KR101908482B1 - Method of sintered ore - Google Patents

Abstract

The present invention relates to a method of producing sintered ores, comprising the steps of combining a first compounding material containing first iron ore, an additive and a fuel to form a first granulated product; Forming and crushing a second blend material including a second iron ore and a subsidiary material to produce a second blend; And charging the first granulation product and the second granulation product into a sintering bogie, wherein air permeability in the raw material layer can be ensured and the amount of heat can be controlled, thereby improving sintering productivity and quality.

Description

TECHNICAL FIELD The present invention relates to a method of producing sintered ores,

The present invention relates to a method for producing sintered ores, and more particularly, to a method for producing sintered ores that can improve the quality and productivity of sintered ores.

Dewight-Lyoid (hereinafter referred to as "DL ") type sintering process capable of mass production is mainly used for the sintered ores manufacturing process which is manufactured to a size suitable for use in a furnace by sintering fine iron ores. In this type of DL sintering process, mixing and humidity (raw material weight ratio of about 7 ~ 8%) is put into drums mixer by adding minute iron ore, subsidiary raw material and fuel (minute coke and anthracite coal) to make pore- To a predetermined height. Then, after the surface is ignited by the ignition furnace, firing of the sintering material is proceeded while forced air is sucked from below, and sintered ores are produced. After sintering, the sintered ores are cooled in a cooler through a crusher in the light pipe, and classified into granules having a size of 5 to 50 mm which is easy to charge and react in the blast furnace and are transferred to the blast furnace.

On the other hand, as the quality of high-grade iron ores having high iron content and relatively large grain size is reduced in the production of sinter ores, the amount of low-grade iron ores having a high fractional proportion of 0.15 mm or less is gradually increasing. However, in order to improve productivity by advancing the sintering reaction efficiently in the DL type sintering process and to produce sintered ores with good quality, it is important to ensure air permeability so that a proper amount of air can flow through the layer. Therefore, it is necessary to minimize the differentiating ratio among raw materials for sintering. When using iron ores having a very high fractional proportion, such as fine iron ores produced through the process of beneficiation of iron ore, they should be prepared as granules through separate pretreatment and used as raw materials for sintering .

In addition to the particle size distribution of the granules in the sintering process, the strength of the granules greatly affects the air permeability of the sintered layer. Accordingly, there is a demand for a method capable of manufacturing the assembly so as to have strength enough to withstand mechanical and thermal shocks to be received during transportation, charging, and firing.

In the sintering process, the sintered ores are produced by burning from the upper layer portion to the lower layer portion of the raw material layer. The amount of heat accumulated in the lower layer portion of the raw material layer is accumulated to generate an excess melted material. This phenomenon hinders the air permeability in the raw material layer, so that the sintering does not occur uniformly and the sintering light increases. This phenomenon appears to be more serious in the high-back operation where the post-sintering temperature is increased to improve the sintering productivity.

KR 1299376 B KR 1449456 B

The present invention provides a method for producing sintered ores that can uniformly maintain air permeability and heat quantity in a raw material layer.

The present invention provides a method for manufacturing sintered ores that can improve productivity and reduce manufacturing costs.

A sintered light producing method according to an embodiment of the present invention is a sintered light producing method comprising the steps of: preparing a first granulated product by combining a first compounding material containing a first iron ore, a subsidiary material and a fuel; Forming and crushing a second blend material including a second iron ore and a subsidiary material to produce a second blend; And charging the first granulated product and the second granulated product into a sintered bogie.

The method may further include a step of selecting a particle size of the first iron ore and a step of adding iron ore having a particle size of 3 mm or less to the second mixture material in the process of selecting the size of the first iron ore.

And adding a binder in the process of preparing the second blended raw material.

The process for producing the second granulated product may include the steps of: preparing a plate-shaped formed product by compression-molding the second blended raw material; And a step of crushing the plate-shaped formed body to produce a second granulated particle-shaped body.

The size of the second granulated product can be adjusted in the process of crushing the molded product.

The second granulated product may be formed larger than the first granulated product in the process of crushing the formed product.

And mixing the first granule and the second granule.

The step of charging the sintered bogie may include a step of introducing a mixture of the first granulated product and the second granulated product into the sintered bogie.

According to the embodiments of the present invention, it is possible to improve the productivity of a granular material by producing a granulated product by compression-molding a granulated raw material containing fine iron ore and crushing the granulated product, Properties can be secured. In addition, when the sintered ores are manufactured using the granules thus manufactured, the air permeability in the raw material layer can be ensured and the heat quantity can be uniformly adjusted in the height direction of the raw material layer, thereby improving the sintering productivity and quality.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view showing the structure of an apparatus for producing sintered ores according to an embodiment of the present invention; FIG.
BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]
FIG. 3 is a flowchart sequentially illustrating a method for producing sintered ores according to an embodiment of the present invention. FIG.
4 is a conceptual illustration of a method for manufacturing an assembly in an apparatus for manufacturing a product according to an embodiment of the present invention.
5 is a view for explaining the principle of charging a raw material mixture in a method for producing sintered ores according to an embodiment of the present invention.
6 is a view showing a state in which a raw material mixture is charged into a sintering vehicle in the method for producing sintered ores according to an embodiment of the present invention.
Figure 7 is a graph showing the particle size distribution of the first and second assemblies.
8 is a graph showing a comparison of the carbon content according to the height of the raw material layer.
9 is a graph showing a comparison of changes in sintering temperature with the elapse of sintering time.

Hereinafter, embodiments of the present invention will be described in detail. It will be apparent to those skilled in the art that the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, It is provided to let you know.

FIG. 1 is a view schematically showing the construction of an apparatus for producing sintered ores according to an embodiment of the present invention, and FIG. 2 is a schematic view showing a structure of an apparatus for manufacturing granules according to an embodiment of the present invention.

1, an apparatus for producing sintered ores according to an embodiment of the present invention includes a plurality of sintered bogies 200 arranged in one direction to be movable and having a space for heat-treating a blended material therein, A moving path 120 for forming a closed loop such that the carriage 200 rotates in an endless track manner and an ignition path 130 for spraying a flame on the blended raw material charged in the sintered bogie 200. In addition, the sinter ore production facility includes a first pretreatment section 300 for producing a first granulated material using the first granulated material including the first iron ore, and a second pretreatment section 300 for producing the second granulated material containing the second iron ore, A second pretreatment unit 400 for manufacturing the granulated product, and a raw material supply unit 110 for charging the first granulated product and the second granulated product into the sintering bogie 200.

The traveling path 120 forms a closed loop for rotating the sintering bogie 200 in an endless track manner and includes an upper side movement path for charging and sintering the raw material and a sintering bogie 200 for distributing the sintered light, And a lower side movement path for moving the upper side movement path for the sintering process. The upper side movement path may include a raw material supply section, an ignition section, and a sintering section for charging the raw material into the sintering bogie 200. The lower side movement path may include a sagging section for moving the sintering bogie 200 for the next sintering process Lt; / RTI > In this case, the section that is switched from the upper side movement path to the lower side movement path may be the light distribution section 126 where the sintered light is shed. A light shading device 140 for shredding the sintered light to be emitted from the sintering bogie 200 and a cooling device 150 for cooling the shredded sintered light may be provided at one side of the light shading part 126.

The raw material supply part 110 may be provided on one side of the upper side movement path and the ignition furnace 130 may be provided on the front side of the raw material supply part 110 with respect to the moving direction of the sintered bogie 200. In addition, a plurality of wind boxes 121 may be provided at the lower part of the upper side movement path to suck the inside of the sintering bogie from the lower part of the ignition section to the sintering section. The wind box 121 forms a negative pressure and sucks the inside of the sintered bogie 200 to form a flow of air from the upper part to the lower part of the raw material layer inside the sintered bogie 200 to sinter the raw material.

A duct 122 is connected to the end of the wind box 121 and a blower 124 is installed at the end of the duct 122 to generate a negative pressure inside the wind box 121 to thereby suck the inside of the sintered bogie 200 . A dust collector 123 is provided in the duct 122 in front of the blower 124 so that impurities in the exhaust gas sucked through the wind box 121 can be filtered and discharged through the chimney 125. The wind box 121 sucks the outside air to ignite the surface layer of the raw material for sintering and to burn the raw material for sintering so that the sintered ores can be produced.

The first pretreatment unit 300 and the second pretreatment unit 400 may be assembled in a size suitable for producing sintered ores according to the particle size of the iron ores among the raw materials for producing the sintered ores. In this case, the first pretreatment unit 300 may combine the first compounding materials including the first iron ores having a length of 10 cm or less to form a first granule, for example, a pellet, The second blend material containing the second iron ores having a particle size of less than or equal to 탆 can be compression molded and pulverized to produce a second granulated material in the form of particles.

The first pretreatment unit 300 includes a plurality of first hoppers 310 for storing the first iron ore, a sub-raw material and a fuel material, a first mixer 310 for mixing the first iron ore, the sub- (320) and a granulator (330) that combines the first blend material to produce a first blend. The first pretreatment unit 300 may be substantially similar to an apparatus for producing a granulate while mixing and stirring a raw material mixture. That is, the first pretreatment unit 300 uniformly mixes the first iron ores having a particle size of 10 cm or less and the fuel materials such as subsidiary materials such as limestone, coke, and the like in the first mixer 320 to produce a first blend material And a first granulation such as a pellet or the like can be produced by mixing the first iron ore, the sub-raw material, and the fuel material with stirring while adding water to the first mixing raw material in the granulator 330.

The second pretreatment unit 400 includes a plurality of second hoppers 410 for storing the second iron ores, additives and binders, and a second mixture 420 for producing the second mixture materials by mixing the second iron ores and the additives And a granulating device for producing the second granulation product using the granulation material and the second granulation material.

2, the assembling apparatus includes a molding machine 430 for producing a plate-shaped molded body by compression-molding a second blend material, and a plate-shaped molded body manufactured by the molding machine 430, 2 < / RTI > assembly. ≪ RTI ID = 0.0 >

The molding machine 430 may include a twin roll compressor including a pair of first rolls 432. At this time, the pair of first rolls 432 may be spaced apart from each other so as to form a space in which the second blend material is injected therebetween. The molding machine 430 also includes a container 433 in which the second blend material is received and an injector 434 provided inside the container 433 and capable of injecting the second blend material between the first roll 432 . The injector 434 can pressurize the second compounding material between the first rolls 432 so that the molding machine 430 can produce a high-density molded body. For example, the injector 434 may include a screw feeder capable of pressurizing the second blend material between the first rolls 432 at the top of the forming machine 430.

The crusher 440 may include a pair of second rolls 442 spaced apart from each other so as to form a space in which the molded body is inserted.

The crusher 440 may be provided directly under the molding machine 430 so that the molded body manufactured by the molding machine 430 can be crushed in real time. In this case, the second roll 442 of the crusher 440 may be disposed in parallel with the first roll 432 so that a molded body manufactured through the first roll 432 of the molding machine 430 can be inserted. A guide plate 446 may be provided on the second roll 442 to prevent the molded article from being separated. At this time, if the distance D2 between the second rolls 442 is wider than or equal to the distance D1 between the first rolls 432, the formed body can not be broken, so that the interval between the second rolls 442 is The distance between the first rolls 432 is preferably set smaller than the interval between the first rolls 432. The molded body manufactured in the molding machine 430 can be reduced in thickness while being inserted between the second rolls 442 constituting the crusher 440 in an uncured state. The second granulate so produced can have a greater strength than the shaped body because it is pressed twice. A compressor (not shown) may be further provided between the molding machine 430 and the crusher 440 to compress the molded body manufactured by the molding machine 430 using the above-described principle. In this case, the compressor may include a pair of rolls spaced apart from each other like the forming machine 430, wherein the roll-to-roll spacing is smaller than the spacing of the first rolls 432 and larger than the spacing of the second rolls 442 Spacing.

In addition, the second roll 442 may be provided with a projection 444 on its outer circumferential surface so as to easily break the formed body. The protrusions 444 may be provided to have a certain distance D3 on the outer circumferential surface of the second roll 442 at which time the spacing of the protrusions 444 may affect the determination of the size of the second assembly produced by shredding the shaped body I can go crazy. The protrusions 444 can be formed in various shapes and can be formed in a lattice shape, for example, so as to produce a second granulated product in the form of particles having a length, a width, and a thickness by crushing the molded product. The size of the second assembly may be adjusted through the spacing of the second rolls 442 or the size of the protrusions 444 formed on the outer circumferential surface of the second rolls 442.

The apparatus for producing sintered ores according to an embodiment of the present invention may further include a separator 500. The sorter 500 can select iron ores having a particle size of not more than a specific grain size, for example, 1 mm or less or 3 mm or less, from the first iron ores. The iron ore selected in the sorter 500 may be provided to the second pretreatment unit 400 and used to produce the second granule together with the second iron ore.

The raw material supply unit 110 includes a surge hopper 114 for storing the first and second assemblies manufactured by the first pretreatment unit 300 and the second pretreatment unit 400, And a charging device 116 charging the mixing material and the upper light into the upper light hopper 112 and the sintering bogie 200. [ At this time, the first and second assemblies may be mixed in a separate mixer (not shown) and then stored in the surge hopper 114.

Hereinafter, a method for producing sintered ores according to an embodiment of the present invention will be described.

FIG. 3 is a flowchart sequentially illustrating a method for manufacturing sintered ore according to an embodiment of the present invention. FIG. 4 is a conceptual view illustrating a method of manufacturing a granule with the granule manufacturing apparatus according to an embodiment of the present invention, 5 is a view for explaining the principle of charging a blend material in the method of manufacturing an sintered ore according to an embodiment of the present invention, and Fig. 6 is a view showing a state in which blending materials are charged into a sintered bogie in the method of producing sintered ores according to an embodiment of the present invention Fig.

Referring to FIG. 3, the method for producing sintered ores according to an embodiment of the present invention includes a step (S110) of preparing a first iron ore, a step of mixing a first iron ore, (S116), a second iron ore (S120), a second iron ore, an additive and a binder are mixed to form a second blend (S114) A step S124 of producing a plate-shaped molded body by compression-molding the second blended raw material, a step S126 of producing a granular second granulated body by crushing the molded body, (S140) of charging the first granulated product and the second granulated product into the sintering vehicle (S130) and sintering the same. In this case, the first iron ores may have a specific size, for example, a size of 3 mm or less from the first iron ores after the step of preparing the first iron ores. The selected first iron ores having a size of 3 mm or less may be used for producing the second granulated product.

First, the first iron ores may be minute iron ores having a size of 10 cm or less. The first iron ore may be used for producing the first granulated product. If necessary, the second iron ore may be selected from the group consisting of iron ores having a size of 1 mm or less or 3 mm or less from the first iron ores, (Not shown).

When the first iron ore is prepared, the first iron ore is charged into the first mixer 320 together with additives such as limestone and the fuel material, and then mixed uniformly to prepare a first blended raw material. When the first blended raw material is prepared, the first blended raw material is charged into the pelletizer 330 and mixed while adding moisture to combine the first iron ore, the subsidiary raw material, and the fuel material to produce a first pellet such as pellet.

The second iron ores may be fine iron ores having a size of 100 탆 or less. The second iron ores may be used to produce the second granules and may be mixed with second iron ore or second iron ores and iron ores of less than or equal to 1 mm or less than or equal to 3 mm selected from the first iron ores, . When the second iron ores are provided, the second iron ores are charged into the second mixer 420 together with additives such as limestone and binders, and are uniformly mixed to produce a second blended raw material. At this time, the binder may contain at least one of molasses, quicklime (CaO), and water.

Once the second compounding ingredient is prepared, a second granule in the form of an amorphous particle can be produced in the granulation producing device. The second compounding material is press-injected into the molding machine 430 using the injector 434 and the molding machine 430 can press-mold the second material mixture by using the second roll 442 to produce a plate- have. The formed body thus produced may have a thickness of about the interval of the second rolls 442. Since the action of a force opposite to the rotation direction of the forming roll is not required during the production of the briquettes by the above-described method, it is possible to manufacture a plate-shaped molded body having a relatively high production speed and uniform strength as compared with the case of producing briquettes have.

The formed body is fed to a crusher 440 under the crusher 440. The crushed body is passed through the crusher 444 of the crusher 440 and the crusher 440 formed on the outer circumferential surface of the second roll 442 To form a second granulation in particle form. At this time, since the compact is crushed while being pressed again by the second roll 442, the second granulate can have a higher compressive strength than the compact. When the second granulated product is produced by crushing the molded product, the second granulated product may be formed to have a size larger than the particle size or the particle volume of the first granulated product. The size of the second assembly can be controlled by adjusting the distance between the second rolls 442.

The reason why the size of the second granulated product is larger than the size of the first granulated product is to uniformly control the sintering heat amount in the height direction of the raw material layer in the sintered bogie 200 during the sintering process. In other words, since the second granulated product does not contain the first granulated product and the fuel material, the amount of heat required for sintering can not be generated when it is charged into the upper layer of the raw material layer formed on the sintered bogie 200. Therefore, there is a problem that a fuel gas such as LNG, an oxygen-containing gas or the like must be additionally supplied to the upper portion of the raw material layer in order to supplement the heat quantity required for sintering. Accordingly, the second granules not containing the fuel material can be formed to have a size larger than that of the first granules so as to be charged into the lower layer portion of the raw material layer where excessive heat is generated during sintering.

After the second granulation product is manufactured, it may be mixed with the first granule manufactured in the first pretreatment part 300 and then stored in the surge hopper 114 of the raw material supply part 110.

Thereafter, a mixture of the upper light, the first granulated product and the second granulated product, that is, the blended raw material is charged into the sintered bogie 200 moving along the movement path 120 by using the charging device 116 to form a raw material layer do.

The loading of the compounding material can be carried out such that the particles are segregated in the height direction of the sintering bogie 200 based on the principle of powder segregation. Referring to FIG. 5, as a graph for explaining the principle of powder segregation, particles of raw material discharged from the charging device 116 are separated from the inclined surface of the charging device 116 at a speed of V and have a? . According to the well-known trajectory effect of William, as shown in the following equation (1), the horizontal falling distance L of the powder is determined by the horizontal leaving velocity V _h of the particle, the density (rho) (d).

(Where, in the equation (1), is the air viscosity)

That is, the larger the density and the diameter of the particles, the larger the horizontal departure velocity V _h , the greater the drop distance, and the larger the horizontal departure velocity V _{h of} particles having the same density p and diameter d, Layer. The higher the degree of segregation, the more space is secured between the particles, thereby improving the breathability. That is, when particles having different densities and diameters are mixed and laminated, for example, particles having a small diameter are mixed between particles having a large diameter, resulting in loss of space between particles, resulting in low air permeability.

Here, in order to increase the horizontal release speed V _h of the particles, it is inevitable to change the structure of the charging device 116. However, in this case, since the size of the facility must be increased, it is not feasible in terms of production, control, and economy. Therefore, it is preferable to control the size of the blended raw material in order to effectively load the blended raw material into the segregation.

Therefore, in the present invention, the size of the second granulated product is made larger than that of the first granulated product, and the second granulated product is loaded into the lower layer portion of the raw material layer to improve the air permeability of the raw material layer. Can be controlled.

That is, since the second granules containing no fuel material are charged into the lower layer portion of the raw material layer to suppress or prevent the accumulation of heat in the lower layer portion during the sintering process, when the sintering / By increasing the velocity to the maximum, the effect of segregation loading into the sintered bogie is increased, thereby improving the air permeability of the raw material layer in the sintered bogie, thereby improving the quality and productivity of the sintered ores.

6 shows a state in which a mixture of the first granulated product and the second granulated product, that is, the blended raw material, is charged into the sintering bogie 200. In FIG. Referring to FIG. 6, the blended raw material is charged into the sintering bogie 200 by the charging device 116. At this time, the second granulated material having a relatively large particle size is charged to the lower side of the sintered bogie 200, . The first granulated material having a relatively small particle size is loaded on the upper side of the sintering bogie 200 to form the upper layer of the raw material layer. Here, it is described that the first granule forms the upper layer portion of the raw material layer and the second granule forms the lower layer portion of the raw material layer. However, according to the particle size of the first granule and the second granule, . That is, since the second granules are produced by crushing the formed bodies, they do not all have the same size, and may have the same size as the first granules, or may have a smaller size than the first granules.

When the blended raw material in which the first granulated product and the second granulated product are mixed is vertically seamed into the sintered bogie 200 in this way, the sintered bogie 200 moves along the moving path 120, And the sintering of the raw material layer can proceed.

In order to confirm the possibility of improving the process efficiency and the productivity in the case of producing the sintered ores by the above-described method, the following tests were performed, and the results of the tests are shown in FIGS. 7 to 9.

FIG. 7 is a graph showing the particle size distribution of the first granulated product and the second granulated product, FIG. 8 is a graph showing a comparison of carbon contents according to the height of the raw material layer, FIG. 9 is a graph showing changes in sintering temperature FIG.

[Iron ore preparation]

Iron ore to be used as a raw material of the sintered ores was prepared for the test. The chemical composition and particle size of the iron ore used in the test are shown in Table 1 below.

ironstone
Chemical composition (wt%) Granularity T.Fe FeO SiO ₂ Al ₂ O ₃ CaO MgO Average particle diameter
(Mm) 0.15 mm or less
(wt%) A 58.70 0.22 4.49 1.51 0.05 0.05 2.68 5.3 B 65.55 0.24 1.62 1.57 1.72 0.17 1.55 20.7 C 66.74 0.47 2.41 0.40 0.02 0.03 0.09 92.0

Iron ore A and iron ore B are representative sintered iron ores, and can correspond to the first iron ore described above. At this time, iron ore B has a higher differential ratio than iron ore A. Iron ore C is a hematite fine powder ore (or pellet feed) and has a very high specific gravity (particle size of 0.15 mm or less) of about 90% by weight. Iron ore C may correspond to the above-mentioned second iron ore.

[Manufacture of granules]

Iron ore A and iron ore B were manufactured as a first granulation product through a first pretreatment part 300 and iron ore C was manufactured as a second granulation product through a second pretreatment part 400. At this time, the first assemblies manufactured through the first preprocessing unit 300 are referred to as STD1 and STD2. And the second assemblies manufactured through the second preprocessing section 400 are referred to as PA1, PA2, and PA3. The first granulate was prepared to contain the sub-raw material and the fuel material together with the iron ore A, and the second granulate was made to include the sub-raw material and the binder.

The second granulation product was manufactured using the second pretreatment part 400 according to the embodiment of the present invention. At this time, the interval between the first rolls 432 of the molding machine 430 was adjusted to 1 cm to manufacture a plate- The second granules were produced by progressively increasing the interval between the second rolls 442 of the post-crusher 440 in the range of 1 to 2 cm to crush the formed body. At this time, the second granulation manufactured by adjusting the interval of the second rolls 442 to 12 mm is called PA1, and the second granulation manufactured by adjusting the interval of the second rolls 442 to 16 mm is PA2 And the second granulation produced by adjusting the interval of the second rolls 442 to 20 mm is referred to as PA3.

[Manufacture of sintered ores]

Samples were prepared using the first and second assemblies, and sintered ores were prepared using the samples.

Sample 1 was prepared from 30 kg of the first granulation product. The first sample was charged into a sintering port having a diameter of 150 mm to form a raw material layer. The surface layer of the raw material layer was ignited. The sintering was carried out while sucking under pressure. At this time, the first granulated product is made to contain iron ore A.

In Sample 2, 30 kg of the mixture of the first granulated product and the second granulated product PA2 was charged into a sintering port having a diameter of 150 mm to form a raw material layer. After the surface layer of the raw material layer was ignited, 1,500 mmAq Lt; / RTI > under pressure. At this time, the first granule and the second granule PA2 were mixed so as to have a weight ratio of 80:20 with respect to the total weight of the sample 2.

In Sample 3, 30 kg of a mixture of the first granulated product and the second granulated product PA3 was charged into a sintering port having a diameter of 150 mm to form a raw material layer. After the surface layer portion of the raw material layer was ignited, 1,500 mmAq Lt; / RTI > under pressure. At this time, the first granulation product and the second granulation product PA3 were mixed so as to have a weight ratio of 80:20 with respect to the total weight of the sample 3.

In Sample 4, 30 kg of a mixture of the first granulated product and the second granulated product PA2 was charged into a sintering port having a diameter of 150 mm to form a raw material layer. After the surface layer portion of the raw material layer was ignited, 1,500 mmAq Lt; / RTI > under pressure. At this time, the first granule and the second granule PA2 were mixed so as to have a weight ratio of 80:10 with respect to the total weight of the sample 4.

In Sample 5, 30 kg of a mixture of the first granulated product and the second granulated product PA2 was charged into a sintering port having a diameter of 150 mm to form a raw material layer. After the surface layer of the raw material layer was ignited, 1,500 mmAq Lt; / RTI > under pressure. At this time, the first granule and the second granule PA2 were mixed so as to have a weight ratio of 80:20 with respect to the total weight of the sample 5.

Samples 1 to 5 contain the same amount of fuel material and contain 3 wt% of fuel material with respect to 100 wt% of each sample.

[Test result]

Firstly, the weight ratio of the second granule according to the particle size was examined when the interval between the second rolls 442 of the crusher 440 was adjusted when the second granule was manufactured using iron ore B. FIG. 9 shows the accumulation amount of the first granulated product produced using iron ore A according to the weight ratio particle size change according to the particle size. The second granules were crushed while changing the distance between the second rolls 442 in the range of 1 to 2 cm so that the average particle size and distribution of the second granules were adjusted according to the distance between the second rolls 442 . Referring to FIG. 9, as the distance between the second rolls 442 increases, the size of the second granular material increases substantially.

And the particle size distribution of the first granule and the second granule at a cumulative amount of 50%, the first granule has a size of about 2.5 mm or less and the second granule has about 4.5 to 10.5 mm or less. This indicates that the particle size of the second granulate is relatively large compared to that of the first granule.

Further, as the distance between the second rolls 442 increases, the fraction of the second granules decreases. In the case of the second granulated product PA1 and the second granulated product PA2, the accumulation amount of the second granulated product PA1 is about 40% and the accumulation amount of the second granulated product PA2 is about 12% to be. This means that as the distance between the second rolls 442 decreases, the fraction of the second granules produced by crushing the formed body increases.

As a result, it can be seen that the particle size distribution of the second granule can be appropriately adjusted by adjusting the distance between the second rolls 442 when the compact is crushed.

Next, the distribution of carbon content in the raw material layer charged into the sintering port was examined.

In the test for producing sintered ores using samples 1 to 5, the carbon content according to the height of the sintered pot was measured and shown in FIG.

8 (a), in the case of the sample 1 made only of the first granule, although the carbon content is somewhat higher in the upper portion of the sintering port, it is about 1% by weight The range of variation is shown.

8 (b) shows the result of measuring the carbon content along the height direction of the sintering port by charging the sintering port with the sample 1 and the sample 2 made of the first granule and the second granule, respectively. Referring to FIG. 8 (b), the carbon content difference between the lower layer and the upper layer of the raw material layer is larger than that in the case where only the sample 1 is charged into the sintering port. It can also be seen that when the sample 3 containing a large amount of the second granulated material having a larger particle size than that of the first granulated material is charged into the sintering port, the carbon content is higher in the upper layer than when the sample 2 is charged into the sintering port . This may mean that the secondary granules, which do not contain the carbonaceous material, are charged into the lower portion of the sintering port by a large amount of the fuel material, that is, the carbon component.

8 (c) shows the carbon content distribution according to the content of the second granulate in the blend stock when the second blend is manufactured using the same distance between the second rolls 442. Fig. Referring to FIG. 8 (c), it can be seen that the carbon content is higher in the upper portion of the sintered pot when the sample 5 having a larger amount of the second granulate is charged into the sintering port under the same condition of the second granulated product .

According to the test results, when the first granulated material is mixed with a second granulated material having a larger particle size and no fuel material than the first granulated material, the carbon content in the height direction of the raw material layer Can be adjusted. Further, the carbon content in the height direction of the raw material layer can be finely adjusted according to the size of the second granulated product.

In the following, we examined the temperature changes according to the height of the raw material layer while carrying out the sintering test by charging Sample 1 and Sample 4 into the sintering port, respectively.

Fig. 9 shows the comparison of the temperature distribution at three locations in the height direction of the sintering port with the elapse of the sintering time.

Referring to FIG. 9, in the sintering test using the sample 1 including only the first assembly, a temperature difference of about 300 ° C. is shown between the upper and lower layers as the sintering time elapses. At this time, the temperature indicated in each region of the sintering port is the highest temperature in each region. On the other hand, in the sintering test using the sample 4 in which the first granulated product and the second granulated product are mixed, it can be seen that the temperature difference between the upper and lower layers hardly appears as the sintering time passes. When the sample 4 was used, the temperature of the upper layer was increased by about 150 ° C. (t 1), and the temperature of the lower layer was lowered by about 100 ° C. (t 2).

In addition, it can be seen that the time to reach the maximum temperature in each region when the sintering is proceeded using the sample 4 is shorter than that when the sample 1 is used.

This is because most of the second granules not containing the fuel material are charged into the lower portion of the sintering port by the segregation inlet and most of the first granules containing the fuel material are charged into the upper portion of the sintering port, This is because the phenomenon of accumulation of heat in the lower layer is suppressed and the amount of heat that is supplied to the upper layer is supplied by the fuel material which is charged intensively in the upper layer.

Further, it can be seen that airtightness in the raw material layer is ensured by segregation charging, and the sintering time can be shortened.

As a result, the sintering temperature can be uniformly controlled in the height direction of the raw material layer because the distribution of the fuel material in the raw material layer can be controlled in the case of producing the sintered ores by the method of producing the sintered ores according to the embodiment of the present invention, And the sintering light quality can be improved.

Although the present invention has been described in detail with reference to the specific embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited by the described embodiments, but should be defined by the appended claims, as well as the appended claims.

200: sintering ladle 300: first pretreatment part
400: second pre-processor 430: molding machine
440: Crusher

Claims (8)

A method for producing sintered ores,
Combining a first compounding raw material including a first iron ore, a subsidiary raw material and a fuel to produce a first granulated product;
Forming and crushing a second blend material comprising a second iron ore having a particle size smaller than that of the first iron ore and an additive, thereby producing a second blend; And
And charging the first granulated product and the second granulated product into a sintered bogie,
The process of producing the first granule may include:
Adding water to the first compounding raw material while stirring to form a first granular product in the form of pellets by bonding the first iron ore,
The process of producing the second granule may include:
A step of injecting the second compounding material between a pair of first rolls and compression molding the mixture to produce a plate-like shaped body;
Compressing the plate-like formed body;
A step of preparing a granular second granule by inserting and compacting a compressed plate-like formed body between a pair of second rolls having protrusions formed on the outer circumferential surface thereof;
/ RTI >
Wherein the second granulated product is produced by crushing a plate-shaped formed product produced in a molding machine in real time to form a second granulated product. The method according to claim 1,
And a step of selecting a particle size of the first iron ore,
And adding iron ores having a particle size of 3 mm or less to the second blending raw material in the course of selecting the first iron ores. The method of claim 2,
And adding a binder in the process of preparing the second compounding raw material. delete The method of claim 3,
The step of crushing the molded body comprises:
And adjusting the size of the second granules by adjusting the size of the projections. The method of claim 5,
Wherein the second granules are formed larger than the first granules in the process of crushing the granules. The method of claim 6,
And mixing the first granulated product with the second granulated product. The method of claim 7,
And charging the sintered bogie with a mixture of the first granulated product and the second granulated product into the sintered bogie.

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