KR101586743B1 - Manufacturing method of reduced iron and the manufacturing apparatus thereof - Google Patents

Abstract

According to the present invention, a method to manufacture a reduced iron comprises: preparing iron feedstock and coal ash; mixing the iron feedstock and the coal ash; manufacturing coal briquette by molding a mixed material where the iron feedstock and the coal ash are mixed; inserting the coal briquette into a cart at least a part of which is coated with an assistant; performing heat treatment of the coal briquette; and separating the heat-treated reduced iron and the assistant. As such, in accordance to the embodiment of the present invention, the method of the present invention prevents heat loss to the outside of the cart, and prevents or suppresses an increase in temperature by the heat accumulated on a lower part of the cart even though firing is performed at high temperatures. As such, the method of the present invention reduces quality deviation of the reduced iron.

Description

Technical Field [0001] The present invention relates to a reduced iron production method,

The present invention relates to a reduced iron production method and apparatus, and more particularly, to a reduced iron production method and apparatus capable of reducing the quality variation of reduced iron, and a reduced iron produced thereby.

A typical reduced iron manufacturing apparatus includes a plurality of hoppers for receiving iron raw materials and carbonaceous materials, a crusher for receiving and crushing iron raw materials and carbonaceous materials, a mixer for mixing and supplying iron raw materials and carbonaceous materials, And a baking furnace for baking and baking the briquettes produced in the briquetting machine.

On the other hand, in the sintering furnace, reduced iron is produced by heat treatment and reduction. For example, as disclosed in Korean Patent No. 10-1304686, reduced iron charged into a sintering furnace can be placed, dried, preheated, and reduced and fired to produce reduced iron.

During the firing, hot air is supplied from the upper part of the truck loaded with the briquettes, so that the hot air flows from the upper part to the lower part and the heat is accumulated in the lower part, There is a problem in that the quality of the reduced iron produced varies. In some cases, the bogie made of a metal material is melted and causes a problem in operation.

Korean Patent No. 10-1304686

The present invention provides a reduced iron production method and apparatus capable of reducing quality variation, and a reduced iron produced thereby.

The present invention provides a reduced iron production method and apparatus capable of improving the compressive strength and the metallization rate, and a reduced iron produced thereby.

Further, the present invention provides a reduced iron production method and apparatus, and a reduced iron produced by the method, which can prevent the bogie from melting during firing.

A method for manufacturing reduced iron according to an embodiment of the present invention includes the steps of preparing an iron raw material and a carbonaceous material; Mixing the iron raw material and the carbonaceous material; Forming a mixture of the iron raw material and the carbonaceous material to produce a molded carbon; A step of injecting the briquettes into a bogie having at least a portion thereof coated with an auxiliary agent; A step of heat-treating the briquettes; And separating the heat-treated reduced iron and the auxiliary agent.

The bogie may be provided by covering the bottom wall and the inside of the side wall with the auxiliary agent.

The bogie may be provided by coating the inside of the bottom wall with the auxiliary agent and injecting the auxiliary agent into contact with the inner wall of the side wall of the bogie when injecting the briquette.

The adjuvant may comprise a non-magnetic and heat resistant material.

The step of separating the reduced iron and the auxiliary agent may include a step of separating the magnetic substance and the non-magnetic substance using a magnetic force.

The heat treatment may include a step of firing the auxiliary agent.

The method may further include a step of recycling the adjuvant to the reduced iron production process or using the adjuvant in the sintered ores production process.

The adjuvant may comprise a material containing oxygen.

The adjuvant may include at least one of CaCO ₃ , MgCO _3, and Al ₂ O ₃ .

The iron raw material may include at least one of iron ore, iron and steel dust generated in a steel process, and sludge, and the carbonaceous material may include at least one of coal and carbon dust generated in a steel process.

In the reduced iron produced by the reduced iron manufacturing method according to the embodiment of the present invention, the variation of the metallization ratio of the reduced iron located in each area of the bogie may be 10% or less.

The compression strength of the reduced iron located in each area of the bogie may be 150 kgf / p or more.

An apparatus for manufacturing reduced iron according to an embodiment of the present invention includes: a plurality of hoppers containing iron raw materials and carbonaceous materials; A mixer connected to the hopper for feeding and mixing the iron raw material and the carbonaceous material; A molding machine including a compression member for supplying the mixture from the mixer and compressing the molded body; A firing furnace formed to charge the briquettes produced in the molding machine and having a heating member; And a separator having a magnet for separating the reduced iron from the heat-treated fired product.

The burner includes a bottom wall, a sidewall extending upward from the end thereof, and an auxiliary coating layer covering at least a part of the inside of the bottom wall and the sidewall can do.

The adjuvant may be nonmagnetic and may include a material having a melting point higher than the calcining temperature of the calcining furnace.

The thickness of the coating layer may range from 40 to 50 mm.

The firing furnace may include a continuous firing furnace having a drying table, a preheating table, a reducing table, and a cooling table.

According to the embodiments of the present invention, it is possible to prevent the heat loss to the outside of the bogie, even if the firing is carried out at a high temperature, by covering the inside wall of the bogie with an auxiliary agent and heat- Can be effectively prevented or suppressed. From this, since the inside of the bogie is formed at a uniform temperature, the quality deviation of the produced reduced iron can be reduced. That is, high compressive strength and metallization ratio can be obtained in both of the reduced iron produced in the lower region and the upper region of the truck, and the quality deviation can be reduced in each of the upper and lower regions.

Further, since the local temperature rise of the bogie is suppressed by the auxiliary agent, it is possible to suppress or prevent the bogie from being melted or damaged at a high temperature.

In addition, since the reduced iron and the different materials are used as the auxiliary agent, especially the non-magnetic material, after the firing is completed, the reduced iron and the auxiliary agent can be easily separated and the separated auxiliary agent can be recycled.

FIG. 1 is a flowchart showing a method of manufacturing reduced iron according to an embodiment of the present invention
FIG. 2 is a block diagram showing a main part of a reduced iron manufacturing apparatus according to an embodiment of the present invention.
3 is a detailed block diagram showing the firing furnace of FIG. 2 in detail;
Fig. 4 is a detailed conceptual diagram showing in detail the state of a bogie put in the firing furnace of Fig.
Fig. 5 is a conceptual diagram exemplarily showing a process of covering the bogie with the auxiliary agent and charging the briquette.
6 is a graph showing the compressive strengths of reduced iron in Comparative Examples and Experimental Examples
7 is a graph showing the metallization ratios of reduced iron in Comparative Examples and Experimental Examples

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be understood, however, that the invention is not limited to the disclosed embodiments, but is capable of other various forms of implementation, and that these embodiments are provided so that this disclosure will be thorough and complete, It is provided to let you know completely. In the drawings, the size is exaggerated or enlarged in order to clearly illustrate the various elements, and the same reference numerals denote the same elements in the drawings.

FIG. 1 is a flowchart showing a method of manufacturing reduced iron according to an embodiment of the present invention, and FIG. 2 is a block diagram showing a main part of a reduced iron manufacturing apparatus according to an embodiment of the present invention.

Referring to FIG. 1, a method for producing reduced iron according to an embodiment of the present invention includes a step (S100, S200) of preparing iron raw materials and a carbonaceous material, a step (S300) of mixing iron raw materials and carbonaceous materials, (S500, S600), a step of heat-treating the molded carbon (S700), and a step of separating the heat-treated reduced iron and the auxiliary agent from each other (S800).

Here, the iron raw material is a substance containing an iron component, and at least one of iron ore, iron oxide, iron oxide dust and sludge generated during the steelmaking process can be used as a reducing agent. The carbonaceous material is a reducing agent for reducing the iron raw material, and at least one of the coal dust and the carbon dust generated in the steelmaking process can be used. In the examples, a partially reduced iron is produced by a reduced iron production method.

As shown in FIG. 2, the reduced iron manufacturing apparatus for producing reduced iron according to the above process comprises a plurality of hoppers 100 and 200 in which iron raw materials and carbonaceous materials are contained, respectively, and iron raw materials and carbonaceous materials are supplied A molding machine 500 having a compression unit for compressing the mixture mixed in the mixer 400 and a heating member formed to charge the molding blanks manufactured in the molding machine 500 and having a heating member, And a separator 700 for separating the baked material, that is, the baked material, with reduced iron and an auxiliary agent. The crusher 300 is used to crush the iron material and the carbonaceous material, and then the crusher 300 is used to crush the iron material and the carbonaceous material from the hoppers 100 and 200, May be injected.

The molding machine 500 has a compression member (not shown). For example, a molding machine having a pair of rolls provided to face each other, that is, a twin roll molding machine can be used. Thus, when the mixture is charged between the pair of rolls, the blast furnace can be produced by extrusion due to the rotation of the pair of rolls.

The firing furnace 600 is provided with a heating means (not shown) for heating the firing furnace 600, having an internal space, for heating and reducing the briquettes produced in the firing machine 500. The heating means can be a burner and uses LPG and air as the fuel for heating. The heating gas generated by the burner heats the inside of the firing furnace 600, thereby reducing the amount of the briquettes charged into the firing furnace 600 and the carbonaceous material. Of course, various means other than a burner can be used as a means for heating the firing furnace 600, and a raw material of various materials other than fuel, LPG and air can be used.

Also, the firing furnace may have a path through which the bogie storing the briquettes stored therein may be moved, and the temperature may be controlled for each region on the path. 3, the firing furnace 600 may include a drying table 601, a preheating tray 602, a reduction table 603, and a cooling table 604. [ It is of course possible to further include a burner 605 for supplying hot air thereto. From there, a bogie is introduced into the firing furnace 600, and the process of drying, preheating, reducing, cooling, etc. can proceed while the bogie moves continuously through each region of the firing furnace. The briquettes contain a large amount of water after being molded, which is a shape of the bracket or mass, which can cause thermal shocks to be generated if heat is supplied. A bogie stored with the blanket is passed through the drying stand (601) to dry the blanket before firing. The trailer may pass through the preliminary stage 602 and the temperature of the preliminary stage 602 may be adjusted to, for example, 300 to 700 ° C to help reduction after passing through the drying table 601. At this time, the drying band 601 and the preliminary stage 602 can be supplied with a high-temperature gas whose temperature is adjusted to the upper side or the lower side of the bogie. Of course, the high temperature exhaust gas used in the reduction table 603 may be used for the drying table 601 and the preheating table 602. The bogie passing through the preliminary tub 602 continues to the reduction bobbin 603, and the reduced bobbins are produced by the reduction reaction and firing in the reduction bobbin 603. The temperature of the reduction table 603 is preferably 1000 ° C or higher, and when the temperature of the reduction table 603 is less than 1000 ° C, the reduction reaction is not active and the reduction time is long. At the reduction stand 603, hot air at a high temperature is supplied to the upper side of the main truck, and the supplied hot air passes through the molded charcoal to perform the reduction reaction. At the end of the process at the reduction stand 603, the bogie moves to the cooling stand 604 and forms an inert atmosphere by injecting a by-product gas such as COG gas (Coke Ove Gas) to prevent the re- Excellent reduction ratio is obtained. From this, a partially reduced iron having an excellent partial reduction rate can be obtained. Of course, the firing furnace can be changed into a variety of other structures. The bogies will be described later in detail.

The separator 700 includes a magnetic separator having magnets, and separates the reduced iron and the auxiliary agent using a magnet. That is, the separator 700 separates and absorbs the magnetic material, that is, the reduced iron, by applying a magnetic force to the mixed material through the magnet. The structure of separator 700 is sufficient to apply magnetic force, and the structure, method, and shape are not particularly limited.

The reduced iron manufacturing apparatus is not limited to the structure and structure described above, and can be variously changed.

Hereinafter, with reference to Figs. 1 and 2, a method for producing reduced iron will be described in more detail.

First, an iron raw material is prepared (S100), a carbonaceous material to be used as a reducing agent is prepared (S200), and these are stored in the separate hoppers 100 and 200 separately. The iron material and the carbonaceous material stored in the respective hoppers 100 and 200 are crushed by crushing the crusher 300 so that the particle size of the iron material is less than 0.1 mm and the particle size of the carbonaceous material is not more than 1 mm have.

After the crushing of the iron raw material and the carbonaceous material in the crusher 300, the iron raw material and the carbonaceous material are charged into the mixer 400 and mixed (S300). At this time, it is preferable to mix the carbonaceous material so that the carbonaceous material is contained in an amount of 15% by weight or more based on the total weight of the mixture based on the mixture of the iron material and the carbonaceous material. At this time, in addition to the iron raw material and the carbonaceous material, a binder may be further mixed. The binder is chemically bonded between the carbonaceous material and the iron raw material to enhance viscosity and adhesion. In order to exhibit such an effect, the binder may be contained in an amount of 1 to 5% by weight based on the total weight of the binder. As the binder, one of a hydraulic binder and an organic binder may be used. Of course, the mixture may contain inevitable components other than iron raw materials, carbon materials, and binders.

Thereafter, the mixture is charged into the molding machine 500 and molded (S400). For example, the briquettes may be a briquette containing a carbonaceous material.

Meanwhile, a bogie to be charged with the briquette is provided (S500). A bogie is a kind of container which stores the briquetted coal and is injected into the firing furnace, and can be made of a metal material. Referring to FIG. 4, the bogie 610 has an inner space in which the briquettes are stored, and has a bottom wall 612 and side walls 611 extending upward at the end of the bottom wall. At this time, the bogie 610 is covered with the auxiliary agent 20 at least in part. That is, the inner surface of the bottom wall 612 of the bogie 610 or a part or the whole of the inner surface of the side wall 611 can be covered with the auxiliary agent 20 and the whole of the bottom wall 612 and the side wall 611 The inner surface may be covered with the aid 20.

The bogie 610 may form a covering layer of the auxiliary agent 20 in the inside of the bogie before the bogie 10 is loaded or may form the coating layer of the auxiliary agent 20 while charging the bogie 10. For example, an auxiliary agent is injected into the empty truck 610 to form an auxiliary agent coating layer on the inner surface of the bottom wall 612, and auxiliary agents are stacked in the height direction along the inner surface of the side wall 611, Can be formed.

5, an auxiliary agent is injected into the empty truck 610 to form a lower coating layer 20a of an auxiliary agent on the inner surface of the bottom wall 612 (FIG. 5 (a)). Thereafter, the briquettes 10 and the auxiliary agent 20 are charged together (Fig. 5 (b)). At this time, the auxiliary charger 20 is brought into contact with the inner surface of the side wall 611 of the vehicle by adjusting the position of the injected molding 10 and the position where the auxiliary agent 20 is inserted. That is, the briquettes 10 are charged into the central region of the truck 610, and the auxiliary agent 20 is placed adjacent to the inner surface of the side wall 611 of the truck 610. A lateral coating layer 20b is formed on the inner surface of the sidewall 611 of the bogie 610 in contact with an auxiliary agent. The process of simultaneously injecting the briquettes 10 and the auxiliary agent 20 is continued to form the lateral covering layer 20b at a desired height and to load the briquette 10 (FIG. 5 (c)). Of course, only the lower coating layer 20a may be formed at this time.

The auxiliary coating layer may be formed by various other methods. The coating layer may be formed to have a thickness ranging from 40 to 50 mm. In this range, heat loss during heat treatment can be effectively suppressed, and waste of materials can be prevented.

In addition, the coating layer of the auxiliary agent 20 prevents heat loss to the outside of the bogie during reduction or firing of the briquettes 10, increases the thermal insulation property, and reduces the temperature deviation between the upper region and the lower region in the bogie 610 during the heat treatment. That is, by forming the covering layer in the lower wall and the side wall inside the bogie 610, the flow of the hot air flowing in from the upper side is smooth and the accumulation of heat in the lower portion of the bogie is suppressed, Thereby suppressing or preventing the occurrence of a temperature deviation between the center, middle, and edge regions, thereby uniformly distributing the temperature.

At this time, the auxiliary material 20 can be made of a material different from that of the shaped coal 10 in terms of composition or state, and a heat-resistant material having a melting point higher than the firing temperature of the firing furnace 600 can be used. Non-magnetic materials can also be used as adjuvants. Since the non-magnetic substance is used as the auxiliary agent 20, the fired material can be separated into reduced iron and an auxiliary agent using the magnet after the heat treatment is completed. On the other hand, for example, when the reduced iron produced in the previous step is crushed to be used as the auxiliary agent 20 in the subsequent step, it becomes very difficult to separate the reduced iron and the auxiliary agent to be produced, and the auxiliary agent, And the like.

If the auxiliary agent 20 is a nonmagnetic material, it is not particularly limited as long as it is a high melting point material. For example, the auxiliary agent 20 may be a material containing oxygen, and at least one of CaCO ₃ , MgCO ₃ and Al ₂ O ₃ Either one can be used. These materials are commonly used in the steel industry, so they are easy to find and easy to handle.

The auxiliary agent 20 may be particles having a predetermined particle size, and may be spherical or non-spherical. For example, it may be similar to gravel. The average particle diameter of the auxiliary agent 20 may range from 3 to 6 mm.

As described above, when the bogie and the briquette are ready, the briquette 10 is charged into the bogie 610 (S600). The bogie 610 storing the briquettes 10 is charged into the firing furnace 600 and the inside of the firing furnace 600 is heat-treated at a predetermined temperature (S700). From this, a reduction reaction takes place in the carbon-containing molded body to produce reduced iron, more preferably partially reduced iron.

In the firing furnace 600, a reduction process of the briquetting charcoal is performed. In order to induce the reduction of the briquettes, the inside of the firing furnace 600 may be led to a reducing atmosphere and may not be induced. That is, the CO ₂ gas, the CO gas, or the hydrogen (H) gas may be supplied into the calcining furnace 600 to be introduced into the reducing atmosphere, or the atmosphere (or air) A similar natural atmosphere may be used. At this time, in the non-reducing atmosphere, the reduced iron can be oxidized when the oxygen concentration is high, so that the oxygen concentration in the baking furnace 600 can be controlled. For example, the oxygen concentration in the firing furnace 600 can be controlled to be 15% or less so as to prevent the reduced iron from being reoxidized. In order to control the oxygen concentration, an inert gas such as nitrogen (N ₂ ), argon (Ar), or the like may be supplied into the baking furnace 600. Further, the gas generated during the reduced iron production process may be circulated and supplied to the firing furnace.

The firing temperature of the briquette in the firing furnace 600 is preferably 1000 占 폚 or higher and preferably 1100 占 폚 to 1300 占 폚. When the inside of the firing furnace 600 is heat-treated at a temperature of 1000 ° C or higher, self-reaction occurs in the iron raw material and the carbonaceous material inside the briquettes charged into the firing furnace 600, that is, inside the carbonaceous material burying material. Here, the partially reduced iron means that the whole of Fe contained in the iron raw material, that is, 100% is not reduced but partially reduced to less than 100%. Of course, reduced iron reduced to 100% can be produced by controlling the firing time or the heat treatment temperature in the firing furnace 600, but a load may be applied to the firing furnace 600 in order to produce reduced iron having a reduced amount of 100%. On the other hand, for example, when the heat treatment temperature in the calcining furnace 600 is less than 1000 ° C, the reduction reaction between the iron raw material and the carbonaceous material does not actively occur, so that the partially reduced iron production may not be easy or the reduced iron production rate may be lowered.

On the other hand, the auxiliary agent 20 can also be baked during the heat treatment process. That is, the auxiliary agent can be sued at the same time at a high temperature at which the briquette is baked. When a carbonic acid-based compound is used as an auxiliary agent, it can be fired as an oxide by the heat applied to the bogie. For example, CaCO ₃ is calcined as an oxide at a temperature of about 900 ° C. or higher. Therefore, when CaCO ₃ is used as an auxiliary agent, the auxiliary agent is calcined with CaO at the calcination temperature of the calcination furnace.

After the completion of each process including firing in the firing furnace 600, the bogie 610 moves out of the firing furnace 600. The material heat-treated from the bogie 610 is collected, and the reduced iron is separated using the separator 700 (S800). The process of separating the reduced iron and the auxiliary from the heat-treated fired product includes a step of separating the magnetic substance and the non-magnetic substance using a magnetic force. That is, a magnetic force is applied to a mixture of iron-containing reduced magnetic iron and a non-magnetic auxiliary agent to adsorb the reduced iron on the magnets. The separated auxiliary may be recycled as an auxiliary in the reduced iron manufacturing process or used in other processes. At this time, when the auxiliary agent is calcined, the calcined material can be used in various processes requiring the same. For example, CaCO ₃ calcined with CaCO ₃ can be used in the sintering process.

The reduced iron produced in the above-described manner minimizes variation in quality depending on the position of the bogie. That is, since the temperature is uniformly formed inside the bogie, the quality deviation hardly occurs according to the storing position in the bogie. For example, the variation of the metallization ratio of the reduced iron located in each region of the bogie is 10% or less, and the compression strength of the reduced iron located in each bogie region is 150 kgf / p or more.

In the following, reduced iron is manufactured according to whether or not an auxiliary layer is used in a bogie, and various characteristics are evaluated. FIG. 6 is a graph showing the compressive strength of reduced iron in Comparative Examples and Experimental Examples, and FIG. 7 is a graph showing the metallization ratios of reduced iron in Comparative Examples and Experimental Examples.

For the experiment, two blast furnaces manufactured under the same conditions were prepared, one was charged into a bogie which was not coated with an auxiliary agent (Comparative Example), and the other was charged into a bogie having a coating layer of an auxiliary agent in the bottom wall and side walls (Experimental example). At this time, the iron raw material used was a minute iron ore showing a particle size of 0.1 mm or less, and as a carbon material, 20% by weight of coal having a diameter of 1 mm or less was added. These were homogeneously mixed and then made into a carbonaceous built-in briquettes. In addition, agglomerated CaCO ₃ of about 4 to 5 mm was used as an auxiliary agent.

Each bogie was charged into a firing furnace, and firing was carried out while maintaining the firing temperature at 1200 DEG C for 20 minutes. At this time, hot air was supplied from the upper part of the truck to the burner, and the flow of gas was directed downward from the top of the truck. After completion of the calcination, the calcined material was collected and subjected to magnetic separation to obtain reduced iron. At this time, it was confirmed that the auxiliary agent CaCO ₃ was calcined with CaO. Each characteristic was evaluated with the obtained reduced iron.

Referring to FIG. 6, it can be seen that the reduced iron at reduced temperature at room temperature greatly increased in comparison with the case where the auxiliary agent was not used (comparative example). That is, in the case of the experimental example, it can be seen that the bending strength of the briquette placed on the upper part of the bogie and the briquette placed on the lower part is 150 kgf / p or more. Compared with the comparative example, it can be seen that the difference in compressive strength between the reduced iron of the experimental example and the position of the bogie is small.

Referring to FIG. 7, it can be seen that the difference in metallization ratio, that is, the deviation, significantly decreases in the reduced iron in the case where the auxiliary agent is used (the experimental example) in comparison with the case where the auxiliary agent is not used . The rate of metallization is expressed as a percentage of the amount of metal iron with respect to the amount of the total iron content, which is proportional to the reduction rate. In the case of the comparative example, the difference in the metallization ratio of the reduced iron produced according to the position in the car is very large. That is, the reduced iron located in the lower layer of the bogie has a metallization ratio of 56%, but the reduced iron located in the upper layer is 27%, which is greater than 25%. On the other hand, in the case of the experimental example, the difference in the metallization ratio of the reduced iron produced according to the position in the bogie is remarkably reduced. That is, the reduction ratio of the reduced iron located in the lower layer of the bogie is 53%, and that of the reduced iron located in the upper layer is 47%, which is only 6%.

In case of using the auxiliary agent in the bogie, homogeneous quality reduced iron with almost no quality deviation was obtained for each bogie position. In addition, since the non-magnetic material is used as the auxiliary agent, it can be separated from the reduced iron in a very easy and simple manner.

In addition, since reduced iron is produced in a simple manner in a baking furnace, the cost and time of the reduced iron are reduced, and mass production of reduced iron is facilitated.

Although the technical idea of the present invention has been specifically described according to the above embodiments, it should be noted that the above embodiments are for explanation purposes only and not for the purpose of limitation. It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention.

S100: Iron resource preparation S200: Carbonaceous material preparation
S300: Mixture of iron raw material and carbonaceous material S400: Mixture molding
S500: Preparing the car S600: Putting the car in the car
S700: Heat treatment of briquette S800: Reduced iron separation

Claims (18)

Preparing iron raw materials and carbonaceous materials;
Mixing the iron raw material and the carbonaceous material;
Forming a mixture of the iron raw material and the carbonaceous material to produce a molded carbon;
A step of injecting the briquettes into a bogie having at least a portion thereof coated with an auxiliary agent;
A step of heat-treating the briquettes; And
And separating the heat-treated reduced iron and the auxiliary agent. The method according to claim 1,
Wherein the bogie is provided by covering the bottom wall and the inside of the side wall with the auxiliary agent. The method according to claim 1,
Wherein the bogie is coated by coating the interior of the bottom wall with the auxiliary agent and injecting the auxiliary agent into contact with the inner surface of the side wall of the bogie during injection of the briquette. delete delete The method according to claim 1,
Wherein the heat treatment includes firing the auxiliary agent. The method of claim 6,
Further comprising the step of recycling the separated auxiliary agent to a reduced iron production process or using the auxiliary agent in a sintered ores production process. The method according to claim 1,
Wherein the adjuvant comprises a material containing oxygen. The method of claim 8,
Wherein the auxiliary agent comprises at least one of CaCO ₃ , MgCO ₃ and Al ₂ O ₃ . The method according to claim 1,
The iron raw material includes at least one of iron ore, iron-on-steel dust generated in a steel process, and sludge,
Wherein the carbonaceous material comprises at least one of coal and carbon dust generated in a steel process. Claims A reduced iron produced by the production method according to any one of claims 3 to 6. The method of claim 11,
Wherein the variation of the metallization ratio of the reduced iron located in each region of the bogie is not more than 10%. The method of claim 12,
Wherein the reduced iron having the compressive strength of not less than 150 kgf / A plurality of hoppers containing iron material and carbonaceous material;
A mixer connected to the hopper for feeding and mixing the iron raw material and the carbonaceous material;
A molding machine including a compression member for supplying the mixture from the mixer and compressing the molded body;
A firing furnace formed to charge the briquettes produced in the molding machine and having a heating member;
A bogie moving along a path provided inside the firing furnace and having a bottom wall and an auxiliary coating layer covering at least a part of the sidewall extending upward from the end thereof; And
And a separator provided with a magnet for separating reduced iron from the heat-treated fired product. delete 15. The method of claim 14,
Wherein the auxiliary agent is non-magnetic and comprises a material having a melting point higher than the firing temperature of the firing furnace. 18. The method of claim 16,
Wherein the thickness of the coating layer is in the range of 40 to 50 mm. 18. The method of claim 16,
Wherein the firing furnace comprises a continuous firing furnace having a drying table, a preheating table, a reduction table, and a cooling table.

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