JP6988778B2 - Manufacturing method of charcoal interior sinter and equipment for manufacturing charcoal interior sinter - Google Patents

Description

The present invention relates to a technique for producing a sinter used as a raw material for iron making in a blast furnace or the like, and specifically, a method and a method for producing a sinter using a carbonaceous material interior molded body as a raw material for sinter. It is about equipment.

Currently, the blast furnace ironmaking method mainly uses iron-containing raw materials such as iron ore and sinter as an iron source. _{Here, the sinter is an auxiliary raw material composed of a SiO 2-} containing raw material such as silicate, serpentine, and refined nickel slag, and a CaO-containing raw material such as limestone and fresh lime, in addition to iron ore having a particle size of 10 mm or less. , Sintering, which is a pseudo-particle, is obtained by adding an appropriate amount of water to a granulation raw material made of solid fuel (carbonate), which is a coagulant made of powdered coke or smokeless charcoal, and mixing and granulating using a drum mixer or the like. After the raw material is used, the sintered raw material is charged onto a pallet that circulates and moves in the sintering machine, and the carbonaceous material contained in the pseudo-particles is burned to be sintered, and the obtained sintered cake is crushed. It is a kind of agglomerate ore that has been sintered and recovered as a product with a certain particle size or more.

By the way, in recent years, as the above-mentioned agglomerate ore, an iron source such as iron ore and dust and a charcoal material such as coke placed in close proximity to each other have been attracting attention. The reason is that, for example, when an iron source such as iron ore and a carbonaceous material are placed close to each other in one agglomerate ore, a reduction reaction (exothermic reaction) on the iron source side and a gasification reaction (endothermic reaction) on the carbonaceous material side are performed. This is because iron-making efficiency is improved and the temperature inside a blast furnace or the like can be lowered because) and the above occur repeatedly at a high speed.

The granulation ore is, for example, the interior of a carbonaceous material for producing a sintered ore, which is a pseudo particle formed by forming an outer layer composed of iron ore powder and a CaO-containing raw material around a carbonaceous material core disclosed in Patent Document 1. When the sintering raw material obtained by mixing the granulated particles with the normal granulated particles is charged onto the pallet of the sintering machine to form the charging layer, the above-mentioned carbonaceous material interior granulated particles are charged into the charging layer. There is a carbonaceous interior sintered ore that is charged in a large amount on the lower layer side and produces a sintered ore by the combustion heat of the carbonaceous material contained in the above-mentioned ordinary granulated particles.

In this technique, coke particles having a particle size of 3 mm or more are used for the carbonaceous material core as the carbonaceous material interior granulated particles, and a pellet feed having an adjusted particle size is used for the iron ore powder. Further, only a method of granulating granulated particles with a drum mixer or a pelletizer is disclosed.

Japanese Patent No. 5790966

However, in the method of Patent Document 1, there is a limitation on the particle size of the pellet feed and the carbonaceous material, which are the raw materials of the carbonaceous material interior granulated particles.
In order to use pellet feeds whose particle size is adjusted to a specific range, control the particle size distribution of pellet feeds on the market and sizing and removing undersized and oversized particles as necessary. It was necessary to remove the coarse particles by crushing or crushing. On the other hand, the particle size is 3
In order to use coke particles of mm or larger, it is common to sort coke with a 3 mm sieve. However, since coke is usually handled outdoors, it is in a humidity-controlled state. When it is attempted to sort such a humidity control raw material with a sieve of 3 mm, there is a problem that it is difficult to obtain a required amount because powder adheres to the mesh and the sieving efficiency is significantly lowered.

Therefore, the present invention has been made in view of the above-mentioned problems of the prior art, and an object thereof is to relax the restrictions on the particle size of the raw material and obtain high-strength carbonaceous material interior particles. The purpose is to propose a method for producing high quality carbonaceous interior sintered ore. At the same time, it is to provide manufacturing equipment suitable for the method.

As a result of diligent studies to solve the above-mentioned problems, the inventors have found that it is effective to form carbonaceous interior molded particles by molding by applying an external force, and the present invention has been made. Has led to the development of. That is, the present invention first comprises iron ore powder, a CaO-containing raw material, and a carbonaceous material, and compression-molded carbonaceous material interior molded particles for sinter ore production are mixed with raw material particles for sinter ore production. When the sinter raw material is charged onto the pallet of the sinter to form the charging layer, a large amount of the carbonaceous material interior molding particles are charged to the lower layer side of the charging layer to produce the sinter. We propose a method for producing a sinter inside a sinter, which is characterized by producing a sinter using the heat of combustion of the sinter contained in the raw material particles.

Regarding the method for producing the carbonaceous interior sinter according to the present invention,
a. The raw material particles for sinter production have a particle size smaller than that of the carbonaceous interior molded particles granulated by a drum mixer.
b. The iron ore powder is a powdered iron ore having a particle size of 1 mm or less.
c. The range from the outer surface of the carbonaceous material interior molded particles to 2 mm has a melting point of 1200 ° C. or higher and 1500 ° C. or lower.
d. The above charcoal material must be coke particles having a particle size of 8 mm or less.
e. The grain size of the above-mentioned charcoal interior molded particles is 8 mm or more.
f. The above-mentioned charcoal material interior molded particles are a molded body obtained by molding iron ore powder, a CaO-containing raw material as a melting point adjuster, and charcoal material using a compression molding machine.
Can be a more preferred solution.

Secondly, the present invention is the equipment used for the method for producing any of the above-mentioned sinters for interior sinter, which is a hopper that holds iron ore powder, a hopper that holds CaO-containing raw materials, and charcoal. At least one hopper for holding the material is provided, and at least one of the iron ore powder, the CaO-containing raw material, and the raw material containing the charcoal material are mixed, compressed, and molded to form the sinter-manufacturing charcoal material interior molded particles. A compression molding machine for sintering, a drum mixer that granulates a normal raw material for sinter to be used as raw material particles for sinter production, and the carbonaceous material interior molding particles and the raw material particles for sinter production are mixed. A charcoal having a surge hopper held as a sinter raw material and provided with a dwitroid type sinter machine that sinters the sintered raw material charged from the surge hopper into a sinter ore. We provide manufacturing equipment for timber interior sinter.

According to the present invention, it is possible to mold high-strength carbonaceous material interior molded particles without worrying about the particle size of the carbonaceous material or iron ore powder used. In particular, since the sinter can be produced from the carbonaceous interior molded particles using a general Dwightroid type (DL) sinter, it is possible to produce the carbonaceous interior sinter in a large amount and at low cost. Will be possible. Further, the carbonaceous material interior sinter of the present invention has sufficient strength for use as a raw material for a blast furnace or the like, and also has a structure in which an iron-containing raw material and a carbonaceous material are closely arranged, so that the iron-making reaction can be carried out. It improves the reaction efficiency, lowers the temperature inside the furnace, reduces the fuel ratio, and contributes to the reduction of manufacturing costs.

It is a conceptual diagram of the charcoal material interior molding particle (A) which shows one Embodiment of this invention, and the charcoal material interior granulation particle (B) which concerns on the prior art. It is a manufacturing equipment conceptual diagram (A) which shows one Embodiment of this invention, and is a manufacturing equipment conceptual diagram (B) of the prior art.

FIG. 1 shows a conceptual diagram of a charcoal interior molded particle (A) showing an embodiment of the present invention and a charcoal interior granulated particle (B) according to the prior art described in Patent Document 1. As shown in FIG. 1A, the carbonaceous material interior molded particles 1 of the present invention have a structure in which the carbonaceous material 2 is dispersed in the mixed phase 3 of the iron ore powder and the CaO-containing raw material by compression molding. For compression molding, a double roll type, a flat plate type briquette machine, a cylinder press type, or the like can be used. FIG. 4 in the figure is a sintered interface showing the boundary between the residual carbonaceous material region (nucleus) and the vanishing carbonaceous material region (outer layer) after sintering, which will be described later. On the other hand, the one shown in FIG. 1B is a conventional technique for granulating a material having a mixed phase 3 of iron ore powder and a CaO-containing raw material as an outer layer containing no carbon material around two cores of carbon material having a size of 3 mm or more. The charcoal material interior granulated particles 5 are obtained.

According to conventional general knowledge, it is known that if the coating layer thickness from the carbonaceous material 2 to the surface of the molded body is 2 mm or more, the carbonaceous material 2 can be prevented from burning or disappearing in the sintering process. In this respect, in the carbonaceous material interior molded particles of the present invention, as is clear from FIG. 1A, the carbonaceous material 2 is also distributed in the vicinity of the surface layer, and voids are generated due to combustion and disappearance in the sintering step. However, there is a sound residual area of carbonaceous material even after sintering. Further, in the case of the present invention, a molded body having sufficient hot strength is obtained in spite of such voids. It is considered that the reason is that since the molded body is obtained by forcibly compressing, the decrease in hot strength due to the formation of voids can be compensated for.

Here, as the iron ore powder used in the present invention, it is preferable to use powdered iron ore having a particle size of 1 mm or less. Here, the particle size of 1 mm or less means that the entire amount of the sieve has a nominal opening of 1 mm specified in JIS Z8801-1: 2006.

If the particle size of the iron ore powder used in the present invention is within the above range, in addition to the pellet feed, a sinter feed, a mill scale, or a converter exhaust gas recovery dust containing a larger particle size of 10 μm or less than the pellet feed ( OG dust), tailing generated during mineral processing, and crushed products thereof may be used, or they may be mixed in a pellet feed. A mixture mainly composed of a pellet feed or a pellet feed is preferable. The pellet feed is a fine-grained ore having a diameter of 1 mm or less of 90% or more, and is excellent in that it is mainly composed of high-grade (high Fe, low gangue) hematite and magnetite, and can be obtained in large quantities at low cost.

However, the melting point of the above-mentioned magnetite, particularly high-grade magnetite, is as high as about 1580 ° C., which is much higher than the suitable sintering temperature (1200 to 1400 ° C.) for obtaining high-quality sinter, and is usually It does not melt at the sintering temperature of, that is, the sintering reaction does not occur.

In the present invention, the melting point of the mixed phase of iron ore and the CaO-containing raw material is lowered by adding a CaO-containing raw material which is a melting point adjusting agent to the iron ore powder, and the temperature at the time of sintering (1200 ° C. or higher) is early. By forming a fusion layer on the surface layer of the pseudo-particles and allowing the fusion layer to act as an oxygen blocking layer, the combustion and disappearance of the carbonaceous material dispersed inside the carbonaceous material interior molded particles is prevented. The feature is that the carbonaceous material remains.

Further, according to the present invention, by adopting the above structure, even if air invades during sinter firing, the residual carbonaceous material region (nucleus) can be present. Since, by oxygen blocking effect of the surface layer (outer layer) of the carbonaceous material decorated molding particles (pseudo particles), the carbonaceous material contained in than the inner nuclear sintered interface 4 does not reach intrusion O _2, the surface layer portion by the C intrusion O ₂ reaction, the outer layer is because it means that is held in the CO gas essentially reducing atmosphere, believed to residual carbonaceous material is possible.

Here, the melting point of the mixture of the iron ore and the melting point adjusting agent adjusted above is preferably in the range of 1200 to 1500 ° C, more preferably in the range of 1200 to 1400 ° C from the viewpoint of promoting melting on the sintering machine. be. This is because if the temperature is lower than 1200 ° C., no melt is formed, and calcium ferrite, which has the highest strength among the constituent minerals of the sinter and has a relatively high reducibility, is not formed. On the other hand, above 1500 ° C., it does not melt on the sinter and does not fuse with the sinter structure mainly composed of calcium ferrite.

The CaO-containing raw material to be added as a melting point adjuster is selected from quicklime (CaO), slaked lime (Ca (OH) ₂ ), calcium carbonate (CaCO ₃ ) and dolomite (CaMg (CO ₃ ) ₂ ). It is preferably composed of one kind or two or more kinds. In particular, CaO is preferable. The amount of CaO-containing raw material added is, in terms of CaO, to the pellet feed (PF) as iron ore powder used for the outer layer, which has a small amount of gangue components such as Anglo American-PF (hematite (Fe ₂ O ₃ )). When 97.7 mass%) is used, _{it may be determined from the Fe 2} O _3- CaO dual system state diagram. When iron ore powder having a large amount of gangue component is used, the amount added as the CaO component is determined by using the SiO _2- Fe ₂ O _{3- CaO ternary phase diagram considering the SiO 2 which is the gangue component.} You just have to decide. In addition to acting as a melting point adjusting agent, quicklime also acts as a binder.

In the present invention, it is preferable to adjust the water content to about 4 to 10 mass% from the viewpoint of improving moldability. The reason is that when the moisture content is 4 mass% or more, the strength after molding becomes higher, and when the moisture content is 10 mass% or less, molding defects can be further reduced.

Further, as the binder, pregelatinized starch, bentonite, polyvinyl alcohol, magnesium lignin sulfonate, polyacrylamide, CMC (carboxymethyl cellulose) and the like can be used. For example, it is preferable to add 0.1 to 10 mass% of pregelatinized starch. The reason is that when the pregelatinized starch is 0.1 mass% or more, the strength after molding increases further, and when it exceeds 10 mass%, the effect of increasing the strength after molding begins to saturate, which is not worth the increase in the addition cost. This is because there is a risk.

As the charcoal material, it is preferable to use a charcoal material having a low volatile content such as anthracite charcoal such as coke grains and Hongei charcoal. The particle size of the carbonaceous material is preferably 8 mm or less. Here, the particle size of 8 mm or less means that the entire amount of the sieve has a nominal opening of 8 mm specified in JIS Z8801-1: 2006. In the conventional method, one carbonaceous material core is always required for one granulated particle, so that it is necessary to trim the coke to a particle size of 3 mm or more. Since it is effective if one or more carbonaceous particles are present in the layer (nucleus), the particle size is preferably 8 mm or less, and the lower limit is not limited. As a characteristic of compression molding, the center of the carbonaceous particles cannot exist closer to the outer surface of the molded particles than the radius of the carbonaceous particles. When it is present at 20% or more on a mass basis, it is more preferable because the ratio of the carbonaceous material that disappears at the time of sintering at a place within 1 to 2 mm from the outer surface of the molded particles is reduced and the strength is improved. Here, when the particle size exceeds 2.8 mm, it means that the sieve does not pass through the sieve having a nominal opening of 2.8 mm defined in JIS Z8801-1: 2006. More preferably, the arithmetic mean particle size is in the range of 1.5 mm or more and 4.0 mm or less.

Further, in the region where the carbonaceous material burns and disappears after sintering, the thickness of the outer layer of the pseudo-particles is preferably 2 mm or more at the thinnest point. The reason is that if it is less than 2 mm, the hot strength of the molded particles may decrease due to the voids in the carbonaceous material that have disappeared. Normally, in compression molding, the thickness from the surface layer of the molded particles to the sintered boundary layer is not uniform because the density other than the compression direction varies and the shape does not become a true sphere. Since the hot strength of the sintered layer is considered to be proportional to the thickness of the sintered layer, the evaluation is made based on the thinnest portion of the outer layer. Since the molded particles are usually heated from the outside, it is difficult to raise the temperature toward the center side during heating. Therefore, in order to increase the thickness of the outer layer, the melting point of the outer layer can be adjusted to a lower value or the compressive force can be adjusted to a lower value. The thickness of the outer layer is more preferably in the range of 3 to 7 mm from the viewpoint of oxygen blocking and hot strength.

Further, the particle size of the carbonaceous material interior molded particles (pseudo-particles) of the present invention is 7 mm from the total of the minimum value of the sphere equivalent diameter of the carbon material residual region (nucleus) and the minimum value of the outer layer. However, from the viewpoint of suppressing the reaction of the carbonaceous material on the sintering machine, considering the temperature distribution in the molded particles, the particle size should be sufficiently raised to the center of the particles in the sintering process, that is, 8 mm or more. It is preferable to do. It is more preferably 10 mm or more, still more preferably 20 mm or more. Here, the particle size is the equivalent diameter of a sphere.

Further, the carbonaceous material interior molded particles of the present invention are required to be segregated and charged into the lower layer side of the sintering layer when the sintering raw material is charged into the sintering machine described later. Therefore, a normal sintering raw material is required. It is preferable to make the particle size larger than that of (granulated particles). Here, the above-mentioned ordinary granulated particles are made of an auxiliary raw material including iron ore powder, carbonaceous material, and a CaO-containing raw material as a granulated raw material, and the particles have a diameter of 2 to 4 mm (arithmetic average diameter) by a drum mixer, a pelletizer, or the like. Pseudo-particles granulated to a diameter (hereinafter referred to as the same). Further, the particle size of the granulated particles in the present invention means the particle size measured by sieving.

Next, the carbonaceous interior molded particles of the present invention and a method for producing a sinter using the molded particles as a sinter raw material will be described.
FIG. 2A shows an example of a method for producing a carbonaceous interior sintered ore using carbonaceous interior molded particles conforming to the present invention. On the other hand, FIG. 2B shows an example of a method for producing a carbonaceous interior sintered ore using the carbonaceous interior granulated particles by the conventional method described in Patent Document 1. In the above example of FIG. 2A, iron ore powder 8 having a particle diameter of 1 mm or less, CaO-containing raw material 9 as a melting point adjusting agent, and a carbonaceous material (coke powder) 10 having a particle diameter of 8 mm or less are used in a compression molding machine. It is charged into a certain briquette machine 11 and compressed-molded into carbonaceous interior molded particles (pseudo-particles) having a particle diameter of 8 mm or more. Here, the compressive force of the briquette machine is preferably 0.5 tonf / cm (490 kN / m) or more as the axial pressure (load per axial length of the roll). The reason is that by doing so, sufficient hot strength can be obtained. Since an excessive load causes an increase in size of the device, a more preferable axial pressure is in the range of 0.7 to 1.8 tonf / cm (690 to 1760 kN / m).

Next, the carbonaceous material interior molded particles (pseudo-particles) obtained as described above are obtained by stirring the normal raw material 6 for sinter production with a drum mixer 7 and granulating the normal sinter production. Both particles are mixed with the granulated particles (pseudo-particles) to be mixed and carried into the surge hopper of the sintering machine 13, and charged from the surge hopper onto a pallet that circulates in the sintering machine. Since the carbonaceous material interior molded particles (pseudo-particles) have a larger particle size than ordinary granulated particles for sinter production (pseudo-particles), segregation occurs at the time of charging and the temperature at the time of sintering is higher. Since a large amount of particles are deposited on the middle layer and the lower layer side, which tend to be higher than the side, the sintering reaction is characterized by being sufficiently easy to proceed.

As described above, since the carbonaceous material interior sinter of the present invention can be produced by using a general DL sinter machine, it can be mass-produced at low cost. In addition, iron ore powder and coke breeze, which are the raw materials for the outer layer, can be obtained in large quantities at low cost without worrying about the particle size, so there are no restrictions on production. In addition, it is possible to reduce capital investment such as sieving machines and crushers.

Further, a sinter production facility suitable for producing the carbonaceous interior sinter of the present invention will be described.
In order to carry out the present invention, as shown in FIG. 2A, at least one hopper 8 for holding iron ore powder, a hopper 9 for holding a CaO-containing raw material, and a hopper 10 for holding a carbonaceous material are provided. A compression molding machine 11 that mixes, compresses, and molds at least iron ore powder, a raw material containing CaO, and a raw material containing a carbonaceous material to obtain carbonaceous material internal molding particles for producing sintered ore, and ordinary sintering. A surge in which a drum mixer 7 that granulates a raw material 6 for ore and uses it as a raw material particle for producing a sintered ore, and the carbonaceous material interior molding particles and the raw material particle for producing a sintered ore are mixed and held as a raw material for sintering. It is necessary to use a manufacturing facility having a hopper (not shown) and equipped with a Dwightroid type sintering machine 13 for sintering the above-mentioned sintered raw material charged from the surge hopper into a sintered ore. be. In the present invention, the sintered raw materials are prepared by at least two rows of devices, and they are connected by a raw material transfer line (not shown). The transport line in the present invention is not particularly limited as long as it can transport powder at a constant speed, but a belt conveyor or the like can be preferably used.

First, in the manufacturing equipment of the present invention, a hopper 8 in which iron ore powder is held, a hopper 9 in which a CaO-containing raw material is held, and a charcoal material are held for adjusting the carbonaceous interior molded particles for sinter manufacturing. At least one hopper 10 is provided, and a compression molding machine is provided. As the compression molding machine, a double roll type, a flat plate type briquette machine, a cylinder press type, or the like can be used. If necessary, a hopper (not shown) for holding an auxiliary material such as pregelatinized starch can also be provided. The compression molding machine of the present invention may be capable of obtaining molded particles having a predetermined size with a predetermined compressive force (load).

Further, the manufacturing equipment of the present invention is provided with a drum mixer 7 as a granulating device for adjusting raw material particles for normal sinter manufacturing. A known drum mixer can be used as the drum mixer of the present invention. The raw material 6 for sinter for granulation may be cut out from the raw material hopper used for adjusting the molded particles for the interior of the carbonaceous material, or cut out from the raw material hopper prepared separately and transported, if necessary. You may. As the raw material 6 used for the ordinary raw material particles for producing sinter, those generally used as the sinter raw material of the sinter can be widely used.

Further, the manufacturing equipment of the present invention is provided with a dwitroid type sintering machine having a surge hopper that mixes and holds the carbonaceous material interior molded particles and the raw material particles for producing sinter as a sinter raw material. The dwitroid type sintering machine is preferably a downward suction type dwightroid type sintering machine.

As an example of the invention, according to the flow of FIG. 2A, 93 mass% of iron ore powder (≦ 1 mm = 100%, -1 + 0.25 mm = 15%), 5 mass% of quicklime as a CaO source, and powder coke (arithmetic mean particle size 1. 5 mm,> 2.8 mm = 20%) is added to 2 mass% of the raw material, 4 mass% of pregelatinized starch is added as a binder, and a 1.2 cc (sphere equivalent diameter of about 13 mm) briquette is molded using a briquette machine. did. At that time, the load was set to 0.8 tonf / cm (780 kN / m) as the axial pressure, and the raw material water content was adjusted to 8 mass% as the internal number. The iron ore collected in the yard in a humidity-controlled state was sized and the water content was adjusted appropriately before use. The water content of quicklime and powdered coke was 0 mass%. As shown in FIG. 1A, coke powder was dispersed inside the briquette, and it was confirmed that sufficient coke was dispersed in the core of the briquette (inside the sintered interface). Here, the melting point of the mixed phase of iron ore and CaO was 1500 ° C.

This molded briquette was placed in an electric furnace kept warm at 1200 ° C., held for 2 minutes, and then taken out of the furnace. When the crushing strength of the heated briquette was measured with a uniaxial compression tester, it was about 20 to 30 kgf (196 to 294 N). The surface of the outer layer was a fragile structure, and peeling powder was generated, but the inside was a healthy structure. From the observation of the cross section, the sphere-equivalent diameter of the nucleus in which the carbonaceous material remained was about 4 mm, and the outer layer was about 2.5 mm in a thin place.

As a comparative example, according to the conventional method described in Patent Document 1, 93 mass% of iron ore (≦ 1 mm = 100%, -1 + 0.25 mm = 15%) and 5 mass of quicklime as a CaO source according to the flow of FIG. 2B. %, Powdered coke (arithmetic average particle size 1.5 mm,> 2.8 mm = 20%) was supplied to a disk pelletizer having a diameter of 1.2 m with a raw material of 2 mass%, and granulation was performed while adding water. Here, the iron ore collected in the yard in a humidity-controlled state was sized and the water content was appropriately adjusted before use. The water content of quicklime and powdered coke was 0 mass%.

Of the obtained granulated particles, the ratio of satisfying the target size of 10 mm was as low as about 10% to 50%, and the granulated particles did not contain small carbonaceous material interior granulated particles or carbonaceous material core. Many things were also generated. The carbonaceous material interior granulated particles having a temperature of about 10 mm were placed in an electric furnace kept at a temperature of 1300 ° C., held for 1.5 minutes, and then taken out from the furnace. When the crushing strength of the heated carbonaceous interior granulated particles was measured with a uniaxial compression tester, the strength was about 5 to 10 kgf (4.9 to 9.8 N).

The carbonaceous material interior molded particles of the invention example produced in Example 1 and ordinary granulated particles were charged into a sintering experiment pot having an inner diameter of 300 mmφ and a height of 400 mm in the raw material charging portion. In the lower layer side 1/3 (133 mm) of the raw material charging portion, the carbonaceous material interior granulated particles and the normal granulated particles are set to a mass ratio of 1: 1 and the carbonaceous material interior granulated particles are contained in the normal granulated particles. After charging normal granulated particles into the upper 2/3 (267 mm) of the mixture, the upper surface of the charged layer is ignited and the bottom of the test pot is charged. The blower disposed on the side sucked the air above the test pot and introduced it into the charging layer to burn the carbonaceous material in the sintered raw material. Here, the reason why the carbonaceous material interior granulated particles are embedded in the normal granulated particles in the lower layer side 1/3 is only the combustion heat of the surrounding normal granulated particles. By advancing the sintering reaction between the granulated particles and the outer layer of the inner granulated particles, it is possible to obtain the inner sintered ore without burning the carbonaceous material of the central core. This is because the lower layer side 1/3, in which the temperature tends to rise at the time of binding, is advantageous.
After the sinter experiment, the carbonaceous interior sinter obtained from the lower layer side 1/3 (133 mm) of the raw material charging part and the normal firing obtained from the upper layer side 2/3 (267 mm) of the raw material charging part. For calcination, the reducibility index (reduction rate) RI was measured by the method specified in JIS M8713: 2009, and the reduced pulverization index RDI was measured by the method specified in JIS M8720: 2009.

The RDI of the upper layer of the raw material was about 35, and the RDI of the lower layer was 40. On the other hand, the reducibility (RI) was 68 in the upper layer and 72 in the lower layer. It is considered that the reason why the RDI of the lower layer was higher than that of the upper layer was that the briquette became porous due to the disappearance of a part of the carbonaceous material in the briquette, and the strength after reduction decreased. On the other hand, since it is porous, it has become possible to produce a sinter having high reducibility.

The technique of the present invention is not limited to the above-described embodiment, for example, a sintering technique for supplying gaseous fuel in addition to the carbonaceous material added to the sintering raw material as a sintering heat source. Further, it can be applied to a sintering technique for enriching and supplying oxygen.

1 Charcoal material interior molded particles 2 Charcoal material (coke grains)
3 Mixed phase of iron ore powder and CaO-containing material 4 Sintered interface 5 Sintered interior granulated particles 6 Normal raw material for sintered ore 7 Drum mixer 8 Hopper for iron ore powder 9 Hopper for CaO-containing material 10 Coke material (coke) Hopper for powder) 11 compression molding machine (bricket machine)
12 Disc pelletizer 13 Sintering machine

Claims (8)

Sintered ore production carbonaceous material interior molding particles containing iron ore powder, CaO-containing raw material and carbonaceous material, and compression-molded by adjusting the water content to 4 to 10 mass%, are mixed with the sinter ore production raw material particles. When the sintering raw material is charged onto the pallet of the sintering machine to form the charging layer,
The charcoal is characterized in that a large amount of the carbon material interior molded particles are charged to the lower layer side of the charging layer, and the sinter is produced by the combustion heat of the carbon material contained in the raw material particles for producing the sinter. Material Interior Sintered ore manufacturing method. The method for producing a carbonaceous interior sintered ore according to claim 1, wherein the raw material particles for producing the sinter are granulated by a drum mixer and have a particle size smaller than that of the carbonaceous interior molded particles. .. The method for producing a carbonaceous interior sintered ore according to claim 1 or 2, wherein the iron ore powder is a powdered iron ore having a particle size of 1 mm or less. The charcoal interior sintered ore according to any one of claims 1 to 3, wherein the range from the outer surface of the carbon interior molded particles to 2 mm has a melting point of 1200 ° C. or higher and 1500 ° C. or lower. Production method. The method for producing a charcoal interior sintered ore according to any one of claims 1 to 4, wherein the charcoal material is coke particles having a particle size of 8 mm or less. The method for producing a charcoal interior sintered ore according to any one of claims 1 to 5, wherein the charcoal interior molded particles have a particle size of 8 mm or more. One of claims 1 to 6, wherein the charcoal material interior molded particles are a molded body obtained by molding iron ore powder, a CaO-containing raw material as a melting point adjuster, and the charcoal material using a compression molding machine. The method for producing a charcoal interior sintered ore according to item 1. Equipment used in the method for producing a charcoal interior sintered ore according to any one of claims 1 to 7.
At least one hopper for holding iron ore powder, one hopper for holding CaO-containing raw materials, and one hopper for holding charcoal material are provided.
A compression molding machine that mixes at least iron ore powder, raw materials containing CaO, and raw materials containing carbonaceous material, adjusts the water content to 4 to 10 mass%, compresses it, and molds it into carbonaceous material interior molding particles for sinter production. When,
A drum mixer that granulates ordinary raw materials for sinter and uses them as raw material particles for sinter production,
It has a surge hopper in which the carbonaceous material interior molded particles and the raw material particles for producing sinter are mixed and held as a sinter raw material, and the sintered raw material charged from the surge hopper is sintered and baked. A facility for manufacturing carbonaceous interior sinter, which is characterized by being equipped with a dwitroid type sinter for sinter.

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