JP2018170223A - Processing method of lithium ion battery scrap - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a processing method of lithium ion battery scrap, capable of achieving effective utilization of resources furthermore by recovering metal from sifted upper materials that remain on a sifter when crushed materials obtained by crushing lithium ion battery scrap are sifted.SOLUTION: A processing method of lithium ion battery scrap of the present invention includes: a crushing step of crushing lithium ion battery scrap; a sifting step of sifting crushed materials obtained in the crushing step; and a wet peeling step of, with respect to sifted upper materials that remain on a sifter in the sifting step, peeling metal powder from the sifted upper materials using a liquid to be separated and obtaining metal powder and a solution after separation.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for processing lithium ion battery scrap, and in particular, proposes a technique capable of improving the recovery rate of a predetermined metal from lithium ion battery scrap and further utilizing resources effectively. Is.

Lithium ion batteries used in various 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 and a negative electrode material containing the positive electrode active material In recent years, with the increase in the amount of use and the expansion of the range of use, the amount discarded due to defects in the product life of the battery and the manufacturing process has increased. Is in a situation.
Under such circumstances, it is desirable to easily recover valuable metals such as nickel and cobalt from lithium ion battery scrap that is discarded in large quantities at a relatively low cost for reuse.

To dispose of discarded lithium-ion battery scraps for the recovery of valuable metals, first, the lithium-ion battery scraps are roasted to remove harmful electrolytes contained therein and render them harmless. A roasting step and subsequent crushing and sieving are sequentially performed, and a crushing and sieving step for removing aluminum contained in the casing and the positive electrode substrate to some extent is performed.
Next, the powdered battery powder obtained under the sieving and sieving step is added to the leaching solution and leached, and lithium, nickel, cobalt, manganese, copper, aluminum, and the like that can be contained therein are dissolved in the solution. Perform leaching process.

  And after that, the collection | recovery process which isolate | separates each metal element melt | dissolved in the post-leaching liquid obtained at the leaching process is performed. Here, in order to separate each metal leached in the liquid after leaching, the liquid after leaching is sequentially subjected to multiple stages of solvent extraction or neutralization, etc. according to the metal to be separated. Back extraction, electrolysis, carbonation, and other treatments are performed on each solution obtained in (1). Specifically, each valuable metal can be recovered by first recovering aluminum, subsequently recovering manganese and copper, then cobalt, then nickel, and finally leaving lithium in the aqueous phase.

By the way, in this type of metal recovery technology, the amount of aluminum that can be contained in the battery powder under sieving by sieving as described above is reduced as much as possible, and the recovery target metal such as an active material remains on the sieving so as not to be lost. Although importance is placed on conditions such as crushing, sieving and other aluminum removal treatments, and improvements are being considered, many of them require complex equipment or processes, requiring significant investment.
On the other hand, a certain amount of metal to be collected is often contained on the sieve, and it is desirable from the viewpoint of further effective use of resources to collect the metal from the sieve.

  The present invention has been made paying attention to such points, and the object thereof is to remain on the sieve when the crushed material obtained by crushing lithium ion battery scrap is sieved. An object of the present invention is to provide a method for treating lithium ion battery scrap, which can recover metal from the sieve top and further effectively use resources.

  The inventor screened the crushed material of the lithium ion battery scrap, and as a result of earnestly examining the state of the metal to be collected that can be contained in the on-screen material remaining on the screen, as a result of processing the on-screen material using a liquid, It has been found that it is effective to perform a wet stripping process for stripping metal powder from the sieve top.

  Under such knowledge, the processing method of the lithium ion battery scrap of the present invention is a method of processing lithium ion battery scrap, a crushing process for crushing lithium ion battery scrap, and a crushed material obtained in the crushing process The sieving step for sieving, and the sieved product remaining on the sieve in the sieving step are separated by separating the metal powder from the sieved product using a liquid, and the metal powder and the separated liquid are separated. A wet stripping step to obtain.

  In the wet stripping step, it is preferable that the sieved product is put into the liquid, and the metal powder is stripped from the sieved product in the liquid and separated.

  The pH of the post-separation solution obtained in the wet stripping process is preferably 7-10.

  The above-described lithium ion battery scrap processing method preferably further includes a lithium recovery step of recovering lithium from the post-separation liquid obtained in the wet stripping step.

  In the lithium ion battery scrap treatment method described above, it is preferable to recover at least one metal selected from the group consisting of cobalt, nickel and manganese from the metal powder obtained in the wet stripping process.

  In the wet stripping process, after the metal powder is stripped from the sieve top, the metal containing copper and / or aluminum is recovered from the sieve top separated by the strainer before the metal powder and the separated liquid are separated. It is preferable.

  According to the lithium ion battery scrap processing method of the present invention, the wet sieve process is performed in which the sieved material remaining on the sieve in the sieving process is treated in the liquid to separate the metal powder from the sieved product. As a result, the metal can be recovered from the sieved product remaining on the sieve, so that further effective utilization of resources can be achieved.

It is a flowchart which shows the processing method of the lithium ion battery scrap which concerns on one Embodiment of this invention. It is a flowchart which shows the test of an Example.

Hereinafter, embodiments of the present invention will be described in detail.
The lithium ion battery scrap processing method according to one embodiment of the present invention includes, as illustrated in FIG. 1, a roasting step of heating and roasting lithium ion battery scrap, and crushing of lithium ion battery scrap. Step, sieving step of sieving the crushed material obtained in the crushing step, and putting the sieved material remaining on the sieve in the sieving step into the liquid, and removing the metal powder from the sieved product in the liquid A wet peeling step of peeling and obtaining a metal powder and a liquid after separation by solid-liquid separation.

(Lithium ion battery scrap)
The lithium-ion battery scraps targeted by the present invention are wastes of lithium-ion batteries 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 a battery product, manufacturing defects, or other reasons, etc., and to effectively utilize resources by targeting such lithium ion battery scrap. Can do.

  The lithium ion battery scrap can be a so-called battery case, which may be a mixture of a positive electrode material with an aluminum foil or a positive electrode active material, and the battery case is roasted as necessary. It can be chemically treated, crushed, and / or sieved.

  In addition to a positive electrode active material that is a lithium metal salt containing manganese, nickel, and cobalt, a negative electrode material containing carbon, iron, and copper, and a positive electrode active material include, for example, polyvinylidene fluoride (PVDF) and other organic materials. An aluminum foil (positive electrode base material) applied and fixed by a binder or the like, and a casing containing aluminum as an exterior that wraps around the lithium ion battery may be included. Specifically, the lithium ion battery includes a single metal oxide composed of one element of lithium, nickel, cobalt, and manganese constituting the positive electrode active material and / or a composite metal oxide composed of two or more elements. As well as aluminum, copper, iron, carbon and the like.

  The lithium-ion battery scrap wrapped in the housing can have a substantially square or rectangular planar outline shape. In this case, as dimensions before processing, for example, the vertical dimension is 40 mm to 80 mm, and the horizontal dimension. Of 35 mm to 65 mm and a thickness of 4 mm to 5 mm can be targeted.

(Roasting process)
In the roasting step, the above-described lithium ion battery scrap is roasted. This roasting process raises the temperature of the lithium ion battery scrap, removes the internal electrolyte and renders it harmless, and generally decomposes the binder that binds the aluminum foil and the positive electrode active material. Accelerates separation of aluminum foil and positive electrode active material during crushing and sieving to increase the recovery rate of positive electrode active material recovered under the sieve, and further leach out valuable metals contained in lithium ion battery scrap It is performed for the purpose of changing to a form that can be easily leached in the process.
However, here, it is intended to recover valuable metals contained in the positive electrode active material, etc., from the material on the sieve remaining on the sieve, so the aim was to improve the recovery rate of the positive electrode active material under the sieve Excessive capital investment in the roasting process is not always necessary.

In the roasting process, the lithium ion battery scrap 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) is decomposed, and a large amount of cobalt can be made into a form of cobalt oxide (CoO) or simple substance cobalt that is liable to acid leaching. On the other hand, if the temperature at this time is too high, the aluminum having a melting point of 660 ° C. melts, so that the temperature is, for example, about 450 ° C. to 650 ° C. as measured by the surface temperature of the lithium ion battery scrap housing. The temperature can be maintained for about 20 minutes to 120 minutes.

(Crushing process)
Next, a crushing step is performed mainly for destroying the case of the lithium ion battery scrap roasted as described above and selectively separating the positive electrode active material from the aluminum foil coated with the positive electrode active material. Thereby, a lithium ion battery scrap is crushed and a crushed material is obtained.

  Here, various known apparatuses or devices can be used. In particular, it is preferable to use an impact-type pulverizer that can crush lithium ion battery scrap while applying an impact while cutting. Examples of the impact type pulverizer include a sample mill, a hammer mill, a pin mill, a wing mill, a tornado mill, and a hammark crusher. Note that a screen can be installed at the exit of the pulverizer, whereby the lithium ion battery scrap is discharged from the pulverizer through the screen when pulverized to a size that can pass through the screen.

(Sieving process)
After the crushing step, a sieving step of sieving the crushed material using a sieve with an appropriate opening is performed. Accordingly, generally, there are many fine powdery positive electrode active materials separated from aluminum in the above crushing step under the sieve, and on the other hand, larger granular aluminum foil and Copper foil remains.

In the sieving step, generally, the opening of the sieving used for sieving is set so that the aluminum quality contained in the under sieve is 10% by mass or less. More typically, the aluminum quality in the under sieve may be 6% by mass or less. In addition, the conditions are comprehensively controlled in combination with the above-described roasting step and crushing step so as to increase the cobalt recovery rate and achieve the aluminum quality of such a sieved product.
Specifically, for example, sieving can be performed with a sieve having an opening of 1 to 4 mm, typically 1 to 2 mm. Thereby, the amount of aluminum and iron in the under sieve is reduced, and the treatment of the under sieve is improved.

  However, even if the opening of the sieve is set as described above, it cannot be denied that the metal to be recovered is included in the sieved object to some extent, and the following steps are carried out in order to recover the metal from the sieved object. To do. Even if the sieve top contains a very small amount of the metal to be collected, it is effective to apply the present invention and is not limited to the above-described conditions.

(Wet peeling process)
Valuable metals such as positive electrode active materials that were not separated in the crushing process are adhered to the aluminum foil and copper foil remaining as the sieve product in the sieving process. In order to recover a predetermined metal, the wet stripping process is performed on the sieved product.
If the lithium ion battery scrap has a ternary positive electrode material, for example, 10% to 50% by mass of cobalt, 5% to 20% by mass of nickel, 0.1 mass%-5 mass%, 0.1 mass%-5 mass% of lithium, 10 mass%-50 mass% of aluminum, and 10 mass%-30 mass% of copper may be contained.

  In the wet peeling process, the metal adhering to the aluminum foil or copper foil of the sieve top is peeled off using a predetermined liquid such as water or an acidic aqueous solution. Since the aqueous solution after washing the under sieve becomes alkaline due to the dissolution of lithium, the liquid is preferably water or an acidic aqueous solution so that the pH of the liquid after separation is 7 to 10 as described later. For adjustment, an acid may be added to the aqueous solution after the wet peeling step. Here, the liquid is used to separate the metal powder from the aluminum foil or the like based on the force acting on the metal powder on the foil by the liquid.

For example, a sieve is put into a tank in which liquid is stored, and the liquid water flow or collision between sieves in the liquid occurs, for example, by stirring or shaking by rotating blades or drums in the tank. By the action of force on the metal powder on the foil due to the above, the metal adhering to the aluminum foil or the like on the sieve can be peeled off. The liquid may be stirred or shaken using ultrasonic waves. Or a liquid can be sprayed with respect to a sieve top thing, and the metal powder on foil can also be peeled based on the impact force. In any case, the liquid and the sieved product can be mixed by using the liquid. As long as the screened product and the liquid come into contact with each other with a relatively large force, specific modes such as jetting and stirring are not limited.
And after that, solid-liquid separation can be performed to separate the metal powder and the separated liquid and obtain them respectively.

  As a result, metal powder containing valuable metals such as positive electrode active material remaining on the sieve in the sieving step can be effectively separated from aluminum foil and the like, so that the recovery rate of valuable metals from lithium ion battery scrap can be increased. This is advantageous from the viewpoint of recycling. In addition, various methods have been proposed so far that valuable metals are not left on the sieve so as to reduce loss, but in the present invention, the facilities and processes required for such a method are complicated, The recovery rate can be improved by a simple process without requiring a large investment.

In addition, here, wet peeling using a liquid makes it difficult for dusts such as nickel, cobalt, and manganese, which are specific chemical substances, to occur, which is also effective from the viewpoint of safety and health.
Furthermore, the wet treatment has an advantage that lithium that may be contained in the sieved product is dissolved in the liquid and lithium can be recovered in the solution, as will be described later.

  When stirring or shaking the liquid charged with the sieved product, the liquid and the sieved product can be mixed effectively, and the force of stirring or the like can be used. The positive electrode active material can be effectively peeled off from aluminum foil or the like. However, it should be noted that if the aluminum foil or copper foil is finely pulverized by this stirring or the like, the copper or aluminum quality in the obtained metal powder increases.

After the metal powder is sufficiently peeled from the sieve top in the liquid by such stirring, etc., the liquid is filtered with a strainer, and from the sieve top of the strainer, of the copper and aluminum contained therein It is preferable to collect a metal containing at least one kind, for example, a copper foil such as a copper foil or an aluminum foil, or an aluminum foil.
The strainer used here may be a sieve having metal powder under the sieve and copper foil or aluminum foil etc. on the sieve. For example, the strainer may be the same as the sieve in the first sieving step. Is preferable.

Thereafter, solid-liquid separation is performed using a known apparatus and method such as a filter press or thickener to separate the metal powder from the separated liquid. Thereby, copper and aluminum are sufficiently removed from the metal powder, and lithium is also dissolved in the liquid and removed.
When the case where the lithium ion battery scrap has a ternary positive electrode material is described as an example, this metal powder includes, for example, 5 mass% to 30 mass% of cobalt and 5 mass% to 30 mass% of nickel. Manganese is contained in an amount of 5 to 30% by mass, lithium is contained in an amount of 1 to 15% by mass, aluminum is contained in an amount of 1 to 30% by mass, and copper is contained in an amount of 1 to 30% by mass.

(Lithium recovery process)
The liquid after separation may be a lithium-dissolved solution due to the dissolution of lithium that can be contained in the sieved product in the liquid by the treatment as described above in the wet peeling step. In this case, it is preferable to recover lithium from the separated solution. The lithium concentration in the separated liquid may be, for example, 0.5 g / L to 10 g / L.

  The pH of the liquid after separation is preferably 7-10. If the pH is too low, impurities such as heavy metals including Co and Ni and Al will elute in the Li leaching solution, and if the pH is too high, Al will elute in the Li leaching solution. Therefore, more preferably, the pH of the post-separation solution is 8-9.

  Lithium can be recovered from the liquid after separation by various known techniques. For example, lithium can be carbonated by adding carbonate or blowing carbon dioxide, and recovered as lithium carbonate. Can do.

(Processing under sieve)
The under sieve is treated by a general method, and valuable metals such as cobalt, nickel and manganese can be recovered therefrom.
As an example, the sieving material is added to the leaching solution and leached, the solution after leaching is subjected to multiple stages of solvent extraction or neutralization, and the solution obtained in each stage is back-extracted. Electrolysis, carbonation, etc. can be performed.

  Next, the present invention was experimentally implemented and its effects were confirmed and will be described below. However, the description here is for illustrative purposes only and is not intended to be limiting.

As shown in FIG. 2, 125 g of sieved material was put into 500 mL of water and shaken in a 1000 mL container. Since the pH was 11.5 in this state, sulfuric acid was added to adjust the pH to 8 Adjusted to .1. On the other hand, primary filtration was performed with a sieve having an opening of 850 μm as a strainer. The resulting slurry was subjected to secondary filtration by filtering with 5 types A filter paper to obtain a metal powder and a filtrate.
Table 1 shows the quality of the metal powder, and Table 2 shows the concentration of each substance in the filtrate.

  From the above results, it can be seen that valuable metals can be effectively recovered from the sieve top. Therefore, according to the present invention, it has been found that further effective utilization of resources can be achieved.

Claims (6)

  A method for treating lithium ion battery scrap, a crushing process for crushing lithium ion battery scrap, a sieving process for sieving crushed material obtained in the crushing process, and a sieve remaining on the sieve in the sieving process A method for treating lithium ion battery scrap, comprising: a wet stripping step of separating a metal powder from the above sieved product by separating the metal powder from the top product using a liquid, and obtaining a metal powder and a liquid after separation.   The processing method of the lithium ion battery scrap of Claim 1 which makes pH of the post-separation liquid obtained at a wet peeling process 7-10.   The processing method of the lithium ion battery scrap of Claim 1 or 2 which throws the said sieve top into the said liquid at the said wet peeling process, and peels and isolate | separates metal powder from the said sieve top in this liquid. .   The processing method of the lithium ion battery scrap as described in any one of Claims 1-3 which further has a lithium collection | recovery process which collect | recovers lithium from the post-separation liquid obtained at a wet peeling process.   The processing method of the lithium ion battery scrap as described in any one of Claims 1-4 which collect | recovers at least 1 type of metal selected from the group which consists of cobalt, nickel, and manganese from the metal powder obtained by a wet peeling process. .   After the metal powder is peeled from the sieved product in the wet peeling process, the metal containing copper and / or aluminum is recovered from the sieved product separated by the strainer before separating the metal powder and the separated liquid. The processing method of the lithium ion battery scrap as described in any one of Claims 1-5.

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