JPH06200330A - Sintering method using scrap as raw material - Google Patents

Abstract

PURPOSE:To reduce the consumption of coke and to restrain the generation of CO2 and NO2 by exothermally oxidizing to melt-sinter the scrap having a specified value or less of the max. size. CONSTITUTION:Bedding ore 33 is charged on a fire grate of a pallet in 30mm. Thin piece iron scrap having the max. thickness of <=3mm and the longest side of <=50mm is sheered from a hopper 21, and 15% of the mixed binder having <=3mm grain diameter consisting of 33% powdery iron ore, 58% powdery lime stone, 0.5% powdery silica and 8.5% powdery coke, and 85% of the iron scrap as small pieces is discharged from a binder hopper 25. Water is added to and mixed with the binder by 12% using a mixer 10. Successively, the scrap raw material 22 prepared by mixing the binder with the thin piece iron scrap is charged to the pallet 12 through a chute 4 to form a packing layer 23 at 500mm thickness and heated with an ignition furnace 11, and while sucking the air downward, the thin piece iron scrap is melt-sintered. In comparison with the conventional method, as the consumption of the coke is little, 62% of CO2 and 60% of NO2 can be reduced.

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, which is a raw material for producing hot metal in a blast furnace or the like, from scrap.

[0002]

2. Description of the Related Art FIG. 5 shows an example of a schematic process of a conventional method for producing a sintered ore.

Ore hopper 9 is the main raw material, limestone 8 is the auxiliary raw material, limestone hopper 8 is the auxiliary raw material, coke hopper 6 is the coke which is the fuel, and return hopper 7 is the return mine. For example, 6.8% is added to perform humidity-controlled granulation to obtain a sintering raw material.

A sintering raw material 1 containing 3.8% of coke is once charged into a surge hopper 2, cut out from a drum feeder 3 and charged into a pallet 12 through a chute 4 to form a packing layer 5. In order to protect the grate (not shown) of the pallet 12, an agglomerated sinter of about 10 to 20 mm is charged as a bedding (not shown). The layer thickness of the packing layer 5 is 5
It is 50 mm.

The ignition furnace 1 is installed in the coke on the surface of the packed bed 5.
Ignition is performed at 1, and while sucking air downward, the coke added with 3.8% of the sintering raw material is burned, and the raw material is sequentially sintered from the upper layer to the lower layer by the heat of combustion.

There is also a method of using anthracite, which is cheaper than coke, as a substitute for coke. Alternatively, JP-A-61
Japanese Patent Laid-Open No. 99635 describes a method of drying coke and reducing the water content of the coke to reduce the amount of coke.

[0007]

Since the above-mentioned conventional method uses coke as a heat source, CO ₂ and NO ₂ are generated due to the combustion of coke, which is not preferable from the environmental point of view.

The method of using anthracite as a substitute for coke cannot suppress the generation of CO ₂ , has a small reserve, and has a problem that it is difficult to secure the amount. Further, the method described in Japanese Patent Laid-Open No. 61-99635 has a limit in reducing the amount of coke, so that the generation of CO ₂ and NO ₂ cannot be greatly suppressed.

The present invention solves the above problems, reduces the coke of the heat source, and reduces the CO ₂ and NO ₂ derived from the combustion of the coke.
The purpose is to suppress the occurrence of.

[0010]

The gist of the present invention is as follows.

In the downward suction type sintering machine, after the flaky iron scrap, the mixture of the flaky iron scrap with the solvent, or the mixture of the lump scrap with the solvent added is charged into a sintering pallet to form a packed bed. , A sintering method using scrap as a raw material, which comprises igniting and sintering a surface layer of a packed bed.

The maximum thickness of the flaky iron scrap is 3
mm, and the longest side is 50 mm or less. A sintering method using the scrap as a raw material.

The maximum thickness is 3 mm or less, and the longest side is 50
A sintering method using the scrap as a raw material, characterized in that 1 to 30% of the solvent is mixed with respect to the total weight of the flaky iron scrap having a size of mm or less and the solvent.

The maximum thickness is 5 mm or less, and the longest side is 15
A sintering method using the scrap as a raw material, characterized in that the solvent is mixed in an amount of more than 30% and 70% or less with respect to the total weight of the lump scrap of 0 mm or less and the solvent.

The thin piece iron scrap and the lump scrap refer to cut pieces of industrial waste such as food and drink cans, scrap car iron plates, waste electric appliances, and iron scraps generated in steelworks. The solvent is a mixture of iron ore powder, limestone powder, silica powder, and coke powder (hereinafter referred to as a binder), a maximum thickness of 1 mm or less, a scrap having a longest side of 20 mm or less (hereinafter referred to as a scrap chip), a binder. And a mixture of scrap chips (hereinafter referred to as a composite agent).

[0016]

In order to solve the above-mentioned problems, the present invention is to sinter the flaky iron scrap and the lump scrap by utilizing the oxidation heat of the flaky iron scrap in the sintered layer. Hereinafter, the present invention will be described in detail.

When the surface layer of the packed bed of flaky iron scrap, flaky iron scrap and solvent mixture, or lump scrap and solvent mixture is ignited, heat is generated due to the oxidation heat of the flaky iron scrap and solvent scrap chips and the combustion heat of solvent coke. The scrap melts. Further, when a solvent is added to the flaky iron scrap and sintered, the solvent plays a role of glue and the sintering can be easily performed.

The size of the flaky iron scrap has a thickness of 3 m.
It is preferable that the length is m or less and the longest side is 50 mm or less from the viewpoint of heat transfer, and it is obtained by cutting scrap. This flake iron scrap is only flake iron scrap, that is, flake iron scrap 1
After loading 00% into a sintering pallet to form a packed bed,
The surface layer of the packed bed can be ignited and sintered.

The particle size of the binder is preferably 3 mm or less. Three
This is because if it exceeds mm, heat is not transferred to the center of the grain, so that it is difficult to melt and does not serve as a paste.

The compounding ratio of the solvent (solvent / solvent + flakes scrap) depends on the size of the flakes scrap.

The maximum thickness of thin iron scrap is 3 mm or less,
The longest side of 50 mm or less is preferable from the viewpoint of heat transfer, and if it is more than 50 mm, sintering becomes unstable. The lower limit of the flaky iron scrap does not have to be limited, and the finer it is, the more preferable in terms of heat transfer and meltability.

When the amount of large flaky iron scrap having a maximum thickness of 3 mm and a longest side of 50 mm is large, heat transfer deteriorates and melting becomes uneven. Therefore, it is necessary to increase the solvent compounding ratio. Is preferably 1% or more and 30% or less. This is because if the blending ratio is less than 1%, the melting becomes insufficient, and if it exceeds 30%, the melting becomes excessive.

The maximum size of lump scrap is 5 m.
It is preferable that the length is m or less and the longest side is 150 mm or less in terms of heat transfer, and a large scrap is cut.

Since the lump scrap is large, the heat transfer is poor and the melting becomes non-uniform. Therefore, it is necessary to mix a large amount of the solvent and sinter, and the mixing ratio of the solvent varies depending on the size of the lump scrap. When the amount of large lump scraps with a maximum thickness of 5 mm and a longest side of 150 mm increases, heat transfer deteriorates,
Since the melting becomes non-uniform, it is necessary to increase the blending ratio of the solvent. The blending ratio of the solvent is preferably 30% or more and 70% or less. If the blending ratio is less than 30%, melting will be insufficient, resulting in 7
This is because if it exceeds 0%, the melting becomes excessive.

The lower limit of the size of the lump scrap does not have to be limited, and the smaller the size, the better in terms of heat transfer and melting property.

[0026]

The present invention will be described below with reference to preferred embodiments.

[0027]

Example 1 As shown in FIG. 1, a lump ore of 10 to 20 mm cut out from a lump ore hopper 31 was once charged into a lump ore surge hopper 32, and a lump ore of 30 mm was placed on a pallet grate (not shown). It was charged in a layer thickness to obtain a bedding 33.

A thin piece of iron scrap having a maximum thickness of 3 mm or less and a longest side of 30 mm or less is cut out from the thin piece iron scrap hopper 21, once charged in the surge hopper 2, and then cut out from the drum feeder 3 via the chute 4 to the pallet 1.
Then, the scrap filling layer 23 was formed to a thickness of 500 mm.

The flaky iron scrap in the surface layer of the scrap-filled layer 23 is heated in the ignition furnace 11, the flaky iron scrap is oxidized while sucking air downward, and the flaky iron scrap is sequentially melted from the upper layer to the lower layer by this oxidation heat. And sintered.

Since no coke is used, CO ₂ and NO ₂
Did not occur.

[0031]

Example 2 As shown in FIG. 2, a lump ore of 10 to 20 mm cut out from a lump ore hopper 31 was once charged into a lump ore surge hopper 32, and was placed on a pallet grate (not shown) of 30 mm. It was charged in a layer thickness to obtain a bedding 33.

A thin iron scrap having a maximum thickness of 3 mm or less and a longest side of 50 mm or less is cut out from the thin iron scrap hopper 21 and a binder having a particle size of 3 mm or less is cut out from a binder hopper 25, and a mixer 10 mixes the water with a water content of 12%.
Add and mix.

The binder is 33% iron ore powder and 58 limestone powder.
%, Powder silica 0.5%, powder coke 8.5%. Also, the compounding ratio of the binder is 15%, and the remaining 85
% Is scrap iron scrap.

The scrap raw material 22 in which the binder and the flaky iron scrap are mixed is once charged into the surge hopper 2, cut out from the drum feeder 3 and charged into the pallet 12 through the chute 4 to form the scrap packing layer 23 of 500 mm. .

The flaky iron scrap in the surface layer portion of the scrap packed bed is heated in the ignition furnace 11, and while sucking air downward, the flaky iron scrap is sequentially heated from the upper layer to the lower layer by the oxidation heat of the flaky iron scrap and the combustion heat of the coke of the binder. The scrap was melted and sintered.

Since the coke was mixed with the binder in a small amount, CO ₂ generation was reduced by 62% and NO ₂ generation was reduced by 60% as compared with the conventional method shown in FIG.

[0037]

[Embodiment 3] As shown in FIG. 2, a lump ore of 10 to 20 mm cut out from the lump ore hopper 31 is once charged into the lump ore surge hopper 32, and 30 m above the pallet grate.
It was charged in a layer thickness of m to obtain a bedding 33.

A flaky iron scrap having a maximum thickness of 3 mm or less and a longest side of 30 mm or less was cut out from the flaky iron scrap hopper 21 and solvent scrap chips from a scrap chip hopper 24 and mixed by a mixer 10. The scrap chip composition ratio is 30%, and the remaining 70% is flaky iron scrap.

The flaky iron scrap mixed with scrap chips was once charged into the surge hopper 2, cut out from the drum feeder 3 and charged into the pallet 12 through the chute 4, and a scrap filling layer 23 having a thickness of 500 mm was formed.

The scrap chips and the flaky iron scraps in the surface layer of the scrap-filled layer are heated in the ignition furnace 11 and the air is sucked downward while the scrap chips and the flaky iron scraps are oxidized by the heat of oxidation of the scrap scraps from the upper layer to the lower layer in order. The iron scrap was melted and sintered.

Since no coke is used, CO ₂ and NO ₂
Was not observed.

[0042]

[Embodiment 4] As shown in FIG. 2, a lump ore of 10 to 20 mm cut out from the lump ore hopper 31 is once charged into the lump ore surge hopper 32, and 30 m above the grate of the pallet.
It was charged in a layer thickness of m to obtain a bedding 33.

A thin iron scrap having a maximum thickness of 3 mm or less and a longest side of 50 mm or less is cut out from the thin iron scrap hopper 21, a binder having a grain size of 3 mm or less is cut out from a binder hopper 25, and scrap chips are cut out from a scrap chip hopper 24, and the mixer 10 is used. Then, 12% of water was added to the binder and mixed.

The binder is 31% of fine ore, 56% of fine limestone,
It was a mixture of powder coke 13%. The binder compounding ratio is 10%, the scrap chip compounding ratio is 15%, and the remaining 75% is flaky iron scrap.

The scrap raw material 22 mixed with the composite agent was once charged into the surge hopper 2 and charged from the drum feeder 3 through the chute 4 into the pallet 12 to form a scrap filling layer 23 of 500 mm.

The surface layer portion of the packed bed 23 was heated in the ignition furnace 11, and while sucking air downward, the flaky iron scrap was sequentially melted and sintered from the upper layer to the lower layer.

Since coke was mixed with the binder in a small amount, CO ₂ generation was reduced by 61% and NO ₂ generation was reduced by 58% as compared with the conventional method shown in FIG.

[0048]

[Embodiment 5] As shown in FIG. 3, a lump ore of 10 to 20 mm cut out from a lump ore hopper 31 is once charged into a lump ore surge hopper 32, and a lump ore of 30 mm is put on a pallet grate (not shown). It was charged in a layer thickness to obtain a bedding 33.

A lump scrap having a maximum thickness of 5 mm or less and a longest side of 150 mm or less is cut out from the lump scrap hopper 26, and a binder having a particle size of 3 mm or less is cut out from the binder hopper 25, and 12% of water is added to the binder by the mixer 10. Mixed.

The binder is 34% of fine ore, 60% of fine limestone,
A mixture of powder silica 0.5% and powder coke 5.5% was prepared.
The compounding ratio of the binder is 40%, and the remaining 60% is lump scrap.

The scrap raw material 22 mixed with the binder was once charged into the surge hopper 2, cut out from the drum feeder 3 and charged into the pallet 12 through the chute 4, and a scrap packing layer 23 having a thickness of 530 mm was formed. The packed layer 23 having a layer thickness of 530 mm was compressed by 30 mm by the compression roller 29 to have a layer thickness of 500 mm.

The surface layer portion of the packed bed is heated in the ignition furnace 11,
The lump scrap was oxidized while sucking air downward, and the lump scrap was sequentially melted and sintered from the upper layer to the lower layer by this oxidation heat and the combustion heat of the coke of the binder.

Since the coke was mixed with the binder in a small amount, CO ₂ generation was reduced by 40% and NO ₂ generation was reduced by 38% as compared with the conventional method shown in FIG.

[0054]

[Sixth Embodiment] As shown in FIG. 3, the lump ore of 10 to 20 mm cut out from the lump ore hopper 31 is once charged into the lump ore surge hopper 32, and 30 m above the grate of the pallet.
It was charged in a layer thickness of m to obtain a bedding 33.

A lump scrap having a maximum thickness of 5 mm or less and a maximum length of 150 mm or less is fed from the lump scrap hopper 26, and a scrap chip of a solvent is scrap chip hopper 24.
The mixture was cut out from each and mixed with the mixer 10.

The scrap chip composition ratio is 30%,
The remaining 70% is lump scrap.

A scrap raw material 22 mixed with scrap chips was once charged into the surge hopper 2 and then charged from the drum feeder 3 through the chute 4 into the pallet 12 to form a scrap packing layer 23 of 530 mm.
The compression roller 29 is used to set the filling layer 23 having a thickness of 530 mm to 3
It was compressed to 0 mm to have a layer thickness of 500 mm.

The surface layer portion of the packed bed is heated in the ignition furnace 11,
The lump scrap was oxidized while sucking air downward, and the lump scrap was sequentially melted and sintered from the upper layer to the lower layer by the heat of oxidation and the heat of oxidation of the scrap chips.

Since no coke is used, CO ₂ and NO ₂
Was not observed.

[0060]

[Embodiment 7] As shown in FIG. 4, a lump ore of 10 to 20 mm cut out from a lump ore hopper 31 is once charged into a lump ore surge hopper 32, and is placed on a pallet grate (not shown) of 30 mm. It was charged in a layer thickness to obtain a bedding 33.

Steel can scrap for food and drink was used as the lump scrap. From steel can scrap hopper 27
A binder having a particle size of 3 mm or less is cut out from the binder hopper 25, and scrap chips are scrap chip hopper 2
The steel can scrap was cut out from No. 4 and mixed with 12 mm of water added to the binder by the compression crushing machine 28.

The binder is 31% of fine ore, 56% of fine limestone,
It was a mixture of powder coke 13%. Also, the binder mixture ratio is 15%, and the scrap chip mixture ratio is 15%.
The remaining 70% is steel can scrap for food and drink as lump scrap.

A mixture of the compacted and crushed lump scrap and the composite agent was once charged into the surge hopper 2, cut out from the drum feeder 3 and charged into the pallet 12 through the chute 4 to form a scrap packing layer 23 of 550 mm. The compression roller 29 causes the filling layer 23 having a layer thickness of 550 mm to be 50 m.
m was compressed to a layer thickness of 500 mm.

The surface layer portion of the packed bed 23 was heated in the ignition furnace 11, and the lump scrap was sequentially melted and sintered from the upper layer to the lower layer while sucking air downward.

Since the coke was mixed with the binder in a small amount, CO ₂ generation was reduced by 48% and NO ₂ generation was reduced by 46% as compared with the conventional method shown in FIG.

[0066]

According to the present invention, coke can be reduced because the temperature of the sintered layer rises due to the oxidation heat of scrap. The reduction of coke reduces the generation of CO ₂ and NO ₂ . In addition, since it becomes a sinter with a high iron content, it has a secondary effect of improving the quality of the raw material for pig iron production.

[Brief description of drawings]

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

FIG. 2 is a diagram showing an example of the present invention.

FIG. 3 is a diagram showing an example of the present invention.

FIG. 4 is a diagram showing an example of the present invention.

FIG. 5 is a diagram showing a schematic process of a conventional method.

[Explanation of Codes] 1 Sintering raw material 2 Surge hopper 3 Drum feeder 4 Chute 5 Packing layer 6 Coke hopper 7 Return mining hopper 8 Limestone hopper 9 Ore hopper 10 Mixer 11 Ignition furnace 12 Pallet 21 Thin iron scrap hopper 22 Scrap raw material 23 Scrap Packed bed 24 Scrap chip hopper 25 Binder hopper 26 Lump scrap hopper 27 Steel can scrap hopper 28 Compression crusher 29 Compressing roller 31 Lump ore hopper 32 Lump ore surge hopper 33 Flooring

Claims (4)

[Claims] 1. In a downward suction type sintering machine, a scrap iron scrap, a mixture of a scrap iron scrap with a solvent, or a mixture of a scrap scrap with a solvent is charged into a sintering pallet to form a packed bed. And then igniting the surface layer of the packed bed to sinter, and a sintering method using scrap as a raw material. 2. The maximum thickness of the flaky iron scrap is 3 m.
The method of sintering using scrap as a raw material according to claim 1, wherein the length is 50 m or less and the longest side is 50 mm or less. 3. The maximum thickness is 3 mm or less and the longest side is 50 m.
The sintering method using scrap as a raw material according to claim 1, wherein 1 to 30% of the solvent is mixed with respect to the total weight of the flaky iron scrap of m or less and the solvent. 4. The maximum thickness is 5 mm or less, and the longest side is 150.
Solvent is added to the total weight of lump scrap less than mm and solvent
The sintering method using scrap as a raw material according to claim 1, characterized in that the mixture is more than 0% and 70% or less.