KR20210037409A - Apparatus for particle uniformity - Google Patents

Abstract

The present invention relates to a particle homogenization device, comprising: a distributor; and a cutting blade. The distributor includes a body portion, an upper cover, a lower cover and an opening and closing portion. The upper cover includes a raw material introduction part to which a raw material slurry is supplied and a gas inlet part to which a gas is supplied. The lower cover includes an outlet through which the raw material slurry is discharged. The opening and closing portion is provided at the lower part of the outlet to open and close the outlet depending on whether gas is supplied. The cutting blade is located on the lower side of the lower cover of the distributor, and to cut the raw material slurry discharged through the outlet.

Description

Particle homogenization device {APPARATUS FOR PARTICLE UNIFORMITY}

The present invention relates to a particle homogenizing apparatus, and more particularly, to an apparatus for homogenizing the columnar particles of strontium ferrite sintered magnets.

Ferrite sintered magnets are widely applied to the conversion of electro-mechanical energy such as speakers, permanent magnet motors, moving coil devices, generators, rotating machines, and microphones, and are also widely used in storage media. As a representative ferrite sintered magnet, strontium (Sr) ferrite (SrFe ₁₂ O ₁₉ ) having a hexagonal M-type magnetoplumbite structure is known. The sintered strontium ferrite magnet is made of iron oxide and a carbonate of strontium (Sr) as raw materials, and is manufactured relatively inexpensively by powder metallurgy.

BACKGROUND ART In recent years, in accordance with consumer demand, high performance of ferrite sintered magnets has been demanded for the purpose of miniaturization, weight reduction, and high efficiency of parts in automotive electronic parts, parts for electric devices, and the like. _{In particular, strontium with high coercive force (H cJ} ), which is not demagnetized by a strong diamagnetic field when thinned, while maintaining a _{high residual magnetization density (B r} ) in motors used in automotive electronic parts. Ferrite sintered magnets are in demand.

In general, the process of manufacturing a sintered strontium ferrite magnet proceeds in the following order: compounding, calcination, coarse pulverization, mixing (fine mixing), pulverization, shaping in a magnetic field, drying, sintering, and processing. The characteristic grade is determined according to the residual magnetization density and the degree of coercivity, and the two have a trade-off relationship. Among them, the residual magnetization density is closely related to _{the saturation magnetization (M s} ) value that increases according to the degree of strontium ferrite (crystallinity) in the sintering step of the sintered strontium ferrite magnet.

_{Conventionally, in order to improve the saturation magnetization (M s} ) of sintered strontium ferrite magnets, methods such as using high-purity iron oxide, performing a calcination temperature at a high temperature of 1,280° C. or higher, or adding a dispersant have been studied. However, in the case of using high-purity iron, saturation magnetization can be improved, but there is a problem that the price increases as the purity of iron oxide increases, and saturation magnetization is achieved by increasing the crystallinity of strontium ferrite when the calcination step is performed at a high temperature. It can be improved, but there is a disadvantage in that the energy cost is high. In addition, in the case of using a dispersant, it is helpful to increase the crystallinity of strontium ferrite, but the type is limited, and there is a problem that it prevents the column phase from being densely stacked.

Accordingly, there is a need for research to solve such a conventional problem and to manufacture a sintered strontium ferrite magnet having excellent coercivity and saturation magnetization.

KR 2015-0075422 A

The problem to be solved in the present invention is to solve the problems mentioned in the technology behind the background of the invention, in order to manufacture a sintered strontium ferrite magnet with improved magnetic properties such as coercivity and saturation magnetization. An apparatus for homogenizing the particle size can be provided.

That is, the object of the present invention is to homogenize the columnar particles of the sintered strontium ferrite magnet by using the particle homogenizing apparatus according to the present invention in the sintering step when manufacturing the sintered strontium ferrite magnet.

According to an embodiment of the present invention for solving the above problems, the present invention is a distributor; And a cutting blade, wherein the distributor includes a body part, an upper cover, a lower cover, and an opening/closing part, and the upper cover includes a raw material introduction part supplied with a raw material slurry and a gas introduction part supplied with a gas, and the lower cover Includes an outlet through which the raw material slurry is discharged, and the opening and closing part is provided at a lower portion of the outlet to open and close the outlet according to whether or not gas is supplied, and the cutting blade is located under the distributor, and discharged through the outlet. It provides a particle homogenizing apparatus for cutting the raw material slurry.

The particle homogenizing apparatus according to the present invention includes a distributor and a cutting blade, and the raw material slurry supplied to the distributor is primarily cut through an opening and closing part that is opened and closed according to gas injection, and the primary cut discharged from the distributor. The raw material slurry is secondarily cut through a cutting blade installed at the lower side of the distributor, so that the raw material slurry can be cut into a uniform size. In addition, particles having a uniform size may be formed by plasticizing the raw material slurry cut to a uniform size.

In addition, when the strontium ferrite sintered magnet is manufactured by using the raw material slurry cut into uniform size through the particle homogenization device, columnar particles can be densely stacked by forming columnar particles of uniform size, and sintered through this. As the density is improved, the degree of alignment in the axial direction is increased, so that the magnetization is easily magnetized when a magnetic field is applied, and it is easy to apply to light weight and miniaturized devices.

1 is a schematic diagram showing the configuration of a distributor according to an embodiment.
2 is a schematic diagram showing an upper cover and a lower cover of a distributor according to an embodiment.
3 is a flowchart illustrating a process of applying a particle homogenizing apparatus according to an exemplary embodiment.

The terms or words used in the description and claims of the present invention should not be construed as being limited to a conventional or dictionary meaning, and the inventors appropriately explain the concept of terms in order to explain their own invention in the best way. Based on the principle that it can be defined, it should be interpreted as a meaning and concept consistent with the technical idea of the present invention.

Hereinafter, the present invention will be described in more detail with reference to FIGS. 1 to 3 below in order to help understanding the present invention.

According to the present invention, a particle homogenizing apparatus 100 is provided. The particle homogenizing device includes a distributor (100); And a cutting blade 200, wherein the distributor 100 includes a body portion 110, an upper cover 120, a lower cover 130, and an opening and closing portion 140, and the upper cover 120 is a raw material It includes a raw material introduction part 121 to which the slurry is supplied and a gas introduction part 122 to which the gas is supplied, the lower cover 130 includes an outlet 131 through which the raw material slurry is discharged, and the opening/closing part 140 is It is provided under the outlet 131 to open and close the outlet 131 depending on whether gas is supplied, and the cutting blade 200 is located under the distributor 100 and is discharged through the outlet 131 It is possible to provide a particle homogenizing device that cuts the raw material slurry.

According to an embodiment of the present invention, in the particle homogenizing device, the distributor 100 may be provided to distribute the supplied raw material slurry in a predetermined size.

The raw material slurry may include a raw material component for manufacturing a strontium ferrite sintered magnet. For example, the sintered strontium ferrite magnet may include a grain boundary phase that is present between the columnar phase and the columnar phase made of strontium ferrite having a hexagonal M-type magnetoplumbite structure and surrounds the columnar phase. In general, a magnetic material, particularly a sintered magnet, is composed of a plurality of compounds, and a compound that determines the properties (physical properties, magnetic properties, etc.) of the magnetic material is defined as a columnar phase. The columnar phase in the present invention, that is, the strontium ferrite topcoat having a hexagonal M-type magnetoplumite structure, and the physical properties and magnetic properties of the ferrite sintered magnet of the present invention are determined. In this case, when the X-ray diffraction of the ferrite plasticizer is measured under general conditions, the X-ray diffraction pattern of the M-type magnetoplumbite structure of the hexagonal crystal is mainly observed. Say.

The raw material slurry may include iron oxide and strontium carbonate as components for forming the columnar particles of the sintered strontium ferrite magnet. For example, the strontium ferrite particles forming the columnar phase _{are labeled as SrFe 12} O ₁₉ , so that 12 iron ions may exist per molecule. In this case, the magnetic properties of the strontium ferrite are based on the magnetic moment of iron (Fe) ions, and 8 of the 12 Fe ions have an upward spin direction and four downward spin directions. The sum of pure spins per molecule is 4. In general, in strontium ferrite, iron ions are trivalent (Fe ³⁺ ), with 5 3d electrons (spin magnetic moment), and a total of 20 spin magnetic moments (the sum of 5 spin moments x pure spins). It becomes the source of magnetism (saturation magnetization) of strontium ferrite magnets. At this time, in order to increase the saturation magnetization value, which is the source of magnetism, the saturation magnetization is improved by increasing the total spin magnetic moment by substituting an element having a lower spin magnetic moment or a non-magnetic element than the iron ion in the downward spin direction of the iron ion. I can. For example, in the strontium ferrite particles, some of iron (Fe) is selected from the group consisting of cobalt (Co), zinc (Zn), nickel (Ni), manganese (Mn), magnesium (Mg) and chromium (Cr). It may be substituted with one or more. As a more specific example, in the strontium ferrite particles, a part of iron may be substituted with cobalt.

In the strontium ferrite particles forming the columnar phase, a part of strontium (Sr) may be replaced with a rare earth element. For example, as the rare earth element, at least one selected from the group consisting of lanthanum (La), neodium (Nd), praseodium (Pr), cerium (Ce), and the like may be included. And the like. In the strontium ferrite particles, by substituting a part of strontium with a rare earth element, there is an effect of securing price competitiveness and maintaining high magnetic force even at high temperatures. As a more specific example, in the strontium ferrite particles, strontium may be substituted with lanthanum.

The raw material slurry is prepared by mixing raw materials in a blender (C1) and separated through a centrifugal separator (C2), and may be supplied using a pump (C3).

According to an embodiment of the present invention, the distributor 100 may include a body portion 110, an upper cover 120, a lower cover 130, and an opening and closing portion 140.

According to an embodiment of the present invention, the body portion 110 is for accommodating the supplied raw material slurry and may have a cylindrical shape, but is not limited thereto.

The volume of the body portion 110 may be ^{0.002 m 3} to 0.03 m ^3. For example, the volume of the body portion 110 may be 0.002 m ³ to 0.015 m ³ , 0.003 m ³ to 0.01 m ^3, or 0.004 m ³ to 0.007 m ³ . The body portion 110 has a volume within the above range, thereby receiving a continuously supplied raw material slurry and periodically discharging it.

According to an embodiment of the present invention, the upper cover 120 serves to seal the upper surface of the body portion 110 and at the same time includes a raw material introduction portion 121 and a gas introduction portion 122, The raw material slurry and gas may be supplied into the body part 110.

The raw material introduction part 121 is a component for supplying the raw material slurry into the body part 110, and may be formed as a raw material transport pipe for transporting the raw material slurry, and the raw material transport pipe is formed on the upper cover 120. Since it is connected to the opening, the raw material slurry transferred through the pipe may pass through the opening of the upper cover 120 and be supplied into the body part 110.

The flow rate of the raw material slurry supplied through the raw material introduction unit 121 may be 500 kg/hr to 3000 kg/hr. For example, the flow rate of the raw material slur supplied through the raw material introduction unit 121 may be 500 kg/hr to 2500 kg/hr, 1000 kg/hr to 2500 kg/hr, or 1500 kg/hr to 2000 kg/hr. . By supplying the raw material slurry at a flow rate within the above range, the problem of clogging the flow due to the filling of the raw material slurry in the distributor is prevented, and the raw material slurry can be continuously distributed.

The raw material introduction part 121 may be formed in the center of the upper cover 120.

The gas introduction part 122 is a configuration for supplying gas into the body part 110, and may be formed as a gas transfer pipe for transferring gas, and the gas transfer pipe is formed in an opening formed in the upper cover 120. Since it is connected, the gas transferred through the pipe may pass through the opening of the upper cover 120 and be supplied into the body part 110.

The gas supplied through the gas introduction part 122 may be air. For example , the air may be supplied at a temperature of 400 °C to 600 °C. As described above, the raw material slurry may be heated using high-temperature air. In this case, the air may be to reuse the high-temperature air discharged from the reactor C4, which will be described later, and energy can be saved through this.

The gas introduction part 122 may be formed between the raw material introduction part 121 formed in the center of the upper cover 120 and the outer circumferential surface of the upper cover 120.

One to ten gas introduction units 122 may be formed. For example, 1 to 8, 1 to 5, or 2 to 5 gas introduction units 122 may be formed.

Gas supplied into the body portion 110 through the gas introduction portion 122 may be periodically supplied. For example, the gas supplied through the gas introduction unit 122 may be supplied 0.1 to once per second. For example, the gas supplied through the gas introduction unit 122 may be supplied 0.1 to 0.8 times per second, 0.1 to 0.6 times, or 0.3 to 0.6 times per second.

In addition, when the gas is supplied once through the gas introduction unit 122, the flow rate of the supplied gas may be 0.1 kg/hr to 5 kg/hr. For example, the flow rate of the gas supplied at one time of supply may be 0.5 kg/hr to 4 kg/hr, 0.7 kg/hr to 2.5 kg/hr, or 1 kg/hr to 1.5 kg/hr. As described above, by periodically supplying gas into the body portion 110 through the gas introduction portion 122, the raw material slurry contained in the body portion 110 can be discharged in a uniform size.

The upper cover 120 may have a raw material introduction part 121 formed at a center thereof, and a plurality of gas introduction parts 122 may be formed at a predetermined interval around the raw material introduction part 121. In this way, by configuring the upper cover 120, the raw material slurry can be supplied and discharged smoothly.

According to an embodiment of the present invention, the lower cover 130 may include an outlet 131 for discharging the raw material slurry. The shape, diameter, and number of the discharge ports 131 are not particularly limited unless there is a problem in discharging the raw material slurry.

For example, 1 to 10 outlet ports 131 provided in the lower cover 130 may be formed. For example, 1 to 8, 2 to 7, or 4 to 7 outlets 131 may be formed.

According to an embodiment of the present invention, the opening/closing part 140 may be configured to open or close the outlet 131 of the lower cover 130. The opening/closing part 140 may be installed to correspond to a lower portion of an area in which the outlet 131 of the lower cover 130 is formed. The structure and shape of the opening and closing part 140 are not particularly limited.

The opening/closing part 140 may open/close the outlet 131 depending on whether gas is supplied. Specifically, the opening and closing unit 140 operates to open the outlet 131 when the gas is periodically supplied through the gas introduction unit 122, and can operate to close the outlet 131 while the gas is not supplied. have.

By periodically supplying gas through the gas introduction part 122, the opening/closing part 140 can be controlled, through which the discharge port 131 that periodically opens the raw material slurry accommodated in the body part 110 of the distributor 100 ) Can be discharged in a uniform size. Specifically, the distributor 100 may first cut and discharge the supplied raw material slurry.

The average size of the raw material slurry discharged from the body portion 110 through the outlet 131 may be 15 mm to 180 mm. For example, the average size of the raw material slurry discharged through the outlet 131 may be 30 mm to 150 mm, 45 mm to 100 mm, or 45 mm to 75 mm.

According to an embodiment of the present invention, the cutting blade 200 may be formed under the distributor 100 to cut the raw material slurry discharged through the outlet 131 of the distributor 100. Specifically, the raw material slurry is firstly cut through the distributor 100 and discharged to an average size of 45 mm to 75 mm as described above, and the raw material slurry discharged from the distributor 100 is cut off the cutting blade 200. It can be cut secondary by using. Through this, the size of the raw material slurry supplied to the particle uniforming apparatus according to the present invention can be uniform.

The cutting blade 200 may be a rotary cutting blade 200. Specifically, the rotary cutting blade 200 has a central axis, one or more blades are formed based on the central axis, and may be operated in a method of rotating about the central axis. For example, the rotary cutting blade 200 may have one to four blades formed based on a central axis.

The rotary cutting blade 200 may rotate at a speed of 10 rpm to 200 rpm. For example, the rotational speed of the rotary cutting blade 200 may be 20 rpm to 150 rpm, 20 rpm to 100 rpm, or 30 rpm to 80 rpm. By rotating the cutting blade 200 at the rotational speed within the above range, the raw material slurry discharged from the distributor 100 can be uniformly cut.

The average size of the raw material slurry discharged from the particle homogenizing device may be 45 mm to 75 mm. For example, the average size of the raw material slurry discharged from the distributor 100 using the cutting blade 200 may be 10 mm to 50 mm, 15 mm to 35 mm, or 15 mm to 25 mm. have.

As described above, the raw material slurry discharged from the particle homogenizing apparatus according to the present invention may have a very uniform size. When the raw material stream cut into such a uniform size is plasticized, plasticizer particles having a uniform size can be produced.

According to an embodiment of the present invention, the particle homogenizing device may be used in a plasticizing step during a strontium ferrite manufacturing process.

For example, the manufacturing process of the strontium ferrite sintered magnet may include a first mixing step of mixing a columnar component raw material; Plasticizing the mixture mixed in the first mixing step; A second mixing step of mixing the plasticizer particles; And pulverizing and sintering the mixture mixed in the second mixing step, and in this case, the particle homogenizing apparatus according to the present invention may be used in the step of plasticizing the mixture mixed in the first mixing step. have.

In the first mixing step of mixing the columnar component raw material, as the columnar component raw material, a strontium precursor and an iron precursor may be included. The strontium precursor may include at least one selected from the group consisting _{of Sr(NO 3} ) ₂ , SrCO ₃ , SrCl ₂ , SrSO ₄ and Sr(OH) _2. As a more specific example, the strontium precursor may include strontium carbonate (SrCO ₃ ). In addition, the iron precursor may include at least one selected from the group consisting of _{Fe(NO 3} ) ₃ , FeCO ₃ , FeCl ₃ , Fe ₂ O ₃ , FeCl ₂ and Fe(OH) _3. As a more specific example, the iron precursor may include iron oxide (Fe ₂ O ₃ ). Such a main component raw material can be supplied to the blender (C1) and blended.

In addition, the mixed raw material of the columnar component removes some of the water contained in the slurry using a centrifugal separator (C2), and the separated raw material slurry passes through a pump (C3) and is installed inside the reactor (C4). It may be supplied to the raw material introduction unit 110 of the particle homogenizing device. In this case, the solid content concentration of the raw material slurry supplied to the raw material introduction unit 110 may be 55% to 65%.

The raw material slurry may be supplied to the reactor C4 through the particle homogenizing device according to the present invention. Specifically, the raw material slurry is discharged through the distributor 100, and the raw material slurry discharged from the distributor 100 is cut by the cutting blade 200 and then falls into the reactor C4. In this way, the raw material slurry supplied into the reactor C4 may be plasticized to form powder particles.

The reactor C4 may be a chemical vapor deposition reactor. For example, the chemical vapor deposition reactor may be selected from a rotary kiln reactor or a fluidized bed reactor. Specifically, the reactor (C4) may be a rotary kiln reactor.

The rotational speed of the reactor C4 may be 1 rpm to 5 rpm, the residence time of the raw material slurry may be 1 hour to 2 hours, and the operating temperature may be 1,000 °C to 2,000 °C.

The particle homogenization device according to the present invention is installed inside the reactor (C4) operated at a high temperature as described above, but has an opening and closing part 140, so that the raw material slurry is directly exposed to high temperature and hardens to prevent clogging of the outlet. I can.

In the reactor, plasticizer particles may be produced by plasticizing the mixed raw material slurry. Through the plasticizing step, impurities in the raw material sulery are removed, residual carbon dioxide, etc. may be removed, and crystallinity of strontium ferrite may be improved.

The average size of the plasticizer particles may be 1 µm to 10 µm, 2 µm to 8 µm, or 3 µm to 5 µm. As described above, in the case of manufacturing strontium ferrite sintered magnets using the particle homogenizing apparatus according to the present invention, the particles can be uniformized to a size within the above range.

The plasticized plastic body particles may be manufactured into strontium ferrite sintered magnets by further going through a second mixing step, a pulverization step, and a sintering step.

The second mixing step may be performed by including the plasticizer particles and the grain boundary raw material. In this case, the grain boundary raw material is not particularly limited as long as it does not impede the dense lamination of the columnar phase and the magnetic properties of the strontium ferrite sintered magnet.

In addition, after the second mixing step, a pulverization step may be further included as necessary. For example, the pulverization step may be performed in a wet manner to obtain a pulverized powder. The grinding time and grinding method are not particularly limited. In this way, the average particle size of the fine particles formed through the pulverizing step may be 1 µm to 5 µm, 1 µm to 4 µm, or 1.5 µm to 3 µm.

By sintering the finely pulverized particles, a sintered strontium ferrite magnet may be manufactured. For example, the sintering method is not particularly limited, and may be performed by any one method selected from the group consisting of atmospheric pressure sintering, hot pressing, hot hydrostatic sintering, gas pressure sintering, and spark plasma sintering.

In this way, when the sintered strontium ferrite magnet is manufactured using the particle homogenizing device according to the present invention, the average particle diameter of the columnar particles of the sintered strontium ferrite magnet is 1.5 µm to 5.0 µm, 2.0 µm to 5.0 µm, or 2.5 to 3.5. It may be μm. By controlling the average particle diameter of the columnar particles within the above range, the columnar phases can be densely stacked, and in this case, the degree of alignment in the axial direction for magnetization increases, so that when a magnetic field is applied, there is an effect of being easily magnetized, and the coercive force is increased. You can get the effect.

In addition, the sintered density of the sintered strontium ferrite magnet may be 4.9 g/cm ³ to 5.3 g/cm ³ , 4.9 g/cm ³ to 5.25 g/cm ³ or 4.9 g/cm ³ to 5.2 g/cm ³ . By having an improved sintering density within the above range, the volume can be greatly reduced, and through this, it is possible to reduce size and weight along with excellent magnetic properties, and can be applied as a core component of various products requiring miniaturization and weight reduction.

In addition, the strontium ferrite sintered magnet can prevent pores from being formed in the strontium ferrite sintered magnet by densely stacking the columnar phases. Even if pores are formed, it can be induced to form micropores having an average size of 200 nm to 800 nm, 200 nm to 750 nm, or 200 to 700 nm. Through this, in the case of manufacturing a sintered strontium ferrite magnet using a conventional dispersant, the columnar phase is not densely stacked, and thus a problem in which a large number of macropores are generated due to evaporation of the dispersant in the heating step can be solved.

As described above, the strontium ferrite sintered magnet manufactured using the particle homogenizing device according to the present invention has high-performance magnetic properties, and through this, has an advantage that can be applied to various fields.

The manufacturing process of the strontium ferrite sintered magnet is only described as an example for application of the particle homogenizing apparatus according to the present invention, and it is obvious to a person skilled in the art that various changes and modifications are possible within the scope and spirit of the present invention. The scope of the present invention is not limited only by these.

As described above, the particle homogenization apparatus according to the present invention has been shown in the description and drawings, but the description and drawings in the description describe and show only the essential components for understanding the present invention, and the processes shown in the description and drawings and In addition to the apparatus, processes and apparatuses not separately described and not shown can be appropriately applied and used to implement the particle uniforming apparatus according to the present invention.

100: divider
110: body
120: top cover
121: raw material introduction section
122: gas introduction
130: lower cover
131: outlet
140: opening and closing part
200: cutting blade

Claims (12)

Divider; And a cutting blade,
The distributor includes a body part, an upper cover, a lower cover and an opening and closing part,
The upper cover includes a raw material introduction part to which a raw material slurry is supplied and a gas introduction part to which a gas is supplied,
The lower cover includes an outlet through which the raw material slurry is discharged,
The opening/closing part is provided at the lower part of the discharge port to open/close the discharge port according to whether or not gas is supplied,
The cutting blade is positioned under the distributor, and the particle homogenizing device cuts the raw material slurry discharged through the discharge port. The method of claim 1,
The particle homogenizing device is installed inside the reactor. The method of claim 2,
The raw material slurry supplied to the reactor is supplied through a particle homogenizing device. The method of claim 2,
The operation temperature of the reactor is 1,000 ℃ to 2,000 ℃ particle homogenization device. The method of claim 1,
The flow rate of the raw material slurry supplied to the distributor through the raw material introduction unit is 500 kg / hr to 3000 kg / hr particle uniforming device. The method of claim 1,
The upper cover has a raw material introduction portion is formed in the central portion, and a plurality of gas introduction portions are formed at a predetermined interval around the raw material introduction portion. The method of claim 1,
Particle homogenization device that the gas supplied to the distributor through the gas introduction portion is periodically supplied. The method of claim 1,
Particle homogenization device having 1 to 10 outlets of the lower cover. The method of claim 1,
The opening and closing part opens the outlet when gas is supplied to the distributor, and closes the outlet when gas is not supplied. The method of claim 1,
The cutting blade is a particle homogenizing device which is a rotary cutting blade. The method of claim 1,
The particle homogenizing device having an average size of the raw material slurry discharged from the particle homogenizing device is 45 mm to 75 mm. The method of claim 1,
The particle homogenization device of the raw material slurry containing iron oxide and strontium carbonate.

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