JPH0523566A - Raw material granulation and its device - Google Patents

Abstract

PURPOSE:To enhance granulation properties and processing capability withoput effecting kneading fo pressure-tight plasticizing for which the durability of a main machine system needs to be securely maintained and remedial measures to deal with the vibration of a bracket is needed to be taken when raw material is granulated. CONSTITUTION:A raw material granulation device is composed of a stirring blender 4 which adds an adequate amount of water for granulating a raw material depending on the type of the raw material and a vibration granulation machine 5 which applies a circular vibration in a direction crossing the proceeding direction of the raw material moistened by stirring and mixing of the stirring blender 4 and rotates/masses the raw material into mini-pellets.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a raw material granulating method and apparatus.

[0002]

2. Description of the Related Art FIG. 10 is a schematic view showing a conventional sintering process. In this conventional technique, a raw material charged in a fine ore tank 1 is cut out in a fixed amount by a lower constant feeder 2, which is conveyed by a belt conveyor 3, and a mini pellet is manufactured through a kneading machine 4 and a vibrating granulator 5. There is. On the other hand, after the normal sintering raw material quantitatively cut out by the lower constant feeder 7 of the mixing tank 6 is layered and mixed on the belt conveyor 8, the above-mentioned vibration-granulated mini-pellets and the above-mentioned normal sintering raw material are mixed. Are mixed in a drum mixer 9, and these are mixed from a belt chute 12 through a feed hopper 10 and a drum feeder 11 to a pallet 14 of a DL type sintering machine 13.
Charging into the ignition furnace 15, the coke in the raw material is ignited,
Sinter.

Here, the applicant of the present invention discloses, in Japanese Patent Application No. 1-269416, the configuration of the above-mentioned kneader 4 and vibration granulator 5 as shown in FIG.
The following is disclosed.

That is, the kneading machine 4 has a large number of rods (consolidation media) 41 housed in a drum 40, a vibrator 42 is attached to both sides of the drum 40, and these are placed on a spring 43. There is. The shaker 42 is attached to both sides of the drum 40 so as to be balanced and synchronized with each other so as to rotate synchronously, and cooperates with the spring 43 to impart circular vibration to the drum 40 and the consolidation medium 41.

Further, the vibrating granulator 5 is provided with a vibrating mechanism in which a vibrating machine 52 and a spring 53 are arranged around the drum 50, similar to the kneading machine 4, and circular vibration can be applied to the drum 50. It is a thing.

Therefore, in the prior art, when the sintering raw material is pre-granulated, the raw material is kneaded in the kneading machine 4 in the first step.
Water is added to obtain a proper granulation water content, and the consolidation medium 41 in the drum 42 exerts a comprehensive action on the material particles such as consolidation, shearing, rolling, crushing, kneading by kneading, etc. Squeezing and uniform spreading of surface water, and thus the compacted and plasticized flakes are supplied to the vibrating granulator 5 in the second step, which is tumbled and granulated by the circular vibration of the drum 50. Manufactured mini pellets.

[0007]

However, the prior art has the following problems.

As a first step for granulation, a vibrating kneader using a compaction medium is used. In the case of a large amount of processing, the weight of the vibrating body becomes large and the resulting inertial force becomes large. It is a problem to secure the durability of and the measures against the vibration of the stand.

As the second step for granulation, a vibrating granulator which vibrates a drum mounted on a spring by a vibrating machine is used, and the amplitude is 7 to 8 mm from the stable vibration region of the spring. The above cannot be obtained so much, and there is a limit in improving the granulation property and the processing capacity. That is, the yield of particles having a particle size of 2 to 10 mm is as low as 60% by weight or less.

Since the vibration-granulated mini-pellets and ordinary sintering raw materials are mixed in the drum mixer, the shearing force generated between the moving layer and the stationary layer of the raw materials in the mixer causes the mini-pellets to collapse. However, the residual rate is low. Therefore, when sintering the sintering raw material on the pallet, the air permeability is poor,
This leads to reduced productivity and excessive power consumption of the main exhaust fan.

It is an object of the present invention to improve the granulating property and the processing capacity without performing the consolidation plasticization kneading which requires the durability of the machine body and the measures against the vibration of the gantry during the granulation.

Another object of the present invention is to prevent the granulated mini-pellets from collapsing during handling during sintering.

[0013]

The present invention according to claim 1 comprises a first step of adding the amount of water necessary for granulating the raw material, which is determined according to the raw material, and stirring and mixing the raw material. A raw material comprising a second step in which circular vibration is applied to the raw material moistened by stirring and mixing in the first step in a direction intersecting the advancing direction of the raw material to tumbl agglomerate the raw material to obtain mini-pellets Granulation method.

According to a second aspect of the present invention, in the method of the present invention according to the first aspect, the raw material is a sintering raw material to be supplied to a DL type sintering machine, and the raw material intersects the advancing direction of the raw material. A circular vibration with an amplitude of 10 to 30 mm in the direction is applied for 4 seconds or longer.

According to a third aspect of the present invention, in the method of the present invention according to the second aspect, the raw material is only fine iron ore containing 60% by weight or more of particles having a particle size of less than 63 μm. It is a thing.

The present invention according to claim 4 provides the invention according to claims 1 to 3.
In the method of the present invention according to any one of the above, further the amount of water added is from the amount of water necessary to make the yield of particles having a particle size of 2 to 10 mm by granulation of the raw material determined according to the raw material 80% by weight. The water content of the raw material is deducted from the water content.

According to a fifth aspect of the present invention, the amount of water required for granulating the raw material, which is determined according to the raw material, is added, and the raw material is stirred and mixed by stirring and mixing with the stirring mixer. Granulation of a raw material constituted by including a vibrating granulator for imparting circular vibration in a direction crossing the advancing direction of the raw material to the wetted raw material and rolling agglomerating the raw material to obtain mini pellets It is a device.

According to a sixth aspect of the present invention, in the apparatus of the present invention according to the fifth aspect, the agitating mixer further comprises two spiral blade shafts rotating in opposite directions in a container. The container is provided with a raw material inlet on the spiral blade shaft starting end side, a raw material discharging port on the spiral blade shaft end side, and a humidifying device downstream of the raw material charging port. is there.

According to a seventh aspect of the present invention, in the apparatus of the present invention according to the fifth aspect, the vibrating granulator supports the container by an eccentric shaft, and the raw material in the container is rotated by the eccentric shaft. It is configured to impart circular vibration.

The present invention according to claim 8 is defined by claims 1 to 4.
The mini-pets that have been vibrated and granulated by the granulation method of the raw material according to any one of 1 above, are directly sent without passing through a drum mixer,
This is a method of sintering raw materials to be charged into a pallet of a sintering machine.

[0021]

The principle of the present invention will be described with reference to the raw material water content and the binding state in a single particle due to vibration energy shown in FIG.

As shown in FIG. 2, it is known that when a fine powder raw material having a certain water content is stored in a container and vibration acceleration is applied in the direction of compressing the raw material, the density of the fine powder in the container increases. At this time, the filling state of the particles changes depending on the water content of the fine powder raw material in the container and the magnitude of the excitation energy, and the density increases according to the filling state. The graph of FIG. 2 shows this.

When the water content of the fine powder raw material is low, voids with air exist between the particles of the powder, and the powder is in a dry mixture. When the water content of the fine powder raw material is increased and vibrated, the water is uniformly and uniformly spread on the surface of the particles, voids in the air layer are eliminated, and the entire granules are in a sticky plasticized state, resulting in a dry density of the fine powder raw material. Approaches a curve with zero porosity.

When the water content further increases, the powder becomes a thick slurry. The plastic state in which the water content is less than that in the slurry state and the voids in the air layer are the smallest is called a capillary region, and the powder has the highest dry density and a high density flake state.

In order to obtain the powder in the capillary region, it is possible to obtain it by applying the vibration of the most appropriate water content and the appropriate energy according to the properties of the particles of the granules. The present invention is a method of granulating a raw material using this principle, in which in the first step, stirring and mixing are performed to add an appropriate amount of water to moisturize to an appropriate granulated water state, and A powder moistened with uniform water is obtained. Then, in a second step, circular moisture is applied to the powder that has been mixed with the proper granulation water and moistened with uniform water to cause the water in the particles to permeate to the surface. Adhesion and growth are caused, and rolling granulation is performed.

In the first step, the amount of water added to the raw material is determined from the water content (appropriate granulation water) when the yield of mini-pellets having a particle size of 2 to 10 mm is 80% by weight or more. Is the deficit of water that is subtracted from the amount of water originally held by
It depends on the brand of raw material. As an example, Kudrem ore has a water content of 8.8% and an appropriate granulation water content of 10.6%, so the added water content is 1.8%. For MBR ore, the water content is 9.5% and the proper granulation water content is 11.5%, so the added water content is 2.0%.

Therefore, according to the present invention, the following operational effects are obtained. The first step for granulation is to perform proper plasticization and kneading by a vibration-type kneader using a compaction medium, etc., and to perform proper water addition and uniform stirring and mixing, without causing vibration. Therefore, it is not necessary to secure the durability of the special machine body or take measures against the vibration of the frame.

The stirring and mixing machine used in the first step is
When the raw material is agitated and mixed by the rotation of the spiral blade shaft of the book, a uniform wet body can be obtained in a short staying time, and vibration is not generated.

The second step for granulation has an amplitude of 10-
It is as large as 30 mm, and can improve granulation property and processing capacity. That is, using only fine iron ore containing 60% by weight or more of particles having a particle size of less than 63 μm as a raw material, the particle size of 2 to
The yield of 10 mm can be increased to 80% by weight or more.

When the vibrating granulator used in the second step imparts circular vibration due to the rotation of the eccentric shaft to the raw material in the container, the amplitude is adjusted by adjusting the eccentric amount of the eccentric shaft. It is more than twice as large as the conventional one.

Further, since no excessive load is applied to the container of the vibrating granulator, the weight of the vibrating body can be reduced, and the vibration transmitted to the gantry can be reduced by providing the balance weight, so that the durability of the machine is improved. It is possible to improve and prevent the vibration of the gantry, simplify the equipment and improve the reliability of the machine.

Since the vibrating granulator is directly arranged without passing through the drum mixer by placing the vibrating granulator close to the ore feeding section of the sintering machine or the like, it is charged into the pallet of the sintering machine. , It is possible to prevent the collapse of the mini pellet during handling. As a result, the remaining rate is high and the strength of the green ball can be secured at 100 to 120 g. Therefore, when the sintering raw material is sintered on the pallet, the air permeability is good, the productivity is improved, and the power consumption of the main air exhauster can be reduced.

As a result of improving the air permeability during sintering, a large amount of PF can be blended and the raw material cost can be reduced.

[0034]

EXAMPLE FIG. 1 is a sintering process diagram showing an embodiment of the method of the present invention, FIG. 2 is a schematic diagram showing the bonding state between single particles due to the water content of raw materials and vibration energy, and FIG. FIG. 4 is a side cross-sectional view showing an example, FIG. 4 is a cross-sectional view taken along line IV-IV of FIG. 3, FIG. 5 is a perspective view showing an example of a vibrating granulator, FIG. 6 is a side view of FIG. 5, and FIG. 7 is a sectional view taken along line VII-VII of FIG. 8, FIG. 8 is a diagram showing a granulation result by the method of the present invention, FIG. 9 is a perspective view showing a conventional vibrating granulator, and FIG. 10 is a sintering process diagram of the conventional method. is there.

In the sintering process for the DL type sintering machine using the method of the present invention, as shown in FIG. 1, the fine powder raw material charged in the fine ore tank 1 is cut out in a fixed amount by the lower constant feeder 2 and Is conveyed by a belt conveyer 3 and this raw material is supplied to a stirring and mixing machine 4 to be mixed with proper granulation water and stirred and mixed so as to obtain a uniform water content. Further, this raw material is supplied to a vibrating granulator 5 to pre-granulate mini-pellets having a particle size of 2 to 10 mm and a yield of 80% by weight or more. On the other hand, ordinary sintering raw materials (returned ore, limestone, coke, powder ore, etc.) quantitatively cut by the lower constant feeder 7 of the compounding tank 6 are stacked and compounded on the belt conveyor 8 and then mixed in a drum mixer. At 9, the water is added so that the water content of the entire raw material becomes 5 to 7%, mixed by the rotation of the drum, tumbled and granulated, conveyed to the ore hopper 10, and cut out quantitatively by the drum feeder 11. Then, the vibration-granulated mini-pellets and the secondary compounding raw materials are mixed on the belt chute 12, and D
After charging to the pallet 14 of the L-type sintering machine 13, the ignition furnace 1
At 5, the coke in the raw material is ignited and sintered.

Here, the stirring and mixing machine 4 is as shown in FIGS. That is, the agitation mixer 4 has two twin U-shaped containers 18 fixed to a pedestal 17 via a pedestal 16 and two spiral blade shafts 19, which rotate in mutually opposite directions (the upper half is rotated outward). 20 are arranged side by side, and stirring blades 21 are spirally fixed to the spiral blade shafts 19 and 20. The respective spiral blade shafts 19 and 20 are supported by bearings 22 on both side shaft ends, and a drive motor 24 is connected to the shaft ends on the mining side via a shaft joint 23. Further, a raw material inlet 25 is provided on the start side of the spiral blade shafts 19 and 20 of the twin U-shaped container 18, and a raw material discharge port 26 is provided on the end side of the spiral blade shafts 19 and 20.
A humidifier 27 is provided downstream of the raw material charging port 25.

The vibrating granulator 5 is as shown in FIGS. That is, the vibrating granulator 5 is mounted on the pedestal 30.
Two eccentric shafts 33 and 34 (eccentricity e) are supported via bearings 31 and 32, and a cylindrical or trough-shaped container 35 is supported by these eccentric shafts 33 and 34. Incidentally, 36 is a main bracket, 37 is a sub bracket, and 38 is a connecting pin. The eccentric shaft 33 is driven by a drive motor 40 connected via a shaft coupling 39, and the eccentric shaft 34 is driven synchronously with the eccentric shaft 33 via a timing belt 41.

As a result, the vibrating granulator 5 applies the vibration acceleration 3G to the raw material in the container 35 by the rotation of the eccentric shafts 33 and 34.
Circular vibration up to 10G (amplitude 10 to 30mm, frequency 600 to 1000 times /
Minutes).

At this time, the vibrating granulator 5 supports the container 35 substantially horizontally on the pair of front and rear main brackets 36, and imparts a circular vibration diagonally intersecting the longitudinal direction of the container 35, thereby A spiraling movement force is applied to the raw material to feed the raw material from the input port 42A side to the discharge port 42B side.

The vibrating granulator 5 supports the container 35 on a pair of front and rear main brackets 36 in an inclined manner (downward gradient of 10 to 20 degrees toward the charging port 42B), as shown by a chain line in FIG. In addition, circular vibration perpendicular to the longitudinal direction of the container 35 may be applied to feed the raw material in the container 35 from the inlet 42A side to the outlet 42B side by gravity.

Next, the granulation results of the sintering raw material supplied to the DL type sintering machine according to the present invention, particularly the raw material only of fine iron ore containing 60% by weight or more of particles having a particle size of less than 63 μm will be described.

In FIG. 8 (A), a circular vibration having an amplitude of 16 mm and a constant vibration frequency of 900 times / minute is applied to the trough-shaped container of the vibration granulator 5,
Moreover, the retention time was determined by variously changing the trough length, and the relationship between this retention time and the yield of green balls with a particle size of 2 to 10 mm in the granulated product is shown. From this, the particle size 2-10
It is recognized that a retention time of 4 seconds or more is required to obtain a yield of 80% by weight or more for mm.

Further, FIG. 8 (B) shows that the container of the vibrating granulator 5 is subjected to a circular vibration with a vibration frequency of 900 times / minute and a dwell time of 5 seconds at a constant, and the amplitude is variously changed. Particle size in product
It shows the relationship with the yield of 2 to 10 mm green balls. From this, as the amplitude is increased, the particle size becomes 2 to 10
Although the yield of particles having a diameter of 2 to 10 mm is improved, in order to obtain a yield of 80% by weight or more for particles having a diameter of 2 to 10 mm, an amplitude of 10 to 30 mm, preferably
15mm or more is considered appropriate. When obtaining a yield of 80% by weight or more for particles with a particle size of 2 to 10 mm, the square trough has an amplitude of 10 to
It is recognized that the amplitude of 25 mm and the cylinder of 15 to 30 mm are appropriate.

Further, FIG. 8 (C) shows the case where the container of the vibrating granulator 5 is subjected to a circular vibration with an amplitude of 16 mm, a vibration frequency of 900 times / min, and a retention time of 5 seconds for various amounts of raw material input. The relationship between the raw material layer thickness and the yield of green balls having a particle size of 2 to 10 mm in the granulated product is shown. The thinner the raw material layer, the better, but 10 mm or less is considered appropriate.

According to the above embodiment, the following effects (1) to (4) are obtained. The first step for granulation is to perform proper plasticization and kneading by a vibration-type kneader using a compaction medium, etc., and to perform proper water addition and uniform stirring and mixing, without causing vibration. Therefore, it is not necessary to secure the durability of the special machine body or take measures against the vibration of the frame.

The stirring and mixing machine 4 used in the first step is
When the raw materials are agitated and mixed by the rotation of the two spiral blade shafts 19 and 20, a uniform wet body can be obtained in a short staying time and no vibration is generated.

The second step for granulation has an amplitude of 10-
It is as large as 30 mm, and can improve granulation property and processing capacity. That is, using only fine iron ore containing 60% by weight or more of particles having a particle size of less than 63 μm as a raw material, the particle size of 2 to
The yield of 10 mm can be increased to 80% by weight or more.

The vibration granulator 5 used in the second step is
When the circular vibration due to the rotation of the eccentric shafts 33 and 34 is applied to the raw material in the container 35, the eccentric amount of the eccentric shafts 33 and 34 is adjusted so that the amplitude is 2
It can be more than doubled.

Further, since no extra load is applied to the container 35 of the vibrating granulator 5, the weight of the vibrating body can be reduced, and the vibration transmitted to the gantry 30 can be reduced by providing the balance weight. Improvement of the durability and stand 3
Zero vibration can be prevented, equipment can be simplified and machine reliability can be improved.

By placing the vibrating granulator 5 close to the ore feeding section of the sintering machine 13, etc.
Since it is directly sent without passing through the drum mixer and is loaded into the pallet 14 of the sintering machine 13, it is possible to prevent collapse of the mini pellets in handling. As a result, the remaining rate is high and the strength of the green ball can be secured at 100 to 120 g.
Therefore, when the sintering raw material is sintered on the pallet 14, the air permeability is good, the productivity is improved, and the power consumption of the main air exhauster can be reduced.

As a result of improving the air permeability at the time of sintering, a large amount of PF can be blended and the raw material cost can be reduced.

The results of the method of the present invention are shown in Table 1 as compared with the conventional method. Here, the production rate of the sintering machine is (a) grain size
By improving the yield by 2-10 mm, the air permeability is good and the sintering time can be shortened. (B) By improving the crushing strength, there is little disintegration, the air permeability can be secured, and the sintering time can be shortened to 1.7 (ton / ton / It is thought that the time has been improved to m ² ).

[0053]

[Table 1]

[0054]

As described above, according to the present invention, during granulation, the compaction plasticizing and kneading, which requires the durability of the machine body and the measures against the vibration of the gantry, is not performed, and the granulation property and the processing capacity are improved. Can be improved.

Further, according to the present invention, it is possible to prevent the granulated mini-pellets from collapsing during handling during sintering.

[Brief description of drawings]

FIG. 1 is a sintering process diagram showing an embodiment of the method of the present invention.

FIG. 2 is a schematic diagram showing a bonding state between single particles due to a water content of a raw material and vibration energy.

FIG. 3 is a side sectional view showing an example of a stirring mixer.

FIG. 4 is a sectional view taken along line IV-IV in FIG.

FIG. 5 is a perspective view showing an example of a vibrating granulator.

FIG. 6 is a side view of FIG.

7 is a sectional view taken along line VII-VII of FIG.

FIG. 8 is a diagram showing granulation results by the method of the present invention.

FIG. 9 is a perspective view showing a conventional vibration granulator.

FIG. 10 is a sintering process diagram of a conventional method.

[Explanation of symbols]

4 stirring mixer 5 Vibration granulator 13 DL type sintering machine 18 containers 19, 20 spiral blade shaft 25 Raw material inlet 26 Raw material outlet 27 Humidifier 33, 34 Eccentric shaft 35 containers

Continued front page    (72) Inventor Suemori ▲ Akira ▼             1-chome, Mizushima Kawasaki-dori, Kurashiki-shi, Okayama             Shi) Kawasaki Steel Co., Ltd. Mizushima Steel Works (72) Inventor Shunji Iyama             1-chome, Mizushima Kawasaki-dori, Kurashiki-shi, Okayama             Shi) Kawasaki Steel Co., Ltd. Mizushima Steel Works (72) Inventor Kibun Fujii             1-chome, Mizushima Kawasaki-dori, Kurashiki-shi, Okayama             Shi) Kawasaki Steel Co., Ltd. Mizushima Steel Works (72) Inventor Yukio Konishi             1 Kawasaki-cho, Chiba-shi, Chiba Kawasaki Steel Co., Ltd.             Corporate Technology Research Division

Claims (8)

[Claims] 1. A first step of adding the amount of water necessary for granulating the raw material, which is determined according to the raw material, and stirring and mixing the raw material, and a raw material moistened by the stirring and mixing in the first step. A method of granulating a raw material, which comprises a second step of imparting circular vibration in a direction intersecting a traveling direction of the raw material and rolling-agglomerating the raw material to obtain mini-pellets. 2. The method according to claim 1, wherein the raw material is a sintering raw material to be supplied to a DL type sintering machine, and a circular vibration having an amplitude of 10 to 30 mm in a direction intersecting the advancing direction of the raw material is applied for 4 seconds or more. Granulation method of raw materials. 3. The method for granulating a raw material according to claim 2, wherein the raw material is only fine iron ore containing 60% by weight or more of particles having a particle size of less than 63 μm. 4. The amount of water added is determined from the amount of water required to bring the yield of 80% by weight of the particles having a particle size of 2 to 10 mm obtained by granulating the raw material, which is determined depending on the raw material. 4. The method of granulating a raw material according to claim 1, wherein the water content is the amount of water deficit less than. 5. A stir mixer for adding the amount of water necessary for granulating the raw material, which is determined according to the raw material, and stirring and mixing the raw material, and the raw material moistened by stirring and mixing with the stir mixer. A granulating apparatus for raw materials, which is provided with a vibrating granulator for imparting circular vibration in a direction intersecting with the advancing direction of the above and rolling-agglomerating the raw material to obtain mini-pellets. 6. The agitator / mixer comprises two spiral blade shafts that rotate in mutually opposite directions side by side in a container, a raw material inlet is provided on the spiral blade shaft starting end side of the container, and the spiral blade shaft end is formed. The raw material granulating apparatus according to claim 5, wherein the raw material discharging port is provided on the side, and the humidifying device is provided on the downstream side of the raw material charging port. 7. The apparatus for granulating a raw material according to claim 5, wherein the vibrating granulator supports the container by an eccentric shaft, and imparts circular vibration to the raw material in the container by rotation of the eccentric shaft. . 8. A mini-pet vibrated and granulated by the method for granulating a raw material according to any one of claims 1 to 4, which is directly fed without passing through a drum mixer and charged into a pallet of a sintering machine. Sintering method.