Separation apparatus and separation method

Abstract

The present invention provides a separation apparatus and a separation method that can improve the recovery rate of magnetic and non-magnetic substances, which are foreign matter in a mixture. [Solution] The first alternating magnetic field applying unit 6 applies an alternating magnetic field to the mixture 3 while the mixture 3 is being conveyed by the conveying unit 4, thereby lifting the non-magnetic material 5 inside the mixture 3. The second alternating magnetic field applying unit 8 applies a stronger alternating magnetic field to the mixture 3 than the first alternating magnetic field applying unit 6 at the end of the conveying by the conveying unit 4, causing the non-magnetic material 5 lifted inside the mixture 3 to fly, and attracting the magnetic material 7 with the magnetic force of the alternating magnetic field, thereby separating the non-magnetic material 5 and the magnetic material 7 from the mixture 3. The first alternating magnetic field applying unit 6 has a plurality of magnetic field generating units 15 arranged so that the magnetic poles alternately switch along the conveying direction of the mixture 3.

Description

Technical Field

[0001] The present disclosure relates to a separation device and a separation method for separating foreign substances from a mixture.

Background Art

[0002] Conventionally, Patent Document 1 discloses a separation device that generates eddy currents in a mixture to separate aluminum and copper from the mixture. The separation device of Patent Document 1 applies an alternating magnetic field to the mixture being conveyed by a conveying means using a plurality of magnets arranged in series or a magnet capable of switching the magnetic field. As a result, copper with a weak repulsive force against eddy currents and aluminum with a strong repulsive force against eddy currents are separated from the mixture.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, a part of the aluminum or copper to be separated may be located in the lower layer of the mixture. In order to separate the aluminum or copper located in the lower layer of the mixture by eddy currents, not only the strength of the magnetic field applied to the mixture but also the fact that the magnetic field is applied to the mixture for a sufficient time is necessary. However, in Patent Document 1, no consideration is given to the application time of this magnetic field. Therefore, it is not always possible to reliably separate aluminum and copper from the mixture, and there is room for improvement in the recovery rate.

[0005] An object of the present disclosure is to provide a separation device and a separation method capable of improving the recovery rates of magnetic substances and non-magnetic substances, which are foreign substances in a mixture.

Means for Solving the Problems

[0006] A separation device for solving the above problem is a device for separating non-magnetic and magnetic substances contained in a mixture and extracting the material by applying an alternating magnetic field to the mixture during the process of conveying the mixture by a conveying unit, comprising: a first alternating magnetic field applying unit that lifts the non-magnetic substances inside the mixture by applying an alternating magnetic field to the mixture while the mixture is being conveyed by the conveying unit; and a second alternating magnetic field applying unit that, at the end of conveyance by the conveying unit, applies an alternating magnetic field stronger than that of the first alternating magnetic field applying unit to the mixture, causing the non-magnetic substances lifted inside the mixture to fly and attracting the magnetic substances with the magnetic force of the alternating magnetic field, thereby separating the non-magnetic substances and magnetic substances from the mixture, wherein the first alternating magnetic field applying unit has a plurality of magnetic field generating units arranged so that the magnetic poles alternately switch along the conveying direction of the mixture.

[0007] A separation method for solving the above problem is a method for separating non-magnetic and magnetic substances contained in a mixture and extracting the material by applying an alternating magnetic field to a mixture in the process of conveying the mixture by a conveying unit, the method comprising: a step of lifting the non-magnetic substances from the mixture by applying an alternating magnetic field to the mixture from a first alternating magnetic field applying unit having a plurality of magnetic field generating units arranged so that the magnetic poles alternately switch along the conveying direction of the mixture, while the mixture is being conveyed by the conveying unit; and a step of separating the non-magnetic substances and magnetic substances from the mixture by applying a stronger alternating magnetic field to the mixture from a second alternating magnetic field applying unit at the end of conveying by the conveying unit, thereby causing the non-magnetic substances lifted from the mixture to fly and attracting the magnetic substances with the magnetic force of the alternating magnetic field. [Effects of the Invention]

[0008] This disclosure can improve the recovery rate of magnetic and non-magnetic substances, which are foreign matter in a mixture. [Brief explanation of the drawing]

[0009] [Figure 1] This is a configuration diagram of a separation device according to one embodiment. [Figure 2] This is a perspective view of the magnet that constitutes the first alternating magnetic field application unit. [Figure 3] This is an explanatory diagram showing how to determine the magnetic flux density generated in the first alternating magnetic field application unit. [Figure 4] This is a process diagram for separating foreign matter from a mixture. [Figure 5] This is a process diagram for separating foreign matter from a mixture. [Figure 6] This is a process diagram for separating foreign matter from a mixture. [Figure 7] This is a schematic diagram showing the arrangement of magnets in the first alternating magnetic field application unit, as per a separate example. [Modes for carrying out the invention]

[0010] An embodiment of this disclosure is described below. This disclosure is not limited to these examples and includes all modifications in the sense and scope equivalent to the claims. For illustrative purposes, the drawings may exaggerate or simplify some parts of the configuration, and the dimensional proportions of the parts may differ from those of the actual components.

[0011] (Separator 1) As shown in Figure 1, the separation device 1 comprises a transport unit 4 for transporting a mixture 3 mainly composed of material 2, a first alternating magnetic field application unit 6 for lifting non-magnetic material 5 contained in the mixture 3 transported by the transport unit 4 using a magnetic field, and a second alternating magnetic field application unit 8 for separating the non-magnetic material 5 and magnetic material 7 contained in the mixture 3 using a magnetic field. The material 2 is preferably, for example, an active material (negative electrode active material) used in the electrode plates of a battery. The negative electrode active material is preferably, for example, graphite. Examples of non-magnetic material 5 include stainless steel, aluminum, and copper. Examples of magnetic material 7 include iron.

[0012] (Conveying section 4) As shown in Figure 1, the conveying unit 4 is a belt conveyor 11 that carries the mixture 3 on the conveying belt 10 in the conveying direction (direction of arrow A1 in Figure 1) from upstream to downstream. In this case, the conveying unit 4 has a pair of first pulleys 12 and second pulleys 13 that tension the conveying belt 10. The conveying unit 4 drives the conveying belt 10 by rotating the first pulley 12 and the second pulley 13 in the same direction using an actuator (not shown), thereby conveying the mixture 3 on the conveying belt 10.

[0013] (First alternating magnetic field application unit 6) As shown in Figures 1 and 2, the first alternating magnetic field application unit 6 has a plurality of magnetic field generating units 15 arranged such that the magnetic poles alternately switch along the conveying direction of the mixture 3 (direction of arrow A1 in Figure 1). In this example, the magnetic field generating units 15 are preferably magnets 16 that generate a magnetic field in a direction perpendicular to the conveying direction of the conveying unit 4 (direction of arrow A1 in Figure 1). As shown in Figure 2, each of the magnets 16 is formed in a rectangular parallelepiped shape, for example, with one side magnetized as the north pole and the other as the south pole in the thickness direction. The plurality of magnets 16 are arranged with their front and back sides reversed along the conveying direction of the mixture 3 so that the north poles and south poles are alternately located along the conveying direction of the mixture 3.

[0014] As shown in Figure 1, the magnetic field generating unit 15 is positioned on the back surface of the conveyor belt 10 on which the mixture 3 is placed. As a result, the first alternating magnetic field applying unit 6 applies an alternating magnetic field to the mixture 3 placed on the conveyor belt 10 from the back surface of the conveyor belt 10 in order to lift the non-magnetic material 5. The first alternating magnetic field applying unit 6 only needs to be capable of generating a magnetic field sufficient to move the non-magnetic material 5 upwards within the mixture 3. Since the multiple magnetic field generating units 15 of the first alternating magnetic field applying unit 6 are arranged in the conveying direction of the mixture 3, there is sufficient distance to apply an alternating magnetic field to the conveyed non-magnetic material 5 for a long period of time.

[0015] (Magnetic flux density B of the first alternating magnetic field application unit 6) As shown in FIG. 3, the magnetic flux density B required to lift the non-magnetic material 5 inside the mixture 3 is calculated using the Lorentz force calculation formula and the eddy current calculation formula. The force F generated in the non-magnetic material 5 can be obtained by the formula "F = I × L × B", where the eddy current flowing through the non-magnetic material 5 is "I" and the magnetic field length (magnet length) is "L". Also, the eddy current "I" can be obtained by the formula "I = v × B × d / q", where the conveying speed of the non-magnetic material 5 is "v", the diameter of the non-magnetic material 5 is "d", and the resistivity of the non-magnetic material 5 is "q".

[0016] Therefore, the magnetic flux density B required to lift the non-magnetic material 5 inside the mixture 3 is obtained by the formula "√(F × q / (v × d × L))". Thus, the magnetic flux density B generated in the first alternating magnetic field applying section 6 (magnet 16) can be calculated from the above formula.

[0017] (Second alternating magnetic field applying section 8) As shown in FIG. 1, the second alternating magnetic field applying section 8 has a magnet pulley 18 as a second pulley 13 in which N poles and S poles are alternately arranged in the rotation direction. The magnet pulley 18 has two magnetic pole pairs of N poles and S poles in the rotation direction of the magnet pulley 18. The magnet pulley 18 is formed, for example, to have a larger diameter than the diameter of the first pulley 12. The magnet pulley 18 is arranged such that its rotation axis is positioned below the rotation axis of the first pulley 12 so that the surface of the conveying belt 10 on which the mixture 3 is placed becomes horizontal.

[0018] The second alternating magnetic field applying section 8 has a magnet roller 19 that applies an alternating magnetic field to the mixture 3 in cooperation with the magnet pulley 18. The magnet roller 19 is rotatably arranged at a position facing the magnet pulley 18, and in cooperation with the magnet pulley 18, applies an alternating magnetic field stronger than that of the first alternating magnetic field applying section 6 to the mixture 3. The magnet roller 19 has two magnetic pole pairs of N poles and S poles in the rotation direction of the magnet roller 19. The magnet roller 19 rotates about its rotation axis in the direction opposite to the rotation direction of the magnet pulley 18 (direction R2 in FIG. 1) and such that the magnetic poles opposite to those of the magnet pulley 18 face each other.

[0019] The second alternating magnetic field generating unit 8 generates a magnetic field using the magnetic pulley 18 and magnetic roller 19, thereby generating a strong alternating magnetic field at the end of the conveying path of the conveyor belt 10. As a result, the second alternating magnetic field generating unit 8 applies a stronger alternating magnetic field to the mixture 3 than the first alternating magnetic field generating unit 6 at the end of conveying by the conveying unit 4, causing the non-magnetic material 5 that has been lifted inside the mixture 3 to fly.

[0020] Furthermore, the magnetic pulley 18 and magnetic roller 19 can attract the magnetic material 7 contained in the mixture 3 by their own magnetic force. Therefore, when the mixture 3 is transported on the conveyor belt 10 and reaches the end of the transport path, the second alternating magnetic field applying unit 8 attracts the magnetic material 7 inside the mixture 3 with the magnetic force that generates the alternating magnetic field, thereby separating the magnetic material 7 from the mixture 3.

[0021] (Scraping section 21) As shown in Figure 1, the separation device 1 includes a scraping section 21 that scrapes off magnetic material 7 attracted to the second alternating magnetic field applying section 8 from the second alternating magnetic field applying section 8. In this example, the scraping section 21 has a first scraping section 21a that scrapes off magnetic material 7 attracted to the magnetic pulley 18 from the magnetic pulley 18, and a second scraping section 21b that scrapes off magnetic material 7 attracted to the magnetic roller 19 from the magnetic roller 19. The scraping section 21 can be configured in ways such as scraping off magnetic material 7 with the tip of a blade or scraping off magnetic material with a rotating roller member.

[0022] (Housing of material 2, non-magnetic material 5, and magnetic material 7) As shown in Figure 1, the separation device 1 includes a first tray 22 for containing the non-magnetic material 5 separated from the mixture 3, a second tray 23 for containing the magnetic material 7 scraped off from the magnetic pulley 18, and a third tray 24 for containing the magnetic material 7 scraped off from the magnetic roller 19. The first tray 22 is positioned at the destination of the non-magnetic material 5 that has been propelled by the alternating magnetic field of the second alternating magnetic field application unit 8. The second tray 23 is positioned below the first scraping unit 21a. The third tray 24 is positioned adjacent to the second scraping unit 21b.

[0023] (Effect of the embodiment) Next, the operation of the separation device 1 and the separation method of this embodiment will be described. (Step of lifting the non-magnetic material 5 inside mixture 3) As shown in Figure 4, when removing foreign matter from the mixture 3, the supply of the mixture 3 is started upstream of the conveyor belt 10, which rotates in the forward direction (direction of arrow R1 in Figure 4). In this example, the main component of the mixture 3 is graphite, which is used as the negative electrode active material for secondary batteries. The materials removed from the graphite by the separation device 1 include, for example, non-magnetic materials 5 such as stainless steel, aluminum, and copper, and magnetic materials 7 such as iron.

[0024] As shown in Figure 5, as the mixture 3 is carried along by the conveyor belt 10, it is positioned above the first alternating magnetic field application unit 6. At this time, the mixture 3 is subjected to an alternating magnetic field by a magnetic field generating unit 15 (in this example, a magnet 16) which is arranged so that its magnetic poles alternately switch along the conveying direction of the mixture 3, in order to lift the non-magnetic material 5 inside the mixture 3. This alternating magnetic field only needs to be a weak magnetic field that can move the non-magnetic material 5 upwards.

[0025] The non-magnetic material 5 in the mixture 3 experiences a force F in an oblique upward direction in the transport direction due to the magnetic field of magnetic flux density B applied from the first alternating magnetic field application unit 6. The non-magnetic material 5 moves upward due to this force F, and is lifted up inside the mixture 3. In this example, since multiple magnets 16 are arranged in the transport direction of the mixture 3, it is possible to apply an alternating magnetic field to the non-magnetic material 5 for a long time. Therefore, it becomes less likely for any non-magnetic material 5 to escape being lifted inside the mixture 3. Some of the magnetic material 7 inside the mixture 3 is attracted to the first alternating magnetic field application unit 6.

[0026] (Step to separate non-magnetic material 5 and magnetic material 7) As shown in Figure 6, when the mixture 3 is located at the end of the transport path, a strong magnetic field is applied to each component of the mixture 3 by the second alternating magnetic field application unit 8. At this time, the non-magnetic material 5, which is being lifted inside the mixture 3, is propelled toward the first tray 22 by the strong magnetic field applied from the second alternating magnetic field application unit 8. In particular, in this example, since the non-magnetic material 5 is being lifted inside the mixture 3 and is ready to fly, it is unlikely that any of the non-magnetic material 5 will escape when the alternating magnetic field is applied from the second alternating magnetic field application unit 8. The propelled non-magnetic material 5 is then collected in the first tray 22. In this way, the non-magnetic material 5 is separated from the mixture 3.

[0027] When the magnetic material 7 contained in the mixture 3 reaches the end of the transport path, it is attracted by magnetic force to the magnetic pulley 18 and magnetic roller 19 of the second alternating magnetic field application unit 8. The magnetic material 7 attracted to the magnetic pulley 18 rotates with the magnetic pulley 18 and is sent to the first scraping unit 21a. When the magnetic material 7 attracted to the magnetic pulley 18 reaches the first scraping unit 21a, it is separated from the magnetic pulley 18 at the first scraping unit 21a and placed in the second tray 23.

[0028] The magnetic material 7 attracted to the magnetic roller 19 rotates with the magnetic roller 19 and is sent to the second scraping section 21b. When the magnetic material 7 that has been attracted to the magnetic roller 19 reaches the second scraping section 21b, it is separated from the magnetic roller 19 at the second scraping section 21b and placed in the third tray 24.

[0029] In this way, the non-magnetic material 5 and magnetic material 7 are removed from the mixture 3 sent to the end of the transport path, leaving only the material 2. The remaining material 2 then falls naturally downward (diagonally downward) as the transport belt 10 rotates, and is collected in a predetermined tray member (not shown) placed at the drop point. As a result, the non-magnetic material 5 and magnetic material 7 contained in the mixture 3 are removed, and only the remaining material 2 is recovered.

[0030] (Effects of the embodiment) According to the separation device 1 and separation method of this embodiment, the following effects can be obtained.

[0031] (1) The separation device 1 separates the non-magnetic material 5 and magnetic material 7 contained in the mixture 3 from the mixture 3 and extracts the material 2 by applying an alternating magnetic field to the mixture 3 during the process of conveying the mixture 3, which is mainly composed of material 2, by the conveying unit 4. The first alternating magnetic field applying unit 6 provided in the separation device 1 lifts the non-magnetic material 5 inside the mixture 3 by applying an alternating magnetic field to the mixture 3 while the mixture 3 is being conveyed by the conveying unit 4. The second alternating magnetic field applying unit 8 provided in the separation device 1 applies a stronger alternating magnetic field to the mixture 3 than the first alternating magnetic field applying unit 6 at the end of the conveying by the conveying unit 4, causing the non-magnetic material 5 lifted inside the mixture 3 to fly and attracting the magnetic material 7 with the magnetic force of the alternating magnetic field, thereby separating the non-magnetic material 5 and magnetic material 7 from the mixture 3. The first alternating magnetic field applying unit 6 has a plurality of magnetic field generating units 15 arranged so that the magnetic poles alternately switch along the conveying direction of the mixture 3.

[0032] In this configuration, an alternating magnetic field is applied to the mixture 3, which mainly consists of material 2, from the first alternating magnetic field application unit 6 during transport, causing the non-magnetic material 5 to be lifted from within the mixture 3. This makes it easier to detach the non-magnetic material 5 from the mixture 3 when the alternating magnetic field of the second alternating magnetic field application unit 8 is applied to the mixture 3 at the end of the transport path. In particular, since multiple magnetic field generating units 15 are arranged in the transport direction of the mixture 3 as the first alternating magnetic field application unit 6, it is possible to apply an alternating magnetic field to the non-magnetic material 5 for a long time. Therefore, it is less likely that the non-magnetic material 5 will be left behind, and as a result, it is possible to detach the non-magnetic material 5 more reliably. Thus, this contributes to improving the recovery rate of the non-magnetic material 5.

[0033] Furthermore, when the magnetic material 7 inside the mixture 3 reaches the end of the transport path, it is attracted to the strong magnetic field of the second alternating magnetic field applying unit 8, thereby separating the magnetic material 7 from the mixture 3. Therefore, by using the second alternating magnetic field applying unit 8, which generates a strong magnetic field, it becomes possible to more reliably separate the magnetic material 7 from the mixture 3. As a result, the recovery rate of non-magnetic material 5 and magnetic material 7, which are foreign matter inside the mixture 3, can be improved.

[0034] (2) The magnetic field generating unit 15 is a magnet 16 that generates a magnetic field in a direction perpendicular to the transport direction of the transport unit 4. With this configuration, the magnetic field generating unit 15 can be made into a simple configuration using a magnet 16.

[0035] (3) The conveying section 4 is a belt conveyor 11 that carries the mixture 3 on the conveyor belt 10 from upstream to downstream. The first alternating magnetic field application section 6 applies an alternating magnetic field to the mixture 3 placed on the conveyor belt 10 from the underside of the conveyor belt 10 in order to lift the non-magnetic material 5. The second alternating magnetic field application section 8 has a magnetic pulley 18 that drives the conveyor belt 10 by rotation and whose magnetic poles alternately switch along the direction of rotation. With this configuration, the pulley, which is an element of the belt conveyor 11, is the magnetic pulley 18, and this magnetic pulley 18 is used as the second alternating magnetic field application section 8. As a result, the components of the belt conveyor 11 have both pulley function and alternating magnetic field application function, so it is possible to reduce the number of parts compared to when these functions are provided as separate parts. Thus, it contributes to simplifying the configuration of the separation device 1.

[0036] (4) The second alternating magnetic field applying unit 8 is rotatably positioned opposite the magnetic pulley 18 and has a magnetic roller 19 that cooperates with the magnetic pulley 18 to apply a stronger alternating magnetic field to the mixture 3 than the first alternating magnetic field applying unit 6. With this configuration, at the end of the conveying path of the mixture 3, the magnetic material 7 is attracted by both the magnetic pulley 18 and the magnetic roller 19, thereby separating the magnetic material 7 from the mixture 3. As a result, the magnetic material 7 can be separated from the mixture 3 more reliably. Thus, this contributes to further improving the recovery rate of the magnetic material 7.

[0037] (5) The separation device 1 is equipped with a scraping unit 21 that scrapes off the magnetic material 7 attracted to the second alternating magnetic field applying unit 8 from the second alternating magnetic field applying unit 8. With this configuration, the magnetic material 7 attracted by the second alternating magnetic field applying unit 8 is scraped off by the scraping unit 21 and stored in the second tray 23 and the third tray 24. Thus, the magnetic material 7 separated from the mixture 3 can be stored together in one place.

[0038] (Other embodiments) This embodiment can be implemented with the following modifications. This embodiment and the following modifications can be combined with each other to the extent that they do not contradict each other technically.

[0039] As shown in Figure 7, the first alternating magnetic field applying unit 6 and the conveyor belt 10 may be inclined so that the distance between them decreases toward the downstream side in the conveying direction of the mixture 3. In the example in Figure 7, the conveyor belt 10 is inclined so that it approaches the first alternating magnetic field applying unit 6 toward the downstream side. In this case, when the non-magnetic material 5 is lifted by the alternating magnetic field of the first alternating magnetic field applying unit 6, even if the non-magnetic material 5 moves in the conveying direction, the distance away from the first alternating magnetic field applying unit 6 does not increase. Therefore, it becomes easier to maintain the lifted state of the non-magnetic material 5, which contributes to ensuring the flight capability of the non-magnetic material 5 and, consequently, to improving the recovery rate of the non-magnetic material 5.

[0040] The magnetic field generating unit 15 of the first alternating magnetic field generating unit 6 is not limited to a magnet 16, but may also be, for example, a coil that generates a magnetic field by electromagnetic induction. • The lifting of the non-magnetic material 5 refers, for example, to the movement of the non-magnetic material 5 upwards within the mixture 3. Furthermore, the lifting of the non-magnetic material 5 also includes, for example, a state where the non-magnetic material 5 floats above the surface of the conveyor belt 10 within the mixture 3, or a state where the leading edge of the non-magnetic material 5 in the conveying direction points upwards.

[0041] The second alternating magnetic field applying unit 8 may be configured to have only a magnetic pulley 18. In the second alternating magnetic field applying unit 8, the member that propels the non-magnetic material 5 and the member that attracts the magnetic material 7 by magnetic force may be composed of different members.

[0042] The conveying unit 4 is not limited to a belt conveyor 11; any unit capable of conveying the mixture 3 from upstream to downstream is acceptable. • In the case of battery materials, the material to be separated (material 2) is not limited to the negative electrode active material, but may also be the positive electrode active material.

[0043] • Material 2 to be separated may be something other than battery material. This disclosure is described in accordance with the embodiments, but is not limited to the structures of these embodiments and includes various modifications and variations within the equivalence range. This disclosure also includes various combinations and forms, as well as combinations and forms of one, more, or fewer of these elements. [Explanation of symbols]

[0044] 1...Separation device, 2...Material, 3...Mixture, 4...Conveying unit, 5...Non-magnetic material, 6...First alternating magnetic field application unit, 7...Magnetic material, 8...Second alternating magnetic field application unit, 10...Conveyor belt, 11...Belt conveyor, 15...Magnetic field generation unit, 16...Magnet, 18...Magnetic pulley, 19...Magnetic roller, 21...Scraping unit.

Claims

1. A separation device that separates non-magnetic and magnetic substances contained in a mixture by applying an alternating magnetic field to a mixture in the process of conveying a mixture mainly composed of a material by a conveying unit, thereby extracting the material, While the mixture is being transported by the transport unit, a first alternating magnetic field applying unit applies an alternating magnetic field to the mixture to lift the non-magnetic material within the mixture, The system includes a second alternating magnetic field application unit that, at the end of transport by the transport unit, applies an alternating magnetic field stronger than that of the first alternating magnetic field application unit to the mixture, thereby causing the non-magnetic material lifted within the mixture to fly, and attracting the magnetic material with the magnetic force of the alternating magnetic field, thereby separating the non-magnetic material and the magnetic material from the mixture. The first alternating magnetic field application unit is a separation device having a plurality of magnetic field generating units arranged such that the magnetic poles alternately switch along the conveying direction of the mixture.

2. The separation device according to claim 1, wherein the magnetic field generating unit is a magnet that generates a magnetic field in a direction perpendicular to the transport direction of the transport unit.

3. The conveying section is a belt conveyor that carries the mixture on a conveyor belt from upstream to downstream. The first alternating magnetic field applying unit applies an alternating magnetic field to the mixture placed on the conveyor belt from the back surface of the conveyor belt in order to lift the non-magnetic material. The separation device according to claim 1, wherein the second alternating magnetic field applying unit has a magnetic pulley that drives the conveyor belt by rotation and whose magnetic poles alternately switch along the direction of rotation.

4. The separation apparatus according to claim 3, wherein the second alternating magnetic field applying unit has a magnetic roller that is rotatably arranged in a position opposite to the magnetic pulley, and cooperates with the magnetic pulley to apply a stronger alternating magnetic field to the mixture than that of the first alternating magnetic field applying unit.

5. The separation device according to claim 1, further comprising a scraping unit for scraping off the magnetic material attracted to the second alternating magnetic field applying unit from the second alternating magnetic field applying unit.

6. A separation method for separating non-magnetic and magnetic substances contained in a mixture by applying an alternating magnetic field to a mixture in the process of conveying the mixture, the material being extracted from the mixture, wherein the mixture is conveyed by a conveying unit, and the alternating magnetic field is applied to the mixture. While the mixture is being transported by the transport unit, a first alternating magnetic field applying unit, which has a plurality of magnetic field generating units arranged so that the magnetic poles alternately switch along the transport direction of the mixture, applies an alternating magnetic field to the mixture, thereby lifting the non-magnetic material from within the mixture. A separation method comprising the step of separating the non-magnetic material and the magnetic material from the mixture by applying an alternating magnetic field stronger than that of the first alternating magnetic field application unit to the mixture from the second alternating magnetic field application unit at the end of the conveying by the conveying unit, thereby causing the non-magnetic material lifted within the mixture to fly and attracting the magnetic material with the magnetic force of the alternating magnetic field.

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