JP7413847B2 - Method for recovering valuable metals from waste batteries - Google Patents

Description

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

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

A negative electrode active material such as graphite is fixed to the surface of the negative electrode current collector to constitute 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 constitute a positive electrode material. The negative electrode material and the positive electrode material are charged into the above-mentioned outer can via a separator made of a porous resin film of polypropylene, etc., and the gap contains an electrolyte such as lithium hexafluorophosphate (LiPF ₆ ). Electrolyte etc. are sealed.

Lithium ion batteries are now increasingly being used as in-vehicle batteries for hybrid vehicles, electric vehicles, and the like. However, as the lithium-ion batteries installed in automobiles are used, they gradually deteriorate and are eventually discarded at the end of their service life.

As the power source for automobiles changes from gasoline to electricity, the number of batteries used in automobiles increases, which means that the number of batteries discarded also increases.

Attempts and specific proposals have been made to reuse such discarded lithium-ion batteries and defective products generated during the manufacturing of lithium-ion batteries (hereinafter collectively referred to as "waste batteries") as resources. It's being done a lot. In many cases, the mainstream is a pyrometallurgical process in which waste lithium-ion batteries are put into a high-temperature furnace and then completely melted.

Here, in addition to commercially recyclable elements such as nickel, cobalt, and copper (hereinafter referred to as "valuable metals"), waste batteries include carbon, aluminum, fluorine, phosphorus, and other elements. Contains elements that are not subject to commercial recovery (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, waste batteries are roasted to make them harmless by removing fluorine, phosphorus, etc., then crushed or crushed, and then separated using a sieve or magnetic separator. A pyrometallurgical process (hereinafter also simply referred to as "dry treatment") or a hydrometallurgical process (hereinafter simply referred to as "wet treatment") in which liquids such as acids or organic solvents are used to separate Methods are being used to recover metals.

As a method for recovering cobalt, which is a valuable metal, from waste batteries by dry processing, 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 and valuables are recovered, and then a lime-based solvent (flux) is added to remove phosphorus.

Further, in Patent Document 3, as a method for recycling a battery pack that includes an assembled battery formed by connecting a plurality of single cells in series and a control unit that controls the assembled battery, and has resin parts, an assembled battery in a charged state is disclosed. The process includes a process of roasting the battery pack containing the battery as it is, and a complete combustion process of completely burning the unburned pyrolysis gas generated during the roasting of the battery pack. , a recycling method is disclosed in which assembled batteries in a battery pack are roasted in a non-oxidizing atmosphere or a reducing atmosphere at a temperature higher than the carbonization temperature of the resin forming the resin parts and lower than the melting point of the metal parts of the battery pack. There is.

However, these methods have a problem in that they require a large amount of cost for dehydration and drying processes, the equipment itself, and maintenance.

Furthermore, since waste batteries contain many impurities such as iron, it is essential to eliminate as many impurities as possible in order to efficiently recover valuable metals. However, impurities and valuable metals are often mixed in various forms, and it has not been easy to separate and recover valuable metals reliably and stably with high economic efficiency.

JP2013-091826A Special table 2013-506048 publication Japanese Patent Application Publication No. 2010-3512

The present invention was proposed in view of the above circumstances, and provides a method for efficiently and stably recovering valuable metals contained in waste batteries 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, after crushing the roasted material obtained by roasting waste batteries into a predetermined size, the crushed material is subjected to magnetic separation treatment, and the magnetically separated non-magnetized material is separated through a sieve. We have discovered that valuable metals can be recovered efficiently and stably by collecting waste. Alternatively, it has been found that the same effect can be obtained by subjecting the unsieved material of the crushed material to magnetic separation treatment and collecting 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 process for roasting a waste battery, a crushing process for crushing the roasted product, and a magnetic separation process for the crushed product to separate magnetized and non-magnetized products. This is a method for recovering valuable metals from waste batteries, which comprises a magnetic separation step in which the non-magnetized materials are separated into sieves and separated into sieved materials and sieved materials.

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

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

(4) In the fourth aspect of the present invention, in the third aspect, in the magnetic separation step, among the crushed materials that are placed on the belt conveyor and transported after the crushing step, the upper space of the belt conveyor is This is a method for recovering valuable metals from waste batteries, in which the magnetic separation process is applied to the crushed material, which has been adjusted to a size below a certain height in the height direction using baffles installed in the battery.

(5) A fifth invention of the present invention is that in the third or fourth invention, in the magnetic separation step, 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. This is a method for recovering valuable metals from waste batteries, in which the crushed material is subjected to the magnetic separation process.

(6) A sixth aspect of the present invention is the oxidizing roasting step of oxidizing and roasting the sieved material, and reducing and melting the oxidized roasted material to form slag. A method for recovering valuable metals from waste batteries, further comprising a reduction melting step of obtaining an alloy containing valuable metals.

(7) A seventh invention of the present invention is the waste metal according to any one of the first to sixth inventions, wherein the valuable metal includes 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 includes a roasting step of roasting a waste battery, a crushing step of crushing the roasted product, and a sieving of the crushed product to separate it into upper sieve material and lower sieve material. This is a method for recovering valuable metals from waste batteries, which includes a sieving step and a magnetic separation step in which the sieved material is subjected to magnetic separation treatment to be classified into magnetized materials and non-magnetized materials.

(9) A ninth aspect of the present invention is the oxidizing roasting step of oxidizing and roasting the non-magnetized material, and reducing and melting the oxidized roasted material to contain slag and valuable metals. This is a method for recovering valuable metals from waste batteries, further comprising a reduction melting step to obtain an alloy.

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

It is a process diagram showing an example of the flow of a valuable metal recovery method. FIG. 2 is a diagram for explaining a hanging magnetic separator provided above a predetermined location on a conveyance path of a belt conveyor. A baffle plate is installed in the upper space of the conveyance route of the belt conveyor at a predetermined location (upstream of the hanging magnetic separator) to prevent crushed materials being conveyed that are smaller than a certain size in the height direction from passing through. FIG. It is a process diagram 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 "this embodiment") will be described in detail. Note that the present invention is not limited to the following embodiments, and various changes can be made without departing from the gist of the present invention.

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

Specifically, this valuable metal recovery method involves crushing the roasted material obtained by roasting waste batteries into a predetermined size in order to render it harmless, and then subjecting the crushed material to magnetic separation treatment to magnetize it. Then, the non-magnetized material is sieved through a sieve with a predetermined mesh size to separate the material above the sieve and the material below the sieve. After that, the separated sieve material is oxidized and roasted, and the oxidized and roasted material is reduced and melted to obtain slag and an alloy containing valuable metals.

In addition, as another embodiment of the method for recovering valuable metals, the roasted material obtained by roasting waste batteries to render it harmless is crushed into a predetermined size, and then the crushed material is passed through a sieve with a predetermined mesh size. The material is sieved and separated into the upper material and the material under the sieve, and then the separated material under the sieve is subjected to magnetic separation treatment to be separated into magnetized material and non-magnetized material. After that, the separated non-magnetized materials are oxidized and roasted, and the oxidized and roasted materials are reduced and melted to obtain slag and an alloy containing valuable metals.

According to these methods, by subjecting the crushed material to magnetic separation treatment, or by performing magnetic separation treatment to the unsieved material obtained by sieving the crushed material, it is possible to eliminate the Impurity metal components, mainly iron, can be effectively removed. In this way, mainly because iron can be effectively removed, it is easy to design the melting point, viscosity, etc. of the slag during reduction and melting in the subsequent process, and valuable metals can be efficiently recovered. Further, treatment for removing impurities such as iron in a post-process becomes unnecessary, and treatment costs can be reduced.

As mentioned above, waste batteries refer to used secondary batteries such as lithium ion batteries, defective products generated in the manufacturing process of positive electrode materials that make up secondary batteries, and residues inside the manufacturing process. This concept includes waste materials generated during the manufacturing process of lithium ion batteries, such as scraps. As mentioned above, such waste batteries contain valuable metals such as nickel, cobalt, copper, etc., which 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 includes a roasting step S11 of roasting a waste battery, a crushing step S12 of crushing the roasted material, and a magnetic separation process on the crushed material to classify it into magnetized materials and non-magnetized materials. and a sieving step S14 in which the magnetically separated non-magnetized material is subjected to a sieving process to separate it into lumps that will be the upper sieve material and powder that will be the lower sieve material. Here, valuable metals such as nickel and cobalt are metals contained in the positive electrode active material, and are recovered in powder form after being separated from impurities such as iron through these steps. Therefore, valuable metals are largely distributed in the sieve material.

Further, an oxidation roasting step S15 in which the obtained sieved material is oxidized and roasted, and a reduction melting step S16 in which slag and an alloy (metal) containing valuable metals are obtained by reducing and melting the oxidized roasted material. , further has.

Furthermore, by subjecting the valuable metal alloy obtained through a series of dry treatments to wet treatments such as neutralization, solvent extraction, and electrowinning, impurities remaining in the alloy can be removed. 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 fluorine components, which are electrolyte components contained in the waste battery, to render 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 in order to ensure detoxification and to make the waste battery brittle so that it can be easily crushed in the next process. It is preferable. Note that the upper limit of the roasting temperature is not particularly limited, but is preferably 1200°C or less. If the roasting temperature is too high, some of the iron used mainly for the outer shell of waste batteries will adhere to the inner walls of the roasting furnace body, such as a kiln, and this may interfere with smooth operation. Otherwise, it may lead to deterioration of the kiln itself, which is undesirable.

Furthermore, if waste batteries to be roasted are piled up too much in a furnace, the insides cannot be sufficiently roasted, resulting in uneven roasting. Therefore, from the viewpoint of ensuring uniform roasting, it is preferable to select the throughput, heating capacity of the roasting furnace, etc. For example, it is preferable to conduct a preliminary test in advance to determine the optimum temperature and roasting time.

The heating method during roasting is not particularly limited, and may be an electric type or a burner type using fuel such as oil or gas. In particular, burner type heating is preferred because it is 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 process is not particularly limited, and for example, a rod mill, jaw crusher, twin-screw kneader, chain mill, etc. can be used.

[Magnetic selection 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 process to classify it into magnetized material and non-magnetized material. The process in the magnetic separation step S13 is to separate and remove metals, mainly iron, which are impurities contained in the waste battery, as magnetized substances.

Here, if iron as an impurity is contained in the recovered valuable metal, the design of the melting point, viscosity, etc. of the slag becomes complicated during the pyrometallurgical smelting in the subsequent reduction and melting step S16. Furthermore, if iron cannot be sufficiently removed from the recovered valuable metals, a separate treatment to remove iron will be required in a post-process, and the treatment cost will increase.

In this regard, according to the valuable metal recovery method according to the present embodiment, a magnetic separation step S13 is provided, the crushed materials are subjected to magnetic separation treatment, and the separated non-magnetized materials are supplied to the next step to remove valuable metals. I'm trying to collect it. Therefore, impurity metal components such as iron, which are classified as magnetized substances, can be effectively removed. In addition, since it is possible to prevent the inclusion of iron in the valuable metals to be recovered, it is easier to design the reduction melting treatment in the subsequent process, and there is no need for treatment to remove iron, which reduces the increase in treatment costs. be able to.

The method of magnetic separation treatment is not particularly limited, but it can be carried out, for example, by a method using a hanging type magnetic separator. FIG. 2 is a diagram for explaining a hanging magnetic separator provided above a predetermined location on a conveyance path of a belt conveyor.

As shown in FIG. 2, the hanging type magnetic separator 12 is configured with a magnet 20 suspended above the conveyance path of the belt conveyor 11, and a separate magnet 20 for discharging magnetized materials is installed around the magnet. A belt conveyor 13 is attached so as to wrap around the magnet 20. The conveyance direction of the belt conveyor 11 is from the front of the page to the back of the page, and a suspended magnetic separator 12 is installed at the upper part of the path in the conveyance direction.

As shown in FIG. 2, the crushed material 1 obtained through the crushing step S2 is conveyed to the next step by a belt conveyor 11, and the By the lowering type magnetic separator 12, impurities such as iron in the crushed material 1 are magnetized to the magnet 20 to become a magnetized material 1A, and crushed material containing valuable metals is not magnetized to the magnet 20 and becomes a non-magnetized material. Each is classified as 1B.

By performing the magnetic separation process using the hanging type magnetic separator 12 in this way, the magnetized materials 1A such as iron attracted to the magnet 20 are moved away from the periphery of the magnet 20 by the belt conveyor 13 for discharging magnetized materials. Therefore, valuable metals and impurity metal components such as iron can be separated more reliably and efficiently.

In magnetic separation processing using a hanging type magnetic separator, in addition to the magnetic force of the magnet, the distance in the height direction between the magnet and the crushed material determines the removal rate of impurities such as iron and the separation of valuable metals and impurities. have a significant impact on the rate. For example, when processing a large amount of waste batteries, inevitably some of them will be insufficiently roasted or crushed, and large chunks will be passed through a magnetic separator. At this time, conventional general magnetic separation treatment cannot sufficiently effectively separate valuable metals and impurities such as iron from coarse crushed materials, and cannot perform stable treatment. Therefore, valuable metals are often distributed to the magnetized object together with the can body made of iron or the like.

Therefore, in this valuable metal recovery method, in the magnetic separation step S13, the size of the crushed material is adjusted to be smaller than a predetermined value, and the size-adjusted crushed material is subjected to magnetic separation processing using a magnetic separator. is preferred. Further, it is preferable that the amount of crushed material fed to the magnetic separator is also constant.

As a method for adjusting the size of the crushed material, for example, as shown in the schematic diagram of FIG. A baffle plate 30 whose height from the belt conveyor 11 is adjusted is installed in the space, and objects of a certain size or less in the height direction are passed through and supplied to the hanging magnetic separator 12. According to such a method, the crushed object 1 that has passed through the baffle plate 30 becomes a crushed object 1D whose size is equal to or less than the installation height of the baffle plate 30 (height of the lower end 30a), Only the crushed material 1D is supplied to the hanging magnetic separator 12 (transported below the hanging magnetic separator 12) and subjected to magnetic separation processing.

On the other hand, coarse crushed materials 1E exceeding a certain size in the height direction are blocked by the baffle plate 30 provided on the belt conveyor 11 and collected, and are not supplied to the hanging magnetic separator 12. Become. In addition, by crushing the coarse crushed material 1E removed by such a baffle plate 30 again and subjecting it to magnetic separation treatment, it is possible to efficiently remove impurities such as iron and reduce 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 applying magnetic separation treatment to the crushed material adjusted to such a size, impurity metal components such as iron can be more reliably removed by being magnetized by the magnet of the magnetic separator, making it more effective and valuable. Can be separated from metal.

Note that the size of the crushed material in the height direction 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.

[Sieving process]
In the sieving step S14, the non-magnetized material that has been magnetically sorted and classified in the magnetic separation step S13 is sieved and separated into upper sieve material and lower sieve material using a sieve (sieve machine) with a predetermined mesh size. . Particularly in the case of waste batteries, the positive electrode active material containing a large amount of valuable metals is crushed into powder and distributed under the sieve. Therefore, valuable metals can be efficiently recovered by separating the materials into under-sieve materials and upper-sieve materials by sieving.

In the valuable metal recovery method according to the present embodiment, the non-magnetized material that has been subjected to magnetic separation treatment in the magnetic separation step S13 of the previous step to remove impurity metal components such as iron is the subject of sieving. The recovered unsieved material contains valuable metals with suppressed impurities.

The sieving process is not particularly limited, and can be performed using a commercially available sieve. Further, the opening of the sieve (opening of the screen), etc. can be appropriately set based on the conditions for separating the upper material and the lower material. Note that if the opening of the sieve is too large, a large amount of non-valuable metals may be recovered together with valuable metals under the sieve, which is not preferable. Moreover, if the opening of the sieve is too small, a large amount of valuable metal may be contained on the sieve, which is not preferable. For example, it is preferable that the opening of the sieve is 5 mm or less because valuable metals can be efficiently recovered.

It is preferable that the sieve is placed in a closed space so that crushed materials are not scattered around. By being able to supply crushed materials to the sieve in a sealed state in this way, it is possible to more efficiently prevent the scattering of powdered materials and the associated loss of valuable metal recovery, and also improve safety and work. It is also preferable from an environmental point of view.

[Oxidation roasting process]
Next, in the oxidative roasting step S15, the unsieved material obtained in the sieving step S14 is roasted in an oxidizing atmosphere. By the roasting treatment in the oxidation roasting step S15, the carbon component (carbon) contained in the sifted material can be oxidized and removed. Specifically, the carbon content in the obtained oxidized roasted product is 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 that are locally generated in the next step, the reduction melting step S16, are prevented from being physically impeded by carbon. This makes it possible to agglomerate without any agglomeration and can be recovered as an integrated alloy. Further, in the reduction and melting step S16, reduction of phosphorus contained in the contents of the battery by carbon can be suppressed, and phosphorus can be effectively oxidized and removed to prevent it from being distributed in the alloy of valuable metals.

In the oxidative roasting step S15, oxidative roasting is performed at a temperature of 600° C. or higher (oxidative roasting temperature), for example. By setting the roasting temperature to 600° C. or higher, carbon contained in the battery can be effectively oxidized and removed. Further, by preferably setting the temperature to 700°C or higher, the processing time can also be shortened. Further, the upper limit of the oxidation roasting temperature is preferably 900° C. or less, thereby making it possible to suppress thermal energy costs and improve processing efficiency.

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 next step, reduction melting step S16, and carry out the melting in the preliminary furnace. As the roasting furnace, any type of kiln capable of carrying out oxidation treatment (roasting) by heating the crushed material while supplying oxygen can be used. As an example, a known rotary kiln, tunnel kiln (hearth furnace), etc. can be suitably used.

[Reduction melting process]
In the reduction melting step S16, the oxidized roasted product obtained by the roasting treatment in the oxidation roasting step S15 is reduced and melted to obtain slag containing impurities and an alloy (metal) containing valuable metals. In the reduction and melting step S16, the oxides of impurity elements obtained by oxidation in the oxidation roasting treatment are left as they are, and the oxides of valuable metals that have been oxidized in the oxidation roasting treatment are reduced and melted. By doing so, it is possible to obtain an alloy in which impurities are separated and reduced products are integrated. Note that the alloy obtained as a melt is also referred to as a "molten alloy."

In the reduction melting step S16, the treatment can be performed in the presence of carbon, for example. Carbon is a reducing agent that has the ability to easily reduce the valuable metals to be recovered, such as nickel and cobalt; for example, 1 mole of carbon can reduce 2 moles of valuable metal oxides such as nickel oxide. Examples include graphite. Further, hydrocarbons capable of reducing 2 to 4 moles per mole of carbon can also be used as the carbon supply source. In this way, by reducing and melting in the presence of carbon as a reducing agent, valuable metals can be efficiently reduced and an alloy containing valuable metals can be effectively obtained.

As carbon, in addition to artificial graphite and natural graphite, coal, coke, etc. can also be used as long as impurities are tolerable in the product and post-process. Further, during the reduction melting process, it is desirable to appropriately adjust the amount of carbon present. Specifically, preferably, the proportion is more than 7.5% by mass and 10% by mass or less, more preferably 8.0% by mass or more and 9.0% by mass or less, based on 100% by mass of the oxidized roasted material to be treated. It melts in the presence of carbon in proportions such that

The temperature conditions (melting temperature) in the reduction melting treatment are not particularly limited, but are preferably in the range of 1320°C or more and 1600°C or less, more preferably in the range of 1450°C or more and 1550°C or less. Further, in the reduction melting treatment, an oxide flux may be added and used. Note that in the reduction melting process, dust, exhaust gas, etc. may be generated, but they can be made harmless by performing conventionally known exhaust gas treatment.

<2-2. Second embodiment>
FIG. 4 is a process diagram showing an example of the flow of a valuable metal recovery method according to another embodiment. This valuable metal recovery method includes a roasting step S21 of roasting a waste battery, a crushing step S22 of crushing the roasted material, and a sieving process for the crushed material to remove lumps and sieve material. The method includes a sieving step S23 in which the powder is separated into powder, and a magnetic separation step S24 in which the sieved material is subjected to magnetic separation treatment to be classified into magnetized materials and non-magnetized materials.

That is, in the method according to the second embodiment, the order of the sieving step and the magnetic separation step is different from the method according to the first embodiment, and the crushed material is sieved and collected in the sieving step S23. The present invention is characterized in that the powder of the sieved material is subjected to a magnetic separation process in a magnetic separation step S24.

The explanation of the processing in each step is as explained in the method of the first embodiment, so the explanation here will be omitted.

As in the method for recovering valuable metals according to the second embodiment, after the crushed material is sieved using a sieve with a predetermined mesh size, magnetic separation is performed on the powder that becomes the under-sieve material. Impurity metal components such as iron that are contained together with valuable metals in a substance can be separated and removed as magnetized substances. As a result, the unmagnetized materials recovered through the magnetic separation process contain valuable metals with reduced impurity content such as iron. By performing the processing in the firing step S25 and the reduction melting step S26, valuable metals contained in the waste battery can be efficiently and stably recovered.

EXAMPLES Hereinafter, the present invention will be explained in more detail using Examples and Comparative Examples, but the present invention is not limited to the following Examples.

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

(Crushing process)
Next, in the crushing process, a chain mill was used as a crusher to crush the roasted material obtained from the roasting process, with each batch weighing 10 kg. The crushed material obtained by such crushing was collected and directly subjected to the next magnetic separation step.

(Magnetic selection process)
Next, in the magnetic separation process, a hanging magnetic separator was used as the magnetic separator, and the crushed materials conveyed and supplied by the belt conveyor were subjected to magnetic separation processing. At this time, a baffle plate is suspended and installed in the upper space of the belt conveyor at a predetermined position (upstream side of the hanging magnetic separator), and the size of the crushed material to be conveyed in the height direction is adjusted. Only the crushed material that has been crushed is fed to the magnetic separator. The adjusted size (height of the sample) was as shown in Table 1 below. Further, the crushed material was transported at a transport speed of 1.0 kg/min, and was continuously supplied to a magnetic separator for magnetic separation treatment.

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

(sieving process)
Next, in the sieving step, the non-magnetized materials (Examples 1 to 7) and the crushed materials (Comparative Example 1) obtained through the magnetic separation treatment were weighed, and the metals with many holes with a diameter of 2.0 mm were weighed. A (stainless steel) plate was passed through a sieve machine using a sieve to separate the material under the sieve and the material above the sieve.

[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 unsieved material recovered through the sieving process in the sieving process. . In addition, the results of the composition of the magnetized materials recovered through the magnetic separation process in Examples 1 to 7 are also shown. Note that the content of each metal element was measured using an ICP emission spectrometer.

As shown in Table 1, in Examples 1 to 7 in which magnetic separation treatment was performed, the content of Fe in the sieved matter recovered in the sieving treatment after magnetic separation treatment was low, and impurity Fe was removed. I was able to obtain the sieve material.

On the other hand, in Comparative Example 1 in which magnetic separation treatment was not performed, the content of Fe in the sieved material was extremely high. It was assumed that if a reduction melting treatment was performed in a post-process on the sifted material with a high content of Fe, which is an impurity, it would be difficult to design the melting point, viscosity, etc. of the slag.

In addition, from the results of Examples 1 to 7, it was found that by adjusting the size of the crushed materials prior to magnetic separation treatment (Examples 1 to 6), Ni and Ni were distributed in the magnetized materials. It has been found that the amount of valuable metal Co can be reduced, loss can be suppressed, and valuable metal can be effectively recovered.

1 Crushed material 1A Magnetized material 1B Non-magnetized material 1D Crushed material 1E Crushed material 11 Belt conveyor 12 Hanging type magnetic separator 13 Belt conveyor (for discharging magnetized material) 20 Magnet 30 Baffle plate

Claims (4)

A roasting process for roasting waste batteries;
A crushing process of crushing the roasted product;
A magnetic separation step in which the crushed material is subjected to magnetic separation treatment using a magnetic force that allows it to be classified into magnetized materials made of impurity metals containing iron and non-magnetized materials made of valuable metals containing at least cobalt and/or nickel;
a sieving step of sieving the non-magnetized material to separate it into an upper sieve material and a lower sieve material;
has
In the magnetic selection process,
The crushed material obtained in the crushing step is placed on a belt conveyor for transporting crushed materials, and the crushed materials are transported by a baffle plate installed in the upper space on the upstream side of the belt conveyor for transporting crushed materials. Adjust to below a certain size in the height direction,
A magnet is suspended in the upper space on the downstream side of the crushed material conveying belt conveyor at a height where it does not come into contact with the crushed material whose size in the height direction is adjusted. Using a hanging magnetic separator, the crushed material is subjected to magnetic separation treatment,
Magnetized object conveyance is configured by attaching the magnetized object magnetized to the magnet by the magnetic separation process so as to wrap around the magnet, and the conveyance direction is different from the conveyance direction of the crushed object conveyance belt conveyor. for removal via belt conveyor,
Method for recovering valuable metals from waste batteries. an oxidative roasting step of oxidizing and roasting the unsieved material;
Further comprising a reduction melting step of reducing and melting the oxidized roasted product to obtain slag and an alloy containing a valuable metal.
The method for recovering valuable metals from waste batteries according to claim 1 . A roasting process for roasting waste batteries;
A crushing process of crushing the roasted product;
a sieving step in which the crushed material is sieved and separated into upper sieve material and lower sieve material;
A magnetic separation step in which the sieved material is subjected to a magnetic separation treatment using a magnetic force that can classify the material into a magnetized material made of an impurity metal containing iron and a non-magnetized material made of a valuable metal containing at least cobalt and/or nickel;
has
In the magnetic selection process,
The unsieved material obtained in the sieving step is placed and conveyed on a belt conveyor for conveying the unsieved material, and a baffle plate installed in the upper space on the upstream side of the unsieved material conveying belt conveyor, Adjust the unsieved material to a certain size or less in the height direction,
For the unsieved material whose size in the height direction has been adjusted, a magnet is suspended in the upper space on the downstream side of the belt conveyor for conveying the unsieved material at a height that does not come into contact with the unsieved material being conveyed. Using a hanging magnetic separator configured with a magnetic separator, the sieved material is subjected to magnetic separation treatment,
A magnetized object that is configured by attaching a magnetized object magnetized to the magnet by the magnetic separation process so as to wrap around the magnet, and whose conveyance direction is different from the conveyance direction of the belt conveyor for conveying the unscreened materials. removed via a conveyor belt,
Method for recovering valuable metals from waste batteries. an oxidative roasting step of oxidizing and roasting the non-magnetized material;
Further comprising a reduction melting step of reducing and melting the oxidized roasted product to obtain slag and an alloy containing a valuable metal.
The method for recovering valuable metals from waste batteries according to claim 3 .

Images