Air table type density separation apparatus and separation method

Abstract

To provide an air table type density separation apparatus and a separation method capable of improving accuracy in separating three or more kinds of particles having small particle diameters into respective kinds.SOLUTION: An air table type density separation apparatus 100 includes: a first bottom plate 21 inclined so as to be lowered toward each of a first direction and a second direction from a charge port of a plurality of separation targets, and at least one baffle plate 6 extending in the second direction on the first bottom plate 21. The first bottom plate 21 has a first hole 214 through which a gas blown out from a back surface 212 toward a front surface 211 passes. A diameter D2 of the first hole 214 in the back surface 212 of the first bottom plate 21 is larger than at least some of the plurality of separation targets. A diameter D1 of the first hole 214 on the front surface 211 of the first bottom plate 21 is larger than the diameter D2 of the first hole 214 on the back face 212 of the first bottom plate 21.SELECTED DRAWING: Figure 2C

Description

[Technical Field]

[0001] The present disclosure relates to an air table type density separation device and separation method for separating particles according to density differences. [Background technology]

[0002] Blast furnace trough refractories, which form the troughs through which molten iron flows during the ironmaking process, are dismantled when they become severely damaged or worn. Dismantling blast furnace trough refractories generates raw materials that contain a mixture of three types of components: slag line (SL) material, metal line (ML) material, and slag material. When blast furnace trough refractories are made from raw materials containing slag material, the quality of the blast furnace trough refractories is unstable. Therefore, raw materials containing slag material are difficult to use as recycled refractory raw materials and are mainly disposed of as industrial waste.

[0003] However, SL material or ML material is a material with great potential as a refractory material. It is desirable to recycle SL material or ML material as a refractory raw material by separating and recovering it in a stable state. The three components of SL material, ML material, and slag material have very similar colors. Therefore, it is difficult to separate the three components of SL material, ML material, and slag material using a color sorting method based on the color of the components.

[0004] A method for separating three types of components, SL material, ML material, and slag material, is known, utilizing the density differences among the components, as disclosed in Patent Document 1. The air table-type density separator disclosed in Patent Document 1 can separate particles of different densities according to their density differences by vibrating a table surface tilted at a predetermined angle in a predetermined direction and blowing air through holes in the table surface to create an airflow. Specifically, low-density particles float due to the airflow and move toward lower positions on the tilted table surface due to reduced friction with the vibrating table surface. On the other hand, high-density particles are less likely to float than low-density particles and experience greater friction with the vibrating table surface than low-density particles, resulting in higher positions on the tilted table surface. Particles of each density can be separated by setting baffles according to the height at which each density particle moves. As a result, the air table-type density separator can separate three or more types of particles according to their density differences.

[0005] Another known separation method is to use a cyclone separator, as disclosed in Patent Document 2. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 7270404 [Patent Document 2] Japanese Unexamined Patent Publication No. 62-129165 Summary of the Invention [Problem to be solved by the invention]

[0007] The air table type density separator of Patent Document 1 requires the diameter of the holes for blowing air to be equal to or larger than a predetermined value in order to blow out a sufficient amount of air from the table surface. However, particles with a diameter smaller than the predetermined value may fall through the holes for blowing out air. If particles fall through the holes, they cannot be separated. In other words, the air table type density separator of Patent Document 1 has difficulty separating small diameter particles.

[0008] The cyclone separator of Patent Document 2 has difficulty separating three or more types of components.

[0009] Therefore, an object of the present disclosure is to provide an air table type density separation device and separation method that can improve the accuracy of separating particles having small particle sizes and three or more types into each type. [Means for solving the problem]

[0010] (1) An air table type density separation device according to one embodiment of the present disclosure includes a first bottom plate that slopes downward in a first direction in which a plurality of separation objects flow from an inlet for the separation objects and in a second direction intersecting the first direction, and at least one baffle plate that extends in the second direction on the first bottom plate. The first bottom plate has first holes through which gas blown from the back surface to the front surface passes. The diameter of the first holes on the back surface of the first bottom plate is larger than that of at least some of the separation objects among the plurality of separation objects. The diameter of the first holes on the front surface of the first bottom plate is larger than that of the first holes on the back surface of the first bottom plate.

[0011] (2) The air table type density separator described in (1) above may further include a second bottom plate located on the back side of the first bottom plate. The second bottom plate may have second holes through which gas passes. The diameter of the second holes may be smaller than the diameter of the first holes on the back side of the first bottom plate.

[0012] (3) In the air table type density separator described in (1) or (2) above, the diameter of the plurality of objects to be separated may be 0.01 mm to 0.5 mm, and the height of the baffle plate from the first bottom plate may be 5.0 mm to 7.5 mm.

[0013] (4) In the air table type density separator according to any one of (1) to (3) above, the plurality of objects to be separated may be used refractories.

[0014] (5) A separation method according to one embodiment of the present disclosure is a method for separating a plurality of separation objects by density using an apparatus including: a first bottom plate that slopes downward in a first direction in which the plurality of separation objects flow from an inlet for the separation objects and in a second direction intersecting the first direction; and at least one baffle plate extending in the second direction on the first bottom plate, the first bottom plate having a hole that penetrates from the back surface to the front surface of the first bottom plate, the first hole having a diameter at the back surface of the first bottom plate that is larger than that of at least some of the plurality of separation objects and a diameter at the front surface of the first bottom plate that is larger than that at the back surface of the first bottom plate. The separation method includes the steps of: introducing the plurality of separation objects into the inlet; flowing a gas from the back surface of the first hole toward the front surface; vibrating the first bottom plate; and separating and recovering the plurality of separation objects by density on the side of the first bottom plate opposite the inlet. [Effects of the Invention]

[0015] According to the air table type density separation device and separation method of the present disclosure, the particle size is small and the accuracy of separating three or more types of particles into each type is improved. [Brief explanation of the drawings]

[0016] [Figure 1A] FIG. 1 is a perspective view illustrating a configuration example of an air table type density separator according to an embodiment of the present disclosure. [Figure 1B] FIG. 1B is a side view of the baffle plate of FIG. 1A. [Figure 2A] FIG. 10 is a plan view showing an example of a bottom plate having holes. [Figure 2B] FIG. 2B is an enlarged view of FIG. 2A. [Figure 2C] 2C is a cross-sectional view taken along the line CC in FIG. 2B. [Figure 3A] FIG. 10 is a perspective view showing a configuration example of an air table type density separator further provided with a partition plate. [Figure 3B] FIG. 3B is a view taken along the arrow A in FIG. 3A. [Figure 4A] 10A and 10B are top and side views showing a plain woven bottom plate according to a comparative example. [Figure 4B] 10A and 10B are a top view and a side view showing a plain woven tatami bottom plate according to a comparative example. [Figure 5] 10 is a graph showing an example of a separation result according to the present embodiment. [Figure 6] 10 is a graph showing the separation results according to a comparative example. [Figure 7] 1 is a graph comparing the separation results of the present example and the comparative example. [Figure 8] 10 is a graph comparing separation results when the height of the baffle plate is changed. DETAILED DESCRIPTION OF THE INVENTION

[0017] (Configuration example of an air table type density separator) The air table type density separation device according to the present disclosure will be described below with reference to the drawings. Each drawing is a schematic diagram and may differ from the actual device. Furthermore, the following embodiments exemplify devices or methods for embodying the technical idea of ​​the present disclosure, and are not intended to limit the configuration to the following. In other words, the technical idea of ​​the present disclosure can be modified in various ways within the technical scope described in the claims.

[0018] The separation target material separated by the air table type density separation device according to the present disclosure includes slag line (SL) material X (see FIG. 1A) and metal line (ML) material Y (see FIG. 1A) contained in spent refractory. In other words, the separation target material may include spent refractory. The density of the SL material X is lower than the density of the ML material Y. The separation target material may be crushed into granules in advance using a jaw crusher, bucket crusher, or the like. Generally, the particle size of the separation target material is preferably 50 mm or less. However, in cases where the gravel is mixed and stuck together before crushing, such as gravel in a concrete block, the particle size is preferably twice the particle size of the gravel or less.

[0019] <Air table type density separator 100 equipped with baffle plate 6> As illustrated in FIG. 1A, an air table type density separator 100 according to one embodiment of the present disclosure includes a bottom plate 2, side plates 4a and 4b, and a baffle plate 6.

[0020] The bottom plate 2 is configured so that the objects to be separated move on the bottom plate 2 from an inlet for the objects to be separated to an outlet for the objects to be separated. The side of the bottom plate 2 indicated by the white arrow representing the objects to be separated corresponds to the inlet. The side of the bottom plate 2 opposite to the side corresponding to the inlet corresponds to the outlet. The bottom plate 2 functions as a path along which the objects to be separated move from the inlet to the outlet. The direction from the inlet for the objects to be separated toward the outlet is also referred to as the first direction or movement direction. The direction intersecting the first direction or movement direction is also referred to as the second direction or width direction.

[0021] The side plates 4a and 4b extend from the inlet to the outlet so as to sandwich the bottom plate 2 from both sides in the second direction, and define a path along which the objects to be separated move. That is, the objects to be separated move on the bottom plate 2 from the inlet to the outlet within an area defined by the side plates 4a and 4b.

[0022] The baffle plate 6 extends in the second direction between the side plate 4a and the side plate 4b. The baffle plate 6 is disposed so as to be spaced apart from the side plate 4a located above the inclination of the end slope 10 and to be in contact with the side plate 4b located below the inclination of the end slope 10. The number of baffle plates 6 is not limited to two, and may be one, or three or more. As shown in FIG. 1B, the baffle plate 6 is configured so that the height (h1) from the bottom plate 2 on the side closer to the side plate 4b is lower than the height (h2) from the bottom plate 2 on the side closer to the side plate 4a.

[0023] The bottom plate 2 is arranged so as to have a slope that descends from the inlet to the outlet and a slope that descends from the side plate 4a to the side plate 4b. The slope that descends from the inlet to the outlet is also called a side slope 8. The slope that descends from the side plate 4a to the side plate 4b is also called an end slope 10.

[0024] 2A, 2B, and 2C, the bottom plate 2 includes a first bottom plate 21 and a second bottom plate 22. The bottom plate 2 may include only the first bottom plate 21 without including the second bottom plate 22. Below, a configuration example in which the bottom plate 2 includes both the first bottom plate 21 and the second bottom plate 22 will be described.

[0025] The first bottom plate 21 has a front surface 211 and a back surface 212. The first bottom plate 21 has a plurality of holes 214 penetrating between the front surface 211 and the back surface 212. The holes 214 of the first bottom plate 21 are also referred to as first holes. The holes 214 correspond to spaces defined by the side surfaces 213. As shown in FIG. 2C , the diameter (D1) of the holes 214 on the front surface 211 is larger than the diameter (D2) of the holes 214 on the back surface 212. The cross-sectional shape of the holes 214 may be an inverted trapezoid or a tapered shape whose diameter increases from the back surface 212 to the front surface 211. The shape of the holes 214 may be an inverted truncated cone.

[0026] The second bottom plate 22 has a front surface 221 and a back surface 222. The second bottom plate 22 has a plurality of holes 224 penetrating between the front surface 221 and the back surface 222. The holes 224 of the second bottom plate 22 are also referred to as second holes. The holes 224 correspond to spaces defined by the side surfaces 223. As shown in FIG. 2C , the diameter (D3) of the holes 224 is smaller than the diameter (D2) of the holes 214 in the back surface 212 of the first bottom plate 21. The second bottom plate 22 is configured such that one or more holes 224 are located within one hole 214 of the first bottom plate 21. The second bottom plate 22 may be configured such that at least four holes 224 are located within one hole 214 of the first bottom plate 21. By locating a plurality of holes 224 within one hole 214 of the first bottom plate 21, the flow of air flowing into the hole 214 can be rectified.

[0027] The diameter (D1) of the hole 214 on the front surface 211 side of the first bottom plate 21 may be at least twice the diameter (D2) on the back surface 212 side. The diameter (D2) of the hole 214 on the back surface 212 side of the first bottom plate 21 may be, for example, 0.2 mm to 2.0 mm. The diameter (D3) of the hole 224 in the second bottom plate 22 may be, for example, 0.1 mm to 0.2 mm.

[0028] The air table type density separation apparatus 100 is configured to blow air from the back surface 222 of the second bottom plate 22 toward the front surface 211 of the first bottom plate 21 through the holes 224 and 214. The direction of the blown air flow is indicated by an arrow. The air table type density separation apparatus 100 may be equipped with a pump for blowing out air, or may be connected to a pipe or device for supplying compressed air. The air may be dry air, a gas such as nitrogen, or a mixed gas.

[0029] The bottom plate 2 is configured to vibrate in a direction substantially parallel to the extending direction of the baffle plates 6. The air table type density separator 100 may further include a vibrating device that vibrates the bottom plate 2.

[0030] As described above, the baffle plate 6 is disposed so as to be spaced apart from the side plate 4a located above the inclination of the end slope 10, and to be in contact with the side plate 4b located below the inclination of the end slope 10. In addition, the height (h1) of the baffle plate 6 from the bottom plate 2 on the side closer to the side plate 4b is lower than the height (h2) of the baffle plate 6 from the bottom plate 2 on the side closer to the side plate 4a. The technical significance of configuring the baffle plate 6 in this way will be explained below.

[0031] The air table type density separator 100 can separate objects according to their density by vibrating the bottom plate 2 and blowing air through the holes 214. Specifically, the objects are subjected to different forces according to their density as they move from the inlet to the outlet, causing them to move along different paths, and are separated according to their density by being discharged from different positions of the outlets that expand in the second direction.

[0032] When separating the low-density SL material X and the high-density ML material Y, the low-density SL material X is more strongly affected by the airflow blowing out from the holes 214 in the first bottom plate 21 than by the vibration of the bottom plate 2, and is subjected to a force downward along the end slope 10, i.e., from side plate 4a to side plate 4b. As a result, the low-density SL material X moves along a path closer to side plate 4b, which is located below the end slope 10. On the other hand, the high-density ML material Y is more strongly affected by friction with the bottom plate 2, and is subjected to a force upward along the end slope 10, i.e., from side plate 4b to side plate 4a. As a result, the high-density ML material Y moves along a path closer to side plate 4a, which is located above the end slope 10. As the SL material X moves along a path closer to side plate 4b and the ML material Y moves along a path closer to side plate 4a, the SL material X and the ML material Y are discharged from different positions at the discharge port and separated. The area of ​​the discharge port closer to side plate 4a is also referred to as the high-density discharge port. The area of ​​the outlet that is close to the side plate 4b is also called a low-density outlet.

[0033] Furthermore, the SL material X and ML material Y introduced through the inlet form a sediment layer on the inlet side of the baffle plate 6. The high-density ML material Y accumulates in the layer of the sediment layer closest to the bottom plate 2, i.e., the lower layer of the sediment layer. The low-density SL material X accumulates in the layer of the sediment layer farthest from the bottom plate 2, i.e., the upper layer of the sediment layer. Because the baffle plate 6 contacts the side plate 4b and the height (h1) of the baffle plate 6 from the bottom plate 2 on the side plate 4b side is low, the low-density SL material X accumulated in the upper layer of the sediment layer moves over the baffle 6 on the side plate 4b side in the first direction (movement direction) and is discharged from the low-density discharge port. On the other hand, the ML material Y accumulated in the lower layer of the sediment layer has difficulty climbing over the baffle 6 on the side plate 4b side and is blocked by the baffle plate 6. In other words, the portion of the baffle plate 6 on the side plate 4b side functions as a dam for the ML material Y. The ML material Y is blocked by the baffle plate 6 on the side of the side plate 4b, making it difficult for it to move toward the low-density discharge port. As a result, the ML material Y is less likely to be mixed into the SL material X discharged to the low-density discharge port. In other words, the purity of the SL material X discharged to the low-density discharge port is increased.

[0034] 1B, the height (h1) of the baffle plate 6 on the side of side plate 4b is preferably 1 / 20 or more and 1 / 2 or less of the height (h2) on the side of side plate 4a. When the height (h1) is 1 / 20 or more of the height (h2), the proportion of ML material Y mixed in with the SL material X discharged to the low-density discharge outlet is further suppressed. When the height (h1) is 1 / 2 or less of the height (h2), the SL material X can pass through the baffle plate 6 smoothly and move more easily toward the discharge outlet.

[0035] When the particle size of the objects to be separated is known in advance, the height (h1) of the baffle 6 on the side plate 4b side is preferably 0.5 to 3 times the arithmetic mean of the particle size of the objects to be separated. When the height (h1) is 0.5 to 3 times the arithmetic mean of the particle size of the objects to be separated, the purity of the SL material X discharged from the low-density discharge port is further increased. When the height (h1) is 3 to 3 times the arithmetic mean of the particle size of the objects to be separated, the layer of SL material X accumulated on the inlet side of the baffle 6 becomes thinner. As the layer of SL material X becomes thinner, the SL material X becomes more likely to float due to the airflow blown out from the holes 214 of the first bottom plate 21, and is less likely to remain on the bottom plate 2. As the SL material X is less likely to remain on the bottom plate 2, separation of the objects to be separated is promoted.

[0036] The height (h2) of the baffle 6 on the side plate 4a side is preferably set so that the difference in height between the portion where the height from the bottom plate 2 is greatest and the portion where the height from the bottom plate 2 is least is greater than 1 / 10 of the value obtained by dividing the difference by the number of baffles 6 set on the bottom plate 2. By setting the height (h2) in this manner, it becomes difficult for objects to be separated to get over the portion of the baffle 6 at height h2 from the bottom plate 2 at positions away from both ends of the baffle 6, i.e., near the center on the bottom plate 2 in the second direction. Since it becomes difficult for objects to be separated to get over the portion of the baffle 6 at height h2 from the bottom plate 2, the low-density SL material X and the high-density ML material Y are less likely to be mixed with each other. As a result, the separation accuracy of the low-density SL material X is improved.

[0037] When the particle diameters of the objects to be separated are known in advance, the height (h2) of the baffle 6 on the side plate 4a side is preferably greater than 1 / 2 the arithmetic mean of the particle diameters of the objects to be separated. When the height (h2) is greater than 1 / 2 the arithmetic mean of the particle diameters of the objects to be separated, it becomes even more difficult for the objects to be separated to get over the part of the baffle 6 at height h2 from the bottom plate 2. Since it becomes even more difficult for the objects to be separated to get over the part of the baffle 6 at height h2 from the bottom plate 2, it becomes even more difficult for the low-density SL material X and the high-density ML material Y to become mixed with each other. As a result, the separation accuracy of the low-density SL material X is further improved.

[0038] The particle size of the separation object described above may be specified as either the smallest mesh size of a sieve, as specified in JIS Z8801-1 or the like, through which the entire amount of the separation object passes, or the arithmetic mean of the particle size of the crushed separation object approximated by the circle-equivalent diameter.

[0039] The baffle plate 6 may be configured to include, on its side surface viewed from the first direction, a first rectangular region on the side plate 4a side, a second rectangular region on the side plate 4b side, and a connection region connecting the first rectangular region and the second rectangular region. Furthermore, the baffle plate 6 preferably has a slope in the connection region such that the height from the bottom plate 2 gradually decreases from the first rectangular region toward the second rectangular region. Specifically, the slope angle (θ) in the connection region is preferably 10° or more and 60° or less. When the slope angle (θ) is 10° or more, the ML material Y is less likely to be mixed with the SL material X. When the slope angle (θ) is 60° or less, the SL material X can smoothly pass through the baffle plate 6 and easily move toward the discharge port.

[0040] The thickness of the baffle 6 may be any thickness as long as it is not broken or bent by the load applied to the baffle 6 by the objects to be separated accumulated on the inlet side of the baffle 6. The number of baffle 6 may be one, or two or more. By using two or more baffle plates 6, the separation accuracy of the objects to be separated is further improved.

[0041] The width of the gap between the baffle plate 6 and the side plate 4a is preferably 2.5 times or more the particle size of the material to be separated. The width of the gap is the length of the gap in the second direction (width direction) of the bottom plate 2. When the width of the gap between the baffle plate 6 and the side plate 4a is 2.5 times or more the particle size of the material to be separated, the ML material Y can easily pass through the baffle plate 6. Furthermore, the width of the gap between the baffle plate 6 and the side plate 4a is preferably 0.5 times or less the length of the bottom plate 2 in the second direction at the position where the baffle plate 6 is provided, i.e., the width of the bottom plate 2. When the width of the gap between the baffle plate 6 and the side plate 4a is 0.5 times or less the width of the bottom plate 2, the ML material Y is less likely to be mixed with the SL material X at the low-density discharge port.

[0042] The inclination angle (α) of the side slope 8 is not particularly limited and may be, for example, 1° or more and 20° or less. The inclination angle (β) of the end slope 10 is also not particularly limited and may be, for example, 1° or more and 20° or less.

[0043] When air passes through the holes 214 of the first bottom plate 21, a pressure loss occurs in the holes 214 because the diameter (D1) of the holes 214 on the front surface 211 is larger than the diameter (D2) of the holes 214 on the back surface 212. The pressure loss further reduces the pressure on the front surface 211 side of the holes 214. As a result, the difference between the pressure on the front surface 211 side of the holes 214 and the pressure on the back surface 212 side of the holes 214 becomes larger than when the through-holes are simply cylindrical.

[0044] Because the difference in pressure between the front surface 211 side and the back surface 212 side of the hole 214 is large, the separation material 1 to be separated is less likely to enter the hole 214 than if the through-holes were simply cylindrical. Even if the separation material 1 does enter the hole 214, a force acts in a direction toward the front surface 211 of the hole 214 due to the pressure difference between the front surface 211 side and the back surface 212 side of the hole 214. As a result, the separation material 1 is returned to the front surface 211 side of the hole 214 and is more likely to exit from the hole 214.

[0045] Because the separation raw material 1 is difficult to enter into the hole 214, even if the diameter (D4) of the separation raw material 1 is smaller than the diameters (D1 and D2) of the hole 214 in the first bottom plate 21 and the diameter (D3) of the hole 224 in the second bottom plate 22, the separation raw material 1 can move through the holes 214 and 224 to the discharge outlet without falling.

[0046] On the other hand, the diameters (D1 and D2) of the holes 214 and the diameter (D3) of the holes 224 in the second bottom plate 22 must be large enough to ensure a sufficient flow rate without increasing the flow rate of the blown air too much. This is because if the flow rate of the blown air is too fast, small particles of separation material will be blown away. Even if the diameter (D4) of the separation material 1 is small, the separation material 1 is unlikely to fall through the holes 214 and 224. This allows the air table type density separator 100 to separate small particles of separation material according to their density while ensuring the necessary diameters of the holes 214 and 224. As a result, the separation accuracy of small particles of separation material is improved.

[0047] As described above, the bottom plate 2 may include only the first bottom plate 21 without the second bottom plate 22. When the bottom plate 2 includes only the first bottom plate 21 without the second bottom plate 22, the air table type density separation apparatus 100 is configured to blow air through the holes 214 from the back surface 212 of the first bottom plate 21 toward the front surface 211. Even in this case, when air passes through the holes 214 of the first bottom plate 21, a pressure loss occurs in the holes 214 because the diameter (D1) of the holes 214 on the front surface 211 is larger than the diameter (D2) of the holes 214 on the back surface 212. Due to the pressure loss, the separation material 1 is less likely to fall through the holes 214 even if the separation material 1 is smaller than the diameters (D1 and D2) of the holes 214 of the first bottom plate 21. Since the separation material 1 is less likely to fall through the holes 214, the air table type density separator 100 can separate small particle diameter objects according to their density while ensuring the necessary diameters (D1 and D2) of the holes 214. As a result, the separation accuracy of small particle diameter objects is improved.

[0048] The air table type density separator 100 according to the embodiment described above can separate low-density SL material X and high-density ML material Y, i.e., particles of two different densities, at the discharge port. The air table type density separator 100 may be configured to separate particles of three or more different densities at the discharge port by appropriately setting the shape or arrangement of the baffle plates 6.

[0049] <Air table type density separator 200 further provided with a partition plate 12> 3A and 3B, the air table type density separator 200 includes a bottom plate 2, a baffle plate 6a, a baffle plate 6b, and a baffle plate 6c, a side plate 4a and a side plate 4b, and a partition plate 12. That is, the air table type density separator 200 further includes the partition plate 12 in addition to the components included in the air table type density separator 100 of FIGS. 1A and 1B. The partition plate 12 extends in a first direction (movement direction).

[0050] The bottom plate 2 is divided into a first region 2a located closer to the inlet, and a second region 2b and a third region 2c located closer to the outlet. Baffle plate 6a is installed in the first region 2a. Baffle plate 6b is installed in the second region 2b. Baffle plate 6c is installed in the third region 2c.

[0051] 1A, the baffle plate 6a extends in the second direction (width direction) between the side plate 4a and the side plate 4b, contacts the side plate 4b, and is installed so as to have a gap between it and the side plate 4a. The first region 2a is the region from the inlet to the baffle plate 6a located closest to the discharge port. In other words, the baffle plate 6a is installed in the first region 2a. The height of the baffle plate 6a from the bottom plate 2 is lower on the side of the side plate 4b than on the side of the side plate 4a, similar to the baffle plate 6 in FIGS. 1A and 1B.

[0052] The partition plate 12 extends in the first direction from the baffle plate 6a located closest to the discharge port to the discharge port. The second region 2b and the third region 2c are separated by the partition plate 12. The second region 2b is an area closer to the side plate 4b than the partition plate 12. The third region 2c is an area closer to the side plate 4a than the partition plate 12.

[0053] Baffle plate 6b extends in the second direction (width direction) between side plate 4b and partition plate 12, is in contact with side plate 4b, and is installed in second region 2b so as to have a gap between it and partition plate 12. The height of baffle plate 6b from the bottom plate 2 is lower on the side plate 4b side than on the partition plate 12 side. Baffle plate 6c extends in the second direction (width direction) between partition plate 12 and side plate 4a, is in contact with partition plate 12, and is installed in third region 2c so as to have a gap between it and side plate 4a. The height of baffle plate 6c from the bottom plate 2 is lower on the partition plate 12 side than on the side plate 4a side.

[0054] The bottom plate 2 slopes downward in the second region 2b and the third region 2c from the side plate 4a to the side plate 4b. The slope in the second region 2b is also referred to as the end slope 10b. The slope in the third region 2c is also referred to as the end slope 10c. The slope of the end slope 10b is gentler than the slope of the end slope 10c. The slope of the end slope 10b and the slope of the end slope 10c may be the same.

[0055] In the air table type density separator 200 further provided with the partition plate 12, the separation target flowing into the second region 2b is mainly low-density SL material X. However, a small amount of high-density ML material Y may also flow into the second region 2b. Here, in the second region 2b, the SL material X is further separated from the separation target mixture of SL material X and a small amount of ML material Y by the baffle plate 6b. At this time, the gentle inclination of the end slope 10b increases the purity of the SL material X moving to the discharge outlet on the side closer to the side plate 4b.

[0056] In the air table type density separator 200 further provided with the partition plate 12, the separation target flowing into the third region 2c is mainly the high-density ML material Y. However, a small amount of the low-density SL material X may also flow into the third region 2c. Here, in the third region 2c, the ML material Y is further separated from the separation target mixture of the ML material Y and a small amount of SL material X by the baffle plate 6c. At this time, the steep inclination of the end slope 10c increases the purity of the ML material Y moving to the discharge outlet on the side closer to the side plate 4a.

[0057] As described above, the air table type density separator 200 further provided with the partition plate 12 can improve separation accuracy by separating the objects to be separated in two stages.

[0058] The height of the partition plate 12 is preferably at least twice the height (h1) of the baffle plate 6b on the side plate 4b side. When the height of the partition plate 12 is at least twice h1, the objects to be separated that have flowed into the third region 2c are prevented from climbing over the partition plate 12 and entering the second region 2b.

[0059] Furthermore, the air table type density separator 200 is configured so that it can separate particles of three or more densities at the discharge port, not just two densities, by appropriately combining the partition plates 12 and the baffle plates 6.

[0060] (Example) Hereinafter, an example of separating objects to be separated using the air table type density separator 100 according to the present disclosure will be described.

[0061] The separation target includes SL material, ML material, and slag, each of which has a different density. The density of the SL material is lower than that of the ML material. The density of the slag is lower than that of the SL material. The accuracy with which the air table type density separation device 100 according to the present disclosure separates the separation target into SL material, ML material, and slag, i.e., the accuracy with which the separation target is separated into particles of three different densities, is compared with the separation accuracy of a device according to a comparative example.

[0062] The device according to the comparative example is configured so that the holes for blowing air from the bottom plate 2 are different in shape from the holes 214 in the first bottom plate 21 of the air table type density separation device 100 according to the present disclosure. Specifically, the holes provided in the bottom plate 2 in the device according to the comparative example are holes formed by plain weave as exemplified in Fig. 4A, or holes formed by plain dutch weave as exemplified in Fig. 4B. The diameter of the holes in the device according to the comparative example is approximately 1 mm to 2 mm.

[0063] On the other hand, in the air table type density separation apparatus 100 according to the present disclosure, the holes 214 provided in the first bottom plate 21 are configured so that their diameters are larger on the front surface 211 side of the first bottom plate 21 than on the back surface 212 side, as shown in Figures 2B and 2C.

[0064] A separation target containing SL material, ML material, and slag in known ratios was separated using an apparatus according to a comparative example and an air table-type density separator 100 according to the present disclosure. The SL material included silicon carbide (SiC). The specific gravity of the separation target was in the range of 1.5 to 3.0. In this example, the discharge outlet was divided into three ranges: a high-density side, a medium-density side, and a low-density side, from the side plate 4a located at the upper end of the end slope 10 toward the side plate 4b located at the lower end. The slag was expected to be discharged to the low-density side of the discharge outlet. The SL material was expected to be discharged to the medium-density side of the discharge outlet. The ML material was expected to be discharged to the high-density side of the discharge outlet.

[0065] In this example, samples of the material to be separated were prepared so that the particle size fell within a predetermined range. Specifically, samples with particle sizes falling within the range of 0.01 mm to 0.5 mm, samples with particle sizes falling within the range of 0.5 mm to 1.0 mm, and samples with particle sizes falling within the range of 1.0 mm to 2.0 mm were prepared. Separation of samples prepared so that the particle size fell within the predetermined range proceeded more efficiently than separation of samples containing particles of various particle sizes.

[0066] Samples prepared so that particle sizes fell within each range were separated using the device according to the comparative example and the air table type density separation device 100 according to the present disclosure. The test conditions were as follows: The air flow rate was adjusted so that the smallest particles among the objects to be separated would not be blown away. Processing capacity: 100 kg per hour Dimensions of bottom plate 2: inlet side 180 mm, outlet side 580 mm, length in first direction 400 mm Base plate 2 vibration frequency: 9.0Hz Amplitude of vibration of bottom plate 2: 3.5 mm Flow rate of air blown out from the hole in the bottom plate 2: 3.5 m per minute3 End slope 10 inclination angle (β): 7° Height of baffle plate 6: 5.0 mm

[0067] FIG. 5 shows an example of the separation results of the air table type density separator 100 according to the present disclosure, where the separation target material is separated into low-, medium-, and high-density outlets under the above-described test conditions. FIG. 6 shows an example of the separation results of the comparative example, where the separation target material is separated into low-, medium-, and high-density outlets under the above-described test conditions. To facilitate comparison between the separation results of the present example and the comparative example, FIG. 7 shows the separation results of the present example and the comparative example for separation target material with particle sizes of 0.01 mm to 0.5 mm. The vertical axis of the bar graphs in FIGS. 5, 6, and 7 represents the separation ratio of each outlet. The separation ratio of each outlet is the weight ratio of particles separated by being discharged into the outlet corresponding to each density. The ratios shown as target values ​​are the ratios of particles of each density contained in the separation target material before separation. In this example, the particle size of the object to be separated is adjusted to 2.0 mm to 4.5 mm, and the result of separation using the device according to the comparative example is used as the target value.

[0068] According to the graph in Fig. 5, the separation ratio according to this embodiment is close to the target value even when the particle size of the object to be separated, i.e., the separation particle size, becomes small. For example, while the target value of the separation ratio of the medium-density outlet is 64.1%, the separation ratio of the medium-density outlet according to this embodiment was 62.3% when the separation particle size was 1.0 mm to 2.0 mm, 61.0% when the separation particle size was 0.5 mm to 1.0 mm, and 57.1% when the separation particle size was 0.01 mm to 0.5 mm.

[0069] On the other hand, according to the graph of Fig. 6, the separation ratio according to the comparative example deviates from the target value when the separation particle size becomes smaller. For example, while the target value of the separation ratio of the medium-density outlet is 64.1%, the separation ratio of the medium-density outlet according to this example was 50.9% when the separation particle size was 1.0 mm to 2.0 mm, 31.0% when the separation particle size was 0.5 mm to 1.0 mm, and 32.2% when the separation particle size was 0.01 mm to 0.5 mm.

[0070] 5 and 6, the difference between the separation ratio and the target value for each of the present embodiment and the comparative example tends to increase as the particle size decreases. For comparison, the graph in FIG. 7 shows that for the smallest particle size separation targets tested, i.e., particle sizes of 0.01 mm to 0.5 mm, the difference between the separation ratio and the target value for the comparative example is greater than the difference between the separation ratio and the target value for the present embodiment. In other words, the air table type density separator 100 of the present embodiment can achieve higher separation accuracy for small particle size separation targets than the apparatus of the comparative example.

[0071] Furthermore, when separation objects having a particle size smaller than the holes were separated using the device according to the comparative example, it was confirmed that a large number of particles fell from the holes in the bottom plate 2. The amount of small particles that fell in the device according to the comparative example was greater than the amount of small particles that fell in the air table type density separator 100 according to the present embodiment. Therefore, the air table type density separator 100 according to the present embodiment is more suitable for separating small particles than the device according to the comparative example.

[0072] As described above, the air table type density separator 100 according to the present disclosure can separate objects to be separated that have a particle size smaller than the diameter of the air blowing holes with high accuracy, even at three or more densities, depending on the density of the objects.

[0073] Under the above-mentioned test conditions, the height of the baffle 6 was set to 5 mm. In order to confirm the appropriate range for the height of the baffle 6, tests were conducted to separate particles with particle sizes of 0.01 mm to 0.5 mm under multiple conditions with different heights of the baffle 6. The heights of the baffle 6 were set to 2.5 mm, 5.0 mm, 10.0 mm, and 20.0 mm. The other conditions were the same as the test conditions described above.

[0074] The separation results when the height of the baffle plate 6 is changed are shown in Figure 8. The vertical axis of the bar graph in Figure 8 represents the separation ratio of each outlet. An appropriate range for the height of the baffle plate 6 is determined so that the separation ratio of SL material separated into the medium-density outlet, out of the SL material, ML material, and slag contained in the separation target, approaches the target value of 64.1%.

[0075] According to the graph in Fig. 8, it was found that the separation ratio at the discharge outlet on the medium-density side when the height of the baffle 6 was 5.0 mm and 7.5 mm was close to the target value. On the other hand, it was found that the separation ratio at the discharge outlet on the medium-density side was significantly different from the target value when the height of the baffle 6 was 4.0 mm or less or 10.0 mm or more. Therefore, under the above-mentioned test conditions, the appropriate range of the height of the baffle 6 for bringing the separation ratio at the discharge outlet on the medium-density side close to the target value was determined to be 5.0 mm to 7.5 mm.

[0076] (summary) As described above, the air table type density separation device according to the present disclosure can separate small particle diameter objects with high accuracy.

[0077] (Separation method) The present disclosure may also be realized as a separation method. The separation method according to the present disclosure may be implemented as a method for separating a plurality of separation objects by density. An apparatus for implementing the separation method according to the present disclosure may include a first bottom plate that slopes downward in each of a first direction and a second direction in which the plurality of separation objects flow from an inlet for the plurality of separation objects, and at least one baffle plate extending in the second direction on the first bottom plate. The first bottom plate may have a first hole that penetrates from the back surface to the front surface of the first bottom plate, the first hole having a diameter on the back surface that is larger than that of at least some of the plurality of separation objects and a diameter on the front surface that is larger than the diameter on the back surface. In other words, the separation method according to the present disclosure may be implemented using an air table type density separation apparatus according to the present disclosure.

[0078] The separation method according to the present disclosure includes the steps of: feeding a plurality of objects to be separated into an inlet; flowing a gas from the rear surface of the first hole toward the front surface thereof; vibrating the first bottom plate; and separating and recovering the plurality of objects to be separated by density on the side of the first bottom plate opposite the inlet. By carrying out the separation method according to the present disclosure, small particle diameter objects to be separated can be separated with high accuracy.

[0079] Although the embodiments of the present disclosure have been described based on the drawings and examples, it should be noted that those skilled in the art could make various modifications or alterations based on the present disclosure. Therefore, it should be noted that these modifications and alterations are included within the scope of the present disclosure. For example, the functions included in each component or step can be rearranged so as not to cause logical inconsistencies, and multiple components or steps can be combined or divided into one. The embodiments of the present disclosure can also be realized as a program executed by a processor included in an apparatus or a storage medium on which a program is recorded. It should be understood that these are also included within the scope of the present disclosure. [Explanation of symbols]

[0080] 100, 200 Air table type density separator 2 Bottom plate (2a: 1st area, 2b: 2nd area, 2c: 3rd area) 21 1st bottom plate (211: front, 212: back, 213: hole side, 214: hole) 22 2nd bottom plate (221: front, 222: back, 223: hole side, 224: hole) 4a, 4b side plate 6, 6a, 6b, 6c baffle plate 8 Side Slope 10, 10b, 10c End Slope 12 Divider

Claims

1. a first bottom plate that is inclined so as to become lower in a first direction in which the plurality of separation objects flow from an inlet for the plurality of separation objects and in a second direction that intersects with the first direction; at least one baffle plate extending in the second direction on the first bottom plate; Equipped with the first bottom plate has a first hole through which gas blown from the back surface toward the front surface passes; a diameter of the first hole on the rear surface of the first bottom plate is larger than a diameter of at least some of the plurality of separation objects; a diameter of the first hole on the front surface of the first bottom plate is larger than a diameter of the first hole on the back surface of the first bottom plate; Air table type density separator.

2. Further provided is a second bottom plate located on the back surface side of the first bottom plate, the second bottom plate has a second hole through which a gas passes; The diameter of the second hole is smaller than the diameter of the first hole on the back surface of the first bottom plate. The air table type density separator according to claim 1 .

3. The diameters of the plurality of separation objects are 0.01 mm to 0.5 mm, The height of the baffle plate from the first bottom plate is 5.0 mm to 7.5 mm. The air table type density separator according to claim 2.

4. The air table type density separator according to claim 1 , wherein the plurality of objects to be separated are spent refractories.

5. A method for separating a plurality of separation objects by density using an apparatus including: a first bottom plate inclined so as to decrease in a first direction in which the plurality of separation objects flow from an inlet for the plurality of separation objects and in a second direction intersecting the first direction; and at least one baffle plate extending in the second direction on the first bottom plate; the first bottom plate having a hole penetrating from a back surface to a front surface of the first bottom plate, the first hole having a diameter on the back surface of the first bottom plate larger than that of at least some of the plurality of separation objects and a diameter on the front surface of the first bottom plate larger than that of the back surface of the first bottom plate, A step of inputting the plurality of objects to be separated into the input port; flowing a gas from the rear surface of the first hole toward the front surface; vibrating the first bottom plate; separating and recovering the plurality of separation objects according to density on an opposite side of the first bottom plate from the inlet; A separation method comprising:

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