JP6571123B2 - Method for leaching lithium ion battery scrap and method for recovering metal from lithium ion battery scrap - Google Patents

Description

  The present invention relates to a method for leaching lithium ion battery scrap and a method for recovering metal from lithium ion battery scrap using the same, and in particular, a technique that can contribute to improvement in processing efficiency and cost reduction. It is what we propose.

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.

  As described above, in order to separate and recover each metal from the post-leaching solution obtained by leaching lithium ion battery scrap, many processes are required. Therefore, if the specific metal contained in the battery powder can be separated and removed in advance as a solid without dissolving in the leachate, it is applied to the post-leaching solution in order to separate and recover each metal in the subsequent recovery step. Among various processes, the process necessary for recovering the removed specific metal can be simplified or omitted, which is effective from the viewpoint of the efficiency and cost of the process.

  In this regard, Patent Document 1 states that “a method of removing copper from a lithium ion battery scrap containing copper, wherein the lithium ion battery scrap is added to an acidic solution, and an aluminum solid is contained in the acidic solution. Lithium ion battery comprising: a leaching step for leaching the lithium ion battery scrap under existing conditions; and a copper separation step for separating copper contained as a solid in the acidic solution from the acidic solution after the leaching step A method for removing copper from scrap has been proposed. And according to this method, “in the leaching step, the leaching rate of copper can be kept sufficiently small, so that the copper contained as a solid in the acidic solution can be separated effectively and easily in the subsequent copper separation step. As a result, it is possible to contribute to an improvement in processing efficiency and cost reduction in subsequent steps. "

JP-A-2006-191134

By the way, when the lithium ion battery scrap is not roasted, most of the cobalt can be contained in the battery powder as lithium cobaltate (LiCoO ₂ ). Then, when acid leaching of such non-roasted battery powder, a large amount of lithium cobaltate is present in the acidic solution, and aluminum, which is a base metal than copper, is present as a solid in the acidic solution. Even so, the oxidation-reduction potential (ORP value) of the acidic solution during leaching increases. As a result, there is a problem that copper is dissolved and copper leaching cannot be sufficiently suppressed.
Therefore, the proposed technique described in Patent Document 1 described above has room for further improvement in terms of improvement in processing efficiency and cost reduction by suppressing copper leaching.

  The object of the present invention is to solve such a problem. The purpose of the present invention is to make most of the copper into a solid state by leaching the lithium ion battery scrap into Providing a method for leaching lithium ion battery scrap and a method for recovering metal from lithium ion battery scrap that can improve the processing efficiency and reduce the cost by simplifying or omitting the processing required to remove the dissolved copper There is to do.

  As a result of earnestly examining the method of preventing the copper contained in the non-roasted battery powder from being leached in acid leaching of the non-roasted battery powder that is not substantially subjected to the roasting treatment, the inventor It was newly found that the leaching of copper contained in the battery powder can be effectively suppressed by bringing the battery into contact with the acid leaching solution together with the roasted battery powder subjected to the roasting treatment under a predetermined condition. This is because battery powder that has been subjected to a predetermined roasting treatment decomposes the oxide of the predetermined metal to convert many metals into a single metal, and when leached, the standard oxidation-reduction potential is lower than that of copper. It is considered that the base metal alone suppresses the increase of the oxidation-reduction potential, thereby suppressing the elution of copper or the precipitation of copper, but is not limited to such a theory.

  Based on such knowledge, the lithium ion battery scrap leaching method of the present invention is a method of leaching lithium ion battery scrap as powdered battery powder, and roasting non-roasted battery powder containing at least copper The battery powder is leached by contact with an acidic leaching solution.

Here, the term “roasted battery powder” means battery powder that has been substantially roasted after being subjected to roasting treatment at a temperature of 450 ° C. or higher, and in particular, maintained at a temperature of 450 ° C. or higher for 20 minutes or longer. Battery powder that has been subjected to roasting treatment can be obtained.
On the other hand, the “non-roasted battery powder” means a battery powder that is not subjected to the roasting treatment as described above and can be regarded as not substantially roasted. That is, “non-roasted battery powder” is battery powder that has not been roasted at all and / or battery powder that has been roasted to maintain at a temperature of less than 450 ° C. for less than 20 minutes. Can do.

  In the lithium ion battery scrap leaching method of the present invention, it is preferable that the roasted battery powder contains at least one elemental metal selected from the group consisting of cobalt, nickel and manganese.

  In the lithium ion battery scrap leaching method according to the present invention, it is preferable that the roasted battery powder contains a single metal of iron and / or aluminum.

  In the method for leaching lithium ion battery scrap of the present invention, non-roasted battery powder and roasted in contact with the acid leaching solution so that the oxidation reduction potential (silver / silver chloride potential reference) of the acid leaching solution during leaching is 0 mV or less. It is preferable to adjust the amount of battery powder.

  The method for recovering metal from lithium ion battery scrap of the present invention is a leaching solution obtained by leaching non-roasted battery powder and roasted battery powder using any of the above-described leaching methods of lithium ion battery scrap. And recovering the metal contained in the liquid after leaching.

  According to this invention, the non-roasted battery powder containing at least copper is leached together with the roasted battery powder in contact with the acidic leaching solution, so that the oxidation-reduction potential (ORP value) at the time of leaching is suppressed to a low level. Can be effectively suppressed. As a result, it is possible to simplify or omit the process required to remove the copper dissolved in the liquid after leaching, thereby improving the processing efficiency and reducing the cost.

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

Hereinafter, embodiments of the present invention will be described in detail.
A method for leaching lithium ion battery scrap according to one embodiment of the present invention is a method for leaching lithium ion battery scrap as powdered battery powder, and a non-roasted battery powder containing at least copper is roasted battery Leach together with the powder in contact with acidic leachate.
For example, the method of the embodiment of the present invention can be carried out through various steps according to the flow illustrated in FIG.

(Lithium ion battery scrap)
The lithium ion battery scrap targeted by the present invention is a lithium ion battery waste that can be used in various electronic devices such as mobile phones. More specifically, the battery product has been discarded due to the life of the battery product, manufacturing failure, or other reasons, and effective use of resources can be achieved by targeting such lithium ion battery scrap.

Here, the lithium ion battery scrap contains copper as the negative electrode current collector. If the copper contained in the lithium-ion battery scrap dissolves in the leachate after calcination after calcination or after crushing and sieving as described later, a process for separating it from the liquor after leaching is required, which increases the processing efficiency. Reduce costs and increase costs.
Therefore, when processing lithium ion battery scrap, it is effective to remove copper as described above easily and reliably using the method according to the embodiment of the present invention. Lithium ion battery scraps typically contain 8% to 20% by weight of copper.

  Moreover, the lithium ion battery scrap may have a housing containing aluminum as an exterior that wraps around the lithium ion battery scrap. Examples of the housing include those made only of aluminum and those containing aluminum, iron, aluminum laminate, and the like. In the present invention, the lithium ion battery scrap preferably contains such aluminum in order to suppress copper leaching.

In addition, the lithium ion battery scrap includes a positive electrode active material composed of one or more single metal oxides of lithium, nickel, cobalt, and manganese, or two or more composite metal oxides, and a positive electrode. In general, the active material includes an aluminum foil (positive electrode base material) that is applied and fixed with, for example, polyvinylidene fluoride (PVDF) or other organic binder. In addition, the lithium ion battery scrap may contain iron or the like.
Moreover, in general, lithium ion battery scrap includes an electrolyte in a housing. For example, ethylene carbonate, diethyl carbonate, or the like may be used as the electrolytic solution.

  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, but not limited to this size.

(Roasting process)
As shown in FIG. 1, the roasted battery powder added to the acidic leachate in the leaching step is subjected to a predetermined roasting process through the roasting step. On the other hand, as shown in the figure, the non-roasted battery powder is substantially not subjected to the roasting process without being subjected to the roasting process and / or subjected to the roasting process but not subjected to the predetermined roasting process. It was not roasted.

  When obtaining the roasted battery powder, a predetermined roasting process is performed on the lithium ion battery scrap in the roasting step. This roasting process raises the temperature of the lithium-ion battery scrap, removes the internal electrolyte, renders it harmless, decomposes the binder that binds the aluminum foil and the positive electrode active material, crushes and sifts Accelerate the separation of the aluminum foil and the positive electrode active material at the time to increase the recovery rate of the positive electrode active material recovered under the sieve, and further leach the valuable metals contained in the lithium ion battery scrap in the leaching process described later This is done for the purpose of changing to a form that is easy to make.

In the roasting step for obtaining the roasted battery powder, the lithium ion battery scrap is 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 be acid leached. Nickel can be converted to simple nickel from LiNiO ₂ and manganese can be converted to simple manganese from LiMnO ₂ and LiMn ₂ O ₄ .
On the other hand, when the temperature at this time is too high, aluminum having a melting point of 660 ° C. is melted, so the temperature is preferably within the range of 450 ° C. to 650 ° C.

When the temperature in the baking process for obtaining the roasted battery powder is less than 450 ° C., the electrolytic solution is not sufficiently removed and the binder is not sufficiently decomposed, and aluminum is effectively used in the crushing and sieving process described later. Cannot be separated. In this case, the change to a single metal such as cobalt is not sufficiently promoted, and there is a concern that cobalt or the like does not dissolve in the subsequent leaching step. In this case, it is considered that the copper leaching suppression effect in the non-roasted battery powder by the roasted battery powder in the leaching step cannot be sufficiently obtained.
In addition, when the temperature is increased to over 650 ° C., the oxidation and embrittlement of the aluminum progresses, and the aluminum is easily crushed in the crushing and sieving process, and the amount of aluminum that moves under the sieving together with the positive electrode active material component This increases the work and costs in later collection steps.

From such a viewpoint, the temperature in the roasting treatment for obtaining the roasted battery powder is more preferably 450 ° C. to 550 ° C., and further preferably 450 ° C. to 500 ° C.
This temperature can be measured by measuring the surface temperature of the casing of the lithium ion battery scrap.

  The time for maintaining the temperature within the temperature range in the roasting treatment for obtaining the roasted battery powder is preferably 20 minutes to 120 minutes. If it is less than 20 minutes, there is a possibility that the removal of the electrolytic solution, the decomposition of the binder, or the change to a single metal may not be sufficient, and if it is longer than 120 minutes, the oxidation and embrittlement of aluminum tends to be promoted. Another reason is that the heating cost increases. More preferably, it is 20 minutes-90 minutes, More preferably, it is 20 minutes-60 minutes.

On the other hand, the non-roasted battery powder includes one obtained by heating lithium ion battery scrap at a temperature of less than 450 ° C., typically 400 ° C. or less, for example, for a time of less than 20 minutes in the roasting step. In other words, the non-roasted battery powder is not subjected to the above-described roasting treatment for decomposing the lithium metal salt of the positive electrode active material such as the roasted battery powder, but is subjected to a milder roasting treatment. Is included. In this case, LiCoO ₂ or the like of the positive electrode active material does not change to a form of cobalt oxide (CoO) or simple substance cobalt, and LiCoO ₂ or the like remains as in the case where no roasting treatment is performed.
However, in the embodiment of the present invention, as will be described in detail later, even when such non-roasted battery powder containing LiCoO ₂ or the like is leached together with the roasted battery powder, the oxidation-reduction potential is increased. Therefore, copper leaching can be effectively suppressed.

  A roasting process can be performed using various heating equipments, such as a rotary kiln furnace and other various furnaces. If the temperature of the lithium ion battery scrap can be controlled as described above, a furnace for heating in an air atmosphere can be used. Therefore, the processing method of the present invention is advantageous in that it can be carried out without using special equipment for roasting lithium ion battery scrap.

(Crushing and sieving process)
When obtaining roasted battery powder or non-roasted battery powder that is not substantially roasted, it is roasted against lithium ion battery scrap that has been roasted through the above roasting process or not at all. In order to obtain non-roasted battery powder that has not been roasted, the lithium ion battery scrap that has not been roasted is crushed to remove the positive electrode material and the negative electrode material from the housing, and aluminum powder that can be contained therein And sieving with a predetermined sieve for removing. Thereby, for example, aluminum or copper remains on the sieve, and battery powder from which aluminum or copper has been removed to some extent can be obtained below the sieve.

Lithium ion battery scrap is mainly crushed to destroy the casing of the lithium ion battery scrap and to selectively separate the positive electrode active material from the aluminum foil coated with the positive electrode active material.
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.

  The lithium ion battery scrap after crushing is sieved using a sieve having an appropriate opening. Thus, the battery powder obtained under the sieve contains a large amount of fine powdery positive electrode active material separated from aluminum by the above-mentioned crushing, and larger granular aluminum is removed to some extent.

After the crushing / sieving step, roasted battery powder and non-roasted battery powder can be obtained.
Here, the roasted battery powder contains at least one kind of single metal (metal) selected from the group consisting of cobalt, nickel, and manganese by performing a predetermined roasting process in the roasting step described above. Is preferred. The total content of these single metals is preferably 0.5 to 10% by mass, more preferably 1 to 5% by mass. Thereby, the leaching of copper contained in the non-roasted battery powder can be effectively suppressed in the later-described leaching step. On the other hand, if the amount of a single metal such as cobalt is too large, there are problems that the leaching rate of cobalt deteriorates and the leaching time of cobalt becomes long. For this reason, it is preferable that the content of the single metal is not more than the above upper limit value.

The roasted battery powder has a lithium oxide content such as LiCoO ₂ constituting the positive electrode active material of 10% by mass or less. This is because many of the metal oxides were decomposed into single metals by being sufficiently roasted.
Moreover, the roasted battery powder may contain simple metals such as iron and aluminum. Such a simple metal of iron and aluminum is also desirable in that it works to suppress copper leaching in the leaching step, but if a large amount of iron or aluminum is contained, it takes time and effort to separate these metals in the subsequent step. Therefore, the total content of simple metals of iron and aluminum is preferably 0.5% by mass to 10% by mass.

On the other hand, the non-roasted battery powder is not substantially roasted so that the lithium oxide is hardly decomposed. Specifically, it contains lithium oxide such as LiCoO ₂ constituting the positive electrode active material. The amount is 10% by mass or more.
Copper is generally included at 0.5 wt% to 15 wt%, typically 1 wt% to 10 wt%.

(Leaching process)
In the leaching step, the battery powder obtained in the crushing / sieving step is added to the acidic leaching solution and leached. Here, as shown in FIG. 1, the non-roasted battery powder and the roasted battery powder described above are leached by contacting with an acidic leachate.

If only non-roasted battery powder is leached, the copper contained therein will dissolve in a short time.
On the other hand, as in this embodiment, non-roasted battery powder is mixed with roasted battery powder that has been subjected to a roasting treatment at a temperature of 450 ° C. or higher, and these are brought into contact with an acidic leachate. The simple metals in the roasted battery powder, especially cobalt, nickel, manganese, iron, aluminum, etc., are dissolved earlier than copper because they are base metals than copper. That is, while the single metal remains as a solid in the acidic leaching solution, the redox potential (silver / silver chloride potential reference) is kept low, and the increase in copper leaching rate is suppressed.

  In particular, here, the amount of non-roasted battery powder and roasted battery powder to be brought into contact with the acidic leachate is adjusted so that the redox potential (ORP value, silver / silver chloride potential reference) of the acid leachate during leaching is 0 mV or less. It is preferable to adjust. This is because the leaching rate of copper starts to increase when the oxidation-reduction potential exceeds 0 mV. From the viewpoint of more effectively suppressing the copper leaching rate, the ratio of the non-roasted battery powder to the roasted battery powder is more preferably set to a ratio at which the oxidation-reduction potential is -100 mV or less.

Specifically, for the above reasons, the ratio of non-roasted battery powder to roasted battery powder is preferably expressed as a weight ratio of non-roasted battery powder / roasted battery powder to 2 or less. In particular, 1 or less is more preferable. If the ratio of the roasted battery powder is too small, the amount of elemental cobalt and the like is decreased, and there is a concern that the leaching rate of copper increases during the leaching. There is no particular problem that the ratio of the roasted battery powder is large.
In order to predetermine the weight ratio between the non-roasted battery powder and the roasted battery powder, a weight test is performed in advance to perform acid leaching at a predetermined weight ratio so that the ORP value is 0 mV or less. It is desirable to check the ratio.

  By leaching as described above, the leaching rate of copper into the leaching solution at the end of leaching is preferably 1% or less. In particular, copper does not leached into the leaching solution at all, and the copper leaching rate is 0%. More preferably.

  Here, prior to bringing the non-roasted battery powder and the roasted battery powder into contact with the acidic leachate, the non-roasted battery powder and the roasted battery powder are mixed to form a mixed battery powder, In addition to being able to contact, any battery powder can be contacted with the acidic leachate, and then the remaining battery powder can be contacted with the acidic leachate. That is, it is sufficient that the non-roasted battery powder and the roasted battery powder can be regarded as being substantially acid leached with the acid leaching solution.

  In the leaching step as described above, cobalt and nickel are dissolved, but the pH of the acidic leaching solution is gradually increased so that copper is not dissolved. Specifically, the pH of the acidic leachate during leaching can be 0 to 2.0. If the pH at this time is too high, the leaching rate of cobalt and nickel may not be sufficient. On the other hand, if the pH is too low, leaching of metals such as cobalt, nickel, and aluminum proceeds rapidly, and This is because leaching may occur and cost may increase due to pH adjustment when pH needs to be raised in a subsequent process.

  In the leaching step, the leaching time from when the battery powder is added to the acidic leaching solution to the end of leaching is preferably 0.5 hours to 10 hours. If the reaction time is too short, cobalt or nickel to be dissolved may not be sufficiently dissolved. On the other hand, if the leaching time is too long, the dissolution of cobalt or the like may end and the dissolution of copper may start. A more preferable range of the leaching time is 1 hour to 5 hours, more preferably 1 hour to 3 hours.

(Copper separation process)
After the above leaching step, metals other than copper, particularly cobalt and nickel, etc. are almost dissolved, and the copper leaching solution is subjected to a known method such as solid-liquid separation in the copper leaching solution. The leaching residue and the liquid after leaching can be separated. As described above, in the leaching process, copper remains and precipitates as a solid in the leaching solution, so the leaching residue obtained in this copper separation step contains a large amount of copper solids, while the leaching solution contains almost no copper. It will not be included.

(Recovery process)
A recovery step can be performed to recover valuable metals such as cobalt and nickel from the leached solution obtained as described above.
In this recovery method, each metal including valuable metals dissolved therein is separated from the leached solution using, for example, general solvent extraction or neutralization. In the embodiment of the present invention, since the leached solution contains almost no copper, the process required for the separation and removal of copper here can be simplified or omitted.

  Specifically, for example, neutralization / separation or solvent extraction for removing iron and aluminum is first performed. Then, from the resulting solution, manganese and optionally remaining aluminum are removed by solvent extraction or oxidation, and cobalt and nickel are sequentially recovered by solvent extraction with an extractant according to each metal. Later, leave the lithium in the aqueous phase. Cobalt in the solvent can be transferred to the aqueous phase by back extraction and recovered by electrowinning. Similarly, nickel in the solvent can be recovered by back extraction and electrowinning. Lithium can be carbonated and recovered as lithium carbonate.

  In this case, sulfurization / separation, which has been performed to remove copper after removing iron and aluminum by the conventional method, is no longer necessary, so that the processing efficiency can be greatly improved and the cost required for sulfurization / separation is effective. Can be reduced.

  Next, the lithium ion battery scrap leaching method according to the present invention was experimentally carried out and the effect thereof was confirmed, and will be described below. However, the description here is for illustrative purposes only and is not intended to be limiting.

(Reference Example 1)
As the lithium ion battery scrap, waste lithium ion battery scrap materials containing the components shown in Table 1 were used, and pulverized using a pulverizer without being subjected to roasting. After the crushing treatment, it was sieved with a vibrating sieve having a sieve size of 1 mm, and the non-roasted battery powder obtained under the sieve was subjected to a leaching treatment with sulfuric acid. The leaching treatment was performed at 70 ° C. for 3 hours by adding 1 equivalent of sulfuric acid and water to 58.9 g of battery powder to obtain a slurry having a pulp concentration of 100 g / L. Since this non-roasted battery powder is not roasted, LiCoO ₂ is not decomposed, no base metal Co is present in the solution, and the redox potential of LiCoO ₂ is high. Thus, the ORP of the acidic leachate was as high as 788 mV. As a result, Cu was leached and the leaching rate of Cu was 75%. The acidic leaching solution also contained Al that was lower than Cu, but Cu leaching occurred depending on conditions such as Al concentration and ORP.

(Reference Example 2)
The waste lithium ion battery scrap material used in Reference Example 1 was subjected to low temperature roasting treatment at 400 ° C. for 2 hours, and the waste lithium ion battery scrap material subjected to low temperature roasting was pulverized by a pulverizer. After being crushed, it was sieved with a vibrating sieve, and the non-roasted battery powder obtained under the sieve was leached with sulfuric acid. The leaching conditions were the same as those in Reference Example 1. Since this non-roasted battery powder is not substantially roasted, the decomposition of LiCoO ₂ into CoO or metal into cobalt is insufficient, the production of metal cobalt is small, and undecomposed LiCoO ₂ As a result, the ORP of the leaching solution was as high as 553 mV. As a result, Cu was leached, and the leaching rate of Cu was 48%.

(Reference Example 3)
The waste lithium ion battery scrap material used in Reference Example 1 was subjected to heat treatment at 550 (450 to 650) ° C. for 2 hours using a rotary kiln furnace as a roasting furnace, and roasted waste lithium ion battery. The scrap material was pulverized by a pulverizer. The waste lithium ion battery scrap material that had been roasted and pulverized was sieved with a vibrating sieve, and the baked battery powder obtained under the sieve was subjected to a leaching treatment with sulfuric acid. The leaching treatment was performed at 70 ° C. for 3 hours by adding 4 equivalents of roasted battery powder to a slurry having a pulp concentration of 100 g / L by adding 1 equivalent of sulfuric acid and water. In this roasted battery powder, LiCoO ₂ is reduced and decomposed into CoO and metal Co by roasting, and the ORP of the solution is as low as −315 mV, and metal Co that is lower than Cu is present in the solution. And since Al which is lower than Cu is also included, the leaching of Cu was suppressed, and the leaching rate of Cu was less than 0.1%.

Example 1
The non-roasted battery powder obtained in Reference Example 1 and the roasted battery powder obtained in Reference Example 3 were mixed at a mixing ratio of 1: 3 and subjected to leaching treatment with sulfuric acid. The leaching conditions were such that the mixed battery powder was added to 1 equivalent of sulfuric acid solution at 70 ° C. for 3 hours. At this time, the ORP of the acidic leachate was −311 mV, and the battery powder was prepared so as to be less than 0 mV. As a result, Cu leaching rate is less than 0.1%, Co leaching rate is 91%, Al leaching rate is 83%, Cu leaching can be sufficiently suppressed, Co leaching rate is increased and improved. Was confirmed.

(Example 2)
The non-roasted battery powder obtained in Reference Example 2 and the roasted battery powder obtained in Reference Example 3 were mixed at a mixing ratio of 1: 1 and subjected to leaching treatment with sulfuric acid. The leaching conditions were such that the mixed battery powder was added to 1 equivalent of sulfuric acid solution at 70 ° C. for 3 hours. At this time, the ORP of the solution was −248 mV, and the battery powder was prepared so as to be less than 0 mV. As a result, Cu leaching rate is less than 0.1%, Co leaching rate is 95%, Al leaching rate is 66%, Cu leaching can be sufficiently suppressed, Co leaching rate is increased and improved. Was confirmed.

(Example 3)
The non-roasted battery powder obtained in Reference Example 1 and the roasted battery powder obtained in Reference Example 3 were mixed at a mixing ratio of 3: 1 and subjected to leaching treatment with sulfuric acid. The leaching conditions were such that the mixed battery powder was added to 1 equivalent of sulfuric acid solution at 70 ° C. for 3 hours. The ORP of the solution at this time was 114 mV. As a result, the leaching rate of Cu was 54%, and the leaching rate of Cu could be reduced as compared with Reference Example 1 in which only the non-roasted battery powder was leached.

  From the above results, by mixing non-roasted battery powder and roasted battery powder and bringing this mixed battery powder into contact with the acid leaching solution and leaching, copper leaching can be achieved even with non-roasted battery powder. It was found that it can be effectively suppressed.

Claims (5)

  Lithium ion battery scrap leaching as powdered battery powder, leaching lithium ion battery scrap by leaching non-roasted battery powder containing at least copper together with roasted battery powder in contact with acidic leachate Method.   The method for leaching lithium ion battery scrap according to claim 1, wherein the roasted battery powder contains at least one elemental metal selected from the group consisting of cobalt, nickel and manganese.   The lithium ion battery scrap leaching method according to claim 1 or 2, wherein the roasted battery powder contains a single metal of iron and / or aluminum.   The amount of the non-roasted battery powder and the roasted battery powder to be brought into contact with the acidic leachate is adjusted so that the redox potential (silver / silver chloride potential reference) of the acidic leachate during leaching is 0 mV or less. 4. The method for leaching lithium ion battery scrap according to any one of 3 above.   Using the leaching method of the lithium ion battery scrap according to any one of claims 1 to 4, from the leached liquid obtained by leaching the non-roasted battery powder and the roasted battery powder, A method for recovering metal from lithium-ion battery scrap, which recovers contained metal.