JP2013120709A - Disposal method for waste battery material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a disposal method for waste battery materials which is capable of treating waste battery materials at a low temperature and is capable of providing a high treatment speed.SOLUTION: The disposal method for waste battery materials of the present invention includes an addition step of adding an alkali metal compound to waste battery materials having shapes passing through a mesh with openings of 10 mm, and a heating step of heating a mixture of the waste battery materials and the alkali metal compound.

Description

 The present invention relates to a battery waste material disposal method.

 Lithium-ion secondary batteries have higher operating voltage, better charge / discharge cycles, and higher energy density than conventional secondary batteries, so power supplies for communication and information devices such as mobile phones, laptop computers, and digital cameras As a large-sized secondary battery that serves as a power source for automobiles.

 The active material of the battery contains rare metal components such as cobalt, nickel, manganese, and lithium. In particular, the positive electrode active material of the non-aqueous electrolyte secondary battery has the rare metal component as a main component. A compound has been used. Also, copper is used for the negative electrode current collector. In order to preserve the resources of the rare metal component, a method for recovering the rare metal component from the battery waste material of the secondary battery is required.

Generally, a method for treating a waste lithium ion secondary battery by a roasting process (for example, see Patent Document 1), a leaching process (for example, see Patent Document 2), or the like has been proposed.
As a member constituting the lithium ion secondary battery, a positive electrode, a negative electrode, a separator, an electrolytic solution and the like are mainly used. Inside the battery, a positive electrode and a negative electrode are placed opposite to each other with a separator interposed therebetween, and the electrolyte solution penetrates into these members and is accommodated in the casing.

In the positive electrode, a mixture of a positive electrode active material, a conductive material made of a carbon material, and a binder made of a fluorine-containing resin such as polyvinylidene fluoride (hereinafter referred to as “PVdF”) is used as an aluminum foil current collector. It has a coated structure.
The negative electrode has a structure in which a mixture of a negative electrode active material made of a carbon material and a binder made of a resin such as a styrene-butadiene copolymer (hereinafter referred to as “SBR”) is applied to a copper current collector. There is no.
The separator is made of an olefin resin such as porous polyethylene or polypropylene.
The electrolytic solution is a solution in which a lithium salt as an electrolyte is dissolved in a solvent of an organic carbonate such as ethylene carbonate.

 In order to recycle a rare metal component from a battery, it is necessary to separate an active material or copper foil containing a rare metal component such as cobalt, nickel, manganese, or lithium from a battery waste material. Battery waste contains flammable substances that are difficult to recycle. Examples of the combustible material include a carbon material contained in the negative electrode active material and the current collector, and a resin contained in the binder and the separator. In recycling rare metal components, it is required to separate carbon materials and resins that are flammable substances from rare metal components and to dispose of carbon materials and resins that are flammable substances. As a method for treating a flammable substance, a method for incinerating a flammable substance is disclosed (for example, see Patent Document 3).

However, in the incineration of a carbon material used as a negative electrode active material or a conductive material, or a resin used as a binder or a separator, a high temperature is required to increase the processing speed. However, the disposal process at a high temperature has the disadvantage that a great amount of energy is consumed for heating and the deterioration of the incinerator is accelerated.
In particular, when the battery waste material contains a carbon material, the processing speed is slow, and a high temperature is required for the processing. Further, when the carbon material is graphite, the processing speed is further reduced, and a higher temperature is required for the processing.
Therefore, in the disposal of battery waste materials, there is a need for a method for disposal of battery waste materials that can be processed at a relatively low temperature and can obtain a high processing speed.

Japanese Patent No. 3257854 Japanese Patent No. 3676926 Japanese Patent No. 449185 gazette

 This invention is made | formed in view of the said situation, and makes it a subject to provide the disposal processing method of the battery waste material which can process a battery waste material at low temperature, and a high processing speed is obtained.

 In order to solve the above-mentioned problems, the battery waste material disposal method of the present invention includes an addition step of adding an alkali metal compound to a battery waste material having a shape passing through a mesh having an opening of 10 mm, the battery waste material, and the alkali metal compound. And a heating step of heating the mixture.

 The battery waste material disposal method according to the present invention may include a crushing step in which the battery waste material is shaped to pass through a mesh having an opening of 10 mm.

 In the battery waste material disposal method of the present invention, the battery waste material may contain a carbon material.

 In the battery waste material disposal method of the present invention, the carbon material may contain graphite.

In the battery waste material disposal method according to the present invention, the carbon material preferably has a specific surface area of 0.1 to ²⁰ m ² / g.

 In the battery waste material disposal method of the present invention, it is preferable that the holding temperature in the heating step is equal to or higher than a temperature lower by 100 ° C. than the melting start temperature of the alkali metal compound.

 In the battery waste material disposal method of the present invention, it is preferable that a holding temperature in the heating step is equal to or higher than a melting temperature of the alkali metal compound.

 In the battery waste material disposal method of the present invention, it is preferable that the alkali metal compound is an oxidizing alkali metal compound having an oxidizing power to oxidatively decompose the carbon material at the holding temperature in the heating step.

 In the battery waste material disposal method of the present invention, the oxidizing alkali metal compound is an alkali metal peroxide, an alkali metal superoxide, an alkali metal nitrate, an alkali metal hydrochloride, or an alkali metal vanadate. It is preferably at least one selected from the group consisting of a salt and an alkali metal molybdate.

 In the battery waste material disposal method of the present invention, it is preferable that the alkali metal compound is alkaline when dissolved in water.

 In the battery waste material disposal method of the present invention, the alkaline alkali metal compound is an alkali metal hydroxide, an alkali metal carbonate, an alkali metal hydrogencarbonate, an alkali metal oxide, or an alkali metal superoxide. It is preferably at least one selected from the group consisting of products.

 According to the battery waste material disposal method of the present invention, the battery waste material can be treated at a lower temperature than before, and a high treatment speed can be obtained.

And oxidizing power required to oxidize the carbon is a diagram showing the temperature dependence of the oxygen potential showing the relationship between the oxidizing power alkali metal compound (sodium compound) has (log [P (O 2) ]. Shows the temperature dependence of oxygen potential (log [P (O ₂ )]) indicating the relationship between the oxidizing power required to oxidize carbon and the oxidizing power of alkali metal compounds (peroxides, superoxides) FIG. And oxidizing power required to oxidize the carbon, which is a diagram showing the temperature dependence of the alkali metal compound oxygen potential showing the relationship between the oxidizing power (sulfate) has (log [P (O 2) ].

Hereinafter, an embodiment of a method for disposing of waste battery materials according to the present invention will be described.
Note that this embodiment is specifically described in order to better understand the gist of the invention, and does not limit the present invention unless otherwise specified.

 The battery waste material disposal method of the present invention is a method including an addition step and a heating step.

<Addition process>
The adding step is a step of adding an alkali metal compound to the battery waste material having a shape passing through a mesh having an opening of 10 mm.

"Mixing of battery waste and alkali metal compounds"
In the adding step, it is preferable to add the alkali metal compound to the battery waste and then mix them.

(mixture)
The method of mixing the battery waste material and the alkali metal compound may be either dry mixing or wet mixing, or a combination thereof. The order in which dry mixing and wet mixing are performed is not particularly limited.
When mixing the battery waste material and the alkali metal compound, it is preferable to go through a step of pulverizing and mixing the battery waste material and the alkali metal compound using a mixing device equipped with a mixing medium such as a ball. Thereby, the mixing efficiency of a battery waste material and an alkali metal compound can be improved.

Dry mixing is preferable because the battery waste material and the alkali metal compound can be more easily mixed. In dry mixing, a V-type mixer, a W-type mixer, a ribbon mixer, a drum mixer, a powder mixer equipped with a stirring blade, a ball mill, a vibration mill, or a combination of these devices can be used. .
It is possible to efficiently mix the battery waste material and the alkali metal compound by performing a process of crushing or cutting a relatively large battery waste material in advance to make the battery waste material into a shape that passes through a mesh with an opening of 10 mm. it can. Thereby, the high processing speed which is the effect acquired by adding an alkali metal compound to battery waste material is realizable.

"Battery waste"
In the present invention, the “battery waste material” is waste generated in the process of discarding the battery or the process of manufacturing the battery, and includes a combustible substance that is oxidatively decomposed by heating in air.
Examples of the battery waste include, for example, used batteries and non-standard batteries, and battery members including any of these constituent materials, such as positive electrodes, negative electrodes, separators, electrolytes, and battery components generated by disassembly of the batteries, Examples thereof include an electrode end portion and an extra electrode mixture generated in the battery manufacturing process, and a nonstandard electrode or electrode mixture which is not suitable for battery manufacturing.
In the present invention, a relatively large battery waste such as an electrode or a separator is previously subjected to a crushing step for crushing, cutting, pulverizing, etc., so that the battery waste is finely divided and passing through a mesh having an opening of 10 mm. Battery waste material that has been refined to a minimum is used.

(Flammable substances)
A combustible substance is a substance that is oxidatively decomposed by heating in air.
Examples of combustible substances contained in battery waste include carbon materials that constitute negative electrodes and conductive materials, and resins that constitute binders and separators.

(Carbon material)
Specific examples of carbon materials contained in battery waste include graphite such as natural graphite and artificial graphite, cokes, carbon black (for example, acetylene black), pyrolytic carbons, and fibrous carbon materials (for example, graphitization). Carbon fiber, carbon nanotube) and organic polymer compound fired body. Note that the carbon material contained in the battery waste material may be a single carbon material or may be composed of a plurality of carbon materials.

 Among combustible substances, it is a carbon material that has a low processing speed and requires a high temperature in the processing. The carbon material is included in the battery waste as a negative electrode active material or a conductive material. In the case where a carbon material is included as a combustible substance, the present invention can exhibit the effect of lowering the processing temperature and the effect of increasing the processing speed.

 In particular, among carbon materials, when processing graphite, the processing speed is low and a high processing temperature is required. Graphite is contained in battery waste as a negative electrode active material or conductive material. In the present invention, when graphite is included as a combustible substance, the effect of lowering the processing temperature and the effect of increasing the processing speed can be exhibited.

The specific surface area of the carbon material to which the present invention is applied is usually 0.01 to 2000 m ² / g. The present invention can be preferably applied to a carbon material having a specific surface area of 0.1 to ²⁰ m ² / g.
In the present invention, the specific surface area is measured as a BET specific surface area using nitrogen gas.
In the present invention, the particle diameter of the carbon material is not particularly limited. Usually, the particle diameter of the carbon material contained in the battery waste is about 0.001 to 100 μm. In addition, the particle diameter of the primary particle of a carbon material can be measured with an electron micrograph.
Moreover, the processing speed of a carbon material can be raised by using the alkaline alkali metal compound and oxidizing alkali metal compound which are mentioned later. Furthermore, even a carbon material having a small specific surface area can be oxidized.

(resin)
An example of the resin contained in the battery waste material is a thermoplastic resin used as a binder.
Specific examples of the thermoplastic resin include polyvinylidene fluoride (PVdF), polytetrafluoroethylene (hereinafter sometimes referred to as “PTFE”), tetrafluoroethylene, hexafluoropropylene, and vinylidene fluoride. Fluoropolymers such as copolymers, propylene hexafluoride / vinylidene fluoride copolymers and tetrafluoroethylene / perfluorovinyl ether copolymers; polyolefin resins such as polyethylene and polypropylene; styrene-butadiene copolymers (hereinafter referred to as “polyethylene resins”) , “SBR”)); These thermoplastic resins are used alone or in combination of two or more.

 Examples of other resins contained in battery waste include porous membranes, nonwoven fabrics, and woven fabrics made of materials such as polyolefin resins such as polyethylene and polypropylene used as separators, fluororesins, and nitrogen-containing aromatic polymers. The material which has the form of etc. is mentioned. These materials are used alone or in combination of two or more.

"Alkali metal compounds"
The alkali metal compound is composed of one or more compounds.
An alkali metal compound can improve a processing speed by contacting with the combustible substance contained in a battery waste material. In particular, the effect of improving the processing speed is enhanced by the alkali metal compound containing the molten part coming into contact with the active material.
Furthermore, the alkali metal compound stabilizes the fluorine component as an alkali metal fluoride by contacting with a binder contained in the battery waste material or a compound containing fluorine derived from the electrolytic solution, and corrosive gas such as hydrogen fluoride. It plays a role in preventing the occurrence of.

The amount of the alkali metal compound added is preferably 0.001 to 100 times, more preferably 0.05 to 1 time, based on the weight of the flammable substance.
By appropriately controlling the addition amount of the alkali metal compound, it is possible to reduce the cost for disposal of the battery waste material and increase the processing speed of the combustible substance. Moreover, it can play a role of preventing the generation of corrosive gas such as hydrogen fluoride.

Furthermore, in addition to the alkali metal compound, a compound other than the alkali metal compound may be added to the battery waste material.
Examples of the compound other than the alkali metal compound include an alkaline earth metal compound containing an alkaline earth metal element such as magnesium, calcium, and barium.
Alkaline earth metal compounds are used together with alkaline metal compounds in order to control the melting start temperature of the mixture of battery waste materials and alkaline metal compounds and to prevent the generation of corrosive gases such as hydrogen fluoride. Mixed.

Examples of alkali metal compounds include alkali metal hydroxides, alkali metal borates, alkali metal carbonates, alkali metal oxides, alkali metal peroxides, alkali metal superoxides, and alkali metal nitrates. , Alkali metal phosphate, alkali metal sulfate, alkali metal chloride, alkali metal vanadate, alkali metal carbonate, alkali metal molybdate, alkali metal tungstate, etc. . These compounds are used alone or in combination of two or more as a component of the alkali metal compound mixed in the battery waste material.
The alkali metal element constituting the alkali metal compound is not particularly limited as long as it is an alkali metal element, but lithium, sodium and potassium are preferable. In addition, when 2 or more types of alkali metal compounds are contained as a component of an activation processing agent, the alkali metal compound containing a different alkali metal element may be sufficient.

Specific examples of suitable alkali metal compounds include hydroxides such as LiOH, NaOH, KOH, RbOH, and CsOH; borides such as LiBO ₂ , NaBO ₂ , KBO ₂ , RbBO ₂ , and CsBO ₂ ; Li ₂ CO _{3 , Na 2 CO 3, K 2} CO 3, RbCO 3, carbonates such as _{CsCO 3; Li 2 O, Na} 2 O, K 2 O, Rb 2 O, an oxide such as _{Cs 2 O; Li 2 O 2} , _{Na 2 O 2, K 2 O} 2, Rb 2 O 2, Cs 2 peroxides such as _{O 2; LiO 2, NaO 2} , KO 2, superoxide such _{RbO 2, CsO 2; LiNO 3} , NaNO 3 _{, KNO 3, RbNO 3, CsNO} 3 nitrates such _{as; Li 3 PO 4, Na 3} PO 4, K 3 PO 4, Rb 3 PO 4, phosphate salts such as _Cs 3 PO _4; Li ₂ Sulfates such as SO ₄ , Na ₂ SO ₄ , K ₂ SO ₄ , Rb ₂ SO ₄ , Cs ₂ SO ₄ ; Chlorides such as LiCl, NaCl, KCl, RbCl, CsCl; LiBr, NaBr, KBr, RbBr, CsBr Bromides such as LiVO ₃ , NaVO ₃ , KVO ₃ , RbVO ₃ , CsVO ₃ and other vanadates; Li ₂ MoO ₄ , Na ₂ MoO ₄ , K ₂ MoO ₄ , Rb ₂ MoO ₄ , and CsMoO ₄ Salts; tungstates such as Li ₂ WO ₄ , Na ₂ WO ₄ , K ₂ WO ₄ , Rb ₂ WO ₄ , CsWO ₄ ;

(Oxidizing alkali metal compounds)
When the battery waste material contains a carbon material, at least one of the alkali metal compounds added to the battery waste material is an alkali metal compound (hereinafter referred to as “oxidizing power”) that oxidizes and decomposes the carbon material at the holding temperature in the heating step. It may be referred to as “oxidizing alkali metal compound”).
By using such an oxidizing alkali metal compound, it is possible to improve the processing speed at which the carbon material is oxidatively decomposed into carbon dioxide.

 Examples of alkali metal compounds having an oxidizing power necessary for oxidative decomposition of carbon materials into carbon dioxide include alkali metal peroxides, alkali metal superoxides, alkali metal nitrates, alkali metal sulfates, and alkalis. Examples thereof include metal vanadate and alkali metal molybdate. These compounds are used alone or in combination of two or more.

Specific examples of suitable oxidizing alkali metal compounds include peroxides such as Li ₂ O ₂ , Na ₂ O ₂ , K ₂ O ₂ , Rb ₂ O ₂ , Cs ₂ O ₂ ; LiO ₂ , NaO ₂ , Superoxides such as KO ₂ , RbO ₂ , CsO ₂ ; nitrates such as LiNO ₃ , NaNO ₃ , KNO ₃ , RbNO ₃ , CsNO ₃ ; Li ₂ SO ₄ , Na ₂ SO ₄ , K ₂ SO ₄ , Rb ₂ SO ₄ , sulfates such as Cs ₂ SO ₄ ; vanadates such as LiVO ₃ , NaVO ₃ , KVO ₃ , RbVO ₃ , CsVO ₃ ; Li ₂ MoO ₄ , Na ₂ MoO ₄ , K ₂ MoO ₄ , Rb ₂ MoO ₄ And molybdates such as CsMoO ₄ .

The oxidizing power for oxidatively decomposing the conductive material, which is a carbon material, into carbon dioxide and the oxidizing power of the activation treatment agent can be estimated using an oxygen potential (log [P (O ₂ )]).
The theory of these relationships is shown below.

(I) Oxidizing power necessary to oxidize carbon material The oxidizing power required to oxidize carbon to carbon dioxide will be described.
The equilibrium (a) for oxidizing carbon to carbon dioxide is considered as follows.

The equilibrium constant (K _{eq (a)} ) of equilibrium (a) has the relationship of the following formula (1).

The oxygen potential (log [P (O ₂ )]) of equilibrium (a) is given by the following formula (2).

 Here, it is the first term on the right side of the above equation (2).

Represents an oxygen potential peculiar to the redox system and is the second term on the right side of the above formula (2).

Represents a change in oxygen potential depending on the concentration of a substance involved in the redox system.
In comparing the oxygen potential (log [P (O ₂ )]) of various redox systems, it is the first term on the right side of the above formula (2).

Is the second term on the right side of equation (2),

Therefore, the influence on the change of the oxygen potential (log [P (O ₂ )]) is large. Therefore, the oxygen potential (log [P (O ₂ )]) in equilibrium (a) is represented only by log [K _{eq (a)} ] in the first term on the right side of the above equation (2).
That is, the oxygen potential (log [P (O ₂ )]) of equilibrium (a) is given by the following formula (3).

Here, log [K _{eq (a)} ] is calculated from the free energy change ΔrG _T ° [J / mol] of the reaction at a predetermined temperature T [° C.] by the following formula (4).

Here, R is a gas constant (8.314 [J / (K / mol)].
The free energy change ΔrG _T ° [J / mol] is calculated by the free energy of formation ΔfG _T ° at a predetermined temperature of the material involved in the reaction. In equilibrium (a), calculation is performed as shown in the following equation (5).

The free energy of formation ΔfG _T ° of each substance in the above formula (5) can be examined from a thermodynamic database. Further, the free energy of formation ΔfG _T ° can be calculated by thermodynamic calculation software. As the thermodynamic database and thermodynamic calculation software, for example, MALT2 (copyright holder: Japan Society for Thermometry, Publisher: Science and Technology Corporation) can be used.

(Ii) Oxidizing power of alkali metal compound As a calculation example of the oxidizing power of an alkali metal compound, a case where Na ₂ SO ₄ is contained as an alkali metal compound will be described.
When Na ₂ SO ₄ is contained as an alkali metal compound, a redox equilibrium of Na ₂ SO ₄ / Na ₂ S represented by the equilibrium (b) occurs.

The equilibrium constant (K _{eq (b)} ) of equilibrium (b) has the relationship of the following formula (6).

The oxygen potential (log [P (O ₂ )]) of Na ₂ SO ₄ / Na ₂ S is given by the following formula (7).

 Here, it is the first term on the right side of the above equation (7).

Represents an oxygen potential (log [P (O ₂ )]) peculiar to the redox system, and is the second term on the right side of the above formula (7).

Represents a change in oxygen potential (log [P (O ₂ )]) depending on the concentration of a substance involved in the redox system.
In comparing the oxygen potential (log [P (O ₂ )]) to various redox systems, it is the first term on the right side of the above formula (7).

Is the second term on the right side of equation (7),

Therefore, the influence on the change of the oxygen potential (log [P (O ₂ )]) is large. Therefore, the oxygen potential (log [P (O ₂ )]) of the redox equilibrium of Na ₂ SO ₄ / Na ₂ S is expressed only by the first term log [K _{eq (b)} ] on the right side of the above formula (7). .
That is, the oxygen potential (log [P (O ₂ )]) of Na ₂ SO ₄ / Na ₂ S is given by the following formula (8).

Here, log [K (Na ₂ SO ₄ / Na ₂ S)] is calculated from the free energy change ΔrG _T ° [J / mol] of the reaction at a predetermined temperature T [° C.].

 Here, R is a gas constant (8.314 [J / (K / mol)]).

Here, log [K _{eq (b)} ] is calculated using, for example, thermodynamic database software MALT2.

As an example of calculating the oxidizing power of an alkali metal compound, a case where Na ₂ O ₂ is contained as an alkali metal compound is shown.
When Na ₂ O ₂ is contained as the alkali metal compound, a redox equilibrium of Na ₂ O ₂ / Na ₂ CO ₃ represented by the equilibrium (c) occurs.

The equilibrium constant (K _{eq (c)} ) of the equilibrium (c) has the relationship of the following formula (11).

The oxygen potential (log [P (O ₂ )]) of Na ₂ O ₂ / Na ₂ CO ₃ is given by the following formula (12).

 Here, it is the first term on the right side of the above equation (12).

Represents an oxygen potential (log [P (O ₂ )]) peculiar to the redox system, and is the second term on the right side and the third term on the right side of the above formula (12).

Represents a change in oxygen potential (log [P (O ₂ )]) peculiar to the redox system.
In comparing the oxygen potential (log [P (O ₂ )]) to various redox systems, it is the first term on the right side of the above formula (12).

Is the second term on the right side of equation (2),

Therefore, the influence on the change of the oxygen potential (log [P (O ₂ )]) is large. Therefore, the oxygen potential (log [P (O ₂ )]) of redox equilibrium possessed by Na ₂ O ₂ / Na ₂ CO ₃ is determined only by the first term log [K _{eq (c)} ] on the right side of the above equation (12 ₎ . Represented by
That is, the oxygen potential (log [P (O ₂ )]) of Na ₂ O ₂ / Na ₂ CO ₃ is given by the following formula (13).

Here, log [K (Na ₂ O ₂ / Na ₂ CO ₃ )] is calculated from the free energy change ΔrG _T ° [J / mol] of the reaction at a predetermined temperature T [° C.].

 Here, R is a gas constant (8.314 [J / (K / mol)]).

Here, log [K _{eq (c)} ] is calculated using, for example, thermodynamic database software MALT2.

Oxidizing power necessary for oxidative decomposition of a carbon material into carbon dioxide and oxidizing power of various alkali metal compounds are represented by an oxygen potential (log [P (O ₂ )]), and the temperature dependence is shown. 1-3.
1-3, the oxidizing power of carbon and hydrocarbon at each temperature is a curve represented by carbon (C). Necessary for oxidative decomposition of carbon and hydrocarbons into carbon dioxide and water vapor when the oxygen potential (log [P (O ₂ )]) is higher than the curve shown by carbon (C) at each temperature. It shows that it has oxidizing power.

FIG. 1 shows sodium peroxide (Na ₂ O ₂ ), sodium superoxide (NaO ₂ ) as alkali metal compounds having an oxidizing power necessary for oxidative decomposition of carbon and hydrocarbons into carbon dioxide and water vapor. , Sodium nitrate (NaNO ₃ ), sodium molybdate (Na ₂ MoO ₄ ), sodium sulfate (Na ₂ SO ₄ ), and sodium vanadate (NaVO ₃ ). The oxygen potential (log [P (O ₂ )]) indicating the oxidizing power of these alkali metal compounds is the oxygen potential indicating the oxidizing power necessary for oxidative decomposition of carbon and hydrocarbons into carbon dioxide and water vapor ( There is a higher temperature range than log [P (O ₂ )]).
That is, sodium peroxide, sodium superoxide, sodium nitrate, sodium sulfate, sodium vanadate and sodium molybdate have an oxidizing power to oxidatively decompose carbon into carbon dioxide.

FIG. 2 shows lithium peroxide (Li ₂ O ₂ ), sodium peroxide (Na ₂ O) as alkali metal compounds having an oxidizing power necessary for oxidative decomposition of carbon and hydrocarbons into carbon dioxide and water vapor. ₂ ), sodium superoxide (NaO ₂ ), potassium peroxide (K ₂ O ₂ ), potassium superoxide (KO ₂ ). The oxygen potential (log [P (O ₂ )]) indicating the oxidizing power of these alkali metal compounds is the oxygen potential indicating the oxidizing power necessary for oxidative decomposition of carbon and hydrocarbons into carbon dioxide and water vapor ( There is a higher temperature range than log [P (O ₂ )]).
That is, alkali metal peroxides and superoxides have an oxidizing power to oxidatively decompose carbon into carbon dioxide.

FIG. 3 shows lithium sulfate (Li ₂ SO ₄ ) and sodium sulfate (Na ₂ SO ₄ ) as alkali metal compounds having an oxidizing power necessary for oxidative decomposition of carbon and hydrocarbons into carbon dioxide and water vapor. , Potassium sulfate (K ₂ SO ₄ ). The oxygen potential (log [P (O ₂ )]) indicating the oxidizing power of these alkali metal compounds is the oxygen potential indicating the oxidizing power necessary for oxidative decomposition of carbon and hydrocarbons into carbon dioxide and water vapor ( There is a higher temperature range than log [P (O ₂ )]).
That is, the alkali metal sulfate has an oxidizing power for oxidizing and decomposing carbon into carbon dioxide.

(Alkaline alkali metal compounds)
It is preferable that at least one of the alkali metal compounds added to the battery waste material is an alkali metal compound exhibiting alkalinity when dissolved in water (hereinafter sometimes referred to as “alkaline alkali metal compound”). The alkaline alkali metal compound is an alkali metal compound in which the pH of the solution becomes higher than 7 when the alkali metal compound is dissolved in pure water to prepare a solution.
In the present invention, by using an alkaline alkali metal compound, it is possible to increase the processing speed of the carbon material or resin contained in the battery waste material, and to further improve the effect of preventing the generation of corrosive gas. .

Examples of the alkaline alkali metal compound include alkali metal hydroxides, alkali metal carbonates, alkali metal oxides, alkali metal peroxides, and alkali metal superoxides. These compounds are used alone or in combination of two or more.
Examples of suitable alkaline alkali metal compound, LiOH, NaOH, KOH, RbOH , hydroxides such as _{CsOH; Li 2 CO 3, Na} 2 CO 3, K 2 CO 3, RbCO 3, etc. CsCO ₃ of Carbonates; oxides such as Li ₂ O, Na ₂ O, K ₂ O, Rb ₂ O, Cs ₂ O; Li ₂ O ₂ , Na ₂ O ₂ , K ₂ O ₂ , Rb ₂ O ₂ , Cs ₂ O peroxides such as _{2; LiO 2, NaO 2,} KO 2, RbO 2, superoxide such CsO _2; and the like.

<Heating process>
A heating process is a process of heating the mixture of battery waste material and an alkali metal compound.

In the heating step, heating is performed to a temperature at which the combustible substance is decomposed. The highest temperature reached in the heating step is defined as the treatment temperature of the battery waste material.
In order to carry out the heating process stably, it is preferable to hold for a certain period of time at a temperature at which the combustible substance is decomposed. The temperature at this time is taken as the holding temperature, and the time is taken as the holding time.

"Heating process atmosphere"
In the heating process, an optimal atmosphere is set according to the type of combustible substance and alkali metal compound contained in the battery waste material and the combination of the combustible substance and alkali metal compound contained in the battery waste material.
From the viewpoint of promoting oxidative decomposition of the combustible substance, the atmosphere in the heating step is preferably an oxidizing atmosphere containing oxygen, such as air.

"Holding time of heating process"
In the heating process, an optimum holding time is set according to the type of combustible substance and alkali metal compound contained in the battery waste material and the combination of the combustible substance and alkali metal compound contained in the battery waste material. The holding time is usually 1 minute to 48 hours, preferably 10 minutes to 24 hours.

"Processing temperature of heating process"
In the heating step, the treatment temperature may be a temperature at which the combustible substance is decomposed. The temperature at which the combustible substance is decomposed differs depending on the type of combustible substance and alkali metal compound contained in the battery waste material, and the combination of the combustible substance and alkali metal compound contained in the battery waste material. Usually, the higher the processing temperature, the higher the processing speed. However, if the processing temperature is too high, there is a problem that a large amount of energy is consumed for heating and the deterioration of the processing equipment is accelerated.
The minimum of processing temperature is 100 degreeC, More preferably, it is 300 degreeC, More preferably, it is 500 degreeC.
On the other hand, the upper limit of processing temperature is 1500 degreeC, More preferably, it is 1200 degreeC, More preferably, it is 1000 degreeC.

When the mixture of the battery waste material and the alkali metal compound is heated to a temperature equal to or higher than the lowest temperature at which a part of the mixture exhibits a liquid phase, the treatment reaction is accelerated, and the battery waste material and the alkali metal are maintained. Since the contact with the compound is increased, the processing speed can be improved.
When a mixture of battery waste and alkali metal compound is heated, the lowest temperature at which part of the mixture exhibits a liquid phase is the type of combustible and alkali metal compound contained in the battery waste and the combustion contained in the battery waste. In general, the temperature may be lowered to a temperature lower than 100 ° C. than the melting start temperature of the alkali metal compound, depending on the combination of the active substance and the alkali metal compound. Therefore, the holding temperature in the heating step is preferably at least 100 ° C. lower than the melting start temperature of the alkali metal compound, more preferably at least 50 ° C. lower than the melting start temperature.

 By setting the holding temperature of the heating process to be equal to or higher than the melting start temperature of the alkali metal compound, the contact area between the flammable substance contained in the battery waste and the molten alkali metal compound is increased, thereby improving the processing speed. The processing temperature can be lowered.

The treatment temperature varies depending on the type of alkali metal compound added to the battery waste. In particular, the treatment temperature is preferably equal to or higher than the melting start temperature of the alkali metal compound because the treatment speed is improved at the melting start temperature or higher of the alkali metal compound added to the battery waste material. The treatment temperature is more preferably a temperature that is 30 ° C. or more higher than the melting start temperature of the alkali metal compound, and even more preferably a temperature that is 50 ° C. or more higher than the melting start temperature of the alkali metal compound.
Further, the holding temperature is preferably equal to or higher than the melting start temperature of the alkali metal compound.

(Melting start temperature of alkali metal compound)
The melting start temperature (Tmp) of the alkali metal compound is the lowest temperature at which a part of the alkali metal compound exhibits a liquid phase.
In the present invention, the melting start temperature (Tmp) of the alkali metal compound is a value obtained by differential heat measurement (DTA). That is, about 5 mg of a mixture of battery waste material and alkali metal compound was subjected to differential heat measurement (DTA, measurement condition: temperature increase rate: 10 ° C./min), and the temperature at which the DTA signal showed an endothermic peak was the melting start temperature (Tmp) And

 The treatment temperature is preferably higher than the melting point of the alkali metal compound. More preferably, the holding temperature is higher than the melting point of the alkali metal compound. In addition, the melting point of the alkali metal compound may be lower than the melting point of each compound alone by mixing a plurality of types of compounds. When the alkali metal compound is composed of two or more, the eutectic point is the melting point.

 The upper limit of the treatment temperature is preferably 1500 ° C, more preferably 1200 ° C, and still more preferably 1000 ° C.

 EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further more concretely, this invention is not limited to a following example.

 Hereinafter, a method for measuring the reaction start temperature and the processing speed of the combustible substance, a method for measuring the physical property of the combustible substance, and a method for measuring the physical property of the alkali metal compound are shown.

(1) Measurement of flammable substance treatment rate and reaction start temperature by thermogravimetry (TG) The flammable substance treatment rate [sec ^-1 ] at a predetermined temperature is the temperature in thermogravimetry under the following conditions. The amount of combustible substance consumption per unit time [g · sec ⁻¹ ] per unit weight [g] of the combustible substance present in FIG.
The reaction start temperature of the combustible substance is the lowest temperature at which the processing speed of the combustible substance reaches 0.1 [sec ⁻¹ ] in thermogravimetry under the following conditions.
Thermogravimetry (TG) measurement conditions Apparatus: Differential thermothermal gravimetric simultaneous measurement apparatus (TG / DTA6200, manufactured by Seiko Instruments Inc.)
Bread: Platinum Initial sample amount: Approximately 5mg
Atmosphere: Air Temperature rising rate: 10 ° C / min

(2) Measurement of specific surface area of combustible material After 0.5 g of a sample was dried at 150 ° C. for 15 minutes in a nitrogen atmosphere, a BET specific surface area measuring device (Flow Soap II 2300, manufactured by Micromeritics) was used. The BET specific surface area was measured. The specific surface area measured by this method was defined as the specific surface area of the active material.

(3) Measurement of average primary particle diameter by observation with a scanning electron microscope (SEM) A particulate sample is placed on a conductive sheet pasted on a sample stage, and a scanning electron microscope (JSM-5510, manufactured by JEOL Ltd.) is used. Then, an electron beam with an acceleration voltage of 20 kV was irradiated, and three observations between SEMs were performed. The average primary particle size was measured by extracting 50 primary particles arbitrarily from an image (SEM photograph) obtained by SEM observation, measuring each particle size, and calculating the average value.

(4) Measurement of pH of alkali metal compound 3.5 g of the alkali metal compound was added to 70 g of pure water, the mixture was sufficiently stirred with a stirrer, and the pH of the alkali metal compound was measured using a pH meter with a glass electrode.

(5) Measurement of melting start temperature of alkali metal compound by differential heat measurement (DTA) The melting start temperature (Tmp) of the alkali metal compound is determined by partial heat of the alkali metal compound in differential heat measurement (DTA) under the following conditions. The lowest temperature at which an endothermic peak due to melting appears.
Differential thermal measurement (DTA) measurement conditions Device: Differential thermal thermogravimetric simultaneous measurement device (TG / DTA6200, manufactured by Seiko Instruments Inc.)
Bread: Platinum Initial sample amount: Approximately 5mg
Atmosphere: Air Temperature rising rate: 10 ° C / min

“Comparative Example 1”
<Disposal of natural graphite when no alkali metal compound is added>
Natural graphite (BF15SP, manufactured by Chuetsu Graphite Co., Ltd.), which is a carbon material used as a negative electrode active material, was used as the combustible material contained in the battery waste material.
As for the physical properties of natural graphite, the specific surface area measured by the BET specific surface area was 4.9 m ² / g, and the average particle size calculated from the image obtained by SEM observation was 17 μm. Natural graphite passed through a mesh having an opening of 10 mm.
Without adding an alkali metal compound to 0.37 mg of natural graphite, the natural graphite was put in a platinum pan, and the treatment rate of the combustible substance was measured by thermogravimetry (TG). Table 2 shows the reaction start temperature and the treatment rate at each temperature.

"Example 1"
<Disposal treatment when Li ₂ CO ₃ and Na ₂ SO ₄ are added to natural graphite>
As an alkali metal compound, 1.45 g of Li ₂ CO ₃ and 2.87 g of Na ₂ SO ₄ were added and mixed with a mortar.
The melting start temperature of the alkali metal compound composed of Li ₂ CO ₃ and Na ₂ SO ₄ was 553 ° C.
Further, pH of alk metal compound consisting of _Li 2 CO ₃ and _Na 2 SO ₄ is 11, was alkaline alkali metal.
Na ₂ SO ₄ is an oxidizing alkali metal compound.
0.05 g of an alkali metal compound composed of Li ₂ CO ₃ and Na ₂ SO ₄ was added to 0.50 g of natural graphite (BF15SP, manufactured by Chuetsu Graphite Co., Ltd.), which is a combustible substance.
4.4 mg of the mixture of the flammable substance and the alkali metal compound was put in a platinum pan, and the treatment rate of the flammable substance was measured by thermogravimetry (TG). The combustible substance in the mixture was 4.0 mg.
The processing rate of the combustible material was measured by thermogravimetry (TG). Table 2 shows the reaction start temperature and the treatment rate at each temperature.

The reaction start temperature of Example 1 was lower than that of Comparative Example 1. In addition, the processing speed at each temperature was higher in Example 1 than in Comparative Example 1.
That is, by adding an alkali metal compound composed of Li ₂ CO ₃ and Na ₂ SO ₄ to natural graphite (BF15SP, manufactured by Chuetsu Graphite Co., Ltd.), which is a combustible substance, the reaction start temperature is lowered and the processing speed is improved. did.

“Comparative Example 2”
<Disposal of graphite conductive material without alkali metal compound added>
As a combustible substance contained in the battery waste material, graphite powder (SNO-3, manufactured by SEC Carbon Co.), which is a carbon material used as a positive electrode graphite conductive material, was used.
As for the physical properties of the graphite powder, the specific surface area measured by BET specific surface area was 16 m ² / g, and the average particle diameter calculated from the image obtained by SEM observation was 3 μm. The graphite conductive material passed through a mesh having an opening of 10 mm.
The graphite powder was put into a platinum pan without adding an alkali metal compound to 3.4 mg of graphite powder, and the treatment rate of the combustible substance was measured by thermogravimetry (TG). Table 4 shows the reaction start temperature and the treatment rate at each temperature.

"Example 2"
<Disposal treatment when Li ₂ CO ₃ and Na ₂ SO ₄ are added to the graphite conductive material>
As an alkali metal compound, 1.45 g of Li ₂ CO ₃ and 2.87 g of Na ₂ SO ₄ were added and mixed with a mortar.
The melting start temperature of the alkali metal compound composed of Li ₂ CO ₃ and Na ₂ SO ₄ was 533 ° C.
Further, pH of alk metal compound consisting of _Li 2 CO ₃ and _Na 2 SO ₄ is 11, was alkaline alkali metal.
Na ₂ SO ₄ is an oxidizing alkali metal compound.
0.43 g of an alkali metal compound composed of Li ₂ CO ₃ and Na ₂ SO ₄ was added to 0.50 g of graphite powder (SNO-3, manufactured by SEC Carbon Co.), which is a combustible substance.
4.4 mg of the mixture of the flammable substance and the alkali metal compound was put in a platinum pan, and the treatment rate of the flammable substance was measured by thermogravimetry (TG). In addition, the combustible substance in the mixture was 2.4 mg.
The processing rate of the combustible material was measured by thermogravimetry (TG). Table 4 shows the reaction start temperature and the treatment rate at each temperature.

The reaction start temperature of Example 2 was lower than that of Comparative Example 2. In addition, the processing speed at each temperature was higher in Example 2 than in Comparative Example 2.
That is, by adding an alkali metal compound composed of Li ₂ CO ₃ and Na ₂ SO ₄ to graphite powder (SNO-3, manufactured by SEC Carbon Co.), which is a combustible substance, the reaction start temperature is lowered and the processing speed is reduced. Improved.

 According to the battery waste material disposal method of the present invention, it is possible to treat combustible substances contained in the battery waste material at a lower temperature and to obtain an effect of obtaining a high treatment speed. Therefore, the energy consumed for the disposal of the battery waste material can be greatly reduced, which is industrially promising.

Claims (11)

 A battery waste material comprising: an addition step of adding an alkali metal compound to a battery waste material having a mesh shape having a mesh opening of 10 mm; and a heating step of heating a mixture of the battery waste material and the alkali metal compound. Disposal method.  The disposal method of the battery waste material of Claim 1 including the crushing process which makes the said battery waste material the shape which passes a mesh with an opening of 10 mm.  The disposal method of the battery waste material according to claim 1 or 2, wherein the battery waste material contains a carbon material.  The disposal method of the battery waste material of Claim 3 containing graphite as said carbon material. The disposal method of the battery waste material according to claim 3 or 4, wherein the carbon material has a specific surface area of 0.1 to ²⁰ m ² / g.  The battery waste disposal method according to any one of claims 1 to 5, wherein a holding temperature in the heating step is equal to or higher than a temperature lower by 100 ° C than a melting start temperature of the alkali metal compound.  The battery waste material disposal method according to any one of claims 1 to 5, wherein a holding temperature in the heating step is equal to or higher than a melting temperature of the alkali metal compound.  The battery waste material according to any one of claims 1 to 7, wherein the alkali metal compound is an oxidizing alkali metal compound having an oxidizing power to oxidatively decompose the carbon material at a holding temperature in the heating step. Disposal method.  The oxidizable alkali metal compound is made of an alkali metal peroxide, an alkali metal superoxide, an alkali metal nitrate, an alkali metal hydrochloride, an alkali metal vanadate and an alkali metal molybdate. The method for disposing of waste battery materials according to claim 8, which is at least one selected from the above.  The method for disposing of battery waste materials according to any one of claims 1 to 9, wherein the alkali metal compound is alkaline when dissolved in water.  The alkaline alkali metal compound is at least one selected from the group consisting of alkali metal hydroxides, alkali metal carbonates, alkali metal hydrogen carbonates, alkali metal oxides and alkali metal superoxides. The battery waste material disposal method according to claim 10.

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