JP3532640B2 - Method for recovering positive electrode material from nickel-hydrogen secondary battery and method for recovering raw material for recovering effective metal from negative electrode - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for recovering a positive electrode material from a nickel-hydrogen secondary battery and a method for recovering a raw material for recovering a negative electrode effective metal which are effective for recycling the nickel-hydrogen secondary battery.

[0002]

2. Description of the Related Art In recent years, the demand for secondary batteries has rapidly increased due to the portable electronic products. Further, nickel-metal hydride secondary batteries have been improved as a pollution-free battery for electric vehicles, and attention is focused on future demand expansion. As described above, the nickel-hydrogen secondary battery is superior in characteristics to the conventional nickel-cadmium battery and has less environmental problems. Therefore, it is expected that the demand thereof will be expanded in the future.

[0003] With such an increase in demand, there has been proposed an attempt to recover and reuse an effective metal from a used nickel hydrogen secondary battery. For example, a method for recovering a negative electrode material from a negative electrode constituent substance and a positive electrode constituent substance of a used nickel hydrogen secondary battery (PCT published patent publication WO94 / 23).
073) is known. However, a method for recovering the positive electrode constituent substance as a positive electrode material has not yet been established. This is because when using conventional chemical treatment methods, solvent extraction separation methods, evaporation separation methods, etc., the cost is higher than when using new raw materials, and when recovering only the positive electrode material, This is because zinc contained in the positive electrode constituent substance may be mixed in the negative electrode material, and the performance of the recovered negative electrode material may be deteriorated. Therefore, it has a purity that can be used for a negative electrode material recovery method such as a positive electrode material recovery method for a nickel-hydrogen secondary battery whose environment is increasing in demand and a method for recovering the negative electrode material (PCT published patent publication WO94 / 23073). It is desired to develop an excellent method for recovering a raw material for recovering a negative electrode effective metal.

[0004]

An object of the present invention is to provide a, yet low cost it is possible to efficiently recovered positive electrode material of nickel-hydrogen rechargeable batteries, the effective nickel-hydrogen secondary battery also in recycling surface Another object of the present invention is to provide a positive electrode material recovery method.

Another object of the present invention, the negative electrode material having high efficiency pure low-cost, yet nickel-hydrogen secondary batteries
And to provide a recovery method of the negative electrode effective metal recovery raw material of nickel-hydrogen rechargeable battery that allows recovered.

[0006]

According to the present invention, a nickel-hydrogen secondary battery is crushed to obtain a crushed product, and an alkali content, an organic substance and an iron content are separated from the crushed product to obtain at least an alkali content and an organic content. A step (I) of obtaining a separated component in which a substance and iron are separated, and adding caustic to the separated component,
After separating the zinc component in the positive electrode material as an alkali zinc salt,
Nickel content and the cobalt content in the positive electrode material was dissolved as an ammonia complex salt, a positive electrode material recovery process from a nickel-hydrogen rechargeable battery comprising a step of separation (II). Also
According to the present invention, the nickel-hydrogen secondary battery is crushed and crushed.
To obtain an alkaline substance, organic substances and iron from the crushed product.
Separate at least alkali, organics and iron
Step (I) of obtaining a separated separated component, and the separated component
After ammonia treatment, nickel content in the positive electrode material, cobalt
Toxin and zinc are dissolved as ammonia complex salt and separated
From the nickel-hydrogen secondary battery including the step ( III)
A polar material recovery method is provided.

Further in accordance with the present invention, the above step (I),
After performing the step ( II ) and the step (II) ,
Dissolve nickel and cobalt as ammonia complex salt
And recovery method of the negative electrode effective metal recovery raw material of nickel-hydrogen rechargeable batteries, and recovering the remaining precipitation lees of when the separation is provided. Still further according to the invention, said
After performing the step (I) and the step ( III) , the step
Recovering the residual precipitate when separated in (III)
Effective metal for negative electrode from nickel-hydrogen secondary battery characterized by
A method of recovering a raw material for recovery is provided.

The present invention will be described in more detail below.
In the recovery method of the present invention, first, a step (I) is performed in which a nickel-hydrogen secondary battery is crushed to obtain a crushed product, and a separated component obtained by separating an alkali content, an organic substance and an iron content from the crushed product is obtained.

The nickel-hydrogen secondary battery can be crushed, for example, by using a biaxial shearing crusher or the like, preferably into small pieces of 5 mm or less.

The alkali content such as potassium hydroxide can be separated from the crushed material by a method of washing the crushed material.

To separate the organic substance from the crushed material,
For example, it can be carried out by treating the crushed material from which the alkali content has been separated by a wet specific gravity fractionation method using a commercially available wet specific gravity sorter or the like. Organic materials such as plastics and separators can be separated by the wet specific gravity fractionation method or the like.

In order to separate the iron content from the crushed material, for example, the crushed material in which the alkali content and the organic substance are separated is
It can be carried out by processing by a fractionation method such as a magnetic fractionation method, a specific gravity fractionation method or a sieve fractionation method. As the magnetic separation method, for example, an electromagnetic magnet separator or the like, as the specific gravity separation method, for example, thickener, wet cyclone, or the like, and as the sieve separation method, for example, a wet vibration sieving machine or the like can be used. It can also be performed in combination.

In the step (I), an alkali content,
By separating organic substances and iron, nickel hydrogen 2
From the secondary battery, nickel hydroxide in the positive electrode material, cobalt hydroxide, zinc hydroxide and / or zinc oxide, and at least an alkali component such as nickel rare earth metal alloy powder which is a main constituent in the negative electrode material, organic It is possible to recover a separated component obtained by separating the substance and the iron content.

Next, in the recovery method of the present invention, caustic alkali is added to the separation component to separate the zinc component in the positive electrode material as an alkali zinc salt of zinc, and the nickel component and the cobalt component in the positive electrode material as an ammonia complex salt. dissolved by performing the step of separation (II), or the process by ammoniated the resulting separated components (I), dissolved nickel content in the positive electrode material, a cobalt component and a zinc component, as an ammonia complex salt and by separation to step (III) the rows Ukoto can be recovered cathode material of interest.

In the step (II), first, caustic alkali is added to the separated component to remove the zinc content in the positive electrode material,
It is dissolved and separated as an alkali zinc salt. Examples of the caustic alkali include caustic soda and caustic potash. The amount of caustic alkali added is not particularly limited as long as it is a concentration capable of converting zinc content into a soluble salt as an zinc salt of zinc acid, but the amount of water in the separated component and the caustic alkali to be added (including water content). However, the concentration is preferably 10% by weight or more, particularly preferably 10 to 85% by weight. The reaction at this time can be carried out preferably by a method in which the caustic alkali concentration is maintained at the above-mentioned concentration and the reaction is stirred at room temperature to 200 ° C. for 1 to 10 hours. The reaction formula at this time is as follows: Zn (OH) ₂ + OH ~ = [Zn (OH) ₃ ] ~
Becomes This reaction can be carried out using a device such as a tank equipped with a stirrer, a wet ball mill, a kneader blender, and an autoclave.

Separation of the zinc component as an alkali zinc salt from the separation component can be carried out by a usual filtration process using an alkali-resistant filter. In this case, when the neutralization treatment after filtration is taken into consideration, the solution before or after filtration is diluted with water or the like to reduce the caustic alkali concentration after the reaction, preferably to an alkali concentration of about 5% by weight or less. Is desirable. By lowering the caustic alkali concentration in this way, the viscosity of the solution can be lowered and filtration can be facilitated. The filtered solution is
After neutralization with an acid such as hydrochloric acid, sulfuric acid or nitric acid, sodium carbonate, sodium bicarbonate or the like is added to precipitate and recover the zinc component as basic zinc carbonate.

[0017] In the next step (II), after separation of zinc alkali salts, nickel content and the cobalt content in the positive electrode material was dissolved as an ammonia complex salt, for separation.

In the step (II), in order to convert the nickel content and the cobalt content in the positive electrode material into an ammonia complex salt, a method of adding concentrated ammonia water or the like to the separated component after the separation of the zinc acid alkali salt and reacting it, It can be carried out by a method of filling ammonia gas and reacting under pressure. The concentration of the concentrated aqueous ammonia or the ammonia gas is particularly limited as long as the nickel content (nickel hydroxide) and the cobalt content (cobalt hydroxide) contained therein are concentrations that allow the reaction to become soluble salts as ammonia complex salts. However, it is preferable to add 7 mol ratio or more in terms of NH _{3 with} respect to the total mol of nickel and cobalt contained. At this time, the reaction can be carried out by a method of stirring reaction at room temperature to 200 ° C. for 1 to 10 hours when adding concentrated ammonia water. This reaction can be carried out using an apparatus such as a tank equipped with a stirrer and a wet ball mill. On the other hand, when the reaction is carried out in a pressurized state with ammonia gas, the reaction can be carried out at a pressure of 1 to 10 atmospheres and a temperature of room temperature to 200 ° C. for 1 to 10 hours. This reaction can be carried out using a device such as an autoclave. These reactions can be represented by the following reaction formula 1.

[0019]

[Chemical 1]

Further, in order to accelerate the above reaction, ammonia salts such as ammonium chloride and ammonium nitrate can be further added to the reaction system. The added amount of ammonia salts is the total mol of nickel and cobalt contained.
However, it is preferable to add it in a ratio of 0 to 10 mol.

[0021] Such nickel content and ammonia complexes of cobalt values obtained in is dissolved as soluble salts, to separation of the ammonia complex salt, a method to more filtration to normal pressure filtration machine or the like, etc. Can be separated by. The separated solution may be neutralized with an acid such as hydrochloric acid, sulfuric acid or nitric acid, and then sodium carbonate, sodium bicarbonate or the like may be added thereto to precipitate and recover it as a nickel-cobalt mixed basic carbonate. At this time, in order to facilitate the filtration, a method of diluting the ammonia complex salt-containing solution with water or the like before the filtration can be used as in the case of separating the zinc content described above.

[0022] In the recovery process of the negative electrode effective metal recovery material of the present invention, the zinc content of the positive electrode material as described above, be carried out by recovering the residual presence precipitate after separation of the nickel content and the cobalt content it can. The obtained raw material for recovering the negative electrode effective metal is washed with water and then calcined to obtain an oxide, and the oxide is treated by a molten salt electrolysis method in a molten salt bath for electrolysis. For example, a known method (PCT published patent publication WO94 / 2307
By utilizing 3) or the like, the negative electrode effective metal can be recovered from the nickel-hydrogen secondary battery.

On the other hand, in the step (III) of the present invention, the separated component obtained in the step (I) is treated with ammonia,
Nickel content in the positive electrode material, a cobalt component and a zinc component, dissolved as the ammonia complex salt, for separation.

The treatment with ammonia in step (III) can be carried out in the same manner as in the formation of the ammonia complex salt in step (II). That is, in order to convert the nickel content, the cobalt content and the zinc content in the positive electrode material into an ammonia complex salt, a method of adding concentrated ammonia water or the like to the separated components obtained in the step (I) and reacting them, ammonia gas It can be carried out by a method of filling and reacting under pressure. Regarding the concentration of the concentrated ammonia water or ammonia gas, the nickel content (nickel hydroxide), cobalt content (cobalt hydroxide) and zinc content (zinc hydroxide and / or zinc oxide) contained therein become a soluble salt as an ammonia complex salt. The concentration is not particularly limited as long as it is a concentration at which the reaction proceeds, but preferably the total m of nickel, cobalt and zinc contained
It is desirable to add at least 7 mol ratio in terms of NH _{3 with} respect to ol. At this time, the reaction can be carried out by a method of stirring reaction at room temperature to 200 ° C. for 1 to 10 hours when adding concentrated ammonia water. On the other hand, when the reaction is carried out in a pressurized state with ammonia gas, the pressure is 1 to 1
The reaction can be carried out at a temperature of room temperature to 200 ° C. at 0 atmosphere for 1 to 10 hours. These reactions can be represented by the following reaction formula 2.

[0025]

[Chemical 2]

In order to accelerate the above reaction, ammonia salts such as ammonium chloride and ammonium nitrate may be further added to the reaction system. The ammonia salt is preferably added in a ratio of 0 to 10 mol based on the total mol of the nickel component, the cobalt component and the zinc component contained.

In the step (III), before the nickel content, the cobalt content and the zinc content in the positive electrode material are dissolved as an ammonia complex salt, a treatment for converting zinc into a form that promotes complexation can be performed. . In the treatment, ammonium chloride is added in an amount of 2 mol times or more, preferably 5 to 20 mol times the amount of zinc present in the positive electrode material.
Water in which the zinc content (zinc oxide) contained therein is easily promoted to be complexed by adding and mixing in the form of an aqueous solution or a solid powder having a concentration of not less than wt% and reacting at a temperature of 50 to 150 ° C. for 1 to 5 hours. It can be carried out by a method of changing it into a form such as zinc oxide or an oxychloride complex salt.

The ammonia complex salt thus obtained is dissolved as a soluble salt, and in order to separate the ammonia complex salt , it is separated by a conventional method such as filtration with a pressure filter. be able to. The separated solution may be neutralized with an acid such as hydrochloric acid, sulfuric acid or nitric acid, and then sodium carbonate, sodium bicarbonate or the like may be added thereto to precipitate and collect it as a mixed basic carbonate. At this time, in order to facilitate the filtration, a method of diluting the ammonia complex salt-containing solution with water or the like before the filtration can be used.

[0029] In the recovery process of the negative electrode effective metal recovery material of the present invention, the zinc content of the positive electrode material as described above, be carried out by recovering the residual presence precipitate after separation of the nickel content and the cobalt content it can. The obtained raw material for recovering the negative electrode effective metal is washed with water to obtain an oxide, and the oxide is treated by a molten salt electrolysis method in a molten salt bath for electrolysis. For example, a known method (PCT published patent publication WO94 / 2307).
By utilizing 3) or the like, the negative electrode effective metal can be recovered from the nickel-hydrogen secondary battery.

[0030]

The positive electrode material recovery method of the present invention, the negative electrode material
Since it can separate the positive electrode material and the positive electrode material, it is harmful to the negative electrode alloy.
A zinc can be prevented from being mixed in the negative electrode material. Further, since the positive electrode material can be efficiently recovered from the nickel-hydrogen secondary battery, the effective electrode material can be recycled, and moreover, it can be recovered inexpensively and in a large amount in comparison with ordinary separation and purification. Further, in the step (III), by changing zinc to a form that promotes complexation, it is possible to more reliably recover zinc as a positive electrode material.

In the method for recovering the raw material for recovering the effective metal of the negative electrode of the present invention, the residual material in the recovery method for the positive electrode material can be recovered, so that the recovered raw material does not contain harmful zinc in the negative electrode material. As a raw material, it can be used to recover a high-purity negative electrode effective metal.

[0032]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto.

[0033]

Example 1 A used nickel hydrogen secondary battery (575 g of a positive electrode material necessary for recovery, 820 g of a negative electrode material) was crushed into small pieces of 5 mm or less by a biaxial shearing crusher, and then charged into a container with a stirrer. Then, the mixture was stirred while flowing water, and the alkali content was removed by overflow. Then, after removing organic substances with a wet specific gravity sorter, the residual metal is removed with a wet electromagnetic vibrating screen to remove iron, filtered, and then nickel hydroxide, cobalt hydroxide, zinc hydroxide of the positive electrode and nickel rare earth of the negative electrode A mixture of alloy powders was obtained as the recovered product of step (I). The filter cake was placed in a stainless steel ball mill, a small amount of water and 100 g of caustic soda were added, and the mixture was stirred for 10 hours. The temperature rose to 60 ° C due to self-heating.

Next, the contents were poured out with water and filtered. The resulting filtrate was neutralized with hydrochloric acid to adjust the pH to 6.3 and then 40
250 ml of 0 g / liter sodium carbonate solution was added to precipitate basic zinc carbonate, which was filtered off. The recovered basic zinc carbonate was obtained as ZnO in an amount of 25.9 g.

On the other hand, since the residual solid matter is nickel hydroxide, cobalt hydroxide and nickel rare earth metal alloy, it is washed well with water to remove the residual alkali, and then 2000 ml of concentrated 15N ammonia water is added to a container with a stirrer. Put, 60 ℃
And reacted with stirring for 5 hours. The reaction product was taken out and filtered with a pressure filter. The filtrate was neutralized with hydrochloric acid, sodium carbonate solution was added at pH 6.3 to precipitate nickel-cobalt mixed basic carbonate, which was filtered and then dissolved in nitric acid to prepare a stock solution for producing hydroxide for positive electrode. The recovered nickel is 320 g as pure Ni, and cobalt is 17.6 g as pure Co.
Met.

A raw material for recovering the negative electrode effective metal containing the remaining nickel rare earth alloy of the negative electrode was recovered. 80 this raw material
It was baked in an electric furnace at 0 ° C. for 2 hours to change to an oxide. The obtained oxide was 1033 g. Its composition is NiO:
55.2% by weight, oxide rare earth metal: 26.9% by weight,
Co ₂ O _3: 7.8 wt%, Al ₂ O _3: 2.8 wt%, M
nO ₂ : It was 5.3% by weight.

[0037]

[Example 2] The same treatment as in Example 1 was carried out to recover a used product (a positive electrode material 574) from a used nickel-hydrogen secondary battery in step (I).
g, containing 820 g of the negative electrode material). This filter cake is placed in an autoclave equipped with a stirrer, and 150 ml of ammonium chloride is added.
g, 2300 ml of 15N ammonia water was added to 100
The mixture was reacted with stirring at 5 ° C for 5 hours. After completion of the reaction, the mixture was filtered with a pressure filter to obtain a nickel-cobalt-zinc ammonia complex salt solution and a negative electrode nickel rare earth metal alloy. The ammonia complex salt solution was neutralized with hydrochloric acid, and then 550 ml of a 400 g / liter sodium carbonate solution having a pH of 6.3 was added to precipitate a nickel-cobalt-zinc mixed basic carbonate. Then, the precipitate was filtered off and dissolved in nitric acid to obtain a raw material for molten salt electrolysis for producing a positive electrode hydroxide. The recovered nickel is 34% pure Ni.
3g, cobalt is 21.9g as pure Co, and zinc is Z
The amount of pure n was 22.4 g.

On the other hand, the raw material for recovering the negative electrode effective metal containing the remaining nickel rare earth alloy of the negative electrode was recovered. 80 this raw material
It was calcined at 0 ° C. for 2 hours to change to an oxide. The obtained oxide was 985 g, and the composition thereof was NiO: 51.5% by weight, rare earth metal oxide: 28.3% by weight, Co ₂ O ₃ : 7.
6% by weight, Al ₂ O ₃ : 3.0% by weight, MnO ₂ : 5.6
% By weight.

[0039]

Example 3 A rare earth metal fluoride was prepared by mixing 1985 g of the rare earth metal oxide for the misch metal raw material with 985 g of the oxide from the raw material for recovering the negative electrode effective metal obtained in Example 2.
(RF ₃ ) 65% by weight, LiF 20% by weight and BaF ₂ 15
An alloy was obtained by performing electrolytic treatment at 950 ° C. while pouring it into a molten salt bath for electrolysis of wt%. The weight of the obtained alloy was 1410 g, and the composition of the alloy was 69.9 of rare earth metal.
%, Nickel 23.5%, cobalt 3.1%, aluminum 0.9%, and manganese 2.5%. By adjusting the composition of this alloy and melting it in an argon atmosphere high frequency furnace, it was possible to regenerate it as a negative electrode material for a nickel-hydrogen secondary battery.

Continuation of the front page (56) Reference JP-A-48-50931 (JP, A) JP-A-51-86002 (JP, A) JP-A-52-46303 (JP, A) JP-A-52-108321 (JP , A) JP 53-53516 (JP, A) JP 1-126221 (JP, A) JP 5-263156 (JP, A) JP 6-207227 (JP, A) International Publication 94 / 023073 (WO, A1) (58) Fields investigated (Int.Cl. ⁷ , DB name) C22B 1/00-61/00 H01M 10/54

Claims (6)

(57) [Claims] 1. A crushed nickel-hydrogen secondary battery is obtained to obtain a crushed product, and an alkali component, an organic substance and an iron component are separated from the crushed substance to obtain a separated component in which at least an alkali component, an organic substance and an iron component are separated. and step (I), adding the separated components in the caustic, after separation of the zinc content in the positive electrode material as zinc alkaline salt, to dissolve the nickel content and the cobalt content in the positive electrode material as an ammonia complex salt, to separation A method for recovering a positive electrode material from a nickel-hydrogen secondary battery, including the step (II). 2. A crushed product obtained by crushing a nickel-hydrogen secondary battery.
From the crushed material to separate alkali content, organic matter and iron content.
Away at least alkali, organics and iron
The step (I) of obtaining separated separated components, and
Nickel and cobalt in the positive electrode material after ammonia treatment
And zinc components are dissolved as ammonia complex salts and separated.
Positive electrode from nickel-hydrogen secondary battery including the step ( III)
Material recovery method. 3. The separated component in the step (III)
Treated with ammonia to remove the nickel content and
Lute and zinc are dissolved as ammonia complex salt
The positive electrode material recovery method from a nickel-hydrogen secondary battery according to claim 2 , wherein an ammonia salt is added at this time . 4. A crushed product is obtained by crushing a nickel-hydrogen secondary battery, and an alkali component, an organic substance and an iron component are separated from the crushed substance to obtain a separated component in which at least an alkali component, an organic substance and an iron component are separated. and step (I), adding the separated components in the caustic, after separation of the zinc content in the positive electrode material as zinc alkaline salt, to dissolve the nickel content and the cobalt content in the positive electrode material as an ammonia complex salt, to separation Process
(II) and after, nickel content in the step (II)
And cobalt content are dissolved as ammonia complex salt and separated.
Recovery process of the negative electrode effective metal recovery raw material of nickel-hydrogen rechargeable batteries, and recovering the remaining precipitation lees of time was. 5. A crushed material obtained by crushing a nickel hydrogen secondary battery.
From the crushed material to separate alkali content, organic matter and iron content.
Away at least alkali, organics and iron
The step (I) of obtaining separated separated components, and
Nickel and cobalt in the positive electrode material after ammonia treatment
And zinc components are dissolved as ammonia complex salts and separated.
That step (III) and after, minutes in the step (III)
A nickel-based product characterized by recovering the remaining precipitate when separated.
Recovery of raw materials for negative electrode effective metal recovery from hydrogen secondary batteries
Law. 6. The separated component in the step (III)
Treated with ammonia to remove the nickel content and
Lute and zinc are dissolved as ammonia complex salt
At that time, the claim characterized by adding ammonia salts
Item 5. The negative electrode effective metal element from the nickel-hydrogen secondary battery according to Item 5.
Recovery method for expropriated raw materials.