JP5573547B2 - Ferromagnetic separator - Google Patents

Description

  The present invention relates to a technique for separating a ferromagnetic material from a heterogeneous mixed powder containing a ferromagnetic material, and is applied, for example, to the technical field of separating iron from slag produced in an iron making process.

  In an iron making process (particularly, hot metal preliminary treatment or converter process), a huge amount of slag (iron slag) is generated. These slags are produced by the reaction and generation of calcium-based additives added to remove impurities and unwanted elements in hot metal and molten steel, and the slag contains a large amount of iron as well as the removed elemental compounds. . Most of the slag forms are massive, and the size of the slag is large and some hundreds of millimeters.

  As described above, since the slag contains a large amount of iron, studies on recycling of the slag have been actively conducted. In addition, reuse of slag itself as, for example, a calcium-containing material has been studied.

  For example, in order to separate and collect iron from slag and mix it with scrap in the converter process to make a cold iron source, first, a large slag lump of several hundred mm is shaped with a sieve (grid type sieve) called grits. Sort out. Next, the small slag block that has passed through the grind-type sieve has an iron block and a non-ferrous block fixed, so it is crushed with a Hanmark lasher or a rod mill to a size of several hundred μm to several tens of mm. Promotes the separation of non-ferrous and simple substances. Thereafter, the iron content and the non-ferrous content are separated by a magnetic separator. As the magnetic separator, a hanging type, a drum type, a pulley type, or the like is used.

  As a means for separating iron, the slag may be heated and crushed by controlling the subsequent cooling time. Depending on the cooling time, it is possible to crush and separate only the non-ferrous lump that is fixed without crushing the iron lump. Or it can be atomized to about several tens of μm.

  Needless to say, if atomization progresses in any of the methods, the separation of iron and non-ferrous metals will progress.

JP 2006-142136 A Japanese Patent Laid-Open No. 10-130041

  In order to improve the separation concentration of iron from steelmaking slag, it is necessary to advance the separation of iron and non-ferrous. As described above, as the atomization progresses, the separation of the single substance progresses. Therefore, the slag lump is repeatedly mechanically crushed to reduce the particle size. Alternatively, the particle size may be reduced by heat treatment.

  On the other hand, in general, when the particle size is reduced in the conventional magnetic separator, as shown in FIG. 9, a embracing phenomenon in which non-ferrous particles (non-magnetic particles) are sandwiched between magnets and iron-containing particles (magnetic particles). In addition, agglomeration due to dry atomization tends to occur. And it becomes easy to occur that non-magnetic particles are separated on the magnetized side by these phenomena, or conversely, the magnetic particles are separated on the non-magnetized side, so that the separation concentration (separation accuracy) can be improved. It becomes difficult. Therefore, the supply speed of the mixed powder (mixed powder of magnetic particles and nonmagnetic particles in FIG. 9) to the magnetic separator is extremely slowed to reduce the layer thickness of the different types of mixed powder on the apparatus. Such a device is necessary. However, since it is necessary to process several tons to several tens of tons of iron slag per hour, it is not practical to use a magnetic separation device that must extremely slow the supply speed.

  On the other hand, Patent Document 1 discloses a technique for separating the iron and non-ferrous components without crushing the slag lump, but the separation process is complicated and causes an increase in processing costs.

  Further, as a particle separation method that can avoid agglomeration due to dry atomization, a wet process as disclosed in Patent Document 2 has been devised. However, the waste liquid treatment cost is enormous in the wet process.

  The present invention has been made in view of the circumstances as described above. For example, as in the case of separating iron from atomized iron slag, the ferromagnetic material is separated from the heterogeneous mixed powder containing the ferromagnetic material. It is an object of the present invention to provide a ferromagnetic separator that can efficiently separate a ferromagnetic.

  As described above, in order to improve the separation concentration of iron from steelmaking slag, first, it is necessary to atomize the ironmaking slag and promote the separation of iron and nonferrous as a single substance.

  Next, iron and non-ferrous components will be separated from atomized steelmaking slag, but since ironmaking slag is premised on mass processing (several tons to several tens of tons per hour), as described above, Magnetic sorting has to slow down the processing speed due to particle embracing phenomenon and particle agglomeration phenomenon, and cannot be applied to such a case where large-scale processing is assumed.

  Therefore, the present inventors solve the problems that occur when separating a ferromagnetic material from a heterogeneous mixed powder containing a ferromagnetic material, such as when separating iron from atomized iron slag as described above. In order to do this, we conducted an intensive study. As a result, when separating a ferromagnetic material from a heterogeneous mixed powder containing a ferromagnetic material, an air flow or water flow in which the heterogeneous mixed powder is dispersed is subjected to a force that changes the magnitude depending on the mass of the powder. (For example, centrifugal force) is used for separation into a separation chamber (mass difference separation chamber) that performs separation, and in the mass difference separation chamber, magnetic force is applied to the ferromagnetic material in the mixed powder of different types in addition to centrifugal force. I came up with the idea of making it work.

  That is, for example, in a heterogeneous mixed powder in which two types of powder are mixed, if there is a range that overlaps the mass distribution of one powder in each type of powder, In the mass difference class, it is difficult to properly separate and recover, and the recovery amount and recovery rate of each powder must be reduced. Therefore, using the fact that one powder is a ferromagnetic material and the other powder is a non-magnetic material, the mass distribution of one powder is the same as the mass distribution of the other powder. For the ferromagnetic materials in the overlapping range, it is possible to appropriately separate and collect the ferromagnetic material and the non-magnetic material by applying a magnetic force in addition to the centrifugal force. Thereby, the collection amount / recovery rate can be improved.

  In the case of recovering high-purity slag particles by separating and removing iron particles from a mixed powder of slag particles (non-magnetic material) and iron particles (ferromagnetic material). (Or / and when collecting high-purity iron particles) will be described with reference to FIG.

  First, as shown in FIG. 8 (a), when looking at the mass distribution of a single particle, the range of M1 with a small mass is only slag, and the range of M3 with a large mass is only iron. In the range of M2, slag and iron are overlapped.

  In this case, if high-purity slag is to be recovered by mass difference separation, as shown in FIG. 8 (b), if the mass difference separation position is at the boundary between M1 and M2, the mass is within the range of M1 on the smaller side. Slag can be recovered with 100% purity. However, since the slag of M2 is isolate | separated to the side with larger mass in that case, the quantity of slag collect | recovered is limited.

  Therefore, in order to increase the amount of slag recovered, it is conceivable to move the mass difference separation position by ΔM to the side with the larger mass, as shown in FIG. In this case, the slag in the region S1 in the figure is also collected on the smaller mass side and the amount of slag collected is increased. At the same time, the iron in the region S2 in the diagram is also collected on the smaller mass side. End up. As a result, the purity of the slag collected on the smaller mass side is greatly reduced.

  On the other hand, as shown in FIG. 8D, when the mass difference separation is performed by moving the mass difference separation position by ΔM to the larger mass side, the magnetic force is applied to the iron particles in the range of ΔM. When the iron in the region S3 in the figure is separated and removed to the side with the larger mass, the iron recovered on the side with the smaller mass is only that in the region S4 in the figure. Become. As a result, a large amount of high-purity slag can be recovered on the side where the mass is small. When importance is attached to the purity of iron recovered on the large mass side, for example, the mass separation position is set at the boundary between M2 and M3, and the magnetic force is applied in the same manner, so that at least a part of iron of M2 is on the large mass side Collect it.

  Ideally, if the mass difference separation position is at the boundary between M2 and M3, and all the iron in the range of M2 can be separated to the larger mass side, all the slag is 100% pure on the smaller mass side. And all the iron can be recovered with a purity of 100% on the side of larger mass.

  An example of a method based on the above-described concept is a method of applying a magnetic force to the centrifugal separation using the air current or the swirling of the water flow. Specifically, different types of mixed powders are dispersed in an air flow or water flow, and the air flow or water flow swirls to form a flow path that applies centrifugal force to the powder, and the ferromagnetic material is magnetized in the direction of the centrifugal force. In this method, one or more magnetic field generators are arranged along the flow path so that centrifugal force and magnetic force act on the ferromagnetic material.

  That is, first, the heterogeneous mixed powder containing the ferromagnetic material is conveyed by a fluid (air flow or water flow), thereby making the heterogeneous mixed powder dispersed. In particular, when the fluid is a water stream, the dispersion effect is large only by administering the different kinds of mixed powders in the water stream. When the fluid is an air flow, a dispersed state is realized by using a diffusion plate or diffusion compressed air. Then, a shearing force acts on the transport particles (heterogeneous mixed powder) due to a turbulent flow effect in the fluid (air stream or water stream) during transport, and a single separated state in which aggregation is solved is realized. Then, a flow path is formed so that the fluid carrying the different mixed powder swirls to apply a centrifugal force to the different mixed powder, and a magnetic force is applied to the direction in which the centrifugal force is applied. As a result, each particle of the mixed powder of different types in a dispersed state (single separated state) moves to the outside of the swirl by centrifugal force, and finally decelerates and is captured in contact with the wall of the flow path. Due to the effect of the magnetic force acting there, the magnetic force is selectively applied to the centrifugal force only to the ferromagnetic particles. Therefore, the separation effect is increased with respect to the ferromagnetic particles, and the separation can be performed up to the ferromagnetic particles having a small diameter, that is, a small mass.

  As described above, only separation based on the difference in mass cannot be performed when the masses of the ferromagnetic material and the non-magnetic material particles other than the ferromagnetic material are the same. Therefore, the present invention has made it possible to dramatically improve the separation efficiency of the ferromagnetic component by applying the magnetic force only to the ferromagnetic component using the magnetic force in combination.

  Based on the above concept, the present invention has the following features.

  [1] A ferromagnetic separation device for separating a ferromagnetic material from a heterogeneous mixed powder containing a ferromagnetic material, wherein an air flow or a water flow in which the heterogeneous mixed powder is dispersed is swirled to dissimilar mixed powder A flow path for applying centrifugal force to the body, and a magnetic field generator disposed at one or more locations along the flow path so that the ferromagnetic body receives a magnetic force in the direction of the centrifugal force. A separator for separating a ferromagnetic material, wherein centrifugal force and magnetic force are applied.

  [2] The ferromagnetic separating apparatus according to [1], wherein the magnetic field generating device has a configuration capable of adjusting a magnitude of magnetic flux density acting on a space through which the ferromagnetic material passes. .

  [3] The strong magnetic force according to [2], wherein the magnetic field generator is configured to repeat the magnitude of the magnetic flux density acting on the space through which the ferromagnetic material passes at regular intervals. Magnetic material separation device.

  [4] Separation of ferromagnetic material according to [3], wherein the magnetic flux density is reduced after reducing the flow velocity of the air flow or water flow in which the different types of mixed powder guided to the separation chamber are dispersed. apparatus.

  [5] The ferromagnetic separating apparatus according to [4], wherein the magnetic flux density is increased before increasing the flow velocity of the air flow or water flow.

  In the present invention, when the ferromagnetic material is separated (centrifugated) from the heterogeneous mixed powder containing the ferromagnetic material, the magnetic force acting only on the ferromagnetic material is caused to act in the direction of the centrifugal force. The separation accuracy of the ferromagnet is greatly improved, and the ferromagnet can be separated more efficiently than in the conventional case where the ferromagnet is separated by magnetic separation. As a result, the ferromagnetic material can be recycled in large quantities and at high speed.

It is a figure which shows Embodiment 1 of this invention. It is a figure which shows Embodiment 2 of this invention. It is a figure which shows Embodiment 3 of this invention. It is a figure which shows Embodiment 4 of this invention. It is a figure which shows Embodiment 4 of this invention. It is a figure which shows Embodiment 4 of this invention. It is a figure which shows Example 1 of this invention. It is a figure which shows the fundamental view of this invention. It is a figure which shows the problem of a prior art (general magnetic selection).

  Embodiments of the present invention will be described with reference to the drawings.

  In the following embodiments, the ferromagnetic material is separated from the mixed powder containing the ferromagnetic material, as in the case of separating iron from atomized iron slag. A method of obtaining a mixed powder containing different types of iron will be described by taking as an example the case of atomizing iron slag.

  As a method of atomizing iron slag, the first method of atomization is mechanical pulverization. For mechanical pulverization of iron slag, a ball mill, a rod mill, a jet mill, a pin mill, or the like is used for fine pulverization after rough pulverization with a hammer crusher or jaw crusher as a coarse pulverizer. The second atomization method is thermal pulverization (heat treatment pulverization). The iron slag is heated to about 1000 to 1300 ° C. and then slowly cooled.

  In this way, a heterogeneous mixed powder (a mixture of ferromagnetic particles and nonmagnetic particles) containing a ferromagnetic material can be obtained.

  In the present invention, particles that can be separated by appropriate magnetic separation may be regarded as ferromagnetic particles, and the particles other than the ferromagnetic particles may be regarded as substantially non-magnetic particles.

  In the following embodiments, the ferromagnetic particles are separated from the heterogeneous mixed powder (a mixture of ferromagnetic particles and nonmagnetic particles) containing the ferromagnetic material obtained as described above. I will decide. Here, as in the case of iron and iron slag, it is assumed that the ferromagnetic particles have a larger mass than the non-magnetic particles.

[Embodiment 1]
Embodiment 1 of the present invention is shown in FIG.

  As shown in a schematic plan view in FIG. 1 (a) and a schematic elevation view in FIG. 1 (b), the ferromagnetic separator 11 according to the first embodiment includes a different kind of mixed powder (ferromagnetic particles). Cylindrical swirl in which a fluid (airflow or water stream) carrying a mixture of 1 and nonmagnetic particles 2 swirls to apply a centrifugal force to the ferromagnetic particles 1 and the nonmagnetic particles 2 A flow path 12 and a magnetic field generator 13 disposed at a plurality of locations along the cylindrical swirl flow path 12 are provided so that the ferromagnetic particles 1 receive a magnetic force in the direction of the centrifugal force.

  In addition, as the cylindrical swirl flow path 12, a generally known cyclone can be used. Alternatively, it may be a swirling channel having a shape similar to that.

  The magnetic field generator 13 uses a permanent magnet or an electromagnet. The magnetic field only needs to be generated at a plurality of locations along the cylindrical swirl flow path 12, and the larger the number, the greater the effect. The strength of the magnetic field may be selected from about 100 G (Gauss) to 20000 G (Gauss) depending on the separated particle size.

  In the ferromagnetic separator 11 configured as described above, first, the different kind mixed powder (mixture of the ferromagnetic particles 1 and the non-magnetic particles 2) is conveyed by a fluid (air flow or water flow). Therefore, the mixed powder of different types is in a dispersed state. That is, a shearing force acts on the different types of mixed powders due to the turbulent flow effect of the fluid during conveyance, and a single separated state in which aggregation is solved is realized.

  In addition, the fluid flowing through the cylindrical swirl flow path 12 swirls to apply a centrifugal force to the ferromagnetic particles 1 and the non-magnetic particles 2, and a magnetic field generator 13 in the same direction as the centrifugal force acts. Thus, a magnetic force acts on the ferromagnetic particles 1. For this reason, the ferromagnetic particles 1 and the non-magnetic particles 2 in a single separated state move to the outside of the swirl by centrifugal force, and finally come into contact with the wall 12a of the cylindrical swirl flow path 12 and are captured. However, the magnetic force is selectively applied only to the ferromagnetic particles 1 due to the magnetic force from the magnetic field generator 13 acting on the centrifugal force.

  Since the ferromagnetic particles 1 have a large mass, the acting centrifugal force is increased, so that the ferromagnetic particles 1 are likely to approach the wall 12 a of the cylindrical swirl flow path 12. On the other hand, since the non-magnetic particles 2 have a small mass, the acting centrifugal force is small, so that the non-magnetic particles 2 are positioned relatively on the center side of the cylindrical swirl flow path 12.

  As a result, the ferromagnetic particles 1 on which both centrifugal force and magnetic force act are brought into contact with the walls of the flow path and decelerated and separated into a weight-side collection box 14 provided at the lower part of the cylindrical swirling flow path 12. On the other hand, the non-magnetic particles 2 on which only the centrifugal force acts are carried on the fluid as they are, and discharged from the upper part of the cylindrical swirl flow path 12 to the lightweight side.

  Incidentally, the centrifugal force is determined by the flow velocity and the swirl diameter only by ordinary centrifugal separation, and the separation particle size is determined. For this reason, if the flow rate is increased in order to increase the separation / recovery amount of the ferromagnetic particles 1 captured by the wall 12a, the separation / recovery amount of the non-magnetic particles 2 including the ferromagnetic particles 1 also increases. The recovery concentration (separation accuracy) of the ferromagnetic particles 1 is not improved. On the other hand, in the first embodiment, the recovery amount of the ferromagnetic particles 1 can be improved by adjusting the strength of the magnetic field, so that the recovery concentration of the ferromagnetic particles 1 can be improved. It becomes.

[Embodiment 2]
A second embodiment of the present invention is shown in FIG. The basic concept of the second embodiment is the same as that of the first embodiment. However, instead of the cylindrical swirl flow path 12 in the first embodiment, a swirl flow path 22 using a spiral pipe is used, and gas is used as the liquid.

  That is, as shown in the schematic plan view of FIG. 2A and the schematic elevation view of FIG. The fluid (in this case, the airflow) in which the body particles 1 and the non-magnetic particles 2 are cast is swirled to apply centrifugal force to the ferromagnetic particles 1 and the non-magnetic particles 2. The spiral piping swirl flow path 22 and the magnetic field generators 23 arranged at a plurality of locations along the spiral piping swirl flow path 22 are provided so that the ferromagnetic particles 1 receive a magnetic force in the direction of the centrifugal force. .

  The magnetic field generator 23 uses a permanent magnet or an electromagnet. The magnetic field may be generated at a plurality of locations along the spiral piping swirl flow path 22, and the larger the number, the greater the effect. The strength of the magnetic field may be selected from about 100 G (Gauss) to 20000 G (Gauss) depending on the separated particle size.

  In the ferromagnetic separator 21 configured as described above, first, the different types of mixed powder (mixture of the ferromagnetic particles 1 and the non-magnetic particles 2) is conveyed by an air flow. The mixed powder becomes dispersed. That is, a shear force acts on the mixed powder of different types due to the turbulent effect of the air flow during conveyance, and a single separated state in which aggregation is solved is realized.

  In addition, the airflow flowing through the spiral piping swirl passage 22 swirls and centrifugal force acts on the ferromagnetic particles 1 and the nonmagnetic particles 2, and the magnetic field generator 23 extends in the same direction as the centrifugal force acts. Thus, a magnetic force acts on the ferromagnetic particles 1. Accordingly, the ferromagnetic particles 1 and the non-magnetic particles 2 that are in a single separated state move to the outside of the swirl by centrifugal force, and finally come into contact with the wall 22a of the spiral piping swirl flow path 22 and are captured. However, the magnetic force is selectively applied only to the ferromagnetic particles 1 due to the magnetic force from the magnetic field generator 23 acting on the centrifugal force.

  As a result, the ferromagnetic particles 1 on which both centrifugal force and magnetic force act are brought into contact with the walls of the flow path and decelerated, and are separated and collected in a collection box 24 provided at the outlet of the spiral piping swirl flow path 22. On the other hand, the non-magnetic particles 2 on which only the centrifugal force acts are carried as they are on the air current.

  Incidentally, the centrifugal force is determined by the flow velocity and the swirl diameter only in normal centrifugation, and the separation particle size is determined. For this reason, if the flow rate is increased in order to increase the separation / recovery amount of the ferromagnetic particles 1 trapped by the wall 22a, the separation / recovery amount of the non-magnetic particles 2 including the ferromagnetic particles 1 also increases. The recovery concentration of the ferromagnetic particles 1 is not improved. On the other hand, in the second embodiment, the recovery amount of the ferromagnetic particles 1 can be improved by adjusting the strength of the magnetic field, so that the recovery concentration of the ferromagnetic particles 1 can be improved. It becomes.

  A liquid may be used as the fluid.

[Embodiment 3]
Embodiment 3 of the present invention is shown in FIG.

  In the third embodiment, the magnetic field generator can adjust the magnitude of the magnetic flux density acting on the space through which the ferromagnetic particles pass (the magnetic flux density in the ferromagnetic particle passage space). The size of is repeated to be larger and smaller at regular intervals.

  As described above, in the first and second embodiments, permanent magnets or electromagnets are used as the magnetic field generators 13 and 23. However, the third embodiment is a case where an electromagnet is used.

  That is, as shown in a schematic plan view in FIG. 3A, in the third embodiment, as the magnetic field generators 13 and 23, five electromagnets (first electromagnet to fifth electromagnet) are arranged. Yes.

  As described above, when electromagnets are used as the magnetic field generators 13 and 23, the ferromagnetic material attracted and adhered to the wall of the magnetic field generation unit by repeating excitation (ON) and non-excitation (OFF) of the electromagnet at regular intervals. There is an advantage that the body particles 1 can be removed when de-excited. At this time, as shown in the magnetic field operation schedule in FIG. 3B, if the switching timing of the adjacent electromagnets is shifted, the state in which several electromagnets are always working can be maintained at a certain moment. It is possible to perform both the removal of particles 1 and the action of magnetic force.

  By the way, here, the magnitude of the magnetic flux density in the space passing through the ferromagnetic particles is repeated at certain intervals by repeating excitation (ON) and non-excitation (OFF) of the electromagnet at certain intervals. However, it is not limited to complete de-excitation (OFF). In other words, by changing the magnitude of the excitation current of the electromagnet to a predetermined threshold value or less every predetermined period, the magnitude of the magnetic flux density in the ferromagnetic particle passage space may be repeatedly increased and decreased every predetermined period. Good. The same applies to the following embodiments.

  Note that the electromagnet may be AC driven for the same effect. Although the frequency is arbitrary, depending on the characteristics of the electromagnet and the driving device, the magnetic field strength may be insufficient in the high frequency region. Therefore, in the case of an electromagnet having about 1000 turns with a driving power source of about 2 kW, about 50 Hz. And it is sufficient. Similar to the method of switching adjacent electromagnets as described above, by shifting the phase of adjacent electromagnets, several electromagnets can always generate a sufficiently large magnetic field at a certain moment.

  Further, in some cases, the same may be performed using permanent magnets as the magnetic field generators 13 and 23. In such a case, a mechanism capable of adjusting the position of the permanent magnet is provided, and the position of the permanent magnet is moved closer to or away from the wall of the magnetic field generation unit at regular intervals, so that the magnetic flux in the ferromagnetic particle passage space is increased. The magnitude of the density can be adjusted, and the magnitude of the magnetic flux density is repeated at regular intervals.

  In principle, it is not necessary to set the interval between excitation and de-excitation to a fixed period, but it is preferable to set the fixed period from the viewpoint of avoiding complication of operation and ensuring stable operation. However, the excitation and de-excitation periods do not have to be the same length, and the excitation / de-excitation periods may be different for each electromagnet.

  In order to repeat the magnitude of the magnetic flux density in the ferromagnetic particle passage space every predetermined period, the magnetic field generator has storage means for storing an operation schedule as shown in FIG. 3B, for example, and the magnetic field generator according to the operation schedule It is preferable to have a control means for controlling (for example, controlling the current flowing through each electromagnet, or controlling the position of each permanent magnet).

[Embodiment 4]
A fourth embodiment of the present invention is shown in FIGS.

  In the third embodiment, the magnitude of the magnetic flux density in the ferromagnetic particle passage space is repeatedly increased and decreased every certain period. However, when the magnetic flux density is reduced in a state where a fluid (water flow, air flow) in which different types of mixed powders are dispersed flows at a predetermined flow velocity, the ferromagnetic particles in which the adhesion force due to the magnetic force stops working. There is a possibility that the fluid will soar into the fluid and be collected on the lightweight side of the centrifuge.

  Therefore, in the fourth embodiment, the flow velocity of the fluid (water flow, air flow) in which the different types of mixed powders are dispersed is once reduced, and then the magnetic flux density in the ferromagnetic particle passage space is reduced. .

  Alternatively, the magnetic flux density in the ferromagnetic particle passage space is increased (returned to the original size) before the flow velocity of the fluid (water flow, airflow) is increased again (returned to the original size). I am doing so.

  For example, as shown in FIG. 4 showing a fluid and magnetic field operation schedule, when a magnet is excited (excitation ON) and a magnet is not excited (excitation OFF), the fluid is flowed at a predetermined flow rate. The state (fluid ON) and the state of completely stopping the flow of fluid (fluid OFF) are repeated, and the excitation is turned OFF after the fluid is turned OFF.

  Alternatively, as shown in FIG. 5 showing another operation schedule of the fluid and the magnetic field, the excitation is turned on before the fluid is turned on again. In other words, the fluid is turned on after the excitation is turned on.

  Instead of FIG. 4, as shown in FIG. 6 which shows another operation schedule of the fluid and the magnetic field, a threshold value is provided for the fluid flow rate, and the fluid ON state is set to a state where the fluid flow rate is equal to or higher than the threshold value. Alternatively, the state where the fluid flow velocity is less than the threshold value may be set as the fluid OFF, and the excitation OFF may be performed after the fluid is turned OFF.

  Further, a threshold value is also provided for excitation, and excitation ON and excitation OFF (including a case where excitation is not equal to the threshold value but not excitation) are determined based on the threshold value. The excitation may be turned off after turning it off.

  Incidentally, switching between fluid ON and fluid OFF can be performed by adjusting the thrust of the fluid (pump, blower) or adjusting the opening of a damper provided in the fluid flow path.

  As a result, in the fourth embodiment, even if the braking force due to the magnetic force is less likely to act on the ferromagnetic particles by reducing the size of the magnetic flux density in the ferromagnetic particle passage space, Since the fluid force to be reduced is reduced, the ferromagnetic particles are prevented from flying into the fluid, and the ferromagnetic particles are reliably recovered on the weight side of the centrifuge.

  In order to realize the operation illustrated in FIGS. 4 to 6, the ferromagnetic separation device includes a storage unit that stores an operation schedule (fluid and magnetic field), and a magnetic field generator according to the operation schedule. Control means for controlling (for example, controlling the current flowing through each electromagnet, or controlling the position of each permanent magnet), and controlling the flow velocity of the fluid according to the operation schedule (for example, the thrust and damper opening of the aforementioned pump or the like) Control means).

  Thus, in Embodiments 1 to 4 described above, when the ferromagnetic particles 1 are separated (centrifugated) from the heterogeneous mixed powder containing the ferromagnetic particles 1, they act only on the ferromagnetic particles 1. The magnetic force is applied in the direction of centrifugal force. For this reason, the separation accuracy of the ferromagnetic particles 1 is remarkably improved, and the ferromagnetic particles 1 can be separated more efficiently than in the case of separation by magnetic separation as in the prior art. As a result, the ferromagnetic material can be recycled in large quantities and at high speed.

  In the first to fourth embodiments, the mass of the ferromagnetic particles is larger than that of the non-magnetic particles, such as iron and iron slag, but in the opposite case, the above embodiments are used. What is necessary is just to change suitably the arrangement | positioning etc. of a magnetic field generator with reference to 1-4.

  In the present invention, either a gas or a liquid is suitable as the fluid. However, when a large amount of fine powder of 30 microns or less is included, it is preferable to use a water stream.

  As an example of the present invention, based on Embodiment 4 of the present invention, ferromagnetic particles (iron) are separated and removed from a mixture of ferromagnetic particles (iron) and nonmagnetic particles (slag), Non-magnetic particles (slag) were collected.

  Note that iron slag (iron average: about 10 to 20% by mass) was previously refined to an average particle size of about 250 μm by a ball mill and processed by a separator. As the separator, the ferromagnetic separator 11 shown in FIG. 1 was used.

  At that time, as shown in FIG. 6, a threshold value is set for the flow rate of the fluid. As shown in FIG. 7, the fluid is turned on when the flow rate of the fluid is 5 m / s or more. The state of less than 5 m / s was defined as fluid OFF. In addition, the state of 2000G is excitation ON, and the excitation stop state is excitation OFF. The excitation is turned off after the fluid is turned off. The order of fluid ON and excitation ON was the same as in FIG.

  For comparison, as a conventional example, a conventional centrifugal separator without a magnetic field generator is used to change a ferromagnetic particle from a mixture of ferromagnetic particles (iron) and nonmagnetic particles (slag). (Iron content) was separated and removed to recover non-magnetic particles (slag). The apparatus configuration of the conventional example is the same as that of the ferromagnetic separator 11 shown in FIG. 1 except for the magnetic field generator.

  As a result, in the conventional example, the mixing ratio of the ferromagnetic particles (iron) to the non-magnetic particles (slag) in the light-weight side recovery unit was 0.5% by mass, whereas the present invention example In this case, the rate at which the ferromagnetic particles (iron) are recovered on the light side is greatly reduced, and the mixing ratio of the ferromagnetic particles (iron) to the non-magnetic particles (slag) on the light side is 0% by mass. The separation efficiency improved dramatically by 2%.

DESCRIPTION OF SYMBOLS 1 Ferromagnetic particle 2 Non-magnetic particle 11 Ferromagnetic separator 12 Cylindrical swirl flow path (cylindrical swirl flow path)
12a Wall of cylindrical swirl flow path 13 Magnetic field generator 14 Weight side recovery box 21 Ferromagnetic material separation apparatus 22 Swirl flow path by spiral pipe (spiral pipe swirl flow path)
22a Wall of spiral piping swirl flow path 23 Magnetic field generator 24 Collection box

Claims (2)

A ferromagnetic separation device for separating a ferromagnetic material from a heterogeneous mixed powder containing a ferromagnetic material, wherein an air flow or a water flow in which the heterogeneous mixed powder is dispersed is swirled and centrifuged into the heterogeneous mixed powder. And a magnetic field generator disposed at one or more locations along the flow path so that the ferromagnetic material receives a magnetic force in the direction of the centrifugal force. Magnetic force is acting ,
The magnetic field generator has a configuration capable of adjusting the magnitude of the magnetic flux density acting on the space through which the ferromagnetic material passes, and the magnitude of the magnetic flux density acting on the space through which the ferromagnetic material passes is set at regular intervals. Separation of ferromagnetic material, characterized in that it is configured to repeat large and small, and after reducing the flow velocity of the air or water flow in which the different types of mixed powder guided to the separation chamber are reduced, the magnetic flux density is reduced. apparatus. Before increasing the velocity of the air current or water flow, ferromagnetic separation apparatus according to claim 1, characterized in that increasing the magnitude of the magnetic flux density.

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