JP6483569B2 - Lithium-ion battery processing method - Google Patents

Description

  The present invention relates to a method for treating a lithium ion battery containing cobalt and nickel, and in particular, proposes a technique that can contribute to improvement of treatment efficiency and cost reduction.

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 desired that the above valuable metals such as nickel and cobalt, especially cobalt, be easily recovered from a large amount of lithium ion battery scrap at a relatively low cost for reuse.

In order to treat discarded lithium-ion batteries for the recovery of valuable metals, first, the lithium ion battery is roasted to remove the harmful electrolyte contained therein and render it harmless. Then, crushing and sieving are sequentially performed, and a crushing and sieving step is performed in which aluminum contained in the housing and the positive electrode base material is removed to some extent.
Subsequently, the battery powder obtained under the sieving and sieving step is added to the leaching solution and leached, and a leaching step is performed in which lithium, nickel, cobalt, manganese, aluminum, and the like that can be contained therein are dissolved in the solution.

  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, 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 leached solution obtained by leaching the lithium ion battery, many processes are required. Therefore, if the specific metal contained in the battery powder can be separated in advance as a solid without dissolving it in the leachate, various treatments applied to the post-leaching solution to separate and recover each metal in the subsequent recovery step Among them, the processing necessary for recovering the specific metal separated in advance can be simplified or omitted, which is effective from the viewpoint of processing efficiency and cost.
In particular, if a large amount of nickel is dissolved in the solution after leaching, for example, when cobalt is extracted and recovered using solvent extraction, the extraction rate of cobalt is lowered to separate nickel into the solution after extraction. Since adjustment may be necessary, it is desirable to reduce the leaching rate of nickel into the leaching solution.

  An object of the present invention is to solve such a problem. The object of the present invention is to treat a lithium ion battery containing nickel in a leaching process, and a metal such as cobalt is contained in the leaching solution. An object of the present invention is to provide a method of treating a lithium ion battery that can improve the processing efficiency and reduce the cost by reducing the leaching rate of nickel while being sufficiently dissolved.

  The inventor heated the lithium ion battery in a heating process prior to the leaching process under predetermined conditions, and then adjusted the temperature conditions of the leaching liquid used in the leaching process and the leaching liquid during the leaching. It has been found that the leaching rate of nickel into the leachate can be lowered while sufficiently dissolving the metal in the leachate. This is considered to be due to the fact that the metal such as cobalt is changed to a form in which acid leaching is likely to occur in the heating process under a predetermined condition, and further, in the leaching process, nickel is not dissolved so much. It is not limited to theory.

  Based on such knowledge, the method of treating a lithium ion battery of the present invention is a method of treating a lithium ion battery containing cobalt and nickel, and the temperature of the lithium ion battery is set to 1 hour by heating the lithium ion battery. A heating step of maintaining at 550 ° C. to 650 ° C. for ˜4 hours, and a battery powder obtained after the heating step of 0.9 to 1.5 times mol necessary to dissolve all metal components contained in the battery powder And a leaching step of leaching the battery powder at a temperature of 60 ° C. to 80 ° C. by adding to an leaching solution containing an equivalent amount of sulfuric acid.

Further, the inventor considered that it is preferable to reduce the amount of aluminum dissolved in the leachate from the viewpoint of further simplifying or omitting the treatment in the recovery step after the leaching step, and the amount of aluminum contained in the battery powder. We studied diligently about the reason why there are relatively many. As a result, when the lithium ion battery is roasted in the heating process, the temperature of the lithium ion battery is rapidly increased to a predetermined high temperature in the temperature rising process. The casing that composes the exterior ruptures, and as a result, the aluminum contained in the casing and the positive electrode base material is oxidized and embrittled, and is easily crushed during crushing. The knowledge that it is contained in powder was obtained. Furthermore, such a rupture of the casing causes a rapid temperature rise of the lithium ion battery during heating to generate a large amount of gas in the casing due to rapid vaporization of the electrolyte inside, and the generation flow rate of this gas is reduced. It has been found that the cause is that the casing expands by exceeding the outflow rate to the outside of the casing.
Therefore, during the heating process of the lithium ion battery in the heating process, the temperature rising rate of the lithium ion battery is controlled so that almost all the gas in the housing slowly flows out while the temperature is relatively low. It was thought that it could be effectively roasted without rupturing the lithium ion battery.

Accordingly, in the heating step, the temperature of the lithium ion battery is raised in two stages, and the first stage heating brings the temperature of the lithium ion battery within a range of 200 ° C. to 400 ° C., and the temperature falls within that range. In the meantime, it is preferable to terminate the outflow of gas from the inside of the casing of the lithium ion battery.
In the heating step, after the outflow of gas from the inside of the lithium ion battery casing is completed by the first stage heating, the temperature of the lithium ion battery is raised to 550 ° C. to 650 ° C. as the second stage heating. Is more preferable.

  According to the method for treating a lithium ion battery of the present invention, in a heating step of heating the lithium ion battery under a predetermined condition, a metal such as cobalt that can be contained therein is easily leached and then obtained. By performing a leaching step of leaching the battery powder under predetermined conditions, metals such as cobalt are sufficiently dissolved in the leachate, while nickel does not dissolve much, thereby improving processing efficiency and cost. Can be reduced.

It is a flowchart which shows the processing method of the lithium ion battery which concerns on 1st embodiment of this invention. It is a flowchart which shows the processing method of the lithium ion battery which concerns on 2nd embodiment of this invention. It is a flowchart which shows the processing method of the lithium ion battery which concerns on 3rd embodiment of this invention. It is a graph which shows the change of the cobalt and nickel leaching rate with respect to the baking temperature in a test example. It is a graph which shows the change of nickel / cobalt concentration ratio with respect to the baking temperature in a test example.

Hereinafter, embodiments of the present invention will be described in detail.
The processing method of the lithium ion battery which concerns on one Embodiment of this invention is directed to the lithium ion battery containing cobalt and nickel, and heats such a lithium ion battery so that it may illustrate in FIG. The heating step of maintaining the temperature of 550 ° C. to 650 ° C. for 1 to 4 hours, and the battery powder obtained after the heating step, 0.9 required to dissolve all the metal components contained in the battery powder A leaching step of leaching the battery powder at a temperature of 60 ° C. to 80 ° C., and further adding a leaching solution obtained in the leaching step. In addition, a leaching residue containing nickel and a nickel separation step of separating into a solution after leaching, and a recovery step of separating valuable metals by separating each metal in the solution after leaching.

(Lithium ion battery)
The lithium ion battery targeted by the present invention may be any lithium ion battery that can be used in a mobile phone or other various electronic devices. Among these, it is preferable from the viewpoint of effective utilization of resources to target so-called lithium ion battery scrap that is discarded due to the life of the battery product, manufacturing defects, or other reasons.

  Here, this invention is directed to a lithium ion battery containing cobalt and nickel. In general, the lithium ion battery according to the embodiment of the present invention may include cobalt at 18% by mass to 25% by mass and nickel at 1% by mass to 10% by mass.

  In addition, the lithium ion battery may have a housing containing aluminum as an outer package that encloses the periphery thereof. Examples of the housing include those made only of aluminum and those containing aluminum, iron, aluminum laminate, and the like.

Specifically, the lithium ion battery 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 in the casing. In general, the positive electrode active material includes an aluminum foil (positive electrode base material) applied and fixed with, for example, polyvinylidene fluoride (PVDF) or other organic binder. In addition, the lithium ion battery may contain copper, iron, or the like.
Further, in general, a lithium ion battery includes an electrolytic solution in a casing. For example, ethylene carbonate, diethyl carbonate, or the like may be used as the electrolytic solution.

  The lithium ion battery encapsulated in the housing can have a substantially square or rectangular planar outline shape. In this case, as dimensions before processing, for example, the length is 40 mm to 80 mm, and the width is Although 35 mm-65 mm and a thickness of 4 mm-5 mm can be made into a target, it is not limited to the thing of this dimension.

(Heating process)
In this embodiment, as shown in FIG. 1, a heating step is performed on the lithium ion battery. This heating process raises the temperature of the lithium ion battery, removes the internal electrolyte, renders it harmless, decomposes the binder that binds the aluminum foil and the positive electrode active material, and crushes and sifts The separation of the aluminum foil and the positive electrode active material is promoted to increase the recovery rate of the positive electrode active material recovered under the sieve, and further, metals such as cobalt contained in the lithium ion battery are leached in the leaching step described later. This is done for the purpose of changing to an easy form.

In particular, in this battery heating step, for example, after a temperature raising process described later, the lithium ion battery is heated so that aluminum having a melting point of 660 ° C. does not melt, and the temperature of the lithium ion battery is 550 ° C. to 650 ° C. Once the range is reached, the temperature range is maintained for 1 to 4 hours. 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.

  When the holding temperature in this heating step is less than 550 ° C., the effect of suppressing the leaching rate of nickel in sulfuric acid leaching in the subsequent step cannot be obtained. On the other hand, when the temperature is raised to a temperature exceeding 650 ° C., the oxidation and embrittlement of the aluminum progresses, and the aluminum is easily crushed in the crushing and sieving process. Increasing the work and cost in later collection steps.

From such a viewpoint, the temperature of the lithium ion battery in the heating step is preferably 550 ° C to 650 ° C.
This temperature can be measured by measuring the surface temperature of the casing of the lithium ion battery.

  The time kept within the above temperature range is 1 to 4 hours. This is because if it is less than 1 hour, the effect of suppressing the nickel leaching rate in sulfuric acid leaching in the subsequent process cannot be obtained, and if it is longer than 4 hours, there is no particular problem, but the productivity is lowered. is there.

By the way, in this heating process, if the temperature of the lithium ion battery is rapidly increased using, for example, an incinerator, the housing may be ruptured. As a result, the casing is oxidized and becomes brittle, so that when the heated lithium ion battery is crushed, a large amount of aluminum constituting the casing and the like is contained in a fine powder form. Since such aluminum cannot be completely removed by sieving and is mixed into the battery powder under the sieving and sieving, the work and cost for recovering it are increased.
Such a burst during heating of the lithium ion battery is caused by a rapid rise in the temperature of the lithium ion battery from the start of heating, so that the electrolyte in the casing rapidly vaporizes into a gas, and It is considered that the gas in the casing that is generated in a larger amount than the amount of gas that can flow out of the casing expands and bursts the casing.

In order to cope with this, as in the embodiment shown in FIG. 2 and FIG. 3, heating 1 (first stage heating) and heating 2 (two stages) in which the temperature of the lithium ion battery is raised in two stages in the heating process. Eye heating).
In the first heating 1, the temperature of the lithium ion battery is set in the range of 200 ° C to 400 ° C. Here, when the temperature of the lithium ion battery is raised and the temperature reaches within the range of 200 ° C. to 400 ° C., the gas starts to flow out from the inside of the housing. While the temperature is within the range of 200 ° C. to 400 ° C. The temperature rise rate of the lithium ion battery is controlled, for example, by reducing it, and the outflow of gas from the casing is terminated during this time.

  According to this, since the gas generation due to the evaporation of the electrolyte is performed slowly until the outflow of the gas from the housing is completed, the gas is prevented from being generated rapidly enough to expand the housing. It is possible to effectively prevent rupture of the housing and embrittlement due to oxidation. After the outflow of the gas is completed, the temperature is further increased to change the valuable metal contained in the lithium ion battery into a form in which acid leaching can be easily performed. Moreover, if the temperature is raised too much by such heating 1, the gas flowing out of the casing is ignited, causing a rapid rise in the temperature of the lithium ion battery. In this embodiment, such gas is ignited. The heating rate is controlled so as not to invite.

  Here, whether or not the outflow of gas from the housing is completed is confirmed by visually confirming the mist that has flowed out of the housing or by analyzing flammable components in the exhaust gas. Is possible.

Here, the temperature range of the heating 1 is set to 200 ° C. to 400 ° C. in order to make the flow rate of the gas generated by the vaporization of the electrolytic solution a predetermined amount or less. Thereby, until the end of the heating process, the state in which the lithium ion battery remains in its original form, that is, the property in which the lithium ion battery is wrapped in the casing is maintained, and is included in the casing and the like by subsequent crushing and sieving Aluminum can be sufficiently removed.
In other words, if the temperature of the lithium ion battery is less than 200 ° C. by heating 1, the gas does not flow out of the casing, and the effect of preventing explosion cannot be sufficiently obtained. If the temperature exceeds 400 ° C. before the outflow of the gas, the housing may burst due to an increase in the gas generation flow rate. From such a viewpoint, in the heating 1, it is preferable to terminate the outflow of gas within a temperature range of 200 ° C. to 400 ° C., and in particular, the outflow of gas may be terminated within a temperature range of 220 ° C. to 380 ° C. More preferred.

Here, the time of heating 1 in the range of 200 ° C. to 400 ° C. varies depending on the type, size, and other conditions of the lithium ion battery, but the temperature of the lithium ion battery reaches the range of 200 ° C. to 400 ° C. It is possible to set the time from when the time has elapsed to when the time has elapsed, preferably 10 minutes or more, more preferably 20 minutes or more. That is, the average temperature rising rate of the lithium ion battery within the range of 200 ° C. to 400 ° C. is preferably 20 ° C./min or less, and more preferably 10 ° C./min or less. That is, when the average temperature rising rate of the lithium ion battery in the range of 200 ° C. to 400 ° C. is higher than 20 ° C./min, in some cases, the outflow of gas from the inside of the casing is not sufficiently completed. This is because the temperature may exceed 400 ° C. and there is a concern that the housing may burst.
On the other hand, the longer the time of heating 1 in the range of 200 ° C. to 400 ° C., the more reliably the gas outflow can be terminated. If the length is too long, the processing efficiency decreases due to an increase in processing time. Thereby, it can be normally made into 60 minutes or less, and also can be made into 30 minutes or less.

  In heating 1, until the outflow of gas from the casing is completed, if the temperature of the lithium ion battery does not exceed 400 ° C., gas can be effectively outflowed while preventing burst due to rapid outflow of gas. . Here, it is common to raise gently within the range of 200 degreeC-400 degreeC until the outflow of gas is complete | finished. However, if possible, the temperature of the heating 1 may be held at one or more specific temperatures within a range of 200 ° C. to 400 ° C. until the outflow of gas is completed. Note that a crushing / sieving step as described later may be performed after the heating 1, but in that case, it is desirable to raise the temperature once to 450 ° C. or more after the outflow of gas. However, since the aluminum foil becomes brittle when the temperature is too high, it is preferably 550 ° C. or lower, and more preferably 500 ° C.

  After the gas has completely flowed out of the casing of the lithium ion battery in the heating 1, the heating 2 is performed to increase the temperature of the lithium ion battery to 550 ° C. to 650 ° C. As described above, cobalt is easily leached. Change to form.

  As long as the temperature of the lithium ion battery can be controlled as described above, this heating step can be performed using various heating facilities such as a rotary kiln furnace and other various furnaces. If the temperature of the lithium ion battery can be controlled as described above, a furnace that performs heating in an air atmosphere can also be used. Therefore, the treatment method of the present invention is advantageous in that it can be carried out without using special equipment for roasting lithium ion batteries.

(Crushing and sieving process)
The lithium ion battery after being heated in the above heating step is subjected to crushing for removing the positive electrode material and the negative electrode material from the casing and sieving with a predetermined sieve for removing aluminum powder that may be contained therein. Is done. 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.

  As described above, when heating 1 and heating 2 are performed to raise the temperature in two stages in the heating process, the crushing and sieving process is performed after heating 1 and heating 2 as shown in FIG. In addition, as shown in FIG. 3, it can be performed between heating 1 and heating 2.

The crushing of the lithium ion battery is mainly performed to destroy the casing of the lithium ion battery 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 be crushed by applying an impact while cutting the lithium ion battery. 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. A screen can be installed at the outlet of the pulverizer, whereby the lithium ion battery is discharged from the pulverizer through the screen when pulverized to a size that can pass through the screen.

  The lithium ion battery after crushing is sieved using a sieve with 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.

The aluminum content in the battery powder obtained after the heating step is preferably less than 5% by mass. The smaller the amount of aluminum in the battery powder, the less time is required for the subsequent process, and the more the positive electrode active material can be prevented from being entrained by melting the aluminum in the powder heating process of the next process. This is because the metal recovery rate can be greatly improved.
One effective means for reducing the content of aluminum contained in the battery powder obtained after the heating step to less than 5% by mass is to perform a crushing and sieving step between heating 1 and heating 2.

(Leaching process)
In the leaching step, the battery powder obtained under the sieve in the heating step is added to the leaching solution that is a sulfuric acid acidic solution and leached.
Here, since the cobalt component in the battery powder is effectively changed into cobalt oxide (CoO) and simple substance cobalt by heating under the predetermined temperature conditions in the heating step described above, these are easily converted into the leachate. Can be dissolved.

  On the other hand, the details of the reaction of nickel in the battery powder are unknown, but dissolution in the leachate can be suppressed by heat treatment at an appropriate temperature and time, and the leaching rate of nickel can be lowered. .

  Here, the leaching solution used in the leaching step includes 0.9 to 1.5 times the molar equivalent of sulfuric acid necessary for dissolving all the metal components contained in the battery powder. Those containing less than 0.9-fold molar equivalent of sulfuric acid relative to the total metal components cannot effectively dissolve valuable metals such as cobalt to be dissolved, while containing sulfuric acid exceeding 1.5-fold molar equivalent. This is because the leaching rate of most metals including nickel increases from the beginning of leaching, and the leaching rate of nickel cannot be reduced.

Here, the 0.9 to 1.5-fold molar equivalent necessary for dissolving all the metal components contained in the battery powder can be determined based on the following formula.
Li ₂ CO ₃ + H ₂ SO ₄ → Li ₂ SO ₄ + H ₂ O + CO ₂ (gas)
Co + H ₂ SO ₄ + 1 / 2O ₂ → CoSO ₄ + H ₂ O
Ni + H ₂ SO ₄ + 1 / 2O ₂ → NiSO ₄ + H ₂ O
Mn + H ₂ SO ₄ + 1 / 2O ₂ → MnSO ₄ + H ₂ O
Fe + H ₂ SO ₄ + 1 / 2O ₂ → FeSO ₄ + H ₂ O
Cu + H ₂ SO ₄ + 1 / 2O ₂ → CuSO ₄ + H ₂ O
2Al + 3H ₂ SO ₄ + 3 / 2O ₂ → Al ₂ (SO ₄ ) ₃ + 3H ₂ O
From this viewpoint, the leachate should contain 0.9 to 1.5 times molar equivalent of sulfuric acid relative to all metal components, and more preferably 0.9 to 1.1 times molar equivalent of sulfuric acid.

  In such a leaching step, the pH of the leaching solution can be 0 to 2.0. If the pH at this time is too high, the leaching rate of cobalt or the like may not be sufficient. On the other hand, if the pH is too low, the leaching will proceed rapidly and the nickel will dissolve, This is because when the pH needs to be raised, there is a possibility that the cost may increase due to pH adjustment.

  In this leaching step, the temperature of the leaching solution after adding the battery powder is set to 60 ° C to 80 ° C. Thereby, cobalt can be effectively dissolved without increasing the leaching rate of nickel. If the temperature of the leaching solution is less than 60 ° C., the leaching rate of the dissolved cobalt decreases, and if it is higher than 80 ° C., the leaching proceeds rapidly and the nickel is dissolved, and the nickel is selectively leached. Can not be separated. Therefore, the temperature of the leachate is preferably 60 ° C to 80 ° C.

  By leaching the battery powder as described above, the leaching rate of nickel into the leaching solution at the end of leaching is preferably 50% or less, and more preferably 20% or less.

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

(Nickel separation process)
After the above leaching step, cobalt is almost dissolved, and the nickel leaching solution is separated into a leaching residue and a leached solution by performing a known method such as solid-liquid separation in the nickel separation step. be able to. As described above, in the leaching process, a large amount of nickel remains as a solid in the leaching solution. Therefore, the leaching residue obtained in this nickel separation step contains a large amount of nickel as a solid, while the leaching solution contains almost no nickel. It will not be included.

(Recovery process)
A recovery step can be performed to recover a metal such as cobalt from the post-leaching 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, the amount of nickel in the solution after leaching is small or not contained at all, so that the processing required for separation / removal of nickel here can be simplified or omitted.

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

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

Example 1
A lithium ion battery containing cobalt as a main component was heated at 550 ° C. for 2 hours in an air atmosphere using a crucible furnace. The heat-treated battery whose temperature was lowered to room temperature was crushed with a crusher. The crushed material was sieved with a sieve having an opening of 1 mm, and a powdery cobalt concentrate was recovered under the sieve. Table 1 shows the quality of the cobalt concentrate.

  The cobalt concentrate was added with a chemical equivalent of sulfuric acid necessary for dissolving all the metals in the raw material with a pulp concentration of 100 g / L, stirred at 80 ° C. for 2 hours, and then subjected to solid filtration by vacuum filtration. The amount of the leachate and the weight of the leach residue were measured, the concentration of the leach solution and the quality of the leach residue were analyzed, and the distribution ratio of each component of the leach liquor and residue was calculated. The concentration of the leachate is shown in Table 2, the quality of the leach residue is shown in Table 3, and the distribution ratio of each component is shown in Table 4.

  From the results shown in Table 4, it can be seen that the leaching rate of cobalt was relatively high at 92.1%, and the leaching rate of nickel was 22.0%, which could be effectively suppressed.

(Comparative Example 1)
A lithium ion battery containing cobalt as a main component was heated at 450 ° C. for 2 hours in an air atmosphere using a crucible furnace. The heat-treated battery whose temperature was lowered to room temperature was crushed with a crusher. The crushed material was sieved with a sieve having an opening of 1 mm, and a powdery cobalt concentrate was recovered under the sieve. Table 5 shows the quality of the cobalt concentrate.

  The cobalt concentrate was added with a chemical equivalent of sulfuric acid necessary for dissolving all the metals in the raw material with a pulp concentration of 100 g / L, stirred at 80 ° C. for 2 hours, and then subjected to solid filtration by vacuum filtration. The amount of the leachate and the weight of the leach residue were measured, the concentration of the leach solution and the quality of the leach residue were analyzed, and the distribution ratio of each component of the leach solution and the leach residue was calculated. Table 6 shows the concentration of the leachate, Table 7 shows the quality of the leaching residue, and Table 8 shows the distribution ratio of each component.

  From the results shown in Table 8, it can be seen that the leaching rate of cobalt is as high as 99.8%, but the leaching rate of nickel was 56.6% and could not be suppressed so much.

(Test example)
Under substantially the same conditions as in Example 1 and Comparative Example 1, tests were performed in which the incineration heating temperature was changed within the range of 400 to 650 ° C. and the heating time within the range of 1 to 4 hours. Fig. 4 shows the leaching rate of cobalt and nickel when the cobalt concentrate recovered under the sieve after crushing and sieving is leached with sulfuric acid, and the ratio of nickel and cobalt concentration in the sulfuric acid leaching solution = nickel concentration ÷ cobalt concentration (Ppm) is shown in FIG.

From FIG. 4, the infiltration of the lithium ion battery is carried out at 500 to 650 ° C. for 1 to 4 hours, so that the cobalt leaching rate when the cobalt concentrate recovered under the sieve after crushing and sieving is leached with sulfuric acid is 92% or more. And the nickel leaching rate can be reduced to 60% or less. The nickel / cobalt concentration ratio of the sulfuric acid leachate at this time is 1,900 ppm or less.
Furthermore, by incinerating the lithium ion battery at 550 to 650 ° C. for 1 to 4 hours, the cobalt leaching rate when the cobalt concentrate recovered under the sieve after crushing and sieving is leached with sulfuric acid is 92% or more, It can also be seen that the nickel leaching rate can be 44% or less. At this time, the nickel / cobalt concentration ratio of the sulfuric acid leachate is 1,500 ppm or less.

Claims (3)

A method of treating a lithium ion battery comprising cobalt and nickel comprising:
A heating step of heating a lithium ion battery and maintaining the temperature of the lithium ion battery at 550 ° C. to 650 ° C. for 1 hour to 4 hours, and a battery powder obtained after the heating step, all metal components contained in the battery powder A leaching step of leaching the battery powder at a temperature of 60 ° C to 80 ° C. A method for treating a lithium ion battery.   In the heating step, the temperature of the lithium ion battery is raised in two stages, and the temperature of the lithium ion battery is set in the range of 200 ° C. to 400 ° C. in the first stage heating, while the temperature is within the range. The processing method of the lithium ion battery according to claim 1, wherein the outflow of gas from the inside of the casing of the lithium ion battery is terminated.   The temperature of the lithium ion battery is increased to 550 ° C to 650 ° C as the second stage heating after the outflow of gas from the inside of the lithium ion battery casing by the first stage heating in the heating step. The processing method of the lithium ion battery of 2.