KR101405478B1 - Method for manufacturing coal bruquettes and apparatus for the same - Google Patents

Abstract

Provided are a coal briquette manufacturing method and a coal briquette manufacturing apparatus with which coal can be separated and pulverized into types and excellent cold strength and hot strength can be acquired. The coal briquette manufacturing method is applied for charging in a dome portion of a molten gas furnace and for rapid heating in a molten iron manufacturing apparatus that includes i) the molten gas furnace in which reduced iron is charged; and ii) a reduction furnace that is connected to the molten gas furnace to provide the reduced iron. The coal briquette manufacturing method includes i) a step for providing a plurality of types of coal; ii) a step for individually storing the plurality of types of coal; iii) a step for providing powdered coal by individually pulverizing the plurality of types of coal; iv) a step for providing a mixture by mixing the powdered coal, a curing agent, and a binder; and v) a step for providing a coal briquette by molding the mixture.

Description

[0001] METHOD FOR MANUFACTURING COAL BRUQUETTES AND APPARATUS FOR THE SAME [0002]

The present invention relates to a method of manufacturing a molded coal and an apparatus for producing a molded coal. More particularly, the present invention relates to a method for producing molded coal and an apparatus for producing molded coal, which can separate and break coal by the type of coal, thereby realizing excellent cold strength and hot strength.

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.

In the case of using the blast furnace, it is necessary to increase the production amount of molten iron and to reduce the fuel cost to make the molten iron manufacturing process more efficient. For this purpose, the amount of differentiation within the melting and gasification furnace of the shaped coal is reduced, and the blast furnace must be maintained at a large particle size in the melting gasification furnace. In this case, it is possible to ensure the air permeability and the liquid permeability through which the gas and the liquid smoothly pass through the melting and gasifying furnace, thereby increasing the reaction efficiency and the heat transfer efficiency between the respective materials. In addition, it is possible to reduce the amount of fine powder that can not be efficiently used at the time of manufacturing molten iron due to differentiation. There is a limit in reducing the amount of generation of fine powder by mixing various coal.

The present invention provides a method for producing molded coal which is capable of realizing excellent cold strength and hot strength by separating and crushing coal according to the type of coal. Further, it is intended to provide an apparatus for producing molded coal, which can separate and break the coal by each type of coal to realize excellent cold strength and hot strength.

A method for producing a molten steel according to an embodiment of the present invention includes the steps of: i) a melter-gasifier furnished with reduced iron; and ii) a reducing furnace connected to the melter- To be heated rapidly. The method for producing molded coal includes the steps of i) providing coal of a plurality of types of seeds, ii) storing each of the plurality of coal types individually, iii) separately crushing the plurality of coal types of the seeds to provide pulverization And iv) mixing the powder, the hardener and the binder to provide a mixture, and v) molding the mixture to provide the blast furnace.

The method for manufacturing the briquette according to an embodiment of the present invention may further include the step of drying the pulverized coal together. The moisture standard deviation of the pulverized coal may be 0.3 or less. In the step of providing the coals of a plurality of types of coal, the coal of the seeds having a difference of HGI (Hardgrove Grindability Index) among the coals of the plurality of types of coal can be supplied together. The difference in the HGI index among the coal of the plurality of types of coal may be 5 or less.

The step of providing the mixture may include the steps of i) uniformly mixing the coal, and ii) providing a binder and a curing agent to the uniformly mixed coal and mixing them together. In the step of providing the pulverized coal, the particle size of the pulverized coal may be greater than 0 and less than 5 mm. The particle size of the pulverized coal may be from 1 mm to 3 mm.

In the step of providing the coal, the coal of the plurality of types of coal includes the first coal and the second coal, and the crushing time of the first coal may be different from the crushing time of the second coal. The crushing time of the first coal is longer than the crushing time of the second coal and the cohesion of the first coals may be lower than the cohesion of the second coals.

An apparatus for producing molded coal according to an embodiment of the present invention comprises i) a plurality of coal reservoirs for storing coal of a plurality of types of seeds, ii) a plurality of coal reservoirs connected to each of the plurality of coal reservoirs, V) a binder provided from a binder reservoir, and a curing agent provided from a curing agent reservoir are mixed with each other to form a curing agent reservoir, c) a curing agent reservoir, A mixer providing the mixture, and vi) a molding machine for receiving the mixture from the mixer and molding the mixture. The apparatus for producing molded coal according to an embodiment of the present invention may further include a dryer connected directly to the plurality of crushers to dry the crushers together.

The coal is separately crushed and dried by the type of the coal, and then the briquette is produced, so that the cold strength and the hot strength of the briquetted coal to be produced can be improved. Therefore, it is possible to increase the size and strength of the molten steel obtained by rapidly pyrolyzing the blast furnace in the melter gasification furnace, thereby improving the operating efficiency and fuel cost in the molten iron manufacturing process. In addition, it is possible to use a low-cost coal having low crushability as a raw material for the briquette and reduce the amount of the binder used.

Fig. 1 is a schematic flow chart of a method of manufacturing a briquette according to an embodiment of the present invention.
2 is a schematic view of an apparatus for producing a briquette according to an embodiment of the present invention.
FIG. 3 is a schematic view of a molten iron manufacturing apparatus connected to the apparatus for producing molded coal of FIG. 2. FIG.
FIG. 4 is a schematic view of another molten iron manufacturing apparatus connected to the apparatus for producing molded coal of FIG. 2. 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.

As used herein, the term "HGI " is used as a measure of the resistance of coal to fracture as a Hardgrove Grindability Index. For example, HGI puts 50 grams of a prepared coal sample into a grinding unit, processes the unit at a specified number of revolutions at a specified pressure, breaks the coal sample into steel balls in the unit, classifies the coal particles, Is recorded and converted into the HGI value.

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 method for producing 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 molded-on-carbon can be variously modified.

As shown in FIG. 1, a method of manufacturing a molded coal includes the steps of providing coal of a plurality of types of seeds (S10), individually storing each of the plurality of coal types of the seeds (S20) (S30), separately mixing crushed coal, a hardener and a binder to provide a mixture (S40), and molding the mixture to provide a blast (S50). In addition, if necessary, the method of manufacturing the molded coal may further include other steps.

First, in step S10, coal of a plurality of types of seeds is provided. For example, anthracite coal, coking coal, semi-anthracite coal, uncoated coal, and the like may be used as the coal necessary for producing the molded coal. Raw manganese may contain a large amount of volatile matter. Meanwhile, although not shown in FIG. 1, the quality control coal can be mixed together in the pulverizer to improve the quality of the molten iron. Here, as the coal for quality control, coal having a reflectance higher than a predetermined value can be used.

The size distribution range of the coal of the plurality of types of coal is as large as 0 and less than 50 mm. On the other hand, coal has different HardGrove Grindability Index (HGI) depending on its degree of carbonization. Lignite or bituminous coal with a low degree of carbonization has a low HGI, bituminous coal has a high HGI, and anthracite with the highest degree of carbonization has a low HGI again.

In step S20, coal of a plurality of seeds is individually stored. When coal of a plurality of types of coal is mixed and stored, there is a bad influence on the quality of the coal to be produced in the subsequent process owing to the grain size deviation and moisture deviation. Therefore, the coal of the plurality of seeds is separated and stored separately from each other.

Next, in step S30, coal of a plurality of types of seeds is individually crushed to provide pulverization. That is, the coal of a plurality of types of seeds is separately crushed. For example, the average grain size of coal of a plurality of types of coal can be adjusted to 5 mm or less. If the average grain size of the coal of the plural types of coal is larger than 5 mm, the quality of the coal may be deteriorated because it is difficult to uniformly mix the coal of the plurality of coal types in the subsequent process. Thus, the average particle size of the coal of the plurality of types of coal is adjusted to the above-mentioned range. Preferably, the average particle size of the coal can be controlled to be 1 mm to 3 mm.

The coals of the plurality of seeds may have mutually different HGI. For example, the difference in HGI of coal of a plurality of types of coal may be 10 or less. When the HGI difference is too large, it is unsuitable as a raw material for coal for producing a briquette. Therefore, the difference of HGI is adjusted to the aforementioned range. Preferably, the difference in HGI may be 5 or less.

On the other hand, since the coal of a plurality of types of seeds having mutually different HGIs is crushed separately, the crushing times of the coal of the plurality of seeds can be mutually different. That is, coals having a low HGI are not crushed into fine particles, so that the crushing time is longer. On the contrary, since high HGI coal is crushed well, the crushing time can be reduced. On the other hand, since highly cohesive coal is crushed well, the higher the degree of cohesion, the longer the crushing time.

Conventionally, coal of various types of coal is dried together and then crushed in a crusher. In this case, the particle size of the coal varies depending on the difference in the strength of the coal, and thus the particle size distribution of the coal mixed with the coal is greatly expanded. Therefore, not only is the moisture content of the mixed coal large, but also the grain size is difficult to control due to the wide particle size distribution due to the different HGI, and it is difficult to control the particle size when changing the blend ratio of coal to coal. As a result, the hot quality and the cold quality of the briquettes produced in the subsequent process can be adversely affected. On the other hand, in one embodiment of the present invention, coal of each seed burnt is separately crushed and then mixed together, so that the particle size distribution is narrowed. Here, the crushing of coal is carried out by changing the capacity of the crusher, the crushing condition, and the crushing speed. As a result, not only the moisture deviation of the mixed carbon is small, but also the mixed carbon has a uniform particle size, so that the molded carbon having excellent characteristics can be produced.

On the other hand, although not shown in Fig. 1, the mixed coal, which is obtained by separately pulverizing the pulverized coal, can be dried. In this case, since the coal having a uniform particle size is dried, the moisture deviation of the mixed coal can be minimized. Therefore, the moisture content and the moisture deviation of the mixed carbon can be appropriately controlled, so that the quality of the molded coal can be further improved. For example, the moisture standard deviation of blended coal mixed with coal can be adjusted to 0.3 or less. If the moisture standard deviation of the mixed coals is too large, the amount of moisture contained in the mixed coals is not constant, which deteriorates the quality of the briquettes.

Conventionally, after the coal is dried, the water content of the coal is automatically controlled to be the target value. In this case, for automatic control, many parameters such as the amount of coal to be dried, the drying temperature of the coal dryer, the amount of air, and the water content of the coal before drying have to be considered. In addition, in the case of measuring moisture, in order to increase the accuracy of the measured value, the amount of the sample for moisture measurement must be large, and the sample must be sampled uniformly. Therefore, it becomes increasingly difficult to collect and dry mechanical samples for automatic measurement of coal moisture. Therefore, it becomes difficult to cope with the moisture change of the coal before the coal is dried, so that automatic moisture control becomes impossible. In contrast, in an embodiment of the present invention, since the coal is crushed to make the grain size uniform and then the coal is dried, the drying process of the coal is simplified.

Next, in step S40, the crushed coal, the hardener and the binder are mixed to provide a mixture. Here, the crushed coal, graphite, hardener and binder may be mixed in any order, or the specific raw materials may be mixed first. For example, the hardeners may be mixed after first mixing the crushed coal and the binder. Alternatively, the hardeners may be mixed after the crushed coal and hardener are first mixed.

As the hardening agent, it is possible to use quicklime, slaked lime, metal oxide, fly ash, clay, surfactant, cationic resin, accelerator, fiber, phosphoric acid, sludge, waste plastics, waste lubricating oil, waste toner, graphite or activated carbon . As the binder, molasses, starch, sugar, polymer resin, pitch, tar, bitumen, oil, cement, asphalt or water glass can be used. For example, when molasses is used as a binder and burnt lime is used as a hardening agent, the cold strength of the briquette can be greatly improved by the saccharide bonding during the production of the briquette.

On the other hand, in step S40, the mixture may be firstly uniformly mixed, and then a binder and a curing agent may be provided to provide a mixture. That is, since the pulverized coal includes various types of coal, if the pulverized coal is not uniformly mixed, the quality of the coal may be deteriorated. Therefore, prior to feeding the binder and curing agent to the coal, the coal is first mixed uniformly.

Finally, in step S50, the mixture is molded to provide a blast furnace. For example, the blend can be continuously compressed using a molding machine including a pair of forming rolls to produce a blast furnace.

2 schematically shows an apparatus 100 for producing molded articles according to an embodiment of the present invention. The apparatus 100 for producing molded articles of Fig. 2 is merely for illustrating the present invention, and the present invention is not limited thereto. Therefore, the structure of the apparatus 100 for forming a molded product can be variously modified.

2, the apparatus for producing molded articles 100 includes a coal storage tank 10, a crusher 20, a binder storage tank 40, a hardening agent storage tank 50, a mixer 60 and a molding machine 70 . In addition, the apparatus for producing molded articles of the present invention further includes a dryer 90, a mixed carbon storage tank 92, a recovered carbon storage tank 94, and a particle size separator 805. The molding machine manufacturing apparatus 100 may further include other devices as needed. The specific structure and operation method of each apparatus included in the apparatus 100 for producing molded articles shown in FIG. 2 can be easily understood by those skilled in the art, and thus a detailed description thereof will be omitted.

A plurality of coal reservoirs (10) each store coal of a plurality of seeds. For example, in addition to coal used as a raw material for the briquettes, quality control coal may be used to improve the quality of the briquette. Accordingly, a plurality of coal storage tanks 10 are installed separately for mixing an appropriate amount of quality control coal according to the amount of coal used as a raw material.

Each of the plurality of crushers 20 is connected to a plurality of coal reservoirs 10, respectively. A plurality of crushers 20 receives coal from different coal stocks 10 from a plurality of coal stockpiles 10 and crushes them. For example, coal can be crushed to provide coal as a powder having a particle size of 8 mm or less. Although not shown in FIG. 2, the shredded pulverized coal may be provided directly to the mixer 60. Further, the crushed pulverized coal can be supplied to the mixer 60 after drying.

The dryer 90 dries the shredded coals together in each shredder 20. Accordingly, the pulverizers of the plurality of seeds may be mixed and dried in the dryer 90, and then may be supplied to the mixer 60.

As shown in FIG. 2, the binder is stored in the binder storage tank 40. The binders combine the fines of the plurality of seeds to make them suitable for the production of the briquettes. The binder reservoir 40 is connected to the mixer 60 to provide a binder to the mixer 60.

On the other hand, the curing agent is stored in the curing agent reservoir 50. The curing agent can be intermixed with the pulverizer and binder to optimize its strength by curing the briquettes. The hardener reservoir 50 is connected to the mixer 60 to provide the hardener to the mixer 60.

The mixer 60 mixes the powder, the binder, the curing agent, and the like to provide a mixture for producing the shaped coal. Before being supplied to the mixer 60, a plurality of seeds are stored together in the mixed carbon storage tank 92 and premixed, and mixed again and again uniformly in the mixer 60. Since the pulverized coal includes a plurality of seeds, the mixer 60 is first driven and homogeneously mixed before the binder and the hardener are put into the mixer 60. When the binder and the curing agent are directly introduced into the mixer 60, the pulverization of the plurality of seed burdens may not be uniformly mixed and the quality of the formed coal may be deteriorated. Thus, the mixers 60 first mix the coal blades of the plurality of types.

As shown in Fig. 2, the molding machine 70 includes a pair of rolls rotating in mutually opposite directions. The mixture is fed through a pair of rolls and the mixture is compressed by a pair of rolls to produce a blast furnace. On the other hand, the produced molded coal is classified again through the particle size separator 805 to store the coal in the recovered carbon storage tank 94. The pulverized coal stored in the recovered carbon storage tank 94 may be re-supplied to the mixer 60 and used as a raw material for the blast furnace. As a result, the utilization efficiency of the pulverized coal can be improved.

3 schematically shows a molten iron manufacturing apparatus 200 connected to the apparatus for producing molded coal 100 shown in Fig. 2 and using the briquettes produced in the apparatus for producing molded coal 100. 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 210 and a reducing furnace 220. In addition, the molten iron manufacturing apparatus 200 may include other devices as needed. In the reduction furnace 220, iron ore is charged and reduced. The iron ore charged in the reducing furnace 220 is pre-dried and then made into reduced iron through the reducing furnace 220. The reducing furnace 220 is a packed-bed reduction reactor, and a reducing gas is supplied from the melter-gasifier furnace 210 to form a packed bed therein.

3 is charged into the melter-gasifier 210 of FIG. 3, so that a coal-packed bed is formed in the melter-gasifier 210. A dome portion 2101 is formed on the upper portion of the melter-gasifier 210. There is a high-temperature reducing gas in the dome portion 2101 formed in a larger space than other portions of the melter-gasifier 210. The briquetted coal is charged into the dome portion 2101 of the melter-gasifier 210 and rapidly heated and dropped to the lower portion of the melter-gasifier 210. The ozone produced by the pyrolysis reaction of the briquettes moves to the lower part of the melter-gasifier 210 and exothermically reacts with oxygen supplied through the ozone 230. As a result, the briquettes can be used as a heat source for keeping the melter-gasifier 210 at a high temperature. The amount of gas generated in the lower portion of the melter-gasifier 210 and the reduced iron supplied from the reducing furnace 220 can more easily and uniformly pass through the coal packed bed in the melter- .

The lump gasification furnace 210 may be charged with lumpy carbonaceous material or coke as needed in addition to the above-mentioned shaped coal. A tuyere (230) is installed on the outer wall of the melter-gasifier (210) 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 another molten iron manufacturing apparatus 300 connected to the apparatus for producing molten iron 100 of Fig. 2 and using the molten iron produced by the apparatus for producing molten iron 100. 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 100 includes a melter-gasifier 210, a fluidized bed reduction reactor 310, a reduced iron compactor 320, and a compacted iron storage tank 330. Here, the compressed reduced iron storage tank 330 may be omitted.

The produced briquettes are charged into the melter-gasifier (210). Here, the blast furnace generates a reducing gas in the melter-gasifier 210, and the generated reducing gas is supplied to the fluidized-bed reduction reactor 310. The minute iron ores are supplied to the fluidized-bed reduction reactor 310 and are made of reduced iron while flowing by the reducing gas supplied from the melter-gasifier 210 to the fluidized-bed reduction reactor 310. The reduced iron is compressed by the reduced iron compactor 320 and then stored in the compacted iron storage tank 50. The compressed reduced iron is supplied to the melter-gasifier (210) from the compressed-reduced iron reservoir (330) and melted in the melter-gasifier (210). A large amount of gas generated in the lower portion of the melter-gasifier 210 and the compressed reduced iron are more easily and uniformly distributed in the melter-gasifier 210, So that a good quality molten iron can be produced. On the other hand, oxygen is supplied through the tuyere 230 to burn the blast furnace.

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

Experimental Example

Experiments on the change of particle size distribution after crushing according to the difference of crushability (HGI)

A coal sample of A, B, and C, having a particle size of 5 mm to 20 mm, was prepared. A was coking coal, B was high volatile tin, and C was semi-anthracite. And crushed until the particle size of the total of the A-phase, B-phase and C-phase was less than 5 mm using a crusher. The particle size distribution was measured by classifying A, B and C. The measured particle size distribution is shown in Table 1 below.

As shown in Table 1, in the HGI of each coal, A and C were 80 to 90 and B was 50 to 60. If the HGI value is large, it means that the crushing is good, and if the HGI value is small, it means that the crushing is bad. Therefore, it can be seen that A and C are crushed more easily than B.

Table 2 shows the particle size distribution of each coal according to the HGI difference. As shown in Table 2, the A and C carbons having a high HGI value had a relatively low coarse particle size ratio of 1 to 5 mm as compared with B having a low HGI value. On the other hand, the particle size ratios of particles A and C were 0.25 mm or less compared with those of particle B, respectively. Therefore, when A, B, and C are mixed together and crushed, A and C are likely to be crushed and B is likely to be crushed. Therefore, the particle size of A and C is relatively small while the particle size of B is relatively large. As described above, when the particle size distribution characteristics of the pulverized powder are not uniform, optimal particle size distribution characteristics can not be realized, so that the cold quality and the hot quality of the briquette are lowered. Further, in the case of crushing after mixing the A to C carbons, it is difficult to control the overall particle size.

In the particle size distribution  Following Cold quality  And Hot quality  Evaluation experiment

A, B, and C were prepared. The upper limit of maximum grain size of coal was classified into 5mm, 3mm and 1mm. Each coal, binder and curing agent was mixed in an appropriate ratio, and then pressed at room temperature using a roll press molding machine to produce pellet-shaped molded coal having a diameter of 51 mm, a width of 37 mm and a thickness of 24 mm. The volume of the briquette was 25 cm < ^{3 &} gt ;, and the compressive strength of the briquette was calculated according to the following equation (1).

[Equation 1]

Compressive strength (kgf) = compressive strength by compressive strength measuring instrument (average of 10 measurements)

Table 3 shows the compressive strength of the briquette according to the particle size distribution described above. As shown in Table 3, Coal A to Coal C showed the highest compressive strength when the maximum upper limit particle size was 3 mm. When the pressure is applied to the layered coal, cracks due to pressure are generated. Therefore, it is assumed that the larger the particle size, the larger the uniformity, and the compressive strength of the briquette is lowered.

On the other hand, HGI of B coal was lower than HGI of coal A and C, and the ratio of coarse coal was high, and coarse coal had a great influence on the compressive strength. In addition, the arithmetic average particle size of the B-particles calculated by the following formula (2) was much larger than the arithmetic average particle size of the A-shells.

&Quot; (2) "

Average weight (mm) = (3-5mm particle weight ratio ㅧ 4mm) + (1-3mm particle weight ratio × 2mm) + (1mm or less particle weight ratio × 0.5mm) / 100

As shown in Table 4 below, the specific gravity of the briquettes made of B is lower than the specific gravity of the briquettes made of A and C. Therefore, the compressive strength of B shot was also low. Considering the above points, when the A to C carbons are mixed and crushed, the compressive strength of the briquette decreases because the particle size after B crushing becomes relatively large. Therefore, it was found that when the A-to-C coal is separately separated and crushed, and then mixed together to produce the molded coal, the compression strength of the molded coal can be improved.

Type of coal High-grade Briquette 촤  Experiment of influence on strength

The briquettes prepared as described above were completely dried for 24 hours. The briquettes were placed in a round reaction furnace in an inert atmosphere at 1000 캜 and rotated at 10 rpm for 60 minutes. In a round reactor, a drum having a particle size of 10 mm or more was placed in an I drum drum and rotated at 600 rpm for 30 minutes at 20 rpm. Then, the ratio of the coarse grain of 10 mm or more was set as the grain strength according to the following equation (3).

&Quot; (3) "

촤 Strength (%) = ((I drum weight of 10 mm or more after measuring strength of drum (g) / (weight of drum of grain size of 10 mm or more before measuring drum strength) × 100

Table 5 shows the strength of the steel according to the difference in the upper and lower grain sizes. As shown in Table 5, unlike the above-mentioned compressive strength, the strength of the cords was better in the case of the larger maximum upper limit particle size in the case of A and B, but the smaller the upper limit of the C size was, the better.

As a result of the above-mentioned experiment, the compression strength indicating the cold quality of the briquette and the bending strength indicating the hot quality of the briquette were different according to the type of coal and the grain size. Therefore, in order to produce briquette having good characteristics in both the compressive strength and the bending strength of the briquette, it is desirable to separate and crush the various types of coals in consideration of the characteristics inherent to coal such as HGI and particle shape. To support this, another experiment was conducted as follows.

Experiment according to process classification

Experimental Example 1

A, B, and C charcoal were separated from each coal ash, and then crushed, followed by drying to produce a molded coal. In other words, A, B, and C were separated and crushed to take into consideration the characteristics of coal, and crushed A, B, and C were mixed and then dried in a batch to produce a blast furnace. A, B, and C were mixed with each other at blending ratios of 40 wt%, 30 wt%, and 30 wt%, respectively. The compressive strength and tensile strength of the briquette were measured.

Comparative Example 1

Coals identical to those used in Experimental Example 1 were mixed together, dried, and then crushed together. The remaining experimental procedure was the same as Experimental Example 1 described above.

Table 6 shows the measurement results of the compressive strength and the tensile strength of the briquettes prepared according to Experimental Example 1 and Comparative Example 1. As shown in Table 6, the compressive strength of Experimental Example 1 was increased by about 8.8% and the maximum strength was increased by about 5.4% as compared with Comparative Example 1. Therefore, it was found that both the cold quality and the hot quality of the briquette can be improved by using the separation and crushing process of the coal type in Experimental Example 1, rather than the batch type crushing process of Comparative Example 1.

Briquette  Moisture Deviation Experiment

The moisture content of the mixed coals used in the production of the briquettes of Experimental Example 1 and Comparative Example 1 was measured 20 times and their standard deviations were calculated and compared. Table 7 shows the moisture standard deviations of the mixed coals of Experimental Example 1 and Comparative Example 1 in comparison with each other.

As shown in Table 7, the moisture standard deviation was 0.43 in Comparative Example 1, but 0.30 in Experimental Example 1, which was lower than this. This is because, when the coal is first dried before the crushing of the coal as in the process of Comparative Example 1, the particle size of the coal introduced into the dryer is wide to 0 to 50 mm, and the drying characteristics are different according to the particle size difference under the same drying conditions. However, as in Experimental Example 1, when the coal is dried after the coal is crushed, the particle size of the coal becomes as small as 0 to 5 mm, so that the moisture deviation of the mixed carbon can be improved. Therefore, the amount of water contained in the mixed coal was uniformly controlled, and thus the molded coal having excellent cold quality and hot quality could be produced.

It will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the following claims.

10. Coal Storage
20. Crusher
40. Binder storage tank
50. Hardener reservoir
60. Mixer
70. Molding machine
85. Crusher
90. Dryer
92. Mixed carbon storage tank
94. Recovery tank
100. Blow molding machine
200, 300. Molten iron manufacturing equipment
210. Melting-gasification furnace
220. Packed bed type reduction furnace
230. Tungus
310. A fluidized-bed reduction reactor
320. Reduction iron compression unit
330. Compressed-reduced iron storage tank
805. Particle size selector
2101. Dome

Claims (12)

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 portion of the melter-gasifying furnace to be rapidly heated,
Providing coal of a plurality of types of coal,
Storing each of the plurality of coal species individually,
Individually crushing the coal of the plurality of seeds to provide a pulverization,
Mixing the powder, the hardener and the binder to provide a mixture, and
Molding the mixture to provide a blast furnace
Wherein the method comprises the steps of: The method according to claim 1,
And drying the pulverized coal together. 3. The method of claim 2,
Wherein the water standard deviation of the pulverized coal is 0.3 or less. The method according to claim 1,
Wherein the coal of the plurality of types of seeds is mixed with coal of the seeds having a difference of HGI (Hard Grove Grindability Index) of 10 or less among the coal of the plurality of seeds. 5. The method of claim 4,
Wherein the difference of the HGI index among the coal of the plurality of seed burdens is 5 or less. The method according to claim 1,
Wherein providing the mixture comprises:
Uniformly mixing the pulverized coal, and
Providing the binder and the curing agent to the homogeneously mixed powder and mixing them together
Wherein the method comprises the steps of: The method according to claim 1,
In the step of providing the pulverized coal, the particle size of the pulverized coal is larger than 0 and not larger than 5 mm. 8. The method of claim 7,
And the particle size of the pulverized coal is 1 mm to 3 mm. The method according to claim 1,
Wherein the coal of the plurality of types of coal includes a first coal and a second coal, and the crushing time of the first coal is different from the crushing time of the second coal. 10. The method of claim 9,
Wherein the crushing time of the first coal is longer than the crushing time of the second coal and the cohesion of the first coal is lower than the cohesion of the second coal. A plurality of coal reservoirs for individually storing coal of a plurality of types of coal,
A plurality of shredders connected to each of the plurality of coal storage tanks, each shredding coal of the plurality of seedlings individually to provide pulverized coal,
A binder storage tank in which the binder is stored,
A curing agent storage tank in which a curing agent is stored,
A mixer for providing a mixture by mixing the coal powder separately provided from each of the plurality of crushers, the binder provided from the binder reservoir, and the hardener provided from the hardener reservoir, and
And a molding machine for molding the mixture by receiving the mixture from the mixer
And a molding machine. 12. The method of claim 11,
And a dryer connected directly to the plurality of crushers to dry the pulverized coal together.

Images