JP7355713B2 - Pretreatment method for recovering valuable elements from secondary batteries and method for recovering valuable elements from secondary batteries - Google Patents

Description

The present invention relates to a pretreatment method for recovering valuable elements such as Co, Ni, and Fe from secondary batteries, and a method for recovering valuable elements from secondary batteries .

In recent years, as environmental regulations have become stricter, renewable energy is expected to increase in the future, and as electrification advances to improve vehicle fuel efficiency, secondary batteries are expected to become even more important. There is. For example, the mainstream secondary batteries currently in use are lithium ion batteries (LIB) and nickel metal hydride batteries (Ni-MH), and demand for these secondary batteries is expected to increase in the future.

Here, secondary batteries such as LIB and Ni-MH use rare metals (valuable metals) such as cobalt and nickel, but these rare metals have problems such as the global ubiquity of their resources. The risk of resource depletion has been pointed out. Furthermore, with regard to cobalt, there have been rumors of unfair labor conditions in mines, and there is a possibility that mining alone will not be able to fully meet the demand.

From these viewpoints, recycling technology for rare metals such as cobalt and nickel is attracting attention. However, currently, wet solvent extraction is the main method, and large-scale processing technology has not been established due to cost issues. Therefore, there is a need for a technology that can inexpensively and efficiently recover valuable metals from LIBs that use cobalt and nickel. High-temperature refining technology (hereinafter referred to as pyrometallurgical refining technology) used in the steelmaking process is relatively inexpensive, and is used in various industries such as automobiles and electrical equipment to meet social recycling issues. It is considered that there is an urgent need to establish the technology so that it can be used in various fields.

For example, Patent Document 1 discloses a technique for heating recovered valuables in a non-oxidizing atmosphere to remove carbon without substantially oxidizing valuable metals in the valuables.
Additionally, Patent Document 2 discloses a technique for recovering lithium, cobalt, and other metals from lithium batteries.
Further, Patent Document 3 discloses a technique for separating crushed materials and magnetically separating the separated collected materials.

Furthermore, Patent Document 4 discloses a technique in which Cu, Al, Fe and active materials of positive and negative electrodes are separated, and the separated recovered materials are subjected to magnetic separation.

Japanese Patent Application Publication No. 2002-32715 Japanese Patent Application Publication No. 2012-112027 Japanese Patent Application Publication No. 2014-199774 JP2012-229481A

By the way, the technology for recovering cobalt, nickel, etc. from LIB recovered materials requires a process to remove unnecessary metal elements such as Cu contained in LIB recovered materials before actually recovering cobalt, nickel, etc. Become. This is because when recovering cobalt, nickel, etc., a process such as reducing oxides is performed, but if the metal contains elements other than cobalt or nickel, the metal may This is because the returned cobalt and nickel will be mixed with other metals, reducing recovery efficiency. Therefore, in the process of recovering cobalt, nickel, etc. from LIB recovered materials, a step of removing Cu etc. from the recovered materials is performed as a pre-treatment step.

However, Patent Document 1 does not describe at all that a pretreatment step is performed before heating.
Further, Patent Document 2 does not describe the removal of Cu, and although magnetic separation is exemplified as a physical separation, it does not disclose at all the optimal magnetic separation conditions for removing Cu.

Furthermore, Patent Document 3 and Patent Document 4 do not disclose at all the optimum magnetic separation conditions for removing Cu, similar to Patent Document 2.
In other words, although it is necessary to improve the yield of valuable elements and reduce harmful elements throughout the entire LIB recycling process, the above-mentioned Patent Documents 1 to 4 do not stipulate the magnetic separation conditions to be performed as a pretreatment before recycling valuable elements. Not yet. Furthermore, although Patent Documents 1 to 4 describe the strength of the magnetic field (magnetic flux density), they do not describe detailed conditions such as centrifugal acceleration, and it is highly unlikely that Cu will be removed from LIB even if used as is. Can not.

The present invention was made in view of the above-mentioned problems, and by magnetically sorting the recovered material containing waste LIB powder before reduction, Cu is reliably removed from the recovered material in advance, and the Cu is removed. The purpose of the present invention is to provide a pretreatment method for recovering valuable elements from a secondary battery and a method for recovering valuable elements from a secondary battery, which can recover Co and Ni from the removed recovered material with a high yield. shall be.

In order to solve the above problems, the pretreatment method for recovering valuable elements from the secondary battery of the present invention takes the following technical measures.
That is, the pretreatment method for recovering valuable elements from a secondary battery of the present invention involves treating a secondary battery with at least one of nickel or cobalt and aluminum obtained through at least crushing and sieving treatments. Alternatively, when recovering nickel and cobalt by reducing nickel and cobalt on recovered materials containing at least one of copper, magnetic separation is performed in a drum-type magnetic separator as a pretreatment, and the magnetic flux density on the drum surface is B[G] The method is characterized in that magnetic separation is carried out under conditions such that the relationship between the centrifugal acceleration a [m/s ² ] that the recovered material receives satisfies the following equations (1) to (4).

B≦198.9a+1085.7...Formula (1)
B≦-764.4a+16912.3...Formula (2)
B≦3000...Formula (3)
B≧1170...Formula (4)
In addition, the method for recovering valuable elements from a secondary battery of the present invention includes a method for collecting a magnetic material containing at least one of nickel and cobalt, which has been obtained through at least a crushing process, and aluminum and This is a method in which magnetic materials are magnetically separated from recovered materials containing non-magnetic materials containing one or more types of copper using a drum-type magnetic separator, and the magnetic materials are subjected to a chemical reaction to recover one or more types of nickel and cobalt. The magnetic separator is operated under conditions such that the relationship between the magnetic flux density B [G] on the drum surface and the centrifugal acceleration a [m/s ² ] that the collected material receives satisfies the following equations (1) to (4). It is characterized by magnetic separation.

B≦198.9a+1085.7...Formula (1)
B≦-764.4a+16912.3...Formula (2)
B≦3000...Formula (3)
B≧1170...Formula (4)

According to the pretreatment method for recovering valuable elements from secondary batteries of the present invention, by magnetically sorting the recovered material containing waste LIB powder before reduction, Cu can be reliably removed from the recovered material in advance. Co and Ni can be recovered at a high yield from the recovered material from which Cu has been removed.

FIG. 1 is a schematic diagram showing a magnetic separator used in the pretreatment method of the present invention. FIG. 3 is a diagram showing the relationship between centrifugal acceleration a that the recovered material receives and magnetic flux density B on the surface of the magnetic separation drum.

EMBODIMENT OF THE INVENTION Hereinafter, the embodiment of the pretreatment method (hereinafter simply referred to as pretreatment method) for recovering valuable elements from a secondary battery according to the present invention will be described in detail based on the drawings.
As shown in FIG. 1, the pretreatment method of this embodiment is a method for recovering valuable elements in which valuable metals are recovered in the form of single metals, alloys, or salts from recovered secondary batteries using chemical reactions. On the other hand, it performs pretreatment for this recovery method, and adjusts the raw materials to be processed in the recovery method.

Specifically, the recovery method of this embodiment is to recover a recovered material containing valuable elements obtained by subjecting a secondary battery to heating, crushing, sieving, and magnetic separation. In the above chemical reaction, the metal and oxide are separated from the mixture by mixing with a reducing agent and heating to reduce and metalize the valuable elements and melting, and after cooling, the metal is separated from the oxide. A method may be used in which the material is sorted and collected, or a method in which an aqueous solution prepared by dissolving the collected material in an acid is subjected to electrodeposition may be used.

In the pretreatment method of the present invention, one or more of nickel and cobalt is obtained by subjecting a secondary battery to at least a crushing treatment, and more specifically, a heating, crushing, and sieving treatment. When reducing and recovering nickel and ^/ or cobalt from a recovered material containing ] Magnetic separation is performed under conditions such that the following equations (1) to (4) are satisfied.

Here, oxides such as Ni, Co, and Li are used in waste Li-ion batteries. Since these elements such as Ni, Co, and Li are rare and valuable, it is desirable to recover them as much as possible. For example, methods for recovering oxides such as Ni, Co, and Li include pyrometallurgy such as gas/charcoal reduction, and hydrometallurgy such as electrolysis/extraction. Among these, pyrometallurgical refining generally has lower operating costs than hydrometallurgical refining, and further development is expected in the future.

However, one of the challenges when recovering valuable metals through pyrometallurgy is the separation of Cu, which is used in the negative electrode foil of LIBs (lithium-ion batteries), and Al, which is used in the positive electrode foil. In other words, if Cu and the like remain in the LIB recovered material during reduction, the metals will be mixed together after the reduction process, making it difficult to remove only Cu and the like. Therefore, it is desirable to remove only Cu and the like from the recovered material before the reduction step.

Note that separation and recovery of Cu and the like in hydrometallurgical refining is easier than in pyrometallurgy. However, since the operating cost of hydrometallurgical refining is generally higher than that of pyrometallurgy, it is preferable to reduce the amount of recovered material processed by hydrometallurgy as much as possible. In this respect as well, if Cu and the like are separated in advance, it is possible to reduce the amount of recovered material brought into hydrometallurgy, and it is possible to relatively reduce the operating cost of hydrometallurgy.

Therefore, in the pretreatment method of the present invention, a secondary battery is treated with a magnetic material containing at least one of nickel and cobalt and a non-magnetic material containing at least one of aluminum and copper, which are obtained through at least a crushing process. In order to recover one or more of nickel and cobalt from the collected materials containing the magnetic materials by chemically reacting the magnetic materials, as a pretreatment, the magnetic flux density B [G] on the drum surface and the centrifugal acceleration a [m /s ² ] under conditions that satisfy the following equations (1) to (4), Cu and Al can be efficiently removed before recovering Ni and Co. By selectively removing only Cu and Al as a process, the reduction in recovery efficiency and value (purity) of recovered valuable elements in dry or wet processes is suppressed.

B≦198.9a+1085.7...Formula (1)
B≦-764.4a+16912.3...Formula (2)
B≦3000...Formula (3)
B≧1170...Formula (4)
Next, the recovered material used in the pretreatment method of this embodiment, the equipment (magnetic separator 1) used in the pretreatment method, and the contents of the pretreatment step performed using this equipment will be described in detail.

Since Ni and Co mentioned above are magnetic (ferromagnetic) elements, if they are placed in the presence of a magnetic field in a pretreatment method, they will receive magnetic force. On the other hand, unlike Ni and Co, Cu and Al are elements that do not have magnetism, so they do not generate magnetic force even in the presence of a magnetic field. That is, by utilizing the presence or absence of magnetic force, it is possible to selectively separate magnetic components such as Ni and Co from components mainly containing non-magnetic Cu and the like. The above-mentioned pretreatment method utilizes this difference in magnetism between components or elements.

Note that various methods are known for sorting by magnetic force, such as a belt method, a hanging method, a cylinder method, and a drum method, and the drum method is adopted in the pretreatment method of this embodiment. The drum-type magnetic separator 1 uses both magnetic force and centrifugal force to collect the magnetic material 4 from the collected material with high collection efficiency.
As shown in FIG. 1, the above-mentioned drum-type magnetic separator 1 includes a magnetic separator drum 2 that rotates around an axis facing in the horizontal direction, a feeder 3 that supplies collected materials onto the magnetic separator drum 2, and a magnetic separator drum 2 that are separated from each other. It has a magnetic material collecting section 5 that collects the magnetic material 4 that has been collected, and a non-magnetic material collecting section 7 that collects the non-magnetic material 6 separated by the magnetic separation drum 2.

The feeder 3 includes a hopper 8 into which recovered materials containing nickel and cobalt obtained through crushing and sieving processes can be input, and a conveyor section 9 that conveys the recovered materials introduced from the hopper 8 to the magnetic separation drum 2. It has . Specifically, the above-mentioned hopper 8 is formed in a tapered shape that widens toward the top, and is open both above and below, and collects collected materials input from above. The recovered materials can be fed onto the conveyor section 9. Further, the conveyor section 9 is arranged substantially parallel to the horizontal direction, so that the collected items can be transported in the horizontal direction. In other words, the conveyor section 9 includes a head pulley and a tail pulley that are spaced apart from each other in the horizontal direction, and a belt that is passed around between these two pulleys. The conveyor section 9 places the collected material inputted from the feeder 3 on a belt that moves horizontally from the tail pulley toward the head pulley, and moves it to the upper part of the magnetic separation drum 2, more specifically, to the upper side of the rotation axis. Collected materials can be conveyed to the surface of the magnetic separation drum 2 located there.

The magnetic selection drum 2 described above is a cylindrical member with a hollow interior, and is arranged rotatably around an axis facing in the horizontal direction. A magnet 10 is disposed inside the hollow part of the magnetic separation drum 2, so that a magnetic force can be applied to the raw material supplied to the surface of the magnetic separation drum 2. Further, a motor (not shown) is attached to the magnetic separation drum 2 so that it can be driven to rotate around an axis facing in the horizontal direction.

A plurality of magnets 10 provided inside the magnetic separation drum 2 described above are arranged at equal distances from the surface in the axial direction. These plurality of magnets 10 are arranged in a circular arc shape centered on the axis, and can generate magnetic force of the same strength evenly on the surface of the magnetic selection drum 2.
These magnets 10 extend half a circumference (angle They are arranged in a semicircular arc over a range of 180 degrees. Further, these magnets 10 are fixed in a non-rotatable state so as not to rotate together with the magnetic selection drum 2. Note that these magnets 10 may be permanent magnets or electromagnets.

The magnetic material collection unit 5 includes a magnetic material collection hopper 11 that collects the magnetic material 4 falling from the surface of the magnetic separation drum 2, and stores the magnetic material 4 collected by the magnetic material collection hopper 11. It has a magnetic object storage section 12. The non-magnetic material collecting section 7 includes a non-magnetic material collection hopper 13 that collects the non-magnetic material 6 falling from the surface of the magnetic separation drum 2, and a non-magnetic material collection hopper 13 that collects the non-magnetic material 6 falling from the surface of the magnetic separation drum 2. It has a non-magnetized article storage section 14 that stores the kimono 6.

Specifically, the non- magnetic material collecting section 7 is provided below the outer circumferential surface located on the side in the direction of rotation when viewed from the rotation axis of the magnetic separation drum 2, and extends vertically downward. Falling non- magnetic objects 6 are collected. Also , the magnetic object collecting section 5 is located just below the rotation axis when viewed from the rotation axis of the magnetic separation drum 2, and the magnetic material collecting section 5 is located just below the rotation axis when viewed from the rotation axis of the magnetic separation drum 2 . Collecting Kimono 4 .

Specifically, in the magnetic separator 1 described above, magnetic separation is performed as follows.
That is, among the collected materials supplied to the surface of the magnetic separation drum 2, components (magnetic materials 4) containing magnetic metals such as Ni, Co, and Fe or metal oxides (metal compounds) are treated with the magnet 10 described above. A magnetic force is generated under the influence of the magnetic field, and these magnetic objects 4 are magnetically attached to the surface of the magnetic selection drum 2. On the other hand, components containing non-magnetic metals such as Cu or metal oxides (metal compounds) (
The above-mentioned magnetic force is not generated in the non-magnetic objects 6), and these non-magnetic objects 6 are simply placed on the surface of the magnetic separation drum 2 (because they are not magnetically attached, they can be removed by turning them upside down). state).

Note that even if the non-magnetic material 6 is only placed on the surface of the magnetic separation drum 2, as long as the non-magnetic material 6 is supported by the surface of the magnetic separation drum 2 located below, the non-magnetic material 6 will be placed on the surface of the magnetic separation drum 2. There will be no departure from.
However, as the magnetic separation drum 2 rotates and the positions of the magnetic objects 4 and non-magnetic objects 6 on the magnetic separation drum 2 move downward, the positions of the magnetic objects 4 and non-magnetic objects 6 and the position of the magnetic separation drum 2 change. The relationship changes, and it becomes difficult to support the magnetic objects 4 and non-magnetized objects 6 on the surface of the magnetic separation drum 2 located below. For example, consider a case where the position of the magnetic object 4 or the non-magnetic object 6 changes to the side of the rotation axis of the magnetic separation drum 2. In this case, there is no surface of the magnetic separation drum 2 that should support the magnetic objects 4 and non-magnetized objects 6 on the lower side. In addition, gravity acts downward on the magnetic material 4 and non-magnetic material 6, and force acts in a direction to peel off the magnetic material 4 and non-magnetic material 6 from the surface of the magnetic selection drum 2.

In addition, even if gravity acts, since the magnetic force acts on the magnetic object 4, it will not be easily peeled off from the surface of the magnetic selection drum 2. However, the non-magnetized material 6 on which no magnetic force is applied is easily peeled off from the surface of the magnetic separation drum 2 due to gravity.
Therefore, the non-magnetic material 6 detaches from the surface of the magnetic separation drum 2 at a lateral position on the rotation direction side when viewed from the rotation axis of the magnetic separation drum 2, and falls downward (in the normal direction). On the other hand, since the magnetic force acts on the magnetic object 4 as described above, the magnetic object 4 is detached from the surface of the magnetic separation drum 2 until the magnetic separation drum 2 rotates further and reaches a position where the gravity exceeds the magnetic force. There's nothing to do.

Specifically, the magnetic material 4 is detached from the surface of the magnetic separation drum 2 at a position on the lower side in the direction of rotation (about 4 o'clock to 5 o'clock on the hour hand of a clock) when viewed from the rotation axis. , it falls while approaching in the direction returning toward the rotation axis.
In this way, in the magnetic separator 1 of the present embodiment, the magnetically attracted material 4, that is, components containing metals such as Ni, Co, and Fe or metal oxides (metal compounds), are collected in the magnetically attracted material collecting section 5. . Further, non-magnetized matter 6, that is, a component containing a metal such as Cu or a metal oxide (metal compound), is collected in the non-magnetized matter collecting section 7.

When performing magnetic separation using the magnetic separator 1 described above, whether the magnetic materials 4 and the non-magnetic materials 6 are efficiently separated depends on the centrifugal acceleration a that the collected materials supplied to the surface of the magnetic separation drum 2 receive, and the drum It is affected by the surface magnetic flux density B, etc.
For example, when the centrifugal acceleration a to which the collected material is subjected is large, the centrifugal force applied to the collected material also becomes large, making it easier for the collected material to separate from the surface of the magnetic separation drum 2. Also, when the magnetic flux density B on the drum surface is small, the magnetic force that attracts the recovered material to the magnetic separation drum 2 becomes small, and the recovered material becomes easier to separate from the surface of the magnetic separation drum 2, as in the case of centrifugal acceleration a.

On the other hand, when the centrifugal acceleration a applied to the collected material is small, the centrifugal force applied to the collected material also becomes small, making it difficult for the collected material to separate from the surface of the magnetic separation drum 2. Also, when the magnetic flux density B on the drum surface is large, the magnetic force that attracts the collected materials to the magnetic separation drum 2 becomes large, making it difficult for the collected materials to separate from the surface of the magnetic separation drum 2, as in the case of centrifugal acceleration a.
Therefore, in the pretreatment method (magnetic separation method) of the present invention, magnetic separation is performed in a drum-type magnetic separator 1 as a pretreatment, and the magnetic flux density B [G] on the drum surface, the centrifugal acceleration a [ m/s ² ] under conditions that satisfy the following equations (1) to (4).

B≦198.9a+1085.7...Formula (1)
B≦-764.4a+16912.3...Formula (2)
B≦3000...Formula (3)
B≧1170...Formula (4)
Specifically, the condition that satisfies all of the above-mentioned formulas (1) to (4) means that the horizontal axis is the centrifugal acceleration a [m/s ² ] that the collected material receives, and the magnetic flux density B [G ] is taken as the vertical axis, the values of magnetic flux density B [G] and centrifugal acceleration a [m/s ² ] are expressed in the trapezoidal range surrounded by the straight lines of equations ( 1 ) to ( 4 ). It's nothing but setting.

Regarding the above-mentioned recovered materials, it is not possible to perform magnetic separation on particles of any particle size, so from the viewpoint that magnetic separation can be carried out, recovered materials with a maximum particle size of 5 mm, preferably 2 mm or less, should be selected. It is preferable to select it as
If magnetic separation is performed under conditions that satisfy all of the above-mentioned formulas (1) to (4), the Cu concentration of the magnetic material 4 collected in the magnetic material collection section 5 can be reduced to 1.6 wt% or less, In addition, the recovery rate (yield) of Co and Ni, which are valuable metals, can be increased to 90% or more, and Cu can be reliably removed from the recovered material in advance, and Co and Ni can be highly recovered from the recovered material from which Cu has been removed. It becomes possible to recover the amount at a yield rate.

Next, the effects of the pretreatment method of the present invention will be explained in detail using Examples and Comparative Examples.
In the Examples and Comparative Examples, waste lithium-ion batteries (LIB) containing nickel, cobalt, aluminum, and copper are crushed and sieved, and the material separated under the sieve is recovered and valuable metals are recovered. , and calculated the recovery rate. More specifically, in the Examples and Comparative Examples, the above-mentioned recovered material was collected using a drum-type magnetic separator 1 (manufactured by Eriez) using a permanent magnet (magnet 10), and the magnetic separator drum 2 was rotated at 10 rpm, 20 rpm, 27 rpm, It is fed into a magnetic separator 1 rotating at rotation speeds of 36 rpm, 40 rpm, 48 rpm, 60 rpm, 66 rpm, 72 rpm, and 80 rpm, and magnetically separated (classified) into magnetic materials 4 and non-magnetic materials 6 in the magnetic separator 1. . The magnetically selected magnetic materials 4 and non-magnetized materials 6 of Examples and Comparative Examples were weighed and then analyzed for Cu, Co, and Ni by ICP analysis. Note that the raw materials before magnetic separation were also analyzed for Cu, Co, and Ni by ICP analysis, and the concentration [wt%] in weight ratio (weight percent) was determined before and after magnetic separation.

Further, the total yield of Co and Ni (total yield of valuable metals) used for evaluation in the Examples and Comparative Examples was calculated by the following formula (5). The total yield of Co and Ni refers to "Co+Ni yield" in Table 1, and is nothing but the sum of "Ni yield" and "Co yield".
Total yield (Co+Ni yield) =
(100 x weight of magnetized material 4 [g] x Co concentration in magnetized material 4 [wt%]
+ 100 x weight of magnetized material 4 [g] x Ni concentration in magnetized material 4 [wt%])
÷(Weight of raw material fed into magnetic separator 1 [g] x Co concentration in original raw material [wt%]
+ Weight of raw material fed into magnetic separator 1 [g] × Ni concentration [wt%]) ... (5)
In addition, the Cu concentration [wt%] obtained in the Examples and Comparative Examples in Table 1 was obtained by ICP analysis of Cu contained in the magnetic material 4 obtained after magnetic separation in the same manner as Co and Ni. It is.

Regarding the Cu concentration obtained by measurement, if it was 1.6wt% or less, it was considered a pass, and if it was greater than 1.6wt%, it was considered a fail. Regarding the calculated total yield, a case of 90% or more was judged as a pass, and a case of lower than 90% was judged as a fail. If both the Cu concentration result and the total yield result were passed, the overall judgment result was determined to be "pass". Furthermore, if either the Cu concentration result or the total yield result was a failure, the overall judgment result was determined to be a "fail".

Table 1 shows the Cu measurement results, total yield (Co+Ni yield), and comprehensive judgment results.

Examples 1 to 8 in Table 1 above satisfy the results of formulas (1) to (4), and the "Cu concentration" is 0.75wt% to 1.56wt%, which is 1.6%. Satisfies the standard of wt% or less. Furthermore, the "total yield" is 92.0% to 99.9%, satisfying the standard of 90% or higher. In other words, Examples 1 to 8, which satisfy all of the results of formulas (1) to (4), have the effect of "reliably removing Cu from the recovered material in advance" and the effect of "reliably removing Cu from the recovered material." The effect of "recovering Ni at a high yield" was satisfactory for both parties, and the test was passed.

On the other hand, in Comparative Examples 1 to 3, the magnetic flux density B is 960 [G], and none of them clearly satisfy Equation (4). Furthermore, in Comparative Example 4, although the magnetic flux density B is 1170 [G], the right side of equation (2) is "-3849.68", and equation (2) is not satisfied. Furthermore, in Comparative Example 5, although the magnetic flux density B is 3000 [G], the right side of equation (1) is "2162.72", which does not satisfy equation (1). Finally, Comparative Example 6 has a magnetic flux density B of 6500 [G], which clearly does not satisfy equation (3).

In other words, Comparative Examples 1 to 6, which cannot satisfy any of Equations (1) to (4), have the effect of "reliably removing Cu from the recovered material in advance" and the effect of "reliably removing Co and Ni from the recovered material." Only one of the two effects was satisfied, namely, "recovery at a high yield rate."
From the above results, if magnetic separation is performed under conditions that satisfy all of the above-mentioned formulas (1) to (4), the Cu concentration of the magnetic material 4 collected in the magnetic material collection section 5 can be reduced to 1.6 wt% or less. It is also possible to increase the recovery rate (yield) of valuable metals Co and Ni to 90% or more. It becomes possible to recover Co and Ni at a high yield.

It should be noted that the embodiments disclosed herein are illustrative in all respects and should not be considered restrictive. In particular, in the embodiments disclosed herein, matters that are not explicitly disclosed, such as operating conditions, operating conditions, various parameters, dimensions, weights, and volumes of components, are beyond the scope of those skilled in the art. Rather, values that can be easily assumed by a person skilled in the art are used.

1 Magnetic separator 2 Magnetic separation drum 3 Feeder 4 Magnetized material 5 Magnetized material collection section 6 Non-magnetized material 7 Non-magnetized material collection section 8 Hopper 9 Conveyor section 10 Magnet 11 Magnetized material collection hopper 12 Magnetized material storage section 13 Non-magnetized material Collection hopper 14 Non-magnetized material storage section

Claims (2)

For secondary batteries, magnetic materials are collected from collected materials obtained through at least crushing treatment that include magnetic materials containing one or more of nickel and cobalt and non-magnetic materials containing one or more of aluminum and copper. In recovering one or more of nickel and cobalt through a chemical reaction, a magnetic substance is obtained from the recovered material using a drum-type magnetic separator as a pretreatment, and the magnetic flux density B [G] on the drum surface, the recovered material When recovering valuable elements from a secondary battery, magnetic separation is performed under conditions such that the relationship between the centrifugal acceleration a [m/s ² ] that the element receives satisfies the following formulas (1) to (4). Pretreatment method.
B≦198.9a+1085.7...Formula (1)
B≦-764.4a+16912.3...Formula (2)
B≦3000...Formula (3)
B≧1170...Formula (4) For secondary batteries, magnetic materials are collected from collected materials that are obtained through at least crushing treatment and include magnetic materials containing one or more of nickel and cobalt and non-magnetic materials containing one or more of aluminum and copper. A method for recovering one or more types of nickel and cobalt by magnetically separating them using a drum-type magnetic separator and chemically reacting the magnetic substances, the method comprising:
The magnetic separator operates under conditions such that the relationship between the magnetic flux density B [G] on the drum surface and the centrifugal acceleration a [m/s ² ] that the collected material receives satisfies the following equations (1) to (4). A method for recovering valuable elements from secondary batteries, which is characterized by sorting.
B≦198.9a+1085.7...Formula (1)
B≦-764.4a+16912.3...Formula (2)
B≦3000...Formula (3)
B≧1170...Formula (4)