KR20110042361A - Sintered ore manufacturing method - Google Patents

Abstract

It is a manufacturing method of a sintered ore which mixes iron-containing raw material containing a plurality of items of iron ore, a subsidiary material, a solid fuel, and a semi-ore, and makes it a sintering raw material, mixes and granulates these sintering raw materials, loads it on a sintering pallet, and bakes, Based on the melt penetration distance measured for each item of the iron ore, from the iron ore of the plurality of items, a high melt permeable iron ore selected or blended such that the weighted average value of the melt penetration distance is 4.0 mm or more is formed on the sintered pallet. Charged in the upper layer in the range of 5 to 12% in the layer thickness ratio with respect to the total layer thickness from the upper surface of the raw material filling layer formed in the above, and charging other iron ore into the lower layer of the raw material filling layer, and further A solid fuel and the semi-glossy are charged into the upper layer and the lower layer of the raw material filling layer.

Description

Manufacturing method of sintered ore {SINTERED ORE MANUFACTURING METHOD}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing sintered ore used as a steelmaking raw material, and more particularly to a method for producing sintered ore for improving the product yield and strength of the upper part of the raw material filling layer formed in the sintered pallet.

This application claims priority based on Japanese Patent Application No. 2008-238448 for which it applied to Japan on September 17, 2008, and uses the content here.

In recent years, Australia's iron ore, which is a major iron ore used in Japan, has been depleted of high-quality hematite ore, and in the present state, the pisolite deposit, the maramamba deposit and the deceased brock are present. Development of bare deposits is in progress.

Iron ores calculated from the maramamba deposit or the decayed Brockman deposit have a smaller particle size and higher content of crystal water than high-quality hematite ores. Therefore, at the time of sintering, these iron ores cause a decrease in air permeability and deterioration of sintering reactivity.

The existing pisolite ore calculated from the pisolite deposit is a high crystal water ore. In the iron ore calculated from this pisolite ore, maramamba or decayed Brockman deposits, 90% is iron ore whose crystal water content is 4% by mass or more.

The influence on the sintering operation when a large amount of high crystallized water ore is blended as the sintering raw material will be described below.

Generally, manufacture of the sintered ore using the lower suction type sintering machine is performed as follows.

The sintered raw material includes iron-containing raw materials such as iron ore, which is the main raw material, and iron dust generated in the iron making process, secondary raw materials such as limestone and serpentine required for the sintering reaction, and solid fuel such as coke powder as a heat source, use.

Before the sintered raw material is charged into the downward suction type sintering machine, it is mixed and granulated while adding water using a mixing / assembling machine such as a drum mixer, and processed into pseudo particles. This pseudo particle mainly consists of a nuclear particle of 1 mm or more of particle diameter, and the adhesion powder of 0.5 mm or less of particle diameter adhering around it.

By charging the sintering raw material processed with this pseudo particle in a sintering machine, the air permeability in the sintering filling layer formed in the sintering pallet is maintained, the sintering reaction of the sintering raw material is promoted, and high productivity can be ensured.

The sintered raw material processed into the pseudo particle is charged into the sintered pallet from the light feeding part of a sintering machine, and forms a raw material filling layer. Thereafter, in the ignition furnace, the coke powder on the surface of the raw material filled layer is ignited and air is sucked from the lower part of the sintering machine to move the combustion point of the coke powder below the raw material packed layer.

The sintering reaction progresses sequentially from the upper layer of the raw material filling layer to the lower layer by the combustion heat of the coke powder, and the sintering is completed until the sintered pallet moves to reach the light distribution part. After the sintered cake (lump) in the sintered pallet is discharged from the light distribution part, it is crushed to produce a sintered ore for blast furnace having a predetermined particle size.

Since the sintered ore powder smaller than the predetermined particle size generated in the production of the sintered ore cannot be used as the sintered ore for blast furnace, it is blended in the sintered raw material as semi-glossy and sintered again.

Sintering reaction of a sintering raw material advances mainly by generation | occurrence | production of the following initial melt and subsequent assimilation reaction in 1200 degreeC vicinity. That is, the initial melt of calcium ferrite (CaO-Fe ₂ O ₃ ) is produced by the reaction of Fe ₂ O ₃ in the iron-containing raw material and CaO in the limestone. Thereafter, an assimilation reaction is carried out in which the components in the iron ore and the components in the sub-material are dissolved in the initial melt.

This sintering reaction is a very fast reaction completed in about several minutes from the production | generation of initial stage melt. By this reaction, the quality, such as the product yield and productivity of a sintered ore, the intensity | strength of a sintered ore, etc. are greatly influenced.

For example, when the sintering reaction proceeds excessively and the amount of melt formed is extremely increased, the air permeability in the sintered layer deteriorates in the sintering operation. Since combustion nonuniformity arises by this air permeability deterioration, product yield and productivity fall, and the quality of sintered ores, such as intensity | strength, also worsens.

On the other hand, when the sintering reaction does not proceed sufficiently, the melt for bonding the unmelted parts such as residual iron ore (remaining ore) decreases, so that the yield of the product is lowered and the quality of the sintered ore such as strength or reduction differentiation (RDI) is reduced. This gets worse.

This sintering reaction is a main raw material in a blended raw material, and is largely influenced by the sinterability (activation property) resulting from the mineral composition or property of iron ore which occupies 60% or more of the whole, and the granulation property which determines the air permeability of the sintering raw material filling layer.

In the case of blending high-crystallized iron ore such as pisolite ore as iron ore, crystal water derived from goethite structure in iron ore starts pyrolysis and dehydration from around 300 ° C, whereby cracks occur in the goethite tissue. .

As a result, pores are formed in the initial melt, a solidified binding phase is generated while the generated pores remain, or unmelted ore including cracks remains. As a result, the sintered ore is weak and becomes a porous structure, and the yield of the sintered ore is degraded, and the quality of the sintered ore, such as strength, is deteriorated.

In addition, when sintering raw materials contain high content of crystal water such as maramamba ore or staple ore and have a fine grain size of iron ore, in addition to the problems caused by the above-mentioned crystal water, granulation performance deteriorates. Therefore, pseudo particle | grains are hard to produce | generate, and pseudo particle | grains become easy to collapse at the time of conveyance or raw material loading.

For this reason, when charging a raw material into a pallet, the fine granulated iron ore which is not granulated, or the fine powder of the iron ore which collapsed and produced is segregated and distributed in the upper layer side of a raw material filling layer, and the air permeability of an upper layer falls. In addition, the goethite structure containing the crystal water is fragile, and therefore exists in many iron ore particles having a fine particle size.

For this reason, the fine particle of iron ore which segregates and distributes on the upper layer side of a raw material filling layer may be a cause which causes the problem caused by said crystal water.

Generally, in manufacture of the sintered ore using a downward suction type sintering machine, the temperature of the surface layer part of the raw material filling layer after complexing falls by suction of air near room temperature. Therefore, quality deterioration, such as the fall of the product yield of sintered ore in an upper layer part, and intensity | strength, has conventionally become a problem.

Problems of quality, such as the product yield and strength of the sintered ore in this upper layer part, are remarkable in the recent sintering operation which mixes high crystalline water iron ore and fine iron ore as sintering raw materials.

In the manufacture of the sintered ore using the said downward suction type | mold sintering machine, the method for improving the quality, such as the product yield and intensity | strength of the upper layer part of a sintering raw material filling layer, has been proposed a lot.

For example, the method (for example, refer patent document 1) of increasing the solid fuel of the upper layer part of a raw material filling layer is proposed.

In addition, a method of charging a granulated material of high FeO ferromagnetic raw materials such as semi-gloss, mill scale, magnetite, and ferromagnetic raw materials and carbonaceous materials to the surface layer portion of the raw material filling layer by a charging device using magnetic materials (for example, Patent Documents 2 to 2) 6).

Furthermore, in consideration of the assimilability of the iron ore blended into the sintered raw material, a method of charging a molten iron ore into the upper layer of the raw material filling layer and inserting a hard molten iron ore into the lower layer thereof (Example For example, Patent Document 7) is also proposed.

In other words, to raise the temperature of the surface layer of the raw material charge layer after ignition, to increase the solid fuel in the surface layer of the raw material charge layer, or, CaO in the additives in the surface layer of the raw material charge layer or SiO ₂ and the melt (CaO-SiO ₂ -FeO Ferromagnetic raw materials, molten iron ores, etc. containing a large amount of FeO, which are easy to form), are charged. These methods aim at improving the quality of the sintered ore in the upper part of the raw material filling layer and the quality such as strength.

However, according to these methods, since it is difficult to appropriately control the amount of heat and the amount of melt generated in the upper layer of the raw material filling layer, the amount of heat is excessively high or the melt is excessively increased. Therefore, the air permeability of the whole raw material filling layer deteriorates, productivity falls, and there existed a problem that the quality of sintered ores, such as a reducing property, fell.

Japanese Patent Application Laid-Open No. 2000-144266 Japanese Patent Application Laid-Open No. 2000-328148 Japanese Patent Application Laid-Open No. 2001-234257 Japanese Patent Application Laid-Open No. 2001-271122 Japanese Patent Application Laid-Open No. 2001-335849 Japanese Laid-Open Patent Publication No. 2002-130957 Japanese Patent Publication No. 60-47887

In view of the above problems of the prior art, the present invention provides a raw material filled layer by selectively charging iron ore of an item having excellent melt permeability into the powdered portion in the upper layer of the raw material filled layer in the method for producing a sintered ore using a downward suction type sintering machine. To prevent excessive increase in the melt of the upper layer, and to improve the product yield and strength of the upper layer of the raw material filling layer without deteriorating the air permeability of the entire raw material filling layer, and degrading the quality of the sintered ore, such as the reducing property, An object of the present invention is to provide a method for producing a sintered ore that can improve the productivity of the sintered ore.

MEANS TO SOLVE THE PROBLEM The present inventors earnestly examined the method for improving the product yield and intensity | strength of the upper layer of the raw material filling layer formed in a sintered pallet in manufacture of a sintered ore.

As a result, the upper layer of the predetermined | prescribed range of the raw material filled layer in which iron ore whose melt penetration distance measured by the melt permeability evaluation test in iron ore powder is 4.0 mm or more is formed on the sintered pallet among the iron ore of the several items which comprise a sintering raw material. By selectively charging in, it was confirmed that the product yield and strength of the sintered ore in the upper layer of the raw material filling layer can be improved.

Moreover, according to this method, compared with the method of increasing the solid fuel and FeO source of the upper layer of the raw material filling layer conventionally proposed, or charging molten iron ore into the upper layer of the raw material filling layer, It was found that the yield and strength of the sintered ore in the upper layer of the raw material filling layer can be improved without excessive melt being generated and lowering the air permeability of the entire raw material filling layer.

This invention is made | formed based on the said knowledge, The summary of this invention is as follows.

(1) Preparation of a sintered ore which contains a plurality of iron-containing raw materials, secondary raw materials, solid fuels, and semi-ores containing iron ore as a sintering raw material, these sintering raw materials are mixed and granulated, and then charged onto a sintered pallet and fired. And a high melt permeable iron ore selected or blended from the iron ores of the plurality of items based on the melt permeation distance measured for each item of the iron ore such that a weighted average value of the melt permeation distance is 4.0 mm or more. Charged from the upper surface of the raw material filling layer formed on the sintered pallet to the upper layer in the range of 5 to 12% in the layer thickness ratio with respect to the total layer thickness, and other iron ores into the lower layer of the raw material filling layer, Subsidiary materials, the solid fuel, and the semi-reflective charge are charged into the upper layer and the lower layer of the raw material filling layer.

(2) In the production process of sintered ore according to the item (1), in which the two may be an Al ₂ O ₃ content of the iron melt permeability than 0.6% by mass.

(3) In the method for producing a sintered ore according to the above (1), in addition to the high melt permeable iron ore, as the iron-containing raw material, the scale generated in the steelmaking process is applied to the total layer thickness from the upper surface of the raw material filling layer. You may charge in the upper layer of 5 to 12% of range in layer thickness ratio.

(4) In the manufacturing method of the sintered ore of the said (1), the said solid fuel and the said semiglow may be charged in the same compounding ratio in the said upper layer and the said lower layer of the said raw material filling layer.

(5) In the manufacturing method of the sintered ore of the said (1), the mixing ratio of the said upper layer may be below the compounding ratio of the said lower layer with respect to the said sub raw material charged to the said raw material filling layer.

(6) In the method for producing a sintered ore according to the above (1), the high melt permeable iron ore and the other iron ore mix the secondary raw material, the solid fuel and the semi-ore, mix and assemble, and then the raw material filling layer. You may charge in the said upper layer and the said lower layer, respectively.

(7) In the method for producing a sintered ore according to (6), the high melt permeable iron ore mixes the scale generated in the iron making process as the iron-containing raw material, and blends the sub-raw material, the solid fuel, and the semi-glossy. After mixing and assembling, the mixture may be charged into the upper layer of the raw material filling layer.

According to this invention, in the manufacturing method of the sintered ore using a downward suction type | mold sintering machine, melt permeability to the fine part of each item iron ore mix | blended with a sintering raw material is evaluated, and based on this evaluation result, in each iron ore of each item, By selecting iron ore of an item having excellent melt permeability into the finely divided portion and selectively charging it in the upper layer of the raw material filling layer, it is possible to improve the product yield and strength of the upper layer of the raw material filling layer and improve the productivity of the sintered ore.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the microscopic structure of the pseudo particle cross section of the sintering raw material taken from the raw material filling layer of a sintering machine.
It is a figure which shows the relationship between the melt penetration distance of iron ore and intensity | strength SI of sintered ore in actual sintering operation.
FIG. 3 is a graph showing the relationship between the melt penetration distance of iron ore and the yield of sintered ore in actual sintering operation.
It is a figure which shows the measurement position of melt penetration distance in the tablet after baking.
It is a figure which shows the comparison of the melt penetration distance of iron ore of a main item.
It is a figure which shows the relationship between the melt penetration distance of iron ore and the intensity | strength index (+0.5 mm% value) by the drop test in tablet baking test.
It is a figure which shows the relationship between the upper loading layer thickness ratio, and intensity | strength SI of sintered ore in a sintering ladle test.
FIG. 8 is a diagram showing the relationship between the upper charge layer thickness ratio and the product yield of sintered ore in the sintering ladle test. FIG.
9 is a graph showing the relationship between the melt penetration distance of iron ore and the Al ₂ O ₃ content.
It is a figure which shows the relationship between the limestone ratio in an upper layer, and the yield of the sintered ore in the sintering ladle test.
It is a figure which shows the relationship between the limestone ratio in an upper layer, and the intensity SI of sintered ore in a sintering ladle test.
It is a figure which shows the charging condition of the sintering raw material of the sintering ladle test of an Example.
It is a figure which shows an example of the method of charging high melt permeability iron ore and other iron ores into the upper layer and lower layer of a raw material filling layer, respectively.

First, the technical idea of this invention is demonstrated.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the optical microscope structure of the pseudo particle cross section of the sinter raw material taken from the raw material filling layer of a sintering machine.

It is thought that the initial melt in the sintering process is generated at the contact portion of iron ore (Fe ₂ O ₃ ) and limestone (CaO). However, as shown in FIG. 1, according to the micro observation of the adhesion powder part (differential part) of the pseudo particle | grains (consisting of the nuclear particle of 1 mm or more of particle diameters, and the adhesion powder part of 0.5 mm or less of its surroundings) of a sintering raw material, iron ore Since (Fe ₂ O ₃ ) and limestone (CaO) are irregularly distributed, there are few parts in contact with them.

From this, in an actual sintering process, it is thought that a sintering reaction advances as follows. That is, the initial melt of calcium ferrite (CaO-Fe ₂ O ₃ ) is produced in the portion where iron ore (Fe ₂ O ₃ ) and limestone (CaO) are in contact with the powder portion of the pseudo particle of the sintered raw material. Thereafter, the initial melt penetrates into the adhered powder portion, contacts with the surrounding iron ore and the subsidiary materials, and repeats assimilation and coalescence. In this way, the amount of melt increases and a bonding phase of sintered ore is formed.

In addition, the present inventors clearly clarify that the initial melt generated during the sintering process penetrates into the iron ore packed layer, i.e., the melt permeability greatly affects the formation of the bonded phase of the sintered ore, depending on the mineral properties of the iron ore. [ISIJ-Int. 43 (2003), p. 1384, see.

The temperature of the upper layer of the sinter raw material filling layer during the sintering operation tends to be lowered, and the time from the initial melt formation of iron ore (Fe ₂ O ₃ ) and limestone (CaO) to the completion of the sintering reaction (assimilation reaction) is short. From this, the present inventors selectively charge iron ore having high melt permeability into the upper layer of the raw material filling layer and improve the yield of the initial melt rapidly in order to improve the product yield of the sintered ore in the upper layer of the raw material filling layer. It was thought that it was effective to infiltrate in the middle and to accelerate an assimilation reaction.

The present invention is made on the basis of this technical idea, and is a sintered raw material containing iron-containing raw materials including a plurality of items (iron ore items), secondary raw materials (limestones, etc.), solid fuels (coke, etc.) and semi-ores. In the manufacturing method of the sintered ore which mixes and granulates a sintering raw material, loads on a sintering pallet, and bakes, it has the following characteristics. That is, an evaluation test of melt permeability for each item of the iron ore is performed, and based on the measured value of the melt permeation distance of each item, the iron ore composed of one or more kinds such that the melt penetration distance is 4.0 mm or more from the iron ore of the plurality of items. Is selected or blended and charged in the upper layer so that the layer thickness ratio (upper charge layer thickness ratio) with respect to the total layer thickness is in the range of 5 to 12% from the upper surface of the raw material filling layer formed on the sintered pallet. It is done.

In the present invention, the melt permeability of iron ore (easiness of diffusion when the initial melt penetrates into the iron ore powder having a particle diameter of 0.5 mm or less) and the melt permeation distance (the penetration distance of the melt in the iron ore powder) are determined by the present inventors. It can evaluate and measure by the evaluation test (henceforth "melt permeability evaluation test of iron ore") proposed by 2002-62290.

This melt penetration distance used the weighted average value of the melt penetration distance of the iron ore of each item measured for the sake of simplicity when mix | blending the iron ore of 2 or more types of items as iron ore of a sintering raw material. Hereinafter, when using the iron ore which mix | blended the iron ore of 2 or more types of items, the weighted average value is also expressed as melt penetration distance. Moreover, you may mix | blend iron ore of several items, and may measure melt penetration distance as iron ore of 1 type of items.

In addition, although melt penetration distance in this invention evaluated by the said melt permeability evaluation test of this invention, you may evaluate melt permeability by another evaluation test and may convert it into the melt penetration distance in this invention. For example, it may change into the melt penetration distance in this invention, changing evaluation of the shaping | molding pressure of the said iron ore melt penetration test, the size and shape of an iron ore tablet, and an initial melt material tablet, a test procedure, etc. For example, the melt penetration time in the present invention may be measured by measuring the time at which the melt has penetrated the predetermined distance, and converting it into the melt penetration distance in the present invention. What is necessary is just the physical quantity convertible into.

The melt permeability evaluation test of iron ore in this invention is performed with the following methods, and measures melt penetration distance.

The iron ore sample is adjusted by mixing the particle size so that the proportion of the particle size: 0.25 to 0.5 mm is 50 mass%, and the proportion of the particle size: 0.25 mm or less is 50 mass%. Thereafter, an iron ore sample was molded at a molding pressure of 4 MPa using a mold forming die, and an iron ore tablet having a diameter of 15 mm and a height of 5 mm (porosity (open porosity) by a mercury porosimetry): about 30%). To produce.

On the other hand, the initial melt material is a Fe ₂ O ₃ reagent and so as to have a composition of CaO: 26 mass%, Fe ₂ O ₃ : 74 mass% close to the eutectic composition of the binary system diagram of CaO-Fe ₂ O ₃ CaO reagents are combined and mixed for 20 minutes by automatic induction. Thereafter, similarly to the iron ore tablet, the initial melt material is molded at a molding pressure of 4 MPa using a mold forming die to produce an initial melt material tablet having a diameter of 5 mm and a height of 5 mm.

Further, the initial melt material tablet is placed in the center of the upper surface of the iron ore tablet, charged into a cylindrical cylindrical ladle made of Ni (inner diameter of 20 mm, height of 15 mm), heated in an air flow in an electric furnace, and fired. Then, melt penetration distance is measured by cross-sectional observation of the tablet after baking.

In addition, in the measurement of the melt penetration distance in the tablet after baking, it cuts perpendicularly in the tablet radial direction center part, grinds a cut surface, and observes the mineral structure of the cut surface shown in FIG. 4 with an optical microscope. In the photographed cross-sectional structure, the width direction (tablet radial direction) center part 3 of the part which melt | dissolution melted shown in FIG. 4, and this intermediate point of this center part 3 and the outer edge parts 1 and 5 are It is preferable to measure a penetration distance at three places of (2) and (4), and to calculate melt penetration distance from those average values.

In the said evaluation test, the baking conditions of a tablet use the sintering heat pattern similar to a real machine. In other words, the tablet is heated from 1100 ° C to 1290 ° C (maximum temperature) in 1 minute, and then cooled from 1290 ° C to 1100 ° C in 3 minutes, and the tablet is immediately taken out of the furnace and air cooled.

In the practical sintering operation using iron-containing raw materials containing a plurality of iron ores, FIG. 2 shows the relationship between the melt penetration distance of iron ore and the strength SI of the sintered ore, and FIG. Represents a relationship.

SI, which is an index indicating the strength of the sintered ore, is measured by collecting 10 kg of sintered ore having a particle diameter of 10 to 25 mm from the sintered ore after measuring the following property yield and dropping it four times from a height of 2 m. This SI shows the ratio (mass%) of the mass (kg) of the sintered ore: 5 mm or more of particle diameter after a fall with respect to the mass (kg) of the sintered ore before falling.

The product yield of the sintered ore is measured by dropping the sintered cake (lump) five times from a height of 2 m. The characteristic yield of this sintered ore is the particle size after dropping with respect to the mass (kg) of the sintered cake (lump) (except for upper light) before dropping: sintered ore (but upper light) of 5 mm or more. (without bedding ore)] is the ratio (mass%) of the mass (kg).

According to FIG. 2 and FIG. 3, it can be seen that when the melt penetration distance increases in the sintered raw material including a plurality of iron ores, the product yield and SI of the sintered ore are improved.

That is, these results are indicative of melt permeability of iron ore, and the method of adjusting the blending of each item of iron ore in the sintered raw material based on the melt permeation distance is to improve the product yield and strength of the sintered ore manufactured by the actual machine. It suggests that it is available for.

In addition, as shown to FIG. 2 and FIG. 3, in actual machine sintering operation, the intensity | strength SI of sintered ore is 90.5% or more, and the product yield is required 80.0% or more.

Next, in the present invention, the melt permeability of iron ore, i.e., required to improve the strength and the product yield of the sintered ore in the upper layer of the raw material filling layer (strength SI: 90.5% or more, product yield: 80.0% or more), that is, The appropriate range of the melt penetration distance measured in the melt permeability evaluation test is described.

In Table 1, the chemical composition of the iron ore of the main item mix | blended with a sintering raw material, and the melt penetration distance measured by the melt permeability evaluation test are shown.

In Table 1, B (a) and B (b) are two types of Brazilian ores, H (a) and H (b) are two types of Australian hematite ores, M (a) and M (b). Represents two types of Australian Maramamba ore. HP (a) and HP (b) are two types of Australian deceased ore, P (a) and P (b) are two types of Australian pisolite ore, HPM is a new Australian branded ore, I (a) and I ( b) represents two types of Indian ore. In addition, S1 and S2 represent the scale which arises in two types of steelmaking processes.

It is a figure which shows the comparison of the melt penetration distance of the iron ore of the main item shown in Table 1. FIG. According to Table 1 and FIG. 5, it can be seen that, among iron ores of the main items, the two kinds of Brazilian ores B (a) and B (b) have a high melt penetration distance of 4.0 mm or more.

On the other hand, two types of Australian hematite ores H (a) and H (b), two types of Australian deceased ore HP (a) and HP (b) and two types of Australian pisolite ore P (a) and P (b) It turns out that () has a low melt penetration distance as low as 2.0 mm or less.

In addition, Australian new brand ore HPM, two types of Australian Maramamba ore M (a), M (b) and two types of Indian ore I (a) and I (b) have a melt penetration distance of more than 2.0 mm to 4.0. It turns out that it exists in the range of less than mm.

In addition, Australian pisolite ores P (a) and P (b) have high crystal water content and are known as fusible iron ores that are easily assimilated and melted in the sintering reaction. However, it can be seen that the Australian penetrite ores P (a) and P (b) have a low melt penetration distance of 2.0 mm or less, which results in poor melt permeability. In addition, it turns out that the melt permeability distance of scales S1 and S2 which generate | occur | produce in a steelmaking process differs largely according to the kind of scale.

Next, the tablet firing test confirmed the effect of improving the strength and the product yield of the sintered ore in the case where they were selectively charged into the upper layer of the sintered raw material filling layer using plural items of iron ore having different melt permeability. .

As a sample for tablet plasticity test, the iron ore of several items shown in Table 1 is grind | pulverized, and it adjusts to the particle size which contains 50 mass% of iron ores with a particle diameter of 0.25-0.25 mm, and 50 mass% of iron ores with a particle diameter of 0.25 mm or less, These To each iron ore, 0.25 mm or less of limestone was mixed so that the CaO concentration was 10% by mass.

These samples were shape | molded by the tablet (porosity about 30%) of 4 mm in diameter and 10 mm in height using the metal mold | die shaping | molding die.

In the tablet firing test, the sample tablet was placed in a cylindrical ladle made of Ni having an inner diameter of 20 mm and a height of 15 mm, and fired in an air stream in an electric furnace. The baking conditions of a tablet use the sintered heat pattern similar to a real machine. In other words, the tablet was heated from 1100 ° C to 1290 ° C (highest temperature) in 1 minute, and then cooled from 1290 ° C to 1100 ° C in 3 minutes, and the tablet was immediately taken out of the furnace and air cooled.

For the strength evaluation of the calcined tablet after calcining, a drop test was performed in which 300 g of iron weights were dropped three times for one calcined tablet. After mixing the sample (plastic tablet) after this test, it classified into 0.5 mm sieve. As a strength index (+0.5 mm% value), the mass percentage of the 0.5 mm or more sample with respect to the mass of all the samples was calculated | required.

In the actual machine sintering operation, the strength SI of the sintered ore is 90.5% or more, and the product yield is required to be 80.0% or more.

In order to determine the evaluation criteria of the strength of the calcined tablet, a sintered ore having a strength SI of 90.5% or more and a yield of 80.0% or more produced in a practical sintering operation in advance was sampled, and the drop test was performed. In this drop test, a sample processed in the same shape as the tablet for ladle testing, that is, a tablet shape having a diameter of 8 mm and a height of 10 mm was used. The strength index (+0.5 mm% value) measured by this drop test was made into the evaluation criteria.

Moreover, the intensity | strength index (+0.5 mm% value) measured by the said drop test using the sintered ore whose strength SI manufactured by the actual machine sintering operation was 90.5% or more, and a yield of 80.0% or more was 88%. Therefore, in the strength evaluation of a baking tablet, the baking tablet which satisfy | fills 88% or more of the intensity | strength index (+0.5 mm% value) of the said drop test evaluated that the intensity and the yield of a sintered ore were favorable.

6 shows the relationship between the melt penetration distance of each item iron ore by the tablet plastic test and the strength index (+0.5 mm% value) by the drop test.

As shown in FIG. 6, in order to achieve the strength index (+0.5 mm% value) of the said drop test corresponding to the target sintered ore intensity (SI is 90.5% or more) in actual sintering operation, melt penetration distance Melt permeability of 4.0 mm or more is required.

Specific examples of iron ore items having melt permeability having a melt penetration distance of 4.0 mm or more include, for example, Brazilian ores B (a) and B (b) shown in Table 1.

In this invention, in order to improve the intensity | strength of a sintered ore of the upper layer of a sintering raw material filling layer, and a product yield (strength SI is 90.5% or more, and a product yield is 80.0% or more), melt permeation | transmits into the upper layer of the predetermined range of a sintering raw material filling layer. The iron ore which consists of 1 or more types is charged so that a distance may be 4.0 mm or more.

As described above, when the iron ore charged into the upper layer of the predetermined range of the sintered raw material filling layer contains iron ore of two or more kinds of items, the weight of the melt penetration distance of the iron ore of each item measured by the melt permeability evaluation test The mixing ratio of iron ores of two or more kinds of items is adjusted so that the average value is 4.0 mm or more.

Below, the iron ore which consists of 1 or more types selected or mix | blended so that melt penetration distance will be 4.0 mm or more is defined as high melt permeability iron ore.

7 shows the relationship between the thickness ratio of the upper charged layer in which the high melt permeable iron ore is charged and the strength SI of the sintered ore. Similarly, Fig. 8 shows the relationship between the upper charge layer thickness ratio and the yield of the sintered ore.

SI, which is an index indicating the strength of the sintered ore, is measured by collecting 10 kg of sintered ore having a particle diameter of 10 to 25 mm from the sintered ore after the following property yield measurement, and dropping it four times from a height of 2 m. This SI shows the ratio (mass%) of the mass (kg) of the sintered ore: 5 mm or more of particle diameter after a fall with respect to the mass (kg) of the sintered ore before falling.

The product yield of the sintered ore is measured by dropping the sintered cake (lump) five times from a height of 2 m. The product yield of this sintered ore is the mass of sintered ore (except the upper light) of 5 mm or more after dropping with respect to the mass (kg) of the sintered cake (lump) (except for the upper light) before the drop. The ratio (mass%) of (kg) is shown.

7 and 8 are each filled with a high melt permeable iron ore and other iron ores in the upper layer (part A) and the lower layer (part B) of the sintered ladle having a height of 600 mm and a diameter of 300 mm shown in FIG. 12, respectively. The test result in the case of baking is shown. In addition, limestone, coke, and semi-gloss are set at an average value of the upper layer (A layer) and lower layer (B layer) so as to be constant at 5.01 mass% of SiO ₂ , CaO / SiO ₂ : 1.89, and 4.3 mass% of coke in the sintered raw material. I combine it. These sintering raw materials are used after granulating by granulation water: 7.0 mass%. Here, another iron ore means iron ore except the iron ore charged in the upper layer.

The baking conditions of this sintering ladle test were layer thickness: 600 mm, suction negative pressure: 14.7 KPa, and baking time: 27 minutes.

The intensity | strength and the characteristic yield of the sintered ore in this sintering ladle test were evaluated based on the intensity SI of the sintered ore: 77% and the characteristic yield: 76%. These evaluation criteria use this sintering ray using the sintering raw material of the compounding conditions shown in Table 2 which confirms that the strength SI of sintered ore is 90.5% or more and a product yield is 80.0% or more when it carries out actual sintering operation. It was obtained by these tests. Therefore, these evaluation criteria correspond to intensity | strength SI (90.5% or more) and property yield (80.0% or more) of the sintered ore aimed at actual sintering operation.

That is, in the present sintered ladle test, when the strength SI of the sintered ore was 77% or more and the product yield was 76% or more, the strength and the product yield of the sintered ore were evaluated to be good.

As shown to FIG. 7 and FIG. 8, in order to achieve the intensity | strength SI of sintered ore of the said sintering ladle test of 77% or more, and the yield of product of 76% or more, the upper loading layer thickness ratio which loads high melt permeability iron ore (raw material) The layer thickness ratio with respect to the total layer thickness of the filling layer upper layer) needs to be 5 to 12% of range.

When the ratio of the upper loading layer thickness to charge high melt permeability iron ore is lower than 5%, the effect of improving the yield, strength and production rate of the sintered ore in the upper layer of the raw material filling layer by selective charging of iron ore excellent in melt permeability, You won't get enough.

When the ratio of the upper charge layer thickness to charge the high melt permeability iron ore is higher than 12%, as described later, the iron ore having high melt permeability is low in granulation, and the pseudo particles collapse at the time of charging the sintering machine and during the firing process, Air permeability in a raw material filling layer tends to fall. Therefore, the sinterability of the whole raw material filling layer deteriorates, and the product yield, strength, and production rate of a sintered ore deteriorate.

In addition, iron ore having high melt permeability is an ore having a low Al ₂ O ₃ content and a relatively high price, as will be described later. Therefore, it becomes the cause which raises the manufacturing cost of sintered ore.

For the above reasons, in order to sufficiently improve the property yield and strength of the upper layer of the raw material filling layer without lowering the air permeability of the entire raw material filling layer (strength SI of 90.5% or more, the product yield of 80.0% or more), a plurality of items of iron ore The high melt permeable iron ore selected or blended so that the weighted average value of the melt penetration distance is 4.0 mm or more is charged from the upper surface of the raw material filling layer into the upper layer in the range of 5 to 12% in the layer thickness ratio to the total layer thickness. Then, other iron ores were charged into the lower layer of the raw material filling layer, and additional raw materials, solid fuels, and semi-ores were charged into the upper and lower layers of the raw material filling layer. In addition, unless otherwise indicated, the compounding ratio of a subsidiary material, a solid fuel, and semi-glossy is the same in the upper layer and lower layer of a raw material filling layer.

In addition, the scales S1 and S2 generated in the steelmaking process may also be charged in the upper layer in the range of 5 to 12% of the upper loading layer thickness ratio as the iron-containing raw material in addition to the high melt permeable iron ore. Similarly, the scales S1 and S2 may be charged to the lower layer as an iron-containing raw material in addition to other iron ores. Hereinafter, only the high melt permeability iron ore or the iron containing raw material which combined the high melt permeability iron ore and the scale as a high melt permeability iron containing raw material. In addition, only iron ore or the iron containing raw material which combined the scale with other iron ores is used as another iron containing raw material.

9 shows the relationship between the melt penetration distance of the iron ore of each item and the Al ₂ O ₃ content. As shown in Fig. 9, the melt penetration distance and the Al ₂ O ₃ content are correlated, and the iron ore having a melt penetration distance of 4.0 mm or more is preferably selected from an iron ore item having an Al ₂ O ₃ content of 0.6% by mass or less. Do.

The melt permeability of iron ore is not determined solely from the content of Al ₂ O _3, but is also affected by structures such as pores of iron ore. However, the higher the Al ₂ O ₃ content in the iron ore and produce Al ₂ O ₃ content is also increased in the moving picture to be melt. For this reason, the viscosity of the melt increases, and the melt permeability decreases.

Therefore, in the present invention, the melt penetration distance that the upper layer of the raw material charged into the packed bed: 4.0㎜ or more iron ore is preferably Al ₂ O ₃ content is less than 0.6% by mass.

In addition, as described above, in order to maintain the air permeability of the entire raw material filling layer, it is necessary to prevent excessive increase in the melt of the upper layer of the raw material filling layer. In addition, in order to reduce costs, it is preferable to reduce side materials. Therefore, the effect of the ratio in the upper layer of the subsidiary material, especially limestone, required for the formation of the melt was investigated.

10 shows the relationship between the limestone ratio in the upper layer and the product yield of the sintered ore in the sintering ladle test. 11 shows the relationship between the ratio of limestone in the upper layer and the intensity SI of the sintered ore in the sintering ladle test. In the Example of this invention, the brazing ore B (b) was used as the high melt permeability iron ore in the upper layer, and the upper charge layer thickness ratio was 11.7%. In addition, the sintering raw material of the mixing | blending ratio shown in Table 2 was used.

As shown in FIG. 10, FIG. 11, SI and product yield were improved by using high melt permeability iron ore as iron ore in an upper layer. In addition, by decreasing the ratio of limestone in the upper layer, the SI and property yields increased.

Therefore, it is preferable that the mixing | blending ratio of the upper raw material becomes below the mixing | blending ratio of the lower raw material from a viewpoint of cost reduction with respect to the auxiliary raw material charged to a raw material filling layer.

In the present invention, the method of charging the high melt permeable iron-containing raw material and other iron-containing raw materials into the upper layer of the raw material filling layer on the sintered pallet and the lower layer of the raw material filling layer, respectively, is not particularly limited. The method shown in FIG.

The first surge hopper (for other iron-containing raw materials) 1 and the second surge hopper (for high melt permeable iron-containing raw materials) (2) are arranged in series in the device length direction in the light-emitting portion of the downward suction type sintering machine. It is arranged. From this first surge hopper 1, other iron-containing raw materials other than the high melt permeable iron-containing raw material, and a sintered raw material 3 composed of limestone, coke and semi-glossy are charged onto the sintered pallet 4 to prepare a raw material. The lower layer 5 of the filling layer is formed. Thereafter, a high melt permeable iron-containing raw material and a sintered raw material 6 composed of limestone, coke and semi-glossy were charged from the second surge hopper 2, and the upper layer 7 of the raw material filling layer was placed on the lower layer 5. ) Can be formed.

In addition, the high melt permeable iron-containing raw material, the sintered raw material 6 composed of limestone, coke and semi-glossy and other iron-containing raw materials, and the sintered raw material 3 composed of limestone, coke and semi-glossy are respectively drum mixers and fan pellets. It is mixed and granulated using granulators 8 and 9 such as a pan pelletizer to obtain pseudo particles. Thereafter, each of the sintered raw materials is supplied to the second surge hopper (for high melt permeable iron-containing raw material) 2 and the first surge hopper (for other iron-containing raw material) 1.

Further, the high melt permeable iron-containing raw material, the sintered raw material 6 composed of limestone, coke and semi-ore, and the other iron-containing raw material, and the sintered raw material 3 composed of limestone, coke and semi-glossy are limestone, It mix | blends so that coke and semi-glossy may become predetermined | prescribed compounding ratio.

[First Embodiment]

Below, the effect of this invention is demonstrated to an Example.

As a sintering raw material, the sintering ladle test was done using the sintering ladle of 600 mm in height and 300 mm in diameter shown in FIG. 12 based on the average mixing conditions at the time of actual operation shown in Table 2. As shown in FIG.

Moreover, when actual sintering operation is performed using the sintering raw material of the mixing | blending conditions shown in Table 2, it confirms beforehand that the sintered ore of 90.5% or more of intensity | strength SI and 80.0% or more of product yield is obtained.

In addition, the production rate in the sintering ladle test, the product yield of the obtained sintered ore, the cold strength SI, the reduction reduction index RDI, and the reduction rate JIS-RI (%) were measured. The results are shown in Table 3 together with the production conditions. In addition, a production rate shows the particle size: the mass (t) of 5 mm or more of sintered ores except for upper light divided by ladle area (m <2>) and sintering time (day).

The intensity | strength SI of a sintered ore is measured by taking out 10 kg of sintered ores with a particle diameter of 10-25 mm from the sintered ore after the following characteristic yield measurement, and falling four times from a height of 2 m. This SI shows the ratio (mass%) of the mass (kg) of the sintered ore: 5 mm or more of particle diameter after a fall with respect to the mass (kg) of the sintered ore before falling.

The yield of the sintered ore is measured by dropping the sintered cake (lump) five times from a height of 2 m. The product yield of this sintered ore is the mass of the sintered ore (but not the upper light) of 5 mm or more after dropping with respect to the mass (kg) of the sintered cake (lump) (except for the upper light) before the drop. The ratio (mass%) of (kg) is shown.

The reduction reduction index (RDI) of the sintered ore was measured in accordance with the test method specified in JIS M 8720. That is, the particle size of between 15 and collected in a sintered ore 500g _{19㎜, N 2: 70%,} CO: is reduced at 550 ℃ in a 30% mixture gas for 30 minutes. Then, the reduced sintered ore is charged to a drum and 900 rotation tests are performed in 30 minutes. The ratio (mass%) of the mass (g) of the sintered ore powder of the particle size after rotation: 3 mm or less with respect to the mass (g) of the sintered ore after reduction before rotation is a reduction reduction differentiation index (RDI).

JIS reduction rate (JIS-RI) of the sintered ore was measured in accordance with the test method specified in JIS M 8713. That is, particle size: 19 to collected the sintered ore 500g of _{21㎜, N 2: 70%,} CO: and at 900 ℃ from a 30% reducing gas mixture for 180 minutes. The ratio (mass%) of the decrease (g) of the mass (g) of the mass of sintered ore by reduction with respect to the mass (g) of oxygen contained in iron oxide of the sintered ore before reduction is JIS reduction rate (JIS-RI).

The high melt permeable iron-containing raw material charged into the upper layer of the raw material filling layer was mixed with limestone, semi-glossy, and coke to form granules by granulation, and charged into Part A (upper layer of the raw material filling layer) shown in FIG. 12. In addition, the compounding ratio of limestone, coke, and semi-glossy is the same as the compounding ratio in the whole charged raw material.

In addition, the other iron-containing raw material was mixed with limestone, semi-glossy, and coke in the same manner as above to form a pseudo particle by granulating, and charged into B portion (lower layer of the raw material filling layer) shown in FIG. 12. The ratios of coke, limestone (CaO), and semiglow in the A and B portions of the sintered raw material filling layer are equivalent.

In addition, the high melt permeability iron-containing raw material for charging in the A part includes two kinds of Brazilian ores B (a) and B (b) having different melt penetration distances shown in Table 1 and two kinds having different melt penetration distances. Australian pisoleite ores P (a) and P (b) and iron ore blends thereof and Australian new brand ore HPM, as well as scales S1 and S2 generated from two types of steelmaking processes with different melt penetration distances.

In this example, B part is charged 530 mm from the great surface of the sintered pallet, and A part is charged on the B part with a layer thickness of 70 mm (layer thickness ratio to total layer thickness (600 mm: 11.7%)). It was.

In addition, SiO ₂ : 5.01 mass%, CaO / SiO ₂ : 1.89, coke blending: 4.3 mass% (each is the same as the ratio of the whole sintering raw material) in the compounding raw material of A part and B part, and made granulation conditions constant. And granulation water: 7.0 mass%. In addition, the baking conditions of this sintering ladle test were layer thickness: 600 mm, suction negative pressure: 14.7 KPa, and baking time: 27 minutes. Each test result shown in Table 3 is an average of n = 2 measurements.

The 1st reference example is the base test which uniformly charged the iron ore of several items shown in Table 2 as a sintering raw material uniformly in the filler layer thickness direction. Evaluation of the intensity | strength SI of the sintered ore of the Example and the comparative example shown below, a yield of a product, a yield, etc. were evaluated based on the 1st reference example.

The first embodiment selectively charges the Brazilian ore B (a) having a melt penetration distance of 4.65 mm shown in Table 1 to the A part (upper layer of the raw material filling layer), and the remaining iron-containing raw material (other iron-containing material). It is an example which charged the raw material to B part (lower layer of a raw material filling layer).

The 2nd Example is an example in which the Brazilian ore B (b) of 4.22 mm melt penetration distance shown in Table 1 was selectively charged to A part, and the remaining iron containing raw material was charged to B part.

In the first and second embodiments, the yield and strength SI of the sintered ore were improved and the production rate was improved as compared with the first reference example without impairing the reduction resistance RDI and the reduction rate JIS-RI. .

In the third embodiment, a Brazilian ore B (a) having a melt penetration distance of 4.65 mm and a Australian pisoleite ore P (a) having a melt penetration distance of 1.12 mm are shown in Table 1. The mixing ratio P (a): It mixes so that it may become B (a) = 15: 85, it selectively loads in A part, and loads the remaining iron containing raw material in B part.

The weighted average value of the melt penetration distance of the mixture of the iron ore of B (a) and P (a) selectively charged in the A part of Example 3 by the mixing ratio of each melt penetration distance of B (a) and P (a) ] Was 4.12 mm. Therefore, the product yield and strength SI of the sintered ore were improved compared with the first reference example, and the production rate was improved, without impairing the reduction resistance RDI and the reduction rate JIS-RI.

In the fourth embodiment, a Brazilian ore B (a) having a melt penetration distance of 4.65 mm and a scale S1 generated in a steelmaking process having a melt penetration distance of 4.21 mm are shown in Table 1. The mixing ratio B (a): S = It mixes so that it may become 85:15, selectively loads in A part, and loads the remaining iron containing raw material in B part.

In Example 5, Brazilian Ore B (a) having a melt penetration distance of 4.65 mm shown in Table 1 and a scale S2 generated in a steelmaking process having a melt penetration distance of 1.66 mm are mixed ratios B (a): S2 = It mixes so that it may become 85:15, selectively loads in A part, and loads the remaining iron containing raw material in B part.

The melt penetration distance (weighted average value by the mixing ratio of B (a) and each melt penetration distance of S1) of the mixture of B (a) and S1 iron ore which were selectively loaded into the A part of Example 4 was 4.28 mm. Therefore, compared with the 1st reference example, the product yield and intensity | strength SI of the sintered ore improved, and the production rate improved, without damaging the reduction-differentiation RDI and the reduction rate JIS-RI.

In addition, the melt penetration distance (weighted average value by the mixing ratio of each melt penetration distance of B (a) and S2) of the mixture of B (a) and S2 iron ore selectively loaded into the A part of Example 5 is 4.28 mm. It was. Therefore, compared with the 1st reference example, the product yield and intensity | strength SI of the sintered ore improved, and the production rate improved, without damaging the reduction-differentiation RDI and the reduction rate JIS-RI.

On the other hand, in the first comparative example, Brazilian ore B (b) having a melt penetration distance of 4.22 mm shown in Table 1 and Australian pysolelite ore P (b) having a melt penetration distance of 1.23 mm were mixed in a ratio P (b). ): B (b) is mixed so as to be 45:55, and selectively charged into the A portion, and the remaining iron-containing raw material is charged into the B portion.

Melt penetration distance of the mixture of iron ore of B (b) and P (b) selectively charged in Part A of the first comparative example [weighted average value by the mixing ratio of each melt penetration distance of B (b) and P (b)] Was as low as 2.87 mm. Therefore, compared with the 1st reference example, the product yield and intensity | strength SI of sintered ore fell, and the production rate also fell.

A 2nd comparative example is the example which melt | dissolved Australian pysolelite ore P (a) of melt penetration distance shown in Table 1 by 1.12 mm selectively to A part, and the remaining iron containing raw material was charged to B part.

The third comparative example is an example in which an Australian pisoleite ore P (b) having a melt penetration distance of 1.23 mm shown in Table 1 is selectively charged in A part, and the remaining iron-containing raw material is charged in B part.

In both the second comparative example and the third comparative example, the melt penetration distances of the iron ores of P (a) and P (b) selectively loaded into the A portion were low at 1.12 mm and 1.23 mm, respectively. Therefore, compared with the 1st reference example, the product yield and intensity | strength SI of sintered ore fell, and the production rate also fell.

Second Embodiment

Next, the upper loading layer thickness ratio (upper part) of Brazilian ore B (a) charged in Part A (upper layer of raw material filling layer) under the same conditions as in the first embodiment, which was carried out in [First Embodiment]. Except for the layer thickness ratio with respect to the total layer thickness from the surface), the same conditions were used, and only the upper charged layer thickness ratio was changed and the test was performed similarly. In addition, a 1st reference example is the same conditions as that of [1st Example].

In addition, similarly to [Example 1], the production rate in the sintered ladle test, the product yield of the obtained sintered ore, and the cold strength SI were measured. The results are shown in Table 4.

The first to third embodiments in which Brazilian ore B (a) is charged in the A portion such that the upper loading layer thickness ratio is in the range of 5 to 12%, impairs the reduction resistance RDI and the reduction rate JIS-RI. In comparison with the first reference example, the product yield and strength SI of the sintered ore were improved, and the production rate was improved.

On the other hand, the first and second comparative examples in which the Brazilian ore B (a) is charged in the A portion so that the upper charging layer thickness ratio is less than 5% are included in the upper loading layer thickness ratio. In the case of the 3rd, 4th comparative example charged to A-part so that it might become more than this 12%, the product yield and intensity | strength SI of sintered ore fell and the production rate also fell compared with the 1st reference example.

As mentioned above, according to this invention, in the manufacturing method of the sintered ore using a downward suction type sintering machine, melt permeability to the fine part of iron ore of each item mix | blended with a sintering raw material is evaluated, and based on this evaluation result, By selecting iron ore of an item having excellent melt permeability into the finely divided portion among each iron ore and selectively charging the upper layer of the raw material filling layer, the product yield and strength of the upper layer of the raw material filling layer are improved, and the productivity of the sintered ore is improved. You can. Therefore, the present invention is highly applicable to the steel industry.

1: 1st surge hopper (for other iron containing raw materials)
2: 2nd surge hopper (for high melt permeability iron containing raw material)
3: sintered raw material consisting of other iron-containing raw materials, secondary raw materials, coke and semi-ore
4: sintered pallet
5: lower layer of raw material filling layer
6: sintered raw material consisting of high melt permeable iron-containing raw material, secondary raw material, coke and semi-ore
7: upper layer of raw material filling layer
8: assembly machine
9: assembling machine

Claims (7)

It is a manufacturing method of a sintered ore which mixes iron-containing raw material containing a plurality of items of iron ore, a subsidiary material, a solid fuel, and a semi-ore, and makes it a sintering raw material, mixes and granulates these sintering raw materials, loads it on a sintering pallet, and bakes,
Based on the melt penetration distance measured for each item of the iron ore, from the iron ore of the plurality of items, a high melt permeable iron ore selected or blended such that the weighted average value of the melt penetration distance is 4.0 mm or more is formed on the sintered pallet. Charged to the upper layer in the range of 5 to 12% in a layer thickness ratio with respect to the total layer thickness from the upper surface of the raw material filling layer formed on the
Other iron ore is charged to the lower layer of the raw material filling layer,
Moreover, the said subsidiary material, the said solid fuel, and the said semiglow are charged to the said upper layer and the said lower layer of the said raw material filling layer, The manufacturing method of the sintered ore characterized by the above-mentioned. The Al ₂ O ₃ content of the said high melt permeable iron ore is 0.6 mass% or less, The manufacturing method of the sintered ore of Claim 1 characterized by the above-mentioned. The method according to claim 1, wherein in addition to the high melt permeable iron ore, the scale generated in the steelmaking process as the iron-containing raw material is 5 to 12% in a layer thickness ratio with respect to the total layer thickness from the upper surface of the raw material filling layer. It charges to the upper layer of the range, The manufacturing method of the sintered ore characterized by the above-mentioned. The method for producing a sintered ore according to claim 1, wherein the solid fuel and the semi-glossy are charged at the same compounding ratio in the upper layer and the lower layer of the raw material filling layer. The manufacturing method of the sintered ore according to claim 1, wherein the mixing ratio of the upper layer is equal to or less than the mixing ratio of the lower layer with respect to the sub-raw material charged into the raw material filling layer. The said high melt permeability iron ore and the said other iron ore mix, mix and assemble the said subsidiary material, the said solid fuel, and the said semi-ore, respectively, in the said upper layer and the said lower layer of the said raw material filling layer, respectively. Charging, The manufacturing method of a sintered ore characterized by the above-mentioned. The said high melt permeability iron ore mixes the said scale which arose in the said iron-making process as said iron containing raw material, mix | blended the said subsidiary material, the said solid fuel, and the said semi-ore, mixed and assembled, A method for producing a sintered ore, characterized in that it is charged into the upper layer of the raw material filling layer.

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