JP2021091940A - Valuable metal recovery method from waste battery - Google Patents

Abstract

To provide a method for efficiently and inexpensively recovering valuable metal contained in a waste battery.SOLUTION: Treatment includes a roasting step S1 of roasting a waste battery to obtain a roasted mater; a crushing step S2 of crushing the roasted matter to obtain a crushed matter; a sieving step S4 of sieving the crushed matter into a sieved matter and a matter on the sieve; and a reduction melting step S6 of reduction melting the sieved matter to obtain a reduction matter and a slag. A furnace used in the reduction melting step S6 is an induction furnace IF, and adds a massive carbonaceous reducer to the induction furnace IF. The carbonaceous reducer is charged into the furnace, and thereby the carbonaceous reducer is heated by induction heating and in-furnace temperature is raised, and the waste battery can be melted while reducing it. Thus, metal containing valuable metal can be efficiently obtained.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method for recovering valuable metals from waste batteries. More specifically, the present invention relates to a recovery method for recovering valuable metals from a waste battery such as a lithium ion battery.

In recent years, lithium-ion batteries have become widespread as lightweight, high-output secondary batteries. As a lithium ion battery, a negative electrode material in which a negative electrode active material such as graphite is fixed to a negative electrode current collector made of copper foil in an outer can made of metal such as aluminum or iron, and nickel in a positive electrode current collector made of aluminum foil. A positive electrode material to which a positive electrode active material such as lithium acid or lithium cobaltate is fixed, a separator made of a porous resin film such as polypropylene, and an electrolytic solution containing an electrolyte such as _{lithium hexafluorophosphate (LiPF 6) are sealed.} It has been known.

One of the main uses of lithium-ion batteries is hybrid vehicles and electric vehicles, but it is expected that a large amount of lithium-ion batteries installed in the future will be discarded along with the life cycle of the vehicle. Many proposals have been made to reuse such used batteries and defective products generated during manufacturing as resources. One of them is a dry process in which the entire amount of waste batteries is melted in a high-temperature furnace.

Waste batteries contain impurities such as carbon, aluminum, fluorine, and phosphorus in addition to valuable metals such as nickel, cobalt, and copper. It is necessary to remove these impurities in order to recover valuable metals from waste batteries. In particular, fluorine and phosphorus are contained as persistent organic substances, and it is necessary to avoid inadvertently releasing them into the atmosphere or the environment such as rivers as gas or wastewater.

Furthermore, among various batteries, lithium-ion batteries are characterized by high capacity and high voltage, so in order to dispose of them, detoxification treatment that discharges the charge remaining in the waste lithium-ion batteries to eliminate them and disassemble them safely is essential. I can't.
As a specific treatment method, for example, a waste battery is roasted to make it harmless, then crushed or crushed, and then separated by processing such as sieving or magnetic separation, and valuable metals are recovered from the separated material. There is a way to do it.
The valuable metal recovered by this method can be subjected to a known dry treatment or wet treatment to further separate impurities to obtain a highly purified valuable metal. Then, the valuable metal can be used again as a raw material for a lithium ion battery, for example.

As a method for recovering cobalt from a waste battery by using a dry treatment, Patent Document 1 proposes a treatment in which the waste battery is put into a melting furnace and oxidized by oxygen.
Further, Patent Document 2 proposes a process of removing phosphorus by melting a waste battery, separating slag and recovering valuable resources, and then adding a lime-based flux in the dephosphorization step to melt the battery. There is.

A furnace is required to melt and reduce the waste battery by using the dry treatment as described above.
Reactors include plasma furnaces, arc furnaces, and induction furnaces. However, plasma furnaces and arc furnaces have a problem that the equipment cost is high and it is difficult to finely adjust the reduction degree.
On the other hand, the induction furnace has a feature that the degree of reduction can be adjusted relatively easily, but in order to heat with an induced current, it is necessary to interpose a metal or graphite (carbon) that easily conducts electricity. For this reason, it is necessary to add extra cost to put the metal for heating in the waste battery, or to heat from the crucible using a graphite crucible. Moreover, especially when the latter graphite crucible is used, graphite itself can also be a reducing agent, so that the reduction of the waste battery to be melted progresses excessively, and the graphite crucible is easily oxidized and damaged, resulting in the cost of the crucible. There are problems such as increased labor for replacement and impairing production efficiency and stability.

As described above, when reducing and melting a waste lithium ion battery, many problems remain in terms of cost and efficiency.

Japanese Unexamined Patent Publication No. 2013-91826 Japanese Patent Application Laid-Open No. 2013-506048

In view of the above circumstances, an object of the present invention is to provide a method for efficiently and inexpensively recovering valuable metals contained in a waste battery.

The valuable metal recovery method from the waste battery of the first invention includes a roasting step of roasting the waste battery to obtain a roasted product, a crushing step of crushing the roasted product to obtain a crushed product, and a sieve of the crushed product. A method of recovering valuable metal from a waste battery by subjecting it to a process having a sieving step of separating the sieving product and a sieving product and a reduction melting step of reducing and melting the sieving product to obtain a reduced product and slag. In the above, the furnace used in the reduction melting step is an induction furnace, and is characterized in that a massive carbonaceous reducing agent is added to the induction furnace.
In the method for recovering valuable metals from waste batteries of the second invention, in the first invention, the amount of the bulky carbonaceous reducing agent to be added is 100% by mass, which is the total amount of the reducing agent and the slag discharged from the induction furnace. It is characterized in that it is controlled so as to be in the range of 0.1% by mass or more and 18% by mass or less.
Valuable metal recovery process from the waste battery of the third aspect of the present invention, in the first or second invention, wherein the carbonaceous reducing agent massive added is the size of 1cm ³ ~1000cm ^3.
The method for recovering valuable metals from a waste battery according to the fourth invention is characterized in that, in the first, second or third invention, the composition of the lumpy carbonaceous reducing agent to be added is 65% by mass or more of carbon grade.
The method for recovering valuable metal from a waste battery of the fifth invention is characterized in that, in the first invention, a magnetic separation step of removing iron as a magnetic deposit is performed before or after the sieving step.
The method for recovering valuable metals from a waste battery according to the sixth aspect of the present invention is characterized in that, in the first or fifth invention, the oxidative roasting step of oxidatively roasting the sieve material is performed before the reduction melting step.
In the method for recovering valuable metals from waste batteries of the seventh invention, in the first, second, third, fourth, fifth or sixth invention, the valuable metals to be recovered are selected from at least cobalt, nickel, and copper. It is characterized by having one or more kinds.

According to the first invention, the waste battery is made easy to be crushed by roasting in the roasting step, and when the whole amount of the waste battery is finely crushed in the crushing process to obtain a crushed product, a sieved product is obtained in the sieving process. By separating the sieving product into the sieving product, the sieving product is ready to be subjected to the reduction melting step.
Then, in the reduction melting step, the massive carbonaceous reducing agent is put into the furnace and the massive carbonaceous reducing agent is heated by induction heating to raise the temperature inside the furnace. When the massive carbonaceous reducing agent generates heat due to induction heating, the reduction reaction of the sieve material in the furnace proceeds and metal is produced. The metal generated at the same time receives the induction heating of the induction furnace and generates heat, and the temperature inside the furnace rises. Therefore, the slag that cannot be induced and heated can be melted by this heat generation. In this way, when the metal is produced and the temperature inside the furnace is raised at the same time and the waste battery is melted while being reduced, a metal containing a valuable metal can be obtained efficiently and inexpensively.
According to the second invention, the amount of the bulky carbonaceous reducing agent is in the range of 0.1% by mass or more and 18% by mass or less, assuming that the total amount of the reducing agent and the slag discharged from the induction furnace is 100% by mass. By controlling the concentration so as to be, the frequency of contact between the molten waste battery and the carbonaceous reducing agent is increased, and the reduction reaction proceeds efficiently.
According to the third invention, the carbonaceous reductant massive to be added is an individual volume When it is 1 cm ³ ～1000Cm ^3, does not become too large or too small size increases the opportunities for contact heating is performed sufficiently Therefore, the amount of heat generated per surface area from the carbonaceous reducing agent also increases.
According to the fourth invention, since the carbon grade of the massive carbonaceous reducing agent is 65% by mass or more, the reduction efficiency is high and the contamination of impurities is reduced.
According to the fifth invention, when the magnetic separation is performed, the iron content can be removed, so that the melting point and viscosity of the slag can be easily designed, and the processing cost in the wet process of the subsequent process can be reduced.
According to the sixth invention, since the quality of the waste battery can be made uniform by oxidizing the component that can be a reducing agent in the waste battery by oxidative roasting, the degree of reduction can be easily controlled.
According to the seventh invention, cobalt, nickel, and copper can be reused in various industries and can be reused as a raw material for a lithium ion battery.

It is a process drawing which shows an example of the valuable metal recovery method which concerns on this invention. It is a detailed explanatory drawing of the reduction melting step S6.

Next, an embodiment of the present invention will be described with reference to the drawings.
The waste batteries to which the valuable metal recovery method of the present invention can be applied are not limited to lithium ion batteries, but include Li / AL-lithium-containing manganese dioxide secondary batteries as water-insoluble secondary batteries, lithium polymer electrolyte secondary batteries, and the like. Further, various batteries such as a nickel-cadmium battery, a nickel-hydrogen battery, a nickel-zinc battery, and a nickel-iron battery as an aqueous secondary battery are included.
In recovering valuable metals from waste batteries, a wet smelting process may be performed in addition to the dry smelting process, but the method for recovering valuable metals according to the present invention relates to the dry smelting process.
The present invention is not limited to the following embodiments, and various modifications can be made without changing the gist of the present invention.

<< Outline of the Valuable Metal Recovery Method According to the Present Invention >>
As shown in FIG. 1, the valuable metal recovery method according to the present invention includes a roasting step S1 for roasting a waste battery to obtain a roasted product, a crushing step S2 for crushing the roasted product to obtain a crushed product, and crushing. In the reduction melting step S6, a sieving step S4 for sieving a product and separating it into a sieving product and a sieving product and a reduction melting step S6 for reducing and melting the sieving product to obtain a reduced product and a slag are essential steps. A induction furnace is used, and a massive carbonaceous reducing agent is added to the induction furnace. In the valuable metal recovery method of the present invention, the magnetic selection step S3 for removing iron as a magnetic deposit and the sieve are subjected to. The oxidative roasting step S5 for oxidative roasting may be carried out, but both of these steps are optional.

In the present invention, the waste battery is not only the used battery itself of the lithium ion battery and the above-mentioned various batteries, but also a defective product generated in the manufacturing process such as a positive electrode material constituting a secondary battery, a residue inside the manufacturing process, and lithium. This is a concept that includes waste materials such as waste generated in the manufacturing process of an ion battery. These waste batteries contain valuable metals such as copper, nickel and cobalt, for example.

In the present invention, a technique is used in which an induction furnace is used when reducing and melting a waste battery, and a massive carbonaceous reducing agent is put into the furnace to generate heat of the carbonaceous reducing agent by induction heating and raise the temperature inside the furnace. It is the principle.
According to the technical principle of the present invention, when the massive carbonaceous reducing agent put into the furnace by induction heating generates heat, the reduction reaction of the waste battery in the furnace proceeds and metal is generated. The metal generated at the same time receives the induction heating of the induction furnace and generates heat, and the temperature inside the furnace rises. It is also possible to melt slag that cannot be induced and heated by this heat generation.
Through these series of actions, it is possible to both generate metal and raise the temperature inside the furnace, and melt the waste battery while reducing it. In this way, a metal containing a valuable metal can be obtained efficiently and inexpensively.

A hydrometallurgical process may be carried out in a subsequent step on the metal obtained through the above-mentioned pyrometallurgical process, thereby removing impurity components and removing valuable metals such as copper, nickel and cobalt. Each can be separated and purified and recovered. The treatment in the hydrometallurgy process can be carried out by a known method such as a neutralization treatment or a solvent extraction treatment.

<< Details of the Valuable Metal Recovery Method According to the Present Invention >>
FIG. 1 shows an example of a valuable metal recovery method according to the present invention, and steps S1 to S6 will be described in order based on the figure.

(Roasting process: S1)
The main purpose of the roasting step S1 is to make the waste battery harmless and to make it easier to crush in the next step. The roasting conditions are not particularly limited, but it is preferable to heat the roasting conditions to 700 ° C. or higher in order to ensure detoxification and to make the roasting brittle and easy to crush. In addition, if the waste batteries are stacked too much, the inside cannot be sufficiently roasted and uneven roasting occurs. Therefore, it is necessary to pay attention to the processing amount and the heating capacity of the furnace so that the waste batteries can be roasted uniformly. The heating method at the time of roasting is not particularly limited, and may be an electric type or a burner type. Burner heating is preferable in terms of low cost.

(Crushing process: S2)
In the crushing step S2, the roasted product roasted in the roasting step S1 is finely crushed to separate each member in the waste battery. The crusher is not particularly limited in the present invention. For example, a known crusher such as a rod mill or a vibration mill may be used. A chain mill is also preferable because it can efficiently crush waste batteries. Since there are various types and shapes of waste batteries, an appropriate crusher may be selected according to the purpose.

(Magnetic separation process: S3)
Implementation of the magnetic separation step S3 is optional. When the magnetic separation step S3 is carried out, it may be carried out after the crushing step S2 or after the sieving step S4 described later.
The purpose of magnetic separation is to remove metals such as iron, which is a magnetic substance. If iron is contained in the valuable metal, the design of the melting point and viscosity of the slag becomes complicated during pyrometallurgy, and if iron cannot be sufficiently removed, processing costs will be incurred in the wet process of the subsequent process. Because. When magnetic separation is performed, the melting point and viscosity of the slag can be easily designed, and when iron is sufficiently removed, the processing cost in the wet process of the subsequent process can be reduced.
The magnetic separator is not particularly limited, but a known hanging magnetic separator can be used.

(Sieve step: S4)
The sieving step S4 may be performed after the crushing step S2, or may be performed after the magnetic separation step S3. In the sieving step S4, the crushed product is separated into a sieving product and a sieving product by a sieving machine. The opening of the sieve may be determined according to the type and shape of the waste battery to be crushed. If the opening is too large, a large amount of non-valuable metal as well as valuable metal will be recovered under the sieve, which is not preferable. Further, if the opening is too small, a large amount of valuable metal is contained on the sieve, which is not preferable. Generally, it is preferable that the spread of the sieve is 0.5 mm or more and 5 mm or less because valuable metals can be efficiently recovered.
Since valuable metals such as nickel and cobalt are mainly contained in the positive electrode active material, they are recovered in powder form and are therefore contained in the sieve.

(Oxidation roasting process: S5)
Implementation of the oxidative roasting step S5 is optional. When the oxidative roasting step S5 is carried out, the sieved product (powder) recovered in the sieving step S4 is oxidatively roasted in the oxidative roasting step S5. By oxidative roasting, components that can be reducing agents in the waste battery can be oxidized, whereby the quality of the waste battery can be made uniform. When oxidative roasting is performed, the residual reducing agent ratio can be stably suppressed to a low level, which makes it easier to control the degree of reduction in the reduction melting step of the next step.

(Reduction melting step: S6)
In the reduction melting step S6, the sieve product which is a crushed product of the waste battery or the sieve product which has been oxidized and roasted is reduced and melted. This reduction melting produces metals and slags containing valuable metals. An induction furnace is used in the reduction melting step S6 of the present invention. If the induction furnace is used, the waste battery can be efficiently melted, the degree of reduction can be realized according to the purpose, and therefore the valuable metal can be efficiently recovered.

FIG. 2 shows an induction furnace IF used for melting a waste battery. The present invention is characterized in that a massive carbonaceous reducing agent is put into the induction furnace together with a waste battery and reduced and melted in the induction furnace IF. The induction furnace IF itself may be a known one. The illustrated induction furnace IF has a furnace 1 in which a lining material 1 is attached in a crucible shape, a coil 2 arranged on the outer periphery of the furnace 1, and a joint iron (yoke) 3 arranged on the outside of the coil 2. A plug 4 is provided in the furnace so that a furnace lid 5 can be placed on the upper surface of the furnace, and such an induction furnace IF can be used.
By putting a massive carbonaceous reducing agent and a waste battery into the furnace 1 in the induction furnace IF, the carbonaceous reducing agent is heated by an induced current, and the reduced carbonaceous reducing agent promotes the reduction reaction of the waste battery. Will be done.

Further, as the reduction reaction progresses, a metal containing a valuable metal and slag are generated, but since the metal is heated by the induced current, the temperature rises efficiently. In addition, heat is not generated in the slag where no current originally flows, but by adding the carbonaceous reducing agent as a lump, heat is also generated in the slag portion of the contact portion between the slag and the lumpy carbonaceous reducing agent.

As described above, in the present invention, a large number of carbonaceous reducing agents, which are heat generating sources, are dispersed in the furnace 1 to promote heat generation and reduction in parallel. By repeating the cycle of reducing the waste battery with a reducing agent → generating metal → heating the metal with an induced current, the temperature inside the furnace rises efficiently and reduction melting proceeds.
By using the massive carbonaceous reducing agent as in the present invention, the frequency of contact between the molten waste battery and the reduced product is increased, and the effect that the reduction reaction proceeds efficiently can be obtained.

In the present invention, among the reducing agents, a carbonaceous reducing agent is particularly used. The reducing agent, there are various including oxides such as hydrogen compounds and CO, such as H 2 _S, in the present invention, it is selected carbonaceous reducing agent typified carbon, coal, coke. The reason is excellent controllability of the reduction reaction. That is, the carbon contained in the waste battery contributes as a reducing agent and promotes the reduction reaction. If the reducing agent to be added is also a homogeneous carbonaceous substance, the same reduction reaction will occur, so that the reduction reaction can be easily controlled, and thus temperature control and atmosphere control can be easily performed. It should be noted that a method of using CO gas is conceivable, but there is a problem of equipment cost and safety. Hydrogen compounds have similar problems.
Examples of the carbonaceous reducing agent include coal, carbon, and coke.

It is preferable that the bulk carbonaceous reducing agent used in the present invention has a small size because the chance of contact with the processed product increases and the treatment proceeds uniformly.
However, if the size of each mass is ^{extremely small, for example, less than 1 cm 3, the} heat generated by the induced current is not sufficiently generated, and the heating effect is consumed while being insufficient, so that the effect is reduced. On the other hand, the induced current is generated on the surface of the carbonaceous reducing agent and generates heat, and the heat generation cannot be effectively utilized even if an excessively coarse carbonaceous reducing agent is used.
Therefore, carbonaceous reducing agent massive to be added is an individual volume of ^{1cm 3 ~1000cm} 3, it is preferred that preferably ^{5cm 3 ~500cm} 3. In this case, heat is sufficiently generated, and the amount of heat generated per surface area from the reducing agent is also large.

Further, the amount of the bulky carbonaceous reducing agent to be added should be in the range of 0.1% by mass or more and 18% by mass or less, assuming that the total amount of the reducing agent and the slag discharged from the induction furnace is 100% by mass. It is preferable to control. If it is less than 0.1% by mass, the amount of addition is small and the effect of addition does not appear sufficiently, and if it exceeds 18% by mass, reduction proceeds too much even if there is no reducing agent in the waste battery, and iron, manganese, etc. are unnecessary. A large amount of metal is generated and mixed with the valuable metal, which is not preferable. Within the above range, the frequency of contact between the molten waste battery and the reduced product increases, and the reduction reaction proceeds efficiently, which is preferable.

Further, the massive carbonaceous reducing agent preferably has a carbon grade of 65% by mass or more, preferably 95% by mass or more. If it is less than 65% by mass, the reduction efficiency is low and a large amount of impurities may be mixed in, which is not preferable. However, if it is in the above range, the reduction efficiency is high and impurities are less mixed, which is preferable.

Since the surface of the massive carbonaceous reducing agent is affected by the heat generated by electromagnetic induction, if the required amount of carbonaceous reducing agent is small, the carbonaceous material is concentrated on the surface and the central part is hollow in order to secure the calorific value. A carbonaceous reducing agent having a structure of the above may be used.

In industrial operations, a general operation method is to continuously supply and discharge waste batteries and a carbonaceous reducing agent to an induction furnace. In such a case, the carbonaceous reducing agent at the time of starting operation is used. The amount of addition can be adjusted according to the amount of reducing agent and slag theoretically calculated from the contents inside the furnace, and the amount of addition can be adjusted during operation.

(Post-process of recovery method according to the present invention)
The metal obtained by the recovery method of the present invention is separated into highly pure valuable metals by performing a wet treatment in a subsequent step, for example, by dissolving it in an acid and separating impurities by a method such as neutralization, solvent extraction or electrowinning. Can be collected.

Hereinafter, the present invention will be described in more detail with reference to Examples 1 to 18 and Comparative Example 1.

(Roasting process)
As the lithium-ion battery as a waste battery, a used product of what is generally called a square battery for automobiles was used. This waste battery was roasted in the air at a temperature of 900 ° C. for 5 hours to obtain a roasted product.

(Crushing process)
Next, in the crushing step, the roasted product was crushed at a rate of 12 kg / batch for 35 seconds using a chain mill.
The crushed material obtained by the crushing treatment was recovered and subjected to magnetic separation in the following magnetic separation step.

(Magnetic separation process)
A commercially available hanging magnetic separator was used as the magnetic separator. For each sample, the crushed material was supplied to a magnetic separator having a magnetic force of 3000 G at a supply rate of 4.5 kg / min and magnetically separated to separate a magnetic material such as iron and a non-magnetic material.

(Sieve process)
The above non-magnetic material was sieved using a continuous vibrating sieve.
The mesh size of the sieve was 3.0 mm, and the supply rate was 2.5 kg / min.
The sieved product was subjected to oxidative roasting in the next oxidative roasting step.

(Oxidation roasting process)
For oxidative roasting, a kiln having a diameter of 20 cm in the furnace and an effective length of 100 cm in the furnace was used. The sample supply rate was 2.0 kg / min, and the sample was roasted in the air for 3 hours while maintaining the temperature inside the furnace at 750 ° C. The obtained oxidized roasted product (sieving product) was subjected to a reduction melting step of the next step.

(Reduction melting process)
An induction furnace having a capacity of 60 liters was used for the reduction melting of the oxidative roasted product (sieving product). The amount processed at one time in the induction furnace was 10.0 kg.
In Table 1, 0.80 kg of a massive carbonaceous reducing agent was added in Examples 1 to 10. In Comparative Example 1, no bulk carbonaceous reducing agent was added.
The size (volume) of the charged bulk carbonaceous reducing agent was increased in order from Example 1 to Example 8 as shown in Table 1. The carbon grade of each of the massive carbonaceous reducing agents is 90% by mass.
In Examples 9 and 10, the size (volume) of ^{the massive carbonaceous reducing agent is 110 cm 3} , but the carbon grade of the massive carbonaceous reducing agent is 65% by mass in Example 6 and 99% by mass in Example 7. %.

(Evaluation)
As evaluation criteria, whether or not each sample could be melted, whether or not the melting time was short or long, and whether or not the produced metal could be recovered were used as guidelines. The results are shown in Table 1.
In Examples 1 to 10, the sample was heated with a massive carbonaceous reducing agent, reduced and melted, and metal was produced and recovered. On the other hand, in Comparative Example 1 in which the bulk carbonaceous reducing agent was not added, the waste battery did not melt.

As shown in Examples 1 to 8, when the carbon grade (mass%) of the massive carbonaceous reducing agent is the same, the larger the size of the massive carbonaceous reducing agent, the shorter the time the waste battery melts. That is, as shown in Examples 1 to 8, the larger the amount of the bulk carbonaceous reducing agent charged, the faster the melting time.
Further, when the size (volume) of the massive carbonaceous reducing agent is the same as compared with Examples 9 and 10, the higher the carbon grade (mass%) of the massive carbonaceous reducing agent, the shorter the time the waste battery melts. did.

As shown in Table 2, in Examples 11 to 15, the size (volume) of the bulk carbonaceous reducing agent was set to 80 cm ³ , and the carbon grade of the bulk carbonaceous reducing agent was unified to 85% by mass, and carbonaceous reduction was performed. The amount of the agent was 0.1% by mass, 2% by mass, 7% by mass, 15% by mass, and 18% by mass, assuming that the total amount of the reducing agent and the slag discharged from the induction furnace was 100% by mass.
In Examples 11 to 15, the frequency of contact between the molten waste battery and the reduced product increased, and the reduction reaction proceeded efficiently. This can be seen from the fact that the melting time is shorter than that of Comparative Example 1.
However, looking at the tendency of the contents of iron and manganese in the metal, which are impurities of Examples 11 to 15 shown in Table 3, to be generated, the amount of the massive carbonaceous reducing agent used is less than 0.1% by mass. In Example 11, it is presumed that the reduction reaction does not proceed effectively. Further, in Example 15 in which the amount of the massive carbonaceous reducing agent used exceeds 18% by mass, it is presumed that the reduction proceeds too much and a large amount of unnecessary metals such as iron and manganese are produced.

As shown in Table 2, in Examples 16 to 18, the size (volume) of the ^{carbonaceous reducing agent was unified to 60 cm 3} , and the amount of the carbonaceous reducing agent was unified to 8.0%. Then, the carbon grades of the carbonaceous reducing agent were set to 65% by mass, 80% by mass, and 95% by mass, respectively.
In Examples 16 to 18, the reduction efficiency was high, and the amount of impurities mixed was relatively small. However, looking at the tendency of the melting time of Examples 16 to 18, it is presumed that when the carbon grade shown in Example 16 is less than 65% by mass, the melting time tends to be long.

As can be seen from each of the above examples, by using the recovery method of the present invention, it was possible to efficiently melt the waste battery and recover the metal. In addition, valuable metals such as cobalt, nickel, and copper could be recovered from the obtained metal by subjecting it to the hydrometallurgy process in the subsequent process.

According to the present invention, cobalt, nickel, and copper can be reused in various industries and can be reused as a raw material for a lithium ion battery.

1 Lining material 2 Coil 3 Joint iron (yoke)
4-plug IF induction furnace

Claims (7)

The roasting process of roasting waste batteries to obtain roasted products,
A crushing step of crushing the roasted product to obtain a crushed product,
A sieving step of sieving the crushed material and separating it into a sieve product and a sieve product.
In a method for recovering valuable metals from a waste battery by subjecting the sieve to a process having a reduction melting step of reducing and melting the reduced product and slag.
The furnace used in the reduction melting step is an induction furnace.
A method for recovering valuable metals from a waste battery, which comprises adding a massive carbonaceous reducing agent to the induction furnace. The amount of the bulky carbonaceous reducing agent to be added is controlled so as to be in the range of 0.1% by mass or more and 18% by mass or less, assuming that the total amount of the reducing substance and the slag discharged from the induction furnace is 100% by mass. The method for recovering valuable metals from a waste battery according to claim 1, wherein the method is characterized by the above. Valuable metal recovery process from the waste battery according to claim 1 or 2, wherein the carbonaceous reducing agent massive added is the size of 1cm ³ ~1000cm ^3. The method for recovering valuable metals from a waste battery according to claim 1, 2, or 3, wherein the composition of the lumpy carbonaceous reducing agent to be added is 65% by mass or more of carbon grade. The method for recovering valuable metals from a waste battery according to claim 1, wherein the magnetic separation step for removing iron as a magnetic deposit is performed before or after the sieving step. The method for recovering valuable metals from a waste battery according to claim 1 or 5, wherein the oxidative roasting step of oxidatively roasting the sieved product is performed before the reduction melting step. The method for recovering a valuable metal from a waste battery according to claim 1, 2, 3, 4, 5 or 6, wherein the valuable metal to be recovered is at least one selected from cobalt, nickel, and copper.

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