WO2014104624A1

WO2014104624A1 - Coal briquette manufacturing method and coal briquette manufacturing apparatus

Info

Publication number: WO2014104624A1
Application number: PCT/KR2013/011550
Authority: WO
Inventors: 손창일; 허남환; 류진호; 이상호
Original assignee: 주식회사 포스코
Priority date: 2012-12-26
Filing date: 2013-12-12
Publication date: 2014-07-03
Also published as: US20150344800A1; EP2944681A1; CN104884587A; KR101405478B1; EP2944681A4; CN104884587B

Abstract

Provided are a coal briquette manufacturing method, which separately crushes coals by coal type so as to achieve excellent cold strength and hot strength, and a coal briquette manufacturing apparatus. The coal briquette manufacturing method is applied for insertion into a dome portion of a melting gas furnace so as to rapid heat in an ingot iron manufacturing device including: i) the melting gas furnace into which reduced iron is inserted; and ii) a reducing furnace that is connected to the melting gas furnace and provides the reduced iron. The coal briquette manufacturing method includes the steps of: i) providing a plurality of types of coals; ii) individually storing the respective pieces of the plurality of types of coals; iii) providing powdered coal by individually crushing each one of the plurality of types of coals; iv) providing a mixture by mixing the powdered coal, a curing agent, and a binder; and v) providing a coal briquette by molding the mixture.

Description

Briquette production method and briquette production device

The present invention relates to a method for producing coal briquettes and an apparatus for producing coal briquettes. More specifically, the present invention relates to a method for producing coal briquettes and an apparatus for producing coal briquettes, which can separate and crush coal for each type of coal to implement excellent cold strength and hot strength.

In the molten iron reduction method, iron ore is used as a reducing furnace and a molten gasifier for melting the reduced iron ore. When iron ore is melted in a melt gasifier, coal briquettes are charged into a melt gasifier as a heat source for melting iron ore. Here, the reduced iron is melted in the molten gasifier, converted to molten iron and slag and then discharged to the outside. The coal briquettes charged into the melt gasifier form a coal filling layer. Oxygen is blown through the tuyere installed in the melt gasifier and then burns the coal packed bed to produce combustion gas. Combustion gas is converted into hot reducing gas while rising through the coal-filled bed. The high temperature reducing gas is discharged to the outside of the melt gasification furnace and supplied to the reduction furnace as reducing gas.

In the case of using the coal briquettes, it is necessary to increase the production of molten iron and to reduce the fuel cost to streamline the molten iron manufacturing process. To this end, the amount of differentiation of the coal briquettes in the melt gasifier has to be reduced to maintain the coal briquettes in the melt gasifier. In this case, it is possible to increase the reaction efficiency and heat transfer efficiency between the respective materials by ensuring the air permeability and liquid permeability for the smooth passage of gas and liquid in the melt gasifier. In addition, due to the differentiation, it is possible to reduce the amount of fine powder that can not be used efficiently in the manufacture of molten iron. There is a limit in reducing the amount of fine powder generated by blending various coals.

The present invention is to provide a method for producing coal briquettes that can separate and crush coal for each type of coal to implement excellent cold strength and hot strength. In addition, the present invention is to provide an apparatus for manufacturing coal briquettes capable of realizing excellent cold strength and hot strength by separating and crushing coal for each type of coal.

Method for producing coal briquettes according to an embodiment of the present invention, molten gasification furnace in the molten iron manufacturing apparatus comprising: i) a molten gas furnace in which reduced iron is charged, and ii) a reducing furnace connected to the molten gasifier, providing a reduced iron It is loaded into the dome of and applied to rapid heating. The method for producing coal briquettes includes: i) providing coals of a plurality of coal species, ii) storing coals of a plurality of coal species individually, and iii) separately crushing coals of the coal coals respectively to provide powdered coal. Steps, iv) mixing the coal powder, the curing agent and the binder to provide a mixture, and v) molding the mixture to provide coal briquettes.

Method for producing coal briquettes according to an embodiment of the present invention may further comprise the step of drying the coal dust together. The standard deviation of moisture in the powdered coal may be 0.3 or less. In the providing of the coals of the plurality of coal species, coals of the coal species having a difference in Hardwood Grindability Index (HGI) of 10 or less coals among the coals of the coal coales may be provided together. The difference in HGI index among the coals of the plurality of coal species may be 5 or less.

Providing the mixture may include i) uniformly mixing the powdered coal, and ii) providing a binder and a hardener to the uniformly mixed powdered coal and mixing them together. In the step of providing powdered coal, the particle size of the powdered coal may be greater than 0 and 5 mm or less. The particle size of the powdered coal may be 1 mm to 3 mm.

In the providing coal dust, the coals of the plurality of coal species include 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 may be longer than the crushing time of the second coal, and the cohesiveness of the first coal may be lower than that of the second coal.

Apparatus for manufacturing coal briquettes according to an embodiment of the present invention, i) a plurality of coal storage tanks for storing coals of a plurality of coal species, ii) is connected to each of the plurality of coal storage tanks pulverized coal of a plurality of coal species by coal dust A plurality of shredders to provide, iii) a binder reservoir in which the binder is stored, iv) a curing agent reservoir in which the curing agent is stored, v) a coal provided from the plurality of shredders, a binder provided in the binder reservoir, and a curing agent provided in the curing agent reservoir, A mixer for providing the mixture, and vi) a molding machine for receiving the mixture from the mixer and molding the mixture. Apparatus for manufacturing coal briquettes according to an embodiment of the present invention may further include a dryer connected directly to the plurality of crushers to dry the powdered coal together.

Since coal is manufactured by separating and crushing coal by coal type and drying the coal briquettes, it is possible to improve cold strength and hot strength of the coal briquettes manufactured. Therefore, it is possible to improve the operation efficiency and fuel cost in the molten iron manufacturing process by increasing the size and strength of the char obtained by the rapid coal decomposition of the coal briquettes in the molten gasifier. In addition, inexpensive coal having low crushability can be used as a raw material of coal briquettes, and the amount of binder used can also be reduced.

1 is a schematic flowchart of a method of manufacturing coal briquettes according to an exemplary embodiment of the present invention.

2 is a schematic view of the coal briquette manufacturing apparatus according to an embodiment of the present invention.

3 is a schematic diagram of a molten iron manufacturing apparatus connected to the coal briquette manufacturing apparatus of FIG. 2.

4 is a schematic view of another molten iron manufacturing apparatus connected to the coal briquette manufacturing apparatus of FIG.

Terms such as first, second, and third are used to describe various parts, components, regions, layers, and / or sections, but are not limited to these. These terms are only used to distinguish one part, component, region, layer or section from another part, component, region, layer or section. Accordingly, the first portion, component, region, layer or section described below may be referred to as the second portion, component, region, layer or section without departing from the scope of the invention.

The terminology used herein is for reference only to specific embodiments and is not intended to limit the invention. As used herein, the singular forms “a,” “an,” and “the” include plural forms as well, unless the phrases clearly indicate the opposite. As used herein, the meaning of "comprising" embodies a particular characteristic, region, integer, step, operation, element and / or component, and the presence of other characteristics, region, integer, step, operation, element and / or component It does not exclude the addition.

Unless defined otherwise, all terms including technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. Commonly defined terms used are additionally interpreted to have a meaning consistent with the related technical literature and the presently disclosed contents, and are not interpreted in an ideal or very formal sense unless defined.

The term "HGI" used hereinafter is used as a measure of the resistance of coal to fracture as a Hardgrove Grindability Index. For example, HGI puts 50 g of a uniformly sized prepared coal sample into a grinding unit, treats the unit at standard revolutions at the specified pressure, and the steel balls in the unit break up the coal sample, sort the coal particulates, and then Record the amount of coal below and convert it to an HGI value.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

Figure 1 schematically shows a flow chart of a method for producing coal briquettes according to an embodiment of the present invention. The manufacturing method of the coal briquettes of FIG. 1 is merely for illustrating the present invention, and the present invention is not limited thereto. Therefore, the method of manufacturing coal briquettes may be variously modified.

As shown in FIG. 1, the method for manufacturing coal briquettes includes providing coals of a plurality of coal species (S10), storing coals of a plurality of coal species individually (S20), and coals of a plurality of coal species, respectively. Separately crushing (S30), mixing the crushed coal, the curing agent and a binder to provide a mixture (S40), and molding the mixture to provide a coal briquettes (S50). In addition, if necessary, the method of manufacturing coal briquettes may further include other steps.

Firstly, in step S10, coals of a plurality of coal species are provided. As coal required for producing the coal briquettes, for example, anthracite coal, coking coal, semi-anthracite coal, fine coal, and the like can be used. Uncoking coal may contain large amounts of volatiles. On the other hand, although not illustrated in Figure 1, in order to improve the quality of molten iron can be mixed with coal for quality control. Here, coal having a reflectance of a predetermined value or more may be used as the coal for quality control.

The particle size distribution range of coal of a plurality of coal species is larger than 0 and less than 50mm, which is very wide. On the other hand, coal has a different Hardwood Grindability Index (HGI) depending on the degree of carbonization. Low-carbon lignite or sub-bituminous coal has a low HGI, bituminous coal has a high HGI, and anthracite with the highest carbonity has a low HGI.

In operation S20, coals of a plurality of coal species are stored separately. When the coals of a plurality of coal species are mixed and stored together, the particle size variation and the moisture variation adversely affect the quality of the coal briquettes when the coal briquettes are manufactured in a subsequent process. Therefore, coals of a plurality of coal species are stored separately from each other.

Next, in step S30, the coals of the plurality of coal species are separately broken to provide powdered coal. That is, the coals of the plurality of coal species are separately crushed. For example, the average particle size of coals of a plurality of coal species may be adjusted to 5 mm or less to be crushed. When the average particle size of the coals of the plurality of coal species is larger than 5 mm, it is difficult to uniformly mix the coals of the plurality of coal species in a subsequent process, so that the quality of the coal briquettes may be degraded. Therefore, the average particle size of coals of the plurality of coal species is adjusted to the above-mentioned range. Preferably, the average particle size of the coals can be controlled to 1 mm to 3 mm.

Coals of a plurality of coal species may have mutually different HGI. For example, the difference in HGI of the coals of the plurality of coal species may be 10 or less. If the difference in HGI is too large, it is not suitable as a coal raw material for producing coal briquettes. Therefore, the difference of HGI is adjusted to the above-mentioned range. Preferably, the difference in HGI may be 5 or less.

On the other hand, since the coals of the plurality of coal species having mutually different HGI are separately crushed, the crushing times of the coals of the plurality of coal species may be different from each other. In other words, coals with low HGI do not break well into fine particles, which leads to longer crushing times. Conversely, coals with high HGI are crushed well, which reduces the crushing time. On the other hand, since the coal with high caking property is crushed well, the higher the caking property, the longer the crushing time.

Conventionally, coals of various coal species are dried together and crushed together in a crusher. In this case, the particle size of the coal changes according to the difference in the strength of the coal, so that the particle size distribution of the coal collected coal is very wide. Therefore, not only the water deviation of the coal mixture is large, but also the particle size management is difficult due to the wide particle size distribution due to the different HGI, and it is difficult to control the particle size when the mixing ratio of coal by coal type is changed. As a result, the hot and cold quality of the coal briquettes produced in subsequent processes may be adversely affected. On the other hand, in one embodiment of the present invention, since the coal of each coal species is separately crushed and mixed together, the particle size distribution is narrowed. Here, the crushing of coal is carried out by changing the capacity of the crusher, the crushing conditions and the crushing speed. As a result, not only the water variation of the mixed coal is small, but also the mixed coal has a uniform particle size, so that coal briquettes having excellent characteristics can be produced.

On the other hand, although not shown in Figure 1, it is possible to dry the mixed coal in which the powdered pulverized coal together. In this case, the powdered coal having a constant particle size is dried, so that the variation in moisture of the mixed coal can be minimized. Therefore, since the moisture content and the water variation of the mixed coal can be controlled appropriately, the quality of the coal briquettes can be further improved. For example, the water standard deviation of the coal blended coal powder can be adjusted to 0.3 or less. If the water standard deviation of the mixed coal is too large, the amount of water contained in the mixed coal is not constant, deteriorating the quality of the coal briquettes.

Conventionally, after drying coal, the water content of coal was automatically controlled to be a target value. In this case, many parameters, such as coal drying amount, drying temperature of coal dryer, air volume, and moisture content of coal before drying, were required for automatic control. In addition, when measuring moisture, in order to raise the accuracy of the measured value, the quantity of the sample for moisture measurement must be large, and the sample must be taken uniformly. This makes mechanical sampling and drying for coal moisture automatic measurement increasingly difficult. Therefore, it becomes difficult to cope with the change in the moisture of the coal before drying the coal, so that automatic moisture control becomes impossible. In contrast, in one embodiment of the present invention, the coal is dried after crushing the coal to uniform its particle size, thereby simplifying the drying process of coal.

Next, in step S40, the crushed coals, the hardener and the binder are mixed to provide a mixture. Here, the crushed coals, graphite, curing agent and binder may be mixed in any order or a specific raw material may be mixed first. For example, the crushed coal and the binder may be mixed first and then the curing agent may be mixed. Alternatively, the crushed coals and the curing agent may be mixed first, and then the curing agent may be mixed.

As a hardener, quicklime, slaked lime, metal oxide, fly ash, clay, surfactant, cationic resin, fastener, fiber, phosphoric acid, sludge, waste plastic, waste lubricant, waste toner, graphite or activated carbon can be used. . In addition, molasses, starch, sugar, polymer resin, pitch, tar, bitumen, oil, cement, asphalt or water glass may be used as the binder. For example, the cold strength of the coal briquettes can be greatly improved by the use of molasses as a binder and quicklime as a hardener, by gluconate bonding in the production of coal briquettes.

On the other hand, in step S40 it is possible to provide a mixture by first mixing the powdered coal uniformly and then providing a binder and a curing agent. That is, since the coal powder includes various coal species, the quality of coal briquettes may be deteriorated when the coal powder is not uniformly mixed. Therefore, before supplying a binder and a hardening | curing agent to powdered coal, powdered coal is mixed uniformly first.

Finally, in step S50, the mixture is molded to provide coal briquettes. For example, the coal briquettes may be manufactured by continuously compressing the mixture using a molding machine including a pair of forming rolls.

2 schematically shows a coal briquette manufacturing apparatus 100 according to an embodiment of the present invention. Apparatus 100 for manufacturing coal briquettes in FIG. 2 is merely for illustrating the present invention, and the present invention is not limited thereto. Therefore, the structure of the coal briquette manufacturing apparatus 100 may be variously modified.

As shown in FIG. 2, the coal briquette manufacturing apparatus 100 includes a coal storage tank 10, a crusher 20, a binder storage tank 40, a hardener storage tank 50, a mixer 60, and a molding machine 70. . In addition, the coal briquette manufacturing apparatus 100 further includes a dryer 90, a mixed coal storage tank 92, a recovered coal storage tank 94, and a particle size separator 805. If necessary, the coal briquette manufacturing apparatus 100 may further include other devices. The specific structure and operation method of each device included in the coal briquette manufacturing apparatus 100 of FIG. 2 may be easily understood by those skilled in the art to which the present invention pertains, and thus detailed description thereof will be omitted.

The plurality of coal storage tanks 10 each store a plurality of coal species. For example, in order to improve the quality of coal briquettes in addition to coal used as a raw material of coal briquettes, quality control coal may be used. Therefore, in order to mix an appropriate amount of quality control coal according to the amount of coal used as a raw material, a plurality of coal storage tanks 10 are separately installed.

The plurality of shredders 20 are each connected to the plurality of coal reservoirs 10, respectively. The plurality of crushers 20 receives coal of different coal types from each of the coal storage tanks 10 and crushes them. For example, coal may be crushed to provide powdered coal having a particle size of 8 mm or less. Although not shown in FIG. 2, the pulverized pulverized coal may be directly provided to the mixer 60. In addition, the pulverized pulverized coal may be supplied to the mixer 60 after drying.

The dryer 90 dries together the pulverized pulverized powder in each crusher 20. Therefore, in the dryer 90, the powdered coals of the plurality of coal species may be mixed and dried together and then supplied to the mixer 60.

As shown in FIG. 2, the binder is stored in the binder reservoir 40. The binder combines the pulverized coals of the plurality of coal species into a state suitable for producing coal 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 hardener can be combined with coal and binder to cure the coal briquettes to optimize their strength. The hardener reservoir 50 is connected with the mixer 60 to provide the hardener to the mixer 60.

The mixer 60 provides a mixture for producing coal briquettes by mixing coal dust, a binder, a curing agent, and the like with each other. Before being fed to the mixer 60, a plurality of coal species are stored together in the coal mixture tank 92, premixed, and again mixed uniformly with each other in the mixer 60. Since the powdered coals include a plurality of coal species, the mixer 60 is driven and mixed uniformly before the binder and the hardener are introduced into the mixer 60. When the binder and the curing agent are directly added to the mixer 60, the coals of the plurality of coal species may not be uniformly mixed, and thus the quality of the coal briquettes may be degraded. Therefore, the powdered coals of the plurality of coal species are first mixed in the mixer 60.

As shown in FIG. 2, the molding machine 70 includes a pair of rolls that rotate in opposite directions. Coal briquettes are produced by feeding a mixture between a pair of rolls to compress the mixture by a pair of rolls. Meanwhile, the manufactured coal briquettes are classified again through the particle size separator 805 to store the powdered coal in the recovered coal storage tank 94. The powdered coal stored in the recovered coal storage tank 94 may be supplied back to the mixer 60 to be used as a raw material of coal briquettes. As a result, the utilization efficiency of powdered coal can be improved.

FIG. 3 schematically illustrates a molten iron manufacturing apparatus 200 connected to the coal briquette manufacturing apparatus 100 of FIG. 2 using the coal briquettes manufactured by the coal briquette manufacturing apparatus 100. The structure of the apparatus for manufacturing molten iron 200 of FIG. 3 is merely for illustrating the present invention, and the present invention is not limited thereto. Therefore, the apparatus for manufacturing molten iron 200 of FIG. 3 may be modified in various forms.

The apparatus for manufacturing molten iron 200 of FIG. 3 includes a melt gasifier 210 and a reduction furnace 220. In addition, the apparatus for manufacturing molten iron 200 may include other devices as necessary. Iron ore is charged into the reduction furnace 220 to be reduced. Iron ore charged in the reduction furnace 220 is made of reduced iron while passing through the reduction furnace 220 after being pre-dried. Reduction furnace 220 is a packed-bed reduction reactor, receives a reducing gas from the melt gasifier 210 to form a packed layer therein.

Since the coal briquettes manufactured by the coal briquette manufacturing apparatus 100 of FIG. 2 are charged into the melt gasifier 210 of FIG. 3, a coal filling layer is formed inside the melt gasifier 210. The dome part 2101 is formed at an upper portion of the melt gasifier 210. A high temperature reducing gas is present in the dome portion 2101 formed in a wider space than other portions of the melt gasifier 210. The coal briquettes are charged into the dome portion 2101 of the melt gasifier 210 and then rapidly heated to fall to the bottom of the melt gas furnace 210. The char generated by the pyrolysis reaction of the coal briquettes moves to the lower portion of the melt gasifier 210 and exothermicly reacts with oxygen supplied through the tuyere 230. As a result, the coal briquettes can be used as a heat source for maintaining the molten gasifier 210 at a high temperature. On the other hand, 촤 provides breathability, so that a large amount of gas generated in the lower portion of the melt gasifier 210 and the reduced iron supplied from the reducing furnace 220 may pass through the coal-filled layer in the melt gasifier 210 more easily and uniformly. Can be.

In addition to the coal briquettes described above, a bulk coal material or coke may be charged into the melt gasifier 210 as necessary. The outer wall of the melt gasifier 210 is provided with a tuyere 230 to blow oxygen. Oxygen is blown into the coal packed bed to form a combustion zone. The coal briquettes may be burned in a combustion zone to generate reducing gas.

FIG. 4 schematically illustrates another molten iron manufacturing apparatus 300 connected to the coal briquette manufacturing apparatus 100 of FIG. 2 and using the coal briquettes manufactured by the coal briquette manufacturing apparatus 100. The structure of the apparatus for manufacturing molten iron 300 of FIG. 4 is merely for illustrating the present invention, and the present invention is not limited thereto. Therefore, the apparatus for manufacturing molten iron 300 of FIG. 4 may be modified in various forms. Since the structure of the apparatus for manufacturing molten iron 300 of FIG. 4 is similar to that of the apparatus for manufacturing molten iron 200 of FIG. 3, the same reference numerals are used for the same parts, and a detailed description thereof will be omitted.

As shown in FIG. 4, the apparatus for manufacturing molten iron 100 includes a molten gasifier 210, a fluidized bed reduction furnace 310, a reduced iron compression device 320, and a compressed reduced iron storage tank 330. Here, the compressed reduced iron storage tank 330 may be omitted.

The produced coal briquettes are charged into a melt gasifier 210. Here, the coal briquettes generate a reducing gas in the molten gasifier 210 and the generated reducing gas is supplied to the fluidized bed reducing furnace 310. The iron ore is supplied to the fluidized-bed reduction furnace 310 and is made of reduced iron while flowing by the reducing gas supplied from the melt gasifier 210 to the fluidized-bed reduction furnace 310. The reduced iron is compressed by the reduced iron compression device 320 and then stored in the reduced reduced iron storage tank (50). Compressed reduced iron is supplied to the melt gasifier 210 from the compressed reduced iron storage tank 330 is melted in the melt gasifier (210). Since the coal briquettes are charged into the melt gasifier 210 and changed into air permeable, a large amount of gas and compressed reduced iron generated in the lower portion of the melt gasifier 210 makes the coal filling layer in the melt gasifier 210 easier and more uniform. It can be passed through to produce high quality molten iron. On the other hand, oxygen is supplied through the tuyere 230 to burn the coal briquettes.

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

실험예Experimental Example

탄종별 파쇄성(HGI) 차이에 따른 파쇄후 입도분포변화 평가 실험Evaluation of Changes in Particle Size Distribution after Crushing according to Different Types of HGI

Coal samples of coal A, coal B and coal C having particle sizes of 5 mm to 20 mm were prepared. Coal A was coking coal, Coal B was unvolatile coal of high volatile matter, and Coal C was semi-anthracite coal. The crusher was crushed until the particle size of the total amount of A, B and C coals was 5 mm or less. The A, B and C coals were classified and the particle size distribution was measured. The measured particle size distribution is shown in Table 1 below.

Table 1

NO	Coal	HGI
One	A shot	80-90
2	B bullet	50-60
3	C shot	80-90

As shown in Table 1, in the HGI of each coal, the coal A and coal C were 80 to 90, and the coal B was 50 to 60. If the HGI value is large, it means that crushing is good. If the HGI value is small, it means that crushing is not good. Therefore, it was found that the coals A and C were more crushed than the coal B.

On the other hand, the particle size distribution of each coal according to the HGI difference is shown in Table 2 below. As shown in Table 2, A and C coals having a high HGI value had a relatively low coarse particle size ratio of 1 to 5 mm compared to B coal having a low HGI value. On the other hand, A and C coals had a relatively high particle size fraction of 0.25 mm or less compared to B coal. Therefore, in the case of shredding after mixing A, B and C coal together, the A and C coals are likely to be over-crushed, and the B-tans are more likely to be uncrushed. Therefore, the particle size of the A and C coals is relatively small while the particle size of the B coal is relatively high. As described above, when the particle size distribution characteristic of the pulverized coal is not uniform, the optimum particle size distribution characteristic cannot be realized, and thus the cold quality and the hot quality of the coal briquettes are deteriorated. In addition, in the case of crushing after mixing A to C coal, the overall particle size was difficult to control.

TABLE 2

NO	Coal	Coal particle size distribution
NO	Coal	-0.25mm	0.25 ~ 0.5mm	0.5-1mm	1-5mm
One	A shot	30.6%	14.0%	18.2%	37.2%
2	B bullet	12.1%	11.6%	22.3%	54.0%
3	C shot	29.2%	14.4%	17.2%	39.2%

입도분포에 따른 냉간품질 및 열간품질 평가 실험Evaluation of cold quality and hot quality according to particle size distribution

A, B and C bullets were prepared. The upper limit of coal particle size was divided into 5mm, 3mm and 1mm for each coal type. Each coal, binder, and curing agent were mixed at an appropriate ratio, and then pressurized at room temperature using a roll press molding machine to produce pillow-shaped coal briquettes having a diameter of 51 mm, a width of 37 mm, and a thickness of 24 mm. The volume of the coal briquettes was 25 cm ^3, and the compressive strength of the coal briquettes was calculated according to Equation 1 below.

[Equation 1]

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

Table 3 shows the compressive strength of the coal briquettes 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 particle size was 3 mm. When pressure is applied to the coal having a layered structure, cracking due to pressure occurs, and it is estimated that the larger the particle size, the larger the uniformity and the compressive strength of the coal briquettes is lowered.

TABLE 3

NO	Coal	Maximum upper limit of coal
NO	Coal	-5mm	-3mm	-1mm
One	A shot	43.2kgf	49.3kgf	48.2kgf
2	B bullet	43.0kgf	44.2kgf	44.1kgf
3	C shot	44.1kgf	47.2kgf	46.5kgf

On the other hand, the HGI of the coal B is lower than that of the coal A and the coal C, so that the ratio of coarse coal is high, and the coarse coal has a great influence on the compressive strength. In addition, the arithmetic mean particle size of bullet B, which was calculated by Equation 2 below, was much larger than that of A bullet.

[Equation 2]

Arithmetic mean particle size (mm) = (3-5mm particle size ratio ㅧ 4mm) + (1-3mm particle size ratio x 2mm) + (1mm particle size ratio x 0.5mm) / 100

And, as shown in Table 4 below, the specific gravity of the coal briquettes made of coal B was found to be lower than the specific gravity of coal briquettes made of coal A and coal. Therefore, the compressive strength of the B bullets was also low due to this. In consideration of the foregoing, when the A-to-C coal is mixed and crushed, the particle size after crushing the B coal is relatively large, so that the compressive strength of the coal briquettes is lowered. Therefore, it was found that the coal strength of the coal briquettes may be improved when A to C coal is separately separated, crushed, and mixed together to produce coal briquettes.

Table 4

NO	Coal	Particle size distribution	+ 3mm (%) after shredding	Arithmetic mean (mm)	Coal briquette specific gravity (g / cm ³ )
One	A shot	-5mm	2.7	0.98	1.223
2		-3mm	0.0	0.58	1.238
3		-1mm	0.0	0.31	1.224
4	B bullet	-5mm	5.3	1.36	1.211
5		-3mm	0.0	0.75	1.210
6		-1mm	0.0	0.40	1.205
7	C shot	-5mm	4.1	1.19	1.256
8		-3mm	0.0	0.72	1.256
9		-1mm	0.0	0.37	1.257

탄종별 상한입도의 성형탄의 촤의 강도에 대한 영향 실험Influence test on the strength of char of coal briquettes with upper particle size

The coal briquettes prepared as described above were completely dried for 24 hours. The coal briquettes were put into a circular reactor in an inert atmosphere at 1000 ° C. and rotated at 10 rpm for 60 minutes. Among them, the particle size of more than 10mm was put into the I drum strength device and rotated at 600 rpm for 30 minutes at 20 rpm. And according to the following equation (3) the ratio of coarse coarse grains of 10mm or more was set to the strength of the.

[Equation 3]

촤 Strength (%) = ((촤 Weight (g) of particle size of 10 mm or more after I drum strength measurement / (촤 Weight (g) of particle size of 10 mm or more before I drum strength measurement)) × 100

The strength of 촤 according to the upper limit of particle size by type of coal is shown in Table 5 below. As shown in Table 5, in contrast to the above-described compressive strength, the strength of the char was better in the A and B bullets, but the larger the maximum upper particle size, the better the smaller the maximum carbon particle size.

Table 5

NO	Coal	Maximum upper limit of coal
NO	Coal	-5mm	-3mm	-1mm
One	A shot	46.8%	42.4%	41.0%
2	B bullet	65.6%	64.7%	59.0%
3	C shot	49.1%	51.5%	54.6%

As a result of the above experiment, the compressive strength representing the cold quality of the coal briquettes and the shear strength representing the hot quality of the coal briquettes showed different characteristics by coal type and particle size. Therefore, in order to manufacture coal briquettes having good characteristics in both the compressive strength and the char strength of the coal briquettes, it was judged that it is desirable to separate and crush various kinds of coals in consideration of the characteristics of coal such as HGI and particle shape. In order to support this, another experiment was conducted as follows.

공정 구분에 따른 실험Experiment by process classification

실험예 1Experimental Example 1

Coal coal was prepared by separating and crushing coal A, coal B and coal C for each coal type. In other words, coal particles were considered by separating and crushing A, B, and C coals, and pulverized coals were prepared by mixing and crushing the crushed A, B, and C coals. A, B and C coals were mixed with each other at a blending ratio of 40 wt%, 30 wt% and 30 wt%, respectively. And the compressive strength and the crush strength of the coal briquettes were measured.

비교예 1Comparative Example 1

The same coals used in Experimental Example 1 were mixed together, dried, and then crushed together. The rest of the experiment was the same as in Experiment 1 described above.

Table 6 shows the measurement results of the compressive strength and the shear strength of the coal briquettes prepared according to Experimental Example 1 and Comparative Example 1. As shown in Table 6, Experimental Example 1, the compressive strength was increased by about 8.8%, and the maximum strength was increased by about 5.4% compared to Comparative Example 1. Therefore, it could be seen that the cold quality and the hot quality of the coal briquettes can be improved when the coal type separation crushing process of Experimental Example 1 is used rather than the batch type crushing process of Comparative Example 1.

Table 6

NO	Experimental Example	Compressive strength	Strength
One	Experimental Example 1	47.1kgf	54.6%
2	Comparative Example 1	43.3kgf	51.8%

성형탄의 수분 편차 실험Moisture Deviation Test of Coal Briquettes

The moisture content of the mixed coal used at the time of manufacture of the coal briquettes of Experimental Example 1 and Comparative Example 1 was measured 20 times, and the standard deviation was obtained and compared with each other. Table 7 compares the water standard deviation of the mixed carbons of Experimental Example 1 and Comparative Example 1 with each other.

As shown in Table 7, the moisture standard deviation was 0.43 in Comparative Example 1, but was lower than 0.30 in Experimental Example 1. This is because when the first drying before crushing the coal as in the process of Comparative Example 1, the particle size range of the coal flowing into the dryer is 0 to 50mm wide, so that the drying characteristics vary depending on the particle size difference even under the same drying conditions. However, when the coal is dried after crushing the coal as in Experimental Example 1, the particle size range of the coal is very small as 0 ~ 5mm, it is possible to improve the water variation of the mixed coal. Therefore, by controlling the amount of water contained in the mixed coal uniformly, the coal briquettes having excellent cold quality and hot quality could be manufactured.

TABLE 7

NO	Experimental Example	Moisture Standard Deviation
One	Experimental Example 1	0.30
2	Comparative Example 1	0.43

Although the present invention has been described above, it will be readily understood by those skilled in the art that various modifications and variations can be made without departing from the spirit and scope of the claims set out below.

[Description of the code]

10. Coal Reservoir

20. Crushers

40. Binder Storage Tank

50. Hardener Reservoir

60. Mixer

70. Molding Machine

85. Crushers

90. Dryer

92. Mixed coal reservoir

94. Recovery Coal Storage Tank

100. Coal briquette manufacturing apparatus

200, 300. molten iron manufacturing equipment

210. Melt Gasification Furnace

220. Packed Bed Type Reduction Furnace

230. Fenggu

310. Fluidized Bed Reduction Furnace

320. Reduced iron compression device

330. Compressed Reduced Iron Storage Tank

805. Granularity sorter

2101.The Dome

Claims

A molten gas furnace in which reduced iron is charged, and

A reducing furnace connected to the melt gasifier and providing the reduced iron

In the molten iron manufacturing apparatus comprising a charging method for manufacturing coal briquettes is applied to the dome of the molten gasifier to be rapidly heated,

Providing coals of the plurality of coal species,

Storing the coals of the plurality of coal species individually,

Separately crushing coals of the plurality of coal species to provide powdered coal,

Mixing the powdered coal, the curing agent, and the binder to provide a mixture, and

Molding the mixture to provide coal briquettes

Method of producing coal briquettes comprising a.
The method of claim 1,

Method for producing coal briquettes further comprising the step of drying the coal dust together.
The method of claim 2,

Moisture standard deviation of the coal dust is 0.3 or less method for producing coal briquettes.
The method of claim 1,

In the step of providing coals of the plurality of coal species, coal coal of coal species having a difference in Hardwood Grindability Index (HGI) of 10 or less coal among the coals of the plurality of coal species is provided with a mixture.
The method of claim 4, wherein

Method of producing coal briquettes of the coal of the plurality of coal species is the difference in HGI index of 5 or less.
The method of claim 1,

Providing the mixture,

Uniformly mixing the powdered coal, and

Providing a binder and a curing agent to the uniformly mixed powdered coal and mixing them together

Method of producing coal briquettes comprising a.
The method of claim 1,

In the step of providing the powdered coal, the particle size of the powdered coal is greater than 0 and 5mm or less manufacturing method of coal briquettes.
The method of claim 7, wherein

The particle size of the coal dust is 1mm to 3mm manufacturing method of coal briquettes.
The method of claim 1,

In the step of providing the coal coal, the coal of the plurality of coal species comprises a first coal and a second coal, the shredding time of the first coal is different from the shredding time of the second coal.
The method of claim 9,

The crushing time of the first coal is longer than the crushing time of the second coal, and the coking property of the first coal is lower than that of the second coal.
A plurality of coal reservoirs for storing coals of a plurality of coal species,

A plurality of crushers connected to each of the plurality of coal storage tanks to crush coals of the plurality of coal species to provide powdered coal,

A binder reservoir in which a binder is stored,

A hardener reservoir in which the hardener is stored,

A mixer for mixing the powdered coal provided from the plurality of crushers, the binder provided from the binder reservoir, and the curing agent provided from the curing agent reservoir to provide a mixture, and

A molding machine for receiving the mixture from the mixer and molding the mixture

Coal briquette manufacturing apparatus comprising a.
The method of claim 11,

The coal briquette manufacturing apparatus further comprises a dryer connected directly to the plurality of crushers to dry the powdered coal together.