JP6984055B2 - Method for concentrating valuable metals contained in lithium-ion secondary batteries - Google Patents

Description

The present invention relates to a method for concentrating valuable metals contained in a lithium ion secondary battery.

Lithium-ion secondary batteries are lighter, higher capacity, and higher electromotive power secondary batteries than conventional lead storage batteries and Nikkado secondary batteries, and are used as secondary batteries for personal computers, electric vehicles, portable devices, etc. Has been done. For example, the positive electrode of the lithium ion secondary battery, valuable metals such as cobalt or nickel, lithium cobaltate (LiCoO _2), ternary positive electrode active material _{(LiNi x Co y Mn z O} 2 (x + y + z = 1)) It is used as such.

Since the use of lithium-ion secondary batteries is expected to continue to expand in the future, lithium-ion secondary batteries that are discarded due to defective products generated during the manufacturing process, equipment used, and battery life, such as cobalt and nickel, etc. It is desired to concentrate the valuable metals of the above from the viewpoint of resource recycling.

For example, as a technique for recovering valuable metal from the waste material of a lithium ion secondary battery, the waste material of the secondary battery is heated at 300 to 500 ° C. in an oxygen-containing gas stream to separate and remove the metal foil, and the recovered material is again oxygenated. A method of recovering as a metal compound for a positive electrode material by heating at 500 to 650 ° C. in a contained gas stream to remove combustible substances has been proposed (see Patent Document 1). In this method, the thermal decomposition treatment is performed in two stages, the decomposition of graphite in the electrode material is suppressed as much as possible until the electrode material is peeled off from the metal foil in the first stage, and the metal foil is separated and removed first. In the second stage, graphite is decomposed to suppress the sintering phenomenon in which the particle size of the recovered metal compound becomes large as much as possible.

Further, for example, aluminum is effective by heating a lithium ion battery wrapped in an aluminum housing at a low temperature condition of 400 to 550 ° C. and heating a crushed and separated battery powder under a sieve at a high temperature condition of 550 to 700 ° C. Further, a method of changing a valuable metal such as cobalt into a form suitable for magnetic separation or buoyancy has been proposed (see Patent Document 2).

However, since the technique described in Patent Document 1 aims to reuse the recovered electrode material as it is as a metal compound for positive electrode materials, it pays no attention to recovering nickel or cobalt as a metal. No.
Further, the technique described in Patent Document 2 is intended for a battery using a cobalt-based positive electrode material such as lithium cobalt oxide, and separates cobalt from a mixture of aluminum, lithium aluminate, copper, copper oxide, carbon and the like. aims to cobalt, such as ternary positive electrode material _{(LiNi x Co y Mn z O} 2 (x + y + z = 1)), an oxide containing nickel, manganese, separated by a heat treatment and physical sorting of manganese No mention was made of that.

As a technique for concentrating cobalt and nickel from a lithium ion secondary battery, for example, a technique has been proposed in which an electrode material is fired in the presence of oxygen and the fired body is leached into an inorganic acid to separate and concentrate cobalt, copper and aluminum. (See, for example, Patent Document 3). In this prior art, cobalt and aluminum can be leached into an inorganic acid to separate copper. In addition, cobalt and aluminum can be separated by adjusting the pH of the inorganic acid.

Further, for example, a two-stage solvent extraction step is performed on a metal mixed aqueous solution containing a metal group A composed of lithium, manganese, nickel, and cobalt and a metal group B composed of copper, aluminum, and iron, and the metal group B is formed. And a technique for separating manganese from lithium, nickel and cobalt has been proposed (see, for example, Patent Document 4).

Further, for example, a technique has been proposed in which a waste lithium ion secondary battery is thermally decomposed by superheated steam at 350 ° C. to 550 ° C., crushed and classified to concentrate valuable metals contained in a positive electrode material (for example, Patent Document). 5). As a result, organic substances contained in the lithium ion secondary battery can be thermally decomposed at low cost while suppressing metal oxidation and generation of dioxin, and aluminum contained in the housing and the positive electrode current collector (melting point 660). Valuable metals contained in the positive electrode material can be concentrated without melting (° C).

However, the technique described in Patent Document 3 as described above has a problem that complicated steps such as filtration of an inorganic acid and pH adjustment are required.
Further, in the technique described in Patent Document 4, for example, since solvent extraction is used to separate manganese from cobalt, nickel and lithium, there is a problem that the extractant cost and the equipment introduction cost become excessive.
Further, in the technique described in Patent Document 5, for example, although aluminum and copper can be separated at a high concentration rate, cobalt and nickel are not metallized, and metals such as lithium, cobalt, nickel and manganese are mixed compounds. It was only concentrated as.

Japanese Unexamined Patent Publication No. 2000-348782 Japanese Unexamined Patent Publication No. 2017-37807 Japanese Unexamined Patent Publication No. 2019-169309 Japanese Patent No. 5706457 International Publication No. 2012/169073 Pamphlet

INDUSTRIAL APPLICABILITY According to the present invention, a metal content enriched with cobalt and nickel can be easily obtained for a used lithium ion secondary battery, a positive electrode material for a used lithium ion secondary battery, or scraps in the manufacturing process thereof. Concentration of valuable metals contained in lithium-ion secondary batteries, which facilitates separation of cobalt and nickel, as well as manganese, from composite oxides containing cobalt, nickel and manganese as positive electrode active materials, especially other battery components. The purpose is to provide a method.

As a result of diligent studies by the present inventors in order to solve the above-mentioned problems, cobalt and nickel as positive electrode active materials contained in a lithium ion secondary battery are in the form of an oxide containing cobalt, nickel, manganese and lithium. However, by performing heat treatment under specific conditions based on thermodynamic theoretical calculation, cobalt and nickel of oxides are changed to metals, and manganese and the like are allowed to exist as oxides. It was found that the metal content with increased (concentrated) concentrations of cobalt and nickel can be efficiently obtained.

The present invention is based on the above-mentioned findings by the present inventors, and the means for solving the above-mentioned problems are as follows. That is,
<1> Included in a lithium-ion secondary battery that treats a lithium-ion secondary battery containing at least one element of cobalt and nickel or a positive electrode material thereof to concentrate a valuable metal containing at least one of cobalt and nickel. It is a method of concentrating valuable metals.
A heat treatment step of heat-treating the lithium ion secondary battery or its positive electrode material to form a granule containing at least one valuable metal of cobalt and nickel.
A method for concentrating valuable metals contained in a lithium ion secondary battery, which comprises.
<2> Concentration of the valuable metal contained in the lithium ion secondary battery according to <1>, wherein the lithium ion secondary battery or its positive electrode material is heat-treated in a reducing atmosphere or an inert atmosphere in the heat treatment step. Method.
<3> The lithium ion secondary battery according to <1> or <2>, wherein the lithium ion secondary battery is heat-treated in a state of being housed in a case having a melting point equal to or higher than the heat treatment temperature in the heat treatment step. How to concentrate valuable metals.
<4> The method for concentrating valuable metals contained in a lithium ion secondary battery according to <3>, wherein the case is an outer case in the pack, module, or cell of the lithium ion secondary battery.
<5> In the heat treatment step, the heat treatment is performed in a state where 10% by mass or more of carbon is present with respect to the total mass% of at least one of cobalt and nickel contained in the lithium ion secondary battery or its positive electrode material. The method for concentrating valuable metals contained in a lithium ion secondary battery according to any one of <1> to <4>.
<6> The method for concentrating valuable metals contained in a lithium ion secondary battery according to <5>, wherein the carbon contains carbon derived from a negative electrode material of the lithium ion secondary battery.
<7> A crushing step of crushing the heat-treated product of the lithium ion secondary battery or its positive electrode material obtained by the heat treatment step.
A sorting step of selecting and recovering a product in which at least one of cobalt and nickel is concentrated from the crushed product of the heat-treated product obtained by the crushing step.
The method for concentrating valuable metals contained in a lithium ion secondary battery according to any one of <1> to <6>, further comprising.
<8> The sorting process is
The first sorting step of classifying the crushed product obtained in the crushing step using a sieve having a sieve mesh of 0.1 mm to 2.4 mm into coarse-grained products and fine-grained products.
The second sorting step of separating the fine-grained products obtained in the first sorting step by utilizing at least one difference in magnetism, particle size, and specific gravity.
The method for concentrating valuable metals contained in the lithium ion secondary battery according to <7>.
<9> The fine pulverization step of further pulverizing the fine granule product obtained in the first sorting step is included.
The method for concentrating valuable metals contained in a lithium ion secondary battery according to <8>, wherein the second sorting step is performed on the finely pulverized product obtained in the finely pulverized step.
<10> The method for concentrating valuable metals contained in a lithium ion secondary battery according to <9>, wherein the cumulative 50% volume particle diameter D _{50 of the finely pulverized product is 75 μm or less.}
<11> Lithium according to any one of <7> to <10>, wherein the sorting step is a magnetic force sorting step, and the magnetic flux density of the magnet in the magnetic force sorting step is 0.01 tesla or more and 2 tesla or less. A method for concentrating valuable metals contained in an ion secondary battery.
<12> The method for concentrating valuable metals contained in a lithium ion secondary battery according to <11>, wherein the magnetic force sorting step is wet magnetic force sorting.
<13> The method for concentrating valuable metals contained in a lithium ion secondary battery according to <12>, wherein 50 mg / L or more of a dispersant is added to the slurry applied in the wet magnetic force sorting.
<14> The method for concentrating valuable metals contained in a lithium ion secondary battery according to <12> or <13>, wherein the slurry applied in the wet magnetic force sorting is subjected to particle dispersion treatment by ultrasonic waves.
<15> Concentration of valuable metals contained in the lithium ion secondary battery according to any one of <1> to <14>, wherein the heat treatment is performed at 750 ° C. or higher and 1200 ° C. or lower for 1 hour or longer in the heat treatment step. Method.
<16> Included in a lithium-ion secondary battery that treats a lithium-ion secondary battery containing at least one element of cobalt and nickel or a positive electrode material thereof to concentrate a valuable metal containing at least one of cobalt and nickel. It is a method of concentrating valuable metals.
A heat treatment step of heating the lithium ion secondary battery or its positive electrode material to 600 ° C to 1200 ° C.
A crushing and classifying step of crushing and classifying the heat-treated product obtained in the heat treatment step,
A reheat treatment step of heating the fine granule product obtained in the crushing classification step to 300 ° C. to 1200 ° C. again to form a granule containing at least one valuable metal of cobalt and nickel, and a reheat treatment step.
A method for concentrating valuable metals contained in a lithium ion secondary battery, which comprises.
<17> The method for concentrating valuable metals contained in a lithium ion secondary battery according to <16>, wherein the negative electrode material in the lithium ion secondary battery contains carbon.
<18><16> or <17>, which comprises a sorting step of sorting and recovering a product in which at least one of cobalt and nickel is concentrated from the reheat-treated product obtained in the reheat treatment step. The method for concentrating valuable metals contained in the lithium ion secondary battery according to the above.
<19> The lithium ion secondary battery according to <18>, which recovers a product enriched with at least one of cobalt and nickel and a product concentrated with manganese in the sorting step. Method for concentrating valuable metals.
<20> The valuable value contained in the lithium ion secondary battery according to <18> or <19>, wherein the sorting step is a step of performing separation using at least one difference in magnetism, particle size, and specific gravity. Metal concentration method.
<21> The item according to any one of <16> to <20>, wherein in the heat treatment step, the lithium ion secondary battery is housed in a case containing aluminum and the aluminum derived from the case is separated at the time of heating. A method for concentrating valuable metals contained in lithium-ion secondary batteries.
<22> In the crushing classification step, crushing by impact, shearing or compression is performed, and classification is performed using a sieve having a sieve mesh of 0.1 mm to 2.4 mm, any one of <16> to <21>. The method for concentrating valuable metals contained in the lithium ion secondary battery according to the above.
<23> In the reheat treatment step, any one of <16> to <22>, wherein the cumulative 50% volume particle diameter D _{50 in the granules containing at least one metal of cobalt and nickel is 1 μm or more.} The method for concentrating valuable metals contained in the lithium ion secondary battery according to the two sections.
<24> The lithium according to any one of <18> to <23>, wherein the sorting step is a magnetic force sorting step, and the magnetic flux density of the magnet in the magnetic force sorting step is 0.01 tesla or more and 2 tesla or less. A method for concentrating valuable metals contained in an ion secondary battery.
<25> The method for concentrating valuable metals contained in a lithium ion secondary battery according to <24>, wherein the magnetic force sorting step is wet magnetic force sorting, and a dispersant of 50 mg / L or more is added to the slurry to be applied.
<26> The method for concentrating valuable metals contained in a lithium ion secondary battery according to <25>, wherein the slurry applied in the wet magnetic force sorting is subjected to particle dispersion treatment by ultrasonic waves.
<27> The lithium ion secondary according to any one of <16> to <26>, wherein a reducing component is added to form a reducing atmosphere in at least one of the heat treatment step and the reheat treatment step. A method for concentrating valuable metals contained in batteries.
<28> In the heat treatment step or the reheat treatment step, a part of the heat treatment time is heated in an air atmosphere or an oxidizing atmosphere to reduce the quality of the reduced component of the heat-treated product or the re-heat-treated product. The method for concentrating valuable metals contained in a lithium ion secondary battery according to any one of <16> to <27>.
<29> The lithium ion secondary battery according to any one of <18> to <28>, wherein the re-crushing step of re-crushing the heat-treated product is performed after the re-heat treatment step and before the sorting step. A method for concentrating valuable metals contained in.
<30> The claim that a magnetic force sorting step using a magnetic force is performed on the fine-grained product obtained in the crushing classification step, and the reheat treatment step is performed on the magnetically deposited material obtained in the magnetic force sorting step. The method for concentrating valuable metals contained in a lithium ion secondary battery according to any one of <16> to <29>.

According to the first embodiment of the present invention, the lithium ion secondary battery or the positive electrode material thereof is heat-treated to form granules containing at least one valuable metal of cobalt and nickel, so that cobalt and nickel are concentrated. It is possible to provide a method for concentrating valuable metals contained in a lithium ion secondary battery, in which a metal component can be easily obtained and easily separated from other battery components.
Further, according to the second embodiment of the present invention, since the crushing classification is performed after the heat treatment at a predetermined temperature and the heat treatment is performed again, the metal content in which cobalt and nickel are concentrated can be easily obtained, and other batteries can be obtained. It is possible to provide a method for concentrating valuable metals contained in a lithium ion secondary battery, which can be easily separated from the constituent components.
In other words, according to the present invention, it is easy to obtain a metal content enriched with cobalt and nickel for a used lithium ion secondary battery, a positive electrode material of a used lithium ion secondary battery, or process scraps thereof. The valuables contained in the lithium-ion secondary battery, which facilitates the separation of cobalt, nickel, and even manganese from composite oxides containing cobalt, nickel, and manganese as positive electrode active materials. A method for concentrating a metal can be provided.

FIG. 1 shows a fine-grained product (including a positive electrode material) obtained by heat-treating, crushing, and sieving a ternary lithium-ion secondary battery containing cobalt, nickel, and manganese in an embodiment of the present invention. It is a scanning electron microscope (SEM, manufactured by Hitachi High-Technologies Corporation, TM4000Plus) photograph showing a part of the above. All SEM photographs of the drawings of the present application were taken using the same apparatus. FIG. 2 shows a fine-grained product (including a positive electrode material) obtained by heat-treating, crushing, and sieving a ternary lithium-ion secondary battery containing cobalt, nickel, and manganese in an embodiment of the present invention. It is an SEM photograph which shows some other example of a part of. FIG. 3A shows a fine-grained product (including a positive electrode material) obtained by heat-treating, crushing, and sieving a ternary lithium-ion secondary battery containing cobalt, nickel, and manganese in an embodiment of the present invention. It is an SEM photograph which shows a part example of the thing which was reheat-treated at 1000 degreeC in the state which contained carbon. FIG. 3B shows a fine-grained product (including a positive electrode material) obtained by heat-treating, crushing, and sieving a ternary lithium-ion secondary battery containing cobalt, nickel, and manganese in an embodiment of the present invention. It is a figure which shows the element peak by EDS (energy dispersive X-ray spectroscope, AZtecone manufactured by Oxford) of the grain mass in an example of the thing which reheated at 1000 degreeC in the state which contained carbon. The elemental peaks by EDS in the drawings of the present invention were all obtained by using the same apparatus. FIG. 3C shows a fine-grained product (including a positive electrode material) obtained by heat-treating, crushing, and sieving a ternary lithium-ion secondary battery containing cobalt, nickel, and manganese in an embodiment of the present invention. It is a figure which shows the element peak by EDS (energy dispersion type X-ray spectroscope) of the manganese oxide in an example of the thing which reheated at 1000 degreeC in the state which contains carbon. FIG. 3D is an SEM photograph showing the state of grain mass formation after 1 hour of reheat treatment for 2 hours in the embodiment of the present invention. FIG. 4A is an SEM photograph of an example of a fine-grained product before wet magnetic force sorting in an embodiment of the present invention. FIG. 4B is a diagram showing element peaks by EDS (energy dispersive X-ray spectroscope) in an example of fine-grained products before wet magnetic force sorting in the embodiment of the present invention. FIG. 4C is a diagram showing element peaks by EDS (energy dispersive X-ray spectroscope) in an example of fine-grained products before wet magnetic force sorting in the embodiment of the present invention. FIG. 5A is an SEM photograph of an example of a fine-grained product after wet magnetic force sorting in an example of the present invention. FIG. 5B is a diagram showing element peaks by EDS (energy dispersive X-ray spectroscope) in an example of fine-grained products after wet magnetic force sorting in the embodiment of the present invention. FIG. 5C is a diagram showing element peaks by EDS (energy dispersive X-ray spectroscope) in an example of fine-grained products after wet magnetic force sorting in the embodiment of the present invention. FIG. 6A is an SEM photograph taken of an example of finely pulverized particles which are lumps of metal and oxide in the embodiment of the present invention. FIG. 6B shows an elemental peak obtained by collecting a part of the cobalt and nickel metallized particles a in FIG. 6A and performing elemental analysis with an EDS (Energy Dispersive X-ray Spectrometer) in the embodiment of the present invention. It is a figure which shows. FIG. 6C shows an elemental peak obtained by collecting a part of the cobalt and nickel metallized particles a in FIG. 6A and performing elemental analysis with an EDS (Energy Dispersive X-ray Spectrometer) in the embodiment of the present invention. It is a figure which shows. FIG. 7 is a diagram showing an example of an X-ray diffraction peak showing that the metal of cobalt and nickel is not formed and remains in the oxide form of the positive electrode material in Reference Example 1. FIG. 8 is a diagram showing an example of an X-ray diffraction peak showing that the metal of cobalt and nickel is not formed and remains in the oxide form of the positive electrode material in Reference Example 2. FIG. 9 is a diagram showing an example of the results of analysis by a thermogravimetric differential thermal analyzer for a mixture of carbon and a ternary positive electrode material in a weight ratio of 3: 7 for examining the temperature of heat treatment. Is. FIG. 10 shows an example of the results of analysis by a thermogravimetric differential thermal analyzer on fine-grained products obtained by heat-treating, crushing, and classifying a lithium ion secondary battery for examining the temperature of reheat treatment. It is a figure which shows.

In the method for concentrating valuable metals contained in a lithium ion secondary battery according to the first embodiment of the present invention, the lithium ion secondary battery or its positive electrode material is heat-treated and contains at least one valuable metal of cobalt and nickel. By performing a heat treatment step for forming a lump, at least one of cobalt and nickel is metallized to form a lump of valuable metal having an increased (concentrated) concentration of cobalt and nickel.
As described above, in the first embodiment of the present invention, at least one of cobalt and nickel is concentrated from a lithium ion secondary battery or a positive electrode material thereof containing at least one element of cobalt and nickel as a constituent. Get valuables. At least one of cobalt and nickel is metallized by heat treatment, and then by performing a crushing step and a sorting step, cobalt and nickel and other battery components are sorted, and the concentration of cobalt and nickel is obtained. (Concentrated) valuable resources can be obtained.
Further, in the first embodiment of the present invention, it is preferable to perform the heat treatment in a reducing atmosphere or an inert atmosphere. In the first embodiment of the present invention, by performing the heat treatment in a reducing atmosphere or an inert atmosphere, it becomes easier to form granules containing at least one valuable metal of cobalt and nickel.

Here, metallization refers to compounds such as oxides containing cobalt and nickel, lithium cobaltate (LiCoO ₂ ), lithium cobalt nickelate (LiCo _1/2 Ni _1/2 O ₂ ), ternary systems and NCM. LiNi _x Co _y Mn _z O _2, referred to such a system (x + y + z = 1 ), is _{LiNi x Co y Al z (x} + y + z = 1) cobalt or nickel was present as called such NCA system, changes in the metal (metal) In some cases, metallization means that all of the particles are metallized, while others are partially metallized, and it does not have to be a pure substance. In this way, the metallization of cobalt or nickel means that it is in a state of having a specific gravity and magnetic property close to that of the metal of cobalt or nickel. Further, the metallized cobalt or nickel may be in an alloy state of cobalt or nickel.

In the method for concentrating valuable metals contained in a lithium ion secondary battery according to a second embodiment of the present invention, a lithium ion secondary battery containing at least one element of cobalt and nickel or a positive electrode material thereof is subjected to a heat treatment step and crushing. By performing the classification step and the reheat treatment step, at least one of cobalt and nickel is metallized to form a granular mass of valuable metal having an increased concentration (concentrated) of cobalt and nickel. In the heat treatment step, the positive electrode material existing in the oxide form containing cobalt, nickel, manganese, and lithium is heat-treated while being included in a lithium ion secondary battery cell, a module, or a member of a pack. By performing this heat treatment, cobalt and nickel metals can be efficiently formed while suppressing the combustion consumption of carbon in the lithium ion secondary battery. The cobalt and nickel metals form aggregated particles with oxide particles such as manganese.
When the heat-treated product obtained in the heat treatment step is crushed and classified, the fine-grained product mainly contains cobalt, nickel, manganese, and carbon. By re-heating these powders, the fine cobalt and nickel metals produced in the heat treatment step are used as nuclei, and the cobalt and nickel grow into larger granules (with the fine cobalt and nickel metals). The reduction of the cobalt and nickel oxides that form the agglomerates proceeds to increase the particle size of the fine metal), and the particle size of the agglomerates further increases as the agglomerates melt and bond with each other. As a result, a clear solid-solid interface is formed with oxides such as manganese that originally formed aggregates. This facilitates sorting and concentration.
As described above, in the second embodiment, the cobalt and nickel metals are formed in the heat treatment step, the cobalt and nickel and manganese are separated in the crushing classification step, and the cobalt and metallized in the reheat treatment step. Nickel granules can be grown to form larger granules. Therefore, in the second embodiment, since a large grain mass obtained by metallizing cobalt and nickel can be obtained, the metallized cobalt and nickel can be more easily recovered.

Since this reheat treatment step is performed on the powder, the contact efficiency between the fine metals of cobalt and nickel and the oxide and carbon is improved, and the granules can be formed. In this reheat treatment, carbon combustion occurs in addition to the grain mass formation, and the carbon quality of the product after the reheat treatment can be reduced.
If the heat treatment in the previous step is performed at a temperature lower than 600 ° C., it is difficult for fine metals of cobalt and nickel to be formed by this heat treatment. Therefore, carbon is burnt and consumed before the cobalt and nickel granules are formed, and the cobalt and nickel cannot be made into a sufficiently large granules. Further, cobalt, nickel, manganese and the like still form oxides, and cobalt and nickel exist in a state where it is difficult to separate cobalt and nickel from manganese by physical sorting, and sufficient magnetism cannot be imparted.

In the second embodiment of the present invention, at least one of cobalt and nickel can be obtained by performing at least a part of the burning time in an air atmosphere or an oxidizing atmosphere in at least one of the heat treatment step and the reheat treatment step. The quality of the reduced component of the heat-treated product can be reduced. That is, since the reducing component contained in the heat-treated product is consumed, it is possible to avoid mixing the reducing component into the fine-grained product described later.

(First Embodiment)
Hereinafter, as the first embodiment of the present invention described above, a mode for concentrating valuable metals contained in a lithium ion secondary battery by performing a heat treatment step will be described.

<Heat treatment process>
In the heat treatment step, a lithium ion secondary battery (LIB) or a positive electrode material thereof is heat-treated in a reducing atmosphere or an inert atmosphere to form a granule containing at least one valuable metal of cobalt and nickel. It is a process to make it.
The heat treatment temperature in the heat treatment step is, for example, preferably 600 ° C. or higher and 1,200 ° C. or lower, more preferably 700 ° C. or higher and 1,200 ° C. or lower, and further preferably 750 ° C. or higher and 1,100 ° C. or lower.
By setting the heat treatment temperature to 600 ° C or higher, the metallization of cobalt and nickel can be efficiently promoted, and by setting the heat treatment temperature to 1,200 ° C or lower, the energy and cost required for the heat treatment can be suppressed. Can be done.

The heat treatment time is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 30 minutes or more and 5 hours or less, and more preferably 1 hour or more and 3 hours or less. The heat treatment time may be any time as long as the heat treatment time reaches a desired temperature at which cobalt and nickel are metallized, and the holding time may be such that the time for metallization to proceed can be secured. When the heat treatment time is within a preferable range, it is advantageous in terms of the cost required for the heat treatment.
Therefore, it is preferable to perform the heat treatment at 750 ° C. or higher and 1200 ° C. or lower for 1 hour or longer.

The heat treatment method is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a method using a heat treatment furnace. Examples of the heat treatment furnace include a batch type furnace such as a muffle furnace, a tunnel furnace, a rotary kiln, a fluidized bed furnace, a cupola, and a stoker furnace.

The heat treatment can be performed in an air atmosphere or an oxidizing atmosphere, but can also be performed in a reducing atmosphere or an inert atmosphere.
Examples of the reducing atmosphere include an atmosphere having a low oxygen concentration in which hydrogen, carbon monoxide, and the like are present. Specifically, the atmosphere can be adjusted so that the oxygen concentration is 15% or less.
Examples of the inert atmosphere include an atmosphere composed of nitrogen or argon. In order to metallize cobalt or nickel to facilitate the formation of concentrated granules, a reducing component can be further added.
As described above, in the present invention, when the heat treatment is performed in an inert atmosphere, it is preferable to perform the heat treatment under the condition that the reducing agent is present. By doing so, the metallization of cobalt and nickel can be efficiently promoted.
Examples of the reducing agent include carbon, hydrogen, carbon monoxide, hydrocarbon gas, and hydrocarbon compounds. Further, as the carbon as the reducing agent, for example, carbon derived from the negative electrode material of the lithium ion secondary battery can be used. The reducing component is preferably added in an amount of 0.1% or more by mass ratio with respect to the content of at least one of cobalt and nickel. That is, in the present invention, in the heat treatment step, the heat treatment is performed in a state where 10% by mass or more of carbon is present with respect to the total mass% of at least one of cobalt and nickel contained in the lithium ion secondary battery or its positive electrode material. It is preferable to do so.

Here, in the air, compounds such as oxides containing cobalt and nickel, lithium cobalt oxide (LiCoO ₂ ), lithium cobalt nickel oxide (LiCo _1/2 Ni _1/2 O ₂ ), ternary systems and NCM systems. LiNi _x Co _y Mn _z O _2, referred to as (x + y + z = 1 ) , only heat treatment of the NCA system such as LiNi _x Co _y Al _z called (x + y + z = 1 ) , etc., reactions which cobalt or nickel metallizing proceeds Hateful.
However, even if the oxygen concentration is high to some extent, metallization tends to proceed at high temperatures, and the metallized particles tend to become large. In this case, the heat treatment temperature is preferably 750 ° C to 1200 ° C as described above.
Further, even if the oxygen concentration is high to some extent, for example, if a sufficient reducing agent is present (if a reducing atmosphere can be created), metallization is likely to proceed.

As a method for realizing an atmosphere having a low oxygen concentration (low oxygen atmosphere), for example, a lithium ion secondary battery or a positive electrode material thereof may be housed in an oxygen shielding container and heat-treated.
The material of the oxygen shielding container is not particularly limited as long as it has durability against combustion temperature and internal pressure, and can be appropriately selected depending on the purpose, and examples thereof include iron and stainless steel having a high melting point. Since the lithium ion secondary battery releases gas by combustion of the electrolytic solution inside and the gas pressure rises, it is preferable to provide an opening in the oxygen shielding container. In this case, the opening ratio, which is the ratio of the opening area of the opening to the surface area of the container provided with the opening, is preferably 12.5% or less, more preferably 6.3% or less.
By setting the aperture ratio to 12.5% or less, oxidation of cobalt and nickel due to roasting can be suppressed, and cobalt and nickel can be metallized more efficiently.

Further, by heat-treating the outer case of the lithium ion secondary battery pack, module, or cell, oxygen can be shielded and the metallization of cobalt or nickel can be further promoted. That is, in the present invention, as the oxygen shielding container, for example, an outer case in a pack, module, or cell of a lithium ion secondary battery can be used.
As described above, in the present invention, in the heat treatment step, it is preferable to heat-treat the lithium ion secondary battery in a state of being housed in a case having a melting point equal to or higher than the heat treatment temperature. Exterior cases in packs, modules, or cells can be preferably used.

Further, the cumulative 50% volume particle diameter D ₅₀ of the metallized cobalt and nickel is preferably 1 μm or more, and more preferably 1 μm or more and 5,000 μm or less. When the cumulative 50% volume particle diameter D ₅₀ is 1 μm or more, there is an advantage that separation / concentration is easy in the subsequent sorting step.
The cumulative 50% volume particle diameter D ₅₀ can be measured by, for example, a particle size distribution meter.

Next, after the above-mentioned heat treatment, a heat-treated product (LIB heat-treated product) in which metallized cobalt or nickel and other components are mixed is obtained, but cobalt or nickel, which is a valuable resource for concentration, is simply used. It is preferable to perform a crushing step and a sorting step in order to separate them. This makes it possible to easily sort cobalt and nickel from other battery components (manganese, aluminum, lithium, copper, iron, carbon, etc.).

<Crushing process>
After performing the above heat treatment step, it is preferable to perform a crushing step of crushing the heat-treated product obtained by the heat treatment. In other words, in the present invention, it is preferable to further include a crushing step of crushing the heat-treated product of the lithium ion secondary battery or the positive electrode material thereof obtained by the heat treatment step.

The crushing method in the crushing step is not particularly limited and may be appropriately selected depending on the intended purpose. Examples of the method of crushing by impact include a method of throwing with a rotating striking plate and hitting the collision plate to give an impact, and a method of striking a heat-treated object with a rotating striking element (beater). For example, a hammer crusher or a chain. It can be done with a crusher or the like. Further, a method of hitting a heat-treated object with a ball or rod of ceramic or iron can be mentioned, and this can be performed by a ball mill or a rod mill. Further, as a crushing method by compression, it can be performed by crushing with a twin-screw crusher having a short blade width and a short blade length.

Impact and compression promote the crushing of the active material and the current collector, while the copper in the current collector does not change significantly in morphology and exists in a foil-like or other form. By this crushing, the positive electrode active material containing cobalt and nickel and the current collectors of iron, stainless steel, aluminum, and copper, which are housings, are separated from each other. In the sorting step, a crushed material in a state where these positive electrode active materials and a current collector of iron, stainless steel, aluminum, and copper can be efficiently sorted can be obtained.
Further, by this crushing step, the concentrate of cobalt and nickel is isolated from the heat-treated product (LIB heat-treated product) in which the above-mentioned metallized cobalt and nickel and other components are mixed, and they are in a state of being isolated. It is preferably 2.4 mm or less.

The crushing time in the crushing step is not particularly limited and may be appropriately selected depending on the intended purpose, but the crushing time per 1 kg of the lithium ion secondary battery is preferably 0.1 seconds or more and 30 minutes or less, preferably 0.2. More preferably, it is more than 1 second and 10 minutes or less, and particularly preferably 0.3 seconds or more and 5 minutes or less. By setting the crushing time to 1 second or more and 30 minutes or less, crushing can be performed to a size more suitable for classification.

<Sorting process>
After performing the above crushing step, a sorting step of selecting cobalt and nickel from the crushed material obtained in the crushing step and other positive electrode active material constituents including manganese oxide or aluminum oxide can be performed. preferable. In other words, the present invention preferably includes a sorting step of sorting and recovering a product enriched with at least one of cobalt and nickel from the crushed product of the heat-treated product obtained by the crushing step.
The sorting step is not particularly limited as long as a product in which at least one of cobalt and nickel is concentrated can be sorted and recovered from the crushed product, and can be appropriately selected according to the purpose. It is preferable to include the first sorting step and the second sorting step as shown.

<< First sorting process >>
The first sorting step is a step of classifying the crushed product obtained in the crushing step into coarse-grained products and fine-grained products. The classification method is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a vibration sieve, a multi-stage vibration sieve, a cyclone, a JIS Z8801 standard sieve, a wet vibration table, and an air table.

The sieve mesh (classification point) in the first sorting step is not particularly limited and may be appropriately selected depending on the intended purpose. For example, 0.1 mm or more and 2.4 mm or less are preferable, and 0.6 mm or more and 2. 4 mm or less is more preferable.
By setting the classification point to 2.4 mm or less, it is possible to suppress the mixing of metals derived from the outer container and the copper current collector into the fine-grained product, and it is possible to improve the separation results from cobalt and nickel derived from the active material. .. Further, by setting the mesh size to 0.1 mm or more, the recovery rate of cobalt and nickel derived from the active material in the fine granule product can be improved.
Further, when a sieve is used as a classification method, a crushing accelerator, for example, a stainless ball or an alumina ball is placed on the sieve and sieved to crush small crushed substances adhering to large crushed substances into large pieces. By separating from the object, it is possible to more efficiently separate the large crushed material and the small crushed material. Iron is mainly contained in coarse grain products.
While crushing, the crushed product may be classified into coarse-grained products and fine-grained products as a crushing and classification step (crushing and classification).

<< Second sorting process >>
The second sorting step is a step of separating the fine-grained products obtained in the first sorting step by utilizing at least one difference in magnetism, particle size, and specific gravity. By performing the second sorting step, a valuable metal having an increased concentration (concentrated) of cobalt and nickel can be obtained.

<< Second sorting process using the difference in magnetism (magnetic force sorting) >>
By utilizing the fact that cobalt or nickel is magnetically plated with a single metal, a wet or dry magnetic separation step (dry magnetic separation or wet magnetic separation) can be performed on the fine-grained product obtained in the first sorting step. As a result, valuable resources enriched with metallized cobalt and nickel as magnetic deposits can be concentrated. As non-magnetic products, products enriched with manganese, aluminum, lithium, copper, and carbon can be concentrated.
Further, the second sorting step (magnetic force sorting) utilizing the difference in magnetism can be, for example, the same as the magnetic force sorting step in the first embodiment described above. Therefore, as the second sorting step utilizing the difference in magnetism, for example, a wet magnetic separation step is preferable. Further, the magnetic flux density of the magnet used for magnetic force selection is preferably 0.01 tesla or more and 2 tesla or less. By performing magnetic force sorting using a magnet having a magnetic flux density of 0.02 Tesla or more and 2 Tesla or less, valuable resources having an increased (concentrated) concentration of cobalt and nickel can be obtained.

For example, a ternary positive electrode active material _{(LiNi x Co y Mn z O} 2 (x + y + z = 1)) For the crushing step, and a fine product obtained in the first sorting step by selecting the magnetic force, cobalt And nickel and manganese are separated to obtain valuable resources with increased (concentrated) concentrations of cobalt and nickel.
The magnetic force sorting is preferably wet magnetic force sorting. This is because cross-linking and aggregation due to moisture between particles that occurs in the case of dry magnetic force sorting can be suppressed, the separability of particles is improved, and higher purity cobalt and nickel can be easily obtained.
In the wet magnetic force sorting, a dispersant may be added to the slurry to be applied. The addition of a dispersant can facilitate the separation of cobalt and nickel from other battery components. The amount of the dispersant added is preferably 50 mg / L or more.
It is preferable to perform particle dispersion treatment by ultrasonic waves on the slurry to which the wet magnetic force sorting is applied. By performing this particle dispersion treatment by ultrasonic waves, it is possible to promote the separation of cobalt and nickel from other battery components.

<< Second sorting process using particle size and specific gravity (particle size, specific gravity sorting) >>
The fine-grained products obtained in the first sorting step were further classified according to the particle size and sorted, and the specific gravity sorting was performed to increase the concentrations of metallized cobalt and nickel (metallized). (Concentrated) valuable resources are obtained.
The second sorting step (particle size, specific gravity sorting) using the particle size and the specific gravity is exemplified as an apparatus using the classification method and the specific gravity sorting method, or a composite principle thereof in the first embodiment described above, for example. It can be performed by using various devices.
The classification method, the specific gravity sorting method, or the device utilizing the combined principle thereof is not particularly limited and may be appropriately selected depending on the purpose. For example, a vibrating sieve, a dry cyclone, a turbo classifier, an aerofine classifier. , Micron Classifier, Elbow Jet Classifier, Cliffis CF, Dry Fine Granule Classifier such as Electrostatic Sorter, Hydro Cyclone, Falcon Concentrator, Nelson Concentrator, Multigravity Separator, Laboratory Mineral Separator, Banner Bartless Cross Belt, Kelsey Jig, Examples thereof include a wet fine particle classifier such as an alter jig, an eye classifier, and an upright tubular wet classifier.
It should be noted that there is no particular limitation as long as it is possible to obtain a valuable resource having an increased (concentrated) concentration of the target cobalt and nickel, and the above-mentioned devices can be appropriately combined and used according to the purpose.

For example, in the case of ternary positive electrode active material _{(LiNi x Co y Mn z O} 2 (x + y + z = 1)), crushing step, the granules product obtained in the first sorting step, the cobalt and nickel particles, Valuable resources with increased concentrations of cobalt and nickel can also be obtained by a method of sorting using the difference in specific gravity of manganese oxide particles and a method of classifying using the difference in particle size between the two. ..

It should be noted that not only cobalt and nickel and manganese oxide can be sorted by the above-mentioned magnetic force sorting, sorting by specific gravity, sorting using the difference in particle size, or various sorting by a combination thereof, but also other battery components. It can also be separated from aluminum, lithium, copper, iron, and carbon.

<Fine crushing process>
Further, in the present invention, it is preferable to further perform a fine pulverization step on the fine-grained product obtained in the first sorting step, in other words, before the second sorting step. That is, in the present invention, the second sorting step is performed on the finely pulverized product obtained in the finely pulverized step, including the finely pulverized step of further pulverizing the fine granule product obtained in the first sorting step. Is preferable.
As a result, it is possible to prevent the particles in which cobalt and nickel are metallized (metallized) and other battery constituents from agglomerating or coexisting into a lump, so that the metal of cobalt and nickel and the manganese oxide can be prevented from forming. The single separation of is more accurate.
The fine pulverizer is not particularly limited and may be appropriately selected according to the purpose. For example, a bead mill, a roller mill, a jet mill, a hammer mill, a pin mill, a rotary mill, a vibration mill, a planetary mill, an attritor, etc. Available.

_{The cumulative 50% volume particle diameter D 50} of the finely pulverized product obtained in the fine pulverization step is preferably 75 μm or less, more preferably 0.1 μm or more and 75 μm or less, and further preferably 0.5 μm or more and 53 μm or less. By finely pulverizing the cumulative 50% volume particle diameter D ₅₀ to 75 μm or less, it is possible to promote the separation of cobalt and nickel metals from other constituents.
By a cumulative 50% volume particle diameter D ₅₀ of the finely pulverized material with more than 0.1 [mu] m, cause agglomeration of the cobalt and nickel by moisture due to crosslinking and electrostatic adhesion forces between the particles, and other battery components, It is possible to prevent the separability of the two from being lowered.
The cumulative 50% volume particle diameter D ₅₀ can be measured by, for example, a particle size distribution meter.

<Other processes>
The other steps are not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a valuable resource recovery step and a valuable resource purification step.

(Second embodiment)
Hereinafter, as the second embodiment of the present invention described above, a mode for concentrating the valuable metal contained in the lithium ion secondary battery by performing a heat treatment step, a crushing classification step, and a reheat treatment step will be described. ..
In the second embodiment, the steps other than the heat treatment step and the reheat treatment step in the first embodiment can be the same as those in the first embodiment, and thus the description thereof will be omitted as necessary. I have something to do.

<Heat treatment process>
In the heat treatment step, the lithium ion secondary battery or its positive electrode material is heated to 600 ° C to 1200 ° C.
The heat treatment temperature is preferably 700 ° C. to 1200 ° C., more preferably 750 ° C. to 1100 ° C. from the viewpoint of thermal decomposition of the electrode material. If the heat treatment temperature is less than 600 ° C., the reaction of metallizing cobalt and nickel, which is the main purpose, does not proceed easily. In addition, it becomes difficult to melt and separate the aluminum derived from the housing, which increases the load on the crushing process. If the heat treatment temperature exceeds 1200 ° C., the cost will increase from the viewpoint of energy and economy. Further, if the temperature exceeds 1200 ° C., another problem is that the copper foil melts and it becomes difficult to recover the copper foil.

The heat treatment time can be appropriately selected as long as the molten aluminum can be separated, and is preferably 30 minutes or more and 5 hours or less, and more preferably 1 hour or more and 3 hours or less. The heat treatment time is preferably a heat treatment time at which the reducing component does not remain in the obtained heat treatment product. From the viewpoint of the cost of heat treatment, it is preferable to heat at 750 ° C to 1100 ° C for 1 hour or more.

The heat treatment method is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a method using a heat treatment furnace. Examples of the heat treatment furnace include a batch type furnace such as a muffle furnace, a tunnel furnace, a rotary kiln, a fluidized bed furnace, a cupola, and a stoker furnace.

The heat treatment can be performed in an air atmosphere or an oxidizing atmosphere, but can also be performed in a reducing atmosphere or an inert atmosphere.
Examples of the reducing atmosphere include an atmosphere having a low oxygen concentration in which hydrogen, carbon monoxide, and the like are present. Specifically, the atmosphere can be adjusted so that the oxygen concentration is 15% or less.
Examples of the inert atmosphere include an atmosphere composed of nitrogen or argon. In order to metallize cobalt or nickel to facilitate the formation of concentrated granules, a reducing component can be further added.
As described above, in the present invention, when the heat treatment is performed in an inert atmosphere, it is preferable to perform the heat treatment under the condition that the reducing agent is present. By doing so, the metallization of cobalt and nickel can be efficiently promoted.
Examples of the reducing agent include carbon, hydrogen, carbon monoxide, hydrocarbon gas, and hydrocarbon compounds. Further, as the carbon as the reducing agent, for example, carbon derived from the negative electrode material of the lithium ion secondary battery can be used. The reducing component is preferably added in an amount of 0.1% or more by mass ratio with respect to the content of at least one of cobalt and nickel. That is, in the present invention, in the heat treatment step, the heat treatment is performed in a state where 10% by mass or more of carbon is present with respect to the total mass% of at least one of cobalt and nickel contained in the lithium ion secondary battery or its positive electrode material. It is preferable to do so.

Generally, in the air, compounds such as oxides containing cobalt and nickel, lithium cobalt oxide (LiCoO ₂ ), lithium cobalt nickel oxide (LiCo _1/2 Ni _1/2 O ₂ ), ternary systems, NCM systems, etc. LiNi _x Co _y Mn _z O _2, called (x + y + z = 1 ) , only heat treatment of the NCA system such as LiNi _x Co _y Al _z called (x + y + z = 1 ) , etc., reactions which cobalt or nickel metallizing hardly proceeds ..
However, even in the air, carbon of the negative electrode material may act as a reducing component to facilitate metallization. Further, in the heat treatment in a high temperature range where the heating temperature is 600 to 1200 ° C., metallization tends to proceed, and a small grain mass having a metallized size may be obtained.

When the outer case of the lithium ion secondary battery is made of aluminum or contains aluminum, it is preferable to separate the aluminum derived from the outer case that is melted by the heat treatment from the viewpoint of concentrating cobalt and nickel in the subsequent process. ..

<Crushing classification process>
Next, after the heat treatment step, a heat-treated product (LIB heat-treated product) is obtained. This heat-treated product mainly contains valuable metals such as cobalt and nickel, and other battery components (manganese, aluminum, lithium, copper, iron, carbon, etc.).
Therefore, in order to separate cobalt and nickel, which are valuable metals for concentration purposes, a crushing classification step of crushing and classifying the LIB heat-treated product is performed.

First, as the crushing method, the same crushing method as in the crushing step of the first embodiment described above can be used.
When a grain mass containing metallized cobalt or nickel is formed in the heat treatment step, the crushing method may be to crush the grain mass to the extent that other battery constituents are crushed. In the present invention, for example, a crushing method such as a bead mill, a roller mill, a jet mill, a hammer mill, a pin mill, a rotary mill, a vibration mill, a planetary mill, and an attritor can be appropriately used.

The crushing time can be the same as the crushing time in the crushing step of the first embodiment described above.

Next, by performing classification, fine-grained products containing cobalt and nickel, which constitute the crushed product obtained by the crushing, and coarse-grained products containing exterior case constituents and other electrode constituents are separated.
As a sorting method, it is preferable that the sieve mesh (classification point) is, for example, 0.1 mm to 2.4 mm, and the classification point is more preferably 0.6 mm to 2.4 mm.
By setting the classification point to 2.4 mm or less, it is possible to suppress the mixing of metals derived from the outer container and the copper current collector into the fine-grained product, and it is possible to improve the separation results from cobalt and nickel derived from the active material. .. Further, by setting the mesh size to 0.1 mm or more, the recovery rate of cobalt and nickel derived from the active material in the fine granule product can be improved.

The classification includes, for example, a vibration sieve, a JIS Z8801 standard sieve, a wet vibration table, an air table, a dry cyclone, a turbo classifier, an aerofine classifier, a micron classifier, an elbow jet classifier, a Cliffis CF, and a dry type such as an electrostatic sorter. Wet fine grain classifiers such as fine grain classifiers, hydrocyclones, falcon concentrators, Nelson concentrators, multigravity separators, laboratory mineral separators, banner bartless cross belts, Kelsey jigs, alter jigs, eye classifiers, upright tubular wet classifiers, etc. Can be used.

Further, when a sieve is used as a classification method, a crushing accelerator, for example, a stainless ball or an alumina ball is placed on the sieve and sieved to crush small crushed substances adhering to large crushed substances into large pieces. By separating from the object, it is possible to more efficiently separate the large crushed material and the small crushed material. Iron is mainly contained in coarse grain products.
The crushing classification step may be performed, for example, as a step of classifying the crushed product into coarse-grained products and fine-grained products while crushing.

Further, it is preferable to perform a magnetic force sorting step using a magnetic force on the fine-grained product obtained in the crushing classification step, and perform a reheat treatment step on the magnetically deposited material obtained in the magnetic force sorting step. In other words, it is preferable to magnetically separate the fine-grained product and perform a subsequent reheat treatment step on the obtained magnetized product.
By doing so, the abundance of cobalt and nickel as magnetic particles increases, and grain agglomerates are likely to be formed in the reheat treatment step.

<Reheat treatment process>
Next, in the reheat treatment step, the fine-grained product obtained in the crushing classification step is heated. The heating temperature is preferably 300 ° C. or higher and 1200 ° C. or lower, more preferably 700 ° C. or higher and 1100 ° C. or lower, and particularly preferably 750 ° C. or higher and 1050 ° C. or lower.
As a result, metallized cobalt and nickel granules contained in the fine grain products are formed. The higher the temperature of the reheat treatment, the easier it is for the reaction to form metallized agglomerates to proceed. If the temperature is lower than 300 ° C, the grain mass is not formed, and if the temperature exceeds 1200 ° C., manganese is melted and a substance other than the target substance is caught in the grain mass.
Further, in the reheat treatment step, for example, through the crushing classification step which is the previous step, the powder containing cobalt and nickel and manganese as fine granule products is recovered, and carbon (negative electrode material) which acts as a reducing agent as necessary. The heat treatment is performed again including the origin). Therefore, the contact between the oxide particles containing cobalt, nickel, and manganese and the carbon particles as the reducing agent becomes closer, and the reduction reaction is more likely to occur. As a result, metallization reactions and grain agglomeration are more likely to occur. On the other hand, in the initial heat treatment step, the negative electrode acting as a reducing agent and the positive electrode material containing cobalt and nickel to be reduced are arranged in layers via a separator in the battery configuration. Although various powders and metallization of cobalt and nickel proceed, contact between various powders is unlikely to occur, and the reaction of granule formation is difficult to proceed. Further, in some lithium ion secondary batteries, carbon is added to the positive electrode material as a conductive auxiliary agent, which contributes to the reduction reaction, but recovers cobalt and powder containing nickel and manganese as fine granule products. However, if the heat treatment is performed again, including carbon (derived from the negative electrode material) that acts as a reducing agent as needed, contact is more likely to occur (contact probability is higher), and metallization reaction and grain mass formation are more likely to occur. It is easy to happen.

Here, the grain mass containing metallized cobalt or nickel formed by _{the reheat treatment preferably has a cumulative 50% volume particle diameter D 50} of 1 μm or more, and more preferably 5 μm to 1000 μm. With such a size, it is possible to efficiently recover granules enriched with cobalt or nickel as valuable metals. When the cumulative 50% volume particle diameter D ₅₀ is 1 μm or more, there is an advantage that separation / concentration is easy in the subsequent sorting step. The cumulative 50% volume particle diameter D ₅₀ can be measured by, for example, a particle size distribution meter.
Specifically, it is preferable that the size of the grain mass precursor contained in the fine grain product is 0.01 to 1 μm, and the size of the grain mass obtained by the reheat treatment is 1 to 100 μm.

The heating time in the reheat treatment step can be appropriately selected as long as the cobalt or nickel granules can grow large, preferably 20 minutes or more and 5 hours or less, and more preferably 1 hour or more and 3 hours or less. The heat treatment time is preferably a heating time at which the reducing component does not remain in the obtained heat-treated product.

Further, as the atmosphere used for the reheat treatment, it is preferable to carry out the heat treatment under a reducing atmosphere or an inert atmosphere from the viewpoint of metallization of cobalt and nickel and formation of granules, as in the heat treatment step described above. Further, in the reheat treatment, it is preferable to heat a part of time in an air atmosphere or an oxidizing atmosphere. As a result, the reducing component contained in the heat-treated product is consumed, so that it is possible to avoid mixing with the fine-grained product.

Further, it is preferable to perform a sorting step after the reheat treatment step. As a result, the re-heat-treated product can be recovered separately from the granules in which cobalt, nickel, or one of them is concentrated. On the other hand, other than this grain mass, manganese-enriched products can be recovered.
Typically, a wet or dry magnetic separation step (dry magnetic separation or wet magnetic separation) can be performed by utilizing the fact that cobalt or nickel is magnetized by a single metal.
As a result, the granular mass containing cobalt or nickel formed by metallizing (metallizing) cobalt or nickel formed from the fine granule product in the reheat treatment step can be recovered as a magnetic substance. Manganese, aluminum, lithium, copper and carbon can be recovered as non-magnetic deposits.
Further, the magnetic flux density of the magnet used for magnetic force selection is preferably 0.01 tesla or more and 2 tesla or less. By performing magnetic force sorting using magnets having a magnetic flux density in this range, it is possible to separate grain agglomerates of valuable metals having increased (concentrated) concentrations of cobalt and nickel.

For example, a ternary positive electrode active material _{(LiNi x Co y Mn z O} 2 (x + y + z = 1)) case of the heat treatment product obtained was re-heat-treated fine product in undersize crushing classification step selecting force As a result, the (concentrated) granules with increased concentrations of cobalt and nickel can be recovered as magnetic deposits.
The magnetic force sorting is preferably wet magnetic force sorting. This is because cross-linking and aggregation due to moisture between particles that occurs in the case of dry magnetic force sorting can be suppressed, the separability of particles is improved, and higher purity cobalt and nickel can be easily obtained.
In the wet magnetic force sorting, a dispersant may be added to the slurry to be applied. The addition of a dispersant can facilitate the separation of cobalt and nickel from other battery components. The amount of the dispersant added is preferably 50 mg / L or more.
Further, the slurry to which the wet magnetic force sorting is applied can be subjected to particle dispersion treatment by ultrasonic waves. By performing this particle dispersion treatment by ultrasonic waves, it is possible to promote the separation of cobalt and nickel from other battery components.

Instead of the magnetic force sorting, further classification by particle size and specific gravity sorting can be performed to obtain valuable resources having an increased concentration (concentrated) of metallized cobalt and nickel.
The classification method, the specific gravity sorting method, or the device utilizing the combined principle thereof is not particularly limited and may be appropriately selected depending on the purpose. For example, a vibrating sieve, a dry cyclone, a turbo classifier, an aerofine classifier. , Micron Classifier, Elbow Jet Classifier, Cliffis CF, Dry Fine Granule Classifier such as Electrostatic Sorter, Hydro Cyclone, Falcon Concentrator, Nelson Concentrator, Multigravity Separator, Laboratory Mineral Separator, Banner Bartless Cross Belt, Kelsey Jig, Examples thereof include a wet fine particle classifier such as an alter jig, an eye classifier, and an upright tubular wet classifier.
It should be noted that there is no particular limitation as long as it is possible to obtain a valuable resource having an increased (concentrated) concentration of the target cobalt and nickel, and the above-mentioned devices can be appropriately combined and used according to the purpose.

Prior to the sorting step, the heat-treated product obtained by re-heat-treating the fine-grained product can be crushed again.
As a result, it is possible to reduce the formation of agglomerates containing metallized (metallized) cobalt or nickel and other battery constituents in agglomerates or a mixture. Further, since cobalt or nickel is a metal, it is difficult to atomize by re-crushing, and oxides such as manganese are easily atomized by re-crushing, so impurities other than cobalt or nickel can be selectively pulverized. Therefore, by performing physical sorting such as classification, specific gravity sorting, and magnetic sorting on the re-crushed material, cobalt and nickel can be concentrated in coarse-grained products, heavy products, and magnetic deposits, and fine-grained oxides such as manganese can be concentrated. Can be separated into fine-grained products, light products and non-magnetic deposits. Then, for example, in the case of magnetic force sorting, the separation between cobalt and nickel metals and manganese oxide and the like becomes more accurate.
The re-crushing may be any crushing as long as the crushing is such that the mixed state with other battery components is crushed while retaining the metallized (metallized) granules of cobalt and nickel, and a crusher according to the purpose may be used. It can be selected as appropriate. As the crusher, for example, a bead mill, a roller mill, a jet mill, a hammer mill, a pin mill, a rotary mill, a vibration mill, a planetary mill, an attritor and the like can be used.

<Other processes>
The other steps are not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a valuable metal recovery step and a valuable metal purification step.

An example of a target raw material in the above-mentioned method for concentrating valuable metals contained in the lithium ion secondary battery of the present invention is shown below.

<Lithium-ion secondary battery>
A lithium ion secondary battery is a secondary battery that charges and discharges by moving lithium ions between a positive electrode and a negative electrode. For example, an electrolytic battery containing a positive electrode, a negative electrode, a separator, an electrolyte, and an organic solvent. Examples thereof include a battery cell provided with a liquid and an outer container which is a battery case for accommodating a positive electrode, a negative electrode, a separator and an electrolytic solution, a module in which a plurality of the liquids are connected, and a battery pack in which the modules are housed in the container.

The shape, structure, size, material, etc. of the lithium ion secondary battery are not particularly limited and can be appropriately selected according to the purpose. Examples of the shape of the lithium ion secondary battery include a laminated type, a cylindrical type, a button type, a coin type, a square type, and a flat type.

<Positive electrode, positive electrode current collector, and positive electrode active material>
The positive electrode is not particularly limited as long as it has a positive electrode material on the positive electrode current collector, and can be appropriately selected depending on the intended purpose. The shape of the positive electrode is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a flat plate shape and a sheet shape.

The shape, structure, size, material, and the like of the positive electrode current collector are not particularly limited, and can be appropriately selected according to the purpose. Examples of the shape of the positive electrode current collector include a foil shape. Examples of the material of the positive electrode current collector include stainless steel, nickel, aluminum, copper, titanium, and tantalum.

The positive electrode material is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a positive electrode material containing at least a positive electrode active material containing a rare valuable metal and, if necessary, a conductive agent and a binder resin. And so on. The rare valuable metal is not particularly limited and may be appropriately selected depending on the intended purpose, but it is preferable that at least one of cobalt and nickel is contained.

As the positive electrode active material, for example, lithium cobaltate (LiCoO _2), lithium cobalt nickel oxide _{(LiCo 1/2 Ni 1/2 O 2)} , LiNi x Co y Mn z O 2 , referred to as ternary or NCM system (x + y + z = 1 ), LiNi x Co y Al z (x + y + z = 1) , referred to as NCA system, or the like of these composites.

<Negative electrode, negative electrode current collector, and negative electrode active material>
The negative electrode is not particularly limited as long as it has a negative electrode material on the negative electrode current collector, and can be appropriately selected depending on the intended purpose.
The shape of the negative electrode is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a flat plate shape and a sheet shape.
The shape, structure, size, material, and the like of the negative electrode current collector are not particularly limited, and can be appropriately selected according to the purpose.
Examples of the shape of the negative electrode current collector include a foil shape.
Examples of the material of the negative electrode current collector include stainless steel, nickel, aluminum, copper, titanium, and tantalum. Of these, copper is preferred.

The negative electrode material is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a negative electrode material containing at least a negative electrode active material and, if necessary, a conductive agent and a binder resin.

The negative electrode active material is not particularly limited and may be appropriately selected depending on the intended purpose. For example, carbon material such as carbon black, graphite, carbon fiber, metal carbide, organic substance, carbon dioxide of organic substance, titanate, silicon, or Examples thereof include these composites.
The carbon material as the negative electrode active material can act as a reducing agent during the heat treatment and promote the metallization of cobalt and nickel.

<Exterior container>
The material of the outer container (housing) of the lithium ion secondary battery is not particularly limited and may be appropriately selected depending on the intended purpose. For example, aluminum, resin (plastic), stainless steel, iron, or other alloys. Made of, etc.

Hereinafter, examples of the present invention will be described, but the present invention is not limited to these examples.

(Example 1)
As a raw material (target sample) to be treated, a battery pack of 295 kg of a used in-vehicle lithium ion secondary battery was prepared. Positive electrode material contained in the battery is ternary positive electrode active material, composition _{(LiNi x Co y Mn z O} 2 (x + y + z = 1), x = 0.33, y = 0.33, z = 0 .33). The negative electrode active material is carbon. The iron outer case of the battery pack was used as the oxygen shielding container.
This was heat-treated at 750 ° C. for 1 hour in the same state (whole) using a burner type fixed bed furnace (industrial furnace). This heat-treated product was crushed using a hammer crusher (manufactured by Makino Co., Ltd., HC-20), and then classified with a 1.2 mm vibrating sieve to recover 60 kg of fine-grained products under the sieve. When the composition of the fine granule product was analyzed, the composition of the fine granule product was 12% by mass of cobalt, 12% by mass of nickel, and 11% by mass of manganese.
Scanning electron microscope (SEM) photographs of this fine-grained product are shown in FIGS. 1 and 2. In FIG. 1, in the region surrounded by a circle, the portion that looks like a bright (white) dot is a metallized portion of cobalt and nickel. As shown in FIG. 1, at this point, fine particles in which cobalt and nickel are metallized can be confirmed on the surface of the positive electrode material particles. At this point, the metallized particle size of cobalt and nickel is small, and most of the particles are less than 1 μm. Further, FIG. 2 is an SEM photograph of a coarse-grained product taken from a different field of view from FIG. 1, in which cobalt and nickel metallized are distributed in the region surrounded by the dotted line, and are surrounded by a solid line. Manganese oxide is distributed in the region. As shown in FIGS. 1 and 2, it was confirmed that the cobalt and nickel particles were present as particles separated from the manganese oxide in the fine-grained product.
In Example 1, although the inside of the burner type fixed bed furnace has an oxidizing atmosphere, the iron outer case of the battery pack is used as it is as the oxygen shielding container, and the negative electrode active material of the lithium ion secondary battery is used. Since the carbon used acts as a reducing agent, the atmosphere inside the outer case becomes a reducing atmosphere. Here, in Example 1, the heat treatment was performed in a state where the amount of carbon as a reducing agent was 135% by mass with respect to the total amount of cobalt and nickel contained in the lithium ion secondary battery.

Next, a part of the obtained fine-grained product was collected, and the atmosphere was set to a reducing atmosphere (a state in which carbon derived from the negative electrode active material was present as a reducing agent by putting it in a container and covering it) at 1000 ° C. for 1 hour. By performing heat treatment (reheat treatment), a reheated product was obtained. The amount of carbon contained in the fine-grained product was heat-treated in a state where 135% by mass of carbon was present with respect to the total amount of cobalt and nickel contained in the lithium ion secondary battery. As a result, it was confirmed that the fine particles in which the cobalt and nickel contained in the fine grain products were metallized (metallized) became a grain mass.
That is, a part of each of the bright white-looking region (solid line) and the gray-looking region (dotted line) shown in the photograph of the scanning electron microscope (SEM) in FIG. 3A is sampled and EDS (energy dispersive type) is taken. Elemental analysis was performed with an X-ray spectroscope).
As a result, it was found that the region surrounded by the solid line contained a large amount of cobalt and nickel from the peak obtained in the spectrum 179 as shown in FIG. 3B. On the other hand, the region surrounded by the dotted line was found to contain a large amount of manganese and oxygen from the peak obtained in the spectrum 180 as shown in FIG. 3C.
As described above, in the region surrounded by the solid line in FIG. 3A, metallized granules mainly composed of cobalt and nickel are formed, and in the region surrounded by the dotted line in FIG. 3A, manganese due to manganese and oxygen is formed. It can be seen that the oxide is formed. Further, in the electron microscope image shown in FIG. 3A, it can be seen that the grain mass grows into a mass of about 1 to 10 μm.
In addition, FIG. 3D shows an SEM photograph observing the state after 1 hour of heat treatment. It was confirmed that grain agglomerates were formed even after 1 hour of heat treatment.

Next, the magnetic flux density: 1500 G (0.15 tesla), using a drum-type magnetic separator (WDL8 lab model manufactured by Nippon Elise Magnetics Co., Ltd.), was applied to the reheated product obtained by performing the reheat treatment. Wet magnetic separation was performed at a drum rotation speed of 30 rpm, a solid-liquid ratio of 10%, and a slurry supply rate of 2 L / min to recover magnetically-plated and non-magnetically-coated slurries. Further, in the wet magnetic separation for the reheat-treated product, a dispersant was added to the slurry of the reheat-treated product so as to be about 6% with respect to the amount of carbon, and then the particle dispersion treatment was performed by ultrasonic waves.
As a result, a grain mass containing metallized cobalt and nickel as a magnetic substance was obtained. It was confirmed that manganese oxide and the like were separated from the non-magnetic material.

FIG. 4A shows a scanning electron microscope (SEM) photograph of the fine grain product before wet magnetic force sorting. In FIG. 4A, it was confirmed that the region surrounded by the solid line was a grain mass of cobalt and nickel, and the region surrounded by the dotted line was an oxide of manganese.
That is, a part was sampled for each of the brighter and whiter-looking region (solid line) and the gray-darker-looking region (dotted line) shown in the electron microscope image of FIG. 4A, and elemental analysis was performed by EDS.
As a result, it was found that the region surrounded by the solid line was a cobalt and nickel grain mass from the peak obtained in the spectrum 171 as shown in FIG. 4B. On the other hand, the region surrounded by the dotted line was found to be a manganese oxide from the peak obtained in the spectrum 173 as shown in FIG. 4C. It can be inferred that the particles darker than the dotted line region of the electron microscope image are carbon.

FIG. 5A shows a scanning electron microscope (SEM) photograph of the fine-grained product after wet magnetic force sorting. In FIG. 5A, it was confirmed that the region surrounded by the solid line was a grain mass of cobalt and nickel, and the region surrounded by the dotted line was an oxide of manganese.
That is, a part was sampled for each of the brighter and whiter-looking region (solid line) and the gray-darker-looking region (dotted line) shown in the electron microscope image of FIG. 5A, and elemental analysis was performed by EDS.
As a result, it was found that the region surrounded by the solid line was a cobalt and nickel grain mass from the peak obtained in the spectrum 136 as shown in FIG. 5B. On the other hand, the region surrounded by the dotted line was found to be a manganese oxide from the peak obtained in the spectrum 135 as shown in FIG. 5C. It can be inferred that the particles darker than the dotted line region of the electron microscope image are carbon.

From the above, as shown in FIG. 4A, cobalt and nickel granules and manganese oxides are both found at the same frequency in the fine particles before magnetic sorting, as shown in FIG. 5A. It can be seen that the proportion of the oxide of manganese decreased after the magnetic selection, and the proportion of the cobalt and nickel granules increased as compared with that before the magnetic selection.

As described above, in Example 1 of the present invention, metallized cobalt and nickel could be concentrated from the lithium ion secondary battery.

(Example 2)
In Example 2, the product after the reheat treatment was further pulverized (finely pulverized), and then wet magnetic separation was further carried out in the same manner as in Example 1 to obtain a concentrate of cobalt and nickel.
More specifically, in Example 2, particles which are lumps of metal and oxide in the fine-grained product were finely pulverized using a vibration mill (RS200, manufactured by Lecce). The cumulative 50% volume particle diameter D ₅₀ of the finely pulverized material was 3.9 μm.
By finely pulverizing, the metal of cobalt or nickel and the manganese oxide could be separated more accurately as a simple substance. The simple substance separation in this case means a state in which the metal particles of cobalt and nickel and the oxide particles of manganese are separately present separately.

FIG. 6A shows an SEM photograph taken of an example of finely pulverized particles which are lumps of metal and oxide in a fine grain product. In FIG. 6A, the particles a in which cobalt and nickel are metallized are distributed in the region surrounded by the dotted line, and the manganese oxide particles b are distributed in the region surrounded by the solid line.
FIG. 6B is a diagram showing the results of elemental analysis by collecting a part of the particles a in which cobalt and nickel are metallized in FIG. 6A. FIG. 6C is a diagram showing the results of elemental analysis by collecting a part of the manganese oxide particles b in FIG. 6A and performing elemental analysis with an EDS (energy dispersive X-ray spectroscope).
As shown in FIGS. 6B and 6C, it was confirmed that cobalt and nickel were concentrated in the cobalt and nickel metallized particles a, and manganese oxide was concentrated in the manganese oxide particles b. did it.
In Example 2, in the same manner as in Example 1, wet magnetic separation was performed using a drum-type magnetic separator, and the magnetically-plated and non-magnetic-separated slurry were recovered to obtain metallized cobalt and nickel as the magnetic-separated material. The contained granules were recovered, and manganese oxide and the like were recovered as non-magnetic particles.

(Example 3)
In Example 3, the battery pack of the lithium ion secondary battery was heat-treated, crushed, and sieved in the same manner as in Example 1 to obtain fine-grained products under the sieve. Next, in Example 3, the obtained fine-grained product was subjected to wet magnetic separation (first wet magnetic separation before reheat treatment) under the same conditions as in Example 1 to obtain a magnetic material. Then, in Example 3, the obtained magnetic deposit was reheat-treated under the same conditions as in Example 1, and the heat-treated product obtained by the re-heat treatment was further subjected to wet magnetic separation (second time, wet in Examples 1 and 2). (Corresponding to magnetic separation) was carried out to obtain a magnetically coated material. Here, in this second wet magnetic separation, a magnetized material and a non-magnetized material slurry were sorted using a drum type magnetic separator under the same conditions as in Example 1. When the obtained magnetic material was analyzed, cobalt and nickel were concentrated in the magnetic material.
Table 1 shows the grades of cobalt, nickel, and manganese of the magnetically and non-magnetically deposited materials obtained by the second wet magnetic separation in Example 3, and the recovery rates of cobalt, nickel, and manganese by the wet magnetic separation.

(Example 4)
In Example 4, the cobalt and nickel concentrates (second time) were the same as in Example 3 except that the reheat treatment temperature was set to 850 ° C. and the reheat treatment product was finely pulverized under the same conditions as in Example 2. (Magnetic material in wet magnetic separation) was obtained. Table 1 shows the grades of cobalt, nickel, and manganese of the magnetically and non-magnetically deposited materials obtained by the second wet magnetic separation in Example 4, and the recovery rates of cobalt, nickel, and manganese by the wet magnetic separation.
When the state of the magnetic substance obtained by the second wet magnetic separation in Example 3 and the state of the magnetic substance obtained by the second wet magnetic separation in Example 4 were observed and compared by SEM, in Example 3, cobalt and nickel grown by reheat treatment were compared. Some parts of the granules and manganese oxide were observed to be aggregated and present. On the other hand, in Example 4, the aggregated state of the physical cobalt and nickel metals and the manganese oxide could be more sufficiently eliminated by crushing the product after the reheat treatment. From this, it was found that in Example 4, the separability of cobalt, nickel and manganese in wet magnetic separation was further improved as compared with Example 3. That is, in Example 4, more cobalt and nickel could be recovered on the magnetized surface side, and more manganese could be recovered on the non-magnetically coated side as compared with Example 3.

(Examples 5 to 7)
In Examples 5 to 7, Example 4 except that the reheat treatment temperature (850 ° C. or 1000 ° C.) and the reheat treatment time (1 hour or 4 hours) were changed to the temperature and time conditions shown in Table 1. In the same manner as above, concentrates of cobalt and nickel were obtained. Table 1 shows the grades of cobalt, nickel, and manganese of the magnetically and non-magnetically deposited materials obtained by the second wet magnetic separation in Examples 5 to 7, and the recovery rates of cobalt, nickel, and manganese by the wet magnetic separation. From the results of Examples 5 to 7, it was found that it is more preferable that the reheat treatment has a high temperature and a long heat treatment time.

(Examples 8 and 9)
In Example 8, concentrates of cobalt and nickel were obtained in the same manner as in Example 4, except that the fine-grained products under the sieve were not reheat-treated.
In Example 9, concentrates of cobalt and nickel were obtained in the same manner as in Example 4, except that the fine-grained products under the sieve were not both reheat-treated and finely ground by a vibration mill.
Table 1 shows the grades of cobalt, nickel, and manganese of the magnetically and non-magnetically coated materials obtained by the second magnetic force selection in Examples 8 and 9, and the recovery rates of cobalt, nickel, and manganese by the magnetic force selection. From the results of Examples 4, 8 and 9, it was confirmed that the recovery rate and quality of cobalt and nickel in the magnetically coated material were further improved by performing the reheat treatment. In addition, it was confirmed that fine pulverization using a vibration mill or the like is also effective in improving the recovery rate and quality of cobalt and nickel in magnetic objects. From the above results, it was confirmed that in the present invention, it is more preferable to perform reheat treatment and fine pulverization in combination.

(Example 10)
In Example 10, cobalt and nickel are also used in the positive electrode material product itself in the lithium ion secondary battery and in the lot-out positive electrode material discharged in the manufacturing process of the lithium ion secondary battery by the same method as in the above-described embodiment. since concentrated, to make sure that can separate manganese cathode material (reagent ternary positive electrode material used in the lithium ion secondary battery _{(LiNi x Co y Mn z O} 2 (x + y + z = 1), x = 0. 33, y = 0.33, z = 0.33))) was processed.
In Example 10, first, carbon is added to the above-mentioned positive electrode material, and the temperature is 1000 ° C. for 1 hour in a reducing atmosphere (a state in which carbon as a reducing agent is present after being placed in a container and then covered with a lid). Heat treatment (corresponding to the reheat treatment in Examples 1 to 10) was performed in. When the positive electrode material after the heat treatment was confirmed in Example 10, it was confirmed that cobalt and nickel formed metal grain lumps.
Then, in Example 10, the positive electrode material after the heat treatment is subjected to wet magnetic separation (selection of a magnetically bonded substance and a non-magnetically bonded slurry using a drum type magnetic separator) in the same manner as in Example 2. rice field. Subsequently, when the obtained magnetic deposit was observed, it was confirmed that cobalt and nickel were concentrated.

(Examples 11 to 14)
In Examples 11 to 14, a lithium ion secondary battery pack using LMO (a manganese-based positive electrode material using lithium manganate) as a positive electrode material was treated.
Further, in Example 11, the wet magnetic separation (the first wet magnetic separation in Example 9) was performed on the fine-grained products selected under the sieve of the crushed product after the heat treatment of the lithium ion secondary battery pack, and further. Concentrates of cobalt and nickel in the same manner as in Example 9 except that the particle dispersion treatment by ultrasonic waves and the addition of the dispersant were not performed when the wet magnetic separation was performed on the reheat-treated product obtained by the reheat treatment. Got
In Example 12, the fine particle products sorted under the sieve of the crushed product after the heat treatment of the lithium ion secondary battery pack were not subjected to wet magnetic separation (the first wet magnetic separation in Example 9), and further reheated. A cobalt and nickel concentrates were obtained in the same manner as in Example 9 except that the particle dispersion treatment by ultrasonic waves was not performed when the wet magnetic separation was performed on the reheat-treated product obtained in the above.
In Example 13, the fine-grained products sorted under the sieve of the crushed product after the heat treatment of the lithium ion secondary battery pack were not subjected to wet magnetic separation (the first wet magnetic separation in Example 9), and further reheat-treated. A cobalt and nickel concentrates were obtained in the same manner as in Example 9 except that a dispersant was not added when the wet magnetic separation was performed on the reheat-treated product obtained in the above-mentioned procedure.
In Example 14, except that wet magnetic separation (first wet magnetic separation in Example 9) is not performed on the fine-grained products sorted under the sieve of the crushed product after the heat treatment of the lithium ion secondary battery pack. Concentrates of cobalt and nickel were obtained in the same manner as above.

From the results of Examples 11 to 14, the effects of each of the particle dispersion treatment by ultrasonic waves and the addition of the dispersant on the quality of cobalt and nickel obtained by wet magnetic separation were evaluated. Table 1 shows the grades of cobalt, nickel, and manganese of the magnetically-coated and non-magnetic-separated materials obtained by wet magnetic separation in Examples 11 to 14, and the recovery rates of cobalt, nickel, and manganese by wet magnetic separation. From this result, it was confirmed that it is more preferable to use ultrasonic waves and a dispersant in combination in order to improve the quality of cobalt and nickel obtained by wet magnetic separation.

(Example 15)
In Example 15, the fine-grained products selected under the sieve of the crushed product obtained by crushing and classifying the heat-treated product obtained by heat treatment were subjected to a vibration mill under the same conditions as in Example 8. Concentrates of cobalt and nickel were obtained in the same manner as in Example 14, except that they were finely ground.
Table 1 shows the grades of cobalt, nickel, and manganese of the magnetically and non-magnetically deposited materials obtained by wet magnetic separation in Example 15, and the recovery rates of cobalt, nickel, and manganese by wet magnetic separation. In Example 15, the grades of cobalt and nickel in the magnetic material were further improved as compared with Example 14.

(Example 16)
In Example 16, a lithium ion secondary battery pack using LMO as a positive electrode material is targeted for treatment, and wet magnetic sorting (wet magnetic sorting) for fine-grained products sorted under the sieve of the crushed product after heat treatment of the lithium ion secondary battery pack. Concentrates of cobalt and nickel were obtained in the same manner as in Example 7 except that the first wet magnetic separation in Example 7) was not performed.
Table 1 shows the grades of cobalt, nickel, and manganese in the magnetically and non-magnetically separated materials obtained by wet magnetic separation in Example 16, and the recovery rates of cobalt, nickel, and manganese by wet magnetic separation. In Example 16, the grades of cobalt and nickel were the highest as compared with Examples 11 to 15. From this result, as in Example 7, reheat treatment was performed in a reducing atmosphere, and then finely pulverized by a vibration mill, and then the finely pulverized heat treated product was subjected to particle dispersion treatment by ultrasonic waves and a dispersant. It was found that it is preferable to concentrate cobalt and nickel by performing wet magnetic separation using the above.

(Examples 17 and 18)
In Example 17, a lithium ion secondary battery pack using LMO as a positive electrode material was heat-treated and crushed under the same conditions as in Example 1, and dust containing cobalt and nickel generated during crushing was collected. Was finely pulverized with a vibration mill, and then wet magnetic separation was performed in the same manner as in Example 1 to obtain a concentrate of cobalt and nickel.
Further, in Example 18, a lithium ion secondary battery pack using LMO as a positive electrode material is heat-treated and crushed under the same conditions as in Example 1, and dust containing cobalt and nickel generated during crushing is collected. The obtained product was subjected to the treatment after the reheat treatment in the same manner as in Example 2 except that the reheat treatment was performed with the reheat treatment time set to 4 hours to obtain a concentrate of cobalt and nickel.
Table 1 shows the grades of cobalt, nickel, and manganese of the magnetically and non-magnetically separated materials obtained by wet magnetic separation in Examples 17 and 18, and the recovery rates of cobalt, nickel, and manganese by wet magnetic separation. From these results, it was confirmed that the dust collectors generated during crushing also contained cobalt and nickel metals, and these could be concentrated. In addition, it was confirmed that the cobalt and nickel grains could be enlarged by the reheat treatment, and the cobalt and nickel could be more concentrated.

(Reference example 1)
In Reference Example 1, the same treatment as in Example 10 was performed except that the heat treatment was performed in an oxidizing atmosphere, and it was confirmed whether or not cobalt and nickel metals were produced. Fines product X-ray diffractometer (Rigaku, UltimaIV) after heat treatment was confirmed _{by, LiNi x Co y Mn z O} 2 (x + y + z = 1), x = 0.33, y = 0.33, Only the peak of z = 0.33) was confirmed, and the peak of cobalt and nickel metals was not confirmed. That is, it was confirmed that cobalt and nickel were oxidized and remained as oxides, metal agglomerates were not formed, and sorting by magnetic force was not possible.
FIG. 7 shows an X-ray diffraction peak (spectrum) showing that in Reference Example 1, the metal of cobalt and nickel is not formed and remains in the form of the oxide of the positive electrode material.

(Reference example 2)
In Reference Example 2, the same treatment as in Example 10 was performed except that the heat treatment temperature during the heat treatment was set to 550 ° C., and it was confirmed whether or not cobalt and nickel metals were produced. Fines product X-ray diffractometer (Rigaku, UltimaIV) after heat treatment was confirmed _{by, LiNi x Co y Mn z O} 2 (x + y + z = 1), x = 0.33, y = 0.33, A peak of z = 0.33) and a peak of carbon were confirmed, and a peak of cobalt and nickel metals was not confirmed. That is, it was confirmed that the metal agglomerates were not formed (or almost not formed) and could not be sorted by magnetic force.
FIG. 8 shows an X-ray diffraction peak (spectrum) showing that in Reference Example 2, the metal of cobalt and nickel is not formed and remains in the form of the oxide of the positive electrode material.

In addition, Tables 2 to 5 below show a summary of the processing conditions and the like of each embodiment.

(Examination of heat treatment temperature)
Regarding the heat treatment temperature of the battery pack, it was confirmed by a thermogravimetric differential thermal analyzer (manufactured by Rigaku Co., Ltd.) that cobalt and nickel metals were produced at 750 ° C to 1200 ° C.
Specifically, a mixture of carbon and a ternary positive electrode material (cobalt, nickel, manganese having a molar ratio of 1: 1: 1) at a ratio of 3: 7 was analyzed by a thermogravimetric differential thermal analyzer. The measurement conditions were a nitrogen atmosphere and a heating rate of 20 ° C./min.

FIG. 9 shows the results of analysis by a thermogravimetric differential thermal analyzer for a mixture of carbon and a ternary positive electrode material in a weight ratio of 3: 7 for examining the temperature of the heat treatment. In FIG. 7, the vertical axis shows the change in mass (Weight: TG curve) and the temperature difference (Heat Flow; DTA curve), and the horizontal axis shows the temperature.
In the example shown in FIG. 9, it can be seen that endothermic process starts around 400 ° C. and weight loss occurs around 750 ° C. The state in which the weight loss and the endothermic reaction occur at the same time is characteristic of the reduction reaction. This suggests that a reduction reaction with carbon of the positive electrode material reagent used for analysis has occurred. The following reactions can be considered as the reactions that are considered to occur in this example.
2LiMO ₂ + C → Li ₂ O + 2MO + CO
MO + C → M + CO
(Here, M is a composite of cobalt, nickel, manganese, or any simple substance)
From this, it is considered preferable to heat-treat at 750 ° C. or higher in order to promote the metallization of cobalt and nickel by utilizing the reduction reaction by contact with carbon.

(Examination of temperature of reheat treatment)
Next, the temperature of the reheat treatment in which the metallization of cobalt and nickel occurs was verified by the above thermogravimetric differential thermal analyzer. In this verification, a lithium-ion secondary battery as a sample (target) was heat-treated, crushed, and sieved (classified) to obtain fine-grained products sorted under a sieve, and a thermal weight differential was obtained. It was used for a thermal analyzer. As in the above-mentioned embodiment, the measurement atmosphere at this time is not a condition in which there is no air completely, assuming a reduction atmosphere by the lid, and oxygen is not positively supplied, but oxygen is supplied around the sample. Was present, and the coexistence of carbon as a powder created a reducing atmosphere, and the measurement was performed in an air atmosphere. The heating rate was 20 ° C./min.

FIG. 10 shows the results of analysis by a thermogravimetric differential thermal analyzer on fine-grained products obtained by heat-treating, crushing, and classifying a lithium ion secondary battery for examining the temperature of reheat treatment. ..
As shown in FIG. 10, it was confirmed that the weight loss and the exothermic reaction occurred from around 300 ° C., and the carbon burned. At this time, the cobalt and nickel compounds were reduced by CO (carbon monoxide) generated by combustion, and the metallization reaction proceeded. The following reactions can be considered as the reactions that are considered to occur in this example.
2C + O ₂ → 2CO
MO + CO → M + CO ₂
(Here, M is a composite of cobalt, nickel, manganese, or any simple substance)
From this, it is considered preferable to perform the reheat treatment at 300 ° C. or higher.

Claims (15)

In a lithium ion secondary battery containing at least one element of cobalt and nickel and manganese, a lithium ion secondary battery or a positive electrode material thereof is treated to concentrate a valuable metal containing at least one element of cobalt and nickel. It is a method of concentrating the contained valuable metals.
A heat treatment step of heating the lithium ion secondary battery or its positive electrode material to 600 ° C to 1200 ° C.
A crushing and classifying step of crushing and classifying the heat-treated product obtained in the heat treatment step,
A reheat treatment step of heating the fine granule product obtained in the crushing classification step to 700 ° C. or higher and 1100 ° C. or lower again to form a granule containing at least one valuable metal of cobalt and nickel while keeping manganese in an oxidized state. ,
A method for concentrating valuable metals contained in a lithium ion secondary battery, which comprises. The method for concentrating valuable metals contained in a lithium ion secondary battery according to claim 1, wherein the negative electrode material in the lithium ion secondary battery contains carbon. The lithium according to any one of claims 1 to 2, which comprises a sorting step of sorting and recovering a product in which at least one of cobalt and nickel is concentrated from the reheat-treated product obtained in the reheat treatment step. A method for concentrating valuable metals contained in an ion secondary battery. The method for concentrating a valuable metal contained in a lithium ion secondary battery according to claim 3, wherein in the sorting step, a product enriched with at least one of cobalt and nickel and a product enriched with manganese are recovered. The lithium ion secondary battery according to any one of claims 3 to 4, wherein the sorting step is a step of performing separation using at least any difference in magnetism, particle size, and specific gravity. Method for concentrating valuable metals. The lithium ion secondary battery according to any one of claims 1 to 5, wherein in the heat treatment step, the lithium ion secondary battery is housed in a case containing aluminum and the aluminum derived from the case is separated at the time of heating. A method for concentrating valuable metals contained in. The lithium ion according to any one of claims 1 to 6, wherein in the crushing classification step, crushing is performed by impact, shearing or compression, and classification is performed using a sieve having a sieve mesh of 0.1 mm to 2.4 mm. A method for concentrating valuable metals contained in a secondary battery. Cumulative 50% volume particle diameter D in the grain mass containing at least one metal of cobalt and nickel in the reheat treatment step. ₅₀ The method for concentrating valuable metals contained in a lithium ion secondary battery according to any one of claims 1 to 7, wherein the thickness is 1 μm or more. The method for concentrating valuable metals contained in a lithium ion secondary battery according to claim 3, wherein the sorting step is a magnetic force sorting step, and the magnetic flux density of the magnet in the magnetic force sorting step is 0.01 tesla or more and 2 tesla or less. The method for concentrating valuable metals contained in a lithium ion secondary battery according to claim 9, wherein the magnetic force sorting step is wet magnetic force sorting, and a dispersant of 50 mg / L or more is added to the slurry to be applied. The method for concentrating valuable metals contained in a lithium ion secondary battery according to claim 10, wherein the slurry applied by the wet magnetic force sorting is subjected to particle dispersion treatment by ultrasonic waves. The valuable value contained in the lithium ion secondary battery according to any one of claims 1 to 11, wherein a reducing component is added to form a reducing atmosphere in at least one of the heat treatment step and the reheat treatment step. Metal concentration method. Any of claims 1 to 12, wherein in the heat treatment step or the reheat treatment step, a part of the heat treatment time is heated in an air atmosphere or an oxidizing atmosphere to reduce the quality of the reduced component of the heat-treated product or the reheat-treated product. The method for concentrating valuable metals contained in a lithium ion secondary battery according to one item. The method for concentrating valuable metals contained in a lithium ion secondary battery according to claim 3, wherein a re-crushing step of re-crushing the heat-treated product is performed after the re-heat treatment step and before the sorting step. Claims 1 to 14 include performing a magnetic force sorting step using a magnetic force on the fine-grained product obtained in the crushing classification step, and performing the reheat treatment step on the magnetically deposited material obtained in the magnetic force sorting step. The method for concentrating valuable metals contained in the lithium ion secondary battery according to any one of the above.

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