KR101709202B1 - Method and apparatus for manufacturing coal briquettes - Google Patents

Abstract

The method for producing molded coal according to an embodiment of the present invention includes a step of preparing coal, a step of drying coal, a step of measuring moisture after drying to measure the content of water contained in the dried coal, a step of drying coal, Mixing at least one of the binders to provide a mixture, and molding the mixture to produce a molded charcoal. In the step of providing the mixture, water is added so as to reach a target value of a predetermined moisture content from the moisture content measured in the moisture measurement step after drying.

Description

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

To a method of manufacturing a molded carbon and an apparatus for manufacturing the molded carbon. More specifically, the present invention relates to a method of manufacturing a shaped coal with reduced cold strength variation and an apparatus for producing the shaped coal.

In the melt reduction steelmaking method, a reduction furnace for reducing iron ore and a melter-gasifier for melting reduced iron ore are 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.

Since a large amount of briquettes is required for mass production of molten iron, the briquettes produced are outdoors. In this case, since the briquette can be broken by an external impact, it is necessary to increase the cold strength of the briquette. Further, when the variation of the cold strength of the briquette is large, fluctuation of the cold strength of the briquetted coal is required to be reduced because operation fluctuation in the melter-gasifier can be caused.

A method of manufacturing a shaped coal having excellent cold strength and a reduced variation in cold strength, and an apparatus for producing a molded coal.

The method for producing molded coal according to an embodiment of the present invention includes a step of preparing coal, a step of drying coal, a step of measuring moisture after drying to measure the content of water contained in the dried coal, a step of drying coal, Mixing at least one of the binders to provide a mixture, and molding the mixture to produce a molded charcoal. In the step of providing the mixture, water is added so as to reach a target value of a predetermined moisture content from the moisture content measured in the moisture measurement step after drying.

Drying step for measuring the content of water contained in the prepared coal prior to the step of drying the coal.

In the step of drying the coal, it may be dried to contain 4 to 7% by weight of water relative to 100% by weight of the total coal.

The target value may be 7 to 8 wt% of water based on 100 wt% of coal.

The step of mixing at least one of the dried coal, the hardener and the binder to provide a mixture comprises: mixing the dried coal with a curing agent to provide a first mixture; and mixing the first mixture and the binder to provide a second mixture , And in the step of providing the second mixture, water may be added so as to reach a target value of a predetermined moisture content from the measured moisture content.

The step of preparing the coal may further include a step of crushing the coal.

The apparatus for producing molded coal according to an embodiment of the present invention comprises a coal storage tank for storing coal, a dryer for drying coal, a dryer posterior moisture measuring device installed at the downstream end of the dryer, a hardener storage tank for storing the hardener, A mixer that mixes the binder supplied from the binder storage tank, the dried coal provided from the dryer, the hardener provided from the hardener storage tank, and the binder provided from the binder storage tank, a water supply nozzle installed in the mixer, and a signal from the dryer posterior moisture measurement device A control unit for controlling the moisture supply nozzle so that the moisture content reaches a predetermined target value, and a molding machine for molding the mixture by receiving the mixture from the mixer.

A plurality of water supply nozzles may be installed in the mixer.

And a dryer front-end moisture measuring device installed at the front end of the dryer.

And a dryer control unit for receiving a signal from the dryer shear moisture measuring device and controlling the amount of heat of the dryer so that the moisture content reaches 4 to 7 wt% of water with respect to 100 wt% of the total coal.

The mixer includes a first mixer and a second mixer, wherein the first mixer is connected to the hardener reservoir, the second mixer is connected to the binder reservoir, and the moisture supply device is installed in the second mixer.

And a crusher for crushing coal between the coal storage tank and the drier.

The control unit can control the target value to include 7 to 8% by weight of water with respect to 100% by weight of coal.

By keeping the moisture contained in the coal constant, it is possible to reduce the deviation of the cold strength of the molded coal. In addition, by minimizing the rapid deviation of cold strength due to moisture fluctuation, the fuel cost in the melter-gasifier for charcoal production can be reduced.

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 an apparatus for producing a blast furnace according to an embodiment of the present invention. FIG.
FIG. 3 is a schematic view of an apparatus for producing a blast furnace according to another embodiment of the present invention. FIG.
FIG. 4 is a schematic view of a molten iron manufacturing apparatus using the shaped coal produced in FIG. 1. FIG.
FIG. 5 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 a step of preparing coal (S10), a step of drying coal (S20), a step of measuring the content of water contained in the dried coal (S30) (S40) mixing at least one of coal, a curing agent and a binder to provide a mixture, and molding the mixture to form a blast (S50). In step S40 of providing the mixture, moisture is added so that the moisture content reaches a predetermined target value. In addition, if necessary, the method of manufacturing the molded coal may further include other steps.

First, in step S10, coal is prepared. Generally, coal is classified into peat having a carbon content of about 60%, coal and coal, about 70% to 80% of coal, about 80% to 90% of bituminous coal and 90% or more of anthracite. The type of coal is not particularly limited, and may be a single coal or a mixture of various coal.

After step S10, the step of crushing the coal may be further included. In order to reduce variation in quality, the crushed coal particles can be crushed to have a uniform particle size. As a specific criterion, the crushed coal particles can be crushed to have a particle size of 5 mm or less at 90 wt% to 100 wt%.

Next, in step S20, the coal is dried. In the step of drying the coal, it may be dried to contain 4 to 7% by weight of water relative to 100% by weight of the total coal.

More specifically, before step S20, it may further include a pre-drying moisture measurement step of measuring the moisture content of the coal prepared in step S10. The moisture content in the dried coal can be controlled by adjusting the amount of drying heat or the drying time in step S20 from the moisture content measured in the moisture measuring step before drying. The amount of moisture measured in step S30 to be described later may be fed back to adjust the drying heat amount or the drying time.

As a method of measuring the water content of the coal prepared in the moisture measurement step before drying, a method of measuring the moisture content of the coal by using a microwave irradiation type moisture meter or manually sampling the coal directly using a manpower can be used. The method of using the microwave irradiation type moisture meter can be measured in real time, but there is a problem that the reliability is not high due to the sensitive response by the conditions such as the particle size of the coal and the density of the coal. In the case of using a workforce, there is a deviation between the workers, which causes a work load of the worker. Therefore, when the coal is dried in step S20 and no water is added in step S40 described later, the variation in moisture content between coals becomes large.

Next, step S30 is a post-drying moisture measurement step for measuring the content of water contained in the dried coal. Specifically, as a method for measuring the moisture content of dried coal, there can be used a continuous measurement system of a microwave irradiation type widely used as a conventional moisture meter or a method of periodically measuring sampled coal manually dried by a worker into a dryer have.

Next, in step S40, one or more of the dried coal, the hardener and the binder are mixed to provide a mixture.

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. The amount of the curing agent may be from 1 wt% to 5 wt% with respect to the whole mixture. When the amount of the curing agent is too small, the binder and the curing agent are not sufficiently bonded to each other, and the strength of the formed cured 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.

As the binder, molasses, raw sugar, cellulose, starch or bitumen can be used. The amount of binder may be from 3 wt% to 15 wt% of the total 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.

In step S40, moisture is added so that the moisture content reaches a predetermined target value. Concretely, from the content of the moisture measured in the step S30, the deficiency moisture is added so as to reach the predetermined target value. At this time, the predetermined target value includes 7 to 8 wt% of water with respect to 100 wt% of the total coal. If the content of water in the coal is too small, sufficient cold strength may not be exhibited. In addition, if the content of water in the coal is too high, it is difficult to supply normally with a forming roll in a feeding device, and a low-density pear-molded coal may be generated, or a problem of adhesion of the pulverized coal may occur in the forming roll. Therefore, the target value is adjusted to the above-mentioned range.

Step S40 may comprise providing the first mixture by mixing the dried coal and the curing agent, and mixing the first mixture and the binder to provide the second mixture. Thus, a more uniform mixture can be prepared by dividing the mixing step into two steps.

In the case of dividing step S40 into two stages, water may be added in the step of providing the second mixture in order to further reduce the deviation of the moisture content between coals.

Finally, in step S50, the mixture is molded to produce a blast furnace. When the step (S40) is divided into two steps and mixed, the second mixture is molded to produce the shaped coal. Although not shown in FIG. 1, the mixture may be charged between two pairs of rolls rotating in mutually opposite directions to produce molded pellets or strips of shaped coal. As a result, it is possible to produce briquette having excellent hot strength and cold strength.

Fig. 2 schematically shows an apparatus for producing a blast furnace according to an embodiment of the present invention. The apparatus for producing a molded coal of Fig. 2 is merely for illustrating the present invention, and the present invention is not limited thereto. Therefore, the apparatus for manufacturing a briquette can be variously modified.

2, the apparatus for producing molded coal includes a coal storage tank 10 for storing coal, a drier 40 connected to the coal storage tank 10 for drying the coal, a dryer 40 installed downstream of the drier 40, A moisture measuring device 50, a hardening agent storage tank 20 in which a hardening agent is stored, a binder storage tank 30 in which a binder is stored; A mixer 60 for mixing the dried coal provided from the dryer 40, the curing agent provided from the hardener reservoir 20 and the binder provided from the binder storage tank 30 to provide a mixture; A control unit 80 for receiving a signal from the moisture supply nozzle 70 and the dryer rear end moisture measurement device 50 provided in the mixer 60 and controlling the moisture supply nozzle 70 so that the moisture content reaches a predetermined target value, ; And a molding machine (90) for molding the mixture by receiving the mixture from the mixer (60). The specific structure and operation method of each device included in the apparatus for producing a molded-in-Figure 2 can be easily understood by those skilled in the art, and thus a detailed description thereof will be omitted.

The coal storage tank 10 stores coal. Generally, coal is classified into peat having a carbon content of about 60%, coal and coal, about 70% to 80% of coal, about 80% to 90% of bituminous coal and 90% or more of anthracite. The type of coal is not particularly limited, and may be a single coal or a mixture of various coal.

A crusher may be additionally provided between the coal storage tank 10 and the dryer 40. The crusher can crush the crushed coal particles so that the particle size of the crushed coal particles is constant, and as a specific criterion, the crusher can be crushed so that the particle size of 5 mm or less is 90 wt% to 100 wt%.

The dryer 40 is connected to the coal storage tank 10 to dry the coal supplied from the coal storage tank 10. When the crusher is installed between the coal storage tank 10 and the drier 40, the coal supplied from the crusher is dried.

A dryer front end moisture measurement device for measuring the moisture content of the stored coal may be further provided at the front end of the dryer 40, and a dryer control unit for controlling the heat amount of the dryer 40 may further be provided. The dryer control unit receives a signal from the dryer front end moisture measurement device and can control the amount of heat of the dryer so that the moisture content of the coal contains 4 to 7% by weight of water based on 100% by weight of the total coal. The dryer controller can control the amount of heat of the dryer 40 by receiving the feedback from the dryer rear end moisture measurement device 50 to be described later together with the dryer front end moisture measurement device.

At the downstream end of the dryer (40), a dryer rear end moisture measurement device (50) for measuring the moisture content of the dried coal is installed. The dryer posterior moisture measurement device 50 is not particularly limited, but it may be a microwave irradiation type continuous moisture meter commonly used for moisture measurement, a continuous moisture meter using infrared or neutron, or a moisture meter Etc. may be used. The moisture content measured by the dryer posterior moisture measurement device 50 is transmitted to the control unit 80. The control unit 80 receives a signal from the dryer posterior moisture measurement device 50 and the moisture content reaches a predetermined target value So as to control the water supply nozzle 70. In this case, the target value includes 7 to 8% by weight of water with respect to 100% by weight of the total coal.

The mixer 60 mixes the dried coal provided from the dryer 40, the hardener provided from the hardener reservoir 20 and the binder provided from the binder reservoir 30 to provide a mixture. Also, a water supply nozzle 70 is provided in the mixer 60, and the water supply nozzle 70 adds moisture to the water so that the water content in the coal reaches a target value. In order to uniformly supply moisture to the coal in the mixer 60, a plurality of water supply nozzles 70 may be provided.

The mixer 60 is provided from a first mixer 61 and a first mixer 61 which mix the dried coal provided from the dryer 40 and the hardener provided from the hardener reservoir 20 to provide a first mixture, And a second mixer 62 that mixes the first mixture with the binder provided from the binder reservoir 30 to provide a second mixture. Accordingly, the first mixer 61 is connected to the hardener storage tank 20, and the second mixer 62 is connected to the binder storage tank 30.

FIG. 3 schematically shows an apparatus for producing a blast furnace according to another embodiment of the present invention, and shows an example in which the mixer 60 includes a first mixer 61 and a second mixer 62. In the case where the first mixer 61 and the second mixer 62 are included, the moisture supply nozzle 70 may be installed in the second mixer 62 to further reduce the variation in moisture content between coals.

The molding machine 90 receives the mixture from the mixer 60 and shapes the mixture. Specifically, the molding machine 90 is composed of twin rolls rotating in mutually opposite directions, and the mixture may be charged between the twin rolls to form a pocket or a strip.

Fig. 4 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. 4 is merely for illustrating the present invention, and the present invention is not limited thereto. Therefore, the molten iron manufacturing apparatus 100 of FIG. 4 can be modified into various forms.

The molten iron manufacturing apparatus 100 of FIG. 4 includes a melter-gasifier 110 and a reduction furnace 120. Other devices may also 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 furnace, and is supplied with a reducing gas from the melter-gasifier furnace 110.

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. 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 briquette produced by the manufacturing method of FIG. 1 can minimize the rapid variation in cold strength due to moisture variation, and can reduce the fuel cost in the melter-gasifier 110.

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. 5 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. 5 is merely for illustrating the present invention, and the present invention is not limited thereto. Therefore, the molten iron manufacturing apparatus 200 of FIG. 5 can be modified into various forms. Since the structure of the molten iron manufacturing apparatus 200 of FIG. 5 is similar to that of the molten iron manufacturing apparatus 100 of FIG. 4, the same reference numerals are used for the same parts, and a detailed description thereof will be omitted.

5, the molten iron manufacturing apparatus 200 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, preferred embodiments and comparative examples of the present invention will be described. However, the following examples are only a preferred embodiment of the present invention, and the present invention is not limited to the following examples.

Example

The moisture content of the prepared coal was measured in real time using a microwave irradiation type moisture meter and the amount of heat was adjusted according to the measured result. At this time, the amount of heat was adjusted so that the content of moisture was close to 6.5 wt% with respect to 100 wt% of the whole coal. The dried coal was measured for moisture content in real time using a microwave irradiation type moisture meter. The dried coal was mixed with CaO as a curing agent in an amount of 3% by weight based on 100% by weight of the total mixture, and molasses as a binder was mixed with 100% Based on the result of the measurement of the moisture content of the dried coal in the binder mixture, the target value of the water content is adjusted to 7.5% by weight based on 100% by weight of the total coal, Respectively. The mixture was compressed by a roll press to produce briquetted shaped briquettes.

A sample was taken at each step and the moisture content was measured. The results are shown in Table 1 below.

Moisture content in raw coal
(weight%) Moisture content in coal immediately after drying
(weight%) Moisture content in pre-molding coal
(weight%) Sample 1 7.5 5.10 7.42 Sample 2 8.9 6.84 7.53 Sample 3 8.3 6.07 7.48 Sample 4 8.0 5.29 7.45 Sample 5 9.0 7.03 7.61

As shown in Table 1, the deviation of the moisture content in the coal immediately after drying is relatively large, but it is confirmed that the moisture content in the coal before molding is relatively small after the water is added in the binder mixing process.

Comparative Example

The moisture content of the prepared coal was measured in real time using a microwave irradiation type moisture meter and the amount of heat was adjusted according to the measured result. At this time, the amount of heat was adjusted so that the moisture content was close to 7.5 wt% with respect to 100 wt% of the whole coal. 3% by weight of CaO as a curing agent was mixed with 100% by weight of the whole mixture, and 10% by weight of molasses was mixed as a binder with respect to 100% by weight of the whole mixture. The mixture was compressed by a roll press to produce briquetted shaped briquettes.

A sample was taken at each step and the moisture content was measured. The results are shown in Table 2 below.

Moisture content in raw coal
(weight%) Moisture content in coal immediately after drying
(weight%) Moisture content in pre-molding coal
(weight%) Sample 1 8.6 7.5 7.40 Sample 2 9.1 7.2 7.69 Sample 3 7.5 7.0 7.10 Sample 4 7.9 6.9 7.03 Sample 5 7.7 8.0 7.82

As shown in Table 2, the average of the moisture content in the pre-molding coal is similar to that of the embodiment, but it can be confirmed that the variation of the moisture content is relatively large as compared with the embodiment.

Experimental Example: Evaluation of Cold Strength

5 boxes were arbitrarily selected for each of the examples and comparative examples, and the maximum load was measured until the bottom was fixed and pressed at a constant speed at the top to be destroyed. The results are shown in Table 3 below.

Example
(kgf) 331 325 340 314 309 Comparative Example
(kgf) 345 366 310 286 301

As shown in Table 3, the average values of the cold strengths of the briquettes prepared in Examples and Comparative Examples were similar, but the variation in cold strength was small in the briquettes produced in Examples, while the briquettes prepared in Comparative Example had a variation in cold strength .

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: Coal reservoir 20: Hardener reservoir
30: binder storage tank 40: dryer
50: dryer posterior moisture measurement device 60: mixer
61: first mixer 62: second mixer
70: water supply nozzle 80:
90: Molding machine 110: Melting-gasifier
120, 122: reduction furnace 130: tungsten
140: Reduction iron compactor 150: Compressed reduction iron storage tank
100, 200: Molten iron manufacturing apparatus 101: Dome unit

Claims (13)

A melter-gasifier furnished with reduced iron, and
A reducing furnace connected to the melter-gasifier and supplied with a reducing gas from the melter-gasifier and providing the reduced iron to the melter-
Wherein the molten iron is charged into a dome portion of the melter-gasifying furnace and rapidly heated to generate a reducing gas,
Preparing coal;
Drying the coal to a moisture content of 4 to 7 wt% based on 100 wt% of the total coal;
Drying moisture measurement step of measuring the moisture content of the dried coal;
Mixing at least one of the dried coal, a hardener and a binder to provide a mixture; And
Molding the mixture to produce a shaped coal;
Lt; / RTI >
In the step of providing the mixture, moisture is added so as to reach a target value of a predetermined moisture content from the moisture content measured in the moisture measurement step after the drying, and the target value is set to a moisture content of 100% 7 to 8% by weight. The method according to claim 1,
Further comprising a pre-drying moisture measurement step of measuring a content of water contained in the prepared coal prior to the step of drying the coal. delete delete The method according to claim 1,
The step of providing a mixture by mixing at least one of dried coal, a hardener and a binder includes the steps of mixing the dried coal and the hardener to provide a first mixture, and mixing the first mixture and the binder to form a mixture 2 < / RTI > mixture,
In the step of providing the second mixture, water is added so as to reach a target value of a predetermined moisture content from the measured moisture content. The method according to claim 1,
Further comprising the step of crushing the coal after the step of preparing the coal. A melter-gasifier furnished with reduced iron, and
A reducing furnace connected to the melter-gasifier and supplied with a reducing gas from the melter-gasifier and providing the reduced iron to the melter-
Wherein the molten iron is charged into a dome of the melting and gasifying furnace and rapidly heated to generate a reducing gas,
A coal reservoir for storing coal;
A dryer connected to the coal storage tank for drying the coal;
A dryer rear end moisture measurement device provided at a downstream end of the dryer;
A curing agent reservoir containing a curing agent;
A binder storage tank in which a binder is stored;
A mixer for mixing the dried coal provided from the dryer, the curing agent provided from the hardener reservoir, and the binder provided from the binder storage tank to provide a mixture;
A water supply nozzle installed in the mixer;
A controller for receiving a signal from the dryer rear end moisture measurement device and controlling the moisture supply nozzle so that the moisture content reaches a predetermined target value;
A molding machine for receiving the mixture from the mixer and molding the mixture;
A dryer front end moisture measurement device installed at a front end of the dryer; And
A dryer control unit receiving a signal from the dryer front end moisture measurement device and controlling the amount of heat of the dryer so that the moisture content reaches 4 to 7 wt% of water with respect to 100 wt% of the total coal;
Lt; / RTI >
Wherein the control unit controls the target value to include 7 to 8 wt% of water with respect to 100 wt% of the total coal. 8. The method of claim 7,
Wherein a plurality of the water supply nozzles are provided in the mixer. delete delete 8. The method of claim 7,
Wherein the mixer includes a first mixer and a second mixer,
The first mixer is connected to the hardener reservoir,
The second mixer is connected to the binder reservoir,
And the water supply nozzle is installed in the second mixer. 8. The method of claim 7,
And a crusher for crushing coal between the coal storage tank and the drier. delete

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