JPH0523569A - Raw material granuation and its device - Google Patents

Abstract

PURPOSE:To enhance granulation properties and processing capability without kneading for 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 conducts the raw material moistened by stirring and mixing of the stirring blender to a flat-bottom container 35, then applies a circular vibration in a direction along the discharge direction of the raw material 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. 11 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 construction of the above-mentioned kneader 4 and vibration granulator 5 as shown in FIG.
0 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. The raw material moistened by stirring and mixing in the first step is introduced into a flat bottom container, circular vibration is applied in a direction along the discharge direction of the raw material, and the raw material is rolling agglomerated to obtain mini-pellets. It is a method of granulating a raw material, which comprises two steps.

The present invention according to claim 2 is the method according to claim 1, wherein the raw material is a sintering raw material supplied to a DL type sintering machine, and a raw material layer in a flat bottom container. With the thickness of 15 mm or less, a circular vibration with an amplitude of 10 to 30 mm in the direction along the discharge direction of the raw material is applied for 4 seconds or more.

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 60% 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. Introduce the moistened raw material into the flat bottom container,
It is a raw material granulating device configured to include a vibration granulator that imparts circular vibration in a direction along the discharge direction of the raw material and roll-agglomerates the raw material to obtain mini-pellets.

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 further supports the flat bottom container by an eccentric shaft, and the raw material in the container has an eccentric shaft. It is configured so as to impart circular vibration due to the rotation of.

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 based on the amount of water (appropriate granulation water) when the yield of mini-pellets having a particle size of 2 to 10 mm is 60% 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.

In the second step for granulation, the raw material layer thickness of the flat bottom container is reduced to 10 mm or less and the amplitude is 10 to 30.
Granularity and processing capacity are improved by circular vibrations such as mm to increase the yield of particles of 2-10 mm using only fine iron ore containing 60 wt% or more of particles with a particle size of less than 63 μmm as raw material. Can be increased to over 60% by weight.

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 flat bottom container, the eccentric amount of the eccentric shaft should be adjusted. As a result, the amplitude can be 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 sectional view showing an example, Fig. 4 is a sectional view taken along line IV-IV in Fig. 3, Fig. 5 is a side view showing an example of a vibrating granulator, Fig. 6 is a front view of Fig. 5, and Fig. 7 is a multilayer type. FIG. 8 is a side view showing the vibrating granulator, and FIG.
Of FIG. 9, FIG. 9 is a diagram showing a granulation result by the method of the present invention, FIG. 10 is a perspective view of a conventional vibrating granulator, and FIG.
FIG. 4 is a sintering process diagram of a conventional method.

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 the vibrating granulator 5 to pre-granulate mini-pellets having a particle size of 2 to 10 mm and a yield of 60% 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 are supported via bearings 31 and 32, and a wide-angle trough-shaped flat bottom container 35 is supported by these eccentric shafts 33 and 34. Incidentally, 36 is a bracket and 37 is a connecting pin.

The eccentric shaft 33 is driven by a drive motor 39 via a shaft joint 38, 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 causes the raw material in the container 35 to have a circular vibration (amplitude 10 to 30 mm;
Vibration frequency of 400 to 1000 times / min.

At this time, the plate-shaped bottom container 35 is supported substantially horizontally by the bracket 36, and the eccentric shafts 33 and 34 are subjected to circular vibration in the counterclockwise direction in FIG. The raw material is supplied from the charging unit 35A, and the raw material is fed to the raw material discharging unit 35B. Here, the raw material in the container 35 is set to have a layer thickness of 15 mm or less. As a result, the raw material in the container 35 is subjected to circular vibration with an amplitude of 10 to 30 mm for 4 seconds or more, rolling-agglomerated, and becomes mini-pellets.

The flat bottom container 35 is provided in the raw material charging section 3
For example, a downward gradient of, for example, 10 degrees may be applied from 5A toward the raw material discharge part 35B, and a clockwise circular vibration in FIG. 5 may be applied. According to this, in the container 35, the fine particles move to the raw material charging unit 35A side,
The particles are agitated to become core particles, while the grown particles are moved to the side of the raw material discharge part 35B by gravity and discharged in a state where the particle sizes are made uniform.

The multi-layer vibrating granulator shown in FIGS.
The vibrating granulator 5 of FIG. 6 is arranged in layers. Since each of the vibrating granulators 5 has a relatively flat shape, the space efficiency of the equipment can be improved due to the multilayer structure.

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. 9 (A), a circular vibration having an amplitude of 16 mm and a constant frequency of 900 times / minute is applied to the flat bottom container 35 of the vibrating granulator 5, and the trough length is variously changed to keep the staying time. 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
It was confirmed that a residence time of at least 1.5 seconds was required to obtain a yield of 60% by weight or more for 2 to 10 mm, and a retention time of 4 seconds or more was required to obtain a yield of 80% by weight or more. To be

Further, FIG. 9B shows that the flat bottom container 35 of the vibrating granulator 5 was subjected to a circular vibration with a vibration frequency of 900 times / minute and a dwell time of 5 seconds, and the amplitude was variously changed. The relationship between the amplitude and the yield of green balls with a particle size of 2 to 10 mm in the granulated product is shown. From this, the larger the amplitude, the better the yield of particles with a particle size of 2-10 mm, but
To obtain a yield of 60% or more for 10 mm, an amplitude of 5 mm or less is acceptable, but to obtain a yield of 80% or more, an amplitude of 10 to 30 m
m, preferably 15 mm or more is considered appropriate.

Further, FIG. 9C shows that the flat bottom container 35 of the vibrating granulator 5 has an amplitude of 16 mm, a vibration frequency of 900 times / minute, and a retention time.
This figure shows the relationship between the raw material layer thickness and the yield of green balls with a particle size of 2 to 10 mm in the granulated product when a constant circular vibration is applied for 5 seconds and the amount of the raw material input is variously changed. The thinner the raw material layer, the better, but 15 mm or less is considered appropriate.

According to the above embodiment, the following 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 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 is to reduce the thickness of the raw material layer of the flat bottom container 35 to 15 mm or less and set the amplitude to 5 mm.
Granularity and processing capacity are improved by circular vibration taking about mm.For example, using only fine iron ore containing 60 wt% or more of particles with a particle size of 63 μmm or more as a raw material, the yield of particles with a particle size of 2-10 mm is 60%. It can be increased to more than weight%.

Further, the grain size is reduced by circular vibration that reduces the thickness of the raw material layer to 10 mm or less and increases the amplitude to 10 to 30 mm.
The yield of 2 to 10 mm can be increased to 80% by weight or more.

The vibration granulator 5 used in the second step is
When circular vibration due to the rotation of the eccentric shafts 33, 34 is applied to the raw material in the flat bottom container 35, the eccentric shaft 33,
By adjusting the eccentricity of 34, the amplitude can be more than doubled compared to the conventional one.

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 during 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 ).

[0055]

[Table 1]

[0056]

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 side view showing an example of a vibrating granulator.

FIG. 6 is a front view of FIG.

FIG. 7 is a side view showing a multilayer vibrating granulator.

FIG. 8 is a front view of FIG. 7.

FIG. 9 is a diagram showing granulation results by the method of the present invention.

FIG. 10 is a perspective view showing a conventional vibrating granulator.

FIG. 11 is a sintering process diagram of a conventional method.

[Explanation of symbols]

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

Claims (8)

[Claims] 1. A first step of adding a necessary amount of water for granulation of 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 introducing the raw material into a flat bottom container, applying circular vibration in a direction along the discharge direction of the raw material, and rolling agglomerating the raw material to obtain mini-pellets. 2. The raw material is a sintering raw material supplied to a DL type sintering machine, and an amplitude of 10 in a direction along the discharge direction of the raw material in a state where the raw material layer thickness in the flat bottom container is 15 mm or less. The method for granulating a raw material according to claim 1, wherein a circular vibration of -30 mm is applied for 4 seconds or more. 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 to the raw material is determined from the amount of water necessary for adjusting the yield of the product having a particle size of 2 to 10 mm by granulation of the raw material, which is determined depending on the raw material, to 60% by weight. 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 tabular mixture of a stirring 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 stirring mixer. A raw material granulating apparatus configured to have a vibrating granulator that is introduced into a bottom container and is subjected to circular vibration in a direction along the discharge direction of the raw material to roll-agglomerate 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 raw material according to claim 5, wherein the vibrating granulator is configured to support the flat bottom container by an eccentric shaft and impart circular vibration to the raw material in the container by rotation of the eccentric shaft. Granulator. 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.