JP3304676B2 - Method for producing sintered ore and its sintering machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing sinter by a droidroid type sintering machine and an improvement of the sintering machine.

[0002]

2. Description of the Related Art As a sintering machine in the steelmaking industry, a Dwyroid type sintering machine is widely used. In this type of sintering machine, a compounding material is melted and a grade bar (fire) of a sintering pallet is melted. Grid) to prevent it from burning
For the purpose of preventing the compounding raw material, which is a fine particle having an average particle size of about 1 to 3 mm, from dropping from the gap of the grade bar into the wind box, first, a bed bedding (particle size:
9-18 mm of a product sintered ore) is charged in a layer with a predetermined thickness, and then the compounding raw material is charged in a layer on the bedding ore, and then the surface of the compounding raw material is ignited and turned downward. The fuel (usually coke breeze) contained in the sintering raw material is burned by inhalation, and the heat of combustion melts the blended raw material.
After forming into a massive sintered mass (hereinafter referred to as a sinter cake), cooling, pulverization, and sieving are performed to obtain a particle size of 3 to 50 m.
A blast furnace raw material called sinter of about m is produced.

In the course of sintering progressing from the upper layer to the lower layer of this Dwyroid type sintering machine, the lower layer of the raw material layer melts while receiving gravity due to the weight of the sinter cake after the melting and cooling of the upper layer. Therefore, the molten layer, which is a mixed layer of a solid and a liquid, is compressed, and the lower the layer, the higher the bulk density, so that the ventilation resistance increases sequentially. As a result, the amount of air sucked into the lower layer of the blended raw material is reduced, and the burning rate of the fuel (usually coke breeze) contained in the blended raw material is reduced, and the production amount is reduced.

In order to solve this problem, for example, Japanese Unexamined Patent Publication No.
As disclosed in Japanese Patent Application Publication No. 1-170522, a binder for improving the granulation property is added to a lower layer compounding raw material than an upper layer to increase the cold strength of pseudo particles of the lower layer compounding raw material, and further, the upper layer is coarsened. A method of suppressing the compression of the lower layer portion due to the load of the sinter cake and reducing the ventilation resistance to improve the productivity has been proposed.

In Japanese Patent Application Laid-Open No. 2-293586, a convex support is provided on the bottom surface of a sintered pallet and / or on the inner wall of the pallet to uniformly ignite the surface of the compounding raw material and to form the upper layer of the sinter cake. A method has been proposed in which a load is supported by a convex support to prevent an increase in bulk density of a lower layer portion.

[0006]

The above-mentioned (1) Japanese Patent Application Laid-Open No. 61-170522 and (2) Japanese Patent Application No. 2-293 are disclosed.
No. 586 has the following problems. The granulation strengthening of the lower layer material in the above (1) has a problem that the production cost is increased by newly adding a binder. In addition, the effect of suppressing the compression of the molten layer, which is a mixed layer of a solid and a liquid, although it basically has the effect of improving the cold strength of the compound raw material pseudo-particles or lowering the bulk density of the compound raw material in the cold state. Is less.

In the method of (2) for attaching a convex support, in the case of an existing sintering machine, the pallet is required to be remodeled significantly, so that the equipment cost is greatly increased. The cost of repairing the convex support increases. Due to the thermal stress during the sintering process, the convex support tends to be deformed and damaged, and the convex support is caught on the structure existing on the endless track of the sintering pallet, so that the sintering pallet cannot run. Equipment failures increase,
There is a problem that the equipment operation rate is reduced as compared with the case where there is no convex support. An object of the present invention is to reliably support the load of the sinter cake generated in the upper layer portion without having the above-mentioned problems, at a low cost, and without increasing equipment failure.

[0008]

The present invention for solving the above-mentioned problems consists of the following two means. In the present invention (1), bedding ore is charged on a sintering pallet to form a bedding layer, and a compounding raw material for sintering is charged on the bedding layer. When igniting and sintering ,
Palette convex increase thickness portion at a plurality of positions of the pallet width direction
A method for producing a sintered ore characterized in that the ore is continuously provided in a traveling direction .

According to the present invention (2), a cutting gate for charging a bedding ore on a sintered pallet to form a bedding layer can be moved up and down.
A sintering hopper equipped with a sintering machine, a charging device for charging the compounding raw material for sintering onto the bedsheet using a chute, and an ignition device for igniting a surface layer of the compounding raw material for sintering. In the machine, both the bedding ore cutting side wall surface and the cutting gate of the bedding ore hopper are placed at a plurality of locations in the pallet width direction.
A notch at the same position in the pallet width direction is provided for each of the two, and between the notch and the bottom end of the chute along or in the vicinity of the chute along the pallet advancing direction, the bedding mines cut out from the respective notches are provided. A sintering machine characterized in that a guide plate for covering an upper portion of the convex thickened portion is provided.

[0010]

The operation of the present invention will be described with reference to FIG. FIG.
(A), a convex thickened portion 5 formed as a pseudo structure by bedding ore is interposed in a lower portion of the blended raw material layer 3 on the bedding layer 4, and the surface of the blended raw material layer 3 is ignited. FIG. 4 is a cross-sectional view in the width direction of the sintered pallet after a lapse of a while.

As can be seen from this figure, a pseudo structure (hereinafter simply referred to as a pseudo structure) 5 in which a molten zone 2 formed in a blended raw material layer 3 is a convex thickened portion formed by bedding ore. When proceeding below the top, a sinter cake 1 is formed in the upper portion of the compounding raw material, which is cooled after the compounding material is melted to form an integrated mass. The entire load of the sinter cake 1 is supported by the pseudo structure 5, and no load is applied to the molten zone 2 and the blended raw material layer 3 below the sinter cake 1.

The bedding ores forming the pseudostructure 5 are not connected to each other, but are fixed by surrounding raw materials, and the crushing strength of the bedding particles is generally 100.
Since it is not less than kg / cm ² , it functions as a supporting structure that sufficiently supports the load of the sinter cake 1 in the upper layer. Therefore, the lower layer portion of the compounded raw material layer 3 is not compressed by the load of the upper layer portion sinter cake 1, and it is possible to suppress an increase in airflow resistance during firing and melting, and to prevent a decrease in coke combustion rate, thereby reducing production capacity. Can be improved.

On the other hand, as shown in FIG. 1 (b), when the pseudo structure 5 is not formed, there is no structure supporting the load of the upper layer sinter cake 1, so that the molten zone 2, the mixed raw material layer 3 is compressed under the load of the upper layer sinter cake 1, and the airflow resistance increases. For these reasons,
In the present invention (1), the blower suction negative pressure required for suction can be reduced by the amount corresponding to the reduction of the ventilation resistance, the power consumption can be reduced, and the sinter production cost can be significantly reduced.

FIG. 2 shows a comparison example 32 (in the state of FIG. 1 (b)) in which the pseudo structure 5 is not installed, and a pot in which the time course of the negative pressure of the blower suction in Example 31 of the present invention (1) was examined. The test result example is shown. The productivity was 32 T / D /
m ² , and the firing air volume is also substantially equal. As can be seen from FIG. 2, in Example 31 of the present invention (1), about 8 minutes after the surface of the compounding material layer 3 was ignited, the negative pressure of the blower suction began to gradually decrease, and was significantly higher than in Comparative Example 32. The effect of reducing the blower suction negative pressure is obtained. This is considered to be an effect of supporting the load of the sinter cake 1 which is a lump of the upper layer by the pseudo structure 5.

Here, since the pseudo structure 5 supporting the weight of the upper sinter cake 1 implemented in the present invention (1) is a bedding layer after sintering, deformation by thermal stress does not cause any problem. The sintering pallet 12 can be easily discharged from the sintering pallet 12, and there is no fear that the sintering pallet 12 may cause equipment failure such as being caught by an obstacle when the sintering pallet 12 is turned. Further, it is not necessary to modify the existing sintering pallet 12, and the repair cost of the convex support is unnecessary.

Further, as in the present invention (2), each of the notch portions is provided between the notch portion 8 of the floor hopper 6 and the lower end position of the chute 9 or in the vicinity thereof along the traveling direction of the sintering pallet 12. Since the guide plate 11 is provided to cover the upper part of the pseudo structure 5 formed by cutting out from the cutout 8, the pseudo structure 5 formed by cutting out from the cutout 8 is broken by the compounding material charged from the chute 9. Therefore, the pseudo structure 5 can be stably formed on the sintered pallet 12.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention (1) and (2) will be described with reference to FIGS. 3, 4 and 5. FIG. In this embodiment, the pallet width is 5 m, the pallet effective length is 120 m, and the production capacity is 36.
This is an example using a Dwyroid type sintering machine of T / D / m ² .

First, an embodiment of the present invention (1) will be described. A bedding ore having an average particle diameter of 20 mm in the bedding hopper 6 is cut out and charged on a sintering pallet 12 to form a 40 mm thick bedding layer 4 as shown in FIG. A pseudo-structure 5 having a trapezoidal cross section having a height of 300 mm, an upper surface width H _{1 of} 20 mm, and a lower surface width H _{2 of} 60 mm is continuously formed in the traveling direction of the sintered pallet 12. Thereafter, the raw materials (iron ore powder: 67%, serpentine powder: 2.2%, silica stone powder:
0.2%, limestone powder: 9.6%, quicklime powder: 0.6%,
Returned ore: 17.2%, coke breeze: 3.2%)
And it is charged on the pseudo structure 5.

That is, the bedding ore is charged in layers on the sintering pallet 12. At this time, the pseudo structure 5 which is a convex thickened portion of the bedding ore is moved in the width direction of the sintering pallet . To form two rows. Then, a compounding material is filled around and above the pseudo structure 5. On the other hand, in the comparative example, the bedding ore was charged at a thickness of 40 mm onto the sintering pallet 12 to form the bedding layer 4 without forming the pseudo structure 5, and the compounding raw material was added to the bedding layer 4. The top was charged in a uniform thickness.

Table 1 shows the operation results of this embodiment and the comparative example. As can be seen from Table 1, in this example, the productivity was improved to 1.09 times as compared with the comparative example. This is because the pseudo structure 5 bears the load of the sinter cake 1 which is a lump of an upper layer, and when the melting zone 2 is formed in the lower layer below the top of the pseudo structure 5, the melting point is reduced. It is presumed that the suppression of the compression of the band 2 provided the effect of improving the ventilation.

[0021]

[Table 1]

Next, an embodiment of the present invention (2) will be described. This example, as shown in FIGS. 3, 4 and 5, Oite the bottom of bedding hopper 6 in the pallet width direction 1400m
An inverted V-shaped notch 8 is provided at a pitch of m. Further, one end of the guide plate 11 having an inverted V-shaped cross section parallel to the traveling direction of the sintering pallet 12 is connected to the floor hopper 6.
Is fixed around the notch 8 and is cantilevered. The guide plates 11 are located between the notch 8 and the position below the lower end of the chute 9, and are arranged in two rows in the width direction of the sintered pallet 12. Further, the cutout gate 7 is provided with a rectangular cutout 13 so as not to hinder the guide plate 11.

The thickness of the bedding layer 4 formed on the sintering pallet 12 is controlled by raising and lowering the cutting gate 7 configured as described above to adjust the amount of bedding to be cut. The inverted V-shaped guide plate 11 has a length C1: 1000 mm, a height C2: 250 mm, and is installed at a height C3 from the bottom of the sintered pallet 12 of 300 mm, an installation pitch C4 of 1,400 mm. is there. However, any of these dimensions may be such as to maximize the air flow resistance reduction effect under operating conditions such as the size of the sintering machine, the size of the charging device, and the operating conditions such as the raw material brand and particle size distribution.

Next, the operation will be briefly described.
When the sintering pallet 12 starts moving, the cutting gate 7 provided on the floor hopper 6 configured as described above is raised,
The bedding ore in the bedding hopper 6 is cut out to a sintering pallet 12 to form the bedding layer 4 and the two rows of pseudo structures 5 described in the embodiment of the present invention (1).

Further, the compounding raw material is charged onto the guide plate 11 and the floor layer 4 through the chute 9. Then, as the sintering pallet 12 moves, the pseudo structure 5 formed in the guide plate 11 appears in the compounding material layer 3.
Thereafter, the surface of the compounding raw material layer 3 is ignited by the ignition furnace 10 to start sintering of the compounding raw material to produce the sinter cake 1.

[0026]

As described above, according to the present invention, the cost of equipment remodeling is lower than that of the conventional method, the cost of producing sinter can be greatly improved, the equipment failure is significantly reduced, and the operation rate is reduced. Improves productivity, and
It has a great effect such as a drastic reduction in maintenance costs.

[Brief description of the drawings]

FIGS. 1 (a) and 1 (b) are schematic views of a process of firing a compounding raw material.

FIG. 2 is a diagram showing a change in suction negative pressure of blowers according to an embodiment of the present invention (1) and a comparative example.

FIG. 3 is a perspective view showing an embodiment of the present invention (2).

FIG. 4 is a side view showing an embodiment of the present invention (2).

FIG. 5 is a schematic view of an embodiment of the present invention (1).

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 sinter cake 2 melting zone 3 compounding material layer 4 bedding layer 5 pseudo structure 6 bedding hopper 7 cutout gate 8 notch 9 chute 10 ignition furnace 11 guide plate 12 sintering pallet 13 notch 31 inventive example 32 comparison An example

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-211240 (JP, A) JP-A-61-174339 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C22B 1/00-61/00 F27B 21/10

Claims (2)

(57) [Claims] Claims: 1. A bedding bed is charged on a sintering pallet to form a bedding bed, and a compounding material for sintering is loaded on the bedding bed.
After that, when igniting and sintering the surface layer of the compounding raw material, the sintering is characterized in that convex thickened portions are continuously provided in the pallet advancing direction at a plurality of places in the pallet width direction of the floor layer. How to make ore. Wherein the bedding ore hopper the cutting gate for by charging the Yukashikiko on a sintered pallet to form a bedding layer equipped vertically movable, sintered onto the bedding layer a charging device for charging the use mixed material using a chute, in the sintering machine having an ignition device for igniting a surface layer of blended raw material for sintered, and bedding mineral cutting side wall of the Yukashikiko hopper Both sides of the cutting gate
At multiple locations in the width direction of the pallet
Notch is provided at the same position in the pallet width direction for both ,
A guide plate is provided between the notch and the lower end position of the chute or in the vicinity thereof along the pallet advancing direction to cover the upper part of the convex thickened portion of the bedding mined from each of the notches. A sintering machine.