How to sort valuable materials

Abstract

To provide a valuables sorting method capable of easily separating cobalt and nickel from iron and copper in a lithium ion secondary battery to make it possible to obtain high quality valuables with highly concentrated cobalt and nickel at a high recovery rate.SOLUTION: A valuables sorting method includes: a heat treatment process of performing heat treatment on a lithium ion secondary battery containing valuables; a crushing process of crushing a heat-treated material obtained in the heat treatment process; and a classification process including a first classification step of classifying crushed materials obtained in the crushing process into coarse grain products and medium products at a classification point equal to or larger than 0.6 mm and equal to or smaller than 2.4 mm and a second classification step of classifying the medium products into middle grain products and fine grain products at a classification point equal to or larger than 40 μm and equal to or smaller than 300 μm.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for separating valuable materials. [Background technology]

[0002] Lithium ion secondary batteries are lighter, have a larger capacity, and have a higher electromotive force than conventional lead-acid batteries and nickel-cadmium secondary batteries, and are used in personal computers, electric vehicles, portable devices, and the like.

[0003] Since the use of lithium-ion secondary batteries is expected to continue to expand, from the perspective of resource recycling, it is desirable to recover valuable materials from lithium-ion secondary batteries that are discarded due to defective products generated during the manufacturing process, devices used, or the end of the battery life, etc. When recovering valuable materials such as cobalt, nickel, manganese, aluminum, iron, and copper from lithium-ion secondary batteries, it is important to separate and sort the various metals and impurities used in the lithium-ion secondary batteries in order to increase the value of the recovered materials.

[0004] As a technology for recovering valuable materials from lithium-ion secondary batteries, a technology has been proposed in which the lithium-ion secondary batteries are heated, crushed, and classified, and the fine product is subjected to wet magnetic separation to concentrate and recover cobalt, nickel, and the like (see, for example, Patent Document 1). In addition, a technology has been proposed in which magnetic materials such as cobalt and nickel are separated from non-magnetic materials such as copper by heating and pulverizing the material, and then magnetic separation is performed on the resulting pulverized material (see, for example, Patent Document 2). In addition, a technology has been proposed in which lithium-ion secondary batteries are heated, crushed, and classified in two stages, and the intermediate particle size product obtained from the classification is subjected to dry magnetic separation to concentrate and recover cobalt, nickel, etc. (see Patent Document 3).

[0005] However, in the conventional techniques described above, for example, cobalt, nickel, iron, etc. are magnetic materials, and when cobalt and nickel are recovered by magnetic force, iron may also be recovered and mixed in. Therefore, there is a problem that the valuable material obtained by concentrating cobalt and nickel from the obtained lithium-ion secondary battery has a high iron content. In addition, there is also a problem that non-magnetic materials such as copper and aluminum are entangled and recovered together with magnetic materials by magnetic separation if their amounts are large. There is also a problem that the amount of cobalt and nickel recovered into medium particle size particles is low. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 6748274 [Patent Document 2] Patent No. 6268130 [Patent Document 3] Patent No. 6676124 Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention aims to solve the above-mentioned problems in the prior art and to achieve the following objectives: That is, the present invention aims to provide a method for separating valuable materials, which can easily separate cobalt and nickel from iron and copper from a lithium ion secondary battery and can obtain high-quality valuable materials with increased concentrations of cobalt and nickel at a high recovery rate. [Means for solving the problem]

[0008] The means for solving the above problems are as follows. <1> A heat treatment step of heat treating a lithium ion secondary battery containing valuable materials; A crushing step of crushing the heat-treated product obtained in the heat treatment step; A classification process including a first classification process for classifying the crushed material obtained in the crushing process into a coarse product and an intermediate product at a classification point of 0.6 mm or more and 2.4 mm or less, and a second classification process for classifying the intermediate product into a medium product and a fine product at a classification point of 40 μm or more and 300 μm or less; The present invention relates to a method for sorting valuable materials, the method comprising the steps of: <2> In the first classification step, the crushed product obtained in the crushing step is classified into a coarse product and an intermediate product at a classification point of 1.2 mm. <1> This is a method for sorting valuable materials described in the above. <3> In the heat treatment step, the lithium ion secondary battery is heat-treated at 660° C. or higher and 1,085° C. or lower. <1> from <2> 10. A method for sorting valuable materials according to any one of the preceding claims. <4> In the second classification step, the intermediate product is classified by a wet classification at a classification point of 40 μm or more and 75 μm or less. <1> from <3> 10. A method for sorting valuable materials according to any one of the preceding claims. <5> The lithium ion secondary battery is a lithium ion secondary battery pack selected from a lithium ion secondary battery pack for use in a vehicle, a lithium ion secondary battery pack for use in a power storage system, and a lithium ion secondary battery pack for use in an uninterruptible power supply. <1> from <4> 10. A method for sorting valuable materials according to any one of the preceding claims. Effect of the Invention

[0009] According to the present invention, it is possible to solve the various problems in the prior art, and to provide a method for separating valuable materials that can easily separate cobalt and nickel from iron and copper from a lithium ion secondary battery and obtain high-quality valuable materials with increased concentrations of cobalt and nickel at a high recovery rate. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram showing an example of a method for sorting valuable materials according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] (Method of sorting valuables) The method for separating valuable resources of the present invention includes a heat treatment step, a crushing step, and a classification step, and may further include other steps as necessary.

[0012] The method for separating valuable materials of the present invention is a method for recovering valuable materials from lithium ion batteries (LIBs). Here, the term "valuable materials" refers to materials that can be traded without being discarded, such as various metals such as cobalt (Co), nickel (Ni), iron (Fe), copper (Cu), and aluminum (Al).

[0013] As a result of extensive research, the present inventors have found that, in the conventional technology, when increasing (concentrating) the concentration of cobalt and nickel and recovering them from a target object such as a lithium ion secondary battery, the grade and recovery rate of each valuable material may be insufficient.

[0014] More specifically, when treating large LIB packs for in-vehicle use, energy storage systems (ESS) / uninterruptible power supplies (UPS), etc., which have become increasingly popular in recent years, the inventors have found that in the technology disclosed in Patent Document 1 (Patent No. 6748274), the proportion of the pack's exterior material (sometimes referred to as a "pack housing" and mainly made of iron) in the weight of the LIB pack is high, and when the LIB pack is crushed and classified, some of the crushed fine iron particles are also recovered in the fine product. The inventors have found that when wet magnetic separation is performed on this fine product containing iron, most of the iron in the crushed material is recovered as a magnetic substance, and the cobalt and nickel to be separated at this time are also magnetic and recovered as a magnetic substance, so that it is not possible to separate the cobalt and nickel from the iron. The inventors have also found that the non-magnetic substances in the wet magnetic separation contain a lot of sheet-like copper with a large diameter.

[0015] Furthermore, the technology disclosed in Patent Document 2 (Patent No. 6268130) proposes providing a sieving process prior to the magnetic separation process and separating copper using a 1.0 mm sieve. However, there is no mention at all of a method for removing iron that is magnetically attracted together with the cobalt and nickel and cannot be removed in the magnetic separation process.

[0016] Furthermore, in the technology disclosed in Patent Document 3 (Patent No. 6676124), when treating a large LIB pack for use in a vehicle, ESS / UPS, or the like, the volume of the LIB pack is large, and during heat treatment (aimed at deactivating the LIB and burning off the electrolyte), a difference in temperature occurs between the pack surface and the positive electrode active material (containing cobalt and nickel) contained in the cells inside the pack (the positive electrode active material is treated at a lower temperature than the pack surface), and the reduction of the cobalt and nickel oxides in the positive electrode active material to metal particles and particle growth do not proceed sufficiently compared to when a single cell is heat treated, and the inventors have found that it is difficult to recover the cobalt and nickel particles shown in Patent Document 3 into an intermediate product of 0.3 mm or more (in other words, in order to recover these fine cobalt and nickel particles, it is necessary to recover them into a fine particle product with a classification point of 300 μm or less).

[0017] As described above, the inventors have found that in the conventional techniques, when concentrating and recovering cobalt and nickel from a target material such as a lithium-ion secondary battery, there are problems in that impurities such as iron and copper cannot be sufficiently removed, and that the recovery rate of cobalt and nickel is low. Therefore, the inventors have conducted extensive research into a method for sorting valuables that can easily separate cobalt and nickel from iron and copper from a lithium ion secondary battery containing multiple types of valuables, and can obtain high-quality valuables with increased concentrations of cobalt and nickel at a high recovery rate, and have discovered the present invention. That is, the inventors have found that a method for sorting valuable materials, which includes a heat treatment step of heat-treating a lithium ion secondary battery containing valuable materials, a crushing step of crushing the heat-treated product obtained in the heat treatment step, and a classification step including a first classification step of classifying the crushed product obtained in the crushing step into a coarse product and an intermediate product at a classification point of 0.6 mm or more and 2.4 mm or less, and a second classification step of classifying the intermediate product into a medium product and a fine product at a classification point of 40 μm or more and 300 μm or less, can easily separate iron, copper, etc. from lithium ion secondary batteries containing multiple types of valuable materials, and can obtain valuable materials in which cobalt and nickel are concentrated at a high recovery rate.

[0018] <Heat treatment process> The heat treatment step is a step of heat treating a lithium ion secondary battery containing the valuable material. In the heat treatment step, for example, aluminum originating from the pack casing of the lithium ion secondary battery, from the constituent members of the module (sometimes referred to as a "module casing"), and from the cell case (sometimes referred to as a "cell casing") is separated as a molten material, and organic matter originating from the electrolyte is decomposed. More specifically, the heat treatment process is a process of heat treating the lithium ion secondary battery containing the valuables to melt aluminum, separating the molten material, and obtaining a heat-treated product (roasted product) remaining after separating the molten material. Here, the heat-treated product means a product obtained by heat treating the lithium ion secondary battery.

[0019] The method for carrying out the heat treatment in the heat treatment step is not particularly limited and may be appropriately selected depending on the purpose. For example, a method in which the lithium ion secondary battery is heated in a known roasting furnace may be mentioned.

[0020] The roasting furnace is not particularly limited and can be appropriately selected depending on the purpose. Examples of the roasting furnace include a rotary kiln, a fluidized bed furnace, a tunnel furnace, a batch furnace such as a muffle, a fixed bed furnace, a cupola, and a stoker furnace.

[0021] The atmosphere used for the heat treatment is not particularly limited and can be appropriately selected depending on the purpose. Examples of the atmosphere include air, an inert atmosphere, a reducing atmosphere, and a low-oxygen atmosphere. The atmospheric atmosphere (air atmosphere) means an atmosphere using atmospheric air (air) containing about 21% by volume of oxygen and about 78% by volume of nitrogen. The inert atmosphere can be, for example, an atmosphere consisting of nitrogen and / or argon. The reducing atmosphere means, for example, an atmosphere containing CO, H2, H2S, SO2, or the like in an inert atmosphere such as nitrogen or argon. By low oxygen atmosphere is meant an atmosphere containing 11% by volume or less of oxygen.

[0022] The conditions for heat treating (heating) the lithium ion secondary battery (heat treatment conditions) are not particularly limited as long as the conditions allow the individual components of the lithium ion secondary battery to be separated and made crushable in the crushing step described below, and can be appropriately selected depending on the purpose. Here, examples of the heat treatment conditions include the heat treatment temperature and the heat treatment time.

[0023] The heat treatment temperature means the temperature of the lithium ion secondary battery during the heat treatment. The heat treatment temperature is not particularly limited and can be appropriately selected depending on the form of the lithium ion secondary battery, etc., but is preferably a temperature equal to or higher than the melting point of the casing of the lithium ion secondary battery, or a temperature equal to or higher than the melting point of the positive electrode current collector and equal to or lower than the melting point of the negative electrode current collector of the lithium ion secondary battery.

[0024] When the heat treatment temperature is set to a temperature equal to or higher than the melting point of the casing of the lithium ion secondary battery, if the casing of the lithium ion secondary battery is formed of metal, the casing can be melted in the heat treatment process. For example, by placing a tray for collecting the molten metal of the casing under the lithium ion secondary battery, the metal originating from the casing and the electrodes of the lithium ion secondary battery, etc. can be easily separated and collected. More specifically, for example, when the casing of the lithium ion secondary battery contains aluminum, the heat treatment temperature is preferably set to 660°C or higher, which is the melting point of aluminum. By doing so, in the heat treatment step, the aluminum contained in the casing can be easily separated from other parts of the lithium ion secondary battery (e.g., electrodes, etc.), and the aluminum originating from the casing can be easily recovered. In addition, at this temperature, cobalt and nickel present as oxides in the positive electrode active material can be reduced to metal particles of cobalt and nickel by the action of carbon contained as the negative electrode active material.

[0025] When the heat treatment temperature is set to a temperature equal to or higher than the melting point of the positive electrode current collector and equal to or lower than the melting point of the negative electrode current collector, for example, in consideration of a typical configuration in which the positive electrode current collector is aluminum (melting point: 660°C) and the negative electrode current collector is copper (melting point: 1,085°C), the heat treatment temperature is preferably 660°C to 1,085°C, more preferably 660°C to 850°C. By doing so, the positive electrode current collector formed of aluminum foil melts and becomes embrittled, which makes it easier to break into fine particles in the crushing process described below, and the aluminum derived from the housing can be separated and recovered, while the copper contained in the negative electrode current collector can be kept in a shape close to that of foil without being melted. In addition, aluminum can be melted and separated while preventing embrittlement of metals other than aluminum.

[0026] The method for measuring the heat treatment temperature is not particularly limited and can be appropriately selected depending on the purpose. For example, a method for measuring the heat treatment temperature by inserting a thermometer such as a thermistor into the lithium ion secondary battery at the heat treatment temperature can be mentioned.

[0027] The heat treatment time means the time for which the lithium ion secondary battery is subjected to heat treatment. The heat treatment time is not particularly limited and can be appropriately selected according to the purpose, but is preferably 1 minute to 5 hours, more preferably 1 minute to 2 hours, and particularly preferably 1 minute to 1 hour. The heat treatment time may be, for example, the time until the lithium ion secondary battery reaches the heat treatment temperature, and the holding time may be short. The heat treatment time of 1 minute to 5 hours is advantageous in that the cost of the heat treatment can be suppressed and the efficiency of the heat treatment can be improved.

[0028] <<Lithium-ion secondary battery>> The lithium ion secondary battery is not particularly limited as long as it can be crushed at least after heat treatment, and can be appropriately selected from among known batteries. Specific examples of the lithium ion secondary battery include defective lithium ion secondary batteries generated during the manufacturing process of lithium ion secondary batteries, lithium ion secondary batteries discarded due to defects in the equipment used or the end of the life of the equipment used, used lithium ion secondary batteries discarded due to the end of the life, etc. These may be used alone or in combination of two or more types.

[0029] The shape, structure, size and material of the lithium ion secondary battery are not particularly limited and can be appropriately selected depending on the purpose. The shape of the lithium ion secondary battery cell is not particularly limited and can be appropriately selected depending on the purpose. Examples of the shape include laminate type, cylindrical type, button type, coin type, rectangular type, and flat type.

[0030] The form of the lithium ion secondary battery is not particularly limited and can be appropriately selected depending on the purpose. Examples of the form of the lithium ion secondary battery include a battery cell, a battery module, and a battery pack. The battery cell is a unit cell. The battery module refers to a plurality of battery cells connected together and assembled into one housing (module housing). The battery pack means a plurality of battery modules assembled in one housing (pack housing). The battery pack may also include a controller and a cooling device.

[0031] The lithium ion secondary battery may have a structure including, for example, a positive electrode, a negative electrode, a separator, an electrolyte, and an outer container, but may also have a state in which the positive electrode, the negative electrode, etc. are detached.

[0032] -Positive electrode- The positive electrode is not particularly limited as long as it has a positive electrode active material containing either one or both of cobalt and nickel, and can be appropriately selected depending on the purpose. The shape of the positive electrode is not particularly limited and may be appropriately selected depending on the purpose. For example, the shape may be a flat plate or a sheet.

[0033] --Positive electrode current collector-- The shape, structure, size, and material of the positive electrode current collector are not particularly limited and can be appropriately selected depending on the purpose. The positive electrode current collector may be in the form of, for example, a foil. Examples of the material for the positive electrode current collector include stainless steel, nickel, aluminum, copper, titanium, tantalum, etc. Among these, aluminum is preferable.

[0034] 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 substance and, if necessary, a conductive agent and a binder resin can be included. Examples of the positive electrode active material include lithium cobalt oxide (LiCoO2), lithium cobalt nickel oxide (LiCo 1 / 2 Ni 1 / 2 O2), NCM-based cathode material (LiNi x Co y Mn zO2 (x+y+z=1)), NCA-based positive electrode materials (nickel, cobalt, aluminum-based), lithium manganese oxide, and mixtures of these positive electrode materials. The conductive agent is not particularly limited and can be appropriately selected depending on the purpose. Examples of the conductive agent include carbon black, graphite, carbon fiber, and metal carbides. The binder resin is not particularly limited and can be appropriately selected depending on the purpose. Examples of the binder resin include homopolymers or copolymers of vinylidene fluoride, tetrafluoroethylene, acrylonitrile, ethylene oxide, and the like, and styrene-butadiene rubber.

[0035] -Negative electrode- The negative electrode is not particularly limited as long as it has a negative electrode active material containing carbon, and can be appropriately selected depending on the purpose. The shape of the negative electrode is not particularly limited and may be appropriately selected depending on the purpose. For example, the shape may be a flat plate or a sheet.

[0036] --Negative electrode current collector-- The shape, structure, size and material of the negative electrode current collector are not particularly limited and can be appropriately selected depending on the purpose. The negative electrode current collector may be in the form of, for example, a foil. Examples of the material for the negative electrode current collector include stainless steel, nickel, aluminum, copper, titanium, tantalum, etc. Among these, copper is preferable.

[0037] The negative electrode material is not particularly limited and can be appropriately selected depending on the purpose. Examples of the negative electrode material include carbon materials such as graphite and hard carbon, and titanates.

[0038] -Electrolyte- The electrolytic solution is not particularly limited and can be appropriately selected from known electrolytic solutions. For example, the electrolytic solution contains an electrolyte and an organic solvent, and further contains other components as necessary.

[0039] -Cell housing- The cell casing (sometimes referred to as "casing") is not particularly limited and can be appropriately selected depending on the purpose, but is preferably one that can accommodate the positive electrode, the negative electrode, the separator, the electrolyte, and the like, and examples thereof include a battery case. The material of the cell casing is not particularly limited and can be appropriately selected depending on the purpose. Examples of the material include aluminum and resin (plastic).

[0040] -Module housing- The module housing is not particularly limited and can be appropriately selected depending on the purpose, and examples of the module housing include those housing a plurality of battery cells. The material of the cell casing is not particularly limited and can be appropriately selected depending on the purpose. Examples of the material include aluminum and resin (plastic).

[0041] -Pack housing- The pack housing is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include a pack housing that houses a plurality of battery modules. The material of the cell casing is not particularly limited and can be appropriately selected depending on the purpose. Examples of the material include iron, stainless steel, aluminum, and resin (plastic).

[0042] <Crushing process> The crushing step is a step of crushing the heat-treated product obtained in the heat treatment step. The crushing step is not particularly limited as long as the heat-treated product can be crushed to obtain a crushed product, and can be appropriately selected depending on the purpose. Here, the crushed product means the product obtained by crushing the heat-treated product.

[0043] In the crushing step, the method for crushing the heat-treated product is not particularly limited and can be appropriately selected depending on the purpose, but a method in which the heat-treated product is crushed by impact to obtain crushed products is preferred. For example, when the casing of the lithium ion secondary battery is not melted in the heat treatment step, it is more preferred to pre-crush the heat-treated product by cutting it with a cutter before applying an impact to the heat-treated product.

[0044] Examples of the method for crushing the heat-treated product by impact include a method in which the heat-treated product is thrown by a rotating striking plate and struck against a collision plate to give an impact, and a method in which the heat-treated product is struck by a rotating striker (beater), and can be carried out, for example, by a hammer crusher. Another method for crushing the heat-treated product by impact includes a method in which the heat-treated product is struck by a ceramic ball, and this method can be carried out by a ball mill, and the like. The crushing of the heat-treated product by impact can also be carried out, for example, by using a biaxial crusher with a short blade width and blade length for crushing by compression. Furthermore, examples of the method for crushing the heat-treated product by impact include a method in which the heat-treated product is hit with two rotating chains to apply impact, and this can be carried out, for example, by a chain mill.

[0045] The crushing time in the crushing step is not particularly limited and can be appropriately selected depending on the purpose. For example, the crushing time per 1 kg of lithium ion secondary batteries is preferably from 1 second to 30 minutes, more preferably from 2 seconds to 10 minutes, and particularly preferably from 3 seconds to 5 minutes.

[0046] In addition, as for the crushing conditions in the crushing step, for example, when crushing with an impact / percussion type crusher such as a chain mill or a hammer mill, it is preferable to set the tip speed of the chain or hammer to 10 m / sec or more and 300 m / sec or less, and the residence time of the lithium ion secondary batteries in the crusher to 1 second or more and 10 minutes or less. By doing so, in the method for separating valuable materials, it is possible to crush the positive electrode material (e.g., copper, aluminum, etc.) and components derived from the casing, such as iron, without excessively crushing them.

[0047] <Classification process> The classification process includes a first classification process in which the crushed material obtained in the crushing process is classified into a coarse product and an intermediate product at a classification point of 0.6 mm or more and 2.4 mm or less, and a second classification process in which the intermediate product is classified into a medium product and a fine product at a classification point of 40 μm or more and 300 μm or less.

[0048] The classification step may include a further classification step such as a third classification step in addition to the first classification step and the second classification step, in which case the impurity grade of each product (each element of the valuable material) may be further reduced. An example of a mode in which a further classification step is performed is a mode in which additional classification is performed at a classification point below the second classification point after the second classification step (third classification step).

[0049] <<First classification process>> The first classification step is a step of classifying the crushed material obtained in the crushing step into a coarse product and an intermediate product at a classification point of 0.6 mm or more and 2.4 mm or less. By including the first step, the crushed material (intermediate product) from which at least one long piece of copper and iron has been removed in advance is treated in the second classification step, so that a fine product (valuable material) in which cobalt and nickel are more concentrated can be obtained. The first classification step may be repeated multiple times within the range of the classification point of the first classification step, thereby further reducing the impurity grade of each product (each element of valuable material).

[0050] The classification point in the first classification step is 0.6 mm or more and 2.4 mm or less, and from the viewpoint of further improving the accuracy of copper sorting, 1.2 mm is more preferable.

[0051] <<Second classification process>> The second classification step is a step of classifying the intermediate product obtained in the first classification step into a medium-grain product and a fine-grain product at a classification point of 40 μm or more and 300 μm or less. Here, the medium-sized product is a coarse-grained material obtained by classifying the intermediate product in the second classification step, and the fine-grained product is a fine-grained material obtained by classifying the intermediate product in the second classification step. The second classification step may be repeated multiple times within the range of the classification point of the second classification step, thereby further reducing the impurity grade of each product (each element of valuable material). Moreover, the second classification step more preferably includes wet classification at least once. Wet classification allows classification while suppressing particle aggregation compared to dry classification, and can further reduce the impurity quality of each product.

[0052] The classification step is not particularly limited as long as it is a processing method that can classify the crushed material within the range of the classification point, and can be appropriately selected depending on the purpose. For example, a multi-stage vibrating sieve, a cyclone, a cyclosizer, a JIS Z8801 standard sieve, etc. can be used.

[0053] Here, the "classification point" refers to the sieve opening in the case of sieving, and the 50% separation diameter in the case of flow classification. In this specification, the "50% separation diameter" refers to the particle size at which the distribution rate to the cyclone underflow for a certain classification particle size is 50%. For example, a cyclone with a classification point of 10 μm refers to a cyclone and its operating conditions that can recover 50% of 10 μm particles in the underflow.

[0054] <Other processes> The method for separating valuable resources may include other steps in addition to the heat treatment step, the crushing step, and the classification step. The other steps are not particularly limited and can be appropriately selected depending on the purpose.

[0055] <Example of embodiment> Here, an example of an embodiment of the method for sorting lithium ion secondary batteries of the present invention will be described with reference to the drawings. Fig. 1 is a diagram showing an example of a process flow in an embodiment of the method for sorting valuable materials of the present invention.

[0056] 1, in this embodiment, first, a lithium ion secondary battery is heat-treated to obtain a heat-treated lithium ion secondary battery. At this time, the lithium ion secondary battery is heat-treated at a temperature equal to or higher than the melting point of aluminum and lower than the melting point of copper (660°C or higher and 1,085°C or lower), and the aluminum contained in the lithium ion secondary battery is melted, separated, and recovered (molten aluminum is obtained). Next, the heat-treated lithium-ion secondary batteries are crushed to obtain crushed material, which is then classified (first classification process) using a sieve with mesh sizes of 0.6 mm to 2.4 mm into a coarse product (material that passes the sieve; most of the copper and iron are removed) and an intermediate product (material that passes the sieve; cobalt and nickel are recovered). Next, the intermediate product is classified at a classification point of 40 μm to 300 μm, and is classified into a medium-grain product (coarse material) and a fine-grain product (fine material) (second classification process). Here, some of the copper (Cu) and iron (Fe) recovered in the intermediate product in the first classification process can be separated into the medium-grain product, and a fine-grain product with low copper and iron content and high cobalt and nickel content can be recovered. In this manner, in the present embodiment, the cobalt, nickel, and manganese contained in the lithium ion secondary battery, and the iron and copper can be separated efficiently with high accuracy, and high-quality valuable materials with increased concentrations of cobalt and nickel can be obtained at a high recovery rate. EXAMPLES

[0057] The present invention will be specifically described below by way of examples, but the present invention is not limited to these examples in any way.

[0058] Example 1 <Heat treatment process> A lithium-ion secondary battery battery pack (approximately 75 kg) containing an iron member in the pack housing and aluminum in the cell housing was heat-treated at a heat treatment temperature of 800°C (heated over 1 hour and then held for 2 hours) using a batch-type burner furnace manufactured by Ecosystem Akita Co., Ltd. as the heat treatment device to obtain a heat-treated product. When carrying out the heat treatment, the lithium-ion secondary battery was placed on a container and placed in the heat treatment device, and the aluminum was melted and separated and collected at the bottom of the container (aluminum was melted and collected).

[0059] <Crushing process> Next, the heat-treated product (heat-treated lithium ion secondary batteries) obtained in the heat treatment process was crushed using a hammer crusher (Makino-type swing hammer crusher HC-20-3.7, manufactured by Makino Sangyo Co., Ltd.) as a crushing device under conditions of 50 Hz (hammer peripheral speed 38 m / sec) and a screen at the outlet with a grate-type opening of 30 mm x 200 mm, to obtain crushed lithium ion secondary batteries.

[0060] <First classification process> Next, the crushed lithium-ion secondary battery material was sieved (first classification process) using a sieve (diameter 200 mm, manufactured by Tokyo Screen Co., Ltd.) with mesh openings of 1.2 mm, and separated into over-sieve material (coarse product) and under-sieve material (intermediate product), and 1 kg of the under-sieve product (intermediate product) was used as the crushed material for the next process.

[0061] -Quality analysis- A portion of the undersize product (intermediate product) obtained in the first classification process was collected, dissolved in aqua regia, and analyzed using an ICP atomic emission spectrometer (ICP-AES, iCAP6300, manufactured by Thermo Fisher Scientific Inc.) to determine the purity (mass%) of each element contained in the undersize product (intermediate product), which is shown in Table 1.

[0062] [Table 1]

[0063] <Second classification process> The undersize product (intermediate product) obtained in the above-mentioned "first classification step" was treated as the object of the second classification step. The mixture was classified into an oversize product (medium-grain product) and an undersize product (fine-grain product) using a 300 μm electromagnetic sieve. The electromagnetic sieve was operated for 20 minutes at an amplitude of 1.45 mm using an electromagnetic sieve shaker (AS200 Control, manufactured by Recche).

[0064] -Quality analysis- Using a method similar to that used for the quality analysis of the intermediate product in the first classification process, the content of each element in the undersize product (fine product) obtained in the second classification process was determined, and the recovery rate (%) of each element in the undersize product (fine product) obtained in the second classification process was determined when the amount of each element in the intermediate product obtained in the first classification process was set to 100%, and is shown in Table 2.

[0065] Example 2 In Example 1, except that the classification point in the second classification step was changed to 150 μm, the <heat treatment step>, <crushing step>, <first classification step>, and <second classification step> were performed in the same manner as in Example 1, and a fine product was recovered. In addition, the recovery rate of each element in this fine product was determined in the same manner as in Example 1, and the results are shown in Table 2.

[0066] Example 3 In Example 1, except that the classification point in the second classification step was changed to 75 μm, the <heat treatment step>, <crushing step>, <first classification step>, and <second classification step> were performed in the same manner as in Example 1, and a fine product was recovered. In addition, the recovery rate of each element in this fine product was determined in the same manner as in Example 1, and the results are shown in Table 2.

[0067] Example 4 In Example 1, except that the classification point in the second classification step was changed to 40 μm, the <heat treatment step>, <crushing step>, <first classification step>, and <second classification step> were performed in the same manner as in Example 1, and a fine product was recovered. In addition, the recovery rate of each element in this fine product was determined in the same manner as in Example 1, and the results are shown in Table 2.

[0068] Example 5 In Example 1, except that the second classification step was changed as follows, the heat treatment step, crushing step, and first classification step were performed in the same manner as in Example 1, and a fine product was recovered. The recovery rate of each element in the fine product was determined in the same manner as in Example 1, and is shown in Table 2.

[0069] <Second classification process> 0.1 kg of the intermediate product obtained in the above-mentioned <First Classification Step> was added to 0.5 L of water in a 1 L glass beaker, and then the mixture was stirred with a magnetic stirrer at 300 rpm for 1 hour to prepare a slurry of the intermediate product. This slurry was classified into a sieve-over product (medium-sized product) and an under-sieve product (slurry containing fine-sized product) using a 40 μm electromagnetic sieve (electromagnetic sieve shaker, AS200 Control, manufactured by Recce) operated at an amplitude of 1.45 mm for 20 minutes, and the slurry containing the fine-sized product was collected. The slurry containing the obtained fine-sized product was subjected to solid-liquid separation using 5C filter paper, and the cake was dried at 105 ° C for 2 hours to obtain a fine-sized product.

[0070] Comparative Example 1 In Example 1, except that the classification point of the second classification step was changed to 600 μm, the <heat treatment step>, <crushing step>, <first classification step>, and <second classification step> were performed in the same manner as in Example 1, and a fine product was recovered. In addition, the recovery rate of each element in this fine product was determined in the same manner as in Example 1, and the results are shown in Table 2.

[0071] [Table 2]

[0072] From the results in Table 2, it was possible to achieve the enrichment of cobalt and nickel as a fine product in Examples 1 to 5. In other words, cobalt and nickel were obtained in the fine product at a recovery rate of 70% or more, and 70% or more of the iron and 50% or more of the copper contained in the intermediate product were removed from the fine product. In Comparative Example 1, more than 60% of the iron and more than 80% of the copper were recovered in the fine product and could not be sufficiently separated from the cobalt and nickel.

Claims

1. A heat treatment step of heat treating a lithium ion secondary battery containing valuable materials; A crushing step of crushing the heat-treated product obtained in the heat treatment step; A classification process including a first classification process for classifying the crushed product obtained in the crushing process into a coarse product and an intermediate product at a classification point of 0.6 mm or more and 2.4 mm or less, and a second classification process for classifying the intermediate product into a medium product and a fine product at a classification point of 40 μm or more and 300 μm or less; Including, A method for separating valuable materials, characterized in that in the second classification step, cobalt and nickel are recovered in the fine product.

2. 2. The method for separating valuable resources according to claim 1, wherein in the first classification step, the crushed material obtained in the crushing step is classified into the coarse product and the intermediate product at a classification point of 1.2 mm.

3. The method for separating valuable resources according to claim 1 or 2, wherein in the heat treatment step, the lithium ion secondary battery is heat treated at 660° C. or higher and 1,085° C. or lower.

4. 4. The method for separating valuable resources according to claim 1, wherein in the second classification step, the intermediate product is classified by a wet method.

5. A method for sorting valuable materials described in any of claims 1 to 4, wherein in the second classification step, the intermediate product is wet classified at a classification point of 40 μm or more and 75 μm or less.

6. A method for sorting valuable materials described in any one of claims 1 to 5, wherein at least one of copper and iron is separated into the medium-grain product in the second classification process.

7. A method for sorting valuables described in any one of claims 1 to 6, wherein the lithium ion secondary battery is a lithium ion secondary battery pack selected from those for use in vehicles, power storage systems, and uninterruptible power supplies.

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