JP6966960B2 - Lithium-ion battery waste disposal method - Google Patents

Description

The present invention relates to a method for treating lithium ion battery waste, which is obtained by crushing and sieving lithium ion battery waste.

Most of the lithium ion batteries used in many industrial fields including various electronic devices use a lithium metal salt containing manganese, nickel and cobalt as a positive electrode active material, and a positive electrode material containing the positive electrode active material and a positive electrode material. The negative electrode material is wrapped in a housing containing aluminum. In recent years, with the increase in the amount used and the range of use, the amount discarded due to the product life of the battery or defects in the manufacturing process has increased. The situation is increasing.
Under such circumstances, it is desired to easily recover the above-mentioned valuable metals such as nickel and cobalt from the lithium-ion battery waste that is discarded in large quantities at a relatively low cost for reuse.

As an example of a method for recovering valuable metals from lithium-ion battery waste, first, the lithium-ion battery waste is roasted, the roasted lithium-ion battery waste is crushed, and then the crushed material is sieved. To remove impurities such as copper and aluminum to some extent.
Next, the powdered battery powder obtained under the sieve after sieving is added to the leachate and leached, and lithium, nickel, cobalt, manganese, copper, aluminum and the like that can be contained therein are dissolved in the solution.

After that, each metal element dissolved in the leached liquid obtained by leaching as described above is separated. Here, in order to separate each metal leached into the leached liquid, for example, the leached liquid is subjected to a plurality of steps of solvent extraction according to the metal to be separated.

Among such methods for recovering valuable metals, there is a technique described in Patent Document 1 as a technique for crushing lithium ion battery waste and sorting crushed substances. Subsequent leaching, solvent extraction and the like are described in, for example, Patent Documents 2 and 3.

JP-A-2015-195129 Japanese Unexamined Patent Publication No. 2005-149889 Japanese Unexamined Patent Publication No. 2009-193778

By the way, when crushing lithium-ion battery waste, when a crushed product obtained by crushing lithium-ion battery waste into extremely fine powders and granules is obtained, impurities such as copper become finer and are often placed under a separate sieve. Mixed. When the powder or granular material under the sieve containing a large amount of such impurities is leached, the impurities are also dissolved in the leaching solution, and the burden of removing the impurities in the subsequent recovery increases.
On the other hand, in a crushed product in which lithium ion battery waste is roughly crushed and contains a large amount of relatively coarse powders and granules, a large amount of valuable metal also remains on the sieve, and the recovery rate of the valuable metal is lowered.

Here, in Patent Document 1, "a mixture of a positive electrode material and a negative electrode material of a used lithium ion battery is crushed to several mm or less to peel off the active material from the current collector of the electrode material, and this crushed mixture is used. By sieving, the medium particles mainly composed of crushed current collector and the fine particles mainly composed of crushed active material are separated, and the fine particles are collected, while the medium particles are sorted by specific gravity and made of aluminum. Separate and recover a lightweight substance mainly composed of a lightweight substance and a heavy substance mainly composed of copper. It is screened into a product, a medium-sized product having a thickness of 5 mm or less to 0.5 mm or more, and a fine-sized product having a size of less than 0.5 mm. "

In this Patent Document 1, there are three types having different sizes: coarse particles having a particle size larger than 5 mm, medium particles having a particle size of 5 mm or less to 0.5 mm or more, and fine particles having a particle size of less than 0.5 mm in secondary crushing. The medium particles are sorted by specific gravity as they are or by adjusting the particle size. In this case, since the relatively coarse valuable metal that can be contained in the medium particles cannot be recovered, the recovery rate cannot be greatly improved.
Further, in Patent Document 1, after the primary crushing (coarse crushing) and before the secondary crushing, only the process of "removing resins and magnetic deposits by wind power sorting or magnetic separation" is performed. Therefore, as described above, if the degree of both primary crushing and secondary crushing described in Cited Document 1 is light, it is undeniable that the recovery rate of valuable metals is lowered, and if the degree of both crushing is heavy. , The burden of removing impurities increases.

An object of the present invention is to solve such a problem, and an object of the present invention is to provide a method for treating lithium ion battery waste capable of effectively sieving a predetermined metal by sieving. There is something in it.

As a result of diligent studies, the inventor crushed the lithium ion battery waste so that a crushed material containing a certain amount of relatively large particle size powders could be obtained in the crushing step, and then sieve the crushed material. In a separate step, at least three types of small-diameter powder particles, medium-diameter powder particles, and large-diameter powder particles having different particle sizes are sieved, and then the medium-diameter powder particles are again sorted. It was found that a predetermined metal can be effectively sieved under a sieve by carrying out a re-crushing and sieving step of crushing and sieving.

Based on this finding, the method for treating lithium ion battery waste of the present invention is a method of crushing and sieving the lithium ion battery waste, and crushing the lithium ion battery waste using a crusher. A crushing step of obtaining a crushed material containing a powder or granular material and having a powder or granular material having a particle size larger than 1 mm occupying an amount of more than 26.3% of the total powder or granular material. At least, a small-diameter powder or granular material having a relatively small particle size, a large-diameter powder or granular material having a relatively large particle size, and a medium particle size between the small-diameter powder or granular material and the large-diameter powder or granular material. sieving steps divided into a径粉granules, and, after obtaining re-crushed material by crushing the in径粉granules, see contains a re-crushing sieving step of sieving the re crushed material, the re In the crushing and sieving step, the re-crushed material is at least a small-diameter powder or granular material having a relatively small particle size, a large-diameter powder or granular material having a relatively large particle size, and a small-diameter powder or granular material having a relatively large particle size. The medium-diameter powder or granular material, which is intermediate between the large-diameter powder or granular material, is separated from the medium-diameter powder or granular material, and the re-crushing and sieving step is repeated .

According to the method for treating lithium ion battery waste of the present invention, the lithium ion battery waste is crushed using a crusher, and the amount of powder or granular material having a particle size larger than 1 mm is more than 26.3% of the total powder or granular material. A crushing step to obtain a crushed material that occupies a large amount, a sieving step to sieve the crushed material into small-diameter powder particles, medium-diameter powder particles, and large-diameter powder particles, and crushing the medium-diameter powder particles. After obtaining the re-crushed material, the predetermined metal can be effectively sieved by including the re-crushed sieving step of sieving the re-crushed material.

It is a flow diagram which shows the series of processes which can use the method of treating the lithium ion battery waste which concerns on one Embodiment of this invention. It is a flow chart which shows the process of the comparative example. It is a flow figure which shows the process of the invention example. It is a graph which shows the change of the integrated distribution rate of Co and the integrated distribution rate of Cu, respectively, with the increase of the number of times of crushing of the invention example. It is a graph which shows the integrated grade of each of Co and Cu with the increase in the number of times of crushing of an invention example, together with the integrated processing amount ratio.

Hereinafter, embodiments of the present invention will be described in detail.
In the method for treating lithium ion battery waste according to an embodiment of the present invention, when the lithium ion battery waste is crushed and sieved for treatment, the lithium ion battery waste is crushed using a crusher and powdered. It includes a crushing step of obtaining a crushed product containing grains, a sieving step of sieving the crushed material, and a sieving step of further crushing and sieving the crushed material.

In particular, here, in the crushing step, by using a predetermined crusher or the like, a crushed material in which the powder or granular material having a particle size larger than 1 mm occupies more than 26.3% of the total powder or granular material is obtained, and In the sieving step, at least a small-diameter powder or granular material having a relatively small particle size, a large-diameter powder or granular material having a relatively large particle size, and the small-diameter powder or granular material and the large-diameter powder or granular material having a relatively large particle size are used. It is important to divide it into medium-diameter powders and granules, which are in the middle of the above. Then, in the re-crushing and sieving step, the medium-diameter powders and granules obtained in the sieving step are crushed to obtain a re-crushed product, and then the re-crushed product is sieved.
This embodiment can be used in a series of processes illustrated in FIG. Here, each process and the like will be described in detail along this process.

(Lithium-ion battery waste)
The lithium-ion battery waste targeted in this embodiment is a lithium-ion battery waste that can be used in various machines or devices such as mobile phones and other various electronic devices and automobiles. More specifically, for example, those that are discarded or recovered due to the life of battery products, manufacturing defects, or other reasons, and by targeting such lithium-ion battery waste, we aim to make effective use of resources. be able to.

Lithium-ion battery waste includes positive electrode active materials that are lithium metal salts containing manganese, nickel, and cobalt, as well as negative electrode materials containing carbon, iron, and copper, and positive electrode active materials, such as polyvinylidene fluoride (PVDF). It may include an aluminum foil (positive electrode base material) coated and fixed by another organic binder or the like, and a housing containing aluminum as an exterior wrapping around the lithium ion battery waste. Specifically, in a lithium ion battery, a single metal oxide composed of one element of lithium, nickel, cobalt, and manganese constituting a positive electrode active material and / or a composite metal oxidation composed of two or more elements. Objects, as well as aluminum, copper, iron, carbon and the like can be included.

The lithium-ion battery waste wrapped in the housing can have a substantially square or rectangular planar contour shape, in which case the untreated dimensions are, for example, 40 mm to 80 mm in length. Those having a width of 35 mm to 65 mm and a thickness of 4 mm to 5 mm can be targeted, but are not limited to those having such dimensions and shapes.

(Roasting process)
In the roasting step, the above-mentioned lithium ion battery waste is roasted. This roasting process raises the temperature of the lithium-ion battery waste and removes the electrolyte inside to make it harmless, and generally decomposes the binder that binds the aluminum foil and the positive electrode active material. It promotes the separation of the aluminum foil and the positive electrode active material during crushing and sieving, increases the recovery rate of the positive electrode active material collected under the sieve, and further reduces the valuable metal contained in the lithium ion battery waste. , The purpose is to change the form so that it can be easily leached in the leaching step.

In the roasting process, lithium-ion battery waste is usually heated at 450 ° C. or higher. As a result, the lithium metal salt of the positive electrode active material (LiCoO _{2 in} the case of cobalt type) is decomposed, and a large amount of cobalt can be in the form of cobalt oxide (CoO) or simple cobalt which is easily acid-leached. On the other hand, if the temperature at this time is too high, aluminum having a melting point of 660 ° C. melts. Therefore, the temperature is set to about 450 ° C. to 650 ° C., for example, measured by the surface temperature of the housing of the lithium ion battery waste. This temperature can be maintained for about 20 to 120 minutes.
The roasting step can be omitted.

(Crushing process)
Next, in general, the housing of the lithium ion battery waste is destroyed, and a crushing step is performed in order to turn the lithium ion battery waste into a crushed product composed of predetermined small powders and granules.
In this crushing step, the type of crusher and other crushing conditions are selected so that the crushed material in which the powder or granular material having a particle size larger than 1 mm occupies more than 26.3% of the total powder or granular material can be obtained.

By crushing the lithium-ion battery waste with a relatively weak crushing force so that the powder or granular material having such a large particle size is contained in a predetermined amount, the metal as a copper foil or the like can be contained in the lithium-ion battery waste. Copper, which is an impurity that is often contained in the form, does not proceed to crushing and becomes a powder or granular material having a large particle size to some extent. On the other hand, valuable metals such as cobalt, which can be contained in the lithium-ion battery waste in the form of oxides, are crushed sufficiently small even with such a weak crushing force, so that the powder particles have a relatively small particle size. Become a body. Thereby, these can be effectively separated in the sieving step described later.

The crushed material obtained by crushing the lithium ion battery waste with a crusher is mainly composed of powder or granular material, and the powder or granular material is generally 0.005 mm to 20 mm, typically 0.010 mm or more. It may have a particle size of 5 mm.

In the crushed material containing such powder or granular material, the ratio of the powder or granular material having a particle size larger than 1 mm to the entire powder or granular material is set to be more than 26.3% by mass fraction. If the particle size of the powder or granular material exceeds 1 mm is 26.3% or less, it is presumed that not only valuable metals such as cobalt but also impurities such as copper are crushed into small pieces as a result of the crushing force being too strong. Therefore, it is considered that the amount of impurities mixed under the sieve in the subsequent sieving step is often increased. From this viewpoint, it is preferable that the crushed material contains more than 26.3% of the powder or granular material having a particle size larger than 1 mm with respect to the entire powder or granular material.

In the scope of this specification and patent claims, the term "granular material larger than a predetermined particle size" means a powder or granular material that does not pass through a mesh having a size corresponding to the particle size. When the powder or granular material has a predetermined particle size or less, it means a powder or granular material that passes through a mesh having a size corresponding to the particle size. Therefore, for example, a powder or granular material having a particle size larger than 1 mm is a powder or granular material that does not pass through a sieve having an opening of 1 mm. This sieve is a standard sieve specified in JIS Z8810, but is not particularly limited.

The crusher used in the crushing step can be various devices or equipment, but it is particularly preferable to use a uniaxial or biaxial rotor rotary crusher. Since such a rotor rotary crusher can crush lithium ion battery waste with a weak crushing force, it is often an oxide while using copper such as metal as a powder or granular material having a large particle size. Other valuable metals can be crushed sufficiently finely and separated more effectively in a later sieving step.

Further, the clearance of the uniaxial or biaxial rotor rotary crusher is preferably 15 mm to 20 mm. If the clearance is less than 15 mm, the required processing time increases and there is a concern that the work efficiency may decrease. On the other hand, if the clearance exceeds 20 mm, the crushing efficiency of the valuable metal may decrease. The clearance here means a gap between blades.

However, as described above, another crusher can be used as long as the powder or granular material having a particle size larger than 1 mm can obtain a crushed product in which more than 26.3% of the total powder or granular material can be obtained. Other crushers include, for example, impact type crushers that can crush lithium-ion battery waste by applying impact while cutting it, specifically, sample mills, hammer mills, pin mills, wing mills, and tornado mills. , Hammer crusher and the like.
A screen can be installed at the outlet of the crusher, whereby the lithium ion battery waste is discharged from the crusher through the screen when it is crushed to a size that allows it to pass through the screen.

(Sieving process)
After passing through the crushing step as described above, the crushed product obtained there is subjected to a sieving step using a predetermined sieve.
In the sieving step, as shown in FIG. 1, at least the crushed material is divided into a small-diameter powder or granular material having a relatively small particle size, a large-diameter powder or granular material having a relatively large particle size, and a small-diameter particle size. It is separated into a medium-diameter powder or granular material, which is intermediate between the powder or granular material and the large-diameter powder or granular material.

Here, impurities such as copper become powders and granules having a relatively large particle size due to the previous crushing step, and valuable metals such as cobalt become powders and particles having a relatively small particle size. Is separated as the above-mentioned large-diameter powder or granular material, while most of the valuable metals are separated as the above-mentioned small-diameter powder or granular material. Further, since impurities and valuable metals are mixed in the medium-diameter powder or granular material, the re-crushing and sieving step described later is further performed on the medium-diameter powder or granular material. As illustrated in FIG. 1, small-diameter powders and granules containing a large amount of valuable metals can be sent to a recovery step for recovering such valuable metals, and large-diameter powders and granules mainly containing a large amount of impurities such as copper. The body can be sent to the copper smelting process.

The upper limit of the particle size of the small-diameter powder or granular material, which is the boundary between the small-diameter powder or granular material and the medium-diameter powder or granular material, is preferably set to 5 mm to 0.1 mm. If the upper limit of the particle size of the small-diameter powder or granular material is too small, the valuable metal that has become small to some extent will also be contained in the medium-diameter powder or granular material, and the load of the subsequent re-crushing and sieving step for recovering this will be applied. May increase. On the other hand, if the upper limit of the particle size of the small-diameter powder or granular material is too large, it is undeniable that a relatively large amount of impurities may be contained in the small-diameter powder or granular material. There is concern that it cannot be reduced so effectively.

Further, the upper limit of the particle size of the medium-diameter powder or granular material, which is the boundary between the medium-diameter powder or granular material and the large-diameter powder or granular material, is preferably set to 20 mm to 5 mm. If the upper limit of the particle size of the medium-diameter powder or granular material is reduced, it is considered that the large-diameter powder or granular material contains a large amount of valuable metals, and it is presumed that the recovery rate cannot be sufficiently improved. Further, if the upper limit of the particle size of the medium-diameter powder or granular material is increased, the load of the re-crushing and sieving step may increase as a result of the medium-diameter powder or granular material containing relatively coarse impurities.

From the above-mentioned viewpoints, in particular, the small-diameter powder or granular material has a particle size of 1 mm or less, and the medium-diameter powder or granular material has a particle size of more than 1 mm and 3.35 mm or less. Most preferably, the body has a particle size larger than 3.35 mm.
In addition, in order to separate the crushed material into the small diameter powder granules, the medium diameter powder granules and the large diameter powder granules, as described above, a sieve having a predetermined mesh size can be used.

Here, an example has been described in which the crushed material is divided into three types: small-diameter powder particles, medium-diameter powder particles, and large-diameter powder particles. For example, small-diameter powder particles, medium-diameter powder particles, and large particles are described. At least one of the powder or granular materials may be further classified according to the size of the particle size, and may be divided into four or more types. In this case, a small-diameter powder or granular material having a relatively small particle size, a large-diameter powder or granular material having a relatively large particle size, or a medium-diameter material whose particle size is intermediate between the small-diameter powder or granular material and the large-diameter powder or granular material. The above-mentioned predetermined treatment can be applied to each of the powder or granular materials that can be regarded as the powder or granular material.

(Re-crushing sieve separate process)
In the re-crushing and sieving step, the medium-diameter powder or granular material is further crushed, and the re-crushed product obtained thereby is sieved to a predetermined particle size. Then, for each of the plurality of types of powders and granules obtained by the re-crushing and sieving, a recovery step, a copper smelting step, and in some cases, a further re-crushing and sieving step can be performed. Impurities such as copper can be effectively removed, and the recovery rate of valuable metals such as cobalt can be effectively increased.

In the crushing of the re-crushing sieve separate step, the same crusher as the above-mentioned crushing step can be used. Then, it is preferable to obtain a re-crushed product in which the powder or granular material having a particle size larger than 1 mm accounts for more than 26.3% of the total powder or granular material by this crushing, as in the crushing step.
However, it is also possible to use a crusher different from the crushing step in the re-crushing and sieving step.

In the sieving of the re-crushing sieving step, the above-mentioned re-crushed material is divided into at least small-diameter powders having a relatively small particle size and large-diameter powders having a relatively large particle size, as in the sieving step. It is preferable to divide the body into a medium-diameter powder or granular material having a particle size intermediate between the small-diameter powder or granular material and the large-diameter powder or granular material. Therefore, here, the same sieve as in the sieve separation step can be used.
In particular, the small-diameter powder or granular material has a particle size of 1 mm or less, the medium-diameter powder or granular material has a particle size of more than 1 mm and 3.35 mm or less, and the large-diameter powder or granular material has a particle size of 3.35 mm or less. Is preferably larger than 3.35 mm.

In this case, among the powder or granular materials obtained here, the small-diameter powder or granular material can be sent to the recovery step, and the large-diameter powder or granular material can be sent to the copper smelting process. For medium-diameter powders and granules, it is preferable to perform the re-crushing and sieving step again from the viewpoint of improving the recovery rate of valuable metals and removing impurities. That is, by repeating the re-crushing and sieving step for the medium-diameter powders and granules, the recovery rate of cobalt and the like is further significantly improved, and copper and the like are removed even more effectively.

On the other hand, even if the number of re-crushing and sieving steps is increased too much, the effect is not expected so much despite the increase in work man-hours and time. Therefore, when the above-mentioned crushing step and sieving step are counted as the first crushing and sieving, and the re-crushing sieving step is counted as the second and subsequent crushing and sieving, the number of times of the crushing and sieving is twice. It is preferably more than 10 times and less than 10 times. More preferably, the number of repetitions of the re-crushing and sieving step is 5 or more and 8 or less. The powder or granular material classified as the medium-diameter powder or granular material in the final re-crushing and sieving step can be sent to the copper smelting process in the same manner as the large-diameter powder or granular material.

(Recovery process)
A recovery step can be performed on the small-diameter powders and granules obtained as described above, and in this recovery step, a predetermined method for recovering at least one selected from cobalt, nickel and manganese from the small-diameter powders and granules. Is processed.
Here, various treatments for recovering the metal can be adopted, and as an example thereof, for example, battery powder containing small-diameter powders and granules is added to the leachate to leach it, and the liquid after leaching is used. On the other hand, solvent extraction or neutralization in a plurality of steps can be performed, and the solution obtained in each step can be back-extracted, electrolyzed, carbonized or the like.

Next, the method for treating lithium ion battery waste of the present invention was carried out on a trial basis, and its effect was confirmed, which will be described below. However, the description here is for the sole purpose and is not intended to be limited thereto.

(Comparative example)
As shown in FIG. 2, the lithium ion battery roasting residue obtained by roasting the lithium ion battery waste is crushed using a twin-screw rotor rotary crusher and a sieve having a mesh size of 1 mm. The sieves used were sequentially subjected to sieving to obtain small-diameter powders having a particle size of 1 mm or less and large-diameter powders having a particle size larger than 1 mm. The grades of each metal in the small-diameter powder particles and the large-diameter powder particles are as shown in FIG.

(Invention Example)
As shown in FIG. 3, the same lithium ion battery roasting residue as in the comparative example was crushed using a twin-screw rotor rotary crusher and a sieve using sieves having a mesh size of 1 mm and 3.35 mm. Separately, small-diameter powders having a particle size of 1 mm or less, medium-diameter powders having a particle size larger than 1 mm and 3.35 mm or less, and large-diameter powders having a particle size larger than 3.35 mm. Granules were obtained. The grades of each metal in the small-diameter powder granules, the medium-diameter powder granules, and the large-diameter powder granules are as shown in FIG.

Of these, the medium-diameter powder or granular material is repeatedly crushed and sieved in the same order, and each time the number of times of crushing is repeated, the small-diameter powder or granular material, the medium-diameter powder or granular material, and the large-diameter powder or granular material are repeatedly crushed and sieved. The weight and Co and Cu grades were measured. The results are shown graphically in FIGS. 4 and 5. In addition, the cumulative distribution rate in FIG. 4 means the weight percentage in which the samples sieved after crushing the previous medium-diameter powder or granular material after the number of crushing times is 2 times, and the cumulative processing amount in FIG. The ratio means a weight ratio in which the amount of the first crushed material is set to 1 and the weights of the repeated medium-diameter powders and granules are piled up.

From the results shown in FIGS. Since it is reduced to%, it can be seen that the increase in the load in the subsequent recovery process can be effectively suppressed.
Therefore, in this example, it was found that the Co production amount could be improved by 42.7%.

Claims (6)

Lithium-ion battery A method of crushing waste and sieving it for disposal.
A crushing step of crushing lithium-ion battery waste using a crusher to obtain crushed material containing powder or granular material and having a powder or granular material having a particle size larger than 1 mm accounting for more than 26.3% of the total powder or granular material. ,
The crushed material is sieved, and the crushed material is divided into at least a small-diameter powder or granular material having a relatively small particle size, a large-diameter powder or granular material having a relatively large particle size, and the small-diameter powder or granular material having a relatively large particle size. And a sieving step of separating the medium-diameter powder or granular material into the medium-diameter powder or granular material, which is intermediate between the large-diameter powder or granular material, and
After obtaining the re-crushed material by crushing the in径粉granules, see contains a re-crushing sieving step of sieving the re crushed,
In the re-crushing and sieving step, the re-crushed material is at least a small-diameter powder or granular material having a relatively small particle size, a large-diameter powder or granular material having a relatively large particle size, and a small-diameter powder or granular material having a relatively large particle size. Divide into medium-diameter powder and granules, which are intermediate between the body and the large-diameter powder and granules.
A method for treating lithium ion battery waste , wherein the re-crushing and sieving step is repeated. The crushing step and sieving step was first crushing and sieving, the crushing and sieving the second or subsequent repetition of the re-crushing sieve step, the crushing and the number another sieve, 5 times or more and 10 times hereinafter to processing method of a lithium ion battery waste according to claim 1. The small-diameter powder or granular material has a particle size of 1 mm or less, the medium-diameter powder or granular material has a particle size of more than 1 mm and 3.35 mm or less, and the large-diameter powder or granular material has a grain size of 3.35 mm or less. The method for treating lithium ion battery waste according to claim 1 or 2 , wherein the diameter is larger than 3.35 mm. The method for treating lithium ion battery waste according to any one of claims 1 to 3 , wherein the small-diameter powder or granular material is sent to a recovery step for recovering at least one of cobalt, nickel and manganese. The method for treating lithium ion battery waste according to any one of claims 1 to 4 , wherein the large-diameter powder or granular material is sent to a copper smelting step. In the re-crushing and sieving step, the medium-diameter powder or granular material is crushed using a crusher.
Said crusher used in the crushing step and the re-crushing sieve step, clearance and a is single or twin screw rotors rotary crusher 15 mm to 20 mm, according to any one of claims 1 to 5 Lithium-ion battery waste disposal method.

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