KR101634069B1 - Coal briquettes and method for manufacturing the same - Google Patents

Abstract

Provided is coal briquette which is charged into a dome part of a melting and gasification furnace and rapidly heated, in a molten iron production device comprising: the melting and gasification furnace into which reduced iron is charged; and a reduction furnace which is connected to the melting and gasification furnace and provides the reduced iron. 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; and producing the coal briquette by molding the mixture.

Description

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

And a method of manufacturing the same. More particularly, the present invention relates to a briquette having excellent strength and suppressed defective shape and a method of manufacturing 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 are produced by mixing the pulverized coal with the coal and the binder and molding them. That is, the binder first binds the pulverized coal with each other to form a lump. Then, the pulverized coal is squeezed by the molding process and made into a molded coal having appropriate strength.

And to provide a method for manufacturing molded-on-a-carbon which is capable of preventing the defective shape of the molded-formed carbon and preventing breakage of the fraction of the molded-in carbon and the molded-in carbon. Further, there is a need to provide a molded carbon produced by the above-described method for producing molded coal.

There is provided a molten steel producing apparatus including a melter-gasifier furnished with reduced iron and a reducing furnace connected to the melter-gasifier furnace, and a reducing furnace for providing reduced iron. The method includes the steps of providing pulverized coal (S10), mixing a pulverized coal and a binder to produce a mixture (S20), and molding the mixture to produce a molded coal (S30) . In the step of preparing the mixture, the binder includes molasses, caramel, and water.

In the step of preparing the mixture, the binder may comprise 10 wt% to 75 wt% molasses, 2 wt% to 20 wt% caramel, and the balance water. More specifically, the amount of molasses may be 50 wt% to 70 wt%, and the amount of caramel may be 5 wt% to 20 wt%.

In the step of preparing the mixture, the caramel can be prepared from the sugar by a caramelization reaction.

In the step of preparing the mixture, the amount of binder to the mixture may be from 3 wt% to 12 wt%.

In the step of preparing the mixture, the curing agent is further mixed into the mixture, and the amount of the curing agent may be 1 wt% to 5 wt% of the mixture.

And a reducing furnace connected to the melter-gasifier for supplying reduced iron to the dome of the melter-gasifying furnace to rapidly heat the melter-gasifier. Examples of the shaped coal include pulverized coal and a binder, and the binder includes molasses, caramel, and water.

The binder may comprise from 10 wt% to 75 wt% molasses, from 2 wt% to 20 wt% caramel, and balance water.

The amount of molasses may be from 50 wt% to 70 wt%.

It is possible to suppress the defective shape during the molding process. As a result, it is possible to prevent the fractions of the briquettes and the breakage of the briquettes.

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 a schematic view of a molten iron manufacturing apparatus using the shaped coal produced in FIG.
FIG. 3 is a schematic view of another molten iron manufacturing apparatus using the shaped coal produced in FIG. 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.

As shown in FIG. 1, the method for producing molded coal includes the steps of providing pulverized coal (S10), mixing the pulverized coal and binder to provide a mixture (S20), and molding the mixture to produce blasted coal (S30) . In addition, if necessary, the method of manufacturing the molded coal may further include other steps.

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 herein 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, pulverized coal having a uniform particle size can be used. As a specific criterion, pulverized coal having a particle size distribution of 90% by weight to 100% by weight of 3 mm or less can be used.

In addition, the moisture content of the pulverized coal can be adjusted to 3 wt% to 12 wt%. When the amount of water mixed in the pulverized coal is adjusted to the above-mentioned range, the moisture blocks the pores of the pulverized coal particles. As a result, since the binder can not penetrate into the pulverized particle and is present outside the pulverized particle, the pulverized coal particles can be bonded well to each other to efficiently improve the hot strength and the cold strength of the shaped coal.

Next, in step S20, a mixture is prepared by mixing pulverized coal and a binder. As the binder, a binder including molasses, caramel, and water can be used. It is possible to prevent the phenomenon that the shape of the briquettes is defective due to the blending of molasses and caramel as a binder, so that the shape of the briquettes is adhered to the surfaces of the twin rolls in the molding process. And the strength of the briquette can be maintained.

In order for the binder to function, adhesion and cohesion must be good. Adhesion is an ability to be effectively applied to the substance to which the binder is adhered, which is a necessary function when the pulverized coal is mixed with the binder. Adhesion is the ability to bind binders after they have been applied. This is a function required in the step of strongly binding the binders after they are applied to the material. Materials with low molecular weight exhibit effective adhesion and materials with high molecular weight exhibit effective adhesion. When the mixture of pulverized coal and the binder is molded, the pulverized coal and the binder are bundled at the time of molding by the twin rolls rotating in mutually opposite directions, so that the pulverized coal is not bonded to the surface of the twin rolls. That is, when the pulverized coal is attached to the surface of the twin rolls, the shape of the molded coal is broken. The defective shape of the briquette leads to an increase in the fraction of the briquette and breakage of the briquette, which in turn decreases the efficiency of the briquette production. In the case of producing molten carbonate using molasses as a binder, some of the burnt carbon adhered to the surfaces of the twin rolls in the molding step, resulting in defective shape.

When molasses is used as a binder, molasses is attached to the surface of the twin rolls for forming the mixture, resulting in frequent defects in the shape of the molten boll. On the other hand, the adhesion of caramel is comparable to that of molasses, but it is weaker than that of molasses in terms of adhesion. Therefore, when molasses and caramel are mixed and used as a binder, the mixture does not adhere well to the surfaces of the twin rolls, so that the defective shape of the briquettes can be suppressed and the strength of the briquette can be improved. In the case of caramel composed of only a substance having a high molecular weight as compared to molasses in which low molecular weight (disaccharide, monosaccharide) materials are mainly constituted, adhesion is effectively generated to enhance bonding ability between particles and adherence to the surface of the twin roll It does not happen.

The binder may comprise from 10 wt% to 75 wt% molasses, from 2 wt% to 20 wt% caramel, and balance water. If the caramel is contained in the binder in an insufficient amount, defective shape of the briquette may not be improved. Further, when the caramel is contained in too much of the binder, the strength of the briquette can be lowered. Therefore, the amount of caramel contained in the binder can be adjusted to the above-mentioned range.

In addition, when the binder contains too little water, the viscosity of the binder rises and it is difficult to transfer during the process. Further, when the binder contains too much water, the moisture content of the whole of the molded body becomes high, so that the strength of the molded body may be lowered. Therefore, it is preferable to control the water content in the above-mentioned composition range.

The composition ratio of the binder may be 20 wt% to 73 wt% molasses, 3 wt% to 20 wt% caramel, and the balance water, based on the total weight of the binder. More specifically, the binder may comprise 50 wt% to 70 wt% molasses, 5 wt% to 20 wt% caramel, and the balance water.

Caramel can be produced by a ring-opening reaction in which the ring of the monosaccharide is opened at 20 DEG C or higher. In addition, caramel decomposes the polysaccharide into monosaccharides at a temperature of 50 ° C or higher and undergoes a ring-opening reaction in which the ring of the monosaccharide is ring-opened, and undergoes a condensation reaction to form a polymer. Such a reaction to produce caramel from sugar is called caramelization. Ammonia can be added to further accelerate the caramelization reaction. The monosaccharide may be glucose, fructose, xylose, etc. The polysaccharide may be sucrose, lactose, or the like. When the caramel is analyzed in a 10 mm cell using an ultraviolet spectrometer, the band near 610 nm and the absorption rate is 0.15 to 2.0. Also, the viscosity of the caramel is within the range of 10000 cp to 50000 cp based on the concentration of 65 wt%.

For uniform mixing, molasses may be first added to the pulverized coal and then caramel may be added. That is, when molasses and caramel are mixed together, the reaction between molasses and caramel may occur before pulverized coal. In addition, it is preferable to first introduce molasses to the pulverized coal, because it is preferable to induce the adhesion phenomenon first, rather than the sticking phenomenon, in order to secure the strength of the briquette.

The amount of binder contained in the mixture may be from 3 wt% to 15 wt%. 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.

On the other hand, although not shown in FIG. 1, a curing agent may be further mixed in the mixture. The amount of the curing agent relative to the mixture may be from 1 wt% to 5 wt%. As the hardening agent, CaO, Ca (OH) ₂ , MgO, Mg (OH) ₂ , Na ₂ O, NaOH, K ₂ O, KOH and the like can be used. When the amount of the curing agent is too small, the binder and the curing agent are not sufficiently combined, and the strength of the molded cement can not be sufficiently increased. In addition, when the amount of the hardener is too large, the amount of ash in the briquettes increases, and heat required for melting the reduced iron in the melting-gasification furnace can not be sufficiently discharged. Accordingly, the amount of the curing agent is adjusted to the above-mentioned range. Particularly, CaO in the hardener can further increase the strength of the molded charcoal through the saccharate reaction with the molasses in the binder.

Finally, in step S30, the mixture is molded to produce a blast furnace. Although not shown in FIG. 1, the mixture may be charged between twin rolls rotating in mutually opposite directions to produce molded pockets or strips.

Fig. 2 schematically shows a molten iron manufacturing apparatus 100 using the shaped coal produced in Fig. The structure of the apparatus for manufacturing molten iron 100 of FIG. 2 is merely for illustrating the present invention, and the present invention is not limited thereto. Therefore, the molten iron manufacturing apparatus 100 of FIG. 2 can be modified into various forms.

The molten iron manufacturing apparatus 100 of FIG. 2 includes a melter-gasifier 10 and a reduction furnace 20. In addition, other devices may be included if desired. In the reduction furnace 20, iron ore is charged and reduced. The iron ore to be charged into the reduction furnace 20 is preliminarily dried and then made into reduced iron through the reduction furnace 20. The reduction furnace 20 is a packed-bed reduction reactor, and a reducing gas is supplied from the melter-gasifier furnace 10 to form a packed bed therein.

Since the briquettes produced by the production method of Fig. 1 are charged into the melter-gasifier 10, a coal-filled layer is formed inside the melter-gasifier 10. A dome portion 101 is formed on the upper portion of the melter-gasifier 10. That is, a larger space is formed compared with other portions of the melter-gasifier 10, and a high-temperature reducing gas is present therein. Therefore, the briquettes charged into the dome portion 101 by the high-temperature reducing gas can be easily differentiated. However, since the briquettes produced by the method of FIG. 1 have high strength and little fractions and breakage, they are not differentiated in the dome portion of the melter-gasifier 10 and descend to the lower portion of the melter-gasifier 10. The gas generated by the pyrolysis reaction of the blast furnace moves to the lower part of the melter-gasifier 10 and exothermically reacts with the oxygen supplied through the tuyere 30. As a result, the briquettes can be used as a heat source for keeping the melter-gasifier 10 at a high temperature. On the other hand, since the furnace provides air permeability, a large amount of gas generated in the lower portion of the melter-gasifier 10 and the reduced iron supplied from the reducing furnace 20 can more easily and uniformly pass through the coal packed bed in the melter- .

The lump gasification furnace 10 may be charged with lumpy carbonaceous material or coke as needed in addition to the above-mentioned shaped coal. A tuyere (30) is installed on the outer wall of the melter-gasifier (10) 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. 3 schematically shows an apparatus 200 for manufacturing molten iron 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 structure of the molten iron manufacturing apparatus 200 of FIG. 3 is similar to the structure of the molten iron manufacturing apparatus 100 of FIG. 2, and thus the same reference numerals are used for the same parts, and detailed description thereof is omitted.

3, the molten iron manufacturing apparatus 200 includes a melter-gasifier 10, a reduction reactor 22, a reduction iron compactor 40, and a compacted iron storage tank 50. Here, the compressed reduced iron storage tank 50 may be omitted.

The produced briquettes are charged into the melter-gasifier (10). Here, the briquetting gas generates a reducing gas in the melter-gasifier 10, 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 22 having a fluidized bed and are made of reduced iron while flowing by the reducing gas supplied from the melter-gasifier 10 to the reduction furnaces 22. [ The reduced iron is compressed by the reduced iron compactor 40 and then stored in the compacted iron storage tank 50. The compressed reduced iron is supplied to the melter-gasifier 10 from the compressed-reduced iron storage tank 50 and melted in the melter-gasifier 10. A large amount of gas generated in the lower portion of the melter-gasifier 10 and the compressed reduced iron make the coal filler layer in the melter-gasifier 10 more easily and uniformly distributed in the melter-gasifier 10, 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.

Caramel manufacturing experiment

A sugar mixture consisting of sucrose, glucose and fructose was dissolved in water at a concentration of 65 wt% to prepare 1 L of the aqueous sugar solution. 1 L of the aqueous sugar solution was maintained in an autoclave at a temperature of 150 캜 for 5 hours to prepare a caramel solution.

Experimental Example 1

Pulverized coal having an average property of 90 wt% or more with a particle size of 3 mm or less was prepared. The quicklime was added to the prepared pulverized coal in an amount of 3 wt% and mixed for 1 minute. Thereafter, molasses was added and mixed for 3 minutes. Thereafter, caramel was added and mixed for 3 minutes. 71 wt% molasses, 4 wt% of caramel, and 25 wt% of water were mixed with respect to the total binder weight, respectively. The amount of the binder was 8 wt% of the pulverized coal, and the remainder excluding the burnt lime and the binder was pulverized coal. The mixture was compressed with a pair of forming rolls to produce pellet-shaped shaped bins having a size of 64.5 mm X 25.4 mm X 19.1 mm.

Experimental Example 2

68 wt% molasses, 7 wt% of caramel, and 25 wt% of water were mixed with respect to the total binder weight, respectively. The remaining experimental procedure was the same as Experimental Example 1.

Experimental Example 3

64 wt% molasses, 11 wt% of caramel, and 25 wt% of water were mixed with respect to the total binder weight, respectively. The remaining experimental procedure was the same as Experimental Example 1.

Experimental Example 4

60 wt% molasses, 15 wt% of caramel, and 25 wt% of water were mixed with respect to the total binder weight, respectively. The remaining experimental procedure was the same as Experimental Example 1.

Experimental Example 5

45 wt% molasses, 30 wt% of caramel, and 25 wt% of water were mixed with respect to the total binder weight. The remaining experimental procedure was the same as Experimental Example 1.

Experimental Example 6

30 wt% molasses, 45 wt% of caramel, and 25 wt% of water were mixed with respect to the total binder weight. The remaining experimental procedure was the same as Experimental Example 1.

Comparative Example 1

Caramel was not added, and only 75 wt% molasses and 25 wt% of water were used as a binder. The remaining experimental procedure was the same as Experimental Example 1.

Comparative Example 2

Molasses was not added, and only 75 wt% of caramel and 25 wt% of water were used as a binder. The remaining experimental procedure was the same as Experimental Example 1.

Strength Evaluation Experiment

The molded briquettes were dried at room temperature for 1 hour, and 30 of the briquettes were fixed at the bottom, and the maximum load was measured until the briquettes were pressed at a constant speed at the top. The average values are shown in Table 1 below.

Evaluation of shape defect rate

The shape defectiveness is evaluated when the ball having a diameter of 1 cm or more out of 200 manufactured bellows is separated from the briquette, and the defective shape ratio is shown in Table 1 below.

Binder (wt%) burglar
(kgf) Defect ratio
(%) molasses Caramel water Experimental Example 1 71 4 25 90 3 Experimental Example 2 68 7 25 90 2.5 Experimental Example 3 64 11 25 90 2 Experimental Example 4 60 15 25 90 2 Experimental Example 5 45 30 25 70 One Experimental Example 6 30 45 25 70 One Comparative Example 1 75 0 25 90 3 Comparative Example 2 0 75 25 65 0.5

As shown in Table 1, it was found that the shape-defective rate of the briquettes produced in Experimental Examples 1 to 6 was lower than that of the briquettes prepared in Comparative Example 1. [ In addition, it can be seen that the briquettes produced in Experimental Examples 1 to 6 have higher strength than the briquettes prepared in Comparative Example 2. Further, the briquettes produced in Experimental Examples 2 to 4 were lower than those of the briquettes prepared in Comparative Example 1 in terms of strength and defective ratio at the same time.

The molded carbon produced according to Comparative Example 1 was partially adhered to the surface of the roll, and thus the shape of the molded carbon was poor. In contrast, in the case of mixing molasses and caramel together as a binder in Experimental Examples 1 to 6, the molded carbon was not adhered to the surfaces of the twin rolls, so that defective shape of the molded carbon was suppressed.

Therefore, it was confirmed that the molded bellows produced according to Experimental Examples 1 to 6 can obtain excellent strength while suppressing shape defects during the manufacturing process.

Inverse Analysis of Binder Components of Molded Carbon

100 g of the molded coal produced in Experimental Example 1 was finely pulverized. Then, 500 ml of ethanol was added. The liquid portion was decanted and separated from the coal. The separated liquid was filtered to separate the solid portion. The liquid contained in the filtered solid portion was removed using a rotary evaporator, and the remaining portion was made into an aqueous solution of 0.1 wt%. This was analyzed with a UV spectrometer in a 10 mm cell. As a result, a band near 610 nm and an absorption rate of 0.15 to 2.0 were measured. As a result, it was understood that caramel was mixed. The concentration of sucrose was determined by liquid chromatography (HPLC).

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.

10. Melting and gasification furnace
20, 22. Reduction furnace
30. Tungus
40. Reduction iron compression unit
50. Compressed reduced iron storage tank
100, 200. 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 with a binder to prepare a mixture, and
Molding the mixture to produce molded-in-
Lt; / RTI >
In the step of producing the mixture, the binder includes molasses, caramel, and water. The method according to claim 1,
In the step of producing the mixture, the binder comprises 10 wt% to 75 wt% molasses, 2 wt% to 20 wt% of caramel, and the balance water. 3. The method of claim 2,
Wherein the amount of molasses is from 50 wt% to 70 wt%, and the amount of caramel is from 5 wt% to 20 wt%. The method according to claim 1,
Wherein the caramel is produced from a sugar by a caramelization reaction in the step of producing the mixture. The method according to claim 1,
In the step of producing the mixture, the amount of the binder to the mixture is 3 wt% to 12 wt%. The method according to claim 1,
In the step of producing the mixture, the curing agent is further mixed into the mixture, and the amount of the curing agent is 1 wt% to 5 wt% of the mixture. delete delete delete

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