WO2008075845A1

WO2008075845A1 - Apparatus for manufacturing compacted irons of reduced materials comprising fine direct reduced irons and apparatus for manufacturing molten irons provided with the same

Info

Publication number: WO2008075845A1
Application number: PCT/KR2007/006325
Authority: WO
Inventors: Il-Hyun Cho; Do-Seung Kim; Myung-Chan Shin
Original assignee: Posco
Priority date: 2006-12-20
Filing date: 2007-12-06
Publication date: 2008-06-26
Also published as: CN101563474B; CN101563474A; KR100797865B1

Abstract

An apparatus for manufacturing compacted iron for manufacturing reduced materials containing fine reduced iron into compacted iron and an apparatus for manufacturing molten iron provided with the same are provided. The apparatus for manufacturing compacted iron includes i) a charging hopper into which reduced materials containing fine reduced iron are charged, and ii) a pair of rollers that form a gap therebetween by being spaced apart from each other and that press the reduced materials containing fine reduced iron that are discharged from the charging hopper and pass through the gap, thereby manufacturing the compacted iron. The above-described charging hopper includes i) a surface of a wall, and ii) an integrated lower surface that is connected to the surface of the wall and is directed toward the pair of rollers. In addition, at least one discharging opening is formed on the integrated lower surface to discharge the reduced materials containing fine reduced iron to the pair of rollers.

Description

APPARATUS FOR MANUFACTURING COMPACTED IRONS OF

REDUCED MATERIALS COMPRISING FINE DIRECT REDUCED

IRONS AND APPARATUS FOR MANUFACTURING MOLTEN IRONS

PROVIDED WITH THE SAME

Technical Field

The present invention relates to an apparatus for manufacturing compacted iron and an apparatus for manufacturing molten iron using the same, and more specifically to an apparatus for manufacturing compacted iron, compacting reduced materials containing direct reduced iron, and manufacturing compacted iron, and an apparatus for manufacturing molten iron that manufactures molten iron using the same. Background Art

Currently, approximately 60% of the world's iron production is produced using a blast furnace method that has been in development since the 14th century. According to the blast furnace method, iron ore that has gone through a sintering process and coke that is produced using bituminous coal as a raw material are charged into a blast furnace together and oxygen is supplied thereto to reduce the iron ore to iron, thereby manufacturing molten iron. The blast furnace method, which is the most popular in plants for manufacturing molten iron, requires that raw materials have strength of at least a predetermined level and have grain sizes that can ensure permeability in the furnace, taking into account reaction characteristics. For that reason, as described above, coke that is obtained by processing specific raw coals is used as a carbon source to be used as a fuel and as a reducing agent. Also, sintered ore that has gone through a successive agglomerating process is mainly used as an iron source.

Accordingly, the modern blast furnace method requires raw material preliminary processing equipment, such as coke manufacturing equipment and sintering equipment. Namely, it is necessary to be equipped with subsidiary facilities in addition to the blast furnace, and to also have equipment for preventing and minimizing pollution generated from the subsidiary facilities. Therefore, there is a problem in that a heavy investment in additional facilities and equipment leads to increased manufacturing costs.

In order to solve these problems with the blast furnace method, significant effort has been made in iron works all over the world to develop a smelting reduction process that produces molten iron by directly using raw coal as a fuel and a reducing agent and by directly using fine ore, which accounts for more than 80% of the world's ore production.

When fine reduced iron that has been converted from fine iron ore is directly charged into a melter-gasifier, the fine reduced iron is not only scattered but also permeability of gas in the melter-gasifier is deteriorated. Therefore, an apparatus for briquetting fine reduced iron and charging it into the melter-gasifier has been developed. That is, an apparatus for manufacturing briquettes compacts fine reduced iron to manufacture reduced materials.

However, a conventional apparatus for manufacturing briquettes cannot handle a large amount of reduced materials containing fine reduced iron. Therefore, when a large amount of reduced materials containing fine reduced irons were charged into a charging hopper, there was a problem in that reduced materials containing fine reduced iron of greater than an accommodation limit are scattered to the outside. Furthermore, as a large amount of reduced materials containing fine reduced irons were charged, permeability of the charging hopper was deteriorated, and thereby gas contained in the reduced materials containing fine reduced irons was difficult to discharge. Because of this, since a pressure variation in the charging hopper occurs, there is a problem in that the fine reduced iron is not uniformly discharged from the charging hopper by influence of a pressure variation. In addition, since a discharging opening for discharging the fine reduced iron, which is independently formed in the charging hopper, is longitudinally protruded toward a lower side, the discharging opening is easily deformed due to heat and pressure.

DISCLOSURE

Technical Problem

An apparatus for manufacturing compacted iron that is capable of handling a large amount of fine reduced iron, discharging gas well, and that is not easily deformed by heat or pressure is provided. In addition, an apparatus for manufacturing molten iron provided with the above-described apparatus for manufacturing compacted iron is provided. Technical Solution

An apparatus for manufacturing compacted iron according to an embodiment of the present invention includes i) a charging hopper into which reduced materials containing fine reduced iron are charged, and ii) a pair of rollers that form a gap therebetween by being spaced apart from each other and press the reduced materials containing fine reduced iron which are discharged from the charging hopper and pass through the gap, thereby manufacturing the compacted iron. The above-described charging hopper includes i) a surface of a wall, and ii) an integrated lower surface that is connected to the surface of the wall and is directed toward the pair of rollers.

At least one discharging opening may be formed on the integrated lower surface to discharge the reduced materials containing fine reduced iron to the pair of rollers. In addition, the at least one discharging opening may include a pair of discharging openings. Also, the discharging opening may be arranged to be symmetrical at left and right sides with respect to a central axis of the charging hopper toward a vertical direction.

Meanwhile, an apparatus for manufacturing compacted iron according to an embodiment of the present invention may further include a screw feeder installed in the charging hopper that may be slanted at an acute angle with a center axis of the charging hopper toward a vertical direction, and that discharges reduced materials containing fine reduced iron that had entered into the charging hopper. Here, a plane including the center axis of trie charging hopper toward a vertical direction and the center axis of the screw feeder may be defined. An angle formed between a center axis of the charging hopper toward a vertical direction and a center axis of the screw feeder may be not greater than an angle formed between the center axis of the screw feeder and the surface of the wall of the charging hopper in the plane.

On the above-described plane, the surface of the wall of the charging hopper may be slanted to make an angle in a range from 15 degrees to 17 degrees, substantially 16 degrees, with respect to the center axis of the screw feeder. In addition, the surface of the wall of the charging hopper may be slanted to make an angle in a range from 22 degrees to 26 degrees, substantially 24 degrees, with respect to the center axis of the charging hopper toward a vertical direction.

Meanwhile, an apparatus for manufacturing compacted iron according to an embodiment of the present invention may further include a party wall installed between the pair of the discharging openings. Here, the party wall may include at least one guiding surface that guides the reduced materials containing fine reduced iron to be discharged through the discharging opening. In addition, at least one guiding surface may be a pair of guiding surfaces. Also, the pair of guiding surfaces may meet to be slanted to each other and form a party wall. The party wall may be located in a manner such that the center axis of the charging hopper toward a vertical direction may cross a line formed when the pair of guiding surfaces meet each other.

Meanwhile, an apparatus for manufacturing molten iron according to an embodiment of the present invention includes i) an apparatus for manufacturing compacted iron provided with the above-described structure, ii) a crusher that crushes the compacted iron that is discharged from the apparatus for manufacturing compacted iron, and iii) a melter-gasifier into which the compacted iron crushed by the crusher is charged. The melter-gasifier may melt the compacted iron. In addition, lumped coal or coal briquettes may be supplied to the melter-gasifier. Advantageous Effects

The apparatus for manufacturing compacted iron according to an embodiment of the present invention has a charging hopper with a large capacity. Therefore, since it has sufficient spare space, gas charged into the charging hopper with the reduced materials containing fine reduced iron and gas generated from the reduced materials containing fine reduced iron are easily discharged. Since the gas is discharged well, discharging pressure of the reduced materials containing fine reduced iron is not rapidly varied.

In addition, since the reduced materials containing fine reduced iron and the gas are separated well by using the spare space, fine particles contained in the reduced materials containing fine reduced iron are not scattered wellwith the gas.

In addition, the surface of the wall of the charging hopper is slanted to make an angle in a range from 22 degrees to 26 degrees with respect to the center axis of the charging hopper toward a vertical direction. Therefore, the reduced materials containing fine reduced iron are not able to stack on an inner side of the surface of the wall while the capacity of the charging hopper can be increased.

In addition, a lower surface of the charging hopper is made to be an integral type, thereby minimizing deformation caused by heat and impact. Therefore, since an operation of the screw feeder can be prevented from being stopped due to a deformation of the discharging opening, and durability of the charging hopper can be improved, manufacturing cost of the molten iron can be reduced due to improved productivity.

In addition, a party wall can be further included in the charging hopper. Therefore, an amount of reduced materials containing fine reduced iron remaining in the charging hopper can be maintained and the reduced materials containing fine reduced iron can be easily discharged through the discharging opening.

Since the apparatus for manufacturing molten iron according to an embodiment of the present invention includes the above-described apparatus for manufacturing compacted iron, molten iron with good quality can be manufactured with a low cost.

In addition, since coal collected from a place of production can be used as lumped coal or coal briquettes, production cost and pollution can be reduced.

DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic perspective view of the apparatus for manufacturing compacted iron according to an embodiment of the present invention.

FIG. 2 is a bottom perspective view of the charging hopper. FIG. 3 is a partial cross-section view along a line III-III of FIG. 1.

FIG. 4 is a concept view illustrating a process for ventilating gas from an inner side of the charging hopper.

FIG. 5 is a schematic cross-sectional view of the charging hopper included in the apparatus for manufacturing compacted iron according to a second embodiment of the present invention.

FIG. 6 is a schematic view illustrating an apparatus for manufacturing molten iron using the apparatus for manufacturing compacted iron according to an embodiment of the present invention.

BEST MODE Exemplary embodiments of the present invention will be explained in detail below with reference to the attached drawings in order for those skilled in the art in the field of the present invention to easily perform the present invention. However, the present invention can be realized in various forms and is not limited to the embodiments explained below. In addition, like reference numerals refer to like elements in the present specification and drawings.

FIG. 1 schematically illustrates an apparatus for manufacturing compacted iron 100 according to an embodiment of the present invention. The apparatus for manufacturing compacted iron 100 includes a charging hopper 10 and a pair of rollers 20. In the apparatus for manufacturing compacted iron 100 shown in FIG. 1, a roll casing 24 is placed therebelow, and a feeding box 30 is installed on an upper side of the roll casing 24 A lower end of the charging hopper 10 is inserted into and combined with a feeding box 30 and is placed thereon.

The reduced materials containing fine reduced iron are charged through an opening 16 of the charging hopper 10 shown in FIG. 1 along a direction indicated by an arrow. The reduced materials containing fine reduced iron are manufactured from iron ore. The reduced materials containing fine reduced iron can further contain additives, and are manufactured while passing through multi-staged fluidized-bed reduction reactors. Reduced materials containing fine reduced iron manufactured by using another method can be charged into the charging hopper 10. A ventilation opening 14, which is formed on an upper side of the charging hopper 10, removes gas charged into the charging hopper 10 with the reduced materials containing fine reduced iron and remaining therein. A screw feeder 12 is installed in the charging hopper to be slanted at an acute angle with a vertical direction. The screw feeder 12 discharges the reduced materials containing fine reduced iron entering into the charging hopper 10 toward the pair of rollers 20 by force. The screw feeder 12 is provided with a screw 122 in an end thereof (shown in FIG. 3). The screw 122 discharges the reduced materials containing fine reduced iron collected in a lower side of the screw feeder 12 downward by rotating a motor (not shown) installed to an upper side of the screw feeder 12. The feeding box 30 pre-compacts the reduced materials containing fine reduced iron discharged to the lower side of the charging hopper 10. In addition, the feeding box 30 uniformly distributes the reduced materials containing fine reduced iron along a longitudinal direction (Y-axis direction) of the pair of rollers 20. The pair of rollers 20 located in the roll casing 24 compact the reduced materials containing fine reduced iron discharged from the charging hopper 10 to manufacture compacted iron. The pair of rollers 20 are spaced apart from each other and form a gap therebetween. The reduced materials containing fine reduced iron enter into the gap and are compacted by the pair of rollers 20 that rotate in opposite directions to each other. The compacted iron is manufactured by using the above method. A roll cover 26 is attached to an outer side of the pair of rollers 20.

In an embodiment of the present invention, the charging hopper 10 has a space capable of accommodating a large amount of the reduced materials containing fine reduced iron. A structure of the charging hopper 10 will be explained in detail below with reference to FIG. 2.

FIG. 2 illustrates an upside-down charging hopper 10 of FIG. 1. An integrated lower surface 104 of the charging hopper 10 is illustrated in an upper side of FIG. 2 for convenient explanation.

The charging hopper 10 includes a surface of a wall 102 and an integrated lower surface 104. The surface of the wall 102 forms a side of the charging hopper 10. The integrated lower surface 104 is connected to the surface of the wall 102 of the charging hopper 10 and is located below the charging hopper 10. The integrated lower surface 104 is formed to be directed toward the above-described pair of rollers 20 (shown in FIG. 1, the same hereinafter). The integrated lower surface 104, as an example, can be manufactured by bending a metal plate. On the contrary, after two metal plates are made to be slanted to each other, they can be welded to be combined with each other or be combined by screws, thereby manufacturing the integrated lower surface 104.

Since a lower surface of a conventional charging hopper is divided into two pieces, thermal shock is imparted thereto by the hot reduced materials containing fine reduced iron. Therefore, it is thermally deformed. In addition, since the lower surface thereof is divided, it does not have sufficient space to accommodate a large amount of reduced materials containing fine reduced iron. On the contrary, since the integrated lower surface 104 shown in FIG. 2 is integrally formed, it can uniformly distribute and contain the thermal shock caused by the reduced materials containing fine reduced iron. Therefore, thermal deformation caused by the hot reduced materials containing fine reduced iron can be reduced. Furthermore, since a large space can be secured in the charging hopper 10 due to the integrated lower surface 104, it is suitable to contain a large amount of the reduced materials containing fine reduced iron. The discharging opening 106 is formed in the integrated lower surface 104.

The discharging opening 106 discharges the reduced materials containing fine reduced iron to the pair of rollers 20. In an embodiment of the present invention, as shown in FIG.2, a pair of discharging openings 106 are formed. The number of the discharging openings can be varied. The discharging openings 106 are arranged to be substantially symmetrical at left and right sides with respect to a center axis CA of the charging hopper 10 toward a vertical direction (shown in FIG. 3, the same hereinafter). That is, the pair of discharging openings 106 can be arranged to be symmetrical at left and right sides, or in a similar manner. When the pair of discharging openings 106 are arranged to be symmetrical to be each other with respect to the center axis CA toward a vertical direction, the reduced materials containing fine reduced iron can be uniformly supplied to the pair of rollers 20 located below the discharging opening 106.

FIG. 3 illustrates a cross-sectional structure cutting along a line III-III of FIG. 1. As shown in FIG. 3, assuming that the center axis CA toward a vertical direction and a center axis SA of the screw feeder 12 are located in the same plane, first, second, and third angles α, β, and γ can be defined as follows. The angle α represents an angle formed between the center axis CA toward a vertical direction and the center axis SA. Also, the angle β represents an angle formed between the center axis SA and the surface of the wall 102. In addition, the third angle γ represents an angle of a sum of the first and second angles α and β. Here, the first angle α is equal to or less than the second angle β. Since the reduced materials containing fine reduced iron charged into the charging hopper 10 should be smoothly discharged to the lower side thereof, it is preferable to arrange the screw feeder 12 to be near the vertical direction. Therefore, the first angle α is preferably small. In addition, in order for the charging hopper 10 to contain a large amount of the reduced materials containing fine reduced iron, capacity of the charging hopper 10 is preferably increased by maximizing the second angle β. Therefore, the second angle β can be equal to or greater than the first angle α. On the contrary, if the first angle α is greater than the second angle β, it is difficult to discharge the reduced materials containing fine reduced iron well and the capacity of the charging hopper 10 cannot be largely increased. As a result, since gas contained in the reduced materials containing fine reduced iron is difficult to ventilate through the ventilation opening 14 (shown in FIG. 1), discharging pressure of the reduced materials containing fine reduced iron is continuously varied. Therefore, compacted iron with good quality is difficult to manufacture. More specifically, the second angle β can be in a range from 15 degrees to 17 degrees. If the second angle β is less than 15 degrees, a space that is necessary for containing a large amount of the reduced materials containing fine reduced iron or ventilating the gas cannot be sufficiently secured. In addition, if the second angle β is over 17 degrees, since a gradient of the surface of the wall 102 is very small, the reduced materials containing fine reduced iron are stacked at the surface of the wall 102. Therefore, when the second angle β is in a range from 15 degrees to 17 degrees, the gas and the reduced materials containing fine reduced iron can be discharged outside well.

Meanwhile, the third angle γ can be in a range from 22 degrees to 26 degrees. Since the third angle γ is a sum of the first and second angles α and β, if the third angle γ is less than 22 degrees, the second angle β becomes small. Therefore, a space that is necessary for containing a large amount of the reduced materials containing fine reduced iron or ventilating the gas cannot be sufficiently secured. In addition, if the third angle γ is over 26 degrees, the reduced materials containing fine reduced iron are stacked on an inner side of the surface of the wall 102 since the gradient of the surface of the wall becomes small. Therefore, if the third angle γ is in a range from 22 degrees to 26 degrees, the gas and the reduced materials containing fine reduced iron can be discharged outside well.

FIG. 4 illustrates a state in which the reduced materials containing fine reduced iron and the gas are discharged outside from the charging hopper 10. The reduced materials containing fine direct reduced iron DRI are charged from an upper side into the charging hopper 10. In addition, the reduced materials containing fine direct reduced iron DRI is in a hot state due to their reduction, and contain gas. The reduced materials containing fine direct reduced iron DRI and the gas charged into the charging hopper 10 fall through the inner side of the charging hopper 10 while being separated from each other due to their density difference. Then, the separated gas is ventilated to the outside of the charging hopper 10 (shown in FIG. 1) through the ventilation opening 14. The gas generated from the reduced materials containing fine direct reduced iron DRI is ventilated to the outside of the charging hopper 10 through the ventilation opening 14 as well. Since the charging hopper 10 has sufficient inner space, gas can be easily separated from the reduced materials containing fine reduced iron and be removed. Therefore, reduced materials containing fine reduced iron, which are densified well by removing the gas, can be discharged to a lower side of the charging hopper 10. Therefore, compacted iron with a high density can be manufactured. In addition, since the gas is discharged well, a pressure variation in the charging hopper 10, which is caused by the gas that is not discharged out, is not large. Therefore, since a discharging pressure of the reduced materials containing fine reduced iron is uniform, compacted iron with a uniform density can be manufactured.

FIG. 5 illustrates a charging hopper 70 included in an apparatus for manufacturing compacted iron according to a second embodiment of the present invention. Since the charging hopper 70 is the same as the charging hopper 10 of FIG. 2 except a party wall 15, like portions are referred to by like reference numerals and detailed description thereof is omitted. An enlarged circle of FIG. 5 illustrates an operational state of the party wall 15. The party wall 15 includes a pair of guiding surfaces 152. The party wall

15 is installed between the pair of the discharging openings 106. More specifically, the party wall 15 is installed such that a line L formed by the pair of guiding surfaces 152 meet with each other to cross the center axis CA toward a vertical direction. Therefore, an amount of reduced materials containing fine reduced iron charged into the charging hopper 70 is divided into multiple amounts and a respective amount thereof can be discharged through the discharging openings 106, respectively. Therefore, the party wall 15 suitably maintains an amount of the reduced materials containing fine reduced iron in the charging hopper 70 while facilitating the reduced materials containing fine reduced iron to be discharged.

As illustrated in the enlarged circle of FIG. 5, since the guiding surface 152 is slanted, the reduced materials containing fine reduced iron slide easily on the guiding surface 152 while being guided to the discharging opening 106 to be discharged well. Although not shown in FIG. 5, front and rear surfaces of the party wall 15 are completely blocked by the surface of the wall 102. Therefore, the reduced materials containing fine reduced iron cannot enter into an inner space of the party wall 15. Meanwhile, the charging hopper 70 can be formed in a way that the inner space of the party wall 15 is completely filled.

FIG. 6 illustrates an apparatus for manufacturing molten iron 200 provided with the above-described apparatus for manufacturing compacted iron 100.

The apparatus for manufacturing molten iron 200 includes the apparatus for manufacturing compacted iron 100, a crusher 40, and a melter-gasifier 60. The crusher 40 crushes compacted iron discharged from the apparatus for manufacturing compacted iron 100. The melter-gasifier 60 melts the compacted iron crushed by the crusher 40 charged thereinto. A storage bin 50 temporarily stores compacted iron crushed by the crusher 40. Since structures of the crusher 40 and the melter-gasifier 60 can be easily understood by those skilled in the art, detailed description thereof is omitted.

Coal such as lumped coal or coal briquettes is supplied to the melter- gasifier 60. For example, coal with a grain size of over 8mm collected from a production site can be used as lumped coal. For example,coal with a grain size that is not more than 8mm that is collected from a production site can be pulverized, have binders added thereto, and be molded by a press, thereby being manufactured to be coal briquettes.

After the above-described coal is charged into the melter-gasifier 60, oxygen O₂ is supplied to the melter-gasifier 60 and the compacted iron is melted, and molten iron is discharged through a tap (not shown). Using the above-described method, molten iron with good quality can be manufactured.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

WHAT IS CALIMED IS

1. An apparatus for manufacturing compacted iron, the apparatus comprising: a charging hopper into which reduced materials containing fine reduced iron are charged; and a pair of rollers that form a gap therebetween by being spaced apart from each other and press the reduced materials containing fine reduced iron that are discharged from the charging hopper and pass through the gap, thereby manufacturing the compacted iron, wherein the charging hopper comprises a surface of a wall, and an integrated lower surface that is connected to the surface of the wall and is directed toward the pair of rollers, wherein at least one discharging opening is formed on the integrated lower surface to discharge the reduced materials containing fine reduced iron to the pair of rollers.

2. The apparatus of Claim 1, wherein the at least one discharging opening comprises a pair of discharging openings.

3. The apparatus of Claim 2, wherein the discharging opening is arranged to be symmetrical at left and right sides with respect to a central axis of the charging hopper toward a vertical direction.

4. The apparatus of Claim 1 further comprising a screw feeder installed in the charging hopper, that is slanted at an acute angle with a center axis of the charging hopper toward a vertical direction, and that discharges reduced materials containing fine reduced iron that has entered into the charging hopper.

5. The apparatus of Claim 4, wherein an angle formed between a center axis of the charging hopper toward a vertical direction and a center axis of the screw feeder is not greater than an angle formed between the center axis of the screw feeder and the surface of the wall of the charging hopper in a plane comprising the center axis of the charging hopper toward a vertical direction and the center axis of the screw feeder.

6. The apparatus of Claim 5, wherein the surface of the wall of the charging hopper is slanted to make an angle in a range from 15 degrees to 17 degrees with respect to the center axis of the screw feeder.

7. The apparatus of Claim 6, wherein the surface of the wall of the charging hopper is slanted to make an angle of 16 degrees with respect to the center axis of the screw feeder.

8. The apparatus of Claim 5, wherein the surface of the wall of the charging hopper is slanted to make an angle in a range from 22 degrees to 26 degrees with respect to the center axis of the charging hopper toward a vertical direction.

9. The apparatus of Claim 8, wherein the surface of the wall of the charging hopper is slanted to make an angle of 24 degrees with respect to the center axis of the charging hopper toward a vertical direction.

10. The apparatus of Claim 2, wherein the charging hopper further comprises a party wall, and wherein the party wall is installed between the pair of discharging openings.

11. The apparatus of Claim 10, wherein the party wall comprises at least one guiding surface that guides the reduced materials containing fine reduced iron to be discharged through the discharging opening.

12. The apparatus of Claim 11, wherein the party wall comprises a pair of guiding surfaces that meet to be slanted to each other, and wherein the center axis of the charging hopper toward a vertical direction crosses a line formed when the pair of guiding surfaces meet each other.

13. An apparatus for manufacturing molten iron, the apparatus comprising: an apparatus for manufacturing compacted iron of Claim 1; a crusher that crushes the compacted iron that is discharged from the apparatus for manufacturing compacted iron; and a melter-gasifier into which the compacted iron crushed by the crusher is charged, the melter-gasifier melting the compacted iron.

14. The apparatus of Claim 13, wherein lumped coal or coal briquettes is supplied to the melter-gasifier.