WO2009078662A2

WO2009078662A2 - Method for manufacturing binderless briquettes and apparatus for manufacturing the same

Info

Publication number: WO2009078662A2
Application number: PCT/KR2008/007469
Authority: WO
Inventors: Woon-Jae Lee; Sang-Han Son; Sung-Man Kim; Il-Hyun Cho; Sang-Ryul Lee
Original assignee: Posco
Priority date: 2007-12-17
Filing date: 2008-12-17
Publication date: 2009-06-25
Also published as: BRPI0821263B8; CN101903541A; WO2009078662A3; BRPI0821263A2; CN101903541B; BRPI0821263B1

Abstract

The present invention relates to a method of manufacturing a binderless briquette and an apparatus for performing the same. The method of manufacturing the binderless briquette includes providing a dust gathered by using a dry collection manner from an offgas discharged when an iron ore is dried, providing a reduced iron ore discharged from an apparatus for manufacturing a molten iron including a reduction furnace providing a reduced iron obtained by reducing the dried iron ore and a melter-gasifier manufacturing the molten iron by melting the reduced iron, providing a sludge discharged from the apparatus for manufacturing the molten iron, providing a mixture formed by drying and mixing at least two sources selected from the group consisting of the dust, the reduced iron ore and the sludge and forming the binderless briquette by molding the mixture without adding a binder.

Description

METHOD FOR MANUFACTURING BINDERLESS BRIQUETTES AND APPARATUS FOR MANUFACTURING THE SAME

Technical Field

[1] The present invention relates to a method for manufacturing a binderless briquette and an apparatus for performing the same. More particularly, the present invention relates to a method for manufacturing a binderless briquette using a dust or a reduced iron that are generated in forming a molten iron and an apparatus for performing the same. Background Art

[2] Various byproducts are generated when a molten iron is manufactured. In case that the byproducts are recycled, a source cost may be largely saved because the byproduct includes carbon or iron. The byproduct may be a dust or a reduced iron ore.

[3] The dust may be recycled in manufacturing a molten iron forming a pellet by using cement as a binder. However, a maturing process is required to the pellet because the cement is used as the binder. In addition, in case that the pellet is used in a blast furnace, a plurality of slag may be generated. Disclosure of Invention Technical Problem

[4] Embodiments of the present invention provide a method for manufacturing a binderless briquette using a dust or a reduced iron that are generated in forming a molten iron.

[5] Embodiments of the present invention provide an apparatus for performing the above method. Technical Solution

[6] In accordance with embodiments of the present invention, a method of manufacturing a binderless briquette is provided. The method includes providing a dust gathered by using a dry collection manner from an offgas discharged when an iron ore is dried, providing a reduced iron ore discharged from an apparatus for manufacturing a molten iron including a reduction furnace providing a reduced iron obtained by reducing the dried iron ore and a melter-gasifier manufacturing the molten iron by melting the reduced iron , providing a sludge discharged from the apparatus for manu- facturing the molten iron, providing a mixture formed by drying and mixing at least two sources selected from the group consisting of the dust, the reduced iron ore and the sludge and forming the binderless briquette by molding the mixture without adding a binder.

[7] In the providing the reduced iron ore, the reduced iron ore is provided after drying and size sorting. The reduced iron ore includes moisture ranging about 10wt% to about 30wt% before the reduced iron ore is dried and size sorted. A reduction rate of the reduced iron ore is about 30% to about 60%. The reduced iron ore is size sorted to be divided into a coarse reduced iron ore and a fine reduced iron ore, and the coarse reduced iron ore is charged into the melter-gasifier. A diameter of the coarse reduced iron ore is over about 8mm.

[8] A molding pressure is about 6t/cm to about lOt/cm when molding the mixture in forming the binderless briquette. The amount of moisture in the reduced iron ore is about 0 to about 6wt% in providing the mixture. The diameter of the reduced iron ore is about lmm to about 5mm in providing the mixture.

[9] The amount of the dust in the mixture is about 0 to about 50wt% in providing the mixture. The reduced iron is provided from the reduction furnace in providing the reduced iron ore. In providing the reduction iron ore, the apparatus for manufacturing the molten iron further comprises a compacted iron forming device connecting the reduction furnace and the melter-gasifier to each other and supplying a compacted iron formed by compacting the reduced iron discharged from the reduction furnace to the melter-gasifier, and the reduced iron ore is supplied from the compacted iron forming device.

[10] In forming the binderless briquette, the strength of the binderless briquette is about

80kgf/p to about 100kgf/p. In providing the sludge, the sludge is provided after the sludge is dried and crushed. The sludge includes about 30wt% to about 40wt% of moisture before the sludge is dried and crushed.

[11] In providing the mixture, the mixture is formed by mixing the dust, the reduced iron ore and the sludge, and the amount of sludge in the mixture is about 0wt% to about 55wt%. The amount of the reduced iron ore is substantially the same as the amount of the dust.

[12] In providing the mixture, the mixture is formed by mixing the dust and the sludge, and the amount of the dust in the mixture is about 70wt% to about 100wt%. In providing the mixture, the mixture is formed by mixing the reduced iron ore and the sludge, and the amount of reduced iron ore in the mixture is above 70wt% to about 100wt%. In providing the mixture, the mixture is thermally treated at a temperature of about 35O⁰C to about 400⁰C.

[13] In accordance with embodiments of the present invention, an apparatus for manufacturing a binderless briquette is provided. The apparatus comprises a dust hopper gathering a dust from an offgas discharged when an iron ore is dried by using a dry collection manner and storing the collected dust, a reduced iron ore hopper storing a reduced iron ore discharged from an apparatus for manufacturing a molten iron including a reduction furnace providing a reduced iron obtained by reducing the dried iron ore and a melter-gasifier manufacturing the molten iron by melting the reduced iron, a sludge hopper storing a sludge discharged from the apparatus for manufacturing the molten iron, a mixture connected to the dust hopper, the reduced iron ore hopper, and the sludge hopper and mixing and heating at least two sources selected from the group consisting of the dust, the reduced iron ore and the sludge to provide a mixture, and a pair of shaping rolls molding the mixture to form the binderless briquette.

[14] The mixer comprises a casing and a rotation member rotating in the casing. The rotation member is a screw-typed member extending in a predetermined direction to be rotated in the casing.

[15] The apparatus further comprises a drier drying the sludge, and a crusher connecting the drier and the sludge to each other and crush the sludge. The drier is a rotary kiln.

[16] The apparatus further comprises a drier drying the reduced iron ore, and a size sorter connecting the drier and the reduced iron ore hopper to each other and size sorting the dried reduced iron ore to divide the dried reduced iron ore into a fine reduced iron ore and a coarse reduced iron ore. The drier is a rotary kiln.

[17] The coarse reduced iron ore is charged into the melter-gasifier. The reduction furnace provides the reduced iron ore hopper with the reduced iron ore.

[18] The mixture is thermally treated at a temperature of about 35O⁰C to about 400⁰C. The apparatus of manufacturing the molten iron further comprises a compacted iron forming device connecting the reduction furnace and the melter-gasifier to each other and he reduced iron ore is supplied from the compacting iron forming device to the reduced iron ore hopper.

[19] The pair of shaping roll molds the mixture at a molding pressure of about 6t/cm to about lOt/cm. The reduction furnace is a fluidized-bed reduction reactor or a packed- bed reactor.

Advantageous Effects

[20] A byproduct (e.g., a dust, a sludge or a reduced iron ore) generated when a molten iron is manufactured may be recycled. Thus, a source cost may be minimized. In addition, a briquette formed by using the dust, the sludge or the reduced iron ore may have a relatively high strength at a high temperature so that the briquette may be effectively charged into a melter-gasifier to manufacture a molten iron. Brief Description of Drawings

[21] FG 1 schematically illustrates an apparatus for manufacturing a binderless briquette in accordance with a first embodiment of the present invention.

[22] FD 2 schematically illustrates an apparatus for manufacturing a binderless briquette in accordance with a second embodiment of the present invention.

[23] FD 3 illustrates an apparatus for manufacturing a molten iron where sources supplied to the apparatuses for manufacturing the binderless briquette in FDSi 1 and 2 are discharged.

[24] FD 4 schematically illustrates an ore drying device from which a dust is discharged.

[25] FD 5 schematically illustrates a fluidized-bed reduction reactor from which a reduced iron ore and sludge are discharged.

[26] FD 6 schematically illustrates a compacted iron forming device from which a reduced iron ore is discharged.

[27] FD 7 schematically illustrates a storage from which sludge is discharged.

[28] FD 8 schematically illustrates an apparatus for manufacturing a molten iron where a reduced iron ore and sludge are discharged.

[29] FDS. 9 to 17 are graphs illustrating variations of compressive strengths of binderless briquettes in according to EXAMPLE 1 to 12. Best Mode for Carrying out the Invention

[30] The invention will be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like reference minerals refer to like elements throughout.

[31] All terms including technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present disclosure, and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[32] A binderless briquette is a briquette formed without adding a binder. Thus, the binder may not be optionally added when forming the briquette.

[33] FG 1 schematically illustrates an apparatus 10 for manufacturing a binderless briquette in accordance with a first embodiment of the present invention.

[34] As illustrated in FD 1, the apparatus for manufacturing the binderless briquette 10 includes a reduced iron ore hopper 101, a dust hopper 102, a mixer 108, and a shaper 110. In addition, the apparatus 10 for manufacturing the binderless briquette may further include a size sorter 105 and storage bins 106 and 107.

[35] The reduced iron ore hopper 101 is provided with a reduced iron ore discharged from a apparatus 1000 (see FD 3) for manufacturing a molten iron. The reduced iron ore is stored in the reduced iron ore hopper 101. The reduced iron ore may be a remet. The reduced iron ore is formed by reducing an iron ore. The reduced iron ore may include a totally reduced iron ore and a partially reduced iron ore.

[36] A reduction rate of the reduced iron ore may be about 30% to about 60%. When the reduction rate of the reduced iron ore is below over about 30% or over about 60%, the binderless briquette may not be effectively formed. In manufacturing the molten iron, the reduced iron ore may be formed when the iron ore is reduced or when a fine direct reduced iron is compacted. The reduced iron ore may be partially recued in manufacturing the molten iron and the recued ore may be then oxidized again when the molten iron is cooled. Thus, the reduced iron may have the above described reduction rate.

[37] The reduced iron ore may be discharged from different parts in the apparatus for manufacturing the molten iron 1000 (see FD 3) Sizes of the reduced iron ores are irregular and the amount of moisture in the recued iron is relatively large because the reduced iron ores are discharged from the different parts and then mixed. Thus, the reduced iron ore may not be directly used as a source for manufacturing the binderless briquette. Thus, the reduced iron ore may be dried and the size of the reduced iron may be sorted before the recued iron is used to manufacture the binderless briquette.

[38] A dust hopper 102 is provided with a dust. The dust is then stored in the dust hopper

102. The dust is formed when the iron ore is dried or when the iron ore is transferred. Particularly, the dust may be gathered from an offgas discharged in drying the iron ore by using a dry collection process. The dust collected by the dry collection process is then supplied to the dust hopper 102. The dust may be supplied to the dust storage bin 107 from the dust hopper 102. The dust is then stored in the dust storage bin 107.

[39] As described above, the reduced iron ore or the dust discharged from the apparatus for manufacturing the molten iron 100 (see FG 3) may be directly used for manufacturing the binderless briquette used in the apparatus for manufacturing the molten iron 1000 so that a source efficiency may be maximized rather than a case where the reduced iron ore or the dust is stacked on a yard.

[40] As illustrated in FD 1, a rotary kiln may be used as a drier 104. Alternatively, other types of drier may be used. The drier 104 may dry the reduced iron ore charged into the drier 104 by using a hot wind. That is, the drier 104 may rotate in an arrow direction and the hot wind is provided inside the drier 104. The reduced iron ore is charged into the drier 104. The reduced ore charged into the drier 104 is dried by the hot wind and then discharged from the drier 104.

[41] A moisture content of the reduced iron ore is adjusted by controlling a temperature of the hot wind. The reduced iron ore may have the moisture content of about 10wt% to about 30wt% before the reduced iron ore is discharged from the apparatus for manufacturing the molten iron 1000 (see FD 3) In case that the moisture content of the reduced iron ore is relatively small, the strength of the briquette is relatively small so that the briquette may be easily broken. On the other hand, in case that the moisture content of the reduced iron ore°l moisture is relatively large, the reduced iron ore may become a slurry shape so that the briquette may not be effectively formed. Thus, the moisture content of the reduce iron ore may be properly adjusted by using the drier 104.

[42] As illustrated in FD 1, the dried reduced iron ore is transferred to the size sorter

105. The size sorter 105 is connected to the drier 104 to sort a size (e.g. a diameter) of the reduced iron ore. The sizes of the molten iron ores discharged from the apparatus 1000 (see FD3) for manufacturing the molten iron are irregular. Thus, the sizes of the reduced iron ores may be adjusted by using the size sorter 105 such that the sizes of th e reduced iron ores become relatively uniform.

[43] The size sorter 105 may sort the dried reduced iron ore as a fine reduced iron ore or a coarse reduced iron ore. For example, the reduced iron ore having a diameter over about 8mm is sorted as a coarse reduced iron ore. The reduced iron ore having a diameter below about 8mm is sorted as a fine reduced iron ore. Here, the coarse reduced iron ore is not suitable for a source of the binderless briquette because the size of the coarse reduced iron ore is relatively large. Thus, the coarse reduced iron ore is directly charged into a melter-gasifier. A structure of the size sorter 105 is well known to a person skilled in the art thus an explanation concerning the structure of the size sorter 105 will be omitted.

[44] As illustrated in FG 1, the fine reduced iron ore is supplied to the reduced iron ore storage bin 106 and the fine reduced iron ore is then stored in the reduced iron ore storage bin 106. The reduced iron ore and the dust may be discharged from the reduced iron ore storage bin 106 and the dust storage bin 107, respectively, and then transferred to the mixer 108.

[45] As illustrated in FD 1, the mixer 108 includes a casing 1081 and a screw-typed member 1083. The screw-typed member 1083 may extend in a predetermined direction in the casing 1081 to be rotated. Thus, the screw-typed member 1083 may mix transfer the reduced iron ore and the dust discharged from the reduced iron ore storage bin 106 and the dust storage bin 107, respectively, toward the shaper 110. The reduced iron ore and the dust may be dried by the mixer 108.

[46] The mixer 108 may achieve a dry function, a mix function, and a transfer function with respect to the reduced iron ore and the dust so that a time required for performing the processes may be largely shortened. The reduced iron ore and the dust may be uniformly mixed in the mixer 108.

[47] As illustrated in FD 1, a mixture obtained by drying and mixing the reduced iron ore and the dust is transferred to the shaper 110. The shaper 110 may include a hopper 1100, a screw 1102 and a pair of shaping rolls 1104. The shaper 110 may further include a hydraulic device (not shown) and a load cell (not shown) installed to the pair of the shaping rolls 1104 to mold the mixture at a relatively constant pressure.

[48] The mixture is charged into the hopper 1100 and the mixture is then temporarily stored in the hopper 1100. The screw 1102 rotates in an arrow direction to forcibly charge the mixture temporarily stored in the hopper 1100 into a gap between the pair of shaping rolls 1104. The pair of the shaping rolls 1104 may rotate in reverse directions. The pair of the shaping rolls 1104 may manufacture the briquette by a cold forming process.

[49] The screw 1102 is installed in the hopper 1100 to forcibly charge the mixture toward the pair of shaping rolls 1104. The mixture is charged into the gap between the pair of shaping rolls 1104. The pair of shaping rolls 1104 rotates to form the briquette. The manufactured binderless briquette is charged again into the melter-gasifier to manufacture the molten iron. The reduced iron ore and the dust may be conϋned with each other due to a reduction degree of the reduced iron ore. Thus, the binderless briquette having a constant compressive strength may be obtained.

[50] FG 2 schematically illustrates an apparatus for manufacturing a binderless briquette in accordance with a second embodiment of the present invention. A structure of the apparatus 12 for manufacturing the binderless briquette in FD 2 is similar to that of the apparatus 10 for manufacturing the binderless briquette in FD 1. Thus, the same reference minerals will be used to designate the same parts and any further explanation will be omitted.

[51] As illustrated in FD 2, the apparatus 12 for manufacturing the binderless briquette includes a sludge hopper 103, a drier 114, a storage bin 108 and a crusher 116. In addition, the apparatus 12 for manufacturing the binderless briquette includes a mixer 109 structurally different from the mixer 108 in FD 1. Another parts included in the apparatus 12 for manufacturing the binderless briquette are substantially the same as those included in the apparatus for manufacturing the binderless briquette 10 in FD 1.

[52] A sludge collected from an offgas discharged from the fluidized-bed reduction reactor 20 (see FD 3) is supplied to the sludge hopper 103. The sludge is then stored in the sludge hopper 103. The sludge may have a reduction rate lower than about 5%. The sludge may include an amount of carbon. The carbon may serve as a lubricant in manufacturing the binderless briquette to decrease strength of the binderless briquette. A portion of the iron ore is changed from hematite into magnetite in the fluidized-bed reduction reactor. A portion of the iron ore is discharged as a form of dust to become a source of the sludge. Thus, the dust included in the sludge may include crack and induce a volune expansion. Thus, a volune density of the sludge is lower than that of the dust.

[53] The sludge includes moisture having a content of about 30wt% to about 40wt% before the sludge is dried and crushed. In case that the sludge include a relatively small amount of moisture, strength of the binderless briquette formed by subsequent processes is too small so that the binderless briquette may be relatively brittle. On the other hand, in case that the sludge includes a relatively large amount of the moisture, the binderless briquette may not be effectively formed. Thus, the amount of moisture in the sludge may be properly adjusted by using the drier 114.

[54] The drier 114 may be a rotary kiln. Alternatively, another drier may be used instead of the rotary kiln. The drier 114 may dry the sludge charged into the drier 114 by using a hot wind. The drier 114 may rotate in an arrow direction. An inside of the drier 114 is provided with the hot wind. A Temperature of the hot wind may be controlled to adjust the amount of moisture in the sludge. The sludge is charged into the drier 114. The sludge charged into the direr 114 is dried by the hot wind and then discharged from the drier 114.

[55] The dried sludge is crushed by the crusher 116. The sludge may be dried to have a lump shape. Thus, the sludge may be required to be crushed by the crusher 116 to have a predetermined diameter suitable for manufacturing the binderless briquette. The crushed sludge is supplied to the sludge storage bin 108 and the crushed sludge is then stored in the sludge storage bin 108.

[56] As described above, the reduced iron ore, the dust or the sludge discharged from the apparatus for manufacturing the molten iron 100 (see FG 3) may be directly used for manufacturing the binderless briquette used in the apparatus for manufacturing the molten iron 1000 so that a source efficiency may be maximized rather than a case where the reduced iron ore, the dust or the sludge is stacked on a yard. The reduced iron ore, the dust and the sludge are discharged from the reduced iron ore storage bin 106, the dust storage bin 107 and the sludge storage bin 108, respectively, and transferred to the mixer 109.

[57] Here, it is not necessary that all of the reduced iron ore, the dust and the sludge are used as sources for manufacturing the binderless briquette. As one example, the reduced iron ore and the dust may be used to manufacture the binderless briquette. As another example, the dust and the sludge may be used to manufacture the binderless briquette. As still another example, the sludge and the reduced iron ore may be used to manufacture the binderless briquette.

[58] As illustrated in FD 2, the mixer 109 includes a casing 1091 and a rotation member

1093. The rotation member 1093 vertically extends in the casing 1091 to be rotated. Thus, the rotation member 1093 may mix and heat the reduced iron ore, the dust and the sludge discharged from the reduced iron ore, the dust and the sludge, respectively. In addition, the rotation member 1093 may transfer the reduced iron ore, the dust and the sludge toward the shaper 110 in mixing and heating the reduced iron ore, the dust and the sludge.

[59] The mixer 109 may achieve a dry function, a mix function, and a transfer function with respect to the reduced iron ore, the dust and the sludge so that a time required for performing the processes may be largely shortened. Here, a mixture may be thermally treated at a temperature of about 35O⁰C to about 400⁰C. In case that the mixture is thermally treated at a temperature of below about 35O⁰C, a binder required to manufacture the briquette may not be sufficiently obtained from the reduced iron ore, the dust and the sludge so that a strength of the briquette is relatively small. In addition, in case that the mixture is thermally treated at a temperature of about 400⁰C, the mixer 109 may be exposed and damaged by the relatively high temperature.

[60] As illustrated in FG 2, the mixture obtained by mixing and heating the reduced iron ore, the dust and the sludge is transferred to the shaper 110. The mixture is charged into the hopper 1100 and then temporarily stored in the hopper 1100. A screw feeder 1102 installed in the hopper 1100 may rotate in an arrow direction and forcibly charge the mixture into a gap between a pair of shaping rolls 1104. The pair of shaping rolls 1104 may rotate in reverse directions. The pair of the shaping rolls 1104 may manufacture the briquette by a cold forming process. Hereinafter, procedures for forming the reduced iron ore, the dust and the sludge that are used as sources of the binderless briquette are illustrated with reference to FDS 3 to 8.

[61] FD 3 illustrates the apparatus 1000 for manufacturing the molten iron where the sources supplied to the apparatus for manufacturing the binderless briquette in FD 1 and the apparatus for manufacturing the binderless briquette in FD 2 are discharged.

[62] As illustrated in FD 3, the apparatus 1000 for manufacturing the molten iron includes a fluidized-bed reduction reactor 20, a compacted iron forming device 30, a melter-gasifier 60, a reduction gas supplying line 70, and an ore drying device 80. In addition, the apparatus 1000 for forming the molten iron may further include a hot pressure equalizing device 40 and a storage 50. The apparatus 1000 for manufacturing the molten iron may further include required devices.

[63] As illustrated in FD 3, the ore drying device 80 may dry the iron ore charged into the fluidized-bed reduction reactor 20. In case that the amount of the moisture in the iron ore is relatively large, the iron ore may not be fluidized in the fluidized-bed reduction reactor 20 and adhere to an inside of the fluidized-bed reduction reactor 20. Thus, an effective fluidization of the iron ore in the fluidized-bed reduction reactor 20 may be obtained by pre-drying the iron ore in the ore drying device 80.

[64] As illustrated in FD 3, the fluidized-bed reduction reactor 20 may include a first fluidized bed 20a, a second fluidized bed 20b, a third fluidized bed 20c and a fourth fluidized bed 2Od. The first fluidized bed 20a, the second fluidized bed 20b, the third fluidized bed 20c and the fourth fluidized bed 2Od are sequentially connected. The fluidized-bed reduction reactor 20 receives a reduction gas from the melter-gasifier 60 through the reduction gas supplying line 70 and reduces the iron ore. The first fluidized bed 20a receives the dried iron ore from the ore drying device 80 and preheats the iron ore by using the reduction gas. The second fluidized bed 20b and the third fluidized bed 20c may pre-reduce the pre-heated iron ore. The fourth fluidized bed 2Od may finally reduce the pre-reduced iron ore to form a fine direct reduced iron.

[65] The fluidized-bed reduction reactor 20 may transfer the fine direct reduced iron to the compacted iron forming device 30. The compacted iron forming device 30 may compact the fine direct reduced iron. In case that the fine direct reduced iron is directly charged into the melter-gasifier 60, the fine direct reduced iron may be outwardly scattered by the reduction gas in the melter-gasifier 60. In addition, the fine direct reduced iron is directly charged into the melter-gasifier 60, an air circulation in the melter-gasifier 60 may be deteriorated. Thus, the fine directed reduced iron is formed as the compacted iron by using the compacted iron forming device 30. The compacted iron is then supplied to the melter-gasifier 60.

[66] As illustrated in FG 3, the compacted iron forming device 30 includes a storage

301, a pair of rolls 302, a crusher 304, and a compacted iron storage 306. The storage 301 may temporarily store the fine direct reduced iron. The fine direct reduced iron may be discharged from the storage 301 and transformed into the compacted iron having a strip shape by the pair of rolls 302. The crusher 304 may crush the compacted iron such that the crushed compacted irons have constant sizes. The crushed compacted iron is stored in the compacted iron storage 306.

[67] The hot pressure equalizing device 40 may connect the compacted iron forming device 30 and the storage 50 to each other. The hot pressure equalizing device 40 may adjust a pressure between the compacted iron forming device 30 and the storage 50 to forcibly transfer the compacted iron from the compacted iron forming device 30 to the storage 50. The storage 50 stores the compacted iron and supplies the compacted iron to the melter-gasifier 60.

[68] The compacted iron is charged into the melter-gasifier 60 and then melted. A lunped carbonaceous material is charged into the melter-gasifier 60 so that a coal-packed bed may be formed inside the melter-gasifier 60. Here, the lunped carbonaceous material may be a lunped coal or a coal briquette. An oxygen gas is injected to the melter- gasifier 60 to burn the coal-packed bed. The compacted iron is melted by a heat obtained by burning the coal-packed bed. The compacted iron is melted to form the molten iron and then the molten iron may be outward discharged. A reduction gas generated from the coal-packed bed is supplied to the fluidized-bed reduction reactor 20 through the reduction gas supplying line 70.

[69] As illustrated in FD 3, the dust is supplied to the apparatus 10 for manufacturing the binderless briquette from the ore drying device 80 through the dust supplying line 90. The offgas discharged from the ore drying device 80 when the iron ore is dried is dry- collected to gather the dust. The dust collected by the above manner is supplied to the apparatus 10 for manufacturing the binderless briquette through the dust supplying line 90. In addition, the reduced iron ore generated from the apparatus 1000 for manufacturing the molten iron is collected and then supplied to the apparatus 10 for manufacturing the binderless briquette through the reduced iron ore supplying line 85. The sludge generated from the apparatus 1000 for manufacturing the molten iron is collected and then supplied to the apparatus 10 for manufacturing the binderless briquette through the sludge supplying line 95. Hereinafter, procedures for discharging the reduced iron ore, the dust and the sludge from the apparatus 1000 for manufacturing the molten iron with reference to FDS 3 to 8.

[70] FD 4 schematically illustrates an ore drying device 80 in FD 3 from which a dust is discharged. A discharging procedure in FD 4 is an example that does not limit the present invention. Thus, the dust may be discharged by another discharging procedure.

[71] As illustrated in FD 4, the ore drying device 80 may include an ore drier 801, a cyclone 804, a back filter 808, a burner 809, etc. The ore drier 801 may be provided with a cokes oven gas (COG) and an air to dry the iron ore. The dried iron ore is transferred from the ore drier 801 to the storage bin 802 and the dried iron ore is stored in the storage bin 802. The iron ore stored in the storage bin 802 is supplied to the fluidized-bed reduction reactor 20(see FD 3)

[72] The offgas discharged from the ore drier 801 is burned by the burner 809. Thus, fine dust ores are burned so that the fine dust ores may be removed. However, the unturned fine dust ores are still included in the offgas and provided into the cyclone 804 together with the offgas. Here, for example, the fine dust ore having a diameter over about 1.5/M may be extracted to a lower portion of the cyclone 804 by the gravity. The extracted fine dust ores is transferred by the first conveyer belt 806 in an arrow direction to be stored in the storage bin 802.

[73] The offgas discharged from the cyclone 804 is transferred to the back filter 808. The dusts included in the offgas that is not collected in the cyclone 804 may be collected in the back filter 808. For example, the dusts may have diameters smaller than about 1.5/M. The dust collected in the back filter 808 may be gathered and then transferred to the apparatus for manufacturing the binderless briquette by a second conveyer belt 807. Thus, the apparatus 10 for manufacturing the binderless briquette may manufacture the briquette by using the dust.

[74] FD 5 schematically illustrates the fluidized-bed reduction reactor 20 in FE 3 from which the reduced iron ore and the sludge are discharged. [75] The reduced iron ore may be provided from the fluidized-bed reduction reactor 20.

The fluidized-bed reduction reactor 20 may reduce the iron ore. In case that the fluidized-bed reduction reactor 20 is repaired, an operation of the fluidized-bed reduction reactor 20 is stopped and the reduced iron ore accunulated in the fluidized- bed reduction reactor 20 may be discharged.

[76] For example, as illustrated in FG 5, the fourth fluidized-bed reduction reactor 2Od may discharge the reduced iron ore by using a wind box located under the fourth fluidized-bed reduction reactor 2Od. The reduced iron ore is stored in a temporal storage 200 and cooled by water. The reduced iron ore is then supplied to the apparatus for manufacturing the binderless briquette though the reduced iron ore supplying line 85.

[77] The offgas is discharged from the first fluidized-bed reduction reactor 20a through the offgas line 22. The offgas includes an amount of dust so that the scrubber 24 is installed at the offgas line 22 and the scrubber 24 injects water to the offgas to remove the dust. The offgas from which the dust is removed is discharged outward or used as the reduction gas again. In case that the scrubber 24 injects water, the water absorbing the dust may be discharged outward as sludge. The sludge may be supplied to the apparatus 10 for manufacturing the binderless briquette through the sludge supplying line 95.

[78] FG 6 schematically illustrates the compacted iron forming device 30 in FG 3 from which the reduced iron ore is discharged.

[79] As illustrated in FG 6, in case that the compacted iron is crushed by the crusher

304, the compacted iron is crusted to generate a dust, i.e., the reduced iron ore. Thus, the reduced iron ore may be supplied to the apparatus 10 for manufacturing the binderless briquette through the reduced iron ore supplying line 85 from the crusher 304.

[80] The offgas including an amount of dust may be discharged outward from the storage

301 because the fine direct reduced iron is charged into the storage 301. Thus, the dust included in the offgas is removed by water provided from the scrubber 32 and the offgas may be then discharged outward. The water including the dust may become a sludge in the scrubber 32. The sludge may be supplied to the apparatus 10 for manufacturing the binderless briquette through the sludge supplying line 95.

[81] In addition, the fine direct reduced iron is compressed and molded by the pair of rolls

302 to generate the offgas. Here, the offgas may include an amount of dust. Thus, the scrubber 34 may spray water to the offgas to remove the dust from the offgas. The water including the dust becomes the sludge. The sludge is then supplied to the apparatus 10 for manufacturing the binderless briquette through the sludge supplying line 95.

[82] Procedures for discharging the reduced iron ore and the sludge in FG 5 and FD 6 are examples that dose not limit the present invention. Thus, another procedure may be employed to discharge the reduced iron ore and the sludge.

[83] FD 7 schematically illustrates the storage 50 in FD 3 from which the sludge is d ischarged.

[84] As illustrated in FD 7, in case that the compacted iron is charged into the storage

50, an offgas may be generated from the storage 50 due to the compacted iron. The offgas is discharged outward through the offgas line 52 connected to the storage 50. The offgas includes a dust. Thus, water is supplied from the scrubber 54 to remove the dust from the offgas. The water including the dust is collected as sludge. The sludge is supplied to the apparatus 10 for manufacturing the binderless briquette through the sludge supplying line 95.

[85] FD 8 schematically illustrates an apparatus 2000 for manufacturing a molten iron where a reduced iron ore and sludge are discharged. A structure of the apparatus 2000 for manufacturing the molten iron is similar to that of the apparatus 100 for manufacturing the molten iron in FD 3. Thus, the same reference minerals will be used to designate the same parts and any further explanation will be omitted.

[86] As illustrated in FD 8, the apparatus 2000 for manufacture the molten iron includes a packed-bed reactor 58. Although not illustrated in FD 8, the apparatus 2000 for manufacturing the molten iron may include the packed-bed reactor together with the fluidized-bed reduction reactor. In addition, the apparatus 2000 for manufacturing the molten iron may include the plurality of packed-bed reactors.

[87] As illustrated in FD 8, the reduction gas generated from the melter-gasifier 60 is supplied to the packed-bed reactor 58 through the reduction gas supplying line 71. The iron ore is charged to the packed-bed reactor 58 to be transformed into the reduced iron by the reduction gas. The reduced iron is charged into the melter-gasifier 60 and the melted to form the molten iron.

[88] The offgas generated from the packed-bed reactor 58 is discharged outward through the offgas line 59. The scrubber 57 is installed at the offgas line 59 and the scrubber 57 may spray water to the offgas. An amount of dust is included in the offgas. The water may collect the dust so that the dust may be discharged from the scrubber 57 as a form of sludge. The sludge is supplied to the apparatus 10 for manufacturing the binderless briquette through the sludge supplying line 95.

[89] In addition, in case that the packed-bed reactor 58 is repaired, the packed-bed reactor 58 becomes empty. Thus, the reduced iron ore in the packed-bed reactor 58 is discharged outwardly. The reduced iron ore is supplied to the apparatus 10 for manufacturing the binderless briquette through the reduced iron ore supplying line 85. Thus, the apparatus 10 for manufacturing the binderless briquette may manufacture the binderless briquette by using the reduced iron ore.

[90] Hereinafter, the present invention is more fully described with reference to examples. The examples are provided so that this disclosure will be thorough and complete, and this invention should not be construed as limited to the examples set forth herein.

[91] EXAMPLE [92] An experiment for manufacture a binderless briquette by using a recued iron ore and a dust as sources

[93] Ingredients included in the dust and the reduced iron ore used in the apparatus for manufacturing the binderless briquette in FD 1 were analyzed. The ingredients of the dust and the reduced iron ore are disclosed below TABLE 1.

[94] Table 1 [Table 1] [Table ]

[95] As disclosed in TABLE 1, the iron content of the reduced iron ore is relatively high because the reduced iron ore is partially reduced. On the other hand, the ingredients of the dust are substantially the same as those included in the iron ore because the dust is collected when the iron ore is dried.

[96] Various experiments were performed to manufacture a superior binderless briquette by using the dust and the reduced iron ore. Here, the binderless briquette may have a high strength at a high temperature such that the binderless briquette may not be separated by the reduction gas in the melter-gasifier when the binderless briquette is charged into the melter-gasifier.

[97] EXAMPLE 1

[98] The mixture including the dust and the reduced iron ore was compressed and molded by using a pair of shaping rolls substantially same as the pair of shaping rolls 1104 in FD 1. Here, the diameter of the reduced iron ore was below about 5mm. A toque of the pair of shaping rolls was controlled to change molding pressures variously and the binderless briquettes were manufactured. Compressive strengths of the binderless briquettes were measured. When the binderless briquettes were manufactured, the varied molding pressures were 4t/cm, 6t/cm, 8t/cm and lOt/cm. The compressive strengths binderless briquette were measured with respect to each molding pressure.

[99] A Result of EXAMPLE 1

[100] FG 9 illustrates a variation of the compressive strength of the binderless briquette in according to EXAMPLE 1. The compressive strengths of the binderless briquette corresponding to each molding pressures are indicated using a black circle or a white circle in FD 9. In addition, the compressive strengths of the binderless briquettes are indicated as dotted lines by using a least square method in FD 9.

[101] As illustrated in FD 9, when the molding pressure increases from 4t/cm to lOt/cm, the compressive strength of the binderless briquette may linearly increase. A minimum value of the compressive strength required to transfer the binderless briquette was about 50kgf/p. In addition, in case that the binderless briquette is charged into the melter-gasifier, a separation rate was decreased when the compressive strength of the binderless briquette was over about 80kgf/p. Thus, it is possible to charge the binderless briquette to the melter-gasifier when the compressive strength of the binderless briquette was over about 80kgf/p. That is, the compressive strength of the binderless briquette may be about 80kgf/p to about 100kgf/p. In case that the compressive strength of the binderless briquette is large, a large molding pressure is required so that a load applied to the pair of shaping rolls may be too large.

[102] Referring to the dotted line in FD 9, the compressive strength of 80kgf/p corresponds to the molding pressure of 6t/cm. Thus, the molding pressure may be 6t/cm to lOt/cm. In case that the molding pressure is too small, the compressive strength of the binderless briquette is too small so that the binderless briquette may not be charged into the melter-gasifier. On the other hand, in case that the molding pressure is too large, a load applied to the pair of shaping rolls is too large so that the shaping rolls may be broken.

[103] EXAMPLE 2 [104] The mixture including the dust and the reduced iron ore was compressed and molded by using a pair of shaping rolls substantially same as the pair of shaping rolls 1104 in FD 1. Here, the molding pressure of the pair of shaping rolls was about 6t/cm. The binderless briquettes were manufactured by using reduced iron ores having various diameters. The compressive strengths of the binderless briquettes were measured. The binderless briquettes were manufactured by using reduced iron ores having diameters of below about lmm, below about 5mm and below about 10mm.

[105] EXAMPLE 3

[106] The mixture including the dust and the reduced iron ore was compressed and molded by using a pair of shaping rolls substantially same as the pair of shaping rolls 1104 in FD 1. Here, the molding pressure of the pair of shaping rolls was about lOt/cm. The binderless briquettes were manufactured by using reduced iron ores having various diameters. The compressive strengths of the binderless briquettes were measured. The binderless briquettes were manufactured by using reduced iron ores having diameters of below about lmm, below about 5mm and below about 10mm.

[107] Results of EXAMPLE 2 and EXAMPLE 3

[108] FD 10 is a graph illustrating a variation of the compressive strength of the binderless briquette according to EXAMPLE 2 and EXAMPLE 3. A rectangle in FD 10 illustrates EXAMPLE 2. A circle in FG 10 illustrates EXAMPLE 3. In addition, the compressive strengths of the binderless briquettes are indicated as dotted lines by using a least square method in FD 10. A lower dotted line indicates EXAMPLE 2. An upper dotted line indicates EXAMPLE 3.

[109] As illustrated in FD 10, when the diameter of the reduced iron ore increased the compressive strength of the binderless briquette was decreased. In addition, when comparing EXAMPLE 2 and EXAMPLE 3, the compressive strength of the binderless briquette in EXAMPLE 2 may decrease in small according to an increase in the diameter rather than the compressive strength of the binderless briquette in EXAMPLE 3. Thus, in case that the molding pressure is small, the compressive strength of the binderless briquette may not largely affected by the diameter of the reduced iron ore.

[110] The diameter of the reduced iron ore may be about lmm to about 5mm. In case that the diameter of the reduced iron ore is too small (e.g., below about lmm), an efficiency for sorting diameters of the reduced iron ore decreases although the compressive strength of the binderless briquette is high. In addition, energy is largely consuned. On the other hand, in case that the diameter is too large, filling rate of the mixture in a concave portion of the shaping roll when the binderless briquette is man- ufactured becomes low. Thus, processes for manufacturing the binderless briquette become unstable.

[I l l] EXAMPLE 4

[112] The mixture including the dust and the reduced iron ore was compressed and molded by using a pair of shaping rolls substantially same as the pair of shaping rolls 1104 in FD 1. Here, the amounts of the moisture in the reduced iron ores were varied. The varied amounts of the moisture were 0wt%, 3wt%, 6wt%, 9wt%, 12wt%, and 17.5wt%. The compressive strengths of the binderless briquettes were measured.

[113] EXAMPLE 5

[114] The mixture including the dust and the reduced iron ore was compressed and molded by using a pair of shaping rolls substantially same as the pair of shaping rolls 1104 in FD 1. Here, the amounts of the moisture in the reduced iron ores were varied. The varied amounts of the moisture were 0wt%, 3wt%, 6wt%, 9wt%, 12wt%, and 17.5wt%. The compressive strengths of the binderless briquettes were measured. A reduced iron ore different from the reduced iron ore in EXAMPLE 4 was used in EXAMPLE 5.

[115] Results of EXAMPLE 4 and EXAMPLE 5

[116] FD 11 is a graph illustrating a variation of the compressive strength of the binderless briquette according to EXAMPLE 4 and EXAMPLE 5. A circle in FD 11 illustrates EXAMPLE 4. A rectangle in FD 11 illustrates EXAMPLE 5. In addition, the compressive strengths of the binderless briquettes are indicated as dotted lines by using a least square method in FD 11.

[117] As illustrated in FD 11, when the amount of moisture in the reduced iron ore increased, the compressive strength of the binderless briquette linearly decreased. When the amount of moisture in the reduced iron ore increased, the mixture was adhered to a surface of the pair of shaping rolls to decrease molding characteristics. Thus, the amount of moisture is controlled under about 6wt%. In case that the amount of moisture is over about 6wt%, the compressive strength of the binderless briquette may largely decrease.

[118] EXAMPLE 6

[119] The mixture including the dust and the reduced iron ore was compressed and molded by using a pair of shaping rolls substantially same as the pair of shaping rolls 1104 in FD 1. Here, the amount of moisture in the reduced iron ore was about 0wt%. The amount of dust mixed with the reduced iron ore was increased. The increased amounts of the moisture were 0wt%, 20wt%, 40wt%, 60wt%, 80wt%, and 100wt%. The compressive strengths of the binderless briquettes were measured.

[120] EXAMPLE 7

[121] The mixture including the dust and the reduced iron ore was compressed and molded by using a pair of shaping rolls substantially same as the pair of shaping rolls 1104 in FD 1. Here, the amount of moisture in the reduced iron ore was about 3wt%. The amount of dust mixed with the reduced iron ore was increased. The increased amounts of the moisture were 0wt%, 20wt%, 40wt%, 60wt%, 80wt%, and 100wt%. The compressive strengths of the binderless briquettes were measured.

[122] Results of EXAMPLE 6 and EXAMPLE 7

[123] FG 12 is a graph illustrating a variation of the compressive strength of the binderless briquette according to EXAMPLE 6 and EXAMPLE 7. A circle in FD 12 illustrates EXAMPLE 6. A rectangle in FG 12 illustrates EXAMPLE 7. In addition, the compressive strengths of the binderless briquettes are indicated as dotted lines by using a least square method in FD 12.

[124] As illustrated in FD 12, when the amount of the dust increases, the compressive strength of the binderless briquette may decrease. In case that the amount of the dust is lower than about 50wt%, it is possible to obtain the compressive strength of the binderless briquette properly. In case that the amount of dust is over about 50wt%, the compressive strength of the binderless briquette may largely decrease. Thus, it is not suitably to use the binderless briquette to the melter-gasifier.

[125] An experiment for manufacturing a binderless briquette by using sludge as a source

[126] Ingredients included in the sludge, the dust and the reduced iron ore used in the apparatus for manufacturing the binderless briquette in FD 2 were analyzed. The ingredients of the sludge, the dust and the reduced iron ore are disclosed below TABLE 2.

[127] Table 2

[Table 2] [Table ]

[128] A small amount of sludge was reduced in the fluidized-bed reduction reactor. The reduced iron ore was partially reduced. In gradients of the sludge was substantially similar to those of the reduced iron ore. Iron contents of the sludge and the reduced iron ore was relatively high. Particularly, the iron contents of the sludge and the reduced iron ore were about 50.03wt% and about 73.39wt%, respectively, as indicated in TABLE 2. The dust may include ingredients similar to those of the iron ore because the dust was collected when the iron ore was dried.

[129] As indicated TABLE 2, the sludge included about 10.3wt% carbon. Thus, when the binderless briquette was manufactured in a cooling state, a crack due to carbon may be generated in the binderless briquette. Thus, the binderless briquette may have a relatively low compressive strength of about 20kgf/p to about 30kgf/p. Thus, the sludge, the dust and the reduced iron ore were heated and mixed to manufacture the binderless briquette. That is, the mixture including the sludge, the dust and the reduced iron ore was compressed and molded by using a pair of shaping rolls substantially same as the pair of shaping rolls 1104 in FG 2 so that the binderless briquette having a proper compressive strength were manufactured.

[130] EXAMPLE 8

[131] A mixture including the sludge, the dust and the reduced iron ore were manufactured. Here, a tinderless briquette was manufactured by changing the amounts of sludge included in the mixture. Particularly, the amounts of sludge were varied within a range of about 50wt% to about 80wt% to manufacture the tinderless briquettes. Compressive strengths of the tinderless briquettes were measured.

[132] A Result of EXAMPLE 8

[133] FG 13 illustrated a variation of compressive strength of tinderless briquette in accordance with the amounts of sludge in EXAMPLE 8.

[134] As illustrated in FD 13, when the amount of sludge included in the mixture increases, the compressive strength of the tinderless briquette gradually deceases. In case that the tinderless briquette is charged into the melter-gasifier, it is required to properly maintain the compressive strength of the tinderless briquette in order to prevent a separation of the tinderless briquette at a relatively high temperature. Thus, the amount of sludge in the mixture is maintained lower than about 55wt%. In case that the amount of the sludge is over about 55wt%, the compressive strength of the briquette may decease so that the briquette may be unsuitable to be used in the melter- gasifier.

[135] EXAMPLE 9

[136] A mixture including the sludge, the dust and the reduced iron ore was manufactured. Here, a tinderless briquette was manufactured by varying a ratio of the amount of the reduced iron ore with respect to the amount of the dust included in the mixture. Particularly, when the tinderless briquette was manufactured, the ratio of the amount of the reduced iron ore with respect to the amount of the dust included in the mixture was varied in a range of about 1/4 to about 1/2. The compressive strengths of the tinderless briquettes were measured.

[137] A result of EXAMPLE 9

[138] FD 14 is a graph illustrating a variation of the compressive strength of the tinderless briquette in accordance with the ratio of the amount of the reduced iron ore with respect to the amount of the dust included in the mixture in EXAMPLE 9.

[139] As illustrated in FD 14, when the ratio of the reduced iron ore with respect to the dust increases, the compressive strength of the tinderless briquette decreases. In case that the tinderless briquette is charged into the melter-gasifier, it is required to properly maintain the compressive strength of the tinderless briquette in order to prevent a separation of the tinderless briquette at a relatively high temperature. The compressive strength of the tinderless briquette may be no less than about 80kgf/p. Thus, the amount of the reduced iron ore may be maintained such that the amount of the reduced iron ore is substantially the same as the amount of the dust. That is, the ratio of the reduced iron ore with respect to the amount of the dust is maintained at about 1.

[140] EXAMPLE 10

[141] A mixture including the sludge, the dust and the reduced iron ore was manufactured. The binderies s briquette was manufactured by varying the heating temperature of the mixture. Particularly, the heating temperature was varied within a range of about 17O⁰C to about 400⁰C to manufacture the binderless briquettes. The compressive strengths of the binderless briquettes were measured.

[142] A result of EXAMPLE 10

[143] FG 15 is a graph illustrating a variation of the compressive strength of the binderless briquette according to the heating temperature of the mixture in a mixer in EXAMPLE 10.

[144] As illustrated in FD 15, a compressive strength of the binderless briquette increase. In case that the binderless briquette is charged into the melter-gasifier, it is required to properly maintain the compressive strength of the binderless briquette in order to prevent a separation of the binderless briquette at a relatively high temperature. Thus, the proper compressive strength may be obtained by heating the mixture at a temperature of about 35O⁰C to about 400⁰C. When the mixture is thermally treated at a temperature of below about 35O⁰C, the compressive strength of the binder briquette was relatively small because a binder is sufficiently supplied from the mixture. In addition, in case that the mixture is thermally treated at a temperature of over about 400⁰C, it is impossible to mold the binderless briquette because the mixture is adhered to the pair of the shaping rolls.

[145] EXAMPLE 11

[146] A mixture including the dust and the sludge was manufactured. The mixture including the dust and the sludge was compressed and molded by using a pair of shaping rolls substantially same as the pair of shaping rolls 1104 in FD 2. Here, a molding pressure of the pair of the shaping rolls was about lOt/cm and the molding temperature was about 400⁰C. When the mixture was manufactured, the amounts of the dust were changed such that the amounts of the dust were about 80wt%, 60wt%, 40wt%, and 0wt%. The amounts of sludge corresponding to the amounts of the dust were controlled such that the amounts of sludge became 20wt%, 40wt%, 60wt%, and 100wt%. The binderless briquette is molded by using the mixture. The compressive strength of the binderless briquette was measured. [147] A result of EXAMPLE 11

[148] FG 16 is a graph illustrating a variation of the compressive strength according to the amount of dust and the amount of sludge in EXAMPLE 11.

[149] As illustrate in FD 16, when the amount of the dust decreased, the compressive strength of the tinderless briquette decreased. However, when the amount of the sludge is over about 60wt%, the compressive strength of the binderless briquette increased again. The compressive strength of the binderless briquette was no more than about 100kgf/p.

[150] In case that the binderless briquette is charged into the melter-gasifier, it is required to properly maintain the compressive strength of the binderless briquette in order to prevent a separation of the binderless briquette at a relatively high temperature. The compressive strength of the binderless briquette may be over about 80kgf/p. Thus, as indicated using a dotted line, the amount of dust in the mixture may range between about 70wt% to about 100wt%. In case that the amount of the dust is lower than about 70wt%, the compressive strength of the binderless briquette may deteriorated so that the binderless briquette may not be suitable to be used in the melter-gasifier.

[151] EXAMPLE 12

[152] A mixture including the reduced iron ore and the sludge was manufactured. The mixture including the dust and the sludge was compressed and molded by using a pair of shaping rolls substantially same as the pair of shaping rolls 1104 in FD 2. Here, a molding pressure of the pair of the shaping rolls was about lOt/cm and the molding temperature was about 400⁰C. When the mixture was manufactured, the amounts of the reduced iron ore were changed such that the amounts of the dust were about 100wt%, 80wt%, 60wt%, 40wt%, and 0wt%. The amounts of sludge corresponding to the amounts of the reduced iron ore were controlled such that the amounts of sludge became 0wt%, 20wt%, 40wt%, 60wt%, and 100wt%. The binderless briquette is molded by using the mixture. The compressive strength of the binderless briquette was measured.

[153] A result of EXAMPLE 12

[154] FD 17 is a graph illustrating a variation of the compressive strength according to the amount of reduced iron ore and the amount of sludge in EXAMPLE 12.

[155] As illustrate in FD 17, when the amount of the reduced iron ore decreased, the compressive strength of the binderless briquette decreased. In addition, in case that the amount of the reduced iron ore was lower than about 60wt%, the compressive strengths of the binderless briquettes were substantially similar. In case that the tinderless briquette is charged into the melter-gasifier, it is required to properly maintain the compressive strength of the tinderless briquette in order to prevent a separation of the tinderless briquette at a relatively high temperature. The compressive strength of the tinderless briquette may be over about 80kgf/p. Thus, as indicated using a dotted line, the amount of the reduced iron ore in the mixture may range between about 70wt% to about 100wt%. In case that the amount of the reduced iron ore is lower than about 70wt%, the compressive strength of the tinderless briquette may deteriorated so that the tinderless briquette may not be suitable to be used in the melter-gasifier.

[156] The foregoing is illustrative of the present invention and is not to be construed as limiting thereof. Although a few embodiments of this invention have been described, those skilled in the art will readily appreciate that many modifications are possible in the embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the claims. Therefore, it is to be understood that the foregoing is illustrative of the present invention and is not to be construed as limited to the specific embodiments disclosed, and that modifications to the disclosed embodiments, as well as other embodiments, are intended to be included within the scope of the appended claims. The invention is defined by the following claims, with equivalents of the claims to be included therein.

[157]

Claims

[I] A method of manufacturing a tinderless briquette, the method comprising: providing a dust gathered by using a dry collection manner from an offgas discharged when an iron ore is dried; providing a reduced iron ore discharged from an apparatus for manufacturing a molten iron including a reduction furnace providing a reduced iron obtained by reducing the dried iron ore and a melter-gasifier manufacturing the molten iron by melting the reduced iron; providing a sludge discharged from the apparatus for manufacturing the molten iron; providing a mixture formed by drying and mixing at least two sources selected from the group consisting of the dust, the reduced iron ore and the sludge; and forming the tinderless briquette by molding the mixture without adding a binder. [2] The method of Claim 1, wherein, in the providing the reduced iron ore, the reduced iron ore is provided after drying and size sorting. [3] The method of Claim 2, wherein the reduced iron ore includes moisture ranging about 10wt% to about 30wt% before the reduced iron ore is dried and size sorted. [4] The method of Claim 2, wherein a reduction rate of the reduced iron ore is about

30% to about 60%. [5] The method of Claim 4, wherein the reduced iron ore is size sorted to be divided into a coarse reduced iron ore and a fine reduced iron ore, and the coarse reduced iron ore is charged into the melter-gasifier. [6] The method of Claim 5, wherein a diameter of the coarse reduced iron ore is over about 8mm. [7] The method of Claim 1, wherein a molding pressure is about 6t/cm to about lOt/cm when molding the mixture in forming the tinderless briquette. [8] The method of Claim 1, wherein the amount of moisture in the reduced iron ore is about 0 to about 6wt% in providing the mixture. [9] The method of Claim 1, wherein the diameter of the reduced iron ore is about lmm to about 5mm in providing the mixture. [10] The method of Claim 1, wherein the amount of the dust in the mixture is about 0 to about 50wt% in providing the mixture.

[I I] The method of Claim 1, wherein the reduced iron is provided from the reduction furnace in providing the reduced iron ore.

[12] The method of Claim 1, wherein, in providing the reduction iron ore, the apparatus for manufacturing the molten iron further comprises a compacted iron forming device connecting the reduction furnace and the melter-gasifier to each other and supplying a compacted iron formed by compacting the reduced iron discharged from the reduction furnace to the melter-gasifier, and the reduced iron ore is supplied from the compacted iron forming device.

[13] The method of Claim 1, wherein, in forming the binderless briquette, the strength of the binderless briquette is about 80kgf/p to about 100kgf/p.

[14] The method of Claim 1, wherein, in providing the sludge, the sludge is provided after the sludge is dried and crushed.

[15] The method of Claim 14, wherein the sludge includes about 30wt% to about

40wt% of moisture before the sludge is dried and crushed.

[16] The method of Claim 1, wherein, in providing the mixture, the mixture is formed by mixing the dust, the reduced iron ore and the sludge, and the amount of sludge in the mixture is about 0wt% to about 55wt%.

[17] The method of Claim 16, wherein the amount of the reduced iron ore is substantially the same as the amount of the dust.

[18] The method of Claim 1, wherein, in providing the mixture, the mixture is formed by mixing the dust and the sludge, and the amount of the dust in the mixture is about 70wt% to about 100wt%.

[19] The method of Claim 1, wherein, in providing the mixture, the mixture is formed by mixing the reduced iron ore and the sludge, and the amount of reduced iron ore in the mixture is above 70wt% to about 100wt%.

[20] The method of Claim 1, wherein, in providing the mixture, the mixture is thermally treated at a temperature of about 35O⁰C to about 400⁰C.

[21] An apparatus for manufacturing a binderless briquette, the apparatus comprising: a dust hopper gathering a dust from an offgas discharged when an iron ore is dried by using a dry collection manner and storing the collected dust; a reduced iron ore hopper storing a reduced iron ore discharged from an apparatus for manufacturing a molten iron including a reduction furnace providing a reduced iron obtained by reducing the dried iron ore and a melter- gasifier manufacturing the molten iron by melting the reduced iron; a sludge hopper storing a sludge discharged from the apparatus for manufacturing the molten iron; a mixture connected to the dust hopper, the reduced iron ore hopper, and the sludge hopper and mixing and heating at least two sources selected from the group consisting of the dust, the reduced iron ore and the sludge to provide a mixture; and a pair of shaping rolls molding the mixture to form the binderless briquette. [22] The apparatus of Claim 21, wherein the mixer comprises: a casing; and a rotation member rotating in the casing. [23] The apparatus of Claim 22, wherein the rotation member is a screw-typed member extending in a predetermined direction to be rotated in the casing. [24] The apparatus of Claim 21, further comprising: a drier drying the sludge; and a crusher connecting the drier and the sludge to each other and crush the sludge. [25] The apparatus of Claim 24, wherein the drier is a rotary kiln.

[26] The apparatus of Claim 21, further comprising: a drier drying the reduced iron ore; and a size sorter connecting the drier and the reduced iron ore hopper to each other and size sorting the dried reduced iron ore to divide the dried reduced iron ore into a fine reduced iron ore and a coarse reduced iron ore. [27] The apparatus of Claim 26, wherein the drier is a rotary kiln.

[28] The apparatus of Claim 26, wherein the coarse reduced iron ore is charged into the melter-gasifier. [29] The apparatus of Claim 21, wherein the reduction furnace provides the reduced iron ore hopper with the reduced iron ore. [30] The apparatus of Claim 21, wherein the mixture is thermally treated at a temperature of about 35O⁰C to about 400⁰C. [31] The apparatus of Claim 21, wherein the apparatus of manufacturing the molten iron further comprises a compacted iron forming device connecting the reduction furnace and the melter-gasifier to each other and he reduced iron ore is supplied from the compacting iron forming device to the reduced iron ore hopper. [32] The apparatus of Claim 21, wherein the pair of shaping roll molds the mixture at a molding pressure of about 6t/cm to about lOt/cm. [33] The apparatus of Claim 30, wherein the reduction furnace is a fluidized-bed reduction reactor or a packed-bed reactor.