Particle separation method and particle separation device

Abstract

To provide a particle separation method capable of separating even small particles with a simple mechanism.SOLUTION: A particle separation method according to the present invention includes the steps of: accommodating mixed particles containing first particles and second particles having a higher density than the first particles in a container; applying vertical vibration to the container such that the vibration intensity is 1 or higher, thereby moving the first particles vertically downward relative to the second particles within the container; and taking out the first particles or the second particles after movement within the container.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a method and an apparatus for separating particles. [Background technology]

[0002] For various purposes, such as sorting resources, sorting waste, and removing foreign matter, specific particles are separated from mixed particles (powders) by utilizing differences in density. Particle separation methods that utilize such density differences can be broadly divided into wet separation, which uses water, and dry separation, which does not use water. Wet separation is widely used, mainly in the field of resource recycling, and devices such as thin-flow separators (see Non-Patent Document 1) and jig separators (see Non-Patent Document 2), which are based on the phenomenon of floating and sinking in water due to differences in specific gravity, have been put to practical use. For dry separation, separation technologies that utilize air flow, such as air table separators, fluidized bed separators, and pneumatic separators, have been proposed (see Non-Patent Document 3).

[0003] Dry separation has advantages such as its use in areas with scarce water resources and its application to materials that are not suitable for wetting. However, in dry separation, the separation efficiency is determined by the complex interactions of gravity, inertial force, fluid force, and other factors, compared to simple wet separation that uses only buoyancy. For this reason, dry separation is not very versatile and is only used for small-scale separation of specific materials. Furthermore, it is known that the fluidity of powders in air deteriorates significantly as the particle size decreases. Therefore, small particles (e.g., particles with a particle size of 150 μm or less) are difficult to separate by dry separation and have often been separated by wet separation (Non-Patent Document 4). [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] Holland-Batt, AB, Hunter, JL and Turner, JH, “The separation of coal fines using flowing-film gravity concentration”, Powder Technology, Vol. 40, pp. 129-145. [Non-patent document 2] Mukherjee, AK, Bhattacharjee, D. and Mishra, BK, “Role of water velocity for efficient jigging of iron ore”, Minerals Engineering, Vol. 19, pp. 952-959. [Non-patent document 3] Zhou, C., Xibo, L., Zhao, Y., Yang, X., Li, Y., Dong, L., Duan, C. and Rao, Z., “Recent progress and potential challenges in coal upgrading via gravity dry separation technologies”, Fuel, Vol. 305, 121430. [Non-patent document 4] Geldart, D., “Types of gas fluidization, Powder Technology”, Vol. 7, pp. 285-292. Summary of the Invention [Problem to be solved by the invention]

[0005] Conventional dry separation requires complex mechanisms, such as a combination of vibration and airflow, and as mentioned above, it is difficult to separate small particles using conventional dry separation.

[0006] An object of the present invention is to provide a particle separation method and particle separation device that can separate even small particles (for example, particles with a particle diameter of 150 μm or less) using a simple mechanism. [Means for solving the problem]

[0007] The present invention relates to the following particle separation method and particle separation device. [1] A method for separating particles, comprising: placing a mixed particle containing first particles and second particles having a higher density than the first particles in a container; applying vertical vibration to the container so that the vibration intensity is 1 or greater, thereby moving the first particles vertically below the second particles within the container; and removing the first particles or the second particles after moving within the container. [2] The particle separation method according to [1], wherein in the step of vibrating the container, vibration is applied to the container so as to satisfy the following formula (1):

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[0008] According to the present invention, it is possible to provide a particle separation method and particle separation device that can separate even small particles using a simple mechanism. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a front view of a particle separation device according to an embodiment of the present invention. [Figure 2] Fig. 2A is a diagram showing the state of the mixed particles before vibration is applied, and Fig. 2B is a diagram showing the state of the mixed particles after vibration is applied. [Figure 3] 3A to 3C are diagrams for explaining the mechanism by which particles with different densities are separated from each other. [Figure 4] Figure 4A shows particles in a state of reverse segregation, and Figure 4B shows particles in a state of sandwich segregation. [Figure 5] Figure 5A is a photograph showing the state of the mixed particles before vibration is applied, and Figure 5B is a photograph showing the state of the mixed particles after vibration is applied. [Figure 6] Figure 6 is a high-speed photograph showing glass particles intermittently ejected from the outlet. [Figure 7] Figure 7A is a photograph showing particles in a reverse segregation state, and Figure 7B is a photograph showing particles in a sandwich segregation state. [Figure 8] Fig. 8A is a graph showing the relationship between the frequency f, vibration intensity Γ, and segregation state when the height L of the mixed particle layer is 50 mm. Fig. 8B is a graph showing the relationship between the frequency f, vibration intensity Γ, and segregation state when the height L of the mixed particle layer is 70 mm. Fig. 8C is a graph showing the relationship between the frequency f, vibration intensity Γ, and segregation state when the height L of the mixed particle layer is 80 mm. [Figure 9] FIG. 9 is a photograph showing the state of the mixed particles after vibration has been applied. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to these. In this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​written before and after "to" as the lower and upper limits.

[0011] (Configuration of separation device) Fig. 1 is a front view of a particle separation device 100 (hereinafter also simply referred to as "separation device 100") according to one embodiment of the present invention. As shown in Fig. 1, separation device 100 according to this embodiment has a container 110 and a vibration unit 120. In Fig. 1, the internal space (accommodation unit 111) of container 110 and a part of a screw 114 for fixing container 110 to vibration unit 120 are indicated by dashed lines.

[0012] The container 110 has a storage section 111 for storing mixed particles 130 containing particles to be separated and extracted (hereinafter also referred to as "target particles"). A specific position on the sidewall of the container 110 is provided with an extraction port 112 for extracting the target particles. The shape of the container 110 is not particularly limited, but it is preferable that the container 110 has a shape (a cylindrical shape with a bottom) whose horizontal cross section is the same even at different heights. The horizontal cross section shape is not particularly limited and may be, for example, a circle, a square, a triangle, or the like. The size of the container 110 is not particularly limited and can be appropriately selected depending on the application, etc. The top of the container 110 may be open or may be closed with a lid (not shown). For example, the opening of the container 110 may be open to the side rather than upward. In the example shown in FIG. 1, the container 110 is a cylindrical container with a bottom that is open upward. The material of the container 110 is also not particularly limited and can be appropriately selected depending on the application, etc. Examples of materials for the container 110 include metals such as stainless steel and aluminum, resins such as acrylic resin, and glass.

[0013] The outlet 112 is a passage located at a specific position on the sidewall of the container 110, connecting the storage section 111 inside the container 110 to the outside. The outlet 112 is located to match the position of the target particles after the container 110 is vibrated and moved. For example, if the lowest-density particles among the mixed particles 130 are to be extracted, the outlet 112 is located at the bottom of the container 110. On the other hand, if the highest-density particles among the mixed particles 130 are to be extracted, the outlet 112 is located in the middle or upper part of the container 110. The number of outlets 112 is not particularly limited and may be one or two or more. Multiple outlets 112 may be located at the same height or at different heights on the container 110. The shape and size of the outlets 112 are not particularly limited and can be selected appropriately depending on the application, etc. In the example shown in FIG. 1, one cylindrical outlet 112 is located at the bottom of the container 110. When target particles are not being taken out, the outlet 112 is preferably closed with a rubber plug (not shown) or the like.

[0014] 1, a flange 113 having a plurality of through holes is provided at the bottom of the container 110. In this embodiment, the container 110 is fixed to the vibration table 121 by threading screws 114 from above the flange 113 through the through holes into the vibration table 121 of the vibration unit 120.

[0015] The vibration unit 120 applies vertical vibration to the container 110 so that the vibration intensity is 1 or more. The configuration of the vibration unit 120 is not particularly limited as long as it can perform the above-mentioned function. For example, the vibration unit 120 may have a vibration table 121, and the container 110 may be fixed to the vibration table 121. The vibration unit 120 may be a commercially available vibrator. The vibration unit 120 may be connected to a power amplifier, a function generator, or the like (not shown).

[0016] (Method of separating particles) Next, a method for separating particles using the above-described separation device 100 will be described.

[0017] For example, the target particles can be separated from the mixed particles by performing the following steps: (1) a step (supply step) of storing mixed particles 130 containing the target particles in a container 110, (2) a step (separation step) of applying vertical vibration to the container 110 so that the vibration intensity is 1 or more to move the particles within the container 110, and (3) a step (removal step) of removing the target particles after they have moved within the container 110. The steps (1) to (3) above may be performed in order or simultaneously in parallel.

[0018] Each step will be described below with reference to Figures 2A and 2B. For ease of explanation, Figures 2A and 2B also show particles in container 110.

[0019] (1) Supply process In the supplying step, as shown in FIG. 2A, mixed particles 130 containing target particles are placed in a container 110. The mixed particles 130 contain target particles and other particles having a density different from that of the target particles. In this specification, "density" refers to true density. The type of other particles may be one type, or two or more types.

[0020] The types of target particles and other particles are not particularly limited. The target particles and other particles may be various powders, such as artificial powders and natural powders. Examples of the target particles and other particles include metal particles, resin particles, sand, ceramic particles, cement particles, coal particles, incineration ash, and powdered chemicals. The particle diameters of the target particles and other particles are not particularly limited, but from the viewpoint of balancing separation efficiency and extraction (ejection) efficiency, they are preferably approximately 50 μm to 2 mm, more preferably approximately 100 μm to 1 mm, and particularly preferably approximately 100 to 500 μm. The particle diameters of the target particles and other particles may be the same or different. In this description, the mixed particles 130 are described as including first particles 131 having a relatively low density and second particles 132 having a relatively high density. The particles to be separated and extracted (target particles) may be either the first particles 131 or the second particles 132. 2A and 2B, the particle of interest is a first particle 131. If the particle of interest is a second particle 132, the outlet 112 is positioned higher on the sidewall of the container 110.

[0021] The mixed particles 130 may be supplied to the container 110 only once, multiple times, or continuously. For example, the mixed particles 130 may be supplied continuously to the container 110 while the separation step and extraction step described below are simultaneously performed in parallel.

[0022] (2) Separation process In the separation process, vertical vibration is applied to the container 110 so that the vibration intensity Γ is 1 or more, and the first particles 131, which have a relatively low density, are moved vertically downward relative to the second particles 132, which have a relatively high density, within the container 110. Here, the vibration intensity Γ means the ratio of the maximum acceleration to the gravitational acceleration expressed by the following equation (3). In equation (3), g is the gravitational acceleration (m / s 2 ), where f is the frequency (Hz) and a is the amplitude (m).

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[0023] When vertical vibrations are applied to the container 110 such that the vibration intensity is 1 or greater, the mixed particles 130 (mixed particle layer) in the container 110 bounce off the bottom of the container 110, then fall freely and repeatedly collide with the bottom. As a result, particles with relatively low density (e.g., first particle 131) move relatively lower within the particle group (mixed particle layer), while particles with relatively high density (e.g., second particle 132) move relatively higher within the particle group. In other words, particles with lower density move lower, and particles with higher density move higher. As a result, the particles contained in the mixed particles 130 are separated according to their densities. In the example shown in FIG. 2B, the first particle 131, which has a relatively low density, moves to the bottom of the container 110, and the second particle 132, which has a relatively low density, moves to the center of the container 110 (between the bottom and the top).

[0024] Typically, when vibration is applied to a container containing mixed particles 130, "segregation" often occurs, in which particles with a relatively high density move downward and particles with a relatively low density move upward. However, in this embodiment, by applying vertical vibration to container 110 containing mixed particles 130 so that the vibration intensity is 1 or greater, "reverse segregation" can occur, in which first particles 131 (e.g., glass particles) with a relatively low density move downward and second particles (e.g., iron particles) with a relatively high density move upward, as shown in FIG. 2B. The inventors measured and analyzed the pressure inside container 110 and estimated the mechanism by which reverse segregation occurs as follows. However, the mechanism by which reverse segregation occurs is not limited to this.

[0025] 3A to 3C are diagrams illustrating the mechanism by which reverse segregation occurs when particles with different densities in mixed particles 130 are separated from one another. When vertical vibrations are applied to container 110 containing mixed particles 130 with a vibration intensity of 1 or more, the cycles shown in FIGS. 3A, 3B, and 3C are repeated within container 110.

[0026] When a vertical vibration is applied to a container 110 containing mixed particles 130 such that the vibration intensity is 1 or greater, the mixed particles 130 (mixed particle layer) in the container 110 jump away from the bottom surface of the container 110. That is, the state transitions from FIG. 3C to FIG. 3A. As shown in FIG. 3A, when an upward force is applied to the container 110 from the vibration unit 120 (vibration table 121) (the black arrow pointing up on the bottom of FIG. 3A), the mixed particles 130 in the container 110 also jump upward (the black arrow pointing up on the top of FIG. 3A). This creates a space between the mixed particles 130 and the bottom surface of the container 110, and this space has a negative pressure relative to the ambient air pressure (outside the container 110). Therefore, air located above the mixed particles 130 moves toward this space via the mixed particles 130 (the white arrow pointing down in FIG. 3A). This fluid (air) flow affects each particle contained in the mixed particles 130. That is, a force (fluid force) due to the pressure difference acts on each particle. On the other hand, as shown in FIG. 3B, when the mixed particles 130 fall toward the bottom of the container 110, this space becomes positive pressure relative to the ambient (outside the container 110) air pressure. At this time, the flow of the fluid (air) also affects each particle contained in the mixed particles 130. When a fluid force acts on each particle in this way, particles with relatively low density (e.g., first particle 131) are more susceptible to the fluid force than particles with relatively high density (e.g., second particle 132) due to the difference in inertia. That is, particles with relatively low density (e.g., first particle 131) move farther than particles with relatively high density (e.g., second particle 132). Here, the relative motion of each particle is greatest when the mixed particles 130 jump, when they are easily movable, i.e., at the moment when a downward fluid force acts (see FIG. 3A), and therefore, particles with relatively low density, which have small inertia, accumulate at the bottom. As a result, reverse segregation occurs in which the first particles 131 (for example, glass particles) having a relatively low density move downward, and the second particles 132 (for example, iron particles) having a relatively high density move upward.

[0027] The vibration intensity Γ of the vibration applied to the container 110 is not particularly limited as long as it is equal to or greater than 1. From the viewpoint of generating reverse segregation in a short time, the vibration intensity Γ is preferably greater than 1, more preferably equal to or greater than 2, and more preferably equal to or greater than 3.

[0028] As described above, applying vertical vibration to the container 110 containing the mixed particles 130 so that the vibration intensity is 1 or greater causes "reverse segregation," in which the relatively low-density first particles 131 move downward and the relatively high-density second particles 132 move upward, as shown in FIG. 4A (FIG. 2B). However, depending on the vibration conditions, "sandwich segregation," in which not only some of the relatively low-density first particles 131 move downward and the relatively high-density second particles 132 move upward, but also other parts of the relatively low-density first particles 131 move further above the second particles 132, as shown in FIG. 4B, may occur. Even when sandwich segregation occurs, the first particles 131 and / or the second particles 132 can be extracted if the outlet 112 is appropriately positioned. However, it is easier to extract the first particles 131 efficiently by causing reverse segregation than by sandwich segregation.

[0029] 4A is desired instead of the sandwich segregation shown in Fig. 4B, it is preferable to apply vertical vibration to the container 110 containing the mixed particles 130 so as to satisfy the following formula (4) in addition to setting the vibration intensity to 1 or more. For example, by lowering the vibration frequency f or reducing the amount of the mixed particles 130 so as to satisfy formula (4), it is possible to cause the reverse segregation.

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[0030] The present inventors conducted an analysis focusing on the movement of fluid (air) in a mixed particle layer and found that reverse segregation can be generated by setting the dimensionless number K (Konno number) expressed by the following equation (6) to 1 or less.

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[0031] When K in the above formula (6) exceeds 1, this means that a new pressure change occurs at the bottom of the container 110 before the pressure change that occurred at the bottom of the container 110 is transmitted to the upper part of the mixed particle 130. In such a case, negative pressure is generated not only at the lower part but also at the upper part of the mixed particle 130 when the mixed particle 130 jumps, and the relatively low-density particles (first particles 131) move not only downward but also upward, which is thought to result in sandwich segregation. On the other hand, when K in the above formula (6) is 1 or less, this means that a new pressure change occurs at the bottom of the container 110 after the pressure change that occurred at the bottom of the container 110 is transmitted to the upper part of the mixed particle 130. In such a case, negative pressure is generated only at the lower part of the mixed particle 130 when the mixed particle 130 jumps, and the relatively low-density particles (first particles 131) move only downward, which is thought to result in reverse segregation.

[0032] By incorporating equations (7) and (8) into equation (6), K is expressed as in equation (9) below. Therefore, equation (4) above means that K is 1 or less.

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[0033] (3) Removal process In the removal step, the first particles 131 or the second particles 132 are removed after being moved inside the container 110 by vibration. The particles to be removed (target particles) are not particularly limited, and may be the first particles 131 or the second particles 132. Alternatively, the first particles 131 and the second particles 132 may be removed separately.

[0034] The method for extracting the first particles 131 or the second particles 132 separated by moving within the container 110 is not particularly limited. For example, the first particles 131 or the second particles 132 may be extracted by suction through the outlet 112. Alternatively, the first particles 131 or the second particles 132 may be ejected from the outlet 112 by applying pressure from above to the inside of the container 110. However, in this embodiment, it is preferable to eject the first particles 131 or the second particles 132 from the outlet 112 by applying vertical vibration to the container 110 with the outlet 112 open so that the vibration intensity is 1 or greater. In the example shown in FIG. 2B , the pressure at the bottom of the container 110 is increased by applying vertical vibration to the container 110, causing the first particles 131 to be ejected from the outlet 112. At this time, the first particles 131 are ejected intermittently in accordance with the vibration (see Examples). In this way, by ejecting the first particles 131 or the second particles 132 from the outlet 112, the separation process and the extraction process can be carried out simultaneously. At this time, the supply process may also be carried out simultaneously. In this way, continuous particle separation can be achieved, in which the target particles (first particles 131 or second particles 132) are extracted while the mixed particles 130 are being supplied.

[0035] (effect) As described above, the particle separation device and separation method according to the present embodiment can separate even small particles using a simple mechanism, even though it is a dry separation method. For example, the particle separation device and separation method according to the present embodiment can easily separate and extract particles with a particle diameter of 150 μm or less, especially particles with a particle diameter of 100 μm or less.

[0036] In the above description, the case where the mixed particles 130 are surrounded by air has been described, but the fluid surrounding the mixed particles 130 may not be air but may be another fluid (gas).

[0037] The present invention will be described in more detail by the following examples, but the present invention is not limited to these examples. [Example]

[0038] [Experiment 1] A separation device as shown in Figure 1 was prepared. A cylindrical, transparent container with a bottom and an inner diameter of 50 mm was used as the container 110. A metal outlet port 112 with an inner diameter of 4 mm was provided on the side wall of the container, 5 mm above the bottom of the container. A small vibration testing device (m030 / MA1-CE, IMV Corporation) was used as the vibration unit 120. The container was fixed to the vibration table of the vibration testing device.

[0039] The first particles, which have a relatively low density, are glass particles with an average particle diameter of 153 μm (density: 2500 kg / m 3 As the second particles with a relatively high density, iron particles (density: 7450 kg / m) with a particle diameter of 125 to 180 μm (average particle diameter: approximately 150 μm) were prepared. 3 Glass particles and iron particles were mixed in a volume ratio of 1:1 to prepare mixed particles.

[0040] As shown in Figure 5A, a mixed particle was placed in a container with a sealed outlet using a rubber stopper. In Figure 5A, the glass particles appear white, and the iron particles appear black. When vertical vibrations (sine vibration, frequency: 30 Hz) were applied to the container so that the vibration intensity Γ was greater than 1, reverse segregation occurred, as shown in Figure 5B. When vertical vibrations (sine vibration, frequency: 30 Hz) were applied to the container with the rubber stopper removed, the glass particles that had accumulated at the bottom of the container were ejected from the outlet. Analysis of the ejected particles revealed that they contained almost no iron particles and were composed solely of glass particles. Note that Figure 5B shows the state after a certain amount of glass particles had been ejected, so the glass particles appear to be fewer in number than the iron particles.

[0041] Although the glass particles appeared to be ejected continuously, analysis of the ejection using high-speed photography revealed that the glass particles were ejected intermittently in accordance with the vibration of the container, as shown in Figure 6. When mixed particles were poured into the container from above while glass particles were ejecting from the outlet, the glass particles contained in the mixed particles instantly moved to the bottom of the container and ejected from the outlet.

[0042] Furthermore, when a similar experiment was performed in a vacuum state inside the container, no reverse segregation of particles was observed. This indicates that gas (air) is required in the gaps between particles to cause reverse segregation of particles.

[0043] Next, a container containing the above-mentioned mixed particles (glass particles and iron particles mixed at a volume ratio of 3:1) was subjected to vertical vibration at 30 Hz (sine vibration, vibration intensity: 1 or more). As a result, reverse segregation occurred, in which the glass particles (white) accumulated at the bottom of the container and the iron particles (black) accumulated on top of the glass particles, as shown in Figure 7A. On the other hand, when a container containing the same mixed particles was subjected to vertical vibration at 60 Hz (sine vibration, vibration intensity: 1 or more), sandwich segregation occurred, in which some of the glass particles (white) accumulated at the bottom of the container, the iron particles (black) accumulated on top of the glass particles, and the remaining glass particles (white) accumulated on top of the iron particles, as shown in Figure 7B.

[0044] To investigate the conditions under which reverse segregation occurs, we repeatedly conducted experiments in which the mixed particles were subjected to vertical vibration for 3 minutes while changing various conditions (height L of the mixed particle layer in the container, vibration frequency f, and vibration intensity Γ). The vibration intensity Γ was adjusted by changing the amplitude a. The experimental results are shown in Figures 8A-C. Figure 8A is a graph showing the relationship between the vibration frequency f and vibration intensity Γ and the segregation state when the height L of the mixed particle layer was 50 mm. Figure 8B is a graph showing the relationship between the vibration frequency f and vibration intensity Γ and the segregation state when the height L of the mixed particle layer was 70 mm. Figure 8C is a graph showing the relationship between the vibration frequency f and vibration intensity Γ and the segregation state when the height L of the mixed particle layer was 80 mm. In these graphs, triangular points indicate reverse segregation, square points indicate sandwich segregation, and round points indicate that no specific segregation state was achieved within 3 minutes. These graphs also show dashed lines where K (Konno number) expressed by the following equation (10) is 1. In the region to the left of these dashed lines, K≦1. When calculating K, the diffusion coefficient α of the air pressure in the mixed particle layer is set to 0.27 m 2 / s. This diffusion coefficient α is calculated by taking the air pressure p0 in the container in the above equation (5) as 101.3 × 10 3 Pa, air viscosity μ is 1.83 x 10 -5 Pa·s, the average porosity of the mixed particle layer ε is 0.38, and the volume average particle diameter of the mixed particles d p 153×10 -6 It was calculated by setting m.

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[0045] As shown in Figures 8A-C, by adjusting the vibration frequency f and vibration intensity Γ so that K ≦ 1, reverse segregation can be achieved without sandwich segregation, regardless of the height L of the mixed particles in the container. In Figures 8B and 8C, triangular points indicating reverse segregation also exist in the K > 1 region. Under these conditions, reverse segregation occurred after sandwich segregation. On the other hand, in Figures 8A-C, triangular points in the K ≦ 1 region indicate reverse segregation without sandwich segregation. Furthermore, even in the K ≦ 1 region, when the vibration intensity Γ was small, sufficient segregation sometimes did not occur within 3 minutes. However, it is believed that reverse segregation can be achieved by extending the vibration time.

[0046] [Experiment 2] The same separation equipment as in Experiment 1 was prepared. Plastic particles with a particle diameter of 75 to 180 μm (density: 1470 to 1520 kg / m) were used as the first particles with a relatively low density. 3 ) was prepared. Toyoura sand (density: 2650 kg / m) with a particle size of 106 to 300 μm was used as the second particle with a relatively high density. 3 ) was prepared. Plastic particles and Toyoura sand were mixed in a volume ratio of 1:3 to prepare mixed particles.

[0047] The mixed particles were placed in a container with a sealed outlet and a rubber stopper. The height L of the mixed particle layer was 70 mm. Vertical vibration (sine vibration, frequency: 25 Hz) was applied to the container for 15 minutes so that the vibration intensity Γ was greater than 1. As shown in Figure 9, reverse segregation occurred, with the low-density plastic particles (white) accumulating at the bottom of the container and the high-density Toyoura sand (yellow) accumulating on top of the plastic particles. [Industrial Applicability]

[0048] The particle separation method and particle separation device according to the present invention are useful for, for example, recovering useful resources such as precious metals and recovering waste plastics. [Explanation of symbols]

[0049] 100 particle separator 110 Container 111 Storage unit 112 Outlet 113 flange 114 Screw 120 Vibration unit 121 Shaking Table 130 Mixed particles 131 1st particle 132 2nd particle

Claims

1. A step of placing a mixture of particles including first particles and second particles having a higher density than the first particles in a container; applying vertical vibration to the container so that the vibration intensity is 1 or more, thereby moving the first particles vertically below the second particles within the container; removing the first particles or the second particles after they have moved within the container; A method for separating particles, comprising:

2. 2. The particle separation method according to claim 1, wherein in the step of applying vibration to the container, vibration is applied to the container so as to satisfy the following formula (1): [Equation 1] (In Equation (1), f is the frequency (Hz), L is the height (m) of the layer of the mixed particles in the container, and α is the diffusion coefficient (m ２ / s).

3. The particle separation method according to claim 1 , wherein the step of applying vibration to the container and the step of extracting the first particles or the second particles are carried out in parallel.

4. The particle separation method according to claim 1 , wherein the step of placing the mixed particles in a container, the step of applying vibration to the container, and the step of extracting the first particles or the second particles are performed in parallel.

5. 5. The particle separation method according to claim 3, wherein in the step of extracting the first particles or the second particles, the first particles or the second particles are intermittently ejected from an outlet disposed in a side wall of the container.

6. a container for containing a mixture of particles including first particles and second particles having a density higher than that of the first particles; an outlet located in a sidewall of the container; a vibration unit for applying vertical vibration to the container so that the vibration intensity is 1 or more; A particle separation device comprising:

7. The particle separation device according to claim 6 , wherein the vibration unit applies vibration to the container so as to satisfy the following formula (2): [Equation 2] (In equation (2), f is the frequency (Hz), L is the height (m) of the layer of the mixed particles in the container, and α is the diffusion coefficient (m ２ / s).

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