JP6676124B1 - Method of recovering valuable resources from lithium ion secondary batteries - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide means for recovering valuable materials such as cobalt, nickel and copper with low impurity quality and high recovery rate. A heat treatment step of heat-treating a lithium ion secondary battery, a crushing step of crushing the heat-treated product obtained in the heat treatment step, and a crushed product obtained in the crushing step are made to be 1.2 to 2.4 mm. The first-stage classification step of classifying at the classification point of, and the second-stage classification of classifying the intermediate product and the fine-grained product obtained on the narrow side in the first classification step at a classification point of 0.3 mm or less And a dry magnetic separation step in which the intermediate product obtained on the rough side in the second classification step is subjected to dry magnetic separation, and the obtained magnetic substance is again subjected to dry magnetic separation at least once. A method of recovering valuable materials from a lithium ion secondary battery. [Selection diagram] Fig. 1

Description

  The present invention can recover valuable materials from the positive electrode current collector, the negative electrode current collector, the positive electrode active material, etc. of the lithium ion secondary battery which is discarded due to defective products generated during the manufacturing process, the life of the used equipment and the battery, etc. The present invention relates to a method for recovering valuable resources from a lithium ion secondary battery.

Lithium-ion rechargeable batteries are lightweight, high-capacity, high-electromotive force rechargeable batteries compared to conventional lead-acid batteries, NiCd rechargeable batteries, etc., and are used as rechargeable batteries for personal computers, electric vehicles, portable devices, etc. Have been. For example, the positive electrode of the lithium ion secondary battery, valuable materials, such as cobalt or nickel, lithium cobaltate (LiCoO _2), ternary positive electrode material _{(LiNi x Co y Mn z O} 2 (x + y + z = 1)) , etc. Has been used as

  Since the use of the lithium ion secondary battery is expected to continue to expand in the future, it is possible to recover valuable resources from lithium ion secondary batteries that are discarded due to defective products generated during the manufacturing process or the life of the equipment and battery. Recovery is desired from the viewpoint of resource recycling. When recovering valuable resources from a lithium ion secondary battery, it is important to separate and recover various metals used from the viewpoint of increasing the value of the recovered material.

  As a method of recovering valuable resources from a lithium ion secondary battery, a method of recovering cobalt and nickel from a crushed product of a heat-treated lithium ion battery has been proposed. For example, Patent Literature 1 discloses a method of recovering cobalt by heat-treating and pulverizing a used lithium secondary battery, sieving the pulverized material, and magnetically sorting under the sieve.

Japanese Patent No. 3444346

  When the lithium ion secondary battery is heat-treated and then crushed and classified, metals derived from the outer container or member such as iron and metals derived from the current collector such as copper are collected as coarse-grained products. Further, although cobalt nickel is concentrated in the fine-grained product, a part of the metal derived from the current collector is also mixed into the fine-grained product. For cobalt / nickel recycling, there is a demand for separation and recovery of current collector-derived metals and negative electrode active materials from fine-grained products. Since the active material has a structure that is bonded to the current collector with a binder, it is necessary to decompose the binder and separate the current collector from the active material in order to collect the current collector and active material with high quality. It is. According to the method described in Patent Literature 1, (1) the use of shear crushing results in poor separation of the active material from the current collector except for the portion where the shear blade contacts during crushing, and (2) The magnetic separation performance is insufficient and the carbon quality derived from the negative electrode active material in the cobalt concentrate is high. (3) Metals derived from the negative electrode current collector such as copper of lithium ion secondary batteries are not only valuable materials but also cobalt -Separation and recovery are desired because they are impurities in nickel recycling, but there is a problem that a method for separating and recovering a metal derived from the negative electrode current collector from cobalt and nickel has not been studied. Mainly for the reasons (1) and (2), the grade of the metal derived from the negative electrode current collector such as copper in the cobalt nickel concentrate is less than 0.2%, and the grade of the material derived from the negative electrode active material such as carbon is 5%. % Was difficult to reduce. Further, for the reason (3), it has been difficult to separate and recover 50% or more of the metal derived from the negative electrode current collector from the recovered cobalt / nickel.

  The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide means for recovering valuable materials such as metals derived from a negative electrode current collector such as cobalt nickel and copper with a low impurity grade and a high recovery rate. .

  In order to solve the above problems, according to the present invention, a heat treatment step of heat-treating a lithium ion secondary battery, a crushing step of crushing the heat-treated product obtained in the heat treatment step, and a crushing step obtained in the crushing step The first step of classifying the product at a classification point of 1.2 to 2.4 mm, and the intermediate product and fine-grain product obtained on the narrow side in the first step of classification are reduced to 0.3 mm or less. The second-stage classification step of classifying at the classification point and the step of dry-magnetic-separating the intermediate product obtained on the rough side in the second-stage classification step, and the step of dry-magnetic-separating the obtained magnetized product are repeated at least once. A method for recovering valuable resources from a lithium ion secondary battery, comprising a dry magnetic separation step is provided.

  In the heat treatment step, aluminum may be melted and separated and recovered. Further, the magnetic substance obtained in the dry magnetic separation step may have a content of a substance derived from the negative electrode active material of less than 5%. In that case, the material derived from the negative electrode active material may be carbon. Further, the magnetic substance obtained in the dry magnetic separation step may have a metal quality derived from the negative electrode current collector of less than 0.2%. In that case, the metal derived from the negative electrode current collector may be copper. Further, the heat treatment step may be performed in a low oxygen atmosphere having an oxygen concentration of 10.5% by mass or less. In addition, the method may further include a dry magnetic separation step of dry magnetic separation of the coarse-grained product obtained on the coarse side in the first-stage classification step.

  ADVANTAGE OF THE INVENTION According to this invention, when recovering a valuable resource from a lithium ion secondary battery, a valuable resource such as cobalt / nickel can be recovered with a low negative electrode collector-derived metal grade and a negative electrode active material grade.

It is a flowchart explaining the collection | recovery method concerning embodiment of this invention.

  Hereinafter, an example of an embodiment for carrying out the present invention will be described.

<Lithium ion secondary battery>
A lithium ion secondary battery is a secondary battery that performs charging and discharging by moving lithium ions between a positive electrode and a negative electrode. For example, an electrolytic cell containing a positive electrode, a negative electrode, a separator, an electrolyte and an organic solvent is used. One provided with a liquid and an outer container which is a battery case containing a positive electrode, a negative electrode, a separator, and an electrolytic solution.

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

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

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

  The positive electrode material is not particularly limited and can be appropriately selected depending on the purpose. For example, a positive electrode material containing at least a positive electrode active material containing a rare valuable material, and optionally containing a conductive agent and a binder resin And the like. The rare valuables are not particularly limited and may be appropriately selected depending on the purpose. However, it is preferable that at least one of cobalt, nickel, and manganese is used.

As the positive electrode active material, for example, lithium cobaltate (LiCoO ₂ ), lithium nickelate (LiNiO ₂ ), lithium manganate (LiMn ₂ O ₄ ), lithium cobalt nickelate (LiCo _1/2 Ni _1/2 O ₂ ) , LiNi _x Co _y Mn _z O ₂ and their respective composites.

  The conductive agent is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include carbon black, graphite, carbon fiber, and metal carbide.

  The binder resin is not particularly limited and can be appropriately selected depending on the intended purpose.Examples include homopolymers or copolymers of vinylidene fluoride, ethylene tetrafluoride, acrylonitrile, and ethylene oxide, and styrene-butadiene rubber. And the like.

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

  The shape, structure, size, material, and the like of the negative electrode current collector are not particularly limited, and can be appropriately selected depending on the purpose. Examples of the shape of the negative electrode current collector include a foil shape. Examples of the material of the negative electrode current collector include stainless steel, nickel, aluminum, copper, titanium, and tantalum. Among these, copper is preferred.

  The negative electrode material is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include carbon materials such as graphite and hard carbon, titanate, silicon, and composites thereof.

  Note that the positive electrode current collector and the negative electrode current collector have a laminated structure, and the laminated body is not particularly limited and can be appropriately selected depending on the purpose.

  In the embodiment of the present invention, according to the procedure shown in FIG. 1, a metal derived from an outer container such as aluminum and iron, a metal derived from a positive electrode active material such as cobalt and nickel, and a negative electrode current collector such as copper are contained in a lithium ion secondary battery. Efficient separation and recovery of body-derived metals. The lithium ion secondary battery used for recovery is not particularly limited and can be appropriately selected depending on the purpose.For example, a defective lithium ion secondary battery generated in the process of manufacturing a lithium ion secondary battery, Examples include a lithium ion secondary battery that is discarded due to a failure of a used device or the life of the used device, a used lithium ion secondary battery that is discarded due to a life, and the like.

<Heat treatment process>
As shown in FIG. 1, first, a heat treatment step is performed on a lithium ion secondary battery. The heat treatment temperature is not particularly limited as long as it is a temperature equal to or higher than the melting point of the current collector having a low melting point and lower than the melting point of the current collector having a high melting point, between the positive electrode current collector and the negative electrode current collector. 670 ° C. or higher, preferably 670 ° C. or higher and 1100 ° C. or lower, more preferably 700 ° C. or higher and 900 ° C. or lower. When the heat treatment temperature is lower than 670 ° C., the low melting point current collector may not be sufficiently embrittled. When the heat treatment temperature exceeds 1100 ° C., the low melting point current collector, the high melting point current collector, and Any of the outer containers becomes brittle, and the efficiency of separation of the current collector from the cobalt nickel concentrate by crushing and classification decreases. Further, when the outer container of the lithium ion secondary battery is melted during the heat treatment, by placing a tray for collecting the molten metal below the lithium ion secondary battery, the metal and the electrode derived from the outer container are disposed. The parts can be easily separated.

  By performing the heat treatment at a predetermined heat treatment temperature, for example, in a laminate in which the positive electrode current collector is aluminum and the negative electrode current collector is copper, the positive electrode current collector made of aluminum foil is embrittled, and a crushing step described below is performed. , It becomes easy to refine. This embrittlement of the positive electrode current collector is caused by a melting or oxidation reaction. In addition, the aluminum that has melted and flowed down is collected in a tray. On the other hand, since the negative electrode current collector made of copper is heat-treated at a temperature lower than the melting point of copper, it does not melt and can be highly sorted in a dry magnetic separation step described later. Further, when any one of the laminate and the lithium ion secondary battery is housed in an oxygen shielding container and heat-treated, the positive electrode current collector made of aluminum foil is melted and embrittled, and is easily granulated in a crushing step described later. On the other hand, the negative electrode current collector made of copper has a low oxygen partial pressure due to the oxygen shielding effect of the oxygen shielding container and the reduction effect of the negative electrode active material such as carbon contained in the laminate or the lithium ion secondary battery. , So that embrittlement due to oxidation does not occur. For this reason, by the crushing in the crushing step, the positive electrode current collector is finely crushed, and the negative electrode current collector is still present as coarse particles even after crushing. In the first-stage classification step and the second-stage classification step described below, Become more effective and highly selective.

  The heat treatment time is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 1 minute or more and 5 hours or less, more preferably 1 minute or more and 2 hours or less, and particularly preferably 1 minute or more and 1 hour or less. . The heat treatment time may be a heat treatment time for the current collector having a low melting point to reach a desired temperature, and the holding time may be short. When the heat treatment time is within a particularly preferable range, it is advantageous in terms of cost for heat treatment.

  The method of heat treatment is not particularly limited and can be appropriately selected depending on the purpose. For example, the heat treatment is performed using a heat treatment furnace. Examples of the heat treatment furnace include a batch kiln such as a rotary kiln, a fluidized bed furnace, a tunnel furnace, and a muffle, a cupola, and a stalker furnace.

The atmosphere used for the heat treatment is not particularly limited and can be appropriately selected depending on the intended purpose; however, the heat treatment can be performed in the air. It is preferable to use an atmosphere having a low oxygen concentration, since a metal derived from the positive electrode current collector and a metal derived from the negative electrode current collector can be recovered with high quality and a high recovery rate.
Specifically, a low oxygen atmosphere having an oxygen concentration of 10.5% by mass or less is preferable because a metal derived from the positive electrode current collector and a metal derived from the negative electrode current collector can be recovered with high quality and a high recovery rate. It is desirable to suppress the oxidation of the valuable metal of the lithium ion secondary battery by performing the heat treatment step in an atmosphere in which the oxygen concentration is adjusted to be low (low oxygen atmosphere). That is, cobalt present as LiCoO ₂ (diamagnetic material) can be converted to cobalt metal (ferromagnetic material) by heat treatment and reduction in the coexistence of the negative electrode active material.

  As a method for realizing the low oxygen atmosphere, a lithium ion secondary battery or a laminate may be housed in an oxygen shielding container and heat-treated. The material of the oxygen shielding container is not particularly limited as long as the material has a melting point equal to or higher than the melting point of the high-melting current collector among the positive electrode current collector and the negative electrode current collector, and is appropriately selected depending on the purpose. For example, when the positive electrode current collector is aluminum and the negative electrode current collector is copper, iron, stainless steel, or the like having a melting point higher than 660.32 ° C., which is the melting point of aluminum, may be used. It is preferable to provide an opening in the oxygen shielding container in order to release the gas pressure due to the combustion of the electrolyte in the lithium ion battery or the laminate. The opening area of the opening is preferably provided so as to be 12.5% or less based on the surface area of the outer container provided with the opening. The opening area of the opening is more preferably 6.3% or less based on the surface area of the outer container provided with the opening. When the opening area of the opening exceeds 12.5% of the surface area of the outer container, most of the current collector is easily oxidized by the heat treatment. There is no particular limitation on the shape, size, location of the opening, and the like, and the opening can be appropriately selected depending on the purpose.

<Crushing process>
Next, a crushing step of crushing the heat-treated product obtained in the heat treatment step is performed. In the crushing step, it is preferable to crush the heat-treated product by impact to obtain a crushed product.

  The crushing is not particularly limited and can be appropriately selected according to the purpose. Examples of the method of crushing by impact include a method of throwing with a rotating hitting plate and hitting against a collision plate to give an impact, and a method of hitting a heat-treated product with a rotating hitter (beater), such as a hammer crusher or a chain. It can be performed by a crusher or the like. In addition, a method of hitting a heat-treated material with a ball or rod of ceramic or iron, for example, can be used, and can be performed by a ball mill, a rod mill, or the like. Further, the crushing can be performed by crushing with a twin-screw crusher having a short blade width and a short blade for crushing by compression.

  By obtaining the crushed product by the impact, the active material and the current collector are favorably separated from each other. In addition, since the active material is originally a particle of several tens of nanometers, the current collector has a foil-like shape, so that the active material is preferentially disintegrated by impact crushing, and as a result, separated by sieving. it can.

  The crushing time is not particularly limited and may be appropriately selected depending on the purpose. The processing time per 1 kg of the lithium ion secondary battery is preferably 1 second or more and 30 minutes or less, more preferably 2 seconds or more and 10 minutes or less. It is preferably from 3 seconds to 5 minutes. If the crushing time is less than 1 second, the crushing may not be performed, and if the crushing time exceeds 30 minutes, the crushing may be excessively performed.

<First stage classification process>
Next, a first classifying step of classifying the crushed product obtained in the crushing step into a coarse product, an intermediate product and a fine product is performed. The classification method is not particularly limited and can be appropriately selected depending on the purpose. For example, the classification is performed using a vibrating sieve, a multistage vibrating sieve, a cyclone, a JIS Z8801 standard sieve, a wet vibration table, an air table, or the like. be able to.

  As a classification point used in the first-stage classification step, a sieve having an opening of 1.2 to 2.4 mm is used. When the classification point exceeds 2.4 mm, the mixing of the metal from the outer container and the higher melting point into the fine-grained product increases, and the separation performance from the active material-derived cobalt / nickel decreases. On the other hand, when the classification point is less than 1.2 mm, the mixing of the metal and active material from the low melting point current collector into the coarse product increases, and the metal from the high melting point current collector in the coarse particle product increases. And the recovery rate of cobalt / nickel derived from the positive electrode active material in fine-grained products is reduced.

<Second stage classification>
A second-stage classification process is performed on the intermediate product and fine-grain product obtained on the fine side in the first-stage classification process, and an intermediate product containing a cathode active material-derived metal such as cobalt or nickel on the coarse side. The product is recovered and the fine product containing carbon on the fine side is recovered. A classification point having a classification point of 0.3 mm or less is used as a mesh opening of the sieve used in the second-stage classification step. When the classification point exceeds 0.3 mm, the incorporation of cobalt nickel into the fine-grained product increases, and the recovery rate of cobalt nickel into the intermediate product decreases.

  By these classifications, the metal derived from the outer container and the high melting point current collector as a coarse-grained product, the intermediate product containing a positive electrode active material such as cobalt and nickel as an intermediate product, and the negative electrode active material such as carbon as a fine-grained product Can be separated and recovered.

  When a sieve is used as a classifying method, the foil-shaped current collector is also a crushing accelerator, for example, by sieving a stainless steel ball or alumina ball on the sieve, a small amount of the residue remaining on the sieve is reduced. By crushing and atomizing the current collector having the melting point, the quality of the metal of the outer container and the current collector having a high melting point in the coarse-grained product can be further improved.

<Dry magnetic separation process for coarse-grained products>
Next, a dry magnetic separation step may be performed on the coarse-grained product obtained on the coarse side in the first-stage classification step. In this case, iron can be recovered as a magnetic substance, and a metal derived from the high melting point current collector such as copper can be recovered as a non-magnetic substance.

<Dry magnetic separation process for intermediate products>
The intermediate product obtained on the coarse side in the second-stage classification step is subjected to a second-stage dry magnetic separation step in which the magnetically collected product collected in the first-stage magnetic separation is again subjected to a second-stage magnetic separation. Will be Cobalt / nickel is recovered as a magnetized material, and copper and carbon derived from the negative electrode material are transferred to the non-magnetic material. By this magnetic separation, for example, when the negative electrode current collector is copper and the negative electrode active material is carbon, the intermediate product, that is, the negative electrode current collector-derived metal grade such as copper in the cobalt nickel concentrate is less than 0.2%, And the material quality derived from the negative electrode active material such as carbon can be reduced to less than 5%. When the dry magnetic separation is performed in one stage, the negative electrode current collector and the negative electrode active material are entangled in cobalt-nickel, and a high percentage is recovered. The source metal grade cannot be less than 0.2% or the material grade derived from the negative electrode active material cannot be less than 5%. In addition, when the intermediate product is subjected to dry magnetic separation, particles may be agglomerated due to moisture adhering between the particles, so that by performing a drying treatment or the like after the second-stage classification step as necessary, the material derived from the negative electrode material can be obtained. Metal and cobalt nickel particles can be separated sufficiently.

<Re-crushing and magnetic separation of dry magnetic separation magnetism>
The metal from the negative electrode current collector, which should be originally recovered as a non-magnetic material, may be recovered in the magnetic material after the dry magnetic separation by involving cobalt, which is a magnetic material, during the impact crushing. In order to promote the separation of these particles from the magnetic substance, the magnetic material derived from the negative electrode current collector in the cobalt / nickel concentrate can be reduced by re-crushing the magnetized material after magnetic separation and performing magnetic separation again.

  Hereinafter, examples of the present invention will be described. Note that the present invention is not limited to the following examples.

  As shown in the flow of FIG. 1, 3.7 kg of a lithium ion secondary battery was subjected to a heat treatment temperature of 850 ° C. (1H rise and 2H hold) using a muffle furnace (FJ-41, manufactured by Yamato Scientific Co., Ltd.) as a heat treatment apparatus. ), A heat treatment step was performed under the conditions of an air supply rate of 5 L / min. Next, in the crushing step, using a hammer crusher (Makino type swing hammer crusher HC-20-3.7, manufactured by Makino Sangyo Co., Ltd.) as a crushing device, 50HZ (hammer peripheral speed 38 m / s), punching metal at the exit portion Was additionally crushed once under the condition of a hole diameter of 10 mm.

  Next, as a first-stage classification step, the crushed material obtained in the crushing step was sieved using a sieve having a sieve opening of 1.2 mm. After the sieving, the top (coarse side) and the bottom (fine side) of a 1.2 mm sieve were collected. The under-sieved product (intermediate product and fine-grained product) was again subjected to second-stage classification using a 0.3 mm sieve, and cobalt / nickel was recovered as the intermediate product and carbon was recovered as the fine-grained product.

  The intermediate product obtained on the second-stage classification sieve (coarse side) is in a state in which a hand magnet having a length of 150 mm and a diameter of 20 mm is used and a magnetic force of 1500 G is applied to provide an interval of 10 mm between the intermediate product and the intermediate product. , Two-stage dry magnetic separation was performed.

  In addition, the same method as the dry magnetic separation for the intermediate product obtained on the second-stage classification screen (coarse side) is applied to the coarse-grained product obtained on the first-stage classification screen (coarse side). Dry magnetic separation was performed according to the procedure.

  After measuring the weight of the magnetically and non-magnetically adhered products obtained by dry magnetic separation on the coarse and fine-grained products and the intermediate products obtained on the second-stage classifying sieve (coarse side), heating to aqua regia The sample was dissolved and analyzed using a high-frequency inductively coupled plasma emission spectrometer (iCaP6300, manufactured by Thermo Fisher Scientific) to determine the recovery rates of cobalt and nickel, and the contents of the recovered metals. Table 1 shows the results of quality analysis of magnetically and non-magnetically attached products obtained by magnetically selecting the intermediate product. Table 2 shows the recovery rate of each valuable resource in each product. In Tables 1 and 2, (%) is% by mass. In Table 2, “+” indicates on the sieve (rough side) and “−” indicates below the sieve (fine side).

  The same procedure as in Example 1 was carried out except that the opening of the second-stage sieving was 0.15 mm. The results are also shown in Tables 1 and 2.

  The same procedure as in Example 1 was carried out except that the opening of the first-stage sieving was 2.4 mm. The results are also shown in Tables 1 and 2.

(Comparative Example 1)
Example 3 was carried out in the same manner as in Example 3, except that the opening of the first-stage sieving was 4.8 mm.

(Comparative Example 2)
It carried out by the method similar to Example 1 except having set the said 2nd-stage sieve opening to 0.6 mm.

(Comparative Example 3)
The same procedure as in Example 1 was performed except that the magnetic separation was performed in one stage.

(Comparative Example 4)
The same procedure as in Example 1 was performed, except that the second-stage sieving was not performed, and dry magnetic separation was applied to the sieved material of the first-stage sieving.

  As shown in Tables 1 and 2, it was confirmed that the cobalt nickel concentrate obtained by the recovery method of the present invention had a copper grade of less than 0.2% and a carbon grade of less than 5%. In Comparative Example 1, as shown in Table 1, the iron quality in the magnetic substance exceeded 10%, and a high quality cobalt / nickel concentrate could not be obtained. In Comparative Example 2, as shown in Table 2, 50% or more of cobalt / nickel could not be recovered in the magnetized product. In Comparative Examples 3 and 4, as shown in Table 1, a cobalt nickel concentrate having a copper grade of less than 0.2% or a carbon grade of less than 5% could not be recovered.

Claims (8)

A heat treatment step of heat treating the lithium ion secondary battery,
A crushing step of crushing the heat-treated product obtained in the heat treatment step,
A first-stage classification step of classifying the crushed product obtained in the crushing step at a classification point of 1.2 to 2.4 mm, and an intermediate product and a fine product obtained on the narrow side in the first-stage classification step. A second-stage classification step of classifying the granular product at a classification point of 0.3 mm or less;
Lithium ion, characterized by having a dry magnetic separation step in which the intermediate product obtained on the coarse side in the second-stage classification step is subjected to dry magnetic separation, and the obtained magnetically adhered product is subjected to dry magnetic separation one or more times. A method for collecting valuables from secondary batteries.   2. The method for recovering valuable resources from a lithium ion secondary battery according to claim 1, wherein aluminum is melted and recovered in the heat treatment step.   3. The valuable material from the lithium ion secondary battery according to claim 1, wherein the magnetic substance obtained in the dry magnetic separation step has a content of a substance derived from a negative electrode active material of less than 5%. 4. Collection method.   The method for recovering valuable resources from a lithium ion secondary battery according to claim 3, wherein the substance derived from the negative electrode active material is carbon.   The lithium ion secondary battery according to any one of claims 1 to 4, wherein the magnetic material obtained in the dry magnetic separation step has a metal quality derived from a negative electrode current collector of less than 0.2%. How to recover valuables from secondary batteries.   The method for recovering valuable resources from a lithium ion secondary battery according to claim 5, wherein the metal derived from the negative electrode current collector is copper.   The heat treatment step is performed in a low oxygen atmosphere having an oxygen concentration of 10.5% by mass or less, wherein valuable substances from the lithium ion secondary battery according to any one of claims 1 to 6 are characterized. Collection method.   The lithium ion secondary according to any one of claims 1 to 7, further comprising a dry magnetic separation step of performing dry magnetic separation of a coarse-grained product obtained on the coarse side in the first-stage classification step. A method for collecting valuables from batteries.

Images