KR100711777B1 - Method for manufacturing molten irons improving charging method and apparatus for manufacturing molten irons using the same - Google Patents

Abstract

The present invention relates to a method for manufacturing molten iron with an improved charging method and a molten iron manufacturing apparatus using the same. The method for manufacturing molten iron according to the present invention comprises the steps of converting iron ore from a reducing furnace to a reducing body, preparing a bulk carbonaceous material for forming a coal-filled layer in a molten gasifier connected to the reducing furnace, and reducing and massifying the compacted carbonaceous material into a melt gasification furnace. Pre-mixing from the outside, charging the mixed reducing material and the bulk carbonaceous material into the melt gasifier, injecting oxygen into the coal packed bed to produce molten iron, and reducing gas discharged from the melt gasifier into the reduction furnace Supplying to.

Charge, charge transfer pipe, distribution, melt gasifier

Description

METHOD FOR MANUFACTURING MOLTEN IRONS IMPROVING CHARGING METHOD AND APPARATUS FOR MANUFACTURING MOLTEN IRONS USING THE SAME}

1 is a view schematically showing a molten iron manufacturing apparatus according to a first embodiment of the present invention.

2 is a view schematically showing a molten iron manufacturing apparatus according to a second embodiment of the present invention.

3 is a schematic enlarged view of a portion A of FIGS. 1 and 2.

4A is a loading distribution diagram of a reducing agent according to an experimental example of the present invention.

4B is a loading distribution diagram of a reducing agent according to a comparative example of the prior art.

The present invention relates to a method for manufacturing molten iron with an improved charging method and a molten iron manufacturing apparatus using the same, and more particularly, a molten iron manufacturing method for uniformly distributing charge distribution of a reducing body and a bulk carbonaceous material in a molten gas furnace and a molten iron manufacturing apparatus using the same. It is about.

The steel industry is a core 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 has been with human development. Steel mills, which play a pivotal role in the steel industry, use molten iron and coal as raw materials to produce molten pig iron, which is then manufactured and supplied to each customer.

Currently, about 60% of the world's iron production comes from the blast furnace method developed since the 14th century. Blast furnace method is a method of manufacturing molten iron by reducing the iron ore to iron by putting together the coke prepared from the sintering process and the coke produced from the bituminous coal into the blast furnace. However, the blast furnace method requires a supplementary facility for the production of coke and sintered ore, and there is a serious problem of environmental pollution due to the supplementary facility.

In order to solve the problems of the blast furnace method, many countries around the world are putting a lot of effort into the development of the molten reduction steelmaking method. In the molten reducing steelmaking method, molten iron is produced in a molten gas furnace using direct coal as a fuel and a reducing agent, and ore directly as an iron source. Here, oxygen is blown through a plurality of tuyere provided on the outer wall of the melt gasifier to burn the coal-filled layer in the melt gasifier. The coal filling layer is formed of coal such as lump coal or coal briquettes charged into a melt gasifier. Oxygen blown into the melt gasifier is converted to a high temperature reducing gas and sent to a reduction furnace to reduce iron ore and discharged to the outside. The reduced iron reduced in the reduction furnace is produced by molten iron is transferred to the melt gasifier to melt.

When coal and reduced iron are charged into the melt gasifier, coal and reduced iron are introduced through different charging holes. Therefore, in order to control the load distribution, a device capable of adjusting each drop position is required. Therefore, coal has adjusted the drop position through a plurality of coal charging devices, and reduced iron has adjusted the drop position through a plurality of reduced iron charging devices. Therefore, a plurality of coal charging apparatuses and a plurality of reduced iron charging apparatuses are required, so that the apparatus is not only complicated but also difficult to control.

In order for the reduced iron to melt well, there must be sufficient heat exchange between the charges charged into the melt gasifier and the hot reducing gas from the combustion zone at the front end of the tuyere. In order to sufficiently perform heat exchange, it is preferable that coal and reduced iron are uniformly distributed. However, when the coal and the reduced iron is charged using the aforementioned method, there is a problem in that the distribution of coal and reduced iron is not uniform. In other words, even if the above-described method is used, there is a problem that the distribution of coal and reduced iron is not uniform.

The present invention is to solve the above-mentioned problems, to provide a molten iron manufacturing method and even a molten iron manufacturing apparatus using the same to distribute the loading of the reducing body and the bulk carbonaceous material in the molten gasifier.

In addition, the present invention is to provide a molten iron manufacturing apparatus using the above-described molten iron manufacturing method.

The method for manufacturing molten iron according to the present invention comprises the steps of converting iron ore into a reducing body in a reducing furnace, preparing a bulk carbonaceous material for forming a coal packed bed in a molten gasifier connected to the reducing furnace, melting the reducing body and the bulking carbonaceous material. Pre-mixing from the outside of the gasifier, charging the mixed reducing material and the bulk carbonaceous material into the molten gasifier, injecting oxygen into the coal packed bed to produce molten iron, and reducing gas discharged from the molten gasifier Supplying to the reduction furnace.

In the step of mixing the reducing body and the bulk carbonaceous material, the mass carbonaceous material is preferably introduced and mixed in the vertical direction.

In the step of mixing the reducing body and the bulk carbonaceous material, the inflow direction of the reducing body is preferably 30 ° to 43 ° with respect to the vertical direction.

In the step of charging the mixed reducing body and the bulk carbon material, the reducing body and the bulk carbon material may be evenly distributed at each point in the melt gasifier.

The apparatus for manufacturing molten iron according to the present invention is a reduction furnace for reducing iron ore and converting it into a reducing body, a molten gasification in which a bulk coal material is charged therein to form a coal filling layer and injecting oxygen, and a reducing body conveying tube for transferring the reducing body. , The bulk carbon material conveying pipe which transfers the bulk carbon material and is connected with the reducing material conveying pipe, the one end is connected with the reducing material conveying pipe and the bulk carbon material conveying pipe, and the other end is charged conveying pipe connected to the melt gasifier, and discharged from the melt gasifier It includes a reducing gas supply pipe for supplying the reducing gas to the flow reduction reactor.

The mass charcoal conveying pipe may extend in the vertical direction.

The reducing body conveying tube and the bulk carbonaceous conveying tube may be connected at an angle of 30 ° to 43 °.

The reducing body conveying tube is connected in a vertical direction with the reducing furnace, and a drop box is preferably installed in the middle of the reducing body conveying tube.

The bulk carbonaceous feed pipe may be connected to extend in the same direction as the charge feed pipe.

The reduction furnace may be a packed bed reduction furnace.

The reduction furnace may be a fluidized bed reduction furnace.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 3. These examples are merely to illustrate the invention, but the invention is not limited thereto.

1 shows a molten iron manufacturing apparatus 100 according to a first embodiment of the present invention. The apparatus for manufacturing molten iron 100 shown in FIG. 1 is merely for illustrating the present invention, but the present invention is not limited thereto. Therefore, the apparatus for manufacturing molten iron 100 may be modified in another form.

The molten iron manufacturing apparatus 100 shown in FIG. 1 includes a reduction furnace 30 and a melt gasification furnace 60. In addition, other devices may be included as needed. In order to reduce the iron ore charge the iron ore into the reduction furnace (30). Iron ore is preferably bulky. If necessary, the subsidiary materials may be mixed. Iron ore is converted into a reducing body in the reduction furnace (30). Reduction furnace 30 is a packed-bed reduction reactor, receives a reducing gas from the molten gasifier 60 to form a packed bed therein. Iron ore passes through a packed bed and is converted into a reducing body.

The bulk carbonaceous material is prepared in order to form a coal filling layer in the melt gasifier 60. The bulk coal material includes lump coal or coal briquettes. Coal briquettes are manufactured by press-molding pulverized coal. In addition, coke may be charged as needed. On the outer wall of the melt gasifier 60, a plurality of air vents 601 are provided to blow oxygen into the melt gas furnace 60.

The reducing body and the bulk carbonaceous material are mixed outside the melt gasifier 60 and charged in the melt gasifier 60. Therefore, the reducing body and the bulk carbonaceous material are uniformly well mixed and distributed in the melt gasifier 60. This uniform distribution allows sufficient heat exchange between the bulk carbon material and the reducing body, thereby efficiently manufacturing molten iron.

The reduced body reduced in the reduction furnace 30 is charged through the upper part of the melt gasifier 60 and melted while passing through the coal filling layer. By forming the combustion zone by the oxygen blown into the melt gasifier 60, the reducing body can be melted to produce molten iron. Hot water outlet is installed in the lower portion of the melt gasifier 60 to discharge molten iron and slag to the outside.

Reducing gas is generated from the coal-filled layer formed inside the melt gasifier (60). The reducing gas discharged from the melt gasifier 60 is supplied to the reduction furnace 30 through a reducing gas supply pipe 70. Therefore, iron ore can be reduced by a reducing gas.

2 shows a molten iron manufacturing apparatus 200 according to a second embodiment of the present invention. Since the molten gasifier 60 shown in FIG. 2 is the same as the molten gasifier shown in FIG. 1, the same reference numerals are used and detailed description thereof will be omitted.

The apparatus for manufacturing molten iron 200 includes one or more flow reduction reactors 20, a melt gasifier 60, a reducing gas supply pipe 70, and a compacted material manufacturing apparatus 40. In addition, the high temperature equalization device 30, 50 for transferring the compacted material manufactured by the compacted material manufacturing apparatus 40 to the melt gasifier 60 may be further included. The lowest high temperature uniform back pressure device 30 can also be used as a reduction furnace. The high temperature uniform pressure-reducing apparatus 50 presses the compacted body manufactured by the compacted body manufacturing apparatus 40 to the molten gasifier 60. The compacted material manufacturing apparatus 40 and the high temperature uniform back pressure apparatus 50 can be omitted as needed.

A fluidized bed is formed inside the fluid reduction path 20 to reduce iron ore. The flow reduction path 20 includes a first flow reduction path 201, a second flow reduction path 203, a third flow reduction path 205, and a fourth flow reduction path 207. Although four flow reduction paths 20 are shown in FIG. 1, these are merely to illustrate the present invention and the present invention is not limited thereto. Therefore, three flow reduction reactors may be used.

The first flow reduction path 201 preheats the iron ore with reducing gas discharged from the second flow reduction path 203. The second flow reduction path 203 and the third flow reduction path 205 preliminarily reduce the preheated iron ore. The fourth flow reduction reactor 207 finally converts the preliminarily reduced iron ore into a reducing body. In order to increase the temperature of the reducing gas, each reducing gas supply pipe 70 is provided with an oxygen burner 25.

Iron ore is reduced and heated while passing through the fluid reduction path (20). To this end, the reducing gas generated in the melt gasifier 60 is supplied to the flow reduction path 20 through the reducing gas supply pipe (70). The reduced iron ore is made of compacted material through the compacted material manufacturing apparatus 40.

The compacted material manufacturing apparatus 40 includes the charging hopper 401, a pair of roll 403, the crusher 405, and the storage tank 407. In addition, other devices may be further included as necessary. The charging hopper 401 stores the reduced iron ore while flowing through the flow reduction path 20. Iron ore is press-molded in the form of a strip while being charged from the charging hopper 401 into a pair of rolls 403. The iron ore press-molded in this manner is crushed in the crusher 405 and stored as a compact in the storage tank 407.

In the molten iron manufacturing apparatus 200 according to the second embodiment of the present invention shown in FIG. 2, the reducing body and the bulk carbonaceous material are pre-mixed outside the molten gasifier 60 and charged in the molten gasifier 60. Therefore, it is possible to uniformly mix and distribute the reducing body and the bulk carbonaceous material in the melt gasifier 60. Hereinafter, the transfer method of the pre-mixed charges will be described in more detail with reference to FIG. 3.

3 is an enlarged view of a portion A of FIGS. 1 and 2. A part shown in FIG. 1 and FIG. 2 is a part which charges the charge containing the reducing body and the bulk carbonaceous material to the melting gasifier 60, and is mutually the same. The charging form shown in FIG. 3 is merely for illustrating the present invention and the present invention is not limited thereto. Therefore, the reducing body and the bulk carbonaceous material may be mixed and charged in another way from the outside of the melt gasification furnace 60.

The reduced body reduced in the reduction furnace 30 is charged to the melt gasifier 60 through the reducing body discharge screw 301. The reducing body that has passed through the reduced iron discharge screw 301 is charged into the melt gasifier 60 through the reducing body conveying pipes 305 and 307. The reducing agent conveying tubes 305 and 307 are divided into a first reducing substance conveying tube 305 and a second reducing substance conveying tube 307 with a drop box 303 provided therebetween. The first reducer transfer pipe 305 means a reducer transfer pipe connected in a vertical direction with the reduction furnace 30. Since the first reducing body transfer pipe 305 is installed in the vertical direction, the reducing body can be smoothly transferred. The drop box 303 collides with the free-falling reducing body to reduce the speed of the reducing body. The reducing body which has passed through the second reducing body conveying pipe 307 is mixed with the bulk carbonaceous material.

The bulk carbonaceous material is transferred by the bulk carbonaceous material conveying screw 901, passes through the bulky carbonaceous material conveying pipe 90, and is charged into the melt gasifier 60. Since the mass carbonaceous material conveying pipe 90 extends in the same direction (vertical direction) as the charge material conveying pipe 603, it is easy to load the bulk carbonaceous material. The bulk carbonaceous material conveying tube 90 may be connected to the second reducing material conveying tube 307 to mix the bulk carbonaceous material and the reducing body.

One end (upper end) of the charge feed pipe 603 is connected to the second reducer feed pipe 307 and the bulk carbonaceous material feed pipe 90. Therefore, it is possible to mix the reducing material conveyed through the second reducing material conveying pipe 307 and the bulk carbon material conveyed through the bulk carbonaceous material conveying pipe 90. On the other hand, since the other end (lower end) of the charge feed pipe 603 is connected to the molten gasifier 60, the reducing body and the bulk carbon material can be mixed and charged into the molten gasifier 60. As described above, since the reducing body and the bulk carbonaceous material are mixed in advance and charged into the melt gasifier 60, the reducing body and the bulk carbonaceous material are evenly distributed in the melt gasifier 60.

The other end of the charge transfer pipe 603 is provided with a distributor 605 that can move from side to side in the direction of the arrow, so that the load can be evenly distributed in all directions of the melt gasifier 60.

On the other hand, the inflow direction of the reducing body preferably forms an angle θ of 30 ° to 43 ° with respect to the vertical direction. That is, it is preferable that the 2nd reduction body conveyance tube 307 and the mass carbon material conveyance tube 90 have the above-mentioned angle range. When the angle θ is less than 30 °, the reducing body and the bulk carbonaceous material are hardly mixed. When the angle θ exceeds 43 °, the reducing body is hardly charged.

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.

Experimental Example

The distribution of the charges in the melt gasifier was observed using the same charging device as that shown in FIG. Detailed experimental conditions can be easily understood by those skilled in the art, and the description thereof is omitted.

Fig. 4A shows the distribution of the reducing body in the melt gasifier when the bulk carbon material and the reducing body are premixed and charged. The X axis shows the position of the charge with respect to the center of the melt gasifier, and the Y axis shows the fraction of the reducing agent in the charge according to each position in the melt gasifier.

As shown in Figure 4a, using the charging method according to the invention it can be seen that the reducing body and the bulk carbonaceous material is evenly distributed at each point in the melt gasifier. It can be seen from FIG. 4A that the proportion of the reducing agent in the charge is distributed relatively uniformly at about 55%. Since the reducing body is distributed uniformly, it can be seen that the bulk carbonaceous material is also uniformly distributed at about 45% of the charges. In this way, since the reducing agent and the bulk carbonaceous material are evenly mixed and distributed, the operation of the melt gasification furnace can be stabilized.

Comparative example

For comparison with the present invention, the bulk carbonaceous material and the reducing body were each separately charged into a melt gasifier without being premixed. Experimental conditions for the method of charging the bulk carbon material and the reducing agent separately without pre-mixing can be easily understood by those skilled in the art, and the description thereof will be omitted. Except for mixing, the experimental conditions are the same as the above-described experimental example.

FIG. 4B shows the distribution of the reducing body in the molten gasifier when the bulk carbonaceous material and the reducing body are separately charged into the molten gasifier. As shown in Figure 4b, it can be seen that the reducing body is concentrated about 73% of the charge in the center region of the melt gasifier, and about 10% of the charge is not present at the edge. Therefore, it can be seen that the reducing body and the bulk carbonaceous material are unevenly distributed as a whole.

In the molten iron manufacturing method according to the present invention, the reducing body and the bulk carbonaceous material are premixed and supplied to the molten gasifier. Therefore, since the amount of the loaded carbonaceous material and the reducing body is uniformly distributed over all the points in the molten gasifier, heat exchange is sufficient between the two. As a result, operation can be performed stably without being influenced by the reduction rate and particle size distribution of a reducing body, the hot strength and particle size distribution of a bulk carbonaceous material. Therefore, high quality molten iron can be manufactured efficiently. In addition, there is an advantage that can improve the productivity, reduce the fuel cost and the life of the melt gasification furnace is long.

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

Claims (11)

Converting the iron ore into a reducing body in a reduction furnace, Preparing a bulk carbonaceous material for forming a coal-filled layer in a molten gasifier connected to the reduction furnace; Pre-mixing the reducing body and the mass carbon material outside the molten gasifier; Charging the premixed reducing body and the bulk carbonaceous material into the melt gasifier; Uniformly distributing the premixed reducing body and the bulk carbonaceous material into the molten gasifier; Preparing molten iron by injecting oxygen into the coal-filled layer, and Supplying the reducing gas discharged from the molten gasifier to the reduction furnace Iron manufacturing method comprising a. In claim 1, In the pre-mixing of the reducing body and the mass carbon material, the mass carbon material is introduced in a vertical direction and molten iron manufacturing method. In claim 1, In the step of pre-mixing the reducing body and the bulk carbonaceous material, the reducing body is pre-mixed with the block forming the carbonaceous material 30 ° to 43 °. delete A reduction furnace for reducing iron ore and converting it into a reducing body, A molten gasification furnace in which a lumped carbonaceous material is charged inside to form a coal filling layer and blows oxygen, A reducing tube conveying the reducing body, A bulk carbon material conveying pipe which conveys the bulk carbon material and is connected to the reducing material conveying pipe, One end meets the reducing material conveying tube and the bulk carbonaceous material conveying tube, and the other end is connected to the molten gasifier to supply the charged material mixed with the reducing body and the bulk carbonaceous material to the molten gasifier. , A distributor for evenly distributing the contents into the melt gasification furnace, and Reduction gas supply pipe for supplying the reducing gas discharged from the melt gasifier to the reduction furnace Iron manufacturing apparatus comprising a. In claim 5, The bulk carbon feed pipe is molten iron manufacturing apparatus extending in the vertical direction. In claim 5, The reducing body conveying pipe and the bulk carbonaceous material conveying pipe is a molten iron manufacturing method that meets at an angle of 30 ° to 43 °. In claim 5, The reducing body conveying pipe is connected to the reduction in the vertical direction, the molten iron manufacturing apparatus is provided with a drop box (drop box) in the middle of the reducing body conveying pipe. In claim 5, The bulk carbon material conveying pipe is a molten iron manufacturing apparatus that extends in the same direction as the charge conveying pipe. In claim 5, The reduction furnace is a molten iron manufacturing apparatus is a packed-bed reduction furnace. In claim 5, The reduction furnace is a molten iron manufacturing apparatus is a fluidized bed reduction furnace.

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