KR101766855B1

KR101766855B1 - Coal briquettes, method for manufacturing the same and method for manufacturing molten iron

Info

Publication number: KR101766855B1
Application number: KR1020150157550A
Authority: KR
Inventors: 박우일; 류진호; 김현정
Original assignee: 주식회사 포스코
Priority date: 2015-11-10
Filing date: 2015-11-10
Publication date: 2017-08-09
Also published as: KR20170054869A; WO2017082513A1; CN108350379A

Abstract

There is provided a molten steel producing apparatus including a melter-gasifier furnished with reduced iron, and a reducing furnace connected to the melter-gasifier furnishing a reduced iron, the molten iron being charged into the dome of the melter- The method for producing the molded coal includes the steps of: i) providing pulverized coal, ii) mixing pulverized coal with powdered cellulose ether compound to provide a blended coal, iii) preparing an aqueous solution containing polyvinyl alcohol; iv) adding an aqueous solution comprising polyvinyl alcohol to the blend to provide the blend and v) molding the blend to provide blast furnace.

Description

TECHNICAL FIELD [0001] The present invention relates to a method for producing molten iron,

A method for producing the same, and a method for manufacturing molten iron. More particularly, the present invention relates to a method of producing a molten metal, a method of manufacturing the same, and a method of manufacturing a molten iron, in which the order of the cellulose ether compound and the polyvinyl alcohol (PVA) is controlled to improve the binder performance while achieving uniform mixing.

In the melt reduction steelmaking method, a melting furnace for melting iron ores and a reduced iron ore is used. When molten iron ore is melted in a melter-gasifier, molten coal is charged into the melter-gasifier as a heat source for melting iron ore. Here, the reduced iron is melted in a melter-gasifier, converted to molten iron and slag, and then discharged to the outside. The briquetted coal charged into the melter-gasifier furnishes a coal-filled bed. Oxygen is blown through the tuyere installed in the melter-gasifier, and then the coal-packed bed is combusted to generate combustion gas. The combustion gas is converted into a hot reducing gas while rising through the coal packed bed. The high-temperature reducing gas is discharged to the outside of the melter-gasifier and supplied to the reducing furnace as a reducing gas.

Molded coal is produced by mixing pulverized coal and binder and then compressing. It is necessary to produce briquettes having excellent cold strength and hot strength in order to use them in the manufacture of molten iron. Therefore, the binder used in the briquetting coal should have the property of maintaining excellent adhesion and high strength at high temperature.

In one embodiment of the present invention, there is provided a method for producing a molded coal having excellent hot strength and cold strength by mixing PVA and a cellulose ether binder in accordance with characteristics.

The briquette according to one embodiment of the present invention is charged into a dome portion of a melter-gasifier in a molten iron manufacturing apparatus including i) a melter-gasifier furnished with reduced iron, and ii) a reducing furnace connected to a melter- And rapidly heated. The method for producing molded coal includes the steps of: i) providing pulverized coal, ii) mixing the pulverized coal with a pulverized cellulose ether compound to provide a blended coal, iii) preparing an aqueous solution containing polyvinyl alcohol; iv) adding an aqueous solution comprising polyvinyl alcohol to the blend to provide the blend and v) molding the blend to provide blast furnace.

In the step of providing the compounding carbon, the amount of the cellulose ether compound may be added in an amount of 0.3 part by weight to 0.7 part by weight based on 100 parts by weight of the pulverized coal.

The cellulose ether compound is at least one selected from the group consisting of methyl cellulose (MC), hydroxyethyl cellulose (HEC), hydroxypropyl cellulose (HPC), hydroxypropyl methyl cellulose (HPMC) and hydroxyethyl methyl cellulose Can be a species compound.

The average particle size of the cellulose ether compound may be 50 탆 to 100 탆.

The viscosity of the cellulose ether compound may be 4,000 cp to 80,000 cp.

The aqueous solution containing polyvinyl alcohol may contain 1 wt% to 10 wt% of the polyvinyl alcohol.

The polyvinyl alcohol may have a weight average molecular weight of 100,000 to 300,000.

The viscosity of the polyvinyl alcohol may be 28 cp to 47 cp.

The step of preparing an aqueous solution containing polyvinyl alcohol may be a step of dissolving powdery polyvinyl alcohol in water at a temperature of 60 ° C to 100 ° C.

In the step of providing the mixture by adding an aqueous solution containing polyvinyl alcohol to the blend, 6 to 10 parts by weight of an aqueous solution containing polyvinyl alcohol may be added to 100 parts by weight of the pulverized coal.

And drying the mixture before molding the mixture to provide the briquettes.

And drying the briquette after molding the mixture to provide the briquette.

The method of manufacturing molten iron according to an embodiment of the present invention includes the steps of providing the molten iron by the above-described method, providing reduced iron reduced in the reducing furnace, and charging molten steel and reduced iron into the melter- .

In the step of providing reduced iron, the reducing furnace may be a fluidized bed type reducing furnace or a packed bed type reducing furnace.

In the apparatus for producing molten iron including a melter-gasifier furnished with reduced iron and a reducing furnace connected to the melter-gasifier and providing a reduced iron, the molten gas is charged into the dome of the melter- , 0.3 wt% to 0.8 wt% of polyvinyl alcohol, 3 wt% to 13 wt% of water, and the remaining powdered coal, as the shaped coal to be blended.

From 0.4 wt% to 0.5 wt% of a cellulose ether compound, from 0.5 wt% to 0.6 wt% of polyvinyl alcohol, from 5 wt% to 11 wt% of water, and the remaining fine coal.

The order of the cellulose ether compound, the molasses, and the curing agent can be controlled to greatly improve the hot strength and the cold strength of the molded battery. Further, by using a cellulose ether compound having almost no alkali component to reduce the amount of molasses which has a high alkali content, the phenomenon of adhering to the reducing furnace due to the alkali component of the shaped coal can be reduced.

Fig. 1 is a schematic flow chart of a method of manufacturing a briquette according to an embodiment of the present invention.
Fig. 2 is a schematic view of an apparatus for producing molded articles according to an embodiment of the present invention.
Fig. 3 is a schematic view of a molten iron manufacturing apparatus using the briquettes manufactured in Fig. 1. Fig.
Fig. 4 is a schematic view of another molten iron manufacturing apparatus using the briquette produced in Fig. 1. Fig.

The terms first, second and third, etc. are used to describe various portions, components, regions, layers and / or sections, but are not limited thereto. These terms are only used to distinguish any moiety, element, region, layer or section from another moiety, moiety, region, layer or section. Thus, a first portion, component, region, layer or section described below may be referred to as a second portion, component, region, layer or section without departing from the scope of the present invention.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms as used herein include plural forms as long as the phrases do not expressly express the opposite meaning thereto. Means that a particular feature, region, integer, step, operation, element and / or component is specified and that the presence or absence of other features, regions, integers, steps, operations, elements, and / It does not exclude addition.

Unless otherwise defined, all terms including technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Commonly used predefined terms are further interpreted as having a meaning consistent with the relevant technical literature and the present disclosure, and are not to be construed as ideal or very formal meanings unless defined otherwise.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 schematically shows a flow chart of a method of manufacturing a briquette according to an embodiment of the present invention. The flow chart of the method of manufacturing the briquette of Fig. 1 is merely for illustrating the present invention, and the present invention is not limited thereto. Therefore, the method of manufacturing the briquette can be variously modified.

As shown in Fig. 1, the method for producing molded coal includes the steps of providing pulverized coal (S10), providing powdered cellulose ether compound to the pulverized coal to provide blended carbon (S20), adding an aqueous solution containing polyvinyl alcohol (S30) of adding an aqueous solution containing polyvinyl alcohol to the blend to provide a blend (S40), and molding the mixture to provide blasted blend (S50). In addition, if necessary, the method of manufacturing the molded coal may further include other steps.

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

Next, in step S20, powdered cellulose ether compound is mixed with pulverized coal to provide a blended coal. That is, after the cellulose ether compound is added to the pulverized coal, the blend is mixed well so as to be uniformly mixed.

Here, a powdery cellulose ether compound, not a liquid phase, is used. When a non-powdered solution of a cellulose ether compound is used, a carboxymethyl cellulose (CMC) solution having a low viscosity is used in order to improve flowability. However, since a binder having a low viscosity is used, there is a problem in that the strength of the briquette is lowered. In addition, the cellulose ether compound in the form of a solution has a disadvantage in that it is difficult to uniformly maintain the components due to the layer separation, and a special transportation vehicle such as a tanker is required for transportation, resulting in high shipping cost. Further, since the cellulose ether compound solution is freezing in the winter season, storage is not easy.

In contrast, when a powdery cellulose ether compound is used, since the viscosity of the cellulose ether compound itself is high, a molded coal having excellent strength can be produced. In addition, since the cellulose ether compound is used in a powder form, its volume can be minimized to facilitate storage, and transportation is advantageous. Furthermore, there is no need to worry about freezing in winter. Therefore, in one embodiment of the present invention, a powdered cellulose ether compound is used.

The amount of the cellulose ether compound may be 0.3 part by weight to 0.7 part by weight based on 100 parts by weight of the pulverized coal. When the amount of the cellulose ether compound is too small, a problem arises in that the strength of the briquette to be produced is not sufficient. If the amount of the cellulose ether compound is too large, there may arise a problem that the mixture adheres to the molding machine in a step S50 to be described later. Therefore, the amount of the cellulose ether compound can be controlled within the above-mentioned range.

The viscosity of the cellulose ether compound may be 4,000 cp to 80,000 cp. 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 DV-II + Pro (spindle HA) from Brookfield. When the viscosity of the cellulose ether compound is too low, the binding force to the pulverized coal is lowered. As a result, the strength of the briquette can be lowered. On the other hand, when the viscosity of the cellulose ether compound is too high, the molecular weight of the cellulose ether compound is too high and the water solubility is lowered, so that the binding force to the pulverized coal is not sufficient. Therefore, the viscosity of the cellulose ether compound can be adjusted 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).

Methylcellulose (MC) has a methyl group degree of substitution of 18 wt% to 32 wt%, and hydroxyethyl cellulose (HEC) has a hydroxyethyl substitution degree of 20 wt% to 80 wt%. And hydroxypropylmethylcellulose (HPMC) has a degree of methyl group substitution of 18 wt% to 32 wt% and a degree of methyl group substitution of 2 wt% to 14 wt% % Hydroxypropyl group substitution degree. In addition, hydroxyethylmethylcellulose (HEMC) may have a degree of methyl group substitution of 18 wt% to 32 wt% and a degree of substitution of hydroxyethyl group of 2 wt% to 14 wt%. The cellulose ether compound may not contain carboxymethyl cellulose (CMC).

On the other hand, the average particle size of the powdery cellulose ether compound may be 50 탆 to 100 탆. When the particle size of the powdery cellulose ether compound is too small, the production process ratio is increased. In addition, when the particle size of the cellulose ether compound is too large, the specific surface area of the cellulose ether compound becomes small, and the water solubility thereof decreases, so that the strength of the molded battery produced using the cellulose ether compound may be lowered. Therefore, it is preferable to adjust the particle size of the powdery cellulose ether compound to the above-mentioned range. On the other hand, more specifically, the average particle size of the powdery cellulose ether compound may be 78 탆. In this case, the particle size of the powdery cellulose ether compound may be 97% or more at 0.18 mm or less.

Next, in step S30, an aqueous solution containing polyvinyl alcohol is prepared. At this time, in order to uniformly dissolve the polyvinyl alcohol, powdery polyvinyl alcohol can be dissolved in water at a temperature of 60 ° C to 100 ° C. Concretely, powdery polyvinyl alcohol is added to water at a temperature of 60 ° C to 100 ° C and sufficiently dissolved for 5 minutes or more.

Polyvinyl alcohol having a weight average molecular weight of 100,000 to 300,000 may be used. When a 4% solution at room temperature is prepared, the viscosity is between 28 cp and 47 cp, and the degree of saponification is 88 to 99% You can choose.

In step S30, an aqueous solution containing polyvinyl alcohol may be prepared so as to include 1 wt% to 10 wt% of polyvinyl alcohol. When an aqueous solution containing too little polyvinyl alcohol is used, a relatively large amount of water is added, and as a result, the moisture content in the molded-in-mold to be produced is increased, which may cause a problem in the strength of the briquette. When an aqueous solution containing too much polyvinyl alcohol is used, a problem may arise in dispersion of the polyvinyl alcohol in the aqueous solution. Therefore, an aqueous solution having a concentration in the above-mentioned range can be used.

Step S30 is configured independently of steps S10 and S20 described above. That is, after step S10 and step S20, step S30 may be performed, and after step S30, steps S10 and S20 may be performed. It is also possible to carry out step S10 and step S20 and step S30 simultaneously.

Next, in step S40, an aqueous solution containing polyvinyl alcohol is added to the blend to provide a mixture. When an aqueous solution containing polyvinyl alcohol is added to a blend containing a powdery cellulose ether compound uniformly distributed therein, the cellulose ether compound dispersed in the pulverized coal is dissolved in an aqueous solution containing polyvinyl alcohol. As a result, the strength of the molded carbon produced by dissolving the cellulose ether compound exhibiting the bonding strength with the pulverized coal can be greatly improved. As described above, an aqueous solution containing polyvinyl alcohol is firstly mixed with a mixture of powdery cellulose ether compound and pulverized coal, without mixing the pulverized cellulose ether compound directly into pulverized coal, and the respective steps are separated to obtain an excellent strength It is possible to produce a molded coal having a minimized process cost.

The amount of the aqueous solution containing polyvinyl alcohol may be 6 to 10 parts by weight based on 100 parts by weight of the pulverized coal. When the added amount of the aqueous solution containing polyvinyl alcohol is too small, the amount of the polyvinyl alcohol to be added is decreased and the strength of the finally formed molded charcoal can be lowered. When the added amount of the aqueous solution containing polyvinyl alcohol is excessively large, water in the aqueous solution is added in a large amount, and the moisture content in the molded-in-mold to be produced becomes high, which may cause a problem in the strength of the briquette. Therefore, an aqueous solution having a concentration in the above-mentioned range can be used.

The amount of the solid content of the polyvinyl alcohol provided through the addition of the aqueous solution containing polyvinyl alcohol may be 0.3 to 0.8 wt% with respect to 100 wt% of the total molded bodys.

On the other hand, although not shown in FIG. 1, a step of drying the mixture after step S40 may be added. That is, when it is necessary to control the formability of the mixture to which the aqueous solution containing the pulverized coal, the powdery cellulose ether compound, and the polyvinylalcohol is added, the mixture may be dried to remove some moisture. As a result, it is possible to significantly improve the workability in the production of molded parts and the strength of the molded parts in subsequent steps.

Finally, in step S50, the mixture is molded to provide a blast furnace. For example, it is possible to manufacture molded pockets or strips by charging the mixture between a pair of rollers and pressing them. As a result, it is possible to produce briquette having excellent hot strength and cold strength.

Here, the amount of the cellulose ether compound contained in the briquette may be 0.3 wt% to 0.7 wt%. More preferably, the amount of the cellulose ether compound may be from 0.4 wt% to 0.5 wt%. If the amount of the cellulose ether compound is too large, the cost of producing the molded-in-a-bobble increases. In addition, when the amount of the cellulose ether compound is too small, sufficient bonding force can not be exhibited, and the strength of the molded-in-fire decreases. Therefore, it is preferable to adjust the amount of the cellulose ether compound to the above-mentioned range.

On the other hand, the amount of polyvinyl alcohol contained in the briquette may be 0.3 wt% to 0.8 wt%. More preferably, the polyvinyl alcohol may be from 0.5 wt% to 0.6 wt%.

On the other hand, the amount of moisture contained in the briquette may be 3 wt% to 13 wt%. More preferably, the amount of moisture can be from 5 wt% to 11 wt%. When the amount of water is too large, molding of the mixture is difficult. Further, when the amount of moisture is too small, the cold strength of the briquette can be lowered. Therefore, it is preferable to adjust the amount of water to the above-mentioned range.

Therefore, the briquettes produced by the above-mentioned method contain 0.3 wt% to 0.7 wt% of the cellulose ether compound, 0.3 wt% to 0.8 wt% of the polyvinyl alcohol, 3 wt% to 13 wt% of the moisture, and the remaining pulverized coal. More preferably from 0.4 wt% to 0.5 wt% of a cellulose ether compound, from 0.5 wt% to 0.6 wt% of polyvinyl alcohol, from 5 wt% to 11 wt% of water, and the remainder of the pulverized coal.

Fig. 2 schematically shows an apparatus 60 for producing a shaped coal to which the method for producing molded coal shown in Fig. 1 is applied. The structure of the apparatus for producing molded articles of Fig. 2 is merely for illustrating the present invention, and the present invention is not limited thereto. Therefore, the apparatus for producing molded articles of Fig. 2 can be modified into various forms.

The molded coal producing apparatus 60 includes a pulverized coal hopper 61 for storing pulverized coal and a cellulose ether hopper 62 for storing a cellulose ether compound, a dissolving tank 63 for dissolving PVA in hot water to provide a PVA aqueous solution, a pulverized coal hopper 61 ), A first mixer 64 for mixing the pulverized coal supplied from the cellulose ether hopper 62 and the cellulose ether compound, and a PVA aqueous solution supplied from the blending coal supplied from the first mixer 64 and the dissolution tank 63 And a molding machine 66 for molding the mixed mixture from the second mixer 65 and the second mixer 65 to produce a molded carbon. And a heat treatment unit for lowering the moisture content by heating the briquettes produced in the molding machine 66.

The molding machine 66 compresses and mixes the mixture to produce molded-in-carbon. For example, the molding machine 66 may include a pair of rollers, so that the blend can be charged and pressed between the rollers to produce molded pockets or strips.

The storage bins 67 store the briquettes produced by the molding machine 66. A discharge line 71 for discharging water vapor evaporated from the briquette is installed in the upper portion of the storage bell 67, The facility 72 is connected. Thus, the water vapor evaporated in the briquettes through the heat treatment is discharged to the dust collecting facility (72) for treatment. At this time, a condensing water may be generated when the temperature is lowered beyond the saturation water vapor pressure, so that a thermostat (not shown) may be further provided to prevent the condensed water from flowing back into the storage bin.

A hot air supply pipe (69) is installed at a lower side of the storage bin (67). The hot air supplied to the inside of the storage bin 67 through the hot air supply pipe 69 is moved upward to heat the molded coal to evaporate the moisture contained in the molded carbon. The blower 70 supplies hot air heated by the heat source 68 to the hot air supply pipe 69.

Fig. 3 schematically shows a molten iron manufacturing apparatus 100 using the shaped coal produced in Fig. The structure of the apparatus for manufacturing molten iron 100 of FIG. 3 is merely for illustrating the present invention, and the present invention is not limited thereto. Therefore, the apparatus for manufacturing molten iron 100 of FIG. 3 can be modified into various forms.

The molten iron manufacturing apparatus 100 of FIG. 3 includes a melter-gasifier 10 and a packed-bed reduction reactor 20. Other devices may also be included if desired. In the packed-bed reduction reactor (20), iron ore is charged and reduced. The iron ores to be charged into the packed-bed reduction reactor 20 are pre-dried and then made into reduced iron while passing through the packed-bed reduction reactor 20. The packed-bed reduction reactor (20) is a packed-bed reduction reactor and receives a reducing gas from the melter-gasifier (10) to form a packed bed therein.

Since the briquettes produced by the production method of Fig. 1 are charged into the melter-gasifier 10, a coal-filled layer is formed inside the melter-gasifier 10. A dome portion 101 is formed on the upper portion of the melter-gasifier 10. That is, a larger space is formed compared with other portions of the melter-gasifier 10, and a high-temperature reducing gas is present therein. Therefore, the briquettes charged into the dome portion 101 by the reducing gas at a high temperature are converted into air by thermal decomposition reaction. The gas generated by the pyrolysis reaction of the blast furnace moves to the lower part of the melter-gasifier 10 and exothermically reacts with the oxygen supplied through the tuyere 30. As a result, the briquettes can be used as a heat source for keeping the melter-gasifier 10 at a high temperature. On the other hand, since the ladle provides air permeability, a large amount of gas generated in the lower portion of the melter-gasifier 10 and the reduced iron supplied from the packed-bed reduction reactor 20 can more easily and uniformly make the coal packed bed in the melter- It can pass.

The lump gasification furnace 10 may be charged with lumpy carbonaceous material or coke as needed in addition to the above-mentioned shaped coal. A tuyere (30) is installed on the outer wall of the melter-gasifier (10) to blow oxygen. Oxygen is blown into the coal packed bed to form a combustion zone. The briquettes can be burned in the combustion zone to generate reducing gas.

Fig. 4 schematically shows an apparatus 200 for manufacturing molten iron using the shaped coal produced in Fig. The structure of the molten iron manufacturing apparatus 200 of FIG. 4 is merely for illustrating the present invention, and the present invention is not limited thereto. Therefore, the molten iron manufacturing apparatus 200 of FIG. 4 can be modified into various forms. Since the structure of the molten iron manufacturing apparatus 200 of FIG. 4 is similar to that of the molten iron manufacturing apparatus 100 of FIG. 3, the same reference numerals are used for the same parts and the detailed description thereof is omitted.

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

The produced briquettes are charged into the melter-gasifier (10). Here, the briquette generates a reducing gas in the melter-gasifier (10), and the generated reducing gas is supplied to the fluidized-bed reduction reactor (22). The minute iron ores are supplied to a plurality of reduction furnaces 22 having a fluidized bed and are made of reduced iron while flowing by the reducing gas supplied from the melter-gasifier 10 to the fluidized bed reduction reactor 22. The reduced iron is compressed by the reduced iron compactor 40 and then stored in the compacted iron storage tank 50. The compressed reduced iron is charged into the melter-gasifier (10) from the compressed-reduced iron storage tank (50) together with the blast furnace and melted in the melter-gasifier (10). A large amount of gas generated in the lower portion of the melter-gasifier 10 and the compressed reduced iron make the coal filler layer in the melter-gasifier 10 more easily and uniformly distributed in the melter-gasifier 10, To provide good quality molten iron.

On the other hand, since the molded body uses a cellulose ether compound and polyvinyl alcohol which have little alkaline components as a binder, the alkali component can be reduced. Therefore, molasses containing a high alkali component can alleviate the phenomenon that alkali such as potassium is deposited on the dispersion plate (not shown) or the cyclone (not shown) in the fluidized-bed reduction reactor 22 to be clogged.

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

Experimental Example

The pulverized coal having a diameter of 3.4 mm or less and the cellulose ether compound powder having a diameter of 0.2 mm or less were mixed to further blend the blend. Water at 80 캜 was added to the powdery PVA and mixed to prepare a PVA aqueous solution. A blend was prepared by adding a polyvinyl alcohol (PVA) aqueous solution to the blend. As the pulverized coal, a hard carbon, an untreated carbon powder and a minute coke were mixed and used. The cellulose ether compound used was a product of Hydroxyethyl methylcellulose (HEMC, PB401) of Samsung Fine Chemicals. PVA was used as a KURARAY POVAL product in Japan by mixing 50 wt% of PVA224 and PVA117. Then, the mixture was charged into a pair of rolls to produce a blast furnace. In this case, the pair of rolls were pressurized with a pressure of 20 kN / cm to produce a pillow-shaped molded charcoal having a size of 64.5 mm x 25.4 mm x 19.1 mm. The detailed manufacturing process of the remaining briquettes can be easily understood by those skilled in the art, so that detailed description thereof will be omitted.

Experiment to measure compressive strength of briquette

The compressive load of the briquette was measured as the maximum load when compressed at a speed of 50 mm / min and measured as the average value of the 20 molded samples.

Experiment to measure the drop strength of the briquette

The drop strength index of the manufactured briquettes was measured to evaluate the cold quality. The drop strength index was expressed as a weight percentage of a particle size of 20 mm or more after freely falling 2 kg of the manufactured briquettes free from the height of 5 m four times.

Experiments on the measurement of hot strength of briquette

1,000 g of a sample of a normal-temperature shaped carbon sample was charged into a reaction tube having a rotating diameter of 280 mm maintained at 1000 캜, and the reaction was carried out at a rotation speed of 10 rpm for 60 minutes. At this time, inactive nitrogen is used as the reaction gas, and the temperature of the reaction tube is maintained at 1000 占 폚 during the reaction. The char produced after the reaction was analyzed by particle size analysis and expressed as a percentage of the weight of 10 mm or more on the basis of the weight of the gypsum blanks and expressed as the hot strength index of the blanks.

Experimental Example 1

100 parts by weight of pulverized coal and 0.51 part by weight of HEMC powder having an average particle size of 78 占 퐉 and a viscosity of 28,000 cp were first mixed and then 7 parts by weight of a PVA aqueous solution having a concentration of 7 wt% was added and mixed to prepare a blast furnace. The briquettes were stored at 80 ° C for 24 hours and then their strength was measured.

Experimental Example 2

100 parts by weight of pulverized coal and 0.44 part by weight of HEMC powder having an average particle size of 78 占 퐉 and a viscosity of 28,000 cp were first mixed and then added with 7 parts by weight of a PVA aqueous solution having a concentration of 8 wt% The briquettes were stored at 80 ° C for 24 hours and then their strength was measured.

Experimental Example 3

100 parts by weight of pulverized coal and 0.37 parts by weight of HEMC powder having an average particle size of 78 占 퐉 and a viscosity of 28,000 cp were first mixed and then 7 parts by weight of a PVA aqueous solution having a concentration of 9% by weight was added and mixed. The briquettes were stored at 80 ° C for 24 hours and then their strength was measured.

Comparative Example 1

100 parts by weight of pulverized coal and 1 part by weight of HEMC powder having an average particle size of 78 占 퐉 and a viscosity of 28,000 cp were first mixed and then added with 7 parts by weight of water to prepare a blended coal. The briquettes were stored at 80 ° C for 24 hours and then their strength was measured.

Comparative Example 2

100 parts by weight of pulverized coal and 10 parts by weight of a PVA aqueous solution having a concentration of 10 parts by weight were added and mixed to prepare a molded coal. The briquettes were stored at 80 ° C for 24 hours and then their strength was measured.

Comparative Example 3

100 parts by weight of pulverized coal was mixed with 1 part by weight of PVA in powder form and mixed with 7 parts by weight of water to prepare molded coal. The briquettes were stored at 80 ° C for 24 hours and then their strength was measured.

Comparative Example 4

PVA aqueous solution having a concentration of 12 wt% was tried to be added to 100 parts by weight of pulverized coal, but it was not dissolved well and viscosity was too high, so that uniform stirring was impossible.

Comparative Example 5

10 parts by weight of an aqueous solution containing 6 wt% of PVA and 4 wt% of HEMC was added to 100 parts by weight of the pulverized coal, but it was not dissolved well and the viscosity was too high to uniformly stir.

Experiment result

The compression strength, drop strength and hot strength of the molded bellows produced according to the above-described Experimental Examples 1 to 3 and Comparative Examples 1 to 3 were measured. The results are shown in Table 1 below.

Experimental Example Formulation amount (parts by weight) Briquette Pulverized coal HEMC PVA (solids content) Compressive strength
(Kgf) Drop strength (+ 20mm%) Hot Strength
(+ 10mm%) Experimental Example 1 100 0.51 0.49 92.7 89.8 73.6 Experimental Example 2 100 0.44 0.56 87.2 87.8 67.2 Experimental Example 3 100 0.37 0.63 79.2 86.2 63.4 Comparative Example 1 100 One - 93.1 89.2 78.1 Comparative Example 2 100 - One 71.7 92.3 32.4 Comparative Example 3 100 - One 23 32 15.1

As shown in Table 1, it can be confirmed that the molded articles of Examples 1 to 3 have excellent compression strength, drop strength and hot strength. Particularly, it can be confirmed that Experimental Example 1 is superior to Experimental Examples 2 and 3 in terms of hot strength.

In Comparative Example 1 using cellulose ether binder alone, all of the strengths were found to be good, but it is expected to be the largest cost in terms of binder cost, and since only a powdery binder is used, the dissolution time The quality difference between the briquettes due to shortage occurs. Next, in Comparative Example 2 using PVA alone, the compressive strength and the drop strength were excellent but the hot strength was weak. Next, in Comparative Example 3 using PVA in powder form, all of the strengths were found to be weak. In the case of Comparative Example 4 and Comparative Example 5, the test was impossible due to an increase in viscosity.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims. As will be understood by those skilled in the art. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive.

10. Melt gasification furnace 20. Packed bed type reduction furnace
22. Fluidized Bed Type Reduction Furnace
40. Reduction iron compactor 50. Compressed reduction iron storage tank
60: Molded carbon production apparatus 61: Pulverized coal hopper
62: Cellulose ether hopper 63: Melting bath
64: first mixer 65: second mixer
66: Molding machine 67: Storage bin
68: heat source 69: hot air supply pipe
70: blower 71: exhaust line
72: Dust collector 100, 200. Molten iron manufacturing device
101. Dome

Claims

A melter-gasifier furnished with reduced iron, and
A reducing furnace connected to the melter-gasifier and providing the reduced iron;
Wherein the molten iron is charged into a dome of the melting and gasifying furnace and rapidly heated,
Providing pulverized coal,
Mixing the pulverized coal with a powdery cellulose ether compound having an average particle size of 50 mu m to 100 mu m to provide a blended coal,
Preparing an aqueous solution comprising polyvinyl alcohol;
Adding an aqueous solution containing the polyvinyl alcohol to the compounded carbon to provide a mixture; and
And molding the mixture to provide a molded carbon.

The method according to claim 1,
Wherein the amount of the cellulose ether compound relative to 100 parts by weight of the pulverized coal is 0.3 part by weight to 0.7 part by weight.

The method according to claim 1,
The cellulose ether compound is at least one selected from the group consisting of methyl cellulose (MC), hydroxyethyl cellulose (HEC), hydroxypropyl cellulose (HPC), hydroxypropyl methyl cellulose (HPMC) and hydroxyethyl methyl cellulose A method of producing molded-in one kind of compound.

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The method according to claim 1,
Wherein the viscosity of the cellulose ether compound is 4,000 cp to 80,000 cp.

The method according to claim 1,
Wherein the aqueous solution containing polyvinyl alcohol contains 1 wt% to 10 wt% of the polyvinyl alcohol.

The method according to claim 1,
Wherein the polyvinyl alcohol has a weight average molecular weight of 100,000 to 300,000.

The method according to claim 1,
Wherein the polyvinyl alcohol has a viscosity of 28 cp to 47 cp.

The method according to claim 1,
Wherein the step of preparing an aqueous solution containing polyvinyl alcohol comprises dissolving powdery polyvinyl alcohol in water at a temperature of 60 to 100 占 폚.

The method according to claim 1,
Adding an aqueous solution containing polyvinyl alcohol to the blend to provide a blend, wherein 6 to 10 parts by weight of an aqueous solution containing the polyvinyl alcohol is added to 100 parts by weight of the pulverized coal, Way.

The method according to claim 1,
Further comprising the step of drying the mixture before molding the mixture to provide a blast furnace.

The method according to claim 1,
And drying the briquetted carbon after molding the mixture to provide the briquette.

The method according to claim 1,
Wherein the amount of moisture contained in the molded boll is 3 wt% to 13 wt%.

Providing a briquette made according to claim 1,
Providing reduced iron reduced in a reduction furnace; and
Charging the reduced-shaped coal and the reduced iron into a melter-gasifier to provide molten iron
&Lt; / RTI >

15. The method of claim 14,
Wherein the reducing furnace is a fluidized bed type reducing furnace or a packed bed type reducing furnace in the step of providing the reduced iron.

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