KR20100107773A - Method of producing sintered ore - Google Patents

Abstract

PURPOSE: A method of producing sintered ore is provided to improve the combustion efficiency by gradually controlling the addition time of sintering fuel in a step of preparing a combined material for sintering. CONSTITUTION: A method of producing sintered ore comprises steps of: preparing a combined material for sintering, loading a sintering material in which other materials are added in the combined material into a sintering machine carriage(70), and lighting to perform a sintering process. The combined material preparation step includes mixing a fuel for fine particle sintering with iron ore for first combination and adding a fuel for coarse particle sintering for second combination.

Description

Manufacturing method of sintered ore {METHOD OF PRODUCING SINTERED ORE}

The present invention relates to a method for producing sintered ore, in particular, by adding stepwise in the process of separating and mixing the sintered fuel to the sintered blended raw material to improve the combustion rate and combustion efficiency of the fuel to prevent the reduction of recovery while satisfying the strength of the sintered ore The present invention relates to a method for producing a sintered ore so as to produce a sintered ore of uniform quality.

Generally, sintered ore is semi-finished product which is charged into blast furnace.In iron ore sintering facilities such as steel mills, sintered raw material is supplied to the sintered raw material hopper by conveyor and the sintered raw material hopper which is supplied with this raw material is charged into the sintering machine to start the sintering process of the sintered raw material. Going through.

Usually, the charged shape of the sintered raw material supplied to the sintered raw material hopper is loaded into the sintering machine while maintaining the state as it is, and the charging state of the sintered raw material in the sintered raw material hopper is dependent on the flow of air required for combustion in the sintering process. It affects the sintering speed (productivity) and the sintered ore quality is an important factor affecting.

The particle size of the iron ore used as a conventional sintering raw material is about 8mm or less, and various subsidiary materials and solid coke and anthracite are mixed as fuel and loaded into the sintering machine.

The raw material charging device provided in the conventional sintering machine includes a storage tank located at the top of the sintering machine to store the charged raw materials, a drum feeder installed at the lower portion of the storage tank and rotated by a separate motor, and spacing of the drum feeder. It is composed of a plate-shaped gate that can be installed to control the rotational speed of the drum feeder and the interval of the gate to control the discharge of the compounding material in the storage tank, the discharged compounding material is moved downward along the inclined plate and the slit bar as a dispersion device And it is charged to the sintering machine trolley.

The blended raw material charged to the sintering machine bogie is the solid fuel mixed in the blended raw material is burned from the upper layer to the lower layer by the air which is ignited from the surface by the ignition furnace and sucked downward. Partial melting of iron ore results in agglomeration.

Sintering productivity and sintered ore quality in the sintering process is greatly affected by the combustion efficiency of the coke and anthracite coal as fuel. In order to improve the sintering productivity, it is desirable to improve the air permeability of the sintered raw material layer formed on the sintering machine bogie so that the suction air flows smoothly. For this reason, the strength and recovery rate of the sintered ore decrease.

Conventionally, spontaneous ore, limestone, coke and anthracite are simultaneously mixed to form granules, but the time required for the complete combustion of anthracite has different characteristics. For the same size, dense anthracite coals have a slower burning time than powdered coke, and larger particles burn longer than smaller particles.

In the sintering process, anthracite coal has a longer combustion time than powdered coke, and consequently, delays the sintering time and may cause a decrease in sintering productivity.

In other words, the coke and anthracite have a significant difference in physical properties and the combustion speed thereof, and thus, when anthracite is mixed with coke, the sinterability may be adversely affected.

In the upper ignition downward suction sintering method, the heat of the upper part is transferred to the lower part, so that if the particle size of the blended material and the distribution of the solid fuel content are uniform, the upper layer lacks heat due to the inflow of cold air, while the lower layer loses heat generated from the upper layer. It is measured and caloric excess occurs.

As a result, the surface layer and the upper layer are incompletely determined to determine the sintered state. As a result, the strength of the sintered ore decreases and the quality variation occurs and the recovery rate is lowered. There is a problem that it is delayed and leads to deterioration of productivity.

The present invention has been proposed to solve the above problems in view of the above problems, the object of which is to add the compounding time of the sintering fuel during the sintering operation step by step to improve the combustion rate and combustion efficiency of the fuel, while satisfying the strength of the sintered ore It is to provide a method for producing a sintered ore that can improve the recovery rate.

The present invention for achieving the above object is a method of manufacturing a sintered ore to prepare a sintered blending raw material, and to charge the sintering raw material added to the sintering blending raw material into the sintering machine trolley, and then ignited to perform the sintering process As

The preparing of the blending raw material for sintering may include: first blending the fine sintering fuel with iron ore into a pseudo-particle mixture;

After the first compounding step of adding the granulated anthracite coal to the secondary compounding; characterized in that it comprises a.

The fine sintered fuel is coke having a particle size of 5 mm or less and anthracite coal having a particle size of less than 1 mm.

The granulated sintered fuel is anthracite coal having a particle size of 1 to 5 mm.

The present invention is to adjust the timing of the addition of the sintered fuel in the step of preparing a blended raw material for sintering step to shorten the combustion delay time and improve the combustion efficiency, according to the present invention, the combustion rate and By improving the combustion efficiency to meet the strength of the sintered ore while preventing the recovery rate has a useful effect of producing a sintered ore of uniform quality.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In the present invention, anthracite coal is added through a plurality of steps in the process of preparing a raw material for sintering by mixing powdered iron ore and auxiliary raw materials such as limestone and powdered coke and anthracite as sintering fuel. The granulated anthracite coal coated on the surface of this other raw material and secondaryly added is made to exist as free particles.

Referring to FIGS. 1 and 2, the method of manufacturing the sintered ore according to the present invention is a method of manufacturing the sintered ore by mixing raw materials such as iron ore, limestone, and the like in the primary mixer 22 to form pseudo particles. Thereafter, the primary mixer 22 has a step of preparing a blending raw material for sintering comprising the steps of secondary blending the pseudo-particles primary blended with the fuel for granulation sintering in the secondary mixer 24.

Here, the pseudo particle refers to a pseudo-granulated form in which fine powder is attached to nuclear particles (1 m / m or more).

At this time, the primary mixer 22 and the secondary mixer 24 are connected to a water supply pipe 25 so as to add water when mixing the raw materials, and the water through the nozzle 25a disposed at the end of the water supply pipe 25. The first and second mixers 22 and 24 are supplied into the interior.

Sintered ore manufacturing method comprising the step of preparing a compounding material for sintering, the primary and secondary mixers (22, 24), the sintered compounding materials supplied from the storage tank (10) located at the top of the sintering machine to store the charge material After mixing, the mixed sintering compound for sintering is stored in the feed feeder 40, and then the discharge rate is controlled by adjusting the rotational speed of the feed feeder 40 and the gap between the gates, As it moves downward, it is charged to the sintering machine cart 70.

The mixing process of the primary and secondary mixers 22 and 24 is as described in the step of preparing the raw material for sintering described above, wherein the fine sintering fuel added to the primary mixer 22 is contained in coke and anthracite coal. Only coke coal may be employed, or granular anthracite may be added together.

In this case, the powder coke, which is a fuel for fine sintering, has a size of 5 mm or less, and the fine anthracite coal preferably has a size of less than 1 mm.

At this time, the upper light is charged together from the upper light supply device 50 into the inside of the sintering machine trolley 70.

Subsequently, the blended raw material charged into the sintering machine bogie 70 is ignited from the surface by the ignition furnace 60 and sucked from the lower part of the sintering machine bogie 70 by the windbox 80 and the blower 90. By the solid fuel mixed in the blended raw material is combusted from the upper layer to the lower layer, by the heat of combustion of the solid fuel generated at this time, the secondary raw material and iron ore is partially dissolved, the mass is formed. Thereafter, the burned gas is discharged to the outside through the stack 100.

Therefore, when mixed by the primary mixer 22, as shown in Fig. 3a, coke or fine anthracite coal is coated on the surface of the iron ore, or coarse particle size of the coke becomes the nucleus of the pseudo particle, so that the anthracite or iron ore The powder is coated.

Meanwhile, the granulated sintered fuel added to the secondary mixer is introduced into the secondary mixer through the anthracite coal bin, and the granulated sintered fuel is anthracite coal having a particle size of 1 to 5 mm, and thus, as shown in FIG. The fine particles are coated on the surface of the primary blended pseudo particle, and the coarse anthracite coal penetrates into the space between the primary blended pseudo particles and exists as a single free particle.

Therefore, as shown in FIG. 4, in the process of supplying the anthracite coal as free particles among the sintering blending materials blended in the secondary mixer to be supplied into the feed feeder and charging into the sintering machine truck 70. It is relatively segregated in the upper part compared to coke.

This is because the proportion of free anthracite coal is lower than that of pseudoparticles.

In the sintering process of the sintering machine bogie, the anthracite coal of free particles is smoothly in contact with the intake air, and the combustion time of the anthracite coal disposed at the top and the combustion time of the pulverized coke disposed at the lower part are made at the same time. Therefore, the delay of sintering time can be eliminated, and the fall of intensity | strength and recovery rate of a sintered ore can be prevented.

Embodiments according to the present invention described above will be described with reference to Table 1 below.

     division Comparative example Example 1 Example 2 Example 3 Fuel addition ratio before the first formulation (wt%) cokes 100 50 50 50 hard coal 0 0 10 30 Fuel addition ratio after the first formulation (%) cokes 0 0 0 0 hard coal 0 50 40 20 Productivity (t / d / m2) 31.2 33.3 32.8 31.6 burglar(%) 76.5 78.5 78.3 77.5

In the step of preparing a blended raw material for sintering, 5 mm or less coke and 1 mm or less anthracite coal were mixed and assembled in the primary mixer 22, followed by mixing a total of 1 mm or more anthracite coal in a secondary mixer. In the case of, 3, productivity and strength were greatly improved compared with the comparative example.

In addition, it can be seen that productivity and strength are improved in the case of Example 2 having a small amount added in the primary blending step of the anthracite coal, or in the case of Example 1 which is not added at all compared to the comparative examples and Example 3.

Therefore, as in Example 1 or Example 2, it is desirable to reduce the amount of anthracite added in the first compounding step.

In the present invention, as the sintering delay time is reduced, the sintering productivity is greatly improved as well as the strength of the sintered ore. That is, through the present invention, by attaching the fine anthracite coal to the surface of the pseudo particle and having the granulated anthracite coal as free particles between the pseudo particles, the combustion time difference between the anthracite coal and the coke present in the pseudo particle is reduced and the combustion zone width is reduced. This is because dispersion of heat of sintering is prevented.

Therefore, the present invention can improve the quality of sintered ore and the sintering productivity through the improvement of combustion efficiency of anthracite coal in iron ore sintering .

1 is a schematic view showing the configuration of a method for manufacturing a sintered ore according to the present invention.

Figure 2 is a block diagram showing the first and second blending step of preparing a blending raw material for sintering of the present invention.

Figure 3a is a view showing a pseudo-particle structure by the sintered fuel and iron ore in the primary blending process, Figure 3b is a schematic diagram showing a state in which the anthracite coal and coke in the coarse particles in the free particle state after the secondary blending.

4 is a schematic diagram showing a distribution state of the sintered fuel according to the present invention.

Explanation of symbols on the main parts of the drawings

22: 1st mixer 24: 2nd mixer

30: anthracite bin 70: sintering machine bogie

Claims (3)

A method of manufacturing a sintered ore in which a raw material for sintering is prepared, a sintering raw material in which the remaining raw material is added to the sintering raw material is charged into a sintering machine truck, and then ignited to perform a sintering process. The preparing of the blending raw material for sintering may include: first blending the fine sintering fuel with iron ore so as to be pseudo-particles; And adding the fuel for granulation and sintering after the first mixing to mix the mixture in a second manner. 2. The method according to claim 1, The fine sintered fuel is a method for producing sintered ore, characterized in that the coke having a particle size of 5mm or less and anthracite coal having a particle size of less than 1mm. The method according to claim 1 or 2, The granulated fuel for sintering is a method for producing a sintered ore, characterized in that the anthracite coal having a particle size of 1 ~ 5mm.

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