Methods for concentrating valuable metals contained in lithium-ion secondary batteries

Abstract

A method for concentrating valuable metals contained in a lithium-ion secondary battery is provided, comprising: processing a lithium-ion secondary battery or its positive electrode material containing at least one element selected from cobalt and nickel to concentrate at least one valuable metal selected from cobalt and nickel; and a heat treatment step, which involves heat-treating the aforementioned lithium-ion secondary battery or its positive electrode material to form granules containing at least one valuable metal selected from cobalt and nickel.

Description

Method for Concentrating Valuable Metals Contained in Lithium-Ion Secondary Batteries The present invention relates to a method for concentrating valuable metals contained in lithium-ion secondary batteries. Compared with conventional lead-acid batteries and nickel-cadmium secondary batteries, etc., lithium-ion secondary batteries are secondary batteries that are lighter, have a larger capacity, and a higher electromotive force, and they have been used as secondary batteries for personal computers, electric vehicles, portable devices, etc. For example, in the positive electrode of a lithium-ion secondary battery, valuable metals such as cobalt and nickel are used as lithium cobaltate (LiCoO 2 ), ternary cathode active materials (LiNi x Co y Mn z O 2 (x + y + z = 1)), etc. Since the use of lithium-ion secondary batteries is expected to continue to expand in the future, from the perspective of resource recycling, it is desirable to concentrate valuable metals such as cobalt and nickel from defective products generated during the manufacturing process of lithium-ion secondary batteries and lithium-ion secondary batteries discarded due to the lifespan of the used devices and batteries. For example, regarding the technology for recovering valuable metals from waste materials of lithium-ion secondary batteries, a method for recovering metal compounds for use as cathode materials has been proposed. In this method, the waste materials of the secondary battery are heated in a gas stream containing oxygen at 300 to 500 °C, and after separating and removing the metal foil, the recovered material is heated again in a gas stream containing oxygen at 500 to 650 °C to remove combustible substances (see Patent Document 1). In this method, two-stage thermal decomposition treatment is carried out. In the first stage, 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. Also, in the second stage after the metal foil is separated and removed, by decomposing graphite, the sintering phenomenon that causes the particle size of the recovered metal compound to become larger can be suppressed. Also, for example, a method has been proposed in which a lithium-ion battery enclosed in an aluminum case is heated under low-temperature conditions of 400 to 550 °C, and the sieved battery powder after pulverization and classification is heated under high-temperature conditions of 550 to 700 °C to effectively remove aluminum and convert valuable metals such as cobalt into a form suitable for magnetic separation or flotation (see Patent Document 2). However, the purpose of the technology described in Patent Document 1 is to reuse the recovered electrode material directly as a metal compound for the use of a positive electrode material. Therefore, Patent Document 1 does not focus on recovering nickel or cobalt as metals. Also, the purpose of the technology described in Patent Document 2 is to separate cobalt from a mixture of aluminum, lithium aluminate, copper, copper oxide, and carbon, etc., with a battery using a cobalt-based positive electrode material such as lithium cobaltate as the target; and Patent Document 2 does not mention separating manganese from a ternary positive electrode material (LiNi x Co y Mn z O 2 (x + y + z = 1)) etc., cobalt, nickel, and manganese-containing oxides. Regarding the technology for concentrating cobalt and nickel from a lithium-ion secondary battery, for example, a technology has been proposed in which the 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 (for example, refer to Patent Document 3). In this conventional technology, copper can be separated by leaching cobalt and aluminum into an inorganic acid. In addition, cobalt and aluminum can be separated by adjusting the pH value of the inorganic acid. Also, for example, a technology has been proposed in which a two-stage solvent extraction step is performed on an aqueous solution of a metal mixture of metal group A and metal group B to separate metal group B and manganese from lithium, nickel, and cobalt; wherein, the aforementioned metal group A contains lithium, manganese, nickel, and cobalt, and the aforementioned metal group B contains copper, aluminum, and iron (for example, refer to Patent Document 4). Also, for example, a technology has been proposed in which a waste lithium-ion secondary battery is thermally decomposed, pulverized, and classified under superheated steam at 350°C to 550°C to concentrate the valuable metals contained in the positive electrode material (for example, refer to Patent Document 5). Thereby, it is possible to thermally decompose the organic matter contained in the lithium-ion secondary battery at low cost while suppressing the oxidation of metals and the generation of dioxins, and without melting the aluminum (melting point 660°C) contained in the outer shell and the positive electrode current collector, and it is possible to concentrate the valuable metals contained in the positive electrode material. However, in the technology described in the above-mentioned Patent Document 3, for example, there are problems such as complicated steps of filtering inorganic acids and adjusting the pH value. Also, in the technology described in Patent Document 4, solvent extraction is used to separate manganese from cobalt, nickel, and lithium, so there is a problem that the cost of the extractant and the cost of introducing equipment become too high. Also, in the technology described in Patent Document 5, for example, although aluminum and copper can be decomposed at a high concentration rate, cobalt and nickel cannot be metallized; and metals such as lithium, cobalt, nickel, and manganese can only be concentrated into a mixed compound. [Prior Art Documents] [Patent Documents] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-348782 [Patent Document 2] Japanese Patent Application Laid-Open No. 2017-37807 [Patent Document 3] Japanese Patent Application Laid-Open No. 2019-169309 [Patent Document 4] Japanese Patent No. 5706457 [Patent Document 5] International Publication No. 2012 / 169073 Pamphlet [Problems to be Solved by the Invention] The present invention aims to provide a method for concentrating valuable metals contained in a lithium-ion secondary battery, which targets used lithium-ion secondary batteries, the positive electrode materials of used lithium-ion secondary batteries, or scraps in the manufacturing processes thereof, etc., and can easily obtain metal components enriched with cobalt and nickel; and can easily separate cobalt and nickel and even manganese from other battery components, particularly from composite oxides containing cobalt, nickel, and manganese as positive electrode active materials. [Means for Solving the Problems] To solve the above problems, the inventors of the present invention found the following knowledge after in-depth study: Although cobalt and nickel, which are positive electrode active materials contained in a lithium-ion secondary battery, exist in the form of oxides containing cobalt, nickel, manganese, and lithium, by performing heat treatment under specific conditions based on thermodynamic theory calculations, the cobalt and nickel in the oxides can be transformed into metals, and manganese, etc. can be kept in the form of oxides, and thus metal components of cobalt and nickel with increased concentration (enrichment) can be effectively obtained. The present invention was completed by the inventors based on the aforementioned knowledge, and as a means for solving the aforementioned problems, it is as described below. That is, <1> A method for concentrating valuable metals contained in a lithium-ion secondary battery, characterized by comprising: the method for concentrating valuable metals contained in the aforementioned lithium-ion secondary battery is to process a lithium-ion secondary battery or its positive electrode material containing at least one element of cobalt and nickel to concentrate at least one valuable metal containing cobalt and nickel; and a heat treatment step, which is to perform heat treatment on the aforementioned lithium-ion secondary battery or its positive electrode material and form a lump containing at least one valuable metal of cobalt and nickel. <2> The method for concentrating valuable metals contained in a lithium-ion secondary battery as described in <1>, wherein, in the aforementioned heat treatment step, the heat treatment is performed on the aforementioned lithium-ion secondary battery or its positive electrode material in a reducing atmosphere or an inert gas atmosphere. <3> The method for concentrating valuable metals contained in a lithium-ion secondary battery as described in <1> or <2>, wherein, in the aforementioned heat treatment step, the heat treatment is performed in a state where the lithium-ion secondary battery is housed in a casing, and the aforementioned casing has a melting point above the heat treatment temperature. <4> The method for concentrating valuable metals contained in a lithium-ion secondary battery as described in <3>, wherein the aforementioned casing is an outer packaging casing of a battery pack, a battery module, or a battery cell in the lithium-ion secondary battery. <5> The method for concentrating valuable metals contained in a lithium-ion secondary battery as described in any one of <1> to <4>, wherein, in the aforementioned heat treatment step, the heat treatment is performed in the following state: there is a state of 10% by mass or more of carbon relative to the total mass% of at least one of cobalt and nickel contained in the aforementioned lithium-ion secondary battery or its positive electrode material. <6> The method for concentrating valuable metals contained in a lithium-ion secondary battery as described in <5>, wherein the aforementioned carbon contains carbon from the negative electrode material of the lithium-ion secondary battery. <7> The method for concentrating valuable metals contained in a lithium-ion secondary battery as described in any one of <1> to <6>, further comprising: a pulverizing step, which is to pulverize the heat treatment product of the aforementioned lithium-ion secondary battery or its positive electrode material obtained in the aforementioned heat treatment step; a sorting step, which is to sort and recover a product concentrated with at least one of cobalt and nickel from the pulverized product of the aforementioned heat treatment product obtained in the aforementioned pulverizing step. <8> The method for concentrating valuable metals contained in a lithium-ion secondary battery as described in <7>, wherein the aforementioned sorting step includes: a first sorting step, which is to use a sieve with a mesh size of 0.1 mm to 2.4 mm to classify the aforementioned pulverized product obtained in the aforementioned pulverizing step and classify it into a coarse-grained product and a fine-grained product; a second sorting step, which is to separate the fine-grained product obtained in the aforementioned first sorting step by using at least one difference among magnetism, particle size, and specific gravity.<9>The method for concentrating valuable metals contained in the lithium-ion secondary battery as described in <8>, further comprising: a fine pulverization step of further finely pulverizing the fine grain product obtained in the first sorting step; and performing the second sorting step on the finely pulverized product obtained in the fine pulverization step. <10>The method for concentrating valuable metals contained in the lithium-ion secondary battery as described in <9>, wherein the cumulative 50% volume particle diameter D of the finely pulverized product. 50is 75 μm or less. <11> A method for concentrating valuable metals contained in a lithium-ion secondary battery as described in any one of <7> to <10>, wherein the sorting step is a magnetic sorting step, and the magnetic flux density of the magnet in the magnetic sorting step is 0.01 tesla or more and 2 tesla or less. <12> A method for concentrating valuable metals contained in a lithium-ion secondary battery as described in <11>, wherein the magnetic sorting step is a wet magnetic sorting. <13> A method for concentrating valuable metals contained in a lithium-ion secondary battery as described in <12>, wherein a dispersant of 50 mg / L or more is added to the slurry applicable to the wet magnetic sorting. <14> A method for concentrating valuable metals contained in a lithium-ion secondary battery as described in <12> or <13>, wherein ultrasonic particle dispersion treatment is performed on the slurry applicable to the wet magnetic sorting. <15> A method for concentrating valuable metals contained in a lithium-ion secondary battery as described in any one of <1> to <14>, wherein in the heat treatment step, heat treatment is performed at 750 °C or more and 1200 °C or less for 1 hour or more. <16> A method for concentrating valuable metals contained in a lithium-ion secondary battery, characterized by comprising: the method for concentrating valuable metals contained in the lithium-ion secondary battery is to treat a lithium-ion secondary battery or its positive electrode material containing at least one element of cobalt and nickel to concentrate at least one valuable metal containing cobalt and nickel; and a heat treatment step of heating the lithium-ion secondary battery or its positive electrode material to 600 °C to 1200 °C; a pulverization and classification step of pulverizing and classifying the heat-treated product obtained in the heat treatment step; a re-heat treatment step of re-heating the fine particle product obtained in the pulverization and classification step to 300 °C to 1200 °C and forming an agglomerate containing at least one of cobalt and nickel. <17> A method for concentrating valuable metals contained in a lithium-ion secondary battery as described in <16>, wherein the negative electrode material of the lithium-ion secondary battery includes carbon. <18> A method for concentrating valuable metals contained in a lithium-ion secondary battery as described in <16> or <17>, further comprising: a sorting step of sorting and recovering a product concentrated with at least one of cobalt and nickel from the re-heat treated product obtained in the re-heat treatment step. <19> A method for concentrating valuable metals contained in a lithium-ion secondary battery as described in <18>, wherein the sorting step is to recover a product concentrated with at least one of cobalt and nickel and a product concentrated with manganese. <20> A method for concentrating valuable metals contained in a lithium-ion secondary battery as described in <18> or <19>, wherein the sorting step is a step of separating using at least one difference among magnetism, particle size, and specific gravity.<21> The method for concentrating valuable metals contained in a lithium-ion secondary battery as described in any one of <16> to <20>, wherein, in the heat treatment step, the lithium-ion secondary battery is housed in an aluminum-containing casing, and aluminum is separated from the casing during heating. <22> The method for concentrating valuable metals contained in a lithium-ion secondary battery as described in any one of <16> to <21>, wherein, in the pulverization classification step, pulverization by impact, shearing or compression is performed, and classification is carried out using a sieve with a mesh size of 0.1 mm to 2.4 mm. <23> The method for concentrating valuable metals contained in a lithium-ion secondary battery as described in any one of <16> to <22>, wherein, in the re-heat treatment step, the cumulative 50% volume particle diameter D of the granule containing at least one metal of cobalt and nickel. 50 is 1 μm or more. <24> The method for concentrating valuable metals contained in a lithium-ion secondary battery as described in any one of <18> to <23>, wherein the sorting step is a magnetic sorting step, and the magnetic flux density of the magnet in the magnetic sorting step is 0.01 tesla or more and 2 tesla or less. <25> The method for concentrating valuable metals contained in a lithium-ion secondary battery as described in <24>, wherein the magnetic sorting step is a wet magnetic sorting, and a dispersant of 50 mg / L or more is added to the slurry applicable to the wet magnetic sorting. <26> The method for concentrating valuable metals contained in a lithium-ion secondary battery as described in <25>, wherein ultrasonic particle dispersion treatment is performed on the slurry applicable to the wet magnetic sorting. <27> The method for concentrating valuable metals contained in a lithium-ion secondary battery as described in any one of <16> to <26>, wherein, in at least one of the heat treatment step and the re-heat treatment step, a reducing component is added to form a reducing atmosphere. <28> The method for concentrating valuable metals contained in a lithium-ion secondary battery as described in any one of <16> to <27>, wherein, in the heat treatment step or the re-heat treatment step, a part of the heat treatment time is heated in an air atmosphere or an oxidation atmosphere, and the mass of the reducing component of the heat-treated product or the re-heat-treated product is reduced. <29> The method for concentrating valuable metals contained in a lithium-ion secondary battery as described in any one of <18> to <28>, wherein, after the re-heat treatment step and before the sorting step, a re-pulverization step of re-pulverizing the heat-treated product is performed. <30> The method for concentrating valuable metals contained in a lithium-ion secondary battery as described in any one of <16> to <29>, wherein, for the fine particle product obtained in the pulverization classification step, a magnetic sorting step using magnetism is performed; and the re-heat treatment step is performed on the magnetic substance obtained in the magnetic sorting step. [Advantages of the Invention] According to the first embodiment of the present invention, since the lithium-ion secondary battery or its positive electrode material is heat-treated to form agglomerates containing at least one valuable metal among cobalt and nickel, a method for concentrating the valuable metals contained in a lithium-ion secondary battery can be provided, which can easily obtain a metal component concentrated with cobalt and nickel, and the aforementioned metal component can be easily separated from other battery components. Also, according to the second embodiment of the present invention, since pulverization classification is performed after heat treatment at a specific temperature and then re-heat treatment is performed, a method for concentrating the valuable metals contained in a lithium-ion secondary battery can be provided, which can easily obtain a metal component concentrated with cobalt and nickel, and the aforementioned metal component can be easily separated from other battery components. In other words, according to the present invention, a method for concentrating the valuable metals contained in a lithium-ion secondary battery can be provided, which uses a used lithium-ion secondary battery or the positive electrode material of a used lithium-ion secondary battery or waste (scrap) in the manufacturing process thereof as an object, and can easily obtain a metal component concentrated with cobalt and nickel; and cobalt and nickel and even manganese can be easily separated from other battery components, particularly from a composite oxide containing cobalt, nickel, and manganese as a positive electrode active material. In the method for concentrating the valuable metals contained in the lithium-ion secondary battery according to the first embodiment of the present invention, through the heat treatment step, the lithium-ion secondary battery or its positive electrode material containing at least one element among cobalt and nickel is heat-treated to form agglomerates containing at least one valuable metal among cobalt and nickel, and at least one of cobalt and nickel can be metallized to form agglomerates of valuable metals with increased (concentrated) concentrations of cobalt and nickel. In this way, in the first embodiment of the present invention, a valuable substance concentrated with at least one of cobalt and nickel can be obtained from the lithium-ion secondary battery or its positive electrode material containing at least one of cobalt and nickel as a constituent component. At least one of cobalt and nickel is metallized by heat treatment, and then, through the pulverization step and the sorting step, cobalt and nickel can be sorted out from other battery components, and a valuable substance with a higher (concentrated) concentration of cobalt and nickel can be obtained. Also, in the first embodiment of the present invention, it is preferably heat-treated in a reducing atmosphere or an inert gas atmosphere. In the first embodiment of the present invention, by heat-treating in a reducing atmosphere or an inert gas atmosphere, it becomes easier to form agglomerates of valuable metals containing at least one of cobalt and nickel. Here, metallization means changing cobalt or nickel existing in a compound as follows into a metal: a compound containing oxides of cobalt and nickel, lithium cobaltate (LiCoO 2 ), lithium cobalt nickelate (LiCo 1 / 2 Ni 1 / 2 O 2 ) The LiNi, known as ternary systems and NCM systems, etc. x Co y Mn z O 2 (x + y + z = 1), the LiNi, known as NCA systems, etc. x Co y Al z (x + y + z = 1). Metallization means that all are metallized into particles, or a part is metallized, so it is not necessary to be a pure substance in particular. In this way, the metallization of cobalt or nickel means to become a state with a specific gravity and magnetism close to those of cobalt or nickel metals. Also, the metallized cobalt or nickel can also be in the alloy state of cobalt and nickel. In the method for concentrating valuable metals contained in the lithium ion secondary battery according to the second embodiment of the present invention, by performing a heat treatment step, a pulverization classification step, and a reheat treatment step on a lithium ion secondary battery or a positive electrode material thereof containing at least one element of cobalt and nickel, at least one of cobalt and nickel can be metallized to form an agglomerate of valuable metals with increased (concentrated) concentrations of cobalt and nickel. In the aforementioned heat treatment step, the positive electrode material present in the form of an oxide containing cobalt, nickel, manganese, and lithium is heat-treated in a state of being a component of a cell, a battery module, or a battery pack included in the lithium ion secondary battery. By performing this heat treatment, it is possible to suppress the combustion consumption of carbon in the lithium ion secondary battery and effectively form metals of cobalt and nickel. The metals of cobalt and nickel form agglomerated particles with, for example, oxide particles of manganese. If the heat-treated product obtained in the aforementioned heat treatment step is subjected to a pulverization classification treatment, the fine particle product mainly contains cobalt, nickel, manganese, and carbon. By performing a reheat treatment on these powders, it is possible to use the fine cobalt and nickel metals generated in the aforementioned heat treatment step as nuclei and grow cobalt and nickel into larger agglomerates (by reducing the fine metals of cobalt and nickel and the cobalt and nickel oxides forming aggregates, the particle size of the aforementioned fine metals is increased), or increase the particle size of each agglomerate through melting / binding. As a result, a clear solid-solid interface is formed between the aforementioned agglomerates and oxides such as manganese forming the original aggregates. Thereby, sorting and concentration become easier. In this way, in the second embodiment, metals of cobalt and nickel are formed in the aforementioned heat treatment step, and these metals are separated into cobalt, nickel, and manganese in the pulverization classification step, and the agglomerates of metallized cobalt and nickel are grown in the reheat treatment step to form larger agglomerates. Therefore, in the second embodiment, since it is possible to obtain cobalt and nickel as larger metallized agglomerates, it is possible to more easily recover metallized cobalt and nickel. Since this reheat treatment step is performed on the powder, it is possible to improve the contact efficiency between the fine metals of cobalt and nickel and the oxides and carbon and form the aforementioned agglomerates. This reheat treatment not only forms the aforementioned agglomerates but also causes combustion of carbon and can reduce the carbon mass of the product after the reheat treatment. If the heat treatment in the previous step is performed at a temperature lower than 600°C, since it is difficult to form fine metals of cobalt and nickel in this heat treatment, during the reheat treatment, the heat treatment is performed without nuclei for growing the agglomerates of cobalt and nickel; also, before the agglomerates of cobalt and nickel are formed, the carbon is burned and consumed, so it is impossible to form agglomerates of cobalt and nickel with a sufficient size. Moreover, cobalt, nickel, manganese, etc. still remain in the state of forming oxides, and cobalt and nickel exist in a state where it is difficult to be separated from manganese by physical sorting and cannot exhibit sufficient magnetism. In the second embodiment of the present invention, by making the combustion time of at least a part of at least one of the heat treatment step and the reheating treatment step heat at least one of cobalt and nickel in an air atmosphere or an oxidation atmosphere, the mass of the reducing components of the heat-treated product can be reduced. In other words, by consuming the reducing components contained in the heat-treated product, it is possible to prevent the reducing components from being mixed into the fine-grained product described below. (First Embodiment) Hereinafter, first, regarding the first embodiment of the present invention described above, a form of concentrating valuable metals contained in a lithium ion secondary battery by performing a heat treatment step will be described. <Heat Treatment Step> The heat treatment step is a step of heat-treating a lithium ion battery (LIB) or its positive electrode material in a reducing atmosphere or an inert gas atmosphere and forming a lump containing at least one valuable metal of cobalt and nickel. Regarding the heat treatment temperature in the heat treatment step, for example, it is preferably 600°C or higher and 1,200°C or lower, more preferably 700°C or higher and 1,200°C or lower, and still more preferably 750°C or higher and 1,100°C or lower. By making the heat treatment temperature 600°C or higher, the metallization of cobalt and nickel can be efficiently promoted; and by making the heat treatment temperature 1,200°C or lower, the energy and cost required for heat treatment can be suppressed. Regarding the heat treatment time, there is no particular limitation, and it can be appropriately selected according to the purpose. It is preferably 30 minutes or longer and 5 hours or shorter, and more preferably 1 hour or longer and 3 hours or shorter. Regarding the heat treatment time, it is only necessary that the heat treatment time is sufficient to reach the temperature desired for the metallization of cobalt and nickel, and the holding time is only necessary to ensure the time for metallization to proceed. If the heat treatment time is within the preferred range, it is advantageous from the viewpoint of the cost of heat treatment. Therefore, the heat treatment is preferably performed at 750°C or higher and 1,200°C or lower for 1 hour or longer. Regarding the heat treatment method, there is no particular limitation, and it can be appropriately selected according to the purpose. Examples include a method of performing heat treatment using a heat treatment furnace. Examples of the heat treatment furnace include batch furnaces such as muffle furnaces, tunnel furnaces, rotary kilns, fluidized bed furnaces, cupolas, and stoker furnaces. The heat treatment can be carried out in an air atmosphere or an oxidizing atmosphere, or in a reducing atmosphere or an inert gas atmosphere. In terms of the reducing atmosphere, for example, an atmosphere with a low oxygen concentration in the presence of hydrogen or carbon monoxide can be cited. Specifically, it is possible to adjust to an atmosphere with an oxygen concentration of 15% or less. In terms of the inert gas atmosphere, an atmosphere composed of nitrogen or argon, etc. can be cited. In order to easily obtain the pellets after metallizing and concentrating cobalt and nickel, a reducing component can be further added. Thus, in the present invention, when the heat treatment is carried out in an inert gas atmosphere, it is preferably carried out under the condition of the presence of a reducing agent. Thereby, the metallization of cobalt and nickel can be carried out efficiently. As the reducing agent, for example, carbon, hydrogen, carbon monoxide, hydrocarbon gas, and hydrocarbon compounds, etc. can be cited. Also, as the carbon as the reducing agent, for example, the carbon used for the negative electrode material of a lithium ion secondary battery can be cited. The addition amount of the reducing component is preferably 0.1% or more in terms of mass ratio with respect to the content of at least one of cobalt and nickel. In other words, in the heat treatment step of the present invention, it is preferably carried out under the following state: there is a state where there is 10% by mass or more of carbon 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. Here, if the heat treatment is carried out only in air for the following compounds, etc., it is difficult to carry out the metallization reaction of cobalt and nickel: compounds containing oxides of cobalt and nickel, lithium cobaltate (LiCoO 2 ), lithium nickel cobaltate (LiCo 1 / 2 Ni 1 / 2 O 2 ), LiNi called ternary system and NCM system, etc. x Co y Mn z O 2 (x + y + z = 1), LiNi called NCA system, etc. x Co y Al z(x + y + z = 1). However, even if the oxygen concentration is somewhat high, metallization becomes easier to perform at high temperatures, and the particles of metallization tend to become larger. In this case, as described above, the heat treatment temperature is preferably 750°C to 1200°C. Also, even if the oxygen concentration is somewhat high, for example, if there is a sufficient reducing agent (if a reducing atmosphere can be generated), then metallization also becomes easier to perform. Regarding the method of achieving an atmosphere of low oxygen concentration (low oxygen atmosphere), for example, storing a lithium ion secondary battery or its positive electrode material in an oxygen-shielding container and performing heat treatment can be cited. Regarding the material of the oxygen-shielding container, as long as it has durability against the combustion temperature and internal pressure, it is not particularly limited and can be appropriately selected according to the purpose, and examples include iron and stainless steel having a high melting point. Since the lithium ion secondary battery releases gas by the combustion of the internal electrolyte and increases the air pressure, it is preferable to provide an opening in the oxygen-shielding container. In this case, the ratio of the opening area of the aforementioned opening to the surface area of the aforementioned container before the aforementioned opening is provided, that is, the opening ratio is preferably 12.5% or less, more preferably 6.3% or less. By making the opening ratio 12.5% or less, oxidation of cobalt and nickel due to roasting can be suppressed, and cobalt and nickel can be metallized more efficiently. Also, by performing heat treatment on the outer packaging shell of a battery pack, battery module, or battery cell of a lithium ion secondary battery, oxygen can be shielded, and the metallization of cobalt or nickel can be further promoted. In other words, in the present invention, as the oxygen-shielding container, for example, the outer packaging shell of a battery pack, battery module, or battery cell of a lithium ion secondary battery can be cited. In this way, in the heat treatment step of the present invention, it is preferably performed in a state where the lithium ion secondary battery is housed in the shell, and the aforementioned shell has a melting point above the heat treatment temperature; also, regarding the shell, it is preferably possible to use the outer packaging shell of a battery pack, battery module, or battery cell of a lithium ion secondary battery. Also, the cumulative 50% volume particle diameter D of cobalt and nickel after metallization 50 is preferably 1 μm or more, more preferably 1 μm or more and 5,000 μm or less. If the cumulative 50% volume particle diameter D 50 is 1 μm or more, it has the advantage of being easily separated and concentrated in the subsequent sorting step. The cumulative 50% volume particle diameter D 50 can be measured by a particle size distribution meter or the like. Next, after the above heat treatment, although a heat-treated product (LIB heat-treated product) in which metallized cobalt and nickel are mixed with other components can be obtained, in order to separate cobalt and nickel, which are valuable substances to be concentrated, it is preferable to perform a pulverization step and a sorting step. Thereby, it is possible to be in a state where cobalt and nickel can be easily sorted from other battery constituent components (manganese, aluminum, lithium, copper, iron, carbon, etc.). <Pulverization Step> After performing the above heat treatment step, it is preferable to perform a pulverization step, which pulverizes the heat-treated product obtained by the heat treatment. In other words, in the present invention, it is preferable to include a pulverization step, which pulverizes the heat-treated product of the lithium ion secondary battery or its positive electrode material obtained by the heat treatment step. Regarding the pulverization method in the pulverization step, there is no particular limitation, and it can be appropriately selected according to the purpose. Regarding the method of performing pulverization by impact, examples include: a method of throwing and hitting a collision plate with a rotating striking plate to impart impact, and a method of hitting the heat-treated product with a rotating hitting element (Hitter); and for example, a hammer mill and a chain mill can be used. In addition, a method of hitting the heat-treated product with balls or rods made of ceramics or iron, etc. can be cited, and it can be performed by a ball mill or a rod mill. Furthermore, regarding the pulverization method by compression, a twin-screw pulverizer having a short blade width and a short blade length can be used for pulverization. By impact and compression, the pulverization of the active material and the current collector is promoted. On the other hand, the form of copper in the current collector is not likely to change significantly and exists in the form of a foil, etc. By this pulverization, the positive electrode active material containing cobalt and nickel is separated from the current collectors of iron, stainless steel, aluminum, and copper as the outer shell. In the sorting step, a pulverized product can be obtained, which is in a state where these positive electrode active materials and the current collectors of iron, stainless steel, aluminum, and copper can be effectively sorted. Also, by this pulverization step, it is possible to be in a state of separating cobalt and nickel concentrates from the heat-treated product (LIB heat-treated product) in which the metallized cobalt and nickel are mixed with other components, and the size of these concentrates is preferably 2.4 mm or less. Regarding the pulverization time of the pulverization step, there is no particular limitation, and it can be appropriately selected according to the purpose. The pulverization time per 1 kg of the lithium ion secondary battery is preferably 0.1 second or more and 30 minutes or less, more preferably 0.2 second or more and 10 minutes or less, and particularly preferably 0.3 second or more and 5 minutes or less. By making the pulverization time 0.1 second or more and 30 minutes or less, it is possible to pulverize into an appropriate size by classification. <Sorting Step> After performing the above-mentioned crushing step, it is preferably to perform a sorting step, which sorts cobalt and nickel and other constituent components of the positive electrode active material containing manganese oxide or aluminum oxide from the crushed material obtained in the previous crushing step. In other words, in the present invention, it is preferably to have a sorting step, which sorts and recovers a product concentrated with at least one of cobalt and nickel from the crushed material of the heat-treated product obtained in the previous crushing step. Also, regarding the sorting step, as long as it can sort and recover a product concentrated with at least one of cobalt and nickel from the crushed material, there is no particular limitation, and it can be appropriately selected according to the purpose, and preferably includes a first sorting step and a second sorting step as shown below. <<First Sorting Step>> The first sorting step is a step of classifying the crushed material obtained in the crushing step into a coarse-grained product and a fine-grained product. Regarding the classification method, there is no particular limitation, and it can be appropriately selected according to the purpose. Examples include a vibrating sieve, a multi-stage vibrating sieve, a cyclone separator, a standard sieve of JIS Z8801, a wet vibrating table, and an air table. Regarding the mesh size (classification point) of the first sorting step, there is no particular limitation, and it can be appropriately selected according to the purpose. Examples include 0.1 mm or more and 2.4 mm or less, and more preferably 0.6 mm or more and 2.4 mm or less. By making the classification point 2.4 mm or less, it is possible to prevent metal from the outer packaging container and the copper current collector from mixing into the fine-grained product, and to improve the separation result of cobalt and nickel from the active material. Also, by making the mesh size 0.1 mm or more, it is possible to improve the recovery rate of cobalt and nickel from the active material in the fine-grained product. Also, when using a sieve as the classification method, crushing promoters such as stainless steel balls and alumina balls are placed on the sieve and sieved to remove small crushed materials attached to the large crushed materials from the large crushed materials, and it is possible to more effectively separate the large crushed materials and the small crushed materials. Also, iron is mainly contained in the coarse-grained product. It is possible to perform a crushing and classification step (crushing and classification), which classifies the crushed material into a coarse-grained product and a fine-grained product while performing crushing. <<Second Sorting Step>> The second sorting step is a step of separating the fine-grained product obtained in the first sorting step by using at least one of the differences in magnetism, particle size, and specific gravity. By performing the second sorting step, it is possible to obtain a valuable metal with a high concentration (concentration) of cobalt and nickel. <<Second Sorting Step Using Magnetic Difference (Magnetic Separation)>> By magnetizing cobalt and nickel with metal monomers, 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. Thereby, the concentrated metalized cobalt and nickel can be concentrated as valuable substances of magnetic substances. As non-magnetic substances, the concentrated products of manganese, aluminum, lithium, copper, and carbon can be concentrated. Also, regarding the second sorting step (magnetic separation) using magnetic difference, it can be the same as the magnetic separation step of the above-described first embodiment. Therefore, regarding the second sorting step using magnetic difference, it is preferably, for example, a wet magnetic separation step. Also, the magnetic flux density of the magnet used in the magnetic separation step is preferably 0.01 tesla or more and 2 tesla or less. By performing magnetic separation using a magnet having a magnetic flux density of 0.01 tesla or more and 2 tesla or less, valuable substances with high (concentrated) concentrations of cobalt and nickel can be obtained. For example, in the case of a ternary cathode active material (LiNi x Co y Mn z O 2 (x + y + z = 1)), by performing magnetic separation on the fine-grained product obtained in the crushing step and the first sorting step, cobalt and nickel can be separated from manganese, and valuable substances with high (concentrated) concentrations of cobalt and nickel can be obtained. Magnetic separation is preferably wet magnetic separation. This is because wet magnetic separation can suppress cross-linking aggregation caused by moisture between particles during dry magnetic separation, improve the separability of particles, and easily obtain higher-purity cobalt and nickel. In the above-described wet magnetic separation, a dispersant can also be added to the applicable slurry. By adding a dispersant, the separation of cobalt and nickel from other battery constituent components can be promoted. The addition amount of the dispersant is preferably 50 mg / L or more. It is preferably to perform ultrasonic particle dispersion treatment on the slurry applicable to wet magnetic separation. By performing this ultrasonic particle dispersion treatment, the separation of cobalt and nickel from other battery constituent components can be promoted. <<Second Sorting Step Using Particle Size and Specific Gravity (Particle Size and Specific Gravity Sorting)>> By further performing particle size classification sorting and specific gravity sorting on the fine particle product obtained in the first sorting step, valuable substances with high (concentrated) concentrations of cobalt and nickel after metalization can be obtained. The second sorting step using particle size and specific gravity (particle size and specific gravity sorting) can be carried out using various devices, and the various devices mentioned above are, for example, the devices using the classification method and specific gravity sorting method or the combined principle of these as exemplified in the above first embodiment. For the devices using the classification method and specific gravity sorting method or the combined principle of these, there is no particular limitation, and they can be appropriately selected according to the purpose. Examples include dry particle classification devices such as vibrating screens, dry cyclone separators, turbo classifiers, cyclone air classifiers, micron classifiers, elbow jet classifiers, inertial force type air classifiers (Cliffis CF), electrostatic separation devices, etc.; wet particle classification devices such as hydrocyclones, Falcon® concentrators, Nelson® concentrators, multi-gravity separators, laboratory mineral separators, Banner Bertles cross belts, Kelsey jigs, Alter jigs, high-precision wet classifiers (i Classifier), vertical cylindrical wet classifiers, etc. Also, as long as valuable substances with high (concentrated) concentrations of cobalt and nickel as the target can be obtained, the above devices can be appropriately combined and used according to the purpose without particular limitation. For example, in the case of a ternary cathode active material (LiNi x Co y Mn z O 2 (x + y + z = 1)), for the fine particle product obtained in the crushing step and the first sorting step, valuable substances with high (concentrated) concentrations of cobalt and nickel can also be obtained by a sorting method using the specific gravity difference between cobalt and nickel particles and manganese oxide particles, or a classification method using the particle size difference between the two. Also, through the above magnetic separation, specific gravity sorting, sorting using particle size, or various sorts of these compositions, not only can cobalt and nickel and manganese oxide be sorted, but also aluminum, lithium, copper, iron, and carbon, which are other battery constituent components, can be separated. <Micro - pulverization step> Also, in the present invention, preferably, before the second sorting step, that is to say, preferably, the fine - grained product obtained in the first sorting step is further subjected to a micro - pulverization step. That is to say, in the present invention, preferably, the fine - grained product obtained in the first sorting step is further subjected to a micro - pulverization step, and the micro - pulverized material obtained in the micro - pulverization step is subjected to the aforementioned second sorting step. Thereby, since it is possible to suppress the agglomeration or mixing of the metallized (Metalize) particles of cobalt and nickel with other battery - forming components into a lump, it is possible to achieve a higher - precision monomer separation of the metals of cobalt and nickel and manganese oxide. Regarding the micro - pulverizer, there is no particular limitation, and it can be appropriately selected according to the purpose. For example, a bead mill, a roller mill, a jet mill, a hammer mill, a needle mill, a rotary mill, a vibration mill, a planetary mill, an attritor, etc. can be used. The cumulative 50% volume particle diameter D of the micro - pulverized material obtained in the micro - pulverization step 50 is preferably 75 μm or less, more preferably 0.1 μm or more and 75 μm or less, and still more preferably 0.5 μm or more and 53 μm or less. By micro - pulverizing the cumulative 50% volume particle diameter D 50 to 75 μm or less, it is possible to promote the monomer separation of the metals of cobalt and nickel and other constituents. By making the cumulative 50% volume particle diameter D of the micro - pulverized material 50 become 0.1 μm or more, it is possible to prevent the cross - linking of moisture between particles and the electrostatic adhesion force from causing the agglomeration of cobalt and nickel with other battery - forming components, resulting in a decrease in the separability of the two. The cumulative 50% volume particle diameter D 50 is preferably measurable by, for example, a particle size distribution meter, etc. <Other steps> Regarding other steps, there is no particular limitation, and they can be appropriately selected according to the purpose, and examples include a valuable - material recovery step, a valuable - material refining step, etc. (Second Embodiment) Hereinafter, as the second embodiment of the present invention described above, a form of concentrating the valuable metals contained in a lithium - ion secondary battery by performing a heat - treatment step, a pulverization and classification step, and a re - heat - treatment step will be described. Also, in the second embodiment, for steps other than the heat - treatment step and the re - heat - treatment step of the first embodiment, since they may be the same as those of the first embodiment, the description thereof is omitted when necessary. <Heat Treatment Step> In the heat treatment step, the lithium-ion secondary battery or its cathode material is heated to 600°C to 1200°C. From the perspective of the thermal decomposition of the electrode material, the heat treatment temperature is preferably heated to 700°C to 1200°C, more preferably 750°C to 1100°C. If the heat treatment temperature is less than 600°C, it is difficult to carry out the metallization reaction of cobalt and nickel, which is the main purpose. Also, it becomes difficult to melt and separate the aluminum from the outer shell, increasing the load on the crushing step. If the heat treatment temperature is greater than 1200°C, from the perspective of energy and economy, it leads to an increase in cost. Also, if it is greater than 1200°C, other problems such as the melting of the copper foil and the difficulty in recovering the copper foil will occur. Regarding the heat treatment time, as long as it can separate the molten aluminum, it can be appropriately selected. It is preferably 30 minutes or more and 5 hours or less, more preferably 1 hour or more and 3 hours or less. Regarding the heat treatment time, it is preferably the heat treatment time such that the reducing components do not remain in the obtained heat-treated product. From the perspective of the cost of heat treatment, it is preferably heated at 750°C to 1100°C for 1 hour or more. Regarding the heat treatment method, there is no particular limitation, and it can be appropriately selected according to the purpose. Examples include the method of using a heat treatment furnace for heat treatment. Regarding the heat treatment furnace, examples include batch furnaces such as muffle furnaces, tunnel furnaces, rotary kilns, fluidized bed furnaces, cupolas, and stoker furnaces. The heat treatment can be carried out in an air atmosphere or an oxidation atmosphere, or in a reduction atmosphere or an inert gas atmosphere. Regarding the reduction atmosphere, examples include an atmosphere with a low oxygen concentration in the presence of hydrogen or carbon monoxide. Specifically, it can be adjusted to an atmosphere with an oxygen concentration of 15% or less. Regarding the inert gas atmosphere, examples include an atmosphere composed of nitrogen or argon. In order to easily obtain the agglomerates after metallization and concentration of cobalt and nickel, a reducing component can be further added. Thus, in the present invention, when the heat treatment is carried out in an inert gas atmosphere, it is preferably carried out under the condition of the presence of a reducing agent. Thereby, the metallization of cobalt and nickel can be carried out efficiently. Regarding the reducing agent, examples include carbon, hydrogen, carbon monoxide, hydrocarbon gases, and hydrocarbon compounds. Also, regarding the carbon as the reducing agent, for example, the carbon from the negative electrode material of the lithium-ion secondary battery can be used. The addition amount of the reducing component is preferably 0.1% or more in terms of mass ratio relative to the content of at least one of cobalt and nickel. In other words, in the heat treatment step of the present invention, it is preferably carried out under the following state: there is a state where there is 10% by mass or more of carbon relative to the total mass% of at least one of cobalt and nickel contained in the lithium-ion secondary battery or its cathode material. Generally speaking, if heat treatment is carried out in air for compounds such as the following, it is difficult to carry out the metallization reaction of cobalt and nickel: compounds containing oxides of cobalt and nickel, lithium cobaltate (LiCoO 2 ), lithium nickel cobaltate (LiCo 1 / 2 Ni 1 / 2 O 2 ), LiNi x Co y Mn z O 2 (x + y + z = 1), which is called ternary system and NCM system, LiNi x Co y Al z (x + y + z = 1). However, even in air, by making the negative electrode material carbon act as a reducing component, the metallization can be made easier. Also, in the heat treatment in the high temperature range of 600 to 1200 °C, the metallization becomes easier, and there are cases where fine grains of metallized material can be obtained. Also, when the outer packaging case of the lithium ion secondary battery is made of aluminum or contains aluminum, from the viewpoint of concentrating cobalt and nickel in the subsequent steps, it is preferable to separate the molten aluminum from the outer packaging case during the heat treatment. <Crushing and classification step> Next, after the heat treatment step, a heat-treated product (LIB heat-treated product) is obtained. In this heat-treated product, valuable metals such as cobalt and nickel and other battery components (manganese, aluminum, lithium, copper, iron, carbon, etc.) are mainly contained. Therefore, in order to separate cobalt and nickel among the valuable metals to be concentrated, a crushing and classification step of crushing and classifying the aforementioned LIB heat-treated product is carried out. First, regarding the crushing method, the same crushing method as in the crushing step in the above first embodiment can be used. Also, when grains containing metallized cobalt and nickel are formed in the heat treatment step, it is preferable to carry out a crushing method that can crush the grains and other battery components. In the present invention, crushing methods such as bead mills, roller mills, jet mills, hammer mills, needle mills, rotary mills, vibration mills, planetary mills, and attritors can be appropriately used. Regarding the pulverization time, the same pulverization time as in the pulverization step of the above-described first embodiment can be used. Next, by performing classification, the fine-grained product and the coarse-grained product can be separated. The aforementioned fine-grained product contains cobalt and nickel that constitute the pulverized material obtained in the aforementioned pulverization, and the aforementioned coarse-grained product contains the outer packaging shell component and other electrode components. Regarding the sorting method, it is preferably to perform sorting with a mesh size (classification point) of, for example, 0.1 mm to 2.4 mm, and more preferably the classification point is 0.6 mm to 2.4 mm. By making the classification point 2.4 mm or less, it is possible to prevent metal from the outer packaging container and the copper current collector from mixing into the fine-grained product, and it is possible to improve the separation result of cobalt and nickel from the active material. Also, by making the mesh size 0.1 mm or more, it is possible to improve the recovery rate of cobalt and nickel from the active material in the fine-grained product. Classification can use, for example, dry particulate classification devices such as vibrating screens, standard screens of JIS Z8801, wet vibrating tables, air tables, dry cyclone separators, turbo classifiers, cyclone air classifiers, micron classifiers, elbow jet classifiers, inertial force type air classifiers (Cliffis CF), electrostatic separation devices, etc.; wet particulate classification devices such as hydrocyclones, Falcon® concentrators, Nelson® concentrators, multi-gravity separators, laboratory mineral separators, Banner Bertles cross belts, Kelsey jigs, Alter jigs, high-precision wet classifiers (i Classifier), vertical cylindrical wet classifiers, etc. Also, when using a sieve as the classification method, pulverization promoters such as stainless steel balls and alumina balls are placed on the sieve and sieved to remove small pulverized materials attached to the large pulverized materials from the large pulverized materials, and it is possible to more effectively separate the large pulverized materials and the small pulverized materials. Also, iron is mainly contained in the coarse-grained product. It is possible to perform the pulverization and classification steps (pulverization and classification), which classify the crushed materials into coarse-grained products and fine-grained products while performing pulverization. Also, it is preferably to perform a magnetic separation step using magnetism on the fine-grained product obtained in the pulverization classification step, and perform a reheating treatment step on the magnetic material obtained in the magnetic separation step. In other words, it is preferably to perform magnetic separation on the fine-grained product and perform a subsequent reheating treatment step on the obtained magnetic material. Thereby, it becomes easy to increase the abundance ratio of cobalt and nickel as magnetic materials, and it becomes easy to form agglomerates in the reheating treatment step. <Re-heat treatment step> Next, in the re-heat treatment step, the fine-grained product obtained in the aforementioned pulverization and 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. Thereby, it is possible to form agglomerates of metallized cobalt and nickel contained in the fine-grained product. The higher the temperature of the re-heat treatment, the easier it is to carry out the reaction for forming the metallized agglomerates. When the temperature is less than 300 °C, the aforementioned agglomerates are not formed, and if it is greater than 1200 °C, manganese will melt and other substances other than the target substance will be mixed into the aforementioned agglomerates. Also, in the re-heat treatment step, for example, through the pulverization and classification step as the previous step, a powder containing cobalt, nickel, and manganese as a fine-grained product is recovered, and carbon (from the negative electrode material) that acts as a reducing agent is also included as necessary to perform a re-heat treatment. 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 becomes easier to carry out. As a result, the metallization reaction and the formation of agglomerates are more likely to occur. In contrast, in the initial heat treatment step, as a configuration of the battery, the negative electrode that acts as a reducing agent and the positive electrode material containing cobalt and nickel that is the reduction target are arranged in layers by a separator; therefore, although various powderings and the metallization of cobalt and nickel are carried out, it is difficult for contact to occur between the various powders, and it is difficult to carry out the reaction for forming agglomerates. Also, in some lithium-ion secondary batteries, carbon is added to the positive electrode material as a conductive aid, although this is helpful for the reduction reaction, but when performing a re-heat treatment, it becomes easier for contact to occur (higher contact probability), and it becomes easier for the metallization reaction and the formation of agglomerates to occur; wherein, the aforementioned re-heat treatment is to recover the powder containing cobalt, nickel, and manganese as a fine-grained product, and carbon (from the negative electrode material) that acts as a reducing agent is also included as necessary. Here, the cumulative 50% volume particle diameter D of the agglomerates containing metallized cobalt and nickel formed in the re-heat treatment step 50 is preferably 1 μm or more, more preferably 5 μm to 1000 μm. If it is such a size, it is possible to efficiently recover the agglomerates concentrated with cobalt and nickel as valuable metals. If the cumulative 50% volume particle diameter D 50 is 1 μm or more, it has the advantage of being easily separated and concentrated 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, the size of the agglomerate precursor contained in the fine-grained product is preferably 0.01 to 1 μm, and the size of the agglomerates obtained by the re-heat treatment is preferably 1 to 100 μm. Regarding the heating time of the foregoing reheating treatment step, it can be appropriately selected as long as it can significantly grow the cobalt and nickel agglomerates. Preferably, it is 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 the heating time that does not leave the reducing components in the obtained heat-treated product. Also, regarding the atmosphere used in the foregoing reheating treatment, similar to the above heat treatment step, from the viewpoints of the metallization of cobalt and nickel and the formation of agglomerates, it is preferably carried out in a reducing atmosphere or an inert gas atmosphere. Also, in the reheating treatment, a part of the time is preferably heated in an air atmosphere or an oxidizing atmosphere. Thereby, since the reducing components contained in the heat-treated product can be consumed, the mixing into the fine particle product can be avoided. Also, preferably, a sorting step is carried out after the foregoing reheating treatment step. Thereby, the agglomerates concentrated with cobalt and nickel or any one of them can be sorted and recovered from the reheated product. On the other hand, products concentrated with manganese can be recovered outside these agglomerates. Representatively, cobalt and nickel can be magnetized with a metal monomer, and a wet or dry magnetic separation step (dry magnetic separation or wet magnetic separation) can be carried out. Thereby, the agglomerates containing metallized cobalt and nickel formed from the fine particle product in the reheating treatment step can be recovered as magnetic substances. As non-magnetic substances, manganese, aluminum, lithium, copper, and carbon can be recovered. Also, the magnetic flux density of the magnet used in the magnetic separation step is preferably 0.01 tesla or more and 2 tesla or less. By performing magnetic separation using a magnet having a magnetic flux density in the above range, the agglomerates of valuable metals with high (concentrated) concentrations of cobalt and nickel can be separated. For example, in a ternary cathode active material (LiNi x Co y Mn z O 2In the case of (x + y + z = 1), by subjecting the heat-treated product obtained by reheating the fine-grained product obtained in the sieving in the crushing and classification step to magnetic separation, it is possible to recover the agglomerates with high (concentrated) concentrations of cobalt and nickel as magnetic substances. The magnetic separation is preferably wet magnetic separation. This is because wet magnetic separation can suppress the cross-linking aggregation caused by the moisture between particles generated during dry magnetic separation, improve the separability of particles, and can easily obtain higher-purity cobalt and nickel. In the aforementioned wet magnetic separation, a dispersant can also be added to the applicable slurry. By adding the dispersant, the separation of cobalt and nickel from other battery components can be promoted. The addition amount of the dispersant is preferably 50 mg / L or more. Also, it is preferable to perform ultrasonic particle dispersion treatment on the slurry applicable to the aforementioned wet magnetic separation. By performing this ultrasonic particle dispersion treatment, the separation of cobalt and nickel from other battery components can be promoted. As an alternative to the aforementioned magnetic separation, it is possible to obtain valuable substances with high (concentrated) concentrations of metalized cobalt and nickel by further performing particle size classification and specific gravity separation. Regarding the device that utilizes the classification method and the specific gravity separation method or the combination principle of these, there is no particular limitation, and it can be appropriately selected according to the purpose. Examples include dry particle classification devices such as vibrating sieves, dry cyclone separators, turbo classifiers, cyclone air classifiers, micron classifiers, elbow jet classifiers, inertial force type air classifiers (Cliffis CF), electrostatic separation devices, etc.; wet particle classification devices such as hydrocyclones, Falcon® concentrators, Nelson® concentrators, multi-gravity separators, laboratory mineral separators, Banner Bertles cross belts, Kelsey jigs, Alter jigs, high-precision wet classifiers (i Classifier), vertical cylindrical wet classifiers, etc. Also, as long as valuable substances with high (concentrated) concentrations of cobalt and nickel as the target can be obtained, the above devices can be appropriately combined and used according to the purpose without particular limitation. Before the above-mentioned classification step, it is also possible to re-crush the heat-treated product of the fine-grained product after the reheating treatment. Thereby, it is possible to suppress the aggregation or mixing of the cobalt and nickel-containing metalized lumps with other battery components into a lump. Also, since cobalt and nickel are metals, it is difficult to make them into fine grains by re-crushing, and since oxides such as manganese are easily made into fine grains by re-crushing, impurities other than cobalt or nickel can be selectively crushed. Therefore, by performing physical separation such as classification, specific gravity separation, and magnetic separation on the re-crushed product, cobalt and nickel can be concentrated into a coarse-grained product, a heavy product, and a magnetic product, and oxides such as manganese that become fine grains can be separated into a fine-grained product, a light product, and a non-magnetic product. Next, for example, in the case of magnetic separation, the separation of cobalt and nickel metals from manganese oxides becomes more accurate. The above-mentioned re-crushing only needs to be crushing that maintains the lumps of metalized cobalt and nickel while releasing the mixed state of the lumps and other battery components, and a crusher can be appropriately selected according to the purpose. As for the crusher, for example, a bead mill, a roller mill, a jet mill, a hammer mill, a needle mill, a rotary mill, a vibration mill, a planetary mill, a grinder, etc. can be used. <Other steps> For other steps, there is no particular limitation, and it can be appropriately selected according to the purpose. Examples include a valuable metal recovery step, a valuable metal refining step, etc. In the method for concentrating valuable metals contained in the lithium-ion secondary battery of the present invention described above, an example of the target raw material is as follows. <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. Examples include a battery cell, a battery module connected with a plurality of battery cells, and a battery pack that houses the battery module in a container, etc. Among them, the aforementioned battery cell includes: a positive electrode, a negative electrode, a separator, an electrolyte containing an electrolyte and an organic solvent, and an outer packaging container that is a battery case for housing the positive electrode, the negative electrode, the separator, and the electrolyte. There is no particular limitation on the shape, structure, size, material, etc. of the lithium-ion secondary battery, and it can be appropriately selected according to the purpose. As for the shape of the lithium-ion secondary battery, examples include a laminated type, a cylindrical type, a button type, a coin type, an angular type, a flat type, etc. <Positive electrode, positive electrode current collector, and positive electrode active material> As for the positive electrode, as long as it has a positive electrode material on the positive electrode current collector, there is no particular limitation, and it can be appropriately selected according to the purpose. As for the shape of the positive electrode, there is no particular limitation, and it can be appropriately selected according to the purpose. Examples include a flat plate shape, a sheet shape, etc. Regarding the positive electrode current collector, its shape, structure, dimensions, material, etc. are not particularly limited and can be appropriately selected according to the purpose. Regarding the shape of the positive electrode current collector, for example, a foil shape can be cited. Regarding the material of the positive electrode current collector, for example, stainless steel, nickel, aluminum, copper, titanium, tantalum, etc. can be cited. Regarding the positive electrode material, it is not particularly limited and can be appropriately selected according to the purpose. For example, a positive electrode material containing at least a rare valuable metal in the positive electrode active material and, if necessary, also containing a conductive agent and a binder resin can be cited. Regarding the rare valuable metal, it is not particularly limited and can be appropriately selected according to the purpose, and preferably contains at least one of cobalt and nickel. Regarding the positive electrode active material, for example: lithium cobaltate (LiCoO 2 ), lithium nickel cobaltate (LiCo 1 / 2 Ni 1 / 2 O 2 ), LiNi called ternary and NCM systems, etc. x Co y Mn z O 2 (x + y + z = 1), LiNi called NCA system, etc. x Co y Al z (x + y + z = 1) or a composite of these, etc. <Negative electrode, negative electrode current collector and negative electrode active material> Regarding the negative electrode, as long as it has a negative electrode material on the negative electrode current collector, it is not particularly limited and can be appropriately selected according to the purpose. Regarding the shape of the negative electrode, it is not particularly limited and can be appropriately selected according to the purpose. For example, a flat plate shape, a sheet shape, etc. can be cited. Regarding the negative electrode current collector, its shape, structure, dimensions, material, etc. are not particularly limited and can be appropriately selected according to the purpose. Regarding the shape of the negative electrode current collector, for example, a foil shape can be cited. Regarding the material of the negative electrode current collector, for example, stainless steel, nickel, aluminum, copper, titanium, tantalum, etc. can be cited. Among these, copper is preferred. Regarding the negative electrode material, it is not particularly limited and can be appropriately selected according to the purpose. For example, a negative electrode material containing at least a negative electrode active material and, if necessary, also containing a conductive agent and a binder resin can be cited. Regarding the negative electrode active material, there is no particular limitation, and it can be appropriately selected according to the purpose. Examples include carbon materials such as carbon black, graphite, carbon fiber, metal carbide, organic matter, and carbide of organic matter; titanate, silicon, or a composite of these. The carbon material as the negative electrode active material can act as a reducing agent during heat treatment and promote the metallization of cobalt and nickel. <Outer packaging container> Regarding the material of the outer packaging container (outer shell) of the lithium ion secondary battery, there is no particular limitation, and it can be appropriately selected according to the purpose. Examples include aluminum, resin (plastic), stainless steel, iron, or other alloys. [Examples] The examples of the present invention will be described below, but the present invention is not limited to these examples. (Example 1) As the raw material (target sample) to be processed, 295 kg of a used in-vehicle lithium ion secondary battery pack was prepared. The positive electrode material contained in the battery is a ternary positive electrode active material, and its composition is (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. As the oxygen shielding container, the iron outer packaging case of the aforementioned battery pack is used. While the aforementioned battery pack remains intact, a burner type fixed bed furnace (industrial furnace) is used for heat treatment at 750 °C for 1 hour. The heat treated product is crushed using a hammer mill (manufactured by Makino Co., Ltd., HC-20), and then classified using a 1.2 mm vibrating sieve to recover 60 kg of fine grain product under the sieve. Also, when analyzing the composition of the fine grain product, the composition of the fine grain product is: 12 mass% cobalt, 12 mass% nickel, and 11 mass% manganese. Photographs of the scanning electron microscope (SEM) of the fine grain product are shown in FIGS. 1 and 2. In FIG. 1, in the area surrounded by the circle, the bright (white) dot-like parts appear to be metallized cobalt and nickel. As shown in FIG. 1, at this time, fine grains after cobalt and nickel are metallized can be confirmed on the surface of the positive electrode material particles. Also, at this time, the particle diameters of the metallized cobalt and nickel are very small, and most of them are particles with a particle diameter of less than 1 μm. In addition, FIG. 2 is an SEM photograph of the coarse grain product taken in a different field of view from FIG. 1, where the metallized cobalt and nickel are distributed in the area surrounded by the dashed line, and manganese oxide is distributed in the area surrounded by the solid line. As shown in FIGS. 1 and 2, it is confirmed that the particles of cobalt and nickel in the fine grain product exist as particles separated from the manganese oxide. Also, in Example 1, although the inside of the burner type fixed bed furnace has an oxidizing atmosphere, the iron outer shell of the battery pack is directly used as the oxygen shielding container, and since the carbon used as the negative electrode active material of the lithium ion secondary battery acts as a reducing agent, the atmosphere inside the outer packaging case becomes a reducing atmosphere. Here, in Example 1, heat treatment is carried out in a state where the amount of carbon as the reducing agent is 135 mass% relative 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 taken, and the atmosphere was set to a reducing atmosphere (a state in which carbon from the negative electrode active material was placed in a container as a reducing agent and covered), and heat treatment (re-heat treatment) was performed at 1000 °C for 1 hour to obtain a re-heat treated product. The heat treatment was carried out in the presence of carbon with a carbon content of 135% by mass relative to the total amount of cobalt and nickel contained in the lithium-ion secondary battery. As a result, it was confirmed that the cobalt and nickel contained in the fine-grained product were metalized, and the fine grains became agglomerates. That is, samples were taken from a part of the bright white area (solid line) and the gray area (dashed line) shown in the scanning electron microscope (SEM) photograph of Fig. 3A, respectively, and elemental analysis was performed using EDS (energy dispersive X-ray spectrometer). As a result, from the peaks obtained from spectrum 179 shown in Fig. 3B, it was found that the area surrounded by the solid line contained a large amount of cobalt and nickel. On the other hand, from the peaks obtained from spectrum 180 shown in Fig. 3C, it was found that the area surrounded by the dashed line contained a large amount of manganese and oxygen. In this way, in the area surrounded by the solid line in Fig. 3A, metalized agglomerates mainly composed of cobalt and nickel were formed, and in the area surrounded by the dashed line in Fig. 3A, manganese oxide composed of manganese and oxygen was formed. Also, in the electron microscope image shown in Fig. 3A, it can be seen that the agglomerates had grown into块状物 of about 1 to 10 μm. Also, Fig. 3D shows an SEM photograph of the state observed after 1 hour of heat treatment. It was confirmed that even after 1 hour of heat treatment, agglomerates were formed. Next, a drum-type magnetic separator (manufactured by Nippon Elise Magnetics Co., Ltd., WDL8 laboratory model) was used to perform wet magnetic separation on the re-heat treated product obtained by re-heat treatment to recover magnetic substances and non-magnetic slurries. The conditions for the wet magnetic separation were: magnetic flux density: 1500 G (0.15 Tesla); drum rotation speed: 30 rpm; solid-liquid ratio: 10%; slurry supply speed: 2 L / min (minute). Also, in the wet magnetic separation for the re-heat treated product, a dispersant was added to the slurry of the re-heat treated product so that the amount of the dispersant relative to the amount of carbon was about 6%, and then ultrasonic particle dispersion treatment was performed. As a result, agglomerates containing metalized cobalt and nickel were obtained as magnetic substances. This confirmed that manganese oxides and the like in the non-magnetic substances were in a separated state. Figure 4A shows a scanning electron microscope (SEM) photograph of the fine-grained product before wet magnetic separation. In Figure 4A, it is confirmed that the area surrounded by the solid line is a lump of cobalt and nickel, and the area surrounded by the dashed line is manganese oxide. That is to say, a part of the bright and white area (solid line) and the dark gray area (dashed line) shown in the scanning electron microscope (SEM) photograph of Figure 4A was taken respectively, and elemental analysis was performed using EDS. As a result, from the peaks obtained in Spectrum 171 shown in Figure 4B, it was found that the area surrounded by the solid line is a lump of cobalt and nickel. On the other hand, from the peaks obtained in Spectrum 173 shown in Figure 4C, it was found that the area surrounded by the dashed line is manganese oxide. Also, it can be speculated that the particles darker than the dashed line area in the electron microscope image are carbon. Figure 5A shows a scanning electron microscope (SEM) photograph of the fine-grained product after wet magnetic separation. In Figure 5A, it is confirmed that the area surrounded by the solid line is a lump of cobalt and nickel, and the area surrounded by the dashed line is manganese oxide. That is to say, a part of the bright and white area (solid line) and the dark gray area (dashed line) shown in the scanning electron microscope image of Figure 5A was taken respectively, and elemental analysis was performed using EDS. As a result, from the peaks obtained in Spectrum 136 shown in Figure 5B, it was found that the area surrounded by the solid line is a lump of cobalt and nickel. On the other hand, from the peaks obtained in Spectrum 135 shown in Figure 5C, it was found that the area surrounded by the dashed line is manganese oxide. Also, it can be speculated that the particles darker than the dashed line area in the electron microscope image are carbon. From the above, it can be known that, as shown in Figure 4A, in the fine grains before magnetic separation, lumps of cobalt and nickel were observed with a frequency equal to that of manganese oxide; in contrast, as shown in Figure 5A, after magnetic separation, the proportion of manganese oxide decreased, and the proportion of lumps of cobalt and nickel increased compared to before magnetic separation. In this way, in Example 1 of the present invention, cobalt and nickel can be concentrated from the lithium-ion secondary battery after metalization. (Example 2) In Example 2, in addition to further pulverizing (micropulverizing) the product after heat treatment, and then further performing wet magnetic separation, the same as in Example 1, a concentrate of cobalt and nickel was obtained. More specifically, in Example 2, a vibration mill (manufactured by Lecce Company, RS200) was used to micropulverize the particles that are lumps of metals and oxides in the fine-grained product. The cumulative 50% volume particle size D of the micropulverized product after micropulverization 50 was 3.9 μm. By performing micropulverization, the metals of cobalt and nickel and manganese oxide can be more accurately separated into monomers. The monomer separation at this time means a state in which the metal particles of cobalt and nickel and the oxide particles of manganese exist separately. FIG. 6A is a SEM photograph taken after photographing an example of a product obtained by micro - pulverizing particles of a lump of metal and oxide as fine - grained products. In FIG. 6A, particles a after cobalt and nickel metallization are distributed in the region surrounded by the dashed line, and particles b of manganese oxide are distributed in the region surrounded by the solid line. FIG. 6B is a diagram showing the result obtained by subjecting a part of the particles a metallized with cobalt and nickel in FIG. 6A in an embodiment of the present invention to elemental analysis using EDS. FIG. 6C is a diagram showing the result obtained by subjecting a part of the particles b of manganese oxide in FIG. 6A to elemental analysis using EDS (energy - dispersive X - ray spectroscope). As shown in FIGS. 6B and 6C, it was confirmed that cobalt and nickel were concentrated in the particles a after cobalt and nickel metallization, and manganese oxide was concentrated in the particles b of manganese oxide. Also, in Example 2, in the same manner as in Example 1, wet magnetic separation was performed using a drum - type magnetic separator to recover magnetic substances and non - magnetic slurries. As the magnetic substances, lumps containing metallized cobalt and nickel were recovered; as the non - magnetic substances, manganese oxide and the like were recovered. (Example 3) In Example 3, in the same manner as in Example 1, heat treatment, pulverization, and sieving of a battery pack of a lithium - ion secondary battery were carried out, and a fine - grained product was obtained under the sieve. Next, in Example 3, wet magnetic separation (first time, wet magnetic separation before reheating treatment) was performed on the obtained fine - grained product under the same conditions as in Example 1, and a magnetic substance was obtained. Next, in Example 3, the obtained magnetic substance was subjected to reheating treatment under the same conditions as in Example 1, and the heat - treated product obtained by the reheating treatment was further subjected to wet magnetic separation (second time, corresponding to the wet magnetic separation of Examples 1 and 2) to obtain a magnetic substance. Here, in the second wet magnetic separation, a drum - type magnetic separator was used and under the same conditions as in Example 1, magnetic substances and non - magnetic substances were separated. Also, when the obtained magnetic substance was analyzed, it was found that cobalt and nickel were concentrated in the magnetic substance. The masses of cobalt, nickel, and manganese in the magnetic substances and non - magnetic substances obtained by the second wet magnetic separation in Example 3; and the recovery rates of cobalt, nickel, and manganese in the wet magnetic separation are shown in Table 1. (Example 4) In Example 4, except that the temperature of the reheating treatment was set to 850°C, and the reheated product was micro-crushed under the same conditions as in Example 2, a concentrate of cobalt and nickel (magnetic material from the second wet magnetic separation) was obtained in the same manner as in Example 3. The masses of cobalt, nickel, and manganese in the magnetic and non-magnetic materials obtained from the second wet magnetic separation in Example 4; and the recovery rates of cobalt, nickel, and manganese in the wet magnetic separation are shown in Table 1. When observing and comparing the states of the magnetic materials from the second wet magnetic separation in Example 3 and Example 4 by SEM, in Example 3, to some extent, there were parts where the lumps of cobalt and nickel grown by the reheating treatment and the manganese oxide were condensed and present. In contrast, in Example 4, by crushing the product after the reheating treatment, the physical condensation state between the metals of cobalt and nickel and the manganese oxide could be more fully released. It can be seen from this that, compared with Example 3, the separability of cobalt, nickel, and manganese in the wet magnetic separation of Example 4 was further improved. In other words, compared with Example 3, in Example 4, more cobalt and nickel could be recovered on the magnetic material side, and more manganese could be recovered on the non-magnetic material side. (Examples 5 to 7) In Examples 5 to 7, except that the temperature (850°C or 1000°C) and time (1 hour or 4 hours) of the reheating treatment were changed to the conditions of the temperature and time shown in Table 1, a concentrate of cobalt and nickel was obtained in the same manner as in Example 4. The masses of cobalt, nickel, and manganese in the magnetic and non-magnetic materials obtained from the second wet magnetic separation in Examples 5 to 7; and the recovery rates of cobalt, nickel, and manganese in the wet magnetic separation are shown in Table 1. From the results of Examples 5 to 7, it is preferred to increase the temperature of the reheating treatment and extend the heat treatment time. (Examples 8 and 9) In Example 8, a concentrate of cobalt and nickel was obtained in the same manner as in Example 4, except that the fine-grained product passing through the sieve was not subjected to reheating treatment. In Example 9, a concentrate of cobalt and nickel was obtained in the same manner as in Example 4, except that the fine-grained product passing through the sieve was not subjected to reheating treatment and not subjected to micro-crushing by a vibration mill. The masses of cobalt, nickel, and manganese in the magnetic and non-magnetic materials obtained from the second wet magnetic separation in Examples 8 to 9; and the recovery rates of cobalt, nickel, and manganese in the magnetic separation are shown in Table 1. From the results of Examples 4, 8, and 9, it was confirmed that by performing the reheating treatment, the recovery rate and quality of the magnetic materials of cobalt and nickel could be further improved. Also, it was confirmed that micro-crushing such as by a vibration mill also had the effect of improving the recovery rate and quality of the magnetic materials of cobalt and nickel. From the above results, in the present invention, it was confirmed that it was preferred to perform the reheating treatment and micro-crushing in combination. (Example 10) In Example 10, by the same method as in the above examples, it was confirmed that cobalt and nickel could be concentrated and manganese could be separated in the positive electrode material product itself in the lithium-ion secondary battery and in the batch positive electrode materials discharged during the manufacturing process of the lithium-ion secondary battery. Therefore, the positive electrode material (a reagent for a ternary positive electrode material for a 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 used as the target for processing. In Example 10, first, carbon was added to the above positive electrode material, and in a reducing atmosphere (a state in which carbon was placed in a container as a reducing agent and covered), heat treatment was performed at 1000 °C for 1 hour (equivalent to the reheating treatment in Examples 1 to 9). When the positive electrode material after heat treatment was confirmed in Example 10, it was confirmed that cobalt and nickel formed metallic lumps. Next, in Example 10, in the same manner as in Example 2, wet magnetic separation (separation of magnetic substances and non-magnetic slurries using a drum-type magnetic separator) was performed on the positive electrode material after heat treatment. Subsequently, when the obtained magnetic substances were 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 cathode material using lithium manganate) as the cathode material was used as the object to be processed. Also, in Example 11, wet magnetic separation (the first wet magnetic separation in Example 9) was not performed on the fine-grained product separated by screening of the pulverized product after heat treatment of the lithium-ion secondary battery pack, and except that when further performing wet magnetic separation on the reheated product obtained by reheating treatment, ultrasonic particle dispersion treatment was not performed and no dispersant was added, in the same manner as in Example 9, concentrates of cobalt and nickel were obtained. In Example 12, wet magnetic separation (the first wet magnetic separation in Example 9) was not performed on the fine-grained product separated by screening of the pulverized product after heat treatment of the lithium-ion secondary battery pack, and except that when further performing wet magnetic separation on the reheated product obtained by reheating treatment, ultrasonic particle dispersion treatment was not performed, in the same manner as in Example 9, concentrates of cobalt and nickel were obtained. In Example 13, wet magnetic separation (the first wet magnetic separation in Example 9) was not performed on the fine-grained product separated by screening of the pulverized product after heat treatment of the lithium-ion secondary battery pack, and except that when further performing wet magnetic separation on the reheated product obtained by reheating treatment, no dispersant was added, in the same manner as in Example 9, concentrates of cobalt and nickel were obtained. In Example 14, except that wet magnetic separation (the first wet magnetic separation in Example 9) was not performed on the fine-grained product separated by screening of the pulverized product after heat treatment of the lithium-ion secondary battery pack, in the same manner as in Example 9, concentrates of cobalt and nickel were obtained. From the evaluation results of Examples 11 to 14, ultrasonic particle dispersion treatment and the addition of a dispersant respectively affect the quality of cobalt and nickel obtained by wet magnetic separation. The masses of cobalt, nickel, and manganese in the magnetic and non-magnetic substances obtained by wet magnetic separation in Examples 11 to 14; and the recovery rates of cobalt, nickel, and manganese in wet magnetic separation are shown in Table 1. From this result, in order to improve the quality of cobalt and nickel obtained by wet magnetic separation, it was confirmed that it is better to use ultrasonic waves and a dispersant in combination. (Example 15) In Example 15, except that after pulverizing and classifying the heat-treated product obtained after heat treatment, the fine-grained product separated by screening of the pulverized product was micro-pulverized by a vibration mill under the same conditions as in Example 8, in the same manner as in Example 14, concentrates of cobalt and nickel were obtained. The masses of cobalt, nickel, and manganese in the magnetic and non-magnetic substances obtained by wet magnetic separation in Example 15; and the recovery rates of cobalt, nickel, and manganese in wet magnetic separation are shown in Table 1. Compared with Example 14, the masses of cobalt and nickel in the magnetic substance of Example 15 were further improved. (Example 16) In Example 16, a lithium ion secondary battery pack using LMO as the positive electrode material was used as the object to be treated. Except that wet magnetic separation (the first wet magnetic separation in Example 7) was not performed on the fine particle product separated by screening under the sieve of the crushed product after heat treatment of the lithium ion secondary battery pack, the same as in Example 7, concentrates of cobalt and nickel were obtained. The masses of cobalt, nickel, and manganese in the magnetic and non-magnetic substances obtained by wet magnetic separation in Example 16; and the recovery rates of cobalt, nickel, and manganese in wet magnetic separation are shown in Table 1. Compared with Examples 11 to 15, the masses of cobalt and nickel in the magnetic substance of Example 16 are the highest. From this result, the same as in Example 7, reheating treatment was performed in a reducing atmosphere, and after fine pulverization with a vibration mill, ultrasonic particle dispersion treatment and wet magnetic separation using a dispersant were performed on the heat-treated product after fine pulverization, and cobalt and nickel could be concentrated preferably. (Examples 17 and 18) In Example 17, for a lithium ion secondary battery pack using LMO as the positive electrode material, heat treatment and pulverization were performed under the same conditions as in Example 1. The dust containing cobalt and nickel generated during pulverization was collected and finely pulverized using a vibration mill, and then wet magnetic separation was performed in the same manner as in Example 1 to obtain concentrates of cobalt and nickel. Also, in Example 18, except that for a lithium ion secondary battery pack using LMO as the positive electrode material, heat treatment and pulverization were performed under the same conditions as in Example 1, the dust containing cobalt and nickel generated during pulverization was collected, and reheating treatment was performed for 4 hours for reheating treatment, and then the treatment after reheating treatment was performed in the same manner as in Example 2 to obtain concentrates of cobalt and nickel. The masses of cobalt, nickel, and manganese in the magnetic and non-magnetic substances obtained by wet magnetic separation in Examples 17 and 18; and the recovery rates of cobalt, nickel, and manganese in wet magnetic separation are shown in Table 1. From these results, it was found that the collected dust generated during pulverization also contains cobalt and nickel metals, and it was confirmed that these metals could be concentrated. Also, by reheating treatment, the agglomerates of cobalt and nickel could be made larger, and it was confirmed that cobalt and nickel could be further concentrated. (Reference Example 1) In Reference Example 1, except that heat treatment was performed using an oxidizing atmosphere, the same treatment as in Example 10 was performed, and it was confirmed whether cobalt and nickel metals were generated. When the fine particle product after heat treatment was confirmed using an X-ray diffractometer (Ultima IV, manufactured by Rigaku Corporation), only LiNi x Co y Mn z O 2((x + y + z = 1), x = 0.33, y = 0.33, z = 0.33) peaks, and no peaks of cobalt and nickel metals were confirmed. That is, it was confirmed that cobalt and nickel were oxidized and remained as oxides, and no metal agglomerates were formed, and magnetic separation could not be performed. Figure 7 shows the X-ray diffraction peaks (spectra) of the cathode material oxide form without forming cobalt and nickel metals in Reference Example 1. (Reference Example 2) In Reference Example 2, except that the heat treatment temperature during heat treatment was set to 550 °C, the same treatment as in Example 10 was performed, and it was confirmed whether cobalt and nickel metals were generated. When confirming the fine-grained product after heat treatment using an X-ray diffractometer (manufactured by Rigaku Corporation, Ultima IV), LiNi x Co y Mn z O 2 ((x + y + z = 1), x = 0.33, y = 0.33, z = 0.33) peaks and carbon peaks, and no peaks of cobalt and nickel metals were confirmed. That is, it was confirmed that the state where no metal agglomerates (or almost no metal agglomerates) were formed, and magnetic separation could not be performed. Figure 8 shows the X-ray diffraction peaks (spectra) of the cathode material oxide form without forming cobalt and nickel metals in Reference Example 2. [Table 1] In addition, Tables 2 to 5 below show a summary of the processing conditions and the like of each example. [Table 2] [Table 3] [Table 4] [Table 5] (Investigation of heat treatment temperature) Regarding the heat treatment temperature of the battery pack, it was confirmed using a thermogravimetric differential thermal analyzer (manufactured by Rigaku Corporation) that cobalt and nickel metals were generated at 750 °C to 1200 °C. Specifically, a mixture with a weight ratio of carbon to the ternary cathode material (molar ratio of cobalt, nickel, and manganese is 1:1:1) of 3:7 was analyzed using a thermogravimetric differential thermal analyzer. Regarding the measurement conditions, the measurement was performed in a nitrogen atmosphere with a heating rate of 20 °C / minute. Figure 9 shows the results of analyzing a mixture with a weight ratio of carbon to ternary cathode material of 3:7 for investigating the heat treatment temperature using a thermogravimetric differential thermal analyzer. In Figure 9, the vertical axis represents the change in mass (weight: TG curve) and the temperature difference (heat flow; DTA curve), and the horizontal axis represents the temperature. In the example shown in Figure 9, endothermic reaction starts around 400 °C, and weight loss occurs around 750 °C. The state where weight loss and endothermic reaction occur simultaneously is characteristic of a reduction reaction. It can be seen that this is the reduction reaction of carbon in the cathode material reagent being analyzed. The following reactions can be considered as the reactions occurring in this example. 2LiMO 2 + C → Li 2 O + 2MO + CO MO + C → M + CO (Here, M is a complex of cobalt, nickel, and manganese, or a single entity of any one of them) It can be seen that in order to promote the metallization of cobalt and nickel using the reduction reaction in contact with carbon, it is preferably heat-treated at 750 °C or higher. (Investigation of the reheat treatment temperature) Next, using the above thermogravimetric differential thermal analyzer, the temperature of the reheat treatment that causes the metallization of cobalt and nickel is verified. In this verification, the lithium-ion secondary battery as a sample (target) is heat-treated, crushed, and sieved (classified), and the fine-grained product sorted under the sieve is obtained and supplied to the thermogravimetric differential thermal analyzer. The measurement atmosphere at this time is the same as that in the above embodiment. It is assumed that a reducing atmosphere is generated by the lid, and under the condition that there is not completely no air, although oxygen is not actively supplied, because there is oxygen around the sample and carbon coexists as a powder to form a reducing atmosphere state, the measurement is carried out in an air atmosphere. The heating rate is 20 °C per minute. Figure 10 shows the results of analyzing the fine-grained product obtained by heat-treating, crushing, and classifying a lithium-ion secondary battery for investigating the reheat treatment temperature using a thermogravimetric differential thermal analyzer. As shown in Figure 10, weight loss and exothermic reaction occur around just above 300 °C, and carbon combustion is confirmed. At this time, cobalt and nickel compounds are reduced by CO (carbon monoxide) accompanying the combustion, and a metallization reaction occurs. The following reactions can be considered as the reactions occurring in this example. 2C + O 2 → 2CO MO + CO → M + CO 2 (Here, M is a complex of cobalt, nickel, and manganese, or a single entity of any one of them) It can be seen that it is preferably reheat-treated at 300 °C or higher. None. [Figure 1] Figure 1 shows a scanning electron microscope (SEM, manufactured by Hitachi High-Technologies Corporation, TM4000Plus) photograph of an example of a part of the fine-grained product (including the positive electrode material) obtained after heat treatment, pulverization, and sieving of the ternary lithium-ion secondary battery containing cobalt, nickel, and manganese in the embodiment of the present invention. All the SEM photographs in the drawings of the present invention were taken using the same device. [Figure 2] Figure 2 shows an SEM photograph of another example of a part of the fine-grained product (including the positive electrode material) obtained after heat treatment, pulverization, and sieving of the ternary lithium-ion secondary battery containing cobalt, nickel, and manganese in the embodiment of the present invention. [Figure 3A] Figure 3A shows an SEM photograph of an example of a part of the fine-grained product (including the positive electrode material) obtained by reheating at 1000 °C in the presence of carbon after heat treatment, pulverization, and sieving of the ternary lithium-ion secondary battery containing cobalt, nickel, and manganese in the embodiment of the present invention. [Figure 3B] Figure 3B shows a graph of the elemental peaks of the EDS (energy-dispersive X-ray spectroscope, manufactured by Oxford University Press, AZtecone) of the agglomerates in an example of a part of the fine-grained product (including the positive electrode material) obtained by reheating at 1000 °C in the presence of carbon after heat treatment, pulverization, and sieving of the ternary lithium-ion secondary battery containing cobalt, nickel, and manganese in the embodiment of the present invention. All the elemental peaks of the EDS in the drawings of the present invention were obtained using the same device. [Figure 3C] Figure 3C shows a graph of the elemental peaks of the EDS (energy-dispersive X-ray spectroscope) of manganese oxide in an example of the fine-grained product (including the positive electrode material) obtained by reheating at 1000 °C in the presence of carbon after heat treatment, pulverization, and sieving of the ternary lithium-ion secondary battery containing cobalt, nickel, and manganese in the embodiment of the present invention. [Figure 3D] Figure 3D shows an SEM photograph of the appearance of agglomerate formation after 1 hour in the 2-hour reheating treatment step in the embodiment of the present invention. [Figure 4A] Figure 4A shows an SEM photograph of an example of the fine-grained product before wet magnetic separation in the embodiment of the present invention. [Figure 4B] Figure 4B shows a graph of the elemental peaks of the EDS (energy-dispersive X-ray spectroscope) of an example of the fine-grained product before wet magnetic separation in the embodiment of the present invention. [Figure 4C] Figure 4C shows a graph of the elemental peaks of the EDS (energy-dispersive X-ray spectroscope) of an example of the fine-grained product before wet magnetic separation in the embodiment of the present invention. [Figure 5A] Figure 5A shows an SEM photograph of an example of the fine-grained product after wet magnetic separation in the embodiment of the present invention. [Figure 5B] Figure 5B shows a graph of the elemental peaks of the EDS (energy-dispersive X-ray spectroscope) of an example of the fine-grained product after wet magnetic separation in the embodiment of the present invention. [Figure 5C] Figure 5C shows a graph of the elemental peaks of the EDS (energy-dispersive X-ray spectroscope) of an example of the fine-grained product after wet magnetic separation in the embodiment of the present invention.[Fig. 6A] Fig. 6A is an SEM photograph taken of an example of particles obtained after fine pulverization of a lump of metal and oxide in an embodiment of the present invention. [Fig. 6B] Fig. 6B is a graph showing elemental peaks obtained by performing elemental analysis using EDS (energy dispersive X-ray spectroscope) on a part of particles a of cobalt and nickel metallized in Fig. 6A in an embodiment of the present invention. [Fig. 6C] Fig. 6C is a graph showing elemental peaks obtained by performing elemental analysis using EDS (energy dispersive X-ray spectroscope) on a part of particles a of cobalt and nickel metallized in Fig. 6A in an embodiment of the present invention. [Fig. 7] Fig. 7 is a graph showing an example of an X-ray diffraction peak in Reference Example 1 where cobalt and nickel metals are not formed but the positive electrode material remains in the oxide form. [Fig. 8] Fig. 8 is a graph showing an example of an X-ray diffraction peak in Reference Example 2 where cobalt and nickel metals are not formed but the positive electrode material remains in the oxide form. [Fig. 9] Fig. 9 is a graph showing an example of the result of analyzing a mixture of carbon and a ternary positive electrode material with a weight ratio of 3:7 using a thermogravimetric differential thermal analyzer for investigating the heat treatment temperature. [Fig. 10] Fig. 10 is a graph showing an example of the result of analyzing the fine particle product obtained after heat treatment, pulverization, and classification of a lithium ion secondary battery using a thermogravimetric differential thermal analyzer for investigating the reheat treatment temperature. None.

Claims

1. A method for concentrating valuable metals contained in a lithium-ion secondary battery, characterized by comprising: the method for concentrating valuable metals contained in a lithium-ion secondary battery is to process a lithium-ion secondary battery or its positive electrode material containing at least one element selected from cobalt and nickel and manganese oxide, to concentrate at least one valuable metal containing cobalt and nickel; a heat treatment step, which involves heating the aforementioned lithium-ion secondary battery or its positive electrode material to 600°C to 1200°C; a pulverizing and classifying step, which involves pulverizing and classifying the heat-treated material obtained in the aforementioned heat treatment step; and a reheating step, which involves reheating the fine-particle product obtained in the aforementioned pulverizing and classifying step to 700°C to 1200°C to form granules of manganese oxide and at least one valuable metal containing cobalt and nickel.

2. A method for concentrating valuable metals contained in a lithium-ion secondary battery as described in claim 1, wherein, The aforementioned negative electrode material for lithium-ion secondary batteries includes carbon.

3. A method for concentrating valuable metals contained in a lithium-ion secondary battery as described in claim 1 or 2, wherein, It also includes: a sorting step, which involves sorting and recovering a product concentrated with at least one of cobalt and nickel from the aforementioned reheated product obtained in the aforementioned reheating step.

4. A method for concentrating valuable metals contained in a lithium-ion secondary battery as described in claim 3, wherein, The aforementioned sorting step is to recover products concentrated with at least one of cobalt and nickel, as well as products concentrated with manganese.

5. A method for concentrating valuable metals contained in a lithium-ion secondary battery as described in claim 3, wherein, The aforementioned sorting steps are steps that utilize differences in at least one of magnetism, particle size, and specific gravity for separation.

6. A method for concentrating valuable metals contained in a lithium-ion secondary battery as described in claim 1, wherein, In the aforementioned heat treatment step, the lithium-ion secondary battery is housed in an aluminum-containing casing, and the aluminum is separated from the casing during heating.

7. A method for concentrating valuable metals contained in a lithium-ion secondary battery as described in claim 1, wherein, In the aforementioned crushing and grading steps, the pulverized material is subjected to impact, shearing, or compression, and then graded using a sieve with a mesh size of 0.1 mm to 2.4 mm.

8. A method for concentrating valuable metals contained in a lithium-ion secondary battery as described in claim 1, wherein, In the aforementioned reheating process, the cumulative 50% volumetric particle size D50 of the aforementioned pellets containing at least one metal, cobalt and nickel, is 1 μm or more.

9. A method for concentrating valuable metals contained in a lithium-ion secondary battery as described in claim 3, wherein, The aforementioned sorting step is a magnetic sorting step, and the magnetic flux density of the magnet in the aforementioned magnetic sorting step is above 0.01 Tesla and below 2 Tesla.

10. A method for concentrating valuable metals contained in a lithium-ion secondary battery as described in claim 9, wherein, The aforementioned magnetic separation step is a wet magnetic separation, and for the slurry to which the aforementioned wet magnetic separation is applicable, a dispersant of 50 mg / L or more is added.

11. A method for concentrating valuable metals contained in a lithium-ion secondary battery as described in claim 10, wherein, For the slurry applicable to the aforementioned wet magnetic separation, ultrasonic particle dispersion treatment is performed.

12. A method for concentrating valuable metals contained in a lithium-ion secondary battery as described in claim 1, wherein, In at least one of the aforementioned heat treatment steps and the aforementioned reheating treatment steps, a reducing component is added and a reducing atmosphere is formed.

13. A method for concentrating valuable metals contained in a lithium-ion secondary battery as described in claim 1, wherein, In the aforementioned heat treatment step or the aforementioned reheating treatment step, a portion of the heat treatment time is spent heating in an air atmosphere or an oxidizing atmosphere, thereby reducing the mass of the reducing components in the heat-treated or reheat-treated product.

14. A method for concentrating valuable metals contained in a lithium-ion secondary battery as described in claim 3, wherein, After the aforementioned reheating treatment step and before the aforementioned sorting step, a re-crushing step is performed on the heat-treated material.

15. A method for concentrating valuable metals contained in a lithium-ion secondary battery as described in claim 1, wherein, The fine particles obtained from the aforementioned pulverization and grading steps are subjected to a magnetic separation step using magnetic force; and the magnetic material obtained from the aforementioned magnetic separation step is subjected to the aforementioned reheating treatment step.

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