WO2016140428A1

WO2016140428A1 - Coal briquette, method for manufacturing same, device for manufacturing same, ingot iron manufacturing method, and ingot iron manufacturing device

Info

Publication number: WO2016140428A1
Application number: PCT/KR2015/014010
Authority: WO
Inventors: 류진호; 이상호; 박우일; 박석인
Original assignee: 주식회사 포스코
Priority date: 2015-03-04
Filing date: 2015-12-21
Publication date: 2016-09-09
Also published as: CN107406782A; EP3266855A4; WO2016140428A8; EP3266855A1

Abstract

Provided are a coal briquette, a method for manufacturing the same, a device for manufacturing the same, an ingot iron manufacturing method, and an ingot iron manufacturing device. The coal briquette is inserted into a domed portion of a melting gas brazier of an ingot iron manufacturing device and is heated rapidly, the ingot iron manufacturing device comprising: i) a melting gas brazier, into which reduced iron is inserted; and ii) a reducing furnace, which is connected to the melting gas brazier, and which provides reduced iron. A coal briquette manufacturing method comprises the steps of: i) providing pulverized coal; ii) mixing the pulverized coal with a powder-type cellulose ether compound, thereby providing a mixture; iii) adding water to the mixture and mixing the same; and iv) providing a coal briquette by molding the mixture. In the step of providing a coal briquette, the amount of cellulose ether compound included in the coal briquette is 0.7wt% to 2.0wt%.

Description

Coal briquettes, the manufacturing method, a manufacturing apparatus, a molten iron manufacturing method, and a molten iron manufacturing apparatus

The present invention relates to coal briquettes, a production method thereof, a production apparatus, a molten iron production method, and a molten iron production apparatus. More specifically, the present invention relates to coal briquettes using a powdered cellulose ether compound as a binder, a production method thereof, a production apparatus, a molten iron production method, and a molten iron production apparatus.

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.

Coal briquettes are prepared by mixing pulverized coal and a binder. In order to use molten iron, it is necessary to manufacture coal briquettes having excellent cold strength and hot strength. Therefore, coal briquettes are manufactured using a binder having excellent viscosity such as molasses.

The present invention provides a coal briquette having excellent hot strength and cold strength by using a cellulose ether compound or the like as a binder. Moreover, the manufacturing method of the coal briquettes mentioned above is provided. And to provide a molten iron manufacturing method including the above-described method for producing coal briquettes.

Coal briquettes according to an embodiment of the present invention is charged into the dome portion of the molten gasifier in the molten iron manufacturing apparatus comprising a reducing gas which is i) a molten gasifier to which iron is charged, and ii) a molten gasifier, and providing a reduced iron. It is heated rapidly. The process for producing coal briquettes includes i) providing pulverized coal, ii) mixing the powdered cellulose ether compound with pulverized coal to provide a mixture, iii) adding water to the mixture and mixing the mixture, and iv) mixing the mixture. Shaping to provide coal briquettes. In the providing of the coal briquettes, the amount of the cellulose ether compound included in the coal briquettes is 0.7 wt% to 2.0 wt%.

More preferably, the amount of cellulose ether compound may be 0.8 wt% to 1.5 wt%. In the step of providing coal briquettes, the amount of water contained in the coal briquettes may be 5wt% to 15wt%. More preferably, the amount of water contained in the coal briquettes may be 7wt% to 12wt%.

The ratio of the amount of water contained in the coal briquettes to the amount of the cellulose ether compound contained in the coal briquettes may be 5 to 40. In addition, the ratio of the amount of water contained in the coal briquettes to the amount of the cellulose ether compound contained in the coal briquettes may be 7 to 20.

In providing the mixture, the average particle size of the cellulose ether compound may be 50 μm to 100 μm. More preferably, in the step of providing the mixture, the ratio of the average particle size of the pulverized coal to the average particle size of the cellulose ether compound may be 7 to 30. The ratio of the average particle size of the pulverized coal to the average particle size of the cellulose ether compound may be 10 to 20.

The mixing time in providing the mixture is less than the mixing time in adding water to the mixture and mixing, and the mixing time in providing the mixture to the mixing time in adding water to the mixture and mixing. The ratio of may be 2 to 5. The cellulose ether compound is at least 1 selected from the group consisting of methyl cellulose (MC), hydroxyethyl cellulose (HEC), hydroxypropyl cellulose (HPC), hydroxypropyl methyl cellulose (HPMC) and hydroxyethyl methyl cellulose (HEMC). Species of the compound may be included.

The cellulose ether compound may not include carboxymethyl cellulose (CMC). The viscosity of the cellulose ether compound may be between 4,000 cps and 80,000 cps. Method for producing coal briquettes according to an embodiment of the present invention may further comprise the step of drying the mixture after the step of mixing by adding water to the mixture.

In the step of providing a mixture, the pulverized coal may be further mixed with one or more binders selected from polyvinyl alcohol (PVA), lignin, and starch. In the step of providing coal briquettes, the amount of water contained in the coal briquettes may be 5wt% to 15wt%.

In the method for manufacturing coal briquettes according to an embodiment of the present invention, the coal briquettes are heated at 80 ° C. to 150 ° C. for 1 hour to 24 hours to adjust the amount of moisture contained in the coal briquettes to 5 wt% or less, and the compression load of the coal briquettes is 100 kgf or more. It may further comprise the step of adjusting to. The coal briquettes are hot air, steam, near infrared, microwave, liquid natural gas (LNG), liquid propane gas (LPG), FIG off gas (FOG), and coke oven gas (cokes oven). gas, COG) and blast furnace gas (BFG) may be heated by one or more heat sources selected from the group consisting of.

The method for producing molten iron according to an embodiment of the present invention includes the steps of i) providing coal briquettes prepared according to the above method, ii) providing reduced iron from iron ore in a reduction furnace, and iii) melting the coal briquettes and reduced iron. Charging the gasifier to provide molten iron. In the providing of reduced iron, the reduction furnace may be a fluidized bed reduction furnace or a packed bed reduction furnace.

Coal briquettes according to an embodiment of the present invention is charged into the dome portion of the molten gasifier in the molten iron manufacturing apparatus comprising a reducing gas which is i) a molten gasifier to which iron is charged, and ii) a molten gasifier, and providing a reduced iron. It is heated rapidly. The coal briquettes comprise 0.7 wt% to 2.0 wt% of cellulose ether compounds, 5 wt% to 15 wt% of water, and the remaining fine coal. More preferably, the amount of cellulose ether compound may be 0.8 wt% to 1.5 wt%.

The coal briquette manufacturing apparatus according to an embodiment of the present invention includes: i) pulverized coal hopper for storing pulverized coal, ii) binder hopper for storing water-soluble binder, iii) pulverized coal is supplied from pulverized coal hopper, and water-soluble binder is supplied from the binder hopper. A mixer for preparing a mixture of pulverized coal and a water-soluble binder, iv) a water supply unit for supplying water to the mixer, v) a molding apparatus for manufacturing coal briquettes by receiving a mixture from the mixer, and vi) a coal briquette provided from a molding apparatus. Heat-drying, a storage bin whose diameter gradually decreases from the bottom to the top, and vii) a heat source for supplying hot air for drying the coal briquettes to the bottom of the storage bin. The molten iron manufacturing apparatus according to an embodiment of the present invention is i) a coal briquette manufacturing apparatus described above, ii) a reducing furnace for providing reduced iron, and iii) a reduced iron connected to a reducing furnace, and is connected to a coal briquette manufacturing apparatus to obtain coal briquettes. It includes a molten gasifier for supplying molten iron. The reduction furnace may be a fluidized bed reduction furnace or a packed bed reduction furnace.

According to one embodiment of the present invention, by using a cellulose ether compound as a binder it can greatly improve the hot strength and cold strength of the coal briquettes. In addition, a cellulose ether compound can be used to prevent alkali from being deposited in the fluidized-bed reduction furnace. By heat-treating the coal briquettes to increase the compressive load of the coal briquettes can greatly improve the hot strength and cold strength of the coal briquettes manufactured using a water-soluble binder or water. In addition, the compression load of the coal briquettes can be increased in a short time through rapid and efficient heat treatment. In addition, it is possible to heat-treat the coal briquettes efficiently while minimizing costs by using heat sources in existing storage bins and steel mills.

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

FIG. 2 is a schematic diagram of an apparatus for manufacturing coal briquettes using the method of manufacturing coal briquettes of FIG. 1.

3 is a schematic view of a molten iron manufacturing apparatus including the coal briquette manufacturing apparatus of FIG. 2.

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

5 to 8 are graphs showing experimental results according to Experimental Examples 10 to 13 of the present invention, respectively.

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 in the specification, the meaning of “comprising” embodies a particular characteristic, region, integer, step, operation, element and / or component, and the presence of another characteristic, region, integer, step, operation, element and / or component or 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.

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 flowchart of the manufacturing method of the coal briquette of FIG. 1 is only for illustration of this invention, Comprising: This invention is not limited to this. Therefore, the manufacturing method of the coal briquettes can be variously modified. Meanwhile, the structure of the coal briquette manufacturing apparatus for implementing the method of manufacturing coal briquettes of FIG. 1 may be easily understood by those skilled in the art, and thus detailed description thereof will be omitted.

As shown in FIG. 1, the method of manufacturing coal briquettes includes providing fine coal (S10), mixing a powdered cellulose ether compound to provide a mixture (S20), and adding water to the mixture to mix it. (S30), and forming a mixture to provide coal briquettes (S40). In addition, if necessary, the method of manufacturing coal briquettes may further include other steps.

First, in step S10, pulverized coal is provided. As pulverized coal, raw materials containing carbon such as bituminous coal, subbituminous coal, anthracite and coke may be used. The particle size of pulverized coal can be adjusted to 4mm or less.

Next, in step S20, a cellulose ether compound is mixed with pulverized coal to provide a mixture. That is, the cellulose ether compound is added to the pulverized coal and then the mixture is mixed well so as to be uniformly mixed.

Here, a powdered cellulose ether compound is used rather than the liquid phase. In the case of using a binder solution, a carboxymethyl cellulose (CMC) solution having a low viscosity of the binder itself may be used to improve flowability. However, since a binder having a low viscosity is used, there is a problem that the strength of coal briquettes is lowered. In addition, the binder in the form of a solution is difficult to maintain the binder component uniformly due to the separation of the layer, the transport cost is high because a special transport vehicle such as tank lorry is required during the transfer. In addition, the binder solution freezes during the winter months, so storage is not easy.

In contrast, when the powdered cellulose ether compound is used as the binder, the coal briquettes having excellent strength can be produced because the viscosity of the cellulose ether compound itself is high. In addition, since the cellulose ether compound is used in a powder form, it is easy to store by minimizing its volume, and there is an advantage of easy transportation. Furthermore, there is no need to worry about freezing during the winter season. It is therefore suitable to use powdered cellulose ether compounds.

The viscosity of the cellulose ether compound may be between 4,000 cps and 80,000 cps. The viscosity of the cellulose ether compound refers to a value obtained by measuring the viscosity of an aqueous solution of a cellulose ether compound having a concentration of 2% by weight at 20 ± 0.1 ° C. using Brookfield's DV-II + Pro (spindle HA). When the viscosity of the cellulose ether compound is too low, the viscosity of the solution containing the cellulose ether compound, for example, an aqueous solution, is too low, thereby lowering the binding force to the pulverized coal. As a result, the strength of the coal briquettes may be lowered. On the other hand, when the viscosity of a cellulose ether compound is too high, since the molecular weight of a cellulose ether compound is too high and water solubility falls, binding force with respect to pulverized coal is not enough. Therefore, it is preferable to adjust the viscosity of a cellulose ether compound to the above-mentioned range.

The cellulose ether compound may include methyl cellulose (MC), hydroxyethyl cellulose (HEC), hydroxypropyl cellulose (HPC), hydroxypropyl methyl cellulose (HPMC) or hydroxyethyl methyl cellulose (HEMC). Methyl cellulose (MC) has a methyl group substitution degree of 18 to 32wt%, hydroxyethyl cellulose (HEC) has a hydroxyethyl group substitution degree of 20 to 80wt%. And hydroxypropyl cellulose (HPC) has a hydroxypropyl group substitution degree of 20 to 80wt%, hydroxypropyl methyl cellulose (HPMC) has a methyl group substitution degree of 18 to 32wt% and a hydroxypropyl group of 2-14wt% It has a degree of substitution. In addition, the hydroxyethyl methyl cellulose (HEMC) may have a degree of substitution of 18 to 32 wt% methyl group and a degree of substitution of 2 to 14 wt% hydroxyethyl group.

On the other hand, the average particle size of the powdered cellulose ether compound may be 50㎛ to 100㎛. When the particle size of the powdered cellulose ether compound is too small, the production process cost increases. In addition, when the particle size of the cellulose ether compound is too large, the specific surface area of the cellulose ether compound is small, its water solubility is lowered, and the strength of the coal briquettes manufactured using the cellulose ether compound may be lowered. Therefore, it is preferable to adjust the particle size of the powdered cellulose ether compound to the above-mentioned range. On the other hand, more specifically, the average particle size of the powdered cellulose ether compound may be 78㎛. In this case, the particle size of the powdered cellulose ether compound may be 97% or more in 0.18 mm or less.

The ratio of the average particle size of the pulverized coal to the average particle size of the cellulose ether compound may be 7 to 30. More specifically, the ratio of the average particle size of the pulverized coal to the average particle size of the cellulose ether compound may be 10 to 20. If the ratio of the average particle size is too large or too small, the cellulose ether compound may not sufficiently express the binding capacity in the pulverized coal as a binder. Therefore, it is preferable to keep the ratio of average particle size in the above-mentioned range.

Next, in step S30, water is added to the mixture and mixed. When water is added to the mixture in which the powdery cellulose ether compound is uniformly distributed, the cellulose ether compound dispersed in the pulverized coal is dissolved in water. As a result, the dissolved cellulose ether compound can exhibit the bonding force with the pulverized coal and can greatly improve the strength of the coal briquettes produced in the subsequent process. As described above, the coal briquettes having excellent strength and minimizing the process cost are separated by mixing water with a mixture of a powdered cellulose ether compound and pulverized coal without first mixing the liquid binder with pulverized coal. It can manufacture.

On the other hand, the mixing time in step S30 is greater than the mixing time in step S20. That is, in step (S20), since the pulverized coal and the cellulose ether compound of the powder type are used, uniform mixing is possible even for a short time by mixing the solid and the solid. On the other hand, in step (S30) it is necessary to dissolve in powdered pulverized coal uniformly by contacting the powdered cellulose ether compound mixed with pulverized coal in the step (S20), so mixing for a long time than the step (S20) in terms of process efficiency desirable. More preferably, the ratio of the mixing time in step S30 to the mixing time in step S20 may be 2-5. If the aforementioned ratio is too small, the powdered cellulose ether compound mixed with the pulverized coal may not be in sufficient contact with water, and thus the strength of the coal briquettes may be lowered. On the contrary, when the above ratio is too large, it is not preferable in terms of process efficiency. Therefore, it is desirable to adjust the above ratio appropriately.

On the other hand, although not shown in Figure 1, it may be added after the step (S30) to dry the mixture. That is, when it is necessary to control the moldability of the mixture containing the pulverized coal, the powdered cellulose ether compound and the water, the mixture may be dried to remove some moisture. As a result, the strength of the coal briquettes produced in a subsequent step can be greatly improved.

Finally, in step S40, the mixture is molded to provide coal briquettes. For example, coal briquettes in the form of pockets or strips can be produced by charging and compressing the mixture between a pair of rollers. As a result, coal briquettes having excellent hot strength and cold strength can be produced. Here, the amount of the cellulose ether compound contained in the coal briquettes may be 0.7wt% to 2.0wt%. More preferably, the amount of cellulose ether compound may be 0.8 wt% to 1.5 wt%. If the amount of cellulose ether compound is too large, the cost of manufacturing coal briquettes rises. In addition, when the amount of the cellulose ether compound is too small, the sufficient binding force is not expressed and the strength of the coal briquettes is lowered. Therefore, it is preferable to adjust the amount of the cellulose ether compound in the above-mentioned range.

On the other hand, the amount of water contained in the coal briquettes may be 5wt% to 15wt%. More preferably, the amount of moisture may be 7 wt% to 12 wt%. If the amount of water is too large, there is a problem that the molding of the mixture is difficult. In addition, when the amount of moisture is too small, the cold strength of the coal briquettes may be lowered. Therefore, the amount of moisture is adjusted to the above range.

The coal briquettes prepared by the above-described method include 0.7 wt% to 2.0 wt% of cellulose ether compounds, 5 wt% to 15 wt% of water, and the remaining fine coal. More specifically, the amount of cellulose ether compound may be 0.8wt% to 1.5wt%. Here, when the amount of the cellulose ether compound is too large, the production cost of coal briquettes is greatly increased. In addition, when the amount of the cellulose ether compound is too small, the strength of the coal briquettes is lowered. Therefore, it is preferable to adjust the amount of the cellulose ether compound in the above-mentioned range. In addition, when the amount of water is too large, the formability of the coal briquettes is lowered. In addition, when the amount of moisture is too small, the cold strength of the coal briquettes may be lowered. Therefore, the moisture content of the coal briquettes is adjusted to the above range.

Although not shown in FIG. 1, a binder such as PVA (polyvinyl alcohol, polyvinyl alcohol), lignin, or starch may be further mixed in addition to the cellulose ether compound described above in step S20. These binders have the same water solubility as the cellulose ether compound. The amount of water contained in the coal briquettes manufactured using the binder may be 5 wt% to 15 wt%. Since water is used or water is added in step S30, after the coal briquettes are manufactured, the coal briquettes may be heated to reduce the amount of moisture contained in the coal briquettes. That is, the coal briquettes are heated at 80 ° C. to 150 ° C. for 1 to 24 hours to adjust the amount of moisture contained in the coal briquettes to 5 wt% or less.

Heat treatment conditions may be enhanced or moderated depending on the moisture content of the coal briquettes. If the heating temperature of the coal briquettes is too low, the moisture contained in the coal briquettes are not evaporated well, the heat treatment effect is lowered, the heat treatment time is increased, the productivity is lowered. In addition, when the heating temperature of the coal briquettes is too high, the volatiles contained in the coal briquettes may be lost while cracking in the coal briquettes, and the compressive load is rather lowered because only the moisture content is lowered due to exposure to high temperatures. Therefore, the heating temperature of coal briquettes is adjusted to the above-mentioned range. On the other hand, the higher the coal briquette heating temperature can shorten the heat treatment time, but in order to shorten the heating time to less than 1 hour, a high temperature hot air must be applied to the volatile matter contained in the coal briquettes. Moreover, when heat processing time is too long, productivity will fall. Therefore, the heating time of the coal briquettes is adjusted to the above-mentioned range. On the other hand, the compression load of the coal briquettes can be adjusted to 100kgf or more. Hereinafter, the heating unit of the coal briquettes, etc. will be described in more detail with reference to FIG. 2.

FIG. 2 schematically shows a coal briquette manufacturing apparatus 60 to which the coal briquette manufacturing method of FIG. 1 is applied. The structure of the coal briquette manufacturing apparatus 60 of FIG. 2 is merely for illustrating the present invention, and the present invention is not limited thereto. Therefore, the coal briquette manufacturing apparatus may be modified differently.

As shown in FIG. 2, the coal briquette manufacturing apparatus 60 includes a pulverized coal hopper 61, a binder hopper 62, a water supply unit 63, a mixer 64, a molding apparatus 65, and a heat treatment unit 66. Include. In addition, the coal briquette manufacturing apparatus 60 may further include other devices as necessary. Pulverized coal is stored in the pulverized coal hopper 61, and a binder is stored in the binder hopper 62. Examples of the binder include the above-described cellulose ether compound, PVA (polyvinyl alcohol, polyvinyl alcohol), lignin or starch. The mixer 64 prepares a mixture by mixing the pulverized coal and a binder supplied from the pulverized coal hopper 61 and the binder hopper 62, respectively. The water supply unit 63 is connected to the mixer 64 to supply water to the mixer 64. The molding apparatus 65 receives the mixture from the mixer 64 to form the coal briquettes by molding the mixture. The molding apparatus 65 uses a pair of rolls that rotate in opposite directions to charge the mixture therebetween, compress it, and discharge it downward. The heat treatment unit 66 dries the coal briquettes to improve the compression load of the coal briquettes.

More specifically, the heat treatment unit 66 includes a storage bin 661, a blower 663, a heat source 665, and a dust collector 667. In addition, the heat treatment unit 66 may further include other devices. The storage bin 661 stores the coal briquettes discharged from the forming apparatus 65 to the lower portion, and discharges the dried coal briquettes to the lower portion thereof. The level of coal briquettes stored in the storage bin 661 is maintained at an appropriate level so that coal briquettes are not destroyed by the heat treatment time or the compression load thereof. The storage bin 661 has a funnel shape to increase the contact area between hot air and coal briquettes.

As shown in FIG. 2, the blower 663 receives heat from the heat source 667 that generates thermal energy and forcibly transfers the heat to the storage bin 661. Hot air can be produced using steam, near infrared rays or microwaves as a heat source. The hot air can also be produced using commercialized fuels such as liquid natural gas (LNG) or liquid propane gas (LPG). Alternatively, molten iron manufacturing exhaust gas (Finex off gas, FOG), coke oven gas (COG) or blast furnace gas (BFG) in a steel mill may be used. The heat source 67 may be directly heated like an electric heater, or may recover and use waste heat generated in an ironworks, such as slag sensible heat and waste heat generated when oxidation of reduced iron of fine powder occurs.

The storage bin 661 has a structure in which its cross-sectional area gradually widens from the bottom to the top. Therefore, since hot air rises from the lower part of the storage bin 661 toward the upper part, the coal briquettes can be efficiently dried while removing the moisture contained in the coal briquettes. The dried coal briquettes are discharged to the lower portion of the storage bin 661.

Although not shown in FIG. 2, a discharge device may be provided below the storage bin 661. The discharge device constantly discharges the coal briquettes at a speed within 50 t / h. Meanwhile, steam of the coal briquettes discharged from the storage bin 661 is discharged to the outside after the dust is filtered while passing through the dust collector 667. If the temperature of the water vapor is lowered above the saturated water vapor pressure, condensed water may be produced. Therefore, although not shown in FIG. 2, a thermostat can be provided so that condensed water does not flow back into the storage bin 661.

As described above, by heat-treating the coal briquettes using the storage bin 661 that functions as an intermediate buffer during the coal briquette transfer process, it is possible to manufacture coal briquettes having sufficient strength efficiently in a short time without investing a separate facility. Therefore, the cold strength of the coal briquettes can be secured within a short time by heating the coal briquettes even when the binder and water are used together or the coal briquettes in which the binder itself has a high water content as a water-soluble and sufficient strength is not initially secured.

FIG. 3 schematically illustrates an apparatus for manufacturing molten iron 200 including the apparatus for manufacturing coal briquettes of FIG. 2. 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.

As shown in FIG. 3, the apparatus for manufacturing molten iron 200 includes a molten gasifier 60 and a packed-bed reduction reactor 20. In addition, other devices may be included as needed. In the packed-bed reduction furnace 20, iron ore is charged and reduced. The iron ore charged in the packed-bed reduction furnace 20 is made of reduced iron while passing through the packed-bed reduction furnace 20 after being pre-dried. The packed-bed reduction furnace 20 is a packed-bed reduction furnace, receives a reducing gas from the melt gasifier 60 to form a packed bed therein.

Since the coal briquettes manufactured by the manufacturing method of FIG. 1 are charged into the molten gasifier 60, a coal filling layer is formed inside the molten gasifier 60. The dome part 601 is formed in the upper part of the melt gasifier 60. That is, a wider space is formed than the other parts of the melt gasifier 60, where a high temperature reducing gas exists. Therefore, the coal briquettes charged into the dome part 601 by the high temperature reducing gas are converted into char by a pyrolysis reaction. The char generated by the pyrolysis reaction of the coal briquettes moves to the lower portion of the molten gasifier 60 to exothermicly react with oxygen supplied through the tuyere 30. As a result, the coal briquettes can be used as a heat source for keeping the molten gasifier 60 at a high temperature. On the other hand, because it provides air permeability, a large amount of gas generated in the lower portion of the melt gasifier 60 and reduced iron supplied from the packed-bed reduction reactor 20 makes the coal-filled layer in the melt gasifier 60 more easily and uniformly. Can pass.

In addition to the coal briquettes described above, a bulk coal material or coke may be charged into the melt gasifier 60 as necessary. On the outer wall of the molten gasifier 60 is provided with a tuyere 30 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 shows another apparatus for manufacturing molten iron 300 including the apparatus for manufacturing coal briquettes of FIG. 2. 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 300 includes a molten gasifier 60, a fluidized bed reduction furnace 22, a reduced iron compression device 40, and a compressed reduced iron storage tank 50. Here, the reduced reduced iron storage tank 50 can be omitted.

The manufactured coal briquettes are charged into a molten gasifier 60. Here, the coal briquettes generate a reducing gas in the melt gasifier 60, and the generated reducing gas is supplied to the fluidized-bed reduction furnace 22. The iron ore is supplied to the plurality of reducing furnaces 22 having a fluidized bed, and is made of reduced iron while flowing by the reducing gas supplied from the melt gasifier 60 to the fluidized bed reducing furnace 22. The reduced iron is compressed by the reduced iron compression device 40 and then stored in the reduced reduced iron storage tank (50). The compressed reduced iron is charged together with the coal briquettes from the compressed reduced iron storage tank 50 together with the coal briquettes and melted in the molten gasifier 60. Since the coal briquettes are supplied to the molten gasifier 60 and changed into air permeable, a large amount of gas and compressed reduced iron generated in the lower part of the molten gasifier 60 make the coal filling layer in the molten gasifier 60 easier and more uniform. It can be passed through to provide high quality molten iron.

On the other hand, the coal briquettes use a cellulose ether compound other than molasses as a binder, so that the alkali component can be significantly reduced. Therefore, the phenomenon in which an alkali such as potassium is deposited on the dispersion plate (not shown) or the cyclone (not shown) in the fluidized-bed reduction furnace 22 by the molasses containing a high alkali component can be prevented in advance.

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.

성형탄의Coal briquettes 열간강도Hot strength 및 And 냉간강도Cold strength 측정 실험 Measurement experiment

실험예Experimental Example

Fine powder of less than 3.4mm and cellulose ether compound powder of 0.2mm or less were uniformly mixed for 1 minute, and then mixed with water for 3 minutes to prepare a mixture. Pulverized coal was used as a mixture of strong coking coal, fine coal and powdered coke, and cellulose ether compound was used as hydroxypropyl methyl cellulose (HPMC, Mecelose ^® ) manufactured by Samsung Fine Chemicals. Then, the mixture was charged between a pair of rolls to produce coal briquettes. In this case, the pair of rolls pressurized the mixture at a pressure of 20 kN / cm to produce a pillow-shaped coal briquette having a size of 64.5 mm x 25.4 mm x 19.1 mm. Detailed manufacturing process of the remaining coal briquettes can be easily understood by those skilled in the art, and detailed description thereof will be omitted.

실험예Experimental Example 1 One

100 g of pulverized coal having a water content of 7.6% and an average particle size of 1.1 mm and 1 g of HPMC powder having an average particle size of 78 μm and a viscosity of 28,000 cps were mixed first, and then mixed again by adding 10 g of water. The mixture was charged between a pair of rolls to produce coal briquettes. The rest of the experimental procedure was the same as the above-described experimental example.

실험예Experimental Example 2 2

100 g of pulverized coal having a water content of 7.7% and an average particle size of 1.1 mm and 0.8 g of HPMC powder having an average particle size of 78 μm and a viscosity of 28,000 cps were mixed first, and then mixed again by adding 10 g of water. The mixture was charged between a pair of rolls to produce coal briquettes. The rest of the experiment was the same as in Experiment 1 described above.

실험예Experimental Example 3 3

100 g of pulverized coal having a moisture content of 1.4% and an average particle size of 1.1 mm and 1 g of HPMC powder having an average particle size of 78 μm and a viscosity of 28,000 cps were mixed first, and then mixed again by adding 10 g of water. The mixture was charged between a pair of rolls to produce coal briquettes. The rest of the experiment was the same as in Experiment 1 described above.

실험예Experimental Example 4 4

100 g of pulverized coal having a water content of 0.1% and an average particle size of 0.9 mm and 1 g of HPMC powder having an average particle size of 78 μm and a viscosity of 28,000 cps were mixed first, and then mixed again by adding 10 g of water. The mixture was charged between a pair of rolls to produce coal briquettes. The rest of the experiment was the same as in Experiment 1 described above.

실험예Experimental Example 5 5

100 g of pulverized coal having a water content of 5.7% and an average particle size of 1.0 mm and 1 g of HPMC powder having an average particle size of 82 μm and a viscosity of 60,000 cps were mixed first, and then mixed again by adding 10 g of water. The mixture was charged between a pair of rolls to produce coal briquettes. The rest of the experiment was the same as in Experiment 1 described above.

실험예Experimental Example 6 6

100 g of pulverized coal having a moisture content of 6.0% and an average particle size of 1.0 mm and 1 g of HPMC powder having an average particle size of 75 μm and a viscosity of 12,200 cps were mixed first, and then mixed again by adding 10 g of water. The mixture was charged between a pair of rolls to produce coal briquettes. The rest of the experiment was the same as in Experiment 1 described above.

실험예Experimental Example 7 7

100 g of pulverized coal having a moisture content of 6.1% and an average particle size of 1.0 mm and 1 g of HPMC powder having an average particle size of 77 μm and a viscosity of 49,000 cps were mixed first, and then mixed again by adding 10 g of water. The mixture was charged between a pair of rolls to produce coal briquettes. The rest of the experiment was the same as in Experiment 1 described above.

비교예Comparative example 1 One

100 g of pulverized coal having a water content of 7.6% and an average particle size of 1.1 mm and 0.6 g of HPMC powder having an average particle size of 78 μm and a viscosity of 28,000 cps were mixed first, and then mixed again by adding 10 g of water. The mixture was charged between a pair of rolls to produce coal briquettes. The rest of the experiment was the same as in Experiment 1 described above.

비교예Comparative example 2 2

100 g of pulverized coal having a water content of 5.7% and an average particle size of 1.0 mm and 0.2 g of HPMC powder having an average particle size of 82 μm and a viscosity of 60,000 cps were mixed first, and then mixed again by adding 10 g of water. The mixture was charged between a pair of rolls to produce coal briquettes. The rest of the experiment was the same as in Experiment 1 described above.

비교예Comparative example 3 3

100 g of pulverized coal having a moisture content of 1.4% and an average particle size of 1.1 mm and 1 g of HPMC powder having an average particle size of 75 μm and a viscosity of 2,080 cps were mixed first, and then mixed again by adding 10 g of water. The mixture was charged between a pair of rolls to produce coal briquettes. The rest of the experiment was the same as in Experiment 1 described above.

비교예Comparative example 4 4

100 g of pulverized coal with 0.1% water content and 1.0 mm average particle size, 1 g of carboxymethyl cellulose (CMC) (ASHILAND, AQUALONTM) powder with an average particle size of 70 μm and a viscosity of 6,000 cps were mixed first, followed by 12 g of water. And mixed again to prepare a mixture. The mixture was charged between a pair of rolls to produce coal briquettes. The rest of the experiment was the same as in Experiment 1 described above.

실험결과Experiment result

Drop strength and compression load of the coal briquettes manufactured according to Experimental Examples 1 to 6 described above were measured. The drop strength of the coal briquettes was determined from the ratio of coal briquettes having a particle size of +20 mm or more after 2 kg of coal briquettes were freely dropped four times at a height of 5 m. In addition, the compression load of the coal briquettes was measured at the maximum load until the coal briquettes were destroyed by applying a constant speed pressure, and measured by the average value of 20 coal briquette samples, and the results are shown in Table 1 below.

Table 1

As shown in Table 1, in the case of using HPMC having a viscosity of 12,200cps to 60,000cps in 0.8 to 1.0 parts by weight in Experimental Examples 1 to 7, the drop strength and compression load of the coal briquettes were excellent. Therefore, it was found that it is desirable to adjust the viscosity of HPMC to the above-mentioned range. In contrast, it was confirmed that the drop strength and the compressive load of the coal briquettes prepared according to Comparative Examples 1 to 4 were much smaller than the drop strength and the compressive load of the coal briquettes prepared according to Experimental Examples 1 to 7. Therefore, it was confirmed that coal briquettes manufactured using HPMC were much better in terms of drop strength and compressive load than coal briquettes manufactured using CMC.

성형탄 Ash 제조 조업 실험Briquette Ash Manufacturing Operation Experiment

실험예 8Experimental Example 8

The coal briquettes prepared according to Experimental Example 1 were crushed into fine powder, and about 7 g of finely divided coal briquettes were put into a 30 ml porcelain crucible, and burned by heating at 850 ° C. Box Furnace for 10 hours. Since the rest of the experimental procedure can be easily understood by those skilled in the art, detailed description thereof will be omitted.

실험예 9Experimental Example 9

HPMC and CMC solution was uniformly mixed with pulverized coal to prepare a mixture. 100 g of pulverized coal with a water content of 0.1% and an average particle size of 1.0 mm and 7.5 g of hydroxypropyl methyl cellulose (HPMC, Samsung Fine Chemicals, Mecellose ^® , viscosity 28,000 cps) 4% aqueous solution and 7.5 g of carboxymethyl cellulose ( CMC, ASHILAND, AQUALONTM, viscosity 6,000 cps) 6% aqueous solution was used. Then, the mixture was charged between a pair of rolls to produce coal briquettes. In this case, the pair of rolls pressurized the mixture at a pressure of 20 kN / cm to produce a pillow-shaped coal briquette having a size of 64.5 mm x 25.4 mm x 19.1 mm. The coal briquettes thus prepared were crushed into fine powder, and about 7 g of finely divided coal briquettes were put into a 30 ml porcelain crucible and burned by heating at 850 ° C. Box Furnace for 10 hours. The rest of the experimental procedure was the same as in Experimental Example 8 described above.

비교예 5Comparative Example 5

The coal briquettes prepared according to Comparative Example 4 described above were crushed into fine powder, and about 7 g of finely divided coal briquettes were put into a 30 ml porcelain crucible, and heated and burned at 850 ° C. Box Furnace for 10 hours. The rest of the experimental procedure was the same as in Experimental Example 8 described above.

실험결과Experiment result

According to Experimental Example 8, Experimental Example 9 and Comparative Example 5, the ash components remaining in the operation were analyzed. The experimental results of Experimental Example 8, Experimental Example 9, and Comparative Example 5 described above are shown in Table 2 below. Table 2 shows the ash components contained in the coal briquettes prepared according to Experimental Example 8, Experimental Example 9 and Comparative Example 5.

TABLE 2

As shown in Table 2, Na ₂ O content in the alkali contained in the ash was low as 0.39 in Experimental Example 8, but Na ₂ O content was very high as 2.64 in Comparative Example 5. In addition, in Experiment 9, the Na ₂ O content was 1.59. This is because the Na ions are bonded to the functional group of the CMC, it can be seen that when the coal briquettes are manufactured using the CMC solution, alkali may be included in the reducing gas, which may adversely affect the operation of the fluidized bed reduction furnace.

성형탄의Coal briquettes 압축하중 측정 실험 Compression Load Measurement Experiment

A fine coal for coal briquettes having an average property used for molten reduced iron and a binder were prepared and mixed. Pulverized coal had a particle size of 3.4 mm or less. The pulverized coal was further mixed with a carbon source additive. As a cellulose ether compound binder, Ferrobine ^™ binder provided by Samsung Fine Chemicals Co., Ltd. was used. 1 part by weight of the binder was added to 100 parts by weight of pulverized coal, and 7 parts by weight of water was added and mixed uniformly. Then, the mixture was charged between a pair of rolls to produce coal briquettes. In this case, the pair of rolls pressurized the mixture at a pressure of 20 kN / cm to produce pillow shaped coal briquettes having a size of 64.5 mm x 25.4 mm x 19.1 mm. The coal briquettes prepared were heat-treated in a well-heated oven to evaporate moisture. Water and compression loads were measured using 20 coal briquettes manufactured. The compression load of the coal briquettes was measured by the maximum load until the coal briquettes were destroyed by applying a constant pressure and obtained from an average value of 20 coal briquette samples. The rest of the experimental procedure can be easily understood by those skilled in the art, and detailed description thereof will be omitted.

실험예Experimental Example 10 10

The coal briquettes having an initial moisture content of 8.8 wt% and a compression load of 40 kgf were heat-treated at a temperature of 80 ° C. for 24 hours in a heat treatment oven to dry coal briquettes.

실험예Experimental Example 11 11

The coal briquettes having an initial moisture content of 10.1 wt% and a compressive load of 51 kgf were heat-treated for 5 hours at a temperature of 100 ° C. in a heat treatment oven to dry coal briquettes.

실험예Experimental Example 12 12

The coal briquettes having an initial moisture content of 9.7 wt% and a compressive load of 52 kgf were heat-treated in a heat treatment oven at a temperature of 120 ° C. for 5 hours to dry coal briquettes.

실험예Experimental Example 13 13

The coal briquettes having an initial moisture content of 9.2 wt% and a compressive load of 51 kgf were heat-treated in a heat treatment oven at a temperature of 150 ° C. for 5 hours to dry coal briquettes.

비교예Comparative example 6 6

Coal briquettes prepared in the same manner as in Experimental Example 10 described above were stored at room temperature for 24 hours.

비교예Comparative example 7 7

Coal briquettes prepared in the same manner as in Comparative Example 6 described above were heat treated at 60 ° C.

비교예Comparative example 8 8

The coal briquettes manufactured in the same manner as in Comparative Example 6 described above were heat treated at 200 ° C.

실험결과Experiment result

As a result, in Comparative Example 6, which was not subjected to heat treatment, the coal briquettes initially showed a compression load of 40 kgf, and after 24 hours at room temperature, the compression load was 70 kgf. Even when the coal briquettes were heat treated at 60 ° C. as in Comparative Example 7, sufficient compressive load was not obtained. Even in Comparative Example 8, which was heat-treated at a high temperature of 200 ° C., cracks occurred, and thus the appearance of the coal briquettes was not maintained.

5 to 8 show the compression load measurement test results of the coal briquettes according to Experimental Examples 10 to 13, respectively.

5 to 8, the compressive load of the coal briquettes was excellent as 294kgf in Experimental Example 10, 217kgf in Experimental Example 11, 3491kgf in Experimental Example 12, and 307kgf in Experimental Example 13, respectively. In Experimental Examples 11 to 13, although the compressive load of the coal briquettes slightly decreased over time, it was found that it is preferable to adjust the heat treatment conditions of the coal briquettes to the above-mentioned ranges.

In contrast, the compressive load of the coal briquettes prepared according to Comparative Examples 6 to 8 was much smaller than that of the coal briquettes prepared according to Experimental Examples 10 to 13. Therefore, it could be confirmed that the compression load of the coal briquettes varies depending on whether the heat treatment is performed.

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.

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 method for manufacturing coal briquettes which is charged into the dome portion of the molten gasifier rapidly heated;

Providing pulverized coal,

Mixing a powdered cellulose ether compound with the pulverized coal to provide a mixture,

Adding water to the mixture to mix, and

Molding the mixture to provide coal briquettes

Including,

In the step of providing the coal briquettes, the amount of cellulose ether compound contained in the coal briquettes is 0.7wt% to 2.0wt% method of producing coal briquettes.
In claim 1,

The amount of the cellulose ether compound is 0.8wt% to 1.5wt% of the method for producing coal briquettes.
In claim 1,

In the step of providing the coal briquettes, the amount of water contained in the coal briquettes is 5wt% to 15wt% manufacturing method of coal briquettes.
In claim 3,

The amount of water contained in the coal briquettes is 7wt% to 12wt% manufacturing method of coal briquettes.
In claim 1,

The ratio of the amount of water contained in the coal briquettes to the amount of the cellulose ether compound contained in the coal briquettes is 5 to 40.
In claim 1,

The ratio of the amount of water contained in the coal briquettes to the amount of the cellulose ether compound contained in the coal briquettes is 7 to 20.
In claim 1,

In the step of providing the mixture, the average particle size of the cellulose ether compound is 50㎛ 100㎛ manufacturing method of coal briquettes.
In claim 1,

In the providing of the mixture, the ratio of the average particle size of the pulverized coal to the average particle size of the cellulose ether compound is 7 to 30.
In claim 1,

The ratio of the average particle size of the pulverized coal to the average particle size of the cellulose ether compound is 10 to 20.
In claim 1,

The mixing time in the providing of the mixture is less than the mixing time in the mixing by adding water to the mixture, and providing the mixture for the mixing time in the mixing by adding water to the mixture. The ratio of the mixing time in the method of producing coal briquettes is 2 to 5.
In claim 1,

The cellulose ether compound is at least selected from the group consisting of methyl cellulose (MC), hydroxyethyl cellulose (HEC), hydroxypropyl cellulose (HPC), hydroxypropyl methyl cellulose (HPMC) and hydroxyethyl methyl cellulose (HEMC) The manufacturing method of the coal briquettes containing 1 type of compound.
In claim 1,

The cellulose ether compound is a method for producing coal briquettes that do not contain carboxymethyl cellulose (CMC).
In claim 1,

The viscosity of the cellulose ether compound is 4,000 cps to 80,000 cps manufacturing method of coal briquettes.
In claim 1,

And drying the mixture after adding water to the mixture to mix the mixture.
In claim 1,

In the providing of the mixture, the coal briquettes are further mixed with at least one binder selected from PVA (polyvinyl alcohol, polyvinyl alcohol), lignin and starch.
The method of claim 15,

In the step of providing the coal briquettes, the amount of water contained in the coal briquettes is 5wt% to 15wt% manufacturing method of coal briquettes.
In claim 1,

The coal briquettes are heated at 80 ° C. to 150 ° C. for 1 hour to 24 hours to adjust the amount of water contained in the coal briquettes to 5 wt% or less, and to adjust the compression load of the coal briquettes to 100 kgf or more. Manufacturing method.
The method of claim 17,

The coal briquettes may include steam, near infrared rays, microwaves, liquid natural gas (Liquid Natural Gas, LNG), liquid propane gas (LPG), FIG off gas (FOG), and coke oven gas. COG) and blast furnace gas (BFG) method for producing coal briquettes heated by one or more heat sources selected from the group consisting of.
Providing the coal briquettes prepared according to claim 1,

Providing reduced iron reduced iron ore in a reduction furnace, and

Charging molten coal with the coal briquettes and the reduced iron to provide molten iron;

The molten iron manufacturing method comprising a.
The method of claim 19,

In the providing of the reduced iron, the reduction furnace is a molten iron manufacturing method is a fluidized bed reduction furnace or packed-bed reduction furnace.
A molten gas furnace in which reduced iron is charged, and

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

As a coal briquettes which is charged in the dome portion of the molten gasifier in the molten iron manufacturing apparatus comprising a rapid heating,

Coal briquettes comprising 0.7 wt% to 2.0 wt% of cellulose ether compounds, 5 wt% to 15 wt% of water, and remaining fine coal.
The method of claim 21,

Coal briquettes are an amount of the cellulose ether compound is 0.8wt% to 1.5wt%.
Pulverized coal hopper to store pulverized coal,

Binder hopper to store water soluble binders,

A mixer for receiving pulverized coal from the pulverized coal hopper and receiving a water-soluble binder from the binder hopper to produce a mixture of the pulverized coal and the water-soluble binder;

A water supply unit supplying water to the mixer,

Forming apparatus for receiving the mixture from the mixer to produce coal briquettes,

A storage bin which receives the coal briquettes from the molding apparatus and heat-drys the coal briquettes, the diameter of which gradually decreases from a lower portion to an upper portion, and

Heat source for supplying hot air drying the coal briquettes in the lower portion of the storage bin

Coal briquette manufacturing apparatus comprising a.
The coal briquette manufacturing apparatus according to claim 23,

A reducing furnace providing reduced iron, and

A molten gasifier that is connected to the reduction furnace to receive reduced iron and is connected to the coal briquette manufacturing apparatus to receive coal briquettes to produce molten iron.

Including,

The reduction furnace is molten iron manufacturing apparatus which is a fluidized bed reduction furnace or packed bed reduction furnace.