₂ S ₂ O ₈ ), sodium hypochlorite (NaClO), potassium permanganate, Recovery method.
The method according to claim 1,
Wherein the oxidizing agent is added in an amount of 1 to 4 equivalents based on manganese contained in the strong acid leaching aqueous solution.
The method according to claim 1,
Wherein the solvent extraction method comprises mixing an aqueous solution of a strong acid leached with the manganese compound separated and an organic solvent containing an extracting agent.
6. The method of claim 5,
Wherein the extractant is selected from the group consisting of phosphate, phosphinic acid, phosphonate, an aliphatic carboxylic acid having 8 to 20 carbon atoms, an amine compound, a hydroxyoxime, a phosphoric ester, A method for recovering valuable metals, comprising at least one compound selected from the group consisting of phosphonic esters, phosphine oxides, and phosphine sulphides.
6. The method of claim 5,
The extractant may be selected from the group consisting of trioctylamine, decylamine, octadecanamide, di (2-ethylhexyl) phosphate, 2-ethylhexyl- Bis (2,4,4-trimethylpentyl) phosphinic acid (2-ethylhexyl) -mono (2-ethylhexyl) ester and bis (2,4,4-trimethylpentyl) phosphonic acid di- (2-ethylhexyl) phosphonic acid, tri-acylphosphine oxide, dimethylheptyl methyl phosphate, E-hexyl- Ethylhexyl methyl phosphonic acid di (2-ethylhexyl) ester [E-hexyl-4-ethyloctyl isopropylphosphonic acid], 2-ethylhexylmethylphosphonic acid di- ], Dibutyl butyl phosphonate, and tributylphosphine. [0033] The term &quot; It is a method for recovering valuable metals.
6. The method of claim 5,
Wherein the volume ratio (O / A) of the organic phase to the aqueous phase is 0.5 to 3.0 in the step of mixing the aqueous solution containing the strong acid extracted with the manganese compound and the organic solvent containing the extracting agent.
The method according to claim 1,
Further comprising adjusting the pH of the strong acid leaching solution to 1.0 to 7.0.
The method according to claim 1,
Wherein the cathode material of the spent lithium ion battery has a particle size (D50) of 1 to 20 占 퐉.
The method according to claim 1,
Wherein the positive electrode material of the spent lithium ion battery comprises at least one valuable metal selected from the group consisting of nickel, cobalt, manganese, and lithium.
The method according to claim 1,
Wherein the hydrogen reduction is performed by charging hydrogen gas into the cathode material of the spent lithium ion battery and heating the battery at 400 to 800 ° C.
13. The method of claim 12,
The hydrogen gas is supplied at a flow rate of 0.1 to 10 L / min,
Wherein the cathode material and the hydrogen gas of the waste lithium ion battery are heated at a temperature raising rate of 1 占 폚 / min to 20 占 폚 / min.
13. The method of claim 12,
Further comprising the step of reacting the result of hydrogen reduction with carbon dioxide.
The method according to claim 1,
Wherein the carbon reduction includes a step of adding a carbonaceous compound to the cathode material of the spent lithium ion battery and heating to 400 to 800 占 폚.
16. The method of claim 15,
Wherein the carbon-based compound comprises a carbon powder having a particle size (D50) of 1 to 10 mu m.
16. The method of claim 15,
Wherein the carbon-based compound is added in an amount of 0.5 to 2 moles per mole of the cathode material of the waste lithium ion battery.
The method according to claim 1,
Wherein the strong acid has a concentration of 0.1M to 5M.

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