FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See section 10, rule 13)
"MOLTEN IRON MANUFACTURING APPARATUS FOR REDUCING EMISSIONS OF CARBON DIOXIDE"
POSCO, of 1, Goedong-dong, Nam-ku, Pohang-shi, Kyungsangbuk-do, 790-300, Republic of Korea;
The following specification particularly describes the invention and the manner in which it is to be performed.

TITLE OF THE INVENTION
APPARATUS FOR MANUFACTURING MOLTEN IRON THAT REDUCES
CARBON DIOXIDE EMISSIONS
CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority to and the benefit of Korean Patent Application No. 10-2010-0004503 filed in the Korean Intellectual Property Office on January 18, 2010, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
(a) Field of the Invention
The present invention relates to an apparatus for manufacturing molten iron. More particularly, the present invention relates to an apparatus for manufacturing molten iron which can reduce an amount of generated carbon dioxide and produce hydrogen, liquid fuel and electrical energy in an iron manufacturing process.
(b) Description of the Related Art
Off- gases generated during an iron manufacturing process are harmful to the environment, and are not preferable in aspects of resource and energy efficiency as recyclable substances are wasted if discharged into the atmosphere as they are.
Further, carbon dioxide contained in off-gases causes climate change, and needs to be retrieved and recycled.

The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art. SUMMARY OF THE INVENTION
The present invention has been made in an effort to provide an apparatus for manufacturing molten iron having advantages of reducing an amount of carbon dioxide generated in an iron manufacturing process by recycling the carbon dioxide.
Further, the present invention has been made in an effort to provide an apparatus for manufacturing molten iron which can produce a liquid fuel and electrical energy in an iron manufacturing process.
An apparatus for manufacturing molten iron according to an exemplary embodiment of the present invention may comprise: a melter-gasifier producing molten iron and generating off-gas; a coke oven producing cokes and generating coke oven gas (COG); a gas mixing device generating a mixed gas by mixing the off-gas and the COG; a mixed gas reforming device generating reducing gas by reforming the mixed gas; and an iron ore reducing device receiving the reducing gas and reducing iron ore by the reducing gas.
In addition, the apparatus for manufacturing molten iron may further comprise off-gas refining facility, and the off-gas refining facility may refine harmful substances in the off-gas and then supply the off-gas to the gas mixing device. The off-gas refining facility may comprise at least one of a cyclone, a filter, and a scrubber. The off-gas refining facility may further comprise a heat

exchanger.
The apparatus for manufacturing molten iron may further comprise a COG refining facility, and the COG refining facility may refine harmful substances in the COG and then supply the refined COG to the gas mixing device. The COG refining facility may comprise at least one of a cyclone, a filter, a scrubber, and an impurity refining reactor. The COG refining facility may further comprise a heat exchanger.
The apparatus for manufacturing molten iron may further comprise a tar reforming reactor, and the tar reforming reactor may be connected to the COG refining facility and reform tar separated from unrefined COG.
The apparatus for manufacturing molten iron may further comprise a heat exchanger, and the heat exchanger may supply heat generated from an melter-gasifier to the mixed gas reforming device.
The apparatus for manufacturing molten iron may further comprise a mixed gas refining facility, the mixed gas refining facility may be provided between the gas mixing device and the mixed gas reforming device, refine the mixed gas, and supply the refined mixed gas to the mixed gas reforming device.
The apparatus for manufacturing molten iron may further comprise a first heat exchanger, the first heat exchanger may supply heat generated from a melter-gasifier to the mixed gas reforming device.
The apparatus for manufacturing molten iron may further comprise a hydrogen separating device and a carbon dioxide regenerating device, the hydrogen separating device may be connected to the mixed gas reforming device to separate hydrogen from the reducing gas, and the carbon dioxide

regenerating device may bring the hydrogen supplied from the hydrogen separating device into reaction with carbon dioxide. In addition, the apparatus for manufacturing molten iron may further comprise a water separating device, and the water separating device may be connected to the carbon dioxide regenerating device to separate and eliminate water generated from the carbon dioxide regenerating device.
The apparatus for manufacturing molten iron may further comprise a liquid fuel generating device, and the liquid fuel generating device may be connected to the mixed gas reforming device to generate a liquid fuel by receiving a reducing gas from the mixed gas reforming device. The liquid fuel generated from the liquid fuel generating device may contain at least one of methanol, dimethyl ether, and a hydrocarbon. The liquid fuel generating device may be a slurry reactor.
In addition, the apparatus for manufacturing molten iron may comprise a second heat exchanger, and the second heat exchanger may supply heat generated from the liquid fuel generating device to the mixed gas reforming device.
The apparatus for manufacturing molten iron may further comprise a compressor, the compressor may be provided between the mixed gas reforming device and the liquid fuel generating device.
The apparatus for manufacturing molten iron may further comprise an electric power generating device, and the electric power generating device may be connected to the liquid fuel generating device and generate electric energy by receiving gas from the liquid fuel generating device. The electric power

generating device may be a turbine.
A mixed gas generated from the gas mixing device may contain hydrogen (H2) and carbon monoxide (CO), and the H2/CO mole ratio may be greater than 0.5 and less than 2.0. The mixed gas may further contain carbon dioxide (C02) and methane (CH4), and the C02/CH4 mole ratio may be greater than 0.7 and less than 4.0.
The apparatus for manufacturing molten iron may further comprise a hydrogen separating device and a carbon dioxide regenerating device, the hydrogen separating device may be connected to the COG refining facility to separate hydrogen from COG, and the carbon dioxide regenerating device may bring hydrogen supplied from the hydrogen separating device into reaction with carbon dioxide. In addition, the apparatus for manufacturing molten iron may further comprise a water separating device, and the water separating device may be connected to the carbon dioxide regenerating device to separate and eliminate water generated from the carbon dioxide regenerating device.
An apparatus for manufacturing molten iron according to another exemplary embodiment of the present invention may comprise: a first iron ore reducing device manufacturing direct reduced iron by reducing iron ore; a melter-gasifier producing molten iron and generating off-gas; a coke oven producing cokes and generating COG; a gas mixing device generating a mixed gas by mixing the off-gas and the COG; a mixed gas reforming device generating reducing gas by reforming the mixed gas; and a second iron ore reducing device receiving the reducing gas and reducing iron ore by the reducing gas.

The apparatus for manufacturing molten iron may further comprise an off-gas refining facility, and the off-gas refining facility may refine harmful substances in the off-gas and then supply the off-gas to the gas mixing device.
The apparatus for manufacturing molten iron may further comprise a COG refining facility, and the COG refining facility may refine harmful substances in the COG and supply the refined COG to the gas mixing device.
The apparatus for manufacturing molten iron may be provided with a gas distributing device between the mixed gas reforming device and the second iron ore reducing device, the gas distributing device may supply a part of reducing gas generated from the mixed gas reforming device to the second iron ore reducing device and supply the rest of the reducing gas to the first iron ore reducing device.
One of the first iron ore reducing device and the second iron ore reducing device may be a fluidized-bed furnace.
According to the present invention, the amount of carbon dioxide generated from the molten iron manufacturing process can be reduced, and the generated carbon dioxide may be recycled.
Further, according to the present invention, hydrogen, a liquid fuel, and electric energy can be produced from the iron manufacturing process. BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of an apparatus for manufacturing molten iron according to a first exemplary embodiment of the present invention.
FIG. 2 is a schematic diagram of an apparatus for manufacturing molten iron according to a second exemplary embodiment of the present invention.

FIG. 3 is a schematic diagram of an apparatus for manufacturing molten iron according to a third exemplary embodiment of the present invention.
FIG. 4 is a schematic diagram of an apparatus for manufacturing molten iron according to a fourth exemplary embodiment of the present invention.
FIG. 5 is a schematic diagram of an apparatus for manufacturing molten iron according to a fifth exemplary embodiment of the present invention.
FIG. 6 is a schematic diagram of an apparatus for manufacturing molten iron according to a sixth exemplary embodiment of the present invention.
FIG. 7 is a schematic diagram of an apparatus for manufacturing molten iron according to a seventh exemplary embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS
The present invention will be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. 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. Accordingly, the drawings and description are to be regarded as illustrative in nature and not restrictive. Like reference numerals designate like elements throughout the specification.
FIG. 1 is a schematic diagram of an apparatus for manufacturing molten iron according to an exemplary embodiment of the present invention.
Referring to FIG. 1, an apparatus for manufacturing molten iron according to the exemplary embodiment of the present invention comprises a melter-gasifier 110, a coke oven 120, a gas mixing device 130, a mixed gas

reforming device 140, an iron ore reducing device 150, an off-gas refining facility 160, a coke oven gas (COG) refining facility 170, a first heat exchanger 180, a vapor separating device 190, and an electric power generating device 195.
The melter-gasifier 110 is a facility that produces molten iron and slag, and generates off-gas by using an iron-containing material and a carbon-containing material. The iron-containing material may be iron ore and the carbon-containing material may be coal.
reduction reactions of the iron-containing material are mostly carried out by using carbon monoxide (CO) and hydrogen (H2) in the melter-gasifier 110, and are represented by Chemical Formulas 1 and 2 as follows.

The H2/CO mole ratio of the off-gas may be more than 0.5 at a temperature of 350 °C or higher.
The off-gas is supplied to the gas mixing device 130 via the off-gas refining facility 160. The off-gas refining facility 160 is installed between the melter-gasifier 110 and the gas mixing device 130, and is a facility for removing harmful substances contained in the off-gas, such as particulates, nitrogen oxides (NOx), sulfur oxides (SOx), and mercury. The off-gas refining facility 160 removes harmful substances by using a cyclone, a filter, or a scrubber. The off-gas refining facility 160 may include a heat exchanger (not shown) for

maintaining heat efficiency of the off-gas. The heat exchanger recovers heat from high-temperature off-gas, and supplies the heat to refined off-gas before the refined off-gas is supplied to the gas mixing device 130. Since the refined off-gas in a high-temperature state flows to the gas mixing device 130, the amount of heat that is additionally supplied to the gas mixing device 130 is reduced. Eventually, the heat efficiency of the entire apparatus for manufacturing molten iron is improved and the amount of generated carbon dioxide can be reduced. The heat exchanger may be provided in combination with at least one of a cyclone, a filter, and a scrubber.
The coke oven 120 produces cokes and generates coke oven gas (COG) at a temperature of over 800 °C. The cokes may be used as a heat source and a reducing agent of the melter-gasifier 110. The COG mostly consists of 58 % hydrogen, 26 % methanol, and 6 % carbon monoxide. The COG may be used as a heat source in iron manufacturing process, or may be used in manufacturing reducing gas, hydrogen, methanol, or direct reduced iron.
The COG is supplied to the gas mixing device 130 through the COG refining facility 170. The COG refining facility 170 is provided between the coke oven 120 and the gas mixing device 130, and eliminates harmful substances included in the COG, such as particulates, sulfur compounds (H2S), ammonia (NH3), BTX, mercury, and the like. Hydrogen may be produced from the refined COG, and the COG component may be continuously used in a later process. The COG refining facility 170 is provided with a cyclone, a filter, a scrubber, or an impurity refining reactor to eliminate harmful substances. The COG refining facility 170 may include a heat exchanger (not shown) to maintain

heat efficiency of the off-gas. In this case, the heat exchanger recovers heat from the high temperature COG, and supplies the heat to the refined COG before the refined COG is supplied to the gas mixing device 130. The heat exchanger may be provided in combination with at least one of a cyclone, a filter, and a scrubber.
The gas mixing device 130 is a device for generating a mixed gas by mixing the off-gas and the COG component. The mixed gas includes hydrogen (H2), carbon monoxide (CO), carbon dioxide (C02), and methane (CH4). The H2/CO mole ratio may be greater than 0.5 and less than 2.0, and the CO2/CH4 mole ratio may be greater than 0.7 and less than 4.0.
The mixed gas may include steam (H2O) and nitrogen (N2). The O/C mole ratio in the mixed gas may be greater than 1.0. This ratio may be controlled by injecting excess carbon dioxide in the off-gas or residual carbon dioxide recovered from the iron manufacturing process into the mixed gas. This ratio may also be controlled by injecting steam or residual steam into the off- gas.
The mixed gas reforming device 140 is a device for generating a reducing gas by reforming the mixed gas. The generated reducing gas includes hydrogen and carbon monoxide. That is, the mixed gas reforming device 140 is a device for bringing methane (CH4) and carbon dioxide into reaction and generating hydrogen (H2) and carbon monoxide (CO), and the reforming reaction is represented by Chemical Formula 3 as follows.
CHA + CO2 → 2CO + 2H2 ...3

C02 + C→2CO ...4 CH4 →C + 2H2 ...5
- ...6
A fluidized-bed reactor may be used as the mixed gas reforming device 140. By using a fluidized-bed reactor, catalyst deactivation due to deposition of carbon can be prevented and yields of produced hydrogen and carbon monoxide can be enhanced.
A first heat exchanger 180 may be provided between the melter-gasifier 110 and the mixed gas reforming device 140. The first heat exchanger 180 supplies heat generated from the melter-gasifier 110 to the mixed gas reforming device 140.
The iron ore reducing device 150 is a unit for receiving the mixed gas from the mixed gas reforming device 140 to reduce iron ore and produce reduced iron. That is, the mixed gas serves as a reducing agent in the iron ore reducing device 150.
The iron ore supplied to the iron ore reducing device 150 may have average particle size smaller than that of the iron ore supplied to the melter-gasifier 110. For example, fine iron ore or ultra-fine iron ore having an average particle size of not more than 1 mm may be supplied to the iron ore reducing device 150.
The iron ore reducing device 150 may be a fluidized-bed reactor which may be operated at a temperature of not less than 700 °C and a pressure of not

less than 1 bar. For example, the fluidized-bed reactor may be a bubbling, turbulent, or riser type. A counter-current type of fluidized-bed reactor where ultra-fine iron ore descends and a reducing synthetic gas rises may be used.
In addition, a sprayed type of fluidized-bed reactor may be used.
An amount of iron in the reduced iron can be regulated or a reduction rate of the reduced iron can be increased by connecting several reactors in parallel or in series to extend a stay time of the iron ore in the reactors.
The reduced iron generated from the iron ore reducing device 150 is provided into a converter or a blast furnace, particularly into an electric furnace, to reduce carbon dioxide from iron and steel making process.
A steam separating device 190 may be connected to the iron ore reducing device 150. The steam separating device 190 can separate and remove the steam generated in an iron ore reducing process, and can also recover heat.
The electric power generating device 195 is connected to the steam separating device 190 to receive the steam and the mixed gas and produce electrical energy. The produced electrical energy may be supplied to each unit constituting the apparatus for manufacturing molten iron. The electric power generating device 195 may be a turbine.
FIG. 2 is a schematic diagram showing an apparatus for manufacturing molten iron according to the second exemplary embodiment of the present invention.
Referring to FIG. 2, the basic elements of the apparatus for manufacturing molten iron according to the second exemplary embodiment of

the present invention are the same as those of the first exemplary embodiment except that the apparatus for manufacturing molten iron according to the second exemplary embodiment further includes a tar reforming reactor 210.
The tar reforming reactor 210 is a device to reform tar generated in a COG refining process. The tar reforming reactor 210 is provided together with the COG refining facility 170. Since tar is reformed in the tar reforming reactor 210, COG flowing into the gas mixing device 130 may be in a state that the content of carbon dioxide and the content of hydrogen are increased.
FIG. 3 is a schematic diagram showing an apparatus for manufacturing molten iron according to the third exemplary embodiment of the present invention.
Referring to FIG. 3, the basic elements of the apparatus for manufacturing molten iron according to the third exemplary embodiment of the present invention are the same as those of the first exemplary embodiment, except that off-gas and COG flow together into a gas mixing device 130 and then flow into a mixed gas reforming device 140 through a mixed gas refining facility 310.
The mixed gas refining facility 310 separates solid particles from the mixture of the COG and the off-gas. The solid particles are iron ore or coal residues, and are separated together with tar residues from the COG. The separated solid particles and tar residues are formed into briquettes or pellets at high temperature and then injected into a blast furnace or a converter, particularly into an electric furnace.
FIG. 4 is a schematic diagram of an apparatus for manufacturing molten

iron according to a fourth exemplary embodiment of the present invention.
Referring to FIG. 4, basic constituent elements of the apparatus for manufacturing molten iron according to the fourth exemplary embodiment of the present invention are similar to those of the apparatus for manufacturing molten iron of the third exemplary embodiment, except that a hydrogen separating device 410, a carbon dioxide regenerating device 420, and a water separating device 430 are additionally provided.
The hydrogen separating device 410 separates hydrogen from a reducing gas generated from the mixed gas reforming device 140 and supplies the separated hydrogen to the carbon dioxide regenerating device 420.
The carbon dioxide regenerating device 420 generates carbon monoxide and steam by bringing the hydrogen supplied from the hydrogen separating device 410 into reaction with carbon dioxide. The reaction can be represented as given in Chemical Equation 7.
H2+C02=H2O+CO .....7
The water separating device 430 is a device for separating and eliminating steam generated from the carbon dioxide regenerating device 420. Subsequently, carbon monoxide is added to the reducing gas and then supplied to the iron ore reducing device 150 so that the reducing cost can be reduced.
FIG. 5 is a schematic diagram of an apparatus for manufacturing molten iron according to a fifth exemplary embodiment of the present invention.
Referring to FIG. 5, basic constituent elements of the apparatus for manufacturing molten iron according to the fifth exemplary embodiment of the

present invention are similar to those of the apparatus for manufacturing molten iron of the third exemplary embodiment, except that a liquid fuel generating device 510 is additionally provided.
The liquid fuel generating device 510 is connected to an iron ore reducing device 150 and generates a liquid fuel by receiving a mixed gas from the iron ore reducing device 150. steam in the mixed gas generated from the iron ore reducing device 150 is separated and eliminated in a steam separating device 190, and residual gas is supplied to the liquid fuel generating device 510. The residual gas may be compressed by a compressor 520 before being supplied to the liquid fuel generating device 510.
The generated liquid fuel may be methanol, dimethyl ether, or any hydrocarbon.
Methanol is generated from a hydrogenation reaction of carbon monoxide (CO), a hydrogenation reaction of carbon dioxide (C02), and a water gas shift reaction. The reactions are respectively represented as given in Chemical Equations 8 to 10.
CO+2H2→CH3OH ....8
co2 + m2 → CH3OH+H2O ...9
CO+H2O ↔ C02+H2 ....10
Dimethyl ether may be generated by methanol, as given in Chemical Equation 11
2CH3OH → CH3OCH3 + H20 .....11

As the liquid fuel generating device 510, a slurry reactor, that is, one of fluidized-bed reactors, is used such that catalyst deactivation due to deposition of carbon can be prevented.
The slurry reactor contains solid-state metallic catalyst and a liquid hydrocarbon wax(high molecular weight liquid) and off-gases containing carbon dioxide, carbon monoxide, and hydrogen, and the off-gases react with the catalyst to produce a liquid fuel such as methanol.
The liquid hydrocarbon wax is a medium for transferring heat and materials, and a second heat exchanger 530 may be installed to retrieve the heat generated through an exothermic reaction. The second heat exchanger 530 is a device for retrieving the heat generated by a liquid fuel producing device 510 and transferring heat to the mixed gas supplied to the mixed gas reforming device 140. Thermal efficiency can be increased by an operation of the second heat exchanger 530.
Meanwhile, the structure of the liquid fuel producing unit 510 is not limited to a slurry reactor, and may include a fixed-bed reactor using off-gas and a catalytic layer.
The liquid fuel such as methanol produced by the liquid fuel generating device 510 and water are separated from each other in a liquid fuel/water separator 540, and the generated mixed gas is supplied to the electric power generating device 195.
FIG. 6 is a schematic diagram of an apparatus for manufacturing molten iron according to a sixth exemplary embodiment of the present invention.
A description of the elements similar to or the same as those of the first

exemplary embodiment among the elements of the apparatus for manufacturing molten iron according to the sixth exemplary embodiment of the present invention will be omitted.
A first iron ore reducing device 610 is a device for manufacturing reduced iron by reducing iron ore. a melter-gasifier 620 receives the reduced iron and produces molten iron.
A gas distributing unit 630 supplies a part of reducing gas generated from a mixed gas reforming device 140 and supplies the rest of the reducing gas to a second iron ore reducing device 640. The first iron ore reducing device 610 or the second iron ore reducing device 640 may be a fluidized-bed reduction furnace.
FIG. 7 is a schematic diagram of an apparatus for manufacturing molten iron according to a seventh exemplary embodiment of the present invention.
A description of the elements similar to or the same as those of the first and fourth exemplary embodiments among the elements of the apparatus for manufacturing molten iron according to the seventh exemplary embodiment of the present invention will be omitted.
A hydrogen separating device 710 separates hydrogen from COG refined in a COG refining facility 170. The separated hydrogen is supplied to a carbon dioxide regenerating device 420.
While this invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent

arrangements included within the spirit and scope of the appended claims.

1. An apparatus for manufacturing molten iron comprising:
a melter-gasifier producing molten iron and generating off-gas;
a coke oven producing cokes and generating coke oven gas (COG);
a gas mixing device generating a mixed gas by mixing the off-gas and the COG;
a mixed gas reforming device generating reducing gas by reforming the mixed gas; and
an iron ore reducing device receiving the reducing gas and reducing iron ore by the reducing gas.
2. The apparatus for manufacturing molten iron of claim 1, further
comprising an off-gas refining facility,
wherein the off-gas refining facility refines harmful substances in the off-gas and then supplies the off-gas to the gas mixing device. .
3. The apparatus for manufacturing molten iron of claim 2, wherein the off-gas refining facility comprises at least one of a cyclone, a filter, and a scrubber.
4. The apparatus for manufacturing molten iron of claim 3, wherein the off-gas refining facility further comprises a heat exchanger.

5. The apparatus for manufacturing molten iron of claim 1, further
comprising a COG refining facility,
wherein the COG refining facility refines harmful substances in the COG and then supplies the refined COG to the gas mixing device.
6. The apparatus for manufacturing molten iron of claim 5, wherein the COG refining facility comprises at least one of a cyclone, a filter, a scrubber, and an impurity refining reactor.
7. The apparatus for manufacturing molten iron of claim 6, wherein the COG refining facility further comprises a heat exchanger.
8. The apparatus for manufacturing molten iron of any one of claim 5 to claim 7, further comprising a tar reforming reactor,
wherein the tar reforming reactor is connected to the COG refining facility and reforms tar separated from unrefined COG.
9. The apparatus for manufacturing molten iron of claim 1, further
comprising a heat exchanger,
wherein the heat exchanger supplies heat generated from a melter-gasifier to the mixed gas reforming device.
10. The apparatus for manufacturing molten iron of claim 1, further
comprising a mixed gas refining facility,

wherein the mixed gas refining facility is provided between the gas mixing device and the mixed gas reforming device, refines the mixed gas, and supplies the refined mixed gas to the mixed gas reforming device.
11. The apparatus for manufacturing molten iron of claim 10, further
comprising a first heat exchanger,
wherein the first heat exchanger supplies heat generated from a melter-gasifier to the mixed gas reforming device.
12. The apparatus for manufacturing molten iron of claim 11, further
comprising a hydrogen separating device and a carbon dioxide regenerating
device,
wherein the hydrogen separating device is connected to the mixed gas reforming device to separate hydrogen from the reducing gas, and
the carbon dioxide regenerating device brings the hydrogen supplied from the hydrogen separating device into reaction with carbon dioxide.
13. The apparatus for manufacturing molten iron of claim 12, further
comprising a water separating device,
wherein the water separating device is connected with the carbon dioxide regenerating device to separate and eliminate water generated from the carbon dioxide regenerating device.
14. The apparatus for manufacturing molten iron of claim 11, further

comprising a liquid fuel generating device,
wherein the liquid fuel generating device is connected to the mixed gas reforming device to generate a liquid fuel by receiving reducing gas from the mixed gas reforming device.
15. The apparatus for manufacturing molten iron of claim 14, wherein the liquid fuel generated from the liquid fuel generating device contains at least one of methanol, dimethyl ether, and a hydrocarbon.
16. The apparatus for manufacturing molten iron of claim 14, wherein the liquid fuel generating device is a slurry reactor.
17. The apparatus for manufacturing molten iron of claim 14, further comprising a second heat exchanger,
wherein the second heat exchanger supplies heat generated from the liquid fuel generating device to the mixed gas reforming device.
18. The apparatus for manufacturing molten iron of claim 14, further
comprising a compressor,
wherein the compressor is provided between the mixed gas reforming device and the liquid fuel generating device.
19. The apparatus for manufacturing molten iron of claim 14, further
comprising an electric power generating device,

wherein the electric power generating device is connected to the liquid fuel generating device and generates electric energy by receiving gas from the liquid fuel generating device.
20. The apparatus for manufacturing molten iron of claim 19, wherein the electric power generating device is a turbine.
21. The apparatus for manufacturing molten iron of claim 1, wherein a mixed gas generated from the gas mixing device contains hydrogen (H2) and carbon monoxide (CO), and the H2/CO mole ratio is greater than 0.5 and less than 2.0.
22. The apparatus for manufacturing molten iron of claim 21, wherein the mixed gas further contains carbon dioxide (CO2) and methane (CH4), and
the CO2/CH4 mole ratio is greater than 0.7 and less than 4.0.
23. The apparatus for manufacturing molten iron of any one of claim
5 to claim 7, further comprising a hydrogen separating device and a carbon
dioxide regenerating device,
wherein the hydrogen separating device is connected to the COG refining facility to separate hydrogen from COG, and
the carbon dioxide regenerating device brings hydrogen supplied from the hydrogen separating device into reaction with carbon dioxide.

24. The apparatus for manufacturing molten iron of claim 23, further
comprising a water separating device,
wherein the water separating device is connected to the carbon dioxide regenerating device to separate and eliminate water generated from the carbon dioxide regenerating device.
25. An apparatus for manufacturing molten iron comprising:
a first iron ore reducing device manufacturing direct reduced iron by reducing iron ore;
a melter-gasifier producing ingot iron and generating off-gas;
a coke oven producing cokes and generating COG;
a gas mixing device generating a mixed gas by mixing the off-gas and the COG;
a mixed gas reforming device generating reducing gas by reforming the mixed gas; and
a second iron ore reducing device receiving the reducing gas and reducing iron ore by the reducing gas.
26. The apparatus for manufacturing molten iron of claim 25, further
comprising an off-gas refining facility,
wherein the off-gas refining facility refines harmful substances in the off-gas and then supplies the off-gas to the gas mixing device.

27. The apparatus for manufacturing molten iron of claim 25, further
comprising a COG refining facility,
wherein the COG refining facility refines harmful substances in the COG and supplies the refined COG to the gas mixing device.
28. The apparatus for manufacturing molten iron of claim 25,
wherein a gas distributing device is provided between the mixed gas reforming
device and the second iron ore reducing device, and
the gas distributing device supplies a part of reducing gas generated from the mixed gas reforming device to the second iron ore reducing device and supplies the rest of the reducing gas to the first iron ore reducing device.
29. The apparatus for manufacturing molten iron of any one of claim
25 to claim 28, wherein one of the first iron ore reducing device and the second
iron ore reducing device is a fluidized-bed furnace.