JP2021139020A - Valuable metal recovery method from waste battery - Google Patents

Abstract

To provide a method capable of efficiently and stably recovering a valuable metal contained in waste batteries, while efficiently removing the impurity.SOLUTION: The method of recovering the valuable metal from the waste battery according to the present invention may comprise a roasting step S11 for roasting waste batteries, a crushing step S12 for crushing the roasted material, a magnetic separation process S13 for separating the crushed material into a magnetized material and a nonmagnetic material by applying a magnetic selection treatment to the crushed material, and a sieve separation step S14 for separating the non-magnetized material into an oversize and an undersize. Furthermore, the valuable metal recovery method from the waste batteries according to the present invention comprises a roasting step S21 for roasting the waste batteries, a crushing step S22 for crushing the roasted material, a sieve separation step S23 for sieve separating the crushed material into an oversize and an undersize, and a magnetic selection step S24 for separating a magnetized material and a non-magnetized material by applying a magnetic selection treatment to the undersize. Herein, in the magnetic selection step S13, S24, a suspension type magnetic selection machine is preferably used to treat.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method for recovering valuable metals contained in a waste battery.

In recent years, lithium-ion batteries have become widespread as secondary batteries that are lightweight and can obtain high output. As a basic structure of a lithium ion battery, there are a negative electrode current collector made of copper foil and a positive electrode current collector made of aluminum foil inside an outer can made of metal such as aluminum or iron.

A negative electrode active material such as graphite is fixed to the surface of the negative electrode current collector to form a negative electrode material. Further, a positive electrode active material such as lithium nickel oxide or lithium cobalt oxide is fixed to the surface of the positive electrode current collector to form a positive electrode material. The negative electrode material and the positive electrode material are charged into the above-mentioned outer can through a separator made of a polypropylene porous resin film or the like, and an electrolyte such as _{lithium hexafluorophosphate (LiPF 6) is contained in the gap between the negative electrode material and the positive electrode material.} An electrolytic solution or the like is sealed.

Lithium-ion batteries are currently being used as in-vehicle batteries for hybrid vehicles, electric vehicles, and the like. However, the lithium-ion battery mounted on an automobile gradually deteriorates as it is used repeatedly, and finally reaches the end of its life and is discarded.

As the power of automobiles changes from gasoline to electricity, the number of batteries used for automobiles will increase, and at the same time, the number of batteries that will be discarded will also increase.

Attempts and specific proposals for reusing such discarded lithium-ion batteries and defective products (hereinafter collectively referred to as "waste batteries") generated during the manufacture of lithium-ion batteries as resources have been conventionally made. Many are done. Most of them are pyrometallurgical processes in which waste lithium-ion batteries are put into a high-temperature furnace to melt the entire amount.

Here, in addition to commercially valuable elements such as nickel, cobalt, and copper (hereinafter, these are referred to as "valuable metals"), waste batteries include carbon, aluminum, fluorine, phosphorus, and the like. Contains elements that are not commercially recoverable (hereinafter collectively referred to as "impurities"). When recovering valuable metals from waste batteries, it is necessary to efficiently separate the above-mentioned impurities from the valuable metals.

For this reason, for example, a waste battery is roasted to perform a detoxification treatment for removing fluorine, phosphorus, etc., then crushed or crushed, and then separated using a sieve or a magnetic separator, and the separated product is described above. It is valuable to use the dry smelting process (hereinafter, also simply referred to as “dry treatment”) and the wet smelting process (hereinafter, also simply referred to as “wet treatment”) in which separation is performed using a liquid such as an acid or an organic solvent. A method of recovering metal has been carried out.

As a method for recovering cobalt, which is a valuable metal from a waste battery by a dry treatment, for example, Patent Document 1 proposes a process in which a waste lithium ion battery is put into a melting furnace and oxygen is blown into it to oxidize it.

Further, Patent Document 2 proposes a process in which a waste lithium ion battery is melted, slag is separated to recover valuable resources, and then a lime-based solvent (flux) is added to remove phosphorus.

Further, in Patent Document 3, as a method of recycling a battery pack having a resin component including an assembled battery formed by connecting a plurality of cells in series and a control unit for controlling the assembled battery, a charged assembled battery It has a step of roasting the battery pack containing the battery pack as it is and a complete burning step of completely burning the unburned thermal decomposition gas generated at the time of roasting the battery pack. Disclosed is a recycling method in which the assembled battery in the battery pack is roasted in a non-oxidizing atmosphere or a reducing atmosphere at a temperature equal to or higher than the carbonization temperature of the resin forming the resin part and lower than the melting point of the metal part of the battery pack. There is.

However, these methods have a problem that they require a great deal of cost for dehydration and drying treatments, as well as for the main body of the apparatus and maintenance.

In addition, since waste batteries contain a large amount of impurities such as iron, it is indispensable to eliminate impurities as much as possible in order to efficiently recover valuable metals. However, impurities and valuable metals are often mixed in various forms, and it is economically efficient, and it has not been easy to separate and recover valuable metals reliably and stably.

Japanese Unexamined Patent Publication No. 2013-091826 Japanese Patent Application Laid-Open No. 2013-506048 Japanese Unexamined Patent Publication No. 2010-3512

The present invention has been proposed in view of such circumstances, and provides a method capable of efficiently and stably recovering valuable metals contained in a waste battery while effectively removing impurities. The purpose is to provide.

The present inventor has made extensive studies to solve the above-mentioned problems. As a result, the roasted product obtained by roasting the waste battery is crushed to a predetermined size, and then the crushed product is subjected to a magnetic separation treatment, and the magnetically separated non-magnetized material is sieved and sieved. It was found that valuable metals can be recovered efficiently and stably by recovering vulgarities. Alternatively, it has been found that the same effect can be obtained by subjecting the sieving material obtained by sieving the crushed material to a magnetic separation treatment and recovering the magnetically separated non-magnetized material. That is, the present invention provides the following.

(1) The first invention of the present invention includes a roasting step of roasting a waste battery, a crushing step of crushing a roasted product, and a magnetized and non-magnetized material obtained by subjecting the crushed material to a magnetic separation process. This is a method for recovering valuable metals from a waste battery, which comprises a magnetic separation step of dividing into

(2) A second invention of the present invention is a method for recovering valuable metals from a waste battery, wherein in the magnetic separation step, the crushed material is subjected to a magnetic separation treatment using a suspension type magnetic separator in the first invention. Is.

(3) In the third invention of the present invention, in the second invention, in the magnetic separation step, the size of the crushed material is adjusted to be less than or equal to a predetermined value, and the crushed material adjusted in size is subjected to the magnetic separation treatment. This is a method of recovering valuable metals from waste batteries.

(4) In the third invention, the fourth invention of the present invention is the upper space of the belt conveyor among the crushed materials which are placed on the belt conveyor and conveyed through the crushing step in the magnetic separation step. This is a method for recovering valuable metals from a waste battery by subjecting the crushed material adjusted to a certain size or less in the height direction by the baffle plate installed in the above.

(5) In the fifth invention of the present invention, in the third or fourth invention, in the magnetic separation step, the crushed material was adjusted in height to a range of 20 mm or more and 120 mm or less, and the size was adjusted. This is a method for recovering valuable metals from a waste battery by subjecting the crushed material to the magnetic separation treatment.

(6) In the sixth invention of the present invention, in any one of the first to fifth inventions, an oxidative roasting step of oxidatively roasting the sieved product and a reduction melting of the oxidative roasted product to form a slag. This is a method for recovering valuable metals from waste batteries, further comprising a reduction melting step of obtaining an alloy containing valuable metals.

(7) In the seventh invention of the present invention, in any one of the first to sixth inventions, the valuable metal contains at least one selected from the group consisting of cobalt, nickel, and copper. This is a method for recovering valuable metals from batteries.

(8) The eighth invention of the present invention is a roasting step of roasting a waste battery, a crushing step of crushing a roasted product, and sieving the crushed product to separate a sieving product and a sieving product. This is a method for recovering valuable metals from a waste battery, which comprises a sieving step and a magnetic separation step of subjecting the sieved material to a magnetized material and a non-magnetized material.

(9) In the eighth invention, the ninth invention of the present invention contains an oxidative roasting step of oxidatively roasting the non-magnetized material and a slag and a valuable metal by reducing and melting the oxidative roasted material. This is a method for recovering valuable metals from a waste battery, further comprising a reduction melting step of obtaining an alloy to be produced.

According to the present invention, valuable metals contained in waste batteries can be efficiently and stably recovered.

It is a process drawing which shows an example of the flow of a valuable metal recovery method. It is a figure for demonstrating the suspension type magnetic separator provided in the upper part of the predetermined part of the transport path of a belt conveyor. An obstruction plate is installed in the upper space of a predetermined location (upstream from the hanging magnetic separator) on the conveyor belt, and the crushed material to be transported that is smaller than a certain size in the height direction is passed through. It is the figure which showed typically the flow which feeds to a magnetic separator. It is a process drawing which shows another example of the flow of a valuable metal recovery method.

Hereinafter, a specific embodiment of the present invention (hereinafter, referred to as “the present embodiment”) will be described in detail. The present invention is not limited to the following embodiments, and various modifications can be made without changing the gist of the present invention.

≪1. Overview of valuable metal recovery method ≫
The method for recovering valuable metal according to the present embodiment is a method for recovering valuable metal from a waste battery. Generally, when recovering a valuable metal from a waste battery, a wet treatment may be performed in addition to the dry treatment, but the valuable metal recovery method according to the present embodiment is mainly related to the dry treatment.

Specifically, in this valuable metal recovery method, a roasted product obtained by roasting a waste battery for detoxification is crushed to a predetermined size, and then the crushed product is subjected to a magnetic separation process to magnetize the crushed product. It is divided into a non-magnetized material and a non-magnetized material, and then the non-magnetized material is sieved by a sieve having a predetermined opening to separate a superficial material and a non-magnetized material. After that, the separated sieve products are oxidatively roasted, and the oxidative roasted products are reduced and melted to obtain an alloy containing slag and a valuable metal.

Further, as another embodiment of the valuable metal recovery method, a roasted product obtained by roasting a waste battery for detoxification is crushed to a predetermined size, and then the crushed product is sieved with a predetermined opening. It is separated by sieving and separated into a sieving product and a sieving product, and then the separated sieving product is subjected to a magnetic separation treatment to separate a magnetized product and a non-magnetized product. After that, the classified non-magnetized material is oxidatively roasted, and the oxidatively roasted material is reduced and melted to obtain an alloy containing slag and a valuable metal.

According to these methods, the crushed material is contained in the waste battery by subjecting the crushed material to a magnetic separation treatment, or by performing a magnetic separation treatment on the sieved product obtained by sieving the crushed material. The metal component of impurities, mainly iron, can be effectively removed. As described above, since iron can be effectively removed, the melting point and viscosity of the slag can be easily designed when the slag is reduced and melted in the subsequent process, and the valuable metal can be efficiently recovered. Further, the treatment for removing impurities such as iron is not required in the post-process, and the treatment cost can be reduced.

Here, as described above, the waste battery is a defective product generated in the manufacturing process of a secondary battery such as a used lithium ion battery, a positive electrode material constituting the secondary battery, and a residue inside the manufacturing process. , A concept that includes waste materials in the manufacturing process of lithium-ion batteries such as generated waste. As described above, such waste batteries contain valuable metals such as nickel, cobalt, and copper that have economic value to be recovered and reused.

≪2. About each process of valuable metal recovery method ≫
<2-1. First Embodiment>
FIG. 1 is a process diagram showing an example of the flow of the valuable metal recovery method according to the present embodiment. This valuable metal recovery method is divided into a roasting step S11 for roasting a waste battery, a crushing step S12 for crushing a roasted product, and a magnetized material and a non-magnetized material by subjecting the crushed material to a magnetic separation treatment. It has a magnetic separation step S13, and a sieving step S14 in which the magnetically selected non-magnetized material is subjected to a sieving treatment to separate a lumpy product to be a sieving product and a powder to be a sieving product. Here, valuable metals such as nickel and cobalt are metals contained in the positive electrode active material, and are recovered in powder form in a state of being separated from impurities such as iron through these steps. Therefore, a large amount of valuable metal is distributed in the sieve.

Further, an oxidative roasting step S15 in which the obtained sieve product is oxidatively roasted, and a reduction melting step S16 in which the slag and an alloy (metal) containing a valuable metal are obtained by reducing and melting the oxidative roasted product. Further has.

The valuable metal alloy obtained through such a series of dry treatments is subjected to wet treatments such as neutralization treatment, solvent extraction treatment, and electrowinning to remove impurity components remaining in the alloy. Valuable metals can be further refined and recovered as high value-added metals.

[Roasting process]
The main purpose of the roasting step S11 is to remove the fluorine component, which is an electrolytic solution component contained in the waste battery, to make it harmless, and to facilitate crushing in the next step.

The conditions for the roasting treatment are not particularly limited, but the roasting temperature is heated to 700 ° C. or higher from the viewpoint of ensuring detoxification and making the waste battery brittle and facilitating crushing in the next step. Is preferable. The upper limit of the roasting temperature is not particularly limited, but is preferably 1200 ° C. or lower. If the roasting temperature is too high, a part of iron, etc., which is mainly used for the outer shell of the waste battery, adheres to the inner wall of the roasting furnace body such as a kiln, which hinders smooth operation. Or, it may lead to deterioration of the kiln itself, which is not preferable.

Further, if the waste batteries used for the roasting process are stacked too much in the furnace, the inside cannot be sufficiently roasted and uneven roasting occurs. Therefore, from the viewpoint of enabling uniform roasting, it is preferable to select the processing amount, the heating capacity of the roasting furnace, and the like. For example, it is preferable to perform a preliminary test in advance to determine the optimum temperature and roasting time.

The heating method at the time of roasting is not particularly limited, and may be an electric type or a burner type using a fuel such as oil or gas. In particular, burner-type heating is preferable because of its low cost.

[Crushing process]
In the crushing step S12, the roasted product obtained by roasting the waste battery in the roasting step S11 is crushed and finely separated.

The crushing device used in the crushing treatment is not particularly limited, and for example, a rod mill, a jaw crusher, a twin-screw kneader, a chain mill, or the like can be used.

[Magnetic separation process]
In the magnetic separation step S13, the crushed material obtained by crushing the roasted material in the crushing step S12 is subjected to a magnetic separation treatment to classify the crushed material into a magnetized material and a non-magnetized material. The treatment in the magnetic selection step S13 is to separate and remove an impurity contained in the waste battery, a metal mainly composed of iron, as a magnetized substance.

Here, if the recovered valuable metal contains an impurity iron, the design of the melting point, viscosity, etc. of the slag becomes complicated during the pyrometallurgy in the reduction melting step S16 in the subsequent step. Further, if iron cannot be sufficiently removed from the recovered valuable metal, a separate treatment for removing iron is required in a subsequent process, and the treatment cost increases.

In this regard, according to the valuable metal recovery method according to the present embodiment, the magnetic separation step S13 is provided, the crushed material is subjected to the magnetic separation treatment, and the classified non-magnetized material is supplied to the next step to supply the valuable metal. I am trying to collect it. From this, the impurity metal component such as iron classified as a magnetized substance can be effectively removed. In addition, since iron can be prevented from being contained in the valuable metal to be recovered, the design of the reduction melting treatment in the subsequent process becomes easy, the treatment for removing iron becomes unnecessary, and the increase in the treatment cost is suppressed. be able to.

The method of magnetic separation processing is not particularly limited, but can be performed by, for example, a method using a hanging magnetic separator. FIG. 2 is a diagram for explaining a suspension type magnetic separator provided above a predetermined portion of a conveyor belt transport path.

As shown in FIG. 2, the suspension type magnetic separator 12 is configured such that a magnet 20 is suspended above the transport path of the belt conveyor 11, and a magnet 20 is suspended around the magnet for discharging a magnetized material. The belt conveyor 13 of the above is attached so as to wrap around the magnet 20. In the belt conveyor 11, the transport direction is from the front side of the paper surface to the back side of the paper surface, and the suspension type magnetic separator 12 is installed at the upper part in the middle of the path in the transport direction.

As shown in FIG. 2, the crushed material 1 obtained through the crushing step S2 is transported by the belt conveyor 11 to the processing in the next process, and is suspended above a predetermined portion of the transport path. By the lowering type magnetic separator 12, impurities such as iron in the crushed material 1 are magnetized on the magnet 20 to become the magnetized material 1A, and the crushed material containing valuable metal is not magnetized on the magnet 20 and is a non-magnetized material. Each is classified as 1B.

By performing the magnetic separation process using the hanging magnetic separator 12 in this way, the magnetized material 1A such as iron attracted to the magnet 20 is kept away from the periphery of the magnet 20 by the magnetized material discharge belt conveyor 13. Therefore, it is possible to more reliably and efficiently separate valuable metals from impurity metal components such as iron.

Here, in the magnetic separation process using a hanging magnetic separator, in addition to the magnetic force of the magnet, the distance between the magnet and the crushed material in the height direction determines the removal rate of impurities such as iron and the separation of valuable metals and impurities. It has a great influence on the rate. For example, when processing a large amount of waste batteries, some of them are inevitably insufficiently roasted or crushed, and large lumps are subjected to a magnetic separator. At this time, in the conventional general magnetic separation treatment, valuable metals and impurities such as iron cannot be sufficiently and effectively separated from the coarse crushed material, and stable treatment cannot be performed. Therefore, valuable metals are often distributed to the magnetized material together with the can body made of iron or the like.

Therefore, in this valuable metal recovery method, in the processing in the magnetic separation step S13, the size of the crushed material is adjusted to be small and equal to or less than a predetermined value, and the crushed material whose size has been adjusted is subjected to magnetic separation processing using a magnetic separator. Is preferable. It is also preferable that the amount of crushed material supplied to the magnetic separator is constant.

As a method of adjusting the size of the crushed material, for example, as shown in the schematic diagram of FIG. 3, the upper part of the position before the crushed material 1 conveyed by the belt conveyor 11 enters the magnet 20 portion of the suspension type magnetic separator 12. In the space, a baffle plate 30 whose height is adjusted from the belt conveyor 11 is installed, and an obstacle plate 30 having a certain size or less in the height direction is passed through and supplied to the hanging magnetic separator 12. According to such a method, the crushed material 1 that has passed through the baffle plate 30 becomes a crushed material 1D adjusted to a size equal to or less than the installation height of the baffle plate 30 (height of the lower end portion 30a), and the size is adjusted. Only the crushed material 1D is supplied to the suspension type magnetic separator 12 (conveyed below the suspension type magnetic separator 12), and the magnetic separation process is performed.

On the other hand, the coarse crushed material 1E exceeding a certain size in the height direction is collected by the obstruction plate 30 provided on the belt conveyor 11 because the transportation is obstructed, and is not supplied to the suspension type magnetic separator 12. Become. The coarse crushed material 1E removed by the baffle plate 30 can be crushed again and subjected to magnetic separation treatment to efficiently remove impurities such as iron and reduce the recovery loss of valuable metals.

Specifically, the size of the crushed material to be adjusted (size in the height direction) is not particularly limited, but is preferably in the range of about 20 mm or more and 120 mm or less. By performing magnetic separation treatment on the crushed material adjusted to such a size, it is possible to more reliably magnetize and remove the impurity metal component such as iron as a magnetized material on the magnet of the magnetic separator, which is more effective and valuable. Can be separated from metal.

The size in the height direction of the crushed material is a concept that includes not only the size of a single particle of the crushed material but also the size of the loading height of the crushed material loaded on the belt conveyor.

[Sieve separation process]
In the sieving step S14, the non-magnetized material that has been magnetically separated and classified in the magnetic separation step S13 is separated into a sieving product and a sieving product using a sieve (sieving machine) having a predetermined opening. .. Especially in the case of a waste battery, the positive electrode active material containing a large amount of valuable metal is crushed into powder and distributed under a sieve. Therefore, the valuable metal can be efficiently recovered by separating the sieving product and the sieving product by sieving.

In the valuable metal recovery method according to the present embodiment, the non-magnetized material from which the impurity metal component such as iron has been removed by the magnetic separation process in the magnetic separation step S13 of the previous step is targeted for the sieving process. The recovered sieve product contains a valuable metal in which the content of impurities is suppressed.

The sieving process is not particularly limited and can be performed using a commercially available sieving machine. Further, the mesh opening of the sieve (opening of the screen) and the like can be appropriately set based on the conditions for separating the upper and lower sieve products. If the mesh size of the sieve is too large, a large amount of non-valuable metal as well as valuable metal may be recovered under the sieve, which is not preferable. Further, if the mesh size of the sieve is too small, a large amount of valuable metal may be contained on the sieve, which is not preferable. For example, when the mesh size of the sieve is 5 mm or less, valuable metals can be efficiently recovered, which is preferable.

It is preferable that the sieving machine is placed in a closed space so that the crushed material does not scatter around. By making it possible to supply the crushed material to the sieving machine in a sealed state in this way, it is possible to more efficiently prevent the scattering of the powdery material and the accompanying loss of recovery of valuable metals, and also in terms of safety and work. It is also preferable from the environmental point of view.

[Oxidation roasting process]
Next, in the oxidative roasting step S15, the sieved product obtained in the sieving step S14 is roasted in an oxidizing atmosphere. By the roasting treatment in the oxidative roasting step S15, the carbon component (carbon) contained in the sieve can be oxidized and removed. Specifically, the carbon content in the obtained oxidized roasted product is set to approximately 0% by mass.

In this way, carbon can be removed by roasting in an oxidizing atmosphere, and as a result, the molten fine particles of the reduced valuable metal locally generated in the reduction melting step S16 of the next step are physically damaged by carbon. It is possible to agglomerate without any, and it can be recovered as an integrated alloy. Further, in the reduction melting step S16, it is possible to suppress the reduction of phosphorus contained in the contents of the battery by carbon, effectively oxidatively remove the phosphorus, and suppress the distribution in the alloy of the valuable metal.

In the oxidative roasting step S15, oxidative roasting is performed at, for example, a temperature of 600 ° C. or higher (oxidative roasting temperature). By setting the roasting temperature to 600 ° C. or higher, carbon contained in the battery can be effectively oxidized and removed. Further, the processing time can be shortened by preferably setting the temperature to 700 ° C. or higher. Further, the upper limit of the oxidative roasting temperature is preferably 900 ° C. or lower, whereby the thermal energy cost can be suppressed and the processing efficiency can be improved.

The oxidative roasting process can be performed using a known roasting furnace. Further, it is preferable to provide a furnace (preliminary furnace) different from the melting furnace used in the melting process in the reduction melting step S16 of the next step, and perform the process in the preliminary furnace. As the roasting furnace, any type of kiln capable of performing an oxidation treatment (roasting) inside the crushed material by heating the crushed material while supplying oxygen can be used. As an example, a known rotary kiln, tunnel kiln (Haas furnace) or the like can be preferably used.

[Reduction melting process]
In the reduction melting step S16, the oxidative roasted product obtained by the roasting treatment in the oxidation roasting step S15 is reduced and melted to obtain a slag containing impurities and an alloy (metal) containing a valuable metal. In the reduction and melting step S16, the oxide of the impurity element obtained by oxidation in the oxidation roasting treatment remains as it is, and the oxide of the valuable metal that has been oxidized in the oxidation roasting treatment is reduced and melted. As a result, an alloy that is separated from the impurities and the reduced product is integrated can be obtained. The alloy obtained as a melt is also referred to as "fused gold".

In the reduction melting step S16, for example, the treatment can be performed in the presence of carbon. The carbon is a reducing agent capable of easily reducing the valuable metals such as nickel and cobalt to be recovered. For example, 1 mol of carbon can reduce 2 mol of an oxide of a valuable metal such as nickel oxide. Examples include graphite. Further, a hydrocarbon or the like capable of reducing 2 mol to 4 mol per 1 mol of carbon can also be used as a carbon supply source. As described above, by reducing and melting in the presence of carbon as a reducing agent, the valuable metal can be efficiently reduced and an alloy containing the valuable metal can be effectively obtained.

As carbon, in addition to artificial graphite and natural graphite, coal, coke and the like can be used as long as impurities are acceptable in the product and post-processes. Further, in the reduction melting treatment, it is desirable to appropriately adjust the abundance of carbon. Specifically, preferably, the ratio is more than 7.5% by mass and 10% by mass or less with respect to 100% by mass of the oxidized roasted product to be treated, and more preferably 8.0% by mass or more and 9.0% by mass or less. Melts in the presence of a proportion of carbon.

The temperature condition (melting temperature) in the reduction melting treatment is not particularly limited, but is preferably in the range of 1320 ° C. or higher and 1600 ° C. or lower, and more preferably in the range of 1450 ° C. or higher and 1550 ° C. or lower. Further, in the reduction melting treatment, an oxide-based flux may be added and used. In the reduction melting treatment, dust, exhaust gas, etc. may be generated, but it can be detoxified by performing a conventionally known exhaust gas treatment.

<2-2. Second embodiment>
FIG. 4 is a process diagram showing an example of the flow of the valuable metal recovery method according to another embodiment. This valuable metal recovery method includes a roasting step S21 for roasting a waste battery, a crushing step S22 for crushing a roasted product, and a lumpy substance and a sieving product which are sieved by subjecting the crushed material to a sieving process. It has a sieving step S23 for separating the sieving material into a powder, and a magnetic sorting step S24 for separating the sieving material into a magnetized material and a non-magnetized material by subjecting the sieving material to a magnetic separation process.

That is, in the method according to the second embodiment, the order of the sieving step and the magnetic separation step is different from that in the method according to the first embodiment, and the crushed material is sieved and collected in the sieving step S23. It is characterized in that the powder of the sieved product is subjected to the magnetic separation treatment in the magnetic separation step S24.

The description of the processing in each step is as described in the method of the first embodiment, and therefore the description here will be omitted.

As in the method for recovering valuable metals according to the second embodiment, the crushed material is sieved using a sieve having a predetermined opening, and then the powder to be a sieve product is subjected to a magnetic separation treatment to perform sieving. It is possible to separate and remove an impurity metal component such as iron contained together with a valuable metal in a material as a magnetized material. As a result, the non-magnetized material recovered through the magnetic separation treatment contains a valuable metal having a reduced content of impurities such as iron. Therefore, such non-magnetized material is roasted by oxidation. By performing the treatments in the baking step S25 and the reduction melting step S26, the valuable metal contained in the waste battery can be recovered efficiently and stably.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples.

[Examples, comparative examples]
(Roasting process)
As a waste battery, we prepared a used lithium-ion battery for automobiles with a square outer shape. This waste battery was roasted in an air atmosphere at a temperature of 920 ° C. for 6 hours.

(Crushing process)
Next, in the crushing step, a chain mill was used as a crusher, and the roasted product obtained from the roasting step was crushed into 10 kg per batch. The crushed product obtained by such crushing was recovered and used as it was in the magnetic separation step of the next step.

(Magnetic separation process)
Next, in the magnetic separation step, a hanging magnetic separator was used as the magnetic separator, and the crushed material conveyed and supplied by the belt conveyor was subjected to the magnetic separation process. At this time, the obstruction plate is hung and installed in the upper space of the belt conveyor at a predetermined position (upstream from the hanging magnetic separator), and the size of the crushed material to be conveyed is adjusted in the height direction to adjust the size. Only the crushed material was supplied to the magnetic separator. The adjusted size (sample height) is as shown in Table 1 below. Further, the crushed material was transported at a transport speed of 1.0 kg / min and continuously supplied to a magnetic separator for magnetic separation processing.

On the other hand, in Comparative Example 1, the crushed product was not subjected to the magnetic separation treatment, and the crushed product was supplied to the sieving step as it was.

(Sieve separation process)
Next, in the sieving step, the non-magnetized material (Examples 1 to 7) and the crushed material (Comparative Example 1) obtained through the magnetic separation treatment were weighed, and a metal having a large number of holes having a diameter of 2.0 mm was opened. The (stainless steel) plate was subjected to a sieving machine using a sieve, and the sieving product and the sieving product were separated.

[result]
Table 1 below shows the treatment conditions in Examples 1 to 7 and Comparative Example 1 and the measurement results of the iron (Fe) content contained in the sieving product recovered through the sieving treatment in the sieving step. .. In addition, the results of the composition in the magnetized material recovered through the magnetic separation treatment in the magnetic separation step in Examples 1 to 7 are also shown. The content of each metal element was measured using an ICP emission spectrophotometer.

As shown in Table 1, in Examples 1 to 7 in which the magnetic sorting treatment was performed, the content of Fe in the sieving product recovered by the sieving treatment after the magnetic sorting treatment was low, and the impurity Fe was removed. I was able to obtain a sieve.

On the other hand, in Comparative Example 1 in which the magnetic separation treatment was not performed, the Fe content in the sieved product was very high. It was assumed that it would be difficult to design the melting point, viscosity, etc. of the slag when the sieve melt with a high content of Fe, which is an impurity, is subjected to a reduction melting treatment in a subsequent step.

Further, from the results of Examples 1 to 7, Ni and Ni, which will be distributed in the magnetized material by adjusting the size of the crushed material prior to performing the magnetic separation treatment (Examples 1 to 6). It was found that the amount of valuable metal of Co can be reduced, loss can be suppressed, and valuable metal can be recovered effectively.

1 Crushed material 1A Magnetized material 1B Non-magnetized material 1D Crushed material 1E Crushed material 11 Belt conveyor 12 Suspended magnetic separator 13 (For discharging magnetized material) Belt conveyor 20 Magnet 30 Obstacle plate

Claims (9)

The roasting process for roasting waste batteries and
The crushing process to crush the roasted food and
A magnetic separation process in which the crushed material is subjected to a magnetic separation process to separate it into a magnetized material and a non-magnetized material.
A sieving step of sieving the non-magnetized material and separating it into a sieving product and a sieving product.
A method for recovering valuable metals from waste batteries. In the magnetic separation step, the crushed material is subjected to a magnetic separation process using a hanging magnetic separator.
The method for recovering valuable metals from a waste battery according to claim 1. In the magnetic separation process,
The size of the crushed material is adjusted to be less than or equal to a predetermined value, and the crushed material adjusted in size is subjected to the magnetic separation treatment.
The method for recovering valuable metals from a waste battery according to claim 2. In the magnetic separation process,
Of the crushed materials that are placed on the belt conveyor and transported through the crushing step, the crushed materials that have been adjusted to a certain size or less in the height direction by an obstacle plate installed in the upper space of the belt conveyor. Perform the magnetic separation process.
The method for recovering valuable metals from a waste battery according to claim 3. In the magnetic separation process,
The size of the crushed material in the height direction is adjusted to a range of 20 mm or more and 120 mm or less, and the size-adjusted crushed material is subjected to the magnetic separation treatment.
The method for recovering valuable metals from a waste battery according to claim 3 or 4. An oxidative roasting step of oxidatively roasting the sieve material, and
Further comprising a reduction melting step of reducing and melting an oxidized roasted product to obtain a slag and an alloy containing a valuable metal.
The method for recovering valuable metals from a waste battery according to any one of claims 1 to 5. The valuable metal comprises at least one selected from the group consisting of cobalt, nickel, and copper.
The method for recovering valuable metals from a waste battery according to any one of claims 1 to 6. The roasting process for roasting waste batteries and
The crushing process to crush the roasted food and
A sieving process in which the crushed material is sieved and separated into a sieving product and a sieving product.
A magnetic separation step of subjecting the sieve material to a magnetic separation process to separate it into a magnetized material and a non-magnetized material.
A method for recovering valuable metals from waste batteries. Oxidative roasting step of oxidative roasting the non-magnetized material and
Further comprising a reduction melting step of reducing and melting an oxidized roasted product to obtain a slag and an alloy containing a valuable metal.
The method for recovering valuable metals from a waste battery according to claim 8.

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