JPH06129776A - Manufacturing method of sintered ore and pallet for the manufacturing of sintered ore - Google Patents

Abstract

PURPOSE:To make ventilation uniform in a widthwise direction of a pallet to improve the yield by reducing a porocity of a pallet bottom portion inside of a pallet side wall in a sintering machine as it goes toward the pallet side wall and/or reducing a porocity of the pallet bottom portion on opposite sides of a stand as it goes toward the stand. CONSTITUTION:A fire grate 4a, which is the first one from a pallet side wall 2, has a width 3.4 times as that of a conventional fire grate 3. Fire grates inclusive of the fire grate 4a, a fire grate 4f which is the sixth one from the pallet side wall 2, and intermediate fire grates have a width incrementally smaller by 0.4 times the width of the first fire grate 4a as they go near a center of a pallet 1. A gap between the respective fire grates 4a to 4f has the same magnitude as that of the conventional fire grate 3, so that as it goes toward the pallet side wall 2, a rate of gap per unit area becomes small. Accordingly, a suction force on the pallet 1 in a downward direction becomes small as it goes toward the pallet side wall 2, and so ventilation near the central portion of the pallet 1 and the pallet side wall 2 is made uniform. As a result, sintering speeds are made uniform to improve yield.

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 ore used as a raw material for pig iron production in a blast furnace or the like and a sinter ore production pallet used therefor.

[0002]

2. Description of the Related Art A conventional sinter production process is shown in FIG. 4 and a sinter pallet 1 is shown in FIG.

In FIG. 4, ore as a main raw material for producing a sintered ore is carried from a yard to an ore hopper 14, limestone as a sub raw material is carried to a hopper 12, and coke as fuel is carried to a hopper 11. Ore, limestone, and coke are cut from the hopper, and with the return ore cut from the return hopper 13,
The material is conditioned and granulated by the mixer 15 and used as a raw material. The granulated raw material 6 is conveyed to a surge hopper 7 and stored, then cut out from a drum feeder 8 and pallet 1 through a chute 9.
Then, the filling layer 10 is formed. In the case of a sintering process using iron ore as the main raw material, the thickness of the raw material packed layer is usually 600.
It is about mm. Ignition furnace 1 on the coke on the surface of the packed bed
In step 6, the coke in the upper part of the packed bed is ignited by the heat of combustion of gas, the coke is burned while sucking air downward, and the raw material is sequentially sintered from the upper layer to the lower layer by this combustion heat.

A conventional pallet of this kind is shown in FIG. The grate 3 near the pallet side wall of this pallet is shown enlarged in FIG. The size of the grate is constant and the gap of the grate is also constant. Therefore, since the porosity per unit area is also constant, the downward suction force is also constant.

As shown in FIGS. 5 and 6, a pallet is filled with a grate, and the raw material filling layer 10 is ventilated from the gap of the grate by a suction force from below.

According to this conventional pallet, the packing density of the packing layer near the pallet side wall 2 becomes small, and due to the shrinkage due to the progress of sintering, the gap between the pallet side wall 2 and the packing layer becomes large. However, there is a problem that the ventilation becomes excessive and the sintering becomes too fast, which reduces the strength of the sintering and lowers the yield (the yield of the product sintered ore of 5 mm or more).

As a method for solving such a problem,
A method of increasing the density by pressing the surface layer of the packing layer near the pallet side wall from above to reduce ventilation, or JP-A-58-58
As proposed in 31040, there is a method of providing a partition plate with a packed bed near the pallet side wall and charging return ore between the pallet side wall and the partition plate to reduce ventilation near the pallet side wall. is there. However, it cannot be said that these methods have been sufficiently solved, and at present, they have not been put to practical use.

Further, the present inventors have found that the lower layer of the raw material filling layer is a sintered lump integrated with the sintered pallet after sintering (hereinafter, a sintered lump integrated with the sintered pallet after sintering is sintered). It is compressed by the weight of (cake) and has a high bulk density, resulting in poor ventilation, which reduces the amount of air sucked into the packed bed and the coke burning rate, which reduces productivity. As a solution, a sintering cake supporting sintering method is disclosed in Japanese Patent Application Laid-Open No. 4-16 as a technology for improving the productivity by eliminating the load of the sintering cake and improving the ventilation of the sintered layer.
8234 publication. This sintering cake supporting sintering method, as in the conventional method, has excessive ventilation at the boundary between the side wall of the stand supporting the sintering cake and the packed bed, and the sintering becomes too fast, the sintering strength becomes small, and the yield Has left the problem of falling.

[0009]

In the sintering according to the prior art, the pallet side wall and the adjacent packed bed, or the sintering cake supporting sintering method causes excessive ventilation at the boundary between the stand side wall surface and the packed bed, and the sintering is too early. However, there is a problem that the strength of sintering becomes small and the yield decreases.

[0010]

[Means for Solving the Problems]

A first aspect of the present invention for solving the above problems is to reduce the opening rate of the pallet bottom portion inside the side wall of the sintering pallet of the lower suction type sintering machine toward the side wall and / or to provide a pallet with a stand. In the method for producing a sinter, the raw material is charged into a pallet, and the pallet bottom opening rate on both sides of the pallet is made smaller toward the pallet, and the pallet is sintered.

According to the second aspect of the present invention, the opening rate of the bottom portion of the pallet inside the side wall of the sintering pallet of the lower suction type sintering machine becomes smaller toward the side wall, and / or the opening rate of the bottom portion of the pallet provided with a stand. The pallet for sinter ore production is characterized in that the pallet is made smaller toward both sides of the pallet stand.

[0013]

The opening rate of the pallet bottom is adjusted in the center of the pallet and in the vicinity of the side wall of the pallet, so that the ventilation in the vicinity of the pallet is made uniform and the sintering is performed in a state where the sintering speed is made uniform.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The features of the present invention will be described in detail below with reference to FIGS.
The sintering process is the same as the conventional method shown in FIG. 4, and the layer thickness is 600 mm.

Embodiment 1 As an embodiment of the present invention, the vicinity of the side wall of a pallet is shown in FIG.
The width of the first grate 4a closest to the side wall of the pallet is 3.4 times that of the conventional grate 3 and the first grate 4a to 6
The grate up to the 4th grate 4f is reduced by 0.4 times from the magnification of the 1st grate 4a as it gets closer to the center of the pallet. Therefore, the magnification of the grate is 3.0 for the second grate 4b, 2.6 for the third grate 4c,
The fourth grate 4d is 2.2, the fifth grate 4e is 1.8, and the sixth grate 4f is 1.4.

Since the gap of the grate is the same as that of the conventional grate 3, the porosity per unit area becomes smaller as it gets closer to the side wall of the pallet. Therefore, the closer the pallet is to the side wall of the pallet, the smaller the suction force to the lower side.As a result, the problem that the ventilation becomes excessive near the pallet side wall and the sintering becomes too fast is solved. As a result, the sintering rate becomes uniform, the strength increases, and the yield improves.

Compared with the yield of the sintering method of 75.2% in the conventional sintering pallet, the yield of the sintering method of the sintering pallet according to the present invention was improved by 78.4% and 3.2%.

Example 2 The sintering process is the same as the conventional method shown in FIG. 4, and the layer thickness is 600 mm. As another embodiment of the present invention, a pallet 1 having a stand 5a and a stand 5b installed is shown in FIG.

FIG. 3 shows the installation condition of the first grate 4a, the second grate 4b, the third grate 4c, and the fourth grate 4d around the stands 5a and 5b. The width of the first grate 4a closest to the side wall of the stand is 2.2 times the width of the conventional grate 3 and the grates from the first grate 4a to the fourth grate 4d move away from the stand. It is reduced by 0.3 times from the magnification of the second grate 4a. Therefore, the magnification of the grate is 1.9 for the second grate 4b and 1.6 for the third grate 4c,
The fourth grate 4d is 1.3.

Since the gap of the grate is the same as that of the conventional type grate 3, the porosity per unit area becomes smaller as it approaches the side wall of the stand. For this reason, the closer the pallet is to the side wall of the stand, the smaller the suction force downwards, and as a result, the problem of excessive ventilation and the excessively rapid sintering near the side wall of the stand is solved. Ventilation becomes uniform, and as a result, the sintering rate becomes uniform, the strength increases, and the yield improves.

Compared with the yield of the sintering method of 75.2% in the conventional sintering pallet, the yield of the sintering method of the sintering pallet according to the present invention was improved by 81.6% and 6.4%.

Example 3 The sintering process is the same as the conventional method shown in FIG. 4, and the layer thickness is 600 mm. As another embodiment of the present invention, the vicinity of the side wall of the pallet is shown in FIG. 1, and the installation situation of the stands 5a and 5b is shown in FIG. The stand 5a and the stand 5 are shown in FIG.
the first grate 4a around b, the second grate 4b,
The installation situation of the third grate 4c and the fourth grate 4d is shown.

In FIG. 1, the one closest to the side wall of the pallet
The width of the fourth grate 4a is 3.4 times that of the conventional type grate 3 and the magnifications of the first grate 4a to the sixth grate 4f are 0.
It is made four times smaller. Therefore, the magnification of the grate in the present invention is 3.0 for the second grate 4b, 2.6 for the third grate 4c, 2.2 for the fourth grate 4d, and 1 for the fifth grate 4e. 8th and 6th grate 4f is 1.4
Is.

Since the gap of the grate in the present invention is the same as that of the conventional grate 3, the porosity per unit area becomes smaller as it gets closer to the side wall of the pallet. Therefore, the closer the pallet in the present invention is to the side wall of the pallet, the smaller the downward suction force becomes, and as a result, the problem that the ventilation becomes excessive near the side wall of the pallet and the sintering becomes too fast is solved. The near sintering rate became uniform.

On the other hand, in FIG. 3, the width of the first grate 4a closest to the side wall of the stand is set to be 2.2 times the width of the conventional grate 3 and the grate from the first grate 4a to the fourth grate 4d is set. As they move away from the stand, the magnification is reduced by 0.3. Therefore, the magnification of the grate is 1.9 for the second grate 4b, 1.6 for the third grate 4c, and 1.3 for the fourth grate 4d.

Since the gap of the grate is the same as that of the conventional type grate 3, the porosity per unit area becomes smaller as it gets closer to the side wall of the stand. For this reason, the closer the pallet is to the side wall of the stand, the smaller the suction force downwards, and as a result, the problem of excessive ventilation and the excessively rapid sintering near the side wall of the stand is solved. Ventilation was made uniform, and as a result, the sintering rate was made uniform, and the strength of the sinter near the side wall of the pallet and the sinter near the side wall of the stand increased, and the yield improved.

The yield of the sintering method of the sintering pallet according to the present invention was improved by 83.0% and 7.8% as compared with the yield of the sintering method of 75.2% in the conventional sintering pallet.

In the first, second and third embodiments, the width of the grate is increased to change the porosity per unit area, but the porosity per unit area may be changed depending on the gap of the grate. .

[0029]

As described above, according to the present invention, the ventilation in the width direction of the sintering pallet becomes uniform, and the ventilation in the width direction of the sintering pallet provided with the sinter cake support stand becomes uniform so that all layers are formed. The yield is improved because the strength of the sintered ore is improved by uniformly sintering over the entire length. It was improved by 3.2% to 7.8% as compared with the conventional method.

[Brief description of drawings]

FIG. 1 is a partially enlarged perspective view showing a state of a pallet according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing a pallet in a second embodiment of the present invention.

FIG. 3 is a partially enlarged perspective view showing a state near a stand of the pallet of the present invention in FIG.

FIG. 4 is a diagram showing a conventional sintering process.

FIG. 5 is a diagram showing a state of a conventional pallet.

FIG. 6 is a partially enlarged view of the vicinity of the side wall of the conventional pallet of FIG.

[Explanation of symbols]

 1 Pallet 2 Pallet Side Wall 3 Conventional Grate 4a Grate 1 4b Grate 2 4c Grate 3 4d Grate 4 4e Grate 5 4f Grate 6 5a, 5b Stand 6 Sintering Raw Material 7 Surge Hopper 8 Drum Feeder 9 Chute 10 Raw material packed bed 11 Coke hopper 12 Limestone hopper 13 Return ore hopper 14 Ore hopper 15 Mixer 16 Ignition furnace

Claims (2)

[Claims] 1. A pallet bottom opening rate inside a side wall of a sintering pallet of a lower suction type sintering machine becomes smaller as it approaches the side wall,
And / or a method for producing a sintered ore, comprising charging a raw material into a pallet having a pallet bottom opening rate on both sides of the pallet provided with a stand and making the pallet bottom opening rate smaller toward the stand, and sintering. 2. The pallet bottom opening rate inside the side wall of the sintering pallet of the lower suction type sintering machine is decreased as it approaches the side wall,
And / or a pallet for sinter ore production, characterized in that the opening rate of the bottom of the pallet provided with a stand is decreased toward the both sides of the stand of the pallet.