JPH04240390A - Igniting method in sintered ore manufacturing process - Google Patents

Abstract

PURPOSE:To improve the yield and productivity by effecting sintering reaction in the surface layer of a material filling layer sufficiently in sintered ore manufacturing process. CONSTITUTION:In the igniting furnace 12 of a sintered ore manufacturing device, the surface layer 14 of sintering material layer is ignited by flame of combustible gas from an igniting burner 20 and air or oxygen enriched air. In this case, sintering promoting agent or carbon material and the sintering promoting agent are ejected into the flame together with air or oxygen enriched air.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to an ignition method in the manufacturing process of sintered ore, which is a raw material for making iron in a blast furnace, etc., that is, an ignition method that can greatly improve productivity in the sintered ore manufacturing process. Regarding.

0002

2. Description of the Related Art A conventional sintered ore production process is shown in FIG.

In the sinter production process, ore, which is the main raw material, is cut out from hopper 9, limestone, which is an auxiliary raw material, is cut out from hopper 8, return ore is cut out from hopper 7, and coke, which is fuel, is cut out from hopper 6. It is mixed, humidity controlled and granulated to become the raw material for sintering. The sintering raw material is transferred from the mixer 10 to the surge hopper 2 by a belt conveyor.
After being transported and stored, the raw material is cut out from the surge hopper 2 by the drum feeder 3 and loaded onto the pallet 11 via the chute 4 to form the raw material filling layer 5. In the sintered ore production process using iron ore as the main raw material, the thickness of the raw material filling layer 5 is usually about 600 mm.

The coke on the surface of the raw material packed bed 5 is ignited by a flame made of COG (coke oven gas) and air in an ignition furnace 12, and the coke in the raw material packed bed 5 is combusted while sucking air below the raw material packed bed 5. The heat causes the sintering reaction to proceed from the upper layer to the lower layer. In such a sintered ore manufacturing process, the raw material packed layer 5 surface layer 10
There is insufficient heat in the part with a thickness of about 0 mm, and the raw material is not sufficiently melted. For this reason, the strength of the sintered ore in the surface layer of the raw material packed bed 5 with a thickness of about 100 mm is particularly low, and the yield of product sintered ore with a particle size of 5 mm or more (hereinafter, the yield of product sintered ore is referred to as yield). ), which in turn reduces productivity.

[0005] As a method for solving this problem, there is a method disclosed, for example, in Japanese Patent Application Laid-open No. 185738/1983. In this method, pulverized coke is supplied from the burner of an ignition furnace to increase the amount of heat in the surface layer of the raw material packed bed for sintering, thereby increasing the strength of the sintered ore.

Furthermore, Japanese Patent Application Laid-Open No. 57-79130 discloses a technology for increasing the calorific value by supplying oxygen-enriched gas to the burner of an ignition furnace to improve the quality of sintered ore and improve the yield. is disclosed.

[0007]

[Problems to be Solved by the Invention] However, with these prior art techniques, although the temperature of the flame in the ignition furnace becomes high, simply increasing the temperature of the flame is not enough to melt the surface layer of the raw material packed bed. There are limitations, and the strength of the sintered ore in this part cannot be made sufficiently high, and the yield improvement effect is small, so these are not currently in practical use.

[0008] The present invention solves the problems in the prior art described above, and provides a method capable of achieving a sufficient sintering reaction in the surface layer of a raw material packed bed in a simple manner, improving yield and productivity. The purpose is to

[0009]

[Means for Solving the Problem] The gist of the present invention is to provide a sintering accelerator or carbonaceous material in a flame of combustible gas and air or oxygen-enriched air from an ignition burner in an ignition furnace of a sintered ore manufacturing apparatus. and an ignition method in a sintered ore production process characterized by igniting a sintering raw material layer while blowing out a sintering accelerator together with air or oxygen-enriched air.

0010

[Operation] The present invention will be explained in detail below.

When the raw material packed bed is ignited in the ignition furnace, the surface layer of the raw material packed bed is It is possible to accelerate the melting of the sintered ore and increase the amount of molten material, thereby increasing the strength of the sintered ore and improving the yield.

As the sintering accelerator, quicklime, limestone, serpentine, blast furnace slag, blast furnace ash, sinter factory dust and steelmaking slag can be used, but slag-forming substances containing CaO and MgO or iron content can be used. It is preferable to use powdered iron ore containing iron ore, and also mixtures thereof.

In the ignition furnace, combustible gas such as C
A flame is obtained with OG and air or oxygen-enriched air. To supply the sintering accelerator to the surface layer of the raw material packed bed, the sintering accelerator is added to air or oxygen-enriched air, and the sintering accelerator is heated or melted as the combustible gas burns, and the sintering accelerator is heated and melted together with the flame. Spray on the surface layer of the raw material packed bed. When a sintering accelerator is added to air or oxygen-enriched air, and a carbonaceous material is further added, the combustion flame of the flammable gas becomes high temperature, making it even more effective.

When a mixture of a slag-forming substance and iron ore powder is used as a sintering accelerator, the mixing ratio ranges from 1 part of the slag-forming material to 9 parts of the iron ore powder to 4 parts of the slag-forming material and 6 parts of the iron ore powder. shall be. This range is the low melting point region.

[0015] The particle size of the sintering accelerator is 1 mm or less. This is because the purpose of the present invention is to increase the amount of melting in the surface layer of the raw material packed layer and to sufficiently advance sintering. This is because it is necessary to maintain the state of If the sintering accelerator has coarse particles, it will not melt due to insufficient heat, so the particle size of the sintering accelerator is at most 1 mm.

The amount of the sintering accelerator to be supplied is an amount corresponding to 0.5 to 3.3% of the total thickness of the raw material packed layer. If the total thickness of the raw material filling layer is 600 mm, 3 mm at 0.5%,
It is 20 mm at 3.3%. Therefore, in a normal sintered ore production process using iron ore as the main raw material, the amount of sintering accelerator supplied is an amount corresponding to a layer thickness of 3 to 20 mm. 3
If the supply amount is less than mm, the amount of melting required to sufficiently progress the sintering of the surface layer of the raw material packed bed will not be achieved. If the supply amount exceeds 20 mm, the amount of heat will be insufficient, and the sintering accelerator will not be able to reach the surface layer of the raw material packed bed in a state immediately before melting.

Next, the degree of oxygen enrichment of the air and the amount of coke added to the air or oxygen-enriched air when burning combustible gas are determined when the flame temperature in the ignition furnace is 1300°C.
The temperature should not exceed ℃. Increasing the amount of oxygen and coke supplied to the burner increases the flame temperature, and the higher the flame temperature, the higher the yield of the product sinter. However, when the flame temperature exceeds 1300° C., wear and tear on the ignition furnace equipment becomes significant.

FIG. 2 shows an example of an ignition burner embodying the present invention.
Shown below.

The sintering accelerator jetting nozzle 21 transports the sintering accelerator or the sintering accelerator and carbon material supplied from the sintering accelerator supply port 26 using air supplied from the air pipe 27 as a carrier gas. and inject it into the combustion flame of flammable gas. The combustion nozzle 22 is connected to a valve 28 in a fuel gas pipe 24.
Oxygen or oxygen-enriched air supplied from the oxygen gas pipe 25 is ejected through the gas pipe 25 to form a flame at its outlet. The sintering accelerator injected from the sintering accelerator jetting nozzle 21 is heated and melted in the flame, and is sprayed together with the flame onto the surface layer of the raw material packed bed. When the carbonaceous material is injected into the flame together with the sintering accelerator, the carbonaceous material burns in the flame and releases heat. When the flame is blown onto the surface layer of the raw material packed bed,
The coke mixed in the raw material packed bed is ignited, and sintering progresses from the upper layer to the lower layer due to the combustion heat generated. As the sintering progresses, the sintering accelerator is further melted by the combustion heat of the coke and is sintered. In this way, the raw material in the surface layer of the raw material packed bed is also sufficiently sintered, and sintered ore with high strength can be obtained.

[0020]

[Example] Example 1 FIG. 1 shows one embodiment of the present invention.

The surface layer 14 of the raw material filling layer 5 having a layer thickness of 600 mm, which was formed on a sintered pallet in the same manner as in the conventional sinter production process, was ignited by the ignition burner 20 of the ignition furnace 12. Table 1 shows the ignition conditions at this time.

[0022] Sintering accelerators include quicklime, limestone, serpentine,
One or a combination of blast furnace slag, blast furnace ash, sinter factory dust, steelmaking slag, and fine iron ore was used. The basic idea of the combination was to create a two-part mixture of quicklime, limestone, serpentine, etc. as a melting agent and powdered iron ore as an iron component.

As is clear from Table 1, the productivity was 31t/d/m2 in the conventional sintered ore manufacturing process.
Productivity has been greatly improved to 7.6 to 38.9 t/d/m2.

Example 2 Table 2 shows the ignition conditions in Example 2.

In this example, in addition to the sintering accelerator, one or a combination of quicklime, limestone, serpentine, blast furnace slag, steelmaking slag, and powdered iron ore, a carbonaceous material, in this case coke powder, is added. The mixture was injected into the flame of an ignition burner. In addition to coke, coal materials include coal powder and char. Further, the basic concept of the combination of sintering accelerators is the same as in Example 1.

As is clear from Table 2, the productivity was 31t/d/m2 in the conventional sinter production process, but
Productivity has greatly improved from 8.0 to 40.9 t/d/m2.

Example 3 Table 3 shows the ignition conditions in Example 3.

In this embodiment, the air supplied to the combustion nozzle 22 is enriched with oxygen. The basic concept of the sintering accelerator and the combination thereof is the same as in Example 1.

As is clear from Table 3, the productivity in the conventional sintered ore manufacturing process was 31t/d/m2;
The productivity has been greatly improved to 9.0 to 41.9 t/d/m2.

Example 4 Table 4 shows the ignition conditions in Example 4.

In this embodiment, coke is added to the sintering accelerator, and the air supplied to the combustion nozzle 22 is enriched with oxygen. The basic concept of the sintering accelerator and the combination thereof is the same as in Example 2.

As is clear from Table 4, the productivity in the conventional sintered ore manufacturing process was 31t/d/m2, while the productivity was 4.
Productivity has greatly improved from 2.0 to 45.9 t/d/m2.

[0033]

[Table 1]

[0034]

[Table 2]

[0035]

[Table 3]

[0036]

[Table 4]

[0037]

Effects of the Invention According to the present invention, it is possible to achieve a sufficient sintering reaction in the surface layer of the sintered raw material packed bed using a simple method, and to produce high-strength sintered ore stably and with high productivity. can be manufactured.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of a sintering process for implementing the present invention.

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

FIG. 3 is a diagram showing an example of a conventional sintering process.

[Explanation of symbols]

1 Sintering raw material 2 Surge hopper 3 Drum feeder 4 Shoot 5 Raw material packed bed 6 Hopper 7 Hopper 8 Hopper 9 Hopper 10 Mixer 11 Palette 12 Ignition furnace 13 Sintered layer 14 Surface layer part 20 Ignition burner 21 Sintering accelerator jet nozzle 22 Combustion nozzle 24 Fuel gas pipe 25 Oxygen gas pipe 26 Sintering accelerator supply port 27 Air pipe 28 Valve

Claims (2)

[Claims] Claim 1: In an ignition furnace of a sintered ore manufacturing equipment, sintering is performed while spouting a sintering accelerator into a flame of flammable gas and air or oxygen-enriched air from an ignition burner together with air or oxygen-enriched air. An ignition method in a sinter production process characterized by igniting a raw material layer. [Claim 2] In an ignition furnace of a sintered ore manufacturing device, carbonaceous material and a sintering accelerator are ejected together with air or oxygen-enriched air into a flame of combustible gas and air or oxygen-enriched air from an ignition burner. An ignition method in a sintered ore production process characterized by igniting a sintered raw material layer while