KR20160074351A - Coal briquettes and method for manufacturing the same - Google Patents

Abstract

Provided is coal briquette which is charged into and rapidly heated in a dome part of a melting and gasification furnace into which reduced iron is charged, in a molten iron production device comprising the melting and gasification furnace and a reduction furnace which is connected to the melting and gasification furnace and to which the reduced iron is provided. Also provided is a production method thereof. The method for producing the coal briquette includes the following steps: providing pulverized coal; producing a mixture by mixing the pulverized coal and a binder; producing coal briquette by molding the mixture; infiltrating a polymer solution into a surface of the coal briquette; and drying the coal briquette into which the polymer solution is infiltrated.

Description

TECHNICAL FIELD [0001] The present invention relates to a blanket,

TECHNICAL FIELD The present invention relates to a briquette and a method of manufacturing the same. More particularly, the present invention relates to a briquette having an external crevice removed and a method of making the same.

In the melt reduction steelmaking method, a melting furnace for melting iron ores and a reduced iron ore is used. When molten iron ore is melted in a melter-gasifier, molten coal is charged into the melter-gasifier as a heat source for melting iron ore. Here, the reduced iron is melted in a melter-gasifier, converted to molten iron and slag, and then discharged to the outside. The briquetted coal charged into the melter-gasifier furnishes a coal-filled bed. Oxygen is blown through the tuyere installed in the melter-gasifier, and then the coal-packed bed is combusted to generate combustion gas. The combustion gas is converted into a hot reducing gas while rising through the coal packed bed. The high-temperature reducing gas is discharged to the outside of the melter-gasifier and supplied to the reducing furnace as a reducing gas.

The briquettes used in the melting and reducing steelmaking process are fed to a melter-gasifier furnace to provide the amount of heat required for melting the reduced iron. The blast furnace ensures air permeability and liquid permeability in the melter-gasifier so that gas and liquid can pass smoothly. To achieve this, the blast furnace must be maintained at a large particle size within the melting-gasification furnace. In this case, the reduction reaction and the heat transfer efficiency for the reduced iron can be increased by the briquette.

Therefore, the manufactured briquettes must be resistant to mechanical shock during transportation. When the blast furnace is charged into the dome by melt gasification at a temperature of 1000 캜, the hot strength must be excellent to ensure the air permeability and permeability of the melt gasifier.

In order to obtain excellent strength, water-soluble binder such as molasses, water-soluble acrylic emulsion, polyvinylalcohol (PVA) or water-soluble cellulose is added as a binder to increase the strength in the process of manufacturing the briquette. However, when a large amount of binder is used for ensuring sufficient strength, the cost of manufacturing the molded bodys is increased, causing adhesion in the manufacturing process, resulting in lowering of the operation rate of the equipment and deterioration of the quality.

And to provide a briquette having improved strength by removing external defects that cause cracks. Further, it is intended to provide a method for producing the above-described molded charcoal.

The method for producing molded coal according to one embodiment of the present invention is charged into a dome portion of a melter-gasifier in a molten steel making apparatus including a melter-gasifier furnished with reduced iron and a reducing furnace connected to the melter- The present invention relates to a method for manufacturing rapidly-heated shaped coal, comprising the steps of: providing pulverized coal (S10); producing a mixture by mixing pulverized coal and a binder (S20) A step (S40) of impregnating the polymer solution on the surface, and a step (S50) of drying the impregnated molded charcoal solution. The mixture may contain 5 wt% to 15 wt% binder and the remaining pulverized coal, and the amount of the polymer solution penetrating the surface of the pulverized coal may be 1 to 10 parts by weight based on 100 parts of the pulverized coal.

In the step of impregnating the polymer solution onto the surface of the briquettes, the polymer solution is selected from the group consisting of cellulose ether, polyvinyl alcohol, acrylic emulsion, polyacrylamide, polyethylene, polypropylene, polystyrene, acrylonitrile butadiene styrene and polyethylene terephthalate And may include one or more polymeric materials.

In the step of impregnating the polymer solution on the surface of the briquette, the polymer material contained in the polymer solution may have a viscosity of 500 cps to 50000 cps.

In the step of impregnating the polymer solution on the surface of the briquette, the concentration of the polymer substance in the polymer solution may be 0.1 wt% to 5 wt%.

In the step of drying the bombed charcoal impregnated with the polymer solution, the bombarded charcoal can be dried at 10 캜 to 150 캜.

The molded coal in which the polymer solution is impregnated can be dried at 60 ° C to 100 ° C.

The molten gasification furnace according to an embodiment of the present invention is charged into a dome portion of a melter-gasifier in a molten steel making apparatus including a melter-gasifier furnished with reduced iron and a reducing furnace connected to the melter- As the briquetted coal, it is a blast furnace containing 5 wt% to 15 wt% of binder and the remaining pulverized coal, and the surface of the briquetted coal is coated with a polymer material.

The polymer material may be at least one polymer material selected from the group consisting of cellulose ether, polyvinyl alcohol, acrylic emulsion, polyacrylamide, polyethylene, polypropylene, polystyrene, acrylonitrile butadiene styrene and polyethylene terephthalate.

The polymeric material can be coated with an average thickness of 1 탆 to 1000 탆.

It is possible to remove external defects that cause cracks in the molded body. As a result, it is possible to produce briquette having excellent strength.

Fig. 1 is a schematic flow chart of a method of manufacturing a briquette according to an embodiment of the present invention.
Fig. 2 is an enlarged cross-sectional view of the surface of the molded carbon produced in Fig.
Fig. 3 is a schematic view of a molten iron manufacturing apparatus using the briquettes manufactured in Fig. 1. Fig.
Fig. 4 is a schematic view of another molten iron manufacturing apparatus using the briquette produced in Fig. 1. Fig.
5 is a scanning electron microscope (SEM) image of the surface of the molded carbon produced in Comparative Example 1. Fig.

The terms first, second and third, etc. are used to describe various portions, components, regions, layers and / or sections, but are not limited thereto. These terms are only used to distinguish any moiety, element, region, layer or section from another moiety, moiety, region, layer or section. Thus, a first portion, component, region, layer or section described below may be referred to as a second portion, component, region, layer or section without departing from the scope of the present invention.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms as used herein include plural forms as long as the phrases do not expressly express the opposite meaning thereto. Means that a particular feature, region, integer, step, operation, element and / or component is specified and that the presence or absence of other features, regions, integers, steps, operations, elements, and / It does not exclude addition.

Unless otherwise defined, all terms including technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Commonly used predefined terms are further interpreted as having a meaning consistent with the relevant technical literature and the present disclosure, and are not to be construed as ideal or very formal meanings unless defined otherwise.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 schematically shows a flow chart of a method of manufacturing a briquette according to an embodiment of the present invention. The flow chart of the method of manufacturing the briquette of Fig. 1 is merely for illustrating the present invention, and the present invention is not limited thereto. Therefore, the method of manufacturing the briquette can be variously modified.

First, in step S10, pulverized coal is provided. Here, the pulverized coal is pulverized coal. In general, the coal generally contains about 60% of carbon, about 70% of atan and lignite, about 70% to 80% of bituminous coal, about 80% to 90% Bituminous coal, and 90% or more anthracite. The type of coal used here is not particularly limited, and a single type of coal or various kinds of coal can be mixed and used. In order to reduce variation in quality, it is preferable that the particle size of the pulverized coal is constant, and as a specific criterion, pulverized coal having a particle size distribution of not more than 3 mm in size of 80 wt% or more and a particle size of 5 mm or less in 90 wt% or more can be used.

Next, in step S20, the binder is mixed with the pulverized coal to prepare a mixture. As the binder, molasses, starch, raw sugar, polymer resin, cellulose, tar, bitumen, water glass or oil may be used. The binder may be mixed at 3 wt% to 15 wt% of the mixture. If the amount of the binder is too small, the strength of the briquette may be deteriorated. In addition, when the amount of the binder is too large, problems such as adherence occur when the pulverized coal and the binder are mixed. Therefore, the amount of the binder is adjusted to the above-mentioned range. Since the external defect is removed by the polymer material, even if the amount of the binder is reduced, a comparable strength can be obtained. More preferably, the amount of the binder may be from 5 wt% to 8 wt%.

On the other hand, although not shown in FIG. 1, 1 wt% to 5 wt% of a curing agent may be added to the mixture. As the hardening agent, calcium oxide, calcium hydroxide, calcium carbonate, cement, bentonite, clay or limestone can be used. When the amount of the curing agent is too small, the bonding strength between the binder and the curing agent does not sufficiently take place and the strength of the molded cement can not be sufficiently secured. In addition, when the amount of the curing agent is too large, the amount of ash in the briquette is increased, and the fuel can not sufficiently serve as a fuel in the melting-gasification furnace. Accordingly, the amount of the curing agent is adjusted to the above-mentioned range.

In step S30, the mixture is molded to produce a blast furnace. Although not shown in FIG. 1, the mixture can be charged between twin rolls rotating in mutually opposite directions to produce molded pockets or strips. As a result, it is possible to produce briquette having excellent hot strength and cold strength.

In step S40, the polymer solution is impregnated on the surface of the briquette. Examples of the polymer material included in the polymer solution include water-soluble polymers such as cellulose ether, polyvinyl alcohol (PVA), acrylic emulsion, and polyacrylamide; Polymeric resins such as polyethylene (PE), polypropylene (PP), polystyrene (PS), acrylonitrile butadiene styrene (ABS), and polyethylene terephthalate . Among them, hydroxypropylmethyl cellulose (HPMC) or hydroxyethyl cellulose (HEC) can be used as a material using cellulose ether.

The polymer material preferably has a viscosity of 500 cps to 50000 cps. The concentration of the polymer substance in the polymer solution is preferably 0.1 wt% to 5 wt%. More specifically, it is more preferable that it is 0.2 wt% to 2 wt%. Further, it is more preferable that it is 0.5 wt% to 1 wt%. The solvent contained in the polymer solution is not particularly limited as long as it is a solvent capable of uniformly dissolving the polymer substance.

The amount of the polymer solution is preferably 0.5 to 10 parts by weight based on 100 parts by weight of the molded body. If the amount of the polymer solution to be infiltrated is less than 0.5 part by weight, there is a problem that the penetration effect of the polymer solution is difficult to manifest. If the amount of the polymer solution to be infiltrated exceeds 10 parts by weight, More preferably, the amount of the polymer solution may be 1 part by weight to 5 parts by weight based on 100 parts by weight of the molded product.

On the other hand, unlike the above, when the molded coal is produced by spraying the steel byproducts on the surface of the briquettes, waste oil or waste grease which is a by-product of steel has a function of preventing water from penetrating into the briquettes, but it can not improve drop strength and compressive strength . This is because the oil film applied by waste oil or waste grease does not have its own rigidity. In addition, a sufficient amount of waste oil or waste grease for mass production is difficult to supply and receive.

Examples of the method of impregnating the polymer solution on the surface of the briquette include a method of spraying the polymer solution onto the surface using a high-pressure injection nozzle, or a method of directly transferring the solution through a brush or the like.

Finally, in step S50, the polymerized solution is impregnated with the dried briquettes. In this case, the polymer material contained in the briquettes forms a polymer bridge. The drying temperature may be from 10 캜 to 150 캜. If the drying temperature is too low, the briquette may not dry well. Further, when the drying temperature is too high, for example, cracks may be generated in the briquettes when heated air of 150 ° C or higher. Therefore, it is preferable to adjust the drying temperature to the above-mentioned range. On the other hand, in the case of cold air having a low drying temperature, it is necessary to reduce the humidity to a minimum to increase drying efficiency. In order to improve the self-strength of the polymer bridge and the adhesion between the polymer bridge and the main body of the molded body, it is more preferable to adjust the drying temperature to 60 to 100 캜. Further, it may be more preferable to adjust the drying temperature to 70 ° C to 90 ° C. The molded coal can be dried for 30 minutes to 5 days, and it is preferable to sufficiently dry for 1 to 5 days at a temperature of 10 to 50 캜.

The average thickness of the polymer coated on the surface of the burnt carbon through this method may be 1 탆 to 1000 탆. If the average thickness is too small, the strength of the briquette may not be sufficiently improved. If the average thickness is too large, there may be a problem of adhesion in the process, so it is preferable to adjust the thickness to the above-mentioned range.

Fig. 2 schematically shows a cross-sectional structure of the surface of the molded body 100 manufactured in Fig. The internal cross-sectional structure of the molded body 100 of FIG. 2 is merely for illustrating the present invention, and the present invention is not limited thereto. Therefore, the internal cross-sectional structure of the briquette can be modified to other forms.

2, the molded body 100 includes a body portion 10, a polymer bridge 20, an external defect 30, a crack tip 40, and a crack 50. Here, the external defect 30 is formed on the surface of the molded body 100, and the polymer bridge 20 penetrates the surface of the molded body 100 to cover the external defect 30. When the polymer bridge 20 is not present, the stress is concentrated on the crack tip 40 formed by the external defect 30, so that the crack 50 is expanded inside the body portion 10. However, in one embodiment of the present invention, the polymer bridge 20 covers the external defects 30 to disperse external stress, so that the strength of the molded carbon can be improved.

Fig. 3 schematically shows a molten iron manufacturing apparatus 200 using the shaped coal produced in Fig. The structure of the molten iron manufacturing apparatus 200 of FIG. 3 is merely for illustrating the present invention, and the present invention is not limited thereto. Therefore, the molten iron manufacturing apparatus 200 of FIG. 3 can be modified into various forms.

The molten iron manufacturing apparatus 200 of FIG. 3 includes a melter-gasifier 110 and a reduction furnace 120. In addition, other devices may be included if desired. In the reduction furnace 120, iron ore is charged and reduced. The iron ore charged in the reducing furnace 120 is pre-dried and then made into reduced iron through the reducing furnace 120. The reduction furnace 120 is a packed-bed reduction reactor, and a reducing gas is supplied from the melter-gasifier furnace 110 to form a packed bed therein.

Since the briquettes produced by the manufacturing method of FIG. 1 are charged into the melter-gasifier 110, a coal-filled layer is formed inside the melter-gasifier 110. A dome portion 101 is formed on the upper portion of the melter-gasifier 110. That is, a larger space is formed compared with other portions of the melter-gasifier 110, and a high-temperature reducing gas exists therein. Therefore, the briquettes charged into the dome portion 101 by the high-temperature reducing gas can be easily differentiated. However, since the blast furnace produced by the method of FIG. 1 has a high hot strength, it does not differentiate in the dome portion of the melter-gasifier 110 and falls down to the lower portion of the melter-gasifier 110. The gas generated by the pyrolysis reaction of the briquettes moves to the lower portion of the melter-gasifier (110) and exothermically reacts with oxygen supplied through the tuyeres (130). As a result, the briquettes can be used as a heat source for keeping the melter-gasifier 110 at a high temperature. Meanwhile, since the furnace provides air permeability, a large amount of gas generated in the lower portion of the melter-gasifier furnace 110 and the reduced iron supplied from the furnace 120 can more easily and uniformly pass through the coal packed bed in the melter- .

The lump gasification furnace 110 may be charged with the lumpy carbonaceous material or the coke as needed in addition to the above-mentioned formed coal. A tuyere (130) is installed on the outer wall of the melter-gasifier (110) to blow oxygen. Oxygen is blown into the coal packed bed to form a combustion zone. The briquettes can be burned in the combustion zone to generate reducing gas.

Fig. 4 schematically shows an apparatus 300 for manufacturing molten iron using the briquettes produced in Fig. The structure of the molten iron manufacturing apparatus 300 of FIG. 4 is merely for illustrating the present invention, and the present invention is not limited thereto. Therefore, the molten iron manufacturing apparatus 300 of FIG. 4 can be modified into various forms. Since the structure of the molten iron manufacturing apparatus 300 of FIG. 4 is similar to that of the molten iron manufacturing apparatus 200 of FIG. 3, the same reference numerals are used for the same parts, and a detailed description thereof will be omitted.

4, the molten iron manufacturing apparatus 300 includes a melter-gasifier 110, a reducing furnace 122, a reduced iron compactor 140, and a compacted iron storage tank 150. As shown in FIG. Here, the compressed reduced iron storage tank 150 may be omitted.

The produced briquettes are charged into the melter-gasifier (110). Here, the blast furnace generates a reducing gas in the melter-gasifier 110, and the generated reducing gas is supplied to the fluidized-bed reduction reactor. The minute iron ores are supplied to a plurality of reduction furnaces 122 having a fluidized bed and are made of reduced iron while flowing by the reducing gas supplied from the melter-gasifier 110 to the reduction furnaces 122. The reduced iron is compressed by the reduced iron compactor 140 and then stored in the compacted iron storage tank 150. The compressed reduced iron is supplied to the melter-gasifier (110) from the compacted iron storage tank (150) and melted in the melter-gasifier (110). A large amount of gas generated in the lower portion of the melter-gasifier 110 and the compressed reduced iron make the coal filler layer in the melter-gasifier 110 more easily and uniformly distributed in the melter-gasifier furnace 110, So that a good quality molten iron can be produced.

Hereinafter, the present invention will be described in more detail with reference to experimental examples. However, these experimental examples are only for illustrating the present invention, and the present invention is not limited thereto.

Experimental Example 1

Coal A (90 wt%) having a particle size of 4 mm or less was prepared as pulverized coal with an average property. Coke dust (10 wt%) was added to the pulverized coal as a carbon source additive. The properties of the coal A and the coke dust used are shown in Table 1 below.

Industrial analysis, dry base wt% Ashes (Ash) Volatile matter (VM) Fixed Carbon Coal A 9.1 25.1 65.8 Coke dust 14.6 1.8 83.6

8 parts by weight of molasses was added as a binder to 100 parts by weight of the pulverized coal, uniformly mixed, and then compressed by a pair of forming rolls to prepare pillow-shaped molded charcoal having a size of 64.5 mm X 25.4 mm X 19.1 mm. A polymer solution (HEC aqueous solution, concentration 2 wt%) corresponding to 2 parts by weight with respect to 100 parts by weight of the briquette was sprayed onto the surface of the molded blanks, and uniformly infiltrated. Thereafter, it was dried at room temperature for 1 hour and 30 minutes, and the compressive strength and drop strength were measured by the following method.

Experimental Example 2

A 0.5 wt% HPMC aqueous solution was used as the polymer solution. The remaining experimental procedure was the same as Experimental Example 1.

Experimental Example 3

After impregnating the polymer solution, it was dried at 80 DEG C for 1 hour. The remaining experimental procedure was the same as Experimental Example 1.

Experimental Example 4

A 0.5 wt% HPMC aqueous solution was used as the polymer solution, and the polymer solution was impregnated and then dried at 80 DEG C for 1 hour. The remaining experimental procedure was the same as Experimental Example 1.

Experimental Example 5

After impregnating the polymer solution, it was dried at room temperature for 5 days. The remaining experimental procedure was the same as Experimental Example 1.

Experimental Example 6

A 0.5 wt% HPMC aqueous solution was used as the polymer solution, and the polymer solution was impregnated and then dried at room temperature for 5 days. The remaining experimental procedure was the same as Experimental Example 1.

Comparative Example 1

The polymer solution was not impregnated into the molded briquettes. The remaining experimental procedure was the same as Experimental Example 1.

Comparative Example 2

Water was sprayed instead of the polymer solution to the molded briquettes to uniformly infiltrate. The remaining experimental procedure was the same as Experimental Example 1.

Comparative Example 3

The polymer solution was not impregnated into the molded briquettes. The remaining experimental procedure was the same as Experimental Example 3.

Comparative Example 4

Water was sprayed instead of the polymer solution to the molded briquettes to uniformly infiltrate. The remaining experimental procedure was the same as Experimental Example 3.

Comparative Example 5

The polymer solution was not impregnated into the molded briquettes. The remaining experimental procedure was the same as Experimental Example 5.

Comparative Example 6

Water was sprayed instead of the polymer solution to the molded briquettes to uniformly infiltrate. The remaining experimental procedure was the same as Experimental Example 5.

Compression strength evaluation experiment

Thirty pieces of the manufactured briquettes were fixed at the bottom and pressed at a constant speed at the top to measure the maximum load until breaking.

Drop strength evaluation experiment

The weight ratio of the briquettes, which have been manufactured at a height of 50 mm or more from the ground and maintained at a particle size of 20 mm or more, is expressed as a percentage of the weight of the total briquettes.

Polymer solution Drying conditions Compressive strength (kgf) Drop strength (%) Experimental Example 1 HEC 2 wt% aqueous solution Room temperature
1.5 hours 24 56 Experimental Example 2 HPMC 0.5wt% aqueous solution Room temperature
1.5 hours 23 58 Experimental Example 3 HEC 2 wt% aqueous solution 80 ℃
1 hours 71 64 Experimental Example 4 HPMC 0.5wt% aqueous solution 80 ℃
1 hours 78 63 Experimental Example 5 HEC 2 wt% aqueous solution Room temperature
5 days 102 68 Experimental Example 6 HPMC 0.5wt% aqueous solution Room temperature
5 days 105 70 Comparative Example 1 Do not infiltrate Room temperature
1.5 hours 29 52 Comparative Example 2 water Room temperature
1.5 hours 22 51 Comparative Example 3 Do not infiltrate 80 ℃
1 hours 69 55 Comparative Example 4 water 80 ℃
1 hours 67 56 Comparative Example 5 Do not infiltrate Room temperature
5 days 90 55 Comparative Example 6 water Room temperature
5 days 87 56

As shown in Table 2, it was confirmed that the molded cells of Experimental Example 1 and Experimental Example 2 were superior in drop strength as compared with those of Comparative Examples 1 and 2. Compared with the briquettes of Comparative Example 3 and Comparative Example 4, the molded briquettes of Experimental Examples 3 and 4 are superior in both compression strength and drop strength. This is because the molded body was dried at a relatively high temperature to improve the strength of the polymer substance itself and to improve the adhesion of the polymer substance to the molded body.

It was found that the molded carbons of Experimental Example 5 and Experimental Example 6 had both excellent compressive strength and drop strength as compared with the molded carbons of Comparative Example 5 and Comparative Example 6. [ It was considered that the strength of the polymer material itself was improved by drying at room temperature for a relatively long time, and the adhesion between the polymer material and the main body of the molding was improved.

5 is a scanning electron microscope (SEM) image of the surface of the molded carbon produced in Comparative Example 1. Fig. The scanning electron micrograph of FIG. 5 was magnified 3,000 times.

As shown in Fig. 5, when the briquettes were observed with an electron microscope, it was found that external defects that caused fine cracks were formed. External defects on the surface of the burnt carbon cause stress concentration and become the starting point of propagation of the cracks, thus lowering the hot strength of the briquette. Therefore, when the polymer solution is infiltrated into the surface of the briquette, such external defects can be removed to improve the hot strength and cold strength of the briquette.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims. As will be understood by those skilled in the art. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive.

100. Molded Carbon
10. Body part
20. Polymer bridge
30. External defect
40. Crack Tips
50. Crack
110. Melting-gasification furnace
120, 122. Reduction furnace
130. Tungus
140. Reduction iron compression unit
150. Compressed reduced iron storage tank
200, 300. Molten iron manufacturing equipment
101. Dome

Claims (9)

A melter-gasifier furnished with reduced iron, and
A reducing furnace connected to the melter-gasifier and providing the reduced iron;
Wherein the molten iron is charged into a dome of the melting and gasifying furnace and rapidly heated,
Providing pulverized coal,
Mixing the pulverized coal and the binder to prepare a mixture,
Molding the mixture to produce a molded coal,
Permeating the polymer solution onto the surface of the briquette, and
Drying the impregnated blanket with the polymer solution
Lt; / RTI >
Wherein the mixture comprises 5 wt% to 15 wt% of a binder and the remaining pulverized coal, and the amount of the polymer solution penetrating the surface of the pulverized coal is 1 to 10 parts by weight based on 100 parts of the pulverized coal. The method according to claim 1,
In the step of impregnating the polymer solution onto the surface of the molded body, the polymer solution is a polymer solution comprising a polymer selected from the group consisting of cellulose ether, polyvinyl alcohol, acrylic emulsion, polyacrylamide, polyethylene, polypropylene, polystyrene, acrylonitrile butadiene styrene and polyethylene terephthalate ≪ / RTI > wherein the at least one polymeric material is selected from the group consisting of: The method according to claim 1,
Wherein the polymer material contained in the polymer solution has a viscosity of 500 cps to 50000 cps in the step of impregnating the polymer solution on the surface of the molded product. The method according to claim 1,
Wherein a concentration of the polymer material in the polymer solution is 0.1 wt% to 5 wt% in the step of impregnating the polymer solution on the surface of the molded product. The method according to claim 1,
Wherein the molding is dried at a temperature of from 10 캜 to 150 캜 at the step of drying the molded polymer impregnated with the polymer solution. 6. The method of claim 5,
Wherein the molded polymer in which the polymer solution is impregnated is dried at 60 ° C to 100 ° C. A melter-gasifier furnished with reduced iron, and
A reducing furnace connected to the melter-gasifier and providing the reduced iron;
Wherein the molten steel is charged into a dome of the melting and gasifying furnace and rapidly heated,
5 wt% to 15 wt% binder, and the remaining fine coal,
Wherein the surface of the briquette is coated with a polymer material. 8. The method of claim 7,
Wherein the polymeric material is at least one polymeric material selected from the group consisting of cellulose ether, polyvinyl alcohol, acrylic emulsion, polyacrylamide, polyethylene, polypropylene, polystyrene, acrylonitrile butadiene styrene and polyethylene terephthalate. 8. The method of claim 7,
Wherein the polymeric material is coated with an average thickness of 1 占 퐉 to 1000 占 퐉.

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