JP6562212B2 - Method and apparatus for thermal decomposition treatment of lithium ion battery - Google Patents

Description

  The present invention relates to a processing method and a processing apparatus for reducing the burden of exhaust gas treatment by reducing the amount of hydrogen fluoride gas contained in exhaust gas in the thermal decomposition of a lithium ion battery.

The positive electrode active material of a lithium ion battery (LIB) is composed of lithium cobaltate, lithium nickelate, lithium manganate, and the like, and the negative electrode active material is composed of graphite, lithium titanate, or the like. These active materials are fixed to a current collector made of an aluminum foil in the case of a positive electrode and a copper foil in the case of a negative electrode by a fluorine-based binder such as polyvinylidene fluoride (PVDF). The electrolyte is mainly used in which a fluorine-containing lithium salt such as lithium hexafluorophosphate (LiPF ₆ ) or lithium tetrafluoroborate (LiBF ₄ ) is dissolved in an organic solvent such as carbonates. ing. Thus, the lithium ion battery contains various fluorine compounds.

  As a method for treating a used lithium ion battery, a heat treatment for the purpose of detoxifying the electrolyte and reducing the volume of combustible materials such as a separator and an adhesive resin has been conventionally known. For example, in Patent Document 1 (Japanese Patent Laid-Open No. 2012-204000), a lithium ion battery is thermally decomposed in a vapor atmosphere or an inert gas atmosphere to condense decomposition products, and a condensed liquid containing generated hydrogen fluoride is obtained. A treatment method in which a calcium salt is added to perform water treatment is described. Patent Document 2 (Japanese Patent Laid-Open No. 2013-187142) describes a method in which a lithium ion battery is placed in a heat treatment tank and the heat treatment is performed by circulating gas in the tank.

  Patent Document 3 (Japanese Patent Laid-Open No. 2005-197149) describes a treatment method in which a lithium ion battery is heated and a gas containing a generated fluorine compound is reacted with aluminum hydroxide to be immobilized. Patent Document 4 (Japanese Patent Application Laid-Open No. 2014-227565) discloses that a calcium ion or cement raw material is added to a lithium ion battery and supplied into the furnace, and the exhaust gas generated by the cement baking apparatus is roasted as a heat source, and the roasting furnace A processing method for returning the exhaust gas to the cement baking apparatus is described. Patent Document 5 (Japanese Patent No. 3079285) describes a processing method for roasting a lithium ion battery and recovering valuable materials from the residue.

In heat treatment of a lithium ion battery, hydrogen fluoride and phosphoric acid are generated when the lithium ion battery is thermally decomposed in a non-oxidizing atmosphere (an atmosphere of inert gas, nitrogen, superheated steam, carbonic acid, or the like). In the conventional treatment method, some of these acidic gases are transferred to the exhaust gas, so there is a problem of polluting the environment, and the burden of treating the exhaust gas is large. In particular hydrogen fluoride, fluorine concentration in the exhaust gas must be reduced below 10 mg / Nm ³ or less to 30 mg / Nm ³ by environmental regulations, a large burden on the exhaust gas treatment and high fluoride concentration in the exhaust gas Become.

  In the treatment method of Patent Document 1, fluorine is fixed using a calcium salt. However, it is expensive to introduce the calcium salt from outside the system, and calcium remains in the pyrolysis residue, which is used when recovering lithium. This increases the burden on the recovery process. In the method of Patent Document 2, treatment of hydrogen fluoride generated during heating becomes a problem. In the method of Patent Document 3, the steps until obtaining aluminum hydroxide to be a fluorine fixing agent are complicated. In the method of Patent Document 4, the fluorine contained in the exhaust gas is returned to the combustion device, but calcium and cement raw materials are mixed as impurities in the residue, which causes a problem that adversely affects the recycling of valuable materials. In the method of Patent Document 5, the treatment of hydrogen fluoride of exhaust gas generated during roasting becomes a problem.

JP 2012-204000 A JP 2013-187142 A JP 2005-197149 A JP 2014-227565 A Japanese Patent No. 3079285

  The present invention is a process for promoting the fixation of generated hydrogen fluoride and reducing the amount of hydrogen fluoride transferred to exhaust gas by returning fine particles after thermal decomposition of the lithium ion battery to the thermal decomposition step. The present invention relates to a method and a processing apparatus.

The processing method, processed product, and processing apparatus of the present invention have the following configurations.
[1] The process of thermally decomposing a lithium ion battery, the process of crushing the pyrolyzed product, the process of separating the crushed product into fine particles and coarse particles, and returning the separated fine particles to the above pyrolysis step In the thermal decomposition step, lithium carbonate contained in the returned fine particles is reacted with hydrogen fluoride generated by thermal decomposition of the fluorine compound contained in the battery to produce lithium fluoride. And reducing the concentration of hydrogen fluoride in the exhaust gas.
[2] (a) In the pyrolysis step, the lithium-containing active material, the organic fluorine compound and the fluorine-containing lithium compound in the electrolyte contained in the electrode are pyrolyzed, and (b) in the crushing, the pyrolyzate is crushed, (C) In the fractionation step, the coarse particles containing the crushed metal and the fine particles containing the active material and the thermal decomposition product of the electrolyte solution are separated, and (d) the fine particles are decomposed in the return step. Returning to the process, (e) Lithium carbonate, which is the pyrolyzate contained in the returned fine particles, is reacted with hydrogen fluoride produced by pyrolysis of the fluorine compound contained in the battery to produce lithium fluoride. The method for treating a lithium ion battery according to the above [1], wherein the concentration of hydrogen fluoride in the exhaust gas is reduced.
[3] Described in [1] or [2] above, the amount of fine particles returned to the pyrolysis step is 0.35 to 1.0 times the amount of lithium ion battery to be pyrolyzed. A method for treating a lithium ion battery.
[4] The method for treating a lithium ion battery according to any one of [1] to [3] above, wherein the thermal decomposition step is a non-oxidizing atmosphere.
[5] The method for treating a lithium ion battery according to any one of [1] to [4] above, wherein the heating temperature in the pyrolysis step is 400 ° C to 600 ° C.
[6] The method for treating a lithium ion battery according to any one of [1] to [5] above, wherein a fine granule having a lithium carbonate concentration of 4.0 wt% or less is extracted out of the system.
[7]
Pyrolysis means for pyrolyzing lithium ion batteries, means for crushing pyrolyzed batteries, means for separating crushed materials into coarse particles and fine particles, means for returning sorted fine particles to the pyrolysis means, heat A thermal decomposition treatment apparatus for a lithium ion battery, characterized in that it has a means for extracting a cracked product from the system.

[Specific description]
The treatment method of the present invention includes a step of thermally decomposing a lithium ion battery, a step of crushing the pyrolyzed product, a step of separating the crushed product into fine particles and coarse particles, and the pyrolysis of the separated fine particles. A return step for returning to the process, and in the thermal decomposition step, the lithium salt contained in the returned fine particles and the hydrogen fluoride generated by the thermal decomposition of the fluorine compound contained in the battery are reacted and stabilized. This is a method for thermal decomposition treatment of a lithium ion battery, characterized in that the concentration of hydrogen fluoride in exhaust gas is reduced by generating an appropriate lithium fluoride.

  An outline of the treatment method according to the present invention is shown in the process diagram of FIG. The processing method of the present invention illustrated in FIG. 1 includes a thermal decomposition step, a crushing step, a separation step, a return step, and a recovery step of a lithium ion battery (LIB). Hereinafter, each processing step will be described.

[Lithium ion battery]
The positive electrode of the lithium ion battery (LIB) contains an active material such as lithium cobaltate, lithium nickelate, or lithium manganate. In the present invention, these lithium compounds are referred to as lithium-containing active materials. The negative electrode contains a negative electrode active material such as graphite and lithium titanate. These active materials are fixed to a current collector made of copper foil or aluminum foil with a binder made of an organic fluorine compound such as polyvinylidene fluoride (PVDF). In addition, an electrolytic solution in which an electrolyte such as lithium hexafluorophosphate (LiPF ₆ ) or lithium tetrafluoroborate (LiBF ₄ ) is dissolved in an organic solvent such as carbonates is mainly used. In the present invention, electrolytes such as lithium hexafluorophosphate and lithium tetrafluoroborate are referred to as fluorine-containing lithium compounds.

[Pyrolysis process]
The lithium ion battery is put in a pyrolysis furnace, and preferably heated at 400 ° C. to 600 ° C. in a non-oxidizing atmosphere such as a superheated steam atmosphere or an inert gas atmosphere for 0.5 to 4.0 hours. Is pyrolyzed. The flammable electrolyte can be rendered harmless by thermal decomposition, and the volume can be reduced by treating flammables such as separators and adhesive resins. The decomposition temperature of the electrolyte fluorine-containing lithium compound is about 200 ° C., but the decomposition temperature of the organic fluorine compound binder contained in the electrode is about 400 ° C., so the heating temperature needs to be 400 ° C. or higher. On the other hand, since the aluminum foil of the current collector melts when the heating temperature exceeds the melting point of aluminum (about 660 ° C.), it becomes difficult to crush and separate, so the heating temperature is preferably 600 ° C. or less.

  In the thermal decomposition step, the organic fluorine compound is thermally decomposed to generate hydrogen fluoride, and the fluorine-containing lithium compound such as lithium hexafluorophosphate of the electrolyte is thermally decomposed to generate hydrogen fluoride and phosphoric acid.

The generated hydrogen fluoride and the lithium-containing active material contained in the electrode, specifically, for example, lithium cobaltate (LiCoO ₂ ), lithium nickelate (LiNiO ₂ ), lithium manganate (LiMn ₂ O ₄ ), etc. Then, reaction is performed as in the following formulas (1) to (3), and a metal oxide such as MnO, NiO, and CoO and lithium fluoride (LiF) are generated.

4LiCoO ₂ + 4HF + C → 4CoO + 4LiF + CO ₂ + 2H ₂ O (1)
4LiNiO ₂ + 4HF + C → 4NiO + 4LiF + CO ₂ + 2H ₂ O (2)
4LiMn ₂ O ₄ + 4HF + 3C → 8MnO + 4LiF + 3CO ₂ + 2H ₂ O Formula (3)

Phosphoric acid generated by thermal decomposition also reacts with the lithium-containing active material to produce MnO, NiO, CoO, and lithium phosphate (Li ₃ PO ₄ ). Further, the formula (1) and CO ₂ produced by the reaction of to Formula (3), lithium-containing active material to produce a reaction to lithium carbonate (Li ₂ CO _3). As will be described later, this lithium carbonate is contained in the fine particles after the pulverization and separation, and is returned to the thermal decomposition process. As shown in the following formula (4), the lithium carbonate reacts with hydrogen fluoride to form lithium fluoride. Generate.
Li ₂ CO ₃ + 2HF → 2LiF + CO ₂ + H ₂ O Formula (4)

  Although it is quantitatively less than lithium carbonate, unreacted lithium cobaltate, lithium nickelate and lithium manganate remaining after the pyrolysis step are also included in the fine particles after crushing and fractionation. Also returned to the thermal decomposition step, lithium fluoride is generated by reacting with hydrogen fluoride again as shown in equations (1) to (3).

Even when lithium tetrafluoroborate (LiBF ₄ ) is used in the electrolytic solution, lithium tetrafluoroborate is thermally decomposed similarly to lithium hexafluorophosphate and causes a similar reaction.

  Thus, metal oxides such as MnO, NiO, CoO, lithium fluoride, lithium phosphate, lithium carbonate, etc. are obtained by thermal decomposition of the lithium-containing active material, the organic fluorine compound, and the fluorine-containing lithium compound contained in the lithium ion battery. Produces. Further, the pyrolyzate contains a copper foil or aluminum foil as a current collector, graphite as a negative electrode, and the like. This pyrolyzate is sent to the crushing process.

[Crushing process]
In the crushing step, the thermal decomposition product of the lithium ion battery is crushed. In general, the current collector of the positive electrode is high-purity aluminum, and the current collector of the negative electrode is high-purity copper, and each current collector is a sheet or foil having a thickness of about 10 to 20 μm. Since these sheet or foil current collectors are malleable, they become roughly 1 mm or more coarse particles. On the other hand, since the active material adhering to the current collector is an aggregate of particles of about 1 to 50 μm, it can be finely crushed into fine crushed material of less than about 1 mm. Any crushing means may be used as long as the pyrolyzate can be crushed into the coarse particles and the fine particles.

[Separation process]
The crushed material is sieved into fine particles of approximately less than 1 mm, preferably 0.5 mm or less, and coarse particles larger than this. Sifting may be performed using a vibrating sieve having a mesh size of 0.1 mm to 1.0 mm, preferably 0.1 mm to 0.5 mm. By this separation, the metal foil of the current collector contained in the coarse particles and the pyrolyzate of the active material contained in the fine particles can be separated. For example, 90 wt% to 99.5 wt% of the active material pyrolysis product of the positive electrode and the negative electrode is contained in the fine particles. On the other hand, the crushed material of the current collector is included in the coarse particles.

[Return process]
The separated fine particles are returned to the pyrolysis step in the return step. Further, since the exhaust gas generated in the thermal decomposition process contains a large amount of soot, it is preferable that the exhaust gas is guided to the soot recovery process to recover soot. Since the dust contains fine particles, the fine particles are also returned to the pyrolysis process together with the separated fine particles.

  The gas generated by the thermal decomposition of the lithium carbonate of the fine particles and the fluorine compound contained in the lithium ion electrode (the organic fluorine compound contained in the electrode and the fluorine-containing lithium compound of the electrolytic solution) by returning the fine particles. Lithium fluoride can be produced by reacting hydrogen fluoride therein. Further, by returning the fine particles, lithium fluoride can be reacted with lithium cobaltate, lithium nickelate, lithium manganate and the like remaining in the fine particles to generate lithium fluoride.

  By returning the fine particles, hydrogen fluoride becomes lithium fluoride, the amount immobilized is increased, and the amount of hydrogen fluoride transferred to the exhaust gas can be reduced. For example, when the fine particles are not returned to the pyrolysis step, the amount of hydrogen fluoride transferred to the exhaust gas is approximately 5.0 to 40.0 wt% of the amount of fluorine originally contained in the battery. Is reduced to approximately 0.1 to 2.0 wt% by returning to the pyrolysis step.

  The weight of the fine particles returned to the pyrolysis step is preferably 0.35 to 1.0 times the weight of the lithium ion battery to be pyrolyzed. If the weight of the fine particles is less than 0.35 times, the fixation of hydrogen fluoride becomes insufficient, and the effect of suppressing the amount of hydrogen fluoride transferred to the exhaust gas is not sufficient. On the other hand, if the weight of the fine particles exceeds 1.0 times, the dust concentration of the exhaust gas becomes excessive, and the load of the exhaust gas treatment increases.

  By repeating the return of the fine particles, the amount of lithium fluoride contained in the fine particles gradually increases. When the fine particles are not returned to the pyrolysis step, the amount of lithium fluoride contained in the fine particles is approximately 6.0 to 7.5 wt%, but by returning the fine particles to the pyrolysis step, The amount of lithium fluoride contained in the fine particles after pyrolysis generally increases to 8.0 to 10.0 wt%.

  On the other hand, the content of lithium carbonate in the fine particles gradually decreases. When the fine particles are not returned to the pyrolysis step, the amount of lithium carbonate contained in the fine particles is approximately 5.5 to 7.0 wt%, but by returning the fine particles to the pyrolysis step, The amount of lithium carbonate contained in the fine granules after pyrolysis is reduced to approximately 3.0 to 5.0 wt%.

[Recovery process]
Since the separated coarse particles contain metal foil as a current collector, the coarse particles are extracted out of the system and sorted into specific materials such as lightweight aluminum based and heavy copper based by specific gravity sorting. Aluminum and copper can be recovered.

The separated fine particles are returned to the pyrolysis step, and lithium carbonate contained in the fine particles is used for pyrolysis, but the concentration of lithium carbonate contained in the fine particles is approximately 4.0 wt% or less. The particulate matter is extracted out of the system because the effect of suppressing the amount of hydrogen fluoride transferred to the exhaust gas is not sufficient. For the fixation of hydrogen fluoride, lithium cobaltate, lithium nickelate, lithium manganate, etc. in fine particles returned to the thermal decomposition process are also used, but the quantity is small compared to the lithium carbonate concentration. Therefore, only the lithium carbonate concentration can be used as a criterion for extraction.
Since the fine particles contain metal oxides such as MnO, NiO, and CoO generated by thermal decomposition of the lithium-containing active material together with the above lithium carbonate, lithium phosphate, lithium fluoride, etc., they were extracted out of the system. Fine particles can be sent to the metal recovery process to recover rare metals such as manganese, nickel, cobalt, and lithium.

[Pyrolysis treatment equipment]
An outline of the thermal decomposition treatment apparatus of the present invention is shown in FIG. As shown in the figure, a thermal decomposition treatment apparatus 10 according to the present invention includes a thermal decomposition means 11 for thermally decomposing a lithium ion battery, a means 12 for crushing a thermally decomposed battery, and a crushed material is separated into coarse particles and fine particles. Means 13; means 14 for returning the separated fine particles to the thermal decomposition means; and means 16 for extracting the fine particles having a lithium carbonate concentration of a certain concentration or less from the system.

  The thermal decomposition means 11 is means for thermally decomposing a lithium ion battery at 400 ° C. to 600 ° C. in a non-oxidizing atmosphere such as a superheated steam atmosphere or an inert gas atmosphere, and uses a closed heating furnace such as a rotary kiln. be able to. A crushing means 12 is connected to the thermal decomposition means 11. The crushing means 12 is a means for crushing the pyrolyzed product to a particle diameter of about 1 mm, and a biaxial crusher, a chain crusher, a hammer crusher, a roll mill, a cutter mill, or the like can be used. A separating means 13 is connected to the crushing means 12. The separating means 13 is a means for separating the crushed material into fine particles having a particle diameter of 1 mm or less and coarse particles having a particle diameter larger than this, and a vibrating sieve or the like can be used.

  A return means 14 is connected to the sorting means 13. The return means 14 is a means for returning the fine particles to the thermal decomposition means 11, and the return means 14 is provided with a return pipeline 15 from the fine particle reservoir 13 A of the sorting means 13 to the thermal decomposition means 11. The return pipe 15 is provided with means 16 for extracting fine particles having a lithium carbonate concentration of a certain concentration or less out of the system. The coarse particle reservoir 13B of the sorting means 13 is provided with means 17 for extracting the coarse particles out of the system. If necessary, the extraction means 16 is connected to a refining process for recovering rare metals, and the extraction means 17 is connected to a specific gravity selection process or the like.

  In the illustrated apparatus, a dust collection means 18 is provided in the exhaust system of the thermal decomposition means 11. For example, a cyclone or a bag filter can be used as the dust collection means 18. The fine particles contained in the exhaust gas are collected by the dust collection means 18. The collected fine particles are sent to the fine particle reservoir 13A. The dust collection means 18 may be provided as necessary.

  In the treatment method of the present invention, the pulverized fine particles contain lithium carbonate produced by thermal decomposition of a lithium ion battery, and lithium cobaltate, lithium nickelate, lithium manganate, etc. remaining in the thermal decomposition step. Using this, the crushed fine particles are returned to the pyrolysis step, hydrogen fluoride generated in the pyrolysis step, lithium carbonate contained in the crushed fine particles, and lithium cobaltate and nickel acid remaining in the pyrolysis step Since fluorine is fixed by reacting lithium, lithium manganate or the like to generate lithium fluoride, the concentration of hydrogen fluoride in the exhaust gas can be greatly reduced.

  Since the concentration of hydrogen fluoride in the exhaust gas is obliged to be below a certain level by environmental regulations, the exhaust gas containing hydrogen fluoride absorbs hydrogen fluoride with a scrubber or the like, and further contains fluorine from the scrubber wastewater. Need to be removed. For this reason, when the fluorine load of exhaust gas is high, the burden of the scrubber equipment and the water treatment equipment increases, and the treatment cost increases. On the other hand, the treatment method of the present invention can greatly reduce the burden of exhaust gas treatment because the amount of hydrogen fluoride in the exhaust gas is small.

  Furthermore, in the treatment method of the present invention, since fluorine is fixed using lithium carbonate generated by thermal decomposition, it is not necessary to add a fluorine fixing agent such as calcium salt from the outside of the system. Therefore, it is possible to efficiently concentrate the rare metal component without increasing unnecessary impurities in the thermal decomposition residue. Therefore, the purification and recovery of the rare metal is facilitated, and the processing cost can be suppressed.

The process drawing of the processing method concerning the present invention. The conceptual diagram of the processing apparatus which concerns on this invention.

[Example 1]
A used lithium ion battery (LIB) (weight: 3.18 kg, fluorine content: 100.5 g) was put into a batch type rotary kiln and subjected to thermal decomposition in the atmosphere shown in Table 1 by heating at a heating temperature for 1 hour. The temperature was raised from room temperature at a rate of 10 ° C./min, maintained at the temperature shown in Table 1 for 1 hour, and then cooled. The pyrolyzate was crushed and separated into fine particles having an average particle size of 0.5 mm or less and coarse particles having a larger particle size. The fine particles were collected and returned to the rotary kiln, and again thermally decomposed. The fine particles were returned five times, and the substances contained in the collected fine particles were examined by XRD. Mn, Ni, Co oxide derived from the positive electrode active material, graphite as the negative electrode active material, lithium fluoride, They were lithium phosphate and lithium carbonate. Table 1 shows the amount of each return. This return amount is the weight ratio of the return fine particles to the input amount of the lithium ion battery. Table 1 shows the amount of lithium fluoride, the amount of lithium phosphate and the amount of lithium carbonate contained in the fine particles after the completion of the return five times. Further, the amount of hydrogen fluoride contained in the exhaust gas until the end of the fifth return was measured. The exhaust gas was condensed with a water-sealed bubbler, and the fluorine concentration in the bubbler liquid was analyzed to calculate the amount of hydrogen fluoride in the exhaust gas. A predetermined amount (25.0 kg) of ion-exchanged water was put in a water-sealed bubbler before the test. The results are shown in Table 1.

As shown in Table 1, Samples No. 1 to No. 3 have a non-oxidizing atmosphere, a heating temperature of 400 ° C. to 600 ° C., a fine particle return amount of 0.35 to 1.0 times, and a return of 5 times. After completion, the fine-grained product has a lithium fluoride content of 8.1 to 8.4 wt% and a lithium carbonate content of 4.2 to 4.3 wt%, compared with Comparative Example 1 in which the fine-grained product is not returned. A lot of lithium fluoride and a little lithium carbonate. Further, the amount of hydrogen fluoride contained in the exhaust gas is 0.2 to 0.3 wt%, and the amount of hydrogen fluoride contained in the exhaust gas is significantly smaller than that of Comparative Example 1 in which the fine particles are not returned.
Sample No. 4 with a small amount of fine particles returned has a low lithium fluoride content of 7.5 wt% after completion of the return five times, and the amount of hydrogen fluoride contained in the exhaust gas increases. Since there is a tendency, the return amount of the fine particles is preferably 0.35 to 1.0 times.

[Example 2]
A used lithium ion battery (weight: 3.18 kg, fluorine content: 100.5 g) is put into a batch rotary kiln, and is pyrolyzed by heating at 500 ° C. for 1 hour in a superheated steam atmosphere, and the pyrolyzed product is crushed. The fine particles having an average particle diameter of 0.5 mm or less and the coarse particles having a larger particle diameter were fractionated, and the fine particles were recovered and returned to the rotary kiln, and again thermally decomposed. Table 2 shows the amount of fine particles returned and the number of returns. Table 2 shows the amount of lithium fluoride, the amount of lithium phosphate and the amount of lithium carbonate contained in the fine particles after the return of the fine particles and the amount of hydrogen fluoride contained in the exhaust gas until the completion of the return.

  As shown in Table 2, the more the fine particles are returned, the more the amount of lithium fluoride and lithium phosphate contained in the fine particles after the return is increased, and the amount of lithium carbonate is decreased. In response to this, the amount of hydrogen fluoride contained in the exhaust gas has decreased.

[Comparative Example 1]
A batch type rotary kiln was charged with a used lithium ion battery (weight 3.18 kg, fluorine content 100.5 g), and pyrolyzed at 500 ° C. in a superheated steam atmosphere. The temperature was raised from room temperature at a rate of 100 ° C./min, held at 500 ° C. for 1 hour, and then cooled. The amount of hydrogen fluoride in the exhaust gas was measured in the same manner as in Example 1. The weight of the lithium ion battery after the test was 2.40 kg, and the amount of liquid in the water-sealed bubbler was 29.2 kg. Since the specific gravity of the water-sealed bubbler liquid was 1.00 g / mL, the fluorine concentration in the exhaust gas was 320 mg / L. The amount of hydrogen fluoride calculated from this fluorine concentration was 10.1 g, and the amount of fluorine in the exhaust gas was 10.0%, assuming that the amount of fluorine contained in the lithium ion battery was 100%.

  The treatment method and treatment apparatus of the present invention can be suitably used for the treatment business of used lithium ion batteries.

10-Pyrolysis treatment device, 11-Pyrolysis means, 12-Fracture means, 13-Fractionation means, 13A-Fine grain reservoir, 13B-Coarse grain reservoir, 14-Return means, 15-Return line, 16- Extraction means, 17-extraction means, 18-dust collection means.

Claims (7)

  A step of pyrolyzing the lithium ion battery, a step of crushing the pyrolyzed product, a step of separating the crushed product into fine particles and coarse particles, and a returning step of returning the sorted fine particles to the above pyrolysis step. In the thermal decomposition step, lithium carbonate contained in the returned fine particles is reacted with hydrogen fluoride generated by thermal decomposition of the fluorine compound contained in the battery to produce lithium fluoride, A method for thermally decomposing a lithium ion battery, comprising reducing the hydrogen fluoride concentration of exhaust gas.   (A) In the thermal decomposition step, the lithium-containing active material, the organic fluorine compound and the fluorine-containing lithium compound in the electrolyte contained in the electrode are thermally decomposed. In the separation step, the coarse particles containing the crushed metal and the fine particles containing the pyrolyzate of the active material and the electrolytic solution are separated. (E) Lithium carbonate, which is a pyrolyzate contained in the returned fine particles, is reacted with hydrogen fluoride generated by the pyrolysis of the fluorine compound contained in the battery to produce lithium fluoride, thereby generating exhaust gas. The method for treating a lithium ion battery according to claim 1, wherein the concentration of hydrogen fluoride is reduced.   The treatment of the lithium ion battery according to claim 1 or 2, wherein the return amount of the fine particles returned to the pyrolysis step is 0.35 to 1.0 times the amount of the lithium ion battery to be pyrolyzed. Method.   The method for treating a lithium ion battery according to any one of claims 1 to 3, wherein the thermal decomposition step is a non-oxidizing atmosphere.   The processing temperature of the lithium ion battery according to any one of claims 1 to 4, wherein a heating temperature in the pyrolysis step is 400 ° C to 600 ° C.   The method for treating a lithium ion battery according to any one of claims 1 to 5, wherein fine particles having a lithium carbonate concentration of 4.0 wt% or less contained in the fine particles are extracted from the system. Pyrolysis means for pyrolyzing lithium ion batteries, means for crushing pyrolyzed batteries, means for separating crushed materials into coarse particles and fine particles, means for returning sorted fine particles to the pyrolysis means, heat A thermal decomposition treatment apparatus for a lithium ion battery, characterized in that it has a means for extracting a cracked product from the system.

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