WO2012091414A2

WO2012091414A2 - Device for manufacturing reduced iron using syngas and method for manufacturing reduced iron using same

Info

Publication number: WO2012091414A2
Application number: PCT/KR2011/010164
Authority: WO
Inventors: 정준양; 최진식; 김성연; 백찬준; 김도형
Original assignee: 주식회사 포스코
Priority date: 2010-12-28
Filing date: 2011-12-27
Publication date: 2012-07-05
Also published as: WO2012091414A3; KR101220683B1; KR20120074645A

Abstract

The present invention relates to a device and a method for manufacturing a high efficiency reduced iron using syngas, and more particularly, provides a device for manufacturing a reduced iron using syngas and a method for manufacturing the reduced iron using same, comprising: at least one fluidized reduction furnace for reacting fine iron ore with a reducing gas to reduce same into the reduced iron; a fine iron ore insertion means, which is connected to the at least one fluidized reduction furnace, for inserting the fine iron ore; a flue gas discharging means for discharging flue gas which is generated in the at least one fluidized reduction furnace; a syngas supplying means for supplying the syngas, which is used as the reducing gas, into the lower portion of a first fluidized reduction furnace; and an agglomerating means for agglomerating the reduced iron which is reduced from the first fluidized reduction furnace.

Description

Reduced iron manufacturing apparatus using syngas and reduced iron manufacturing method using the same

The present invention relates to a method for producing reduced iron through a fluid reduction furnace, and more particularly to an apparatus for producing reduced iron using syngas (Syngas) and a method for producing reduced iron using the same.

The steel industry is a key industry that supplies basic materials to the entire industry, such as automobiles, shipbuilding, home appliances, and construction, and is one of the oldest industries that have been with human development. Steel mills, which play a pivotal role in the steel industry, manufacture molten pig iron, molten iron, using iron ore and coal as raw materials, and then manufacture steel from these and supply it to each customer.

Until now, the blast furnace method was mainly used as a method of manufacturing molten iron. The blast furnace method is a method of manufacturing molten iron by reducing iron ore to iron by putting together iron ore and coke produced through sintering process into a blast furnace and blowing oxygen together. Since the blast furnace method necessarily involves preliminary processing facilities such as coke manufacturing facilities and sintering facilities, it is necessary to establish additional facilities other than blast furnaces, and the production cost is rapidly increased due to the need for installation of anti-contamination prevention facilities by generating large amounts of environmental pollutants. There is a rising problem.

In order to solve the problems of the blast furnace method, much effort has been made to develop a molten iron manufacturing method for manufacturing molten iron by directly using spectroscopy that occupies more than 80% of the world's ore production without the need for raw material preliminary facilities such as sintering. I'm leaning.

The Finex process, which is developed as a kind of the molten reduction steelmaking method, is a flow reduction process for reducing ferrous ore in a flow reduction furnace and a melting process for manufacturing molten iron by melting the directly reduced ferrite ore in a melting furnace. It includes.

1 is a process schematic showing a typical molten iron and steel reduction facility. Referring to FIG. 1, the molten reduction steelmaking facility includes one or more

flow reduction furnaces

20, 30, and 40 for inputting and reducing ferrite ore, agglomeration means 80 and an melting furnace 10 for agglomerating the reduced ferrite ore. Include.

The reduced ferrite (hereinafter reduced iron) reduced through the flow reduction paths (20, 30, 40) is agglomerated via the bulking means (80). This agglomerated reduced iron is called hot briquetted iron (HBI) or hot compacted iron (HCI). The HBI or HCI is used to prepare the molten iron by charging in the melting furnace (10).

In the flow reduction process using the

flow reduction paths

20, 30, 40, reducing gas such as CO and H ₂ is required to reduce iron oxide in the form of ferrite. Up to now, carbon monoxide generated by the combustion of coal in the melting furnace 10 is mainly used.

However, when carbon monoxide in the exhaust gas of the melting furnace 10 is used as the reducing gas of the

flow reduction reactors

20, 30, and 40, since sufficient reducing gas is not contained, the reduction efficiency of the flow reduction furnace is low, and the melting furnace is low. Since a large amount of impurities such as dust generated in (10) is contained, there is a problem of reducing the quality of reduced iron.

One aspect of the present invention is to provide an apparatus for producing reduced iron using a synthesis gas capable of securing reduced iron with high yield and a method for producing reduced iron using the same.

The present invention is one or more flow reduction reactor for reducing the ferrous ore by reducing gas to reduced iron;

Ferrite ore charging means connected to one or more flow reducing paths to load ferrite ore;

Exhaust gas discharge means for discharging the exhaust gas generated in the one or more flow reduction paths;

Syngas supply means capable of supplying the syngas used as the reducing gas to the bottom of the first flow reduction passage; And

Provided is an apparatus for producing reduced iron using a synthesis gas including agglomeration means for agglomerating reduced iron reduced in the first flow reduction reactor.

In addition, the present invention comprises the steps of preparing a synthesis gas;

Charging the syngas into a first flow reduction reactor among the one or more flow reduction reactors to reduce the ferrite ore;

Reducing the ferrite ore in each flow reduction path with reduced iron while the synthesis gas charged in the first flow reduction path sequentially passes through the flow reduction path; And

It provides a method for producing reduced iron using the synthesis gas comprising the step of agglomerated the reduced iron reduced in the first flow reduction reactor.

According to the present invention, instead of using the exhaust gas of the conventional melting furnace, by reducing the ferrite ore by using a synthesis gas (Syngas) containing a large amount of carbon monoxide and hydrogen, it is possible to ensure a high yield of reduced iron, in the exhaust gas Fine ore ores do not need to remove dust, there is an advantage that does not require additional equipment.

1 is a schematic view showing the production of reduced iron using a conventional general fluid reduction reactor.

Figure 2 is a schematic diagram showing the production of reduced iron using the synthesis gas of the present invention.

As the society's rapid growth continued from the 20th century, the energy supply and demand system became unstable, and environmental problems such as global warming have emerged, and environmentally friendly fossil energy has been attempted to produce environmentally friendly fuels. Research on the manufacturing process for doing is also actively underway. In particular, efforts to continuously convert and produce gaseous fuels such as Syngas and Synthetic Natural Gas (SNG) using coal rather than direct combustion of severely polluted coal are continuously used. In addition, ongoing research is being conducted on technologies utilizing the thus produced syngas.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, embodiments of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below. Embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art.

First, the manufacturing apparatus of this invention is demonstrated in detail with reference to FIG. FIG. 2 is for understanding the present invention, and the present invention is not limited by FIG. 2.

The apparatus of the present invention includes one or two or more

flow reduction reactors

20, 30, 40 having a

gas distribution plate

23, 33, 43 loaded therein. At this time, at least one flow reduction path is installed, preferably three flow reduction paths are installed.

The

flow reduction paths

20, 30, and 40 form a fluidized bed with a reducing gas supplied from the bottom to reduce the ferrite ore to be supplied to the next process, and exhaust

gas discharge pipes

21, 31, and 41 to discharge the exhaust gas to the top. Include.

Agglomeration means 80 to agglomerate the reduced iron reduced in the first flow reduction reactor (20). Reduced iron (HBI or HCI) that has been agglomerated through the agglomeration means 80 is charged to the melting furnace (10).

The present invention may include a gasification means 100 to form a syngas (Syngas) as a preferred example. In the gasification means, synthetic gas (Syngas) produced by gasification at high temperature and high pressure using coal, etc. as a raw material is the first flow reduction through the syngas supply means 101 associated with the bottom of the first flow reduction path (20) It is supplied to the furnace 20. The syngas includes reducing gases such as CO and H ₂ .

The syngas is manufactured by incorporating coal, oxygen, and steam into the gasification means 100 and synthesizing at a high temperature and high pressure. The syngas contains at least 40% carbon monoxide (CO) and at least 30% hydrogen gas (H ₂ ), with the remainder containing some carbon dioxide and methane gas.

Before the syngas is supplied to the first flow path 20, it is preferable that a heating means 110 capable of raising the temperature of the syngas is provided. The syngas is heated to a temperature above the reduction temperature of the flow reduction furnace through heating.

Synthesis gas formed by the gasification means 100 includes high purity carbon monoxide (CO) and hydrogen (H ₂ ), it is possible to increase the reduction efficiency in the flow reduction reactor (20, 30, 40), the melting furnace It is possible to obtain a higher reduction efficiency than when using only the exhaust gas generated in (10) alone.

Meanwhile, in the present invention, the synthesis gas and the exhaust gas generated in the melting furnace may be used together. When using the exhaust gas together, it is preferable to include dust removal means for removing the dust before the exhaust gas flows into the flow reduction path.

The number of flow reduction paths is not particularly limited, but FIG. 2 illustrates three flow reduction paths. At this time, the exhaust gas discharged after reduction in the first flow reduction path 20 is again flowed through the first flow reduction path exhaust gas discharge means 21 connected to the bottom of the second flow reduction path 30 in a gas communication relationship. It is transferred to the reduction furnace 30 and is used for the reduction in the second fluid reduction reactor 20.

In addition, the exhaust gas discharged after reduction in the second flow reduction path 30 again flows through the second flow reduction path exhaust gas discharge means 31 connected to the bottom of the third flow reduction path 40 in a gas communication relationship. It is transferred to the reduction furnace 30 and used for reduction in the third flow reduction reactor 40.

Synthetic gas sequentially passed through the first to third flow reduction path is discharged to the exhaust gas purifying device 70 through the third exhaust gas discharge means 41 in the form of exhaust gas in the third flow reduction path (30).

On the other hand, in Figure 2 12 is a reduced iron transfer means connected to the melting

furnace

10, 22, 32 and 42 shows the ferrite ore charging means to the molten reduction furnace (20, 30, 40), 60 is a dust blowing device of the melting furnace Means.

Hereinafter, the method for producing reduced iron of the present invention will be described in detail.

First, a step of preparing a syngas is required. As a preferred example, the syngas may be produced by gasification means. As mentioned above, the syngas contains a large amount of carbon monoxide (CO) and hydrogen (H ₂ ). The synthesis gas is preferably produced by gasification means for producing a synthetic natural gas (SNG, Synthetic Natural Gas).

The syngas is charged into the first flow reduction reactor to reduce the ferrite ore. Before the synthesis gas is charged to the first flow reduction reactor, it is preferable to heat the synthesis gas above the reaction temperature of the first flow reduction reactor. This is to optimize the reduction reaction in the first flow reduction reactor. As an example, when the reduction temperature of the first flow reduction reactor is 780 ° C, the synthesis gas is preferably heated to 820 ° C.

The charged gas flows through the one or more flow reduction paths sequentially, reducing the ferrite ore in each flow reduction path. The reduction reaction in this sequential flow reduction reactor is performed by syngas discharged in the form of flue gas in the previous stage flow reduction reactor. For example, the reduction reaction in the first flow reduction reactor and the discharged exhaust gas contains syngas, which is charged back to the second flow reduction reactor, and the reduction reaction with the ferrite ore in the second flow reduction reactor. This is done.

The reduced iron reduced in the first flow reduction reactor is agglomerated. It is formed to the appropriate size that can be charged into the melting furnace through the agglomeration. The agglomeration is by a conventional process, and is not particularly limited in the present invention. Such agglomerated reduced iron is called hot briquetted iron (HBI) or hot compacted iron (HCI).

Hereinafter, reference numerals of the accompanying drawings will be described.

10 .... Melting Furnace

11 .... Melting Furnace Flue Gas Discharge Means

20, 30, 40 ..... melting reduction furnace

21, 31, 41..Means of exhaust gas discharge

12, 22, 32, 42 ..... ferrite ore charging means

23, 33, 43 ..... Gas Dispersion Plate

50 ..... Melting Furnace Flue Gas Collection Means

51 ..... Melting Furnace Flue Gas Discharge Means

70 ..... Fuel gas treatment means

80 .... Meaning means

100 ..... gasification means

101 ..... Synthetic gas supply means

110 ..... heating means

Claims

At least one flow reduction reactor for reacting the ferrite with reducing gas to reduce iron;

Ferrite ore charging means connected to one or more flow reducing paths to load ferrite ore;

Exhaust gas discharge means for discharging the exhaust gas generated in the one or more flow reduction paths;

Syngas supply means capable of supplying the syngas used as the reducing gas to the bottom of the first flow reduction passage; And

Agglomeration means for agglomerating reduced iron reduced in the first flow reduction reactor

Reduced iron manufacturing apparatus using a synthesis gas comprising a.
The method according to claim 1,

An apparatus for producing reduced iron using syngas, further comprising gasification means for forming the syngas.
The method according to claim 1,

The syngas supply means is a reduced iron manufacturing apparatus using a syngas comprising one or more heating means to be heated before the syngas is supplied to the first flow reduction path.
The method according to claim 1,

Reduced iron manufacturing apparatus using a synthesis gas consisting of three flow reduction path of the reduced iron manufacturing apparatus.
The method according to claim 4,

The exhaust gas discharged from the first flow reduction path is connected in gas communication with the bottom of the second flow reduction path, and the exhaust gas discharged from the second flow reduction path is in gas communication with the bottom of the third flow reduction path. Reduced iron manufacturing apparatus using the syngas connected.
Preparing a syngas;

Charging the syngas into a first flow reduction reactor of at least one flow reduction reactor to reduce the ferrite ore;

Reducing the ferrite ore in each flow reduction path with reduced iron while the synthesis gas charged in the first flow reduction path sequentially passes through the flow reduction path; And

Agglomerating the reduced iron reduced in the first flow reduction reactor

Reduced iron manufacturing method using a synthesis gas comprising a.
The method according to claim 6,

The synthesis gas is reduced iron production method using a synthesis gas comprising the production through a gasification means.
The method according to claim 7,

The syngas is reduced iron production method using the syngas produced by the gasification means for producing a synthetic natural gas (SNG, Sythetic Natural Gas).
The method according to claim 7,

The synthesis gas is reduced iron production method using a synthesis gas containing more than 40% carbon monoxide and more than 30% hydrogen gas.
The method according to claim 6,

The method for producing reduced iron using the synthesis gas further comprises the step of heating the synthesis gas above the reduction temperature of the first induction reduction reactor, before being charged into the first flow reduction reactor.