Classifications

• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21B—MANUFACTURE OF IRON OR STEEL
  • C21B13/00—Making spongy iron or liquid steel, by direct processes
  • C21B13/0006—Making spongy iron or liquid steel, by direct processes obtaining iron or steel in a molten state
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21B—MANUFACTURE OF IRON OR STEEL
  • C21B11/00—Making pig-iron other than in blast furnaces
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
  • F27B3/00—Hearth-type furnaces, e.g. of reverberatory type; Tank furnaces
  • F27B3/10—Details, accessories, or equipment peculiar to hearth-type furnaces
  • F27B3/22—Arrangements of air or gas supply devices
  • F27B3/225—Oxygen blowing
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
  • F27D1/00—Casings; Linings; Walls; Roofs
  • F27D1/12—Casings; Linings; Walls; Roofs incorporating cooling arrangements
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
  • F27D17/00—Arrangements for using waste heat; Arrangements for using, or disposing of, waste gases
  • F27D17/001—Extraction of waste gases, collection of fumes and hoods used therefor
  • F27D17/003—Extraction of waste gases, collection of fumes and hoods used therefor of waste gases emanating from an electric arc furnace
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21B—MANUFACTURE OF IRON OR STEEL
  • C21B2100/00—Handling of exhaust gases produced during the manufacture of iron or steel
  • C21B2100/40—Gas purification of exhaust gases to be recirculated or used in other metallurgical processes
  • C21B2100/44—Removing particles, e.g. by scrubbing, dedusting

Definitions

• the present invention relates to a method and an apparatus for producing iron by melt reduction of concentrate or prereduced concentrate in a melt bath in a reactor, e.g. a converter, wherein concentrate or prereduced and partially molten concentrate and carbonaceous reducing agent, such as coal, is supplied to the melt bath consisting of a layer of molten iron and a layer of slag floating thereon; oxygen-containing gas, such as hot air, is blown into a so-called post-combustion zone by means of blowpipes towards the slag layer in order to bring about combustion of the reduction gases being discharged so as to heat the melt bath; the hot exhaust gases produced are discharged through an outlet in the roof of the reactor.
• a reactor e.g. a converter
• concentrate or prereduced and partially molten concentrate and carbonaceous reducing agent such as coal
• the method according to the invention is characterized in that oxygen-containing gas is blown into a post-combustion zone in the converter, which zone is shielded from the walls of the reactor by cooled panels so as to prevent the slag and metal drops splashing up during the blowing from reaching the uncooled walls of the reactor in the gas phase.
• the apparatus for producing iron by melt reduction of concentrate is characterized in that a shield made of cooled panels is arranged to shield the post-combustion zone from the tile walls of the reactor or corresponding means in an area between the slag layer and the outlet for exhaust gases.
• the post-combustion takes place in a space shielded by cooled panels from the remaining parts of the reactor.
• the panel or panels prevent hot molten drops, which splash up into the gas phase in the post-combustion stage, from reaching the tile walls of the reactor.
• the panel which may be, for instance, water-, gas- or steam-cooled, endures the wear of these drops considerably better than the uncooled tile wall.
• the panel can be provided with a heat-insulating layer on its outside in order to prevent unnecessary cooling in the remaining part of the reactor. In most cases a protecting layer of solidified drops is anyhow formed on the panels.
• the cooled panel is preferably shaped as an upright cylinder disposed concentrically between the surface of the slag and the gas outlet.
• the cylinder surrounds thereby the post-combustion zone of the reactor.
• the cooled panel can, if needed, be widened at its upper or lower end so that the shielded zone takes the form of a frustum of cone.
• the gas volumes can be so large that it is advantageous to widen the space shielded by the panels at its lower end.
• the shield can have a square, rectangular or, for instance, hexagonal cross section.
• the shield is thus formed of plane water-cooled panels or membrane walls, which is an advantage in the manufacturing stage.
• the cooled panels are preferably fastened to the roof of the reactor. If needed, openings can be provided in the upper part of the panels or between the panels and the roof of the reactor so that also gases produced outside the shielded part can flow to the gas outlet. Possibly these gases could be withdrawn from the reactor through a separate gas outlet.
• the lower edge of the cooled panels can in certain cases be allowed to reach the slag surface.
• a gap between the slag surface and the panels or the openings in the lower parts of the panels allows the gases to flow, if necessary, from the space outside the post-combustion zone via the shielded zone to the gas outlet.
• the oxygen-containing gas required in the post-combustion stage is preferably introduced tangentially into the converter by means of one or several blowpipes so that the hot gases flowing upwards form a vortex in the shielded part of the reactor already, thereby promoting the formation of a vortex in the flame chamber.
• the illustrated plant comprises a converter 10 for melt reduction of prereduced molten concentrate.
• the converter is internally lined with tiles 11.
• the gas outlet 12 of the converter is connected to a flame chamber 14 for prereduction and smelting of concentrate.
• the flame chamber is provided with water-cooled membrane walls 15.
• a reactor 16 having e.g. a fluidized bed is disposed on top of the flame chamber in order to preheat the concentrate.
• Concentrate is introduced into the reactor chamber 17 of the reactor 16 through an inlet 18. Hot gases from the flame chamber are fed through an opening 20 into the bottom of the reactor.
• the concentrate is preheated by the exhaust gases in the reactor chamber and flows entrained by the upwards flowing gases via the upper part of the reactor to a particle separator 22. A portion of the preheated concentrate is recycled to the reactor chamber whereas another portion is passed to the flame chamber through a channel 24.
• Carbonaceous reducing agent 26 is at the same time introduced into the flame chamber.
• the preheated concentrate is prereduced and smelts in the flame chamber and flows down to the converter for final reduction of the iron oxide in the melt bath 28, 30 of the converter.
• the melt bath consists of a iron layer 28 on the bottom of the converter and a slag layer 30 on top of the iron layer.
• Coal 32 and hot blast air 34 is introduced into the converter through openings in the bottom of the converter. Iron and slag is withdrawn through an outlet 36 in the side of the converter.
• oxygen-containing gas such as hot blast air
• a post-combustion zone 37 oxygen-containing gas, such as hot blast air
• the blast air is blown in tangentially by the blowpipes so that upwards flowing gases form a vortex and thereby promote the formation of a vortex in the flame chamber.
• the blast air brings about a vigorous turbulence in the slag layer while the reducing gases are combusted developing heat.
• the vigorous turbulence results in a good heat transfer in the post-combustion zone between the gas phase and the slag and metal drops splashing up.
• the post-combustion zone in the converter is shielded by cooled panels 42.
• the panels have been formed by extending the cooled walls 15 of the flame chamber downward into the converter.
• the final reduction is effected by means of carbon dissolved in the metal layer.
• Hot blast air is used for the post-combustion which supplies energy to the slag layer 30 as well as the metal layer 28.
• the slag layer is thin in comparison with the iron layer.
• Other corresponding melt bath processes can use oxygen gas in a post-combustion stage, have a considerably thicker slag layer than iron layer and inject the whole amount of coal from above into the gas phase or the slag layer. In these processes the post-combustion supplies energy primarily to the expanding slag layer. Reduction is achieved by means of coke particles and iron drops suspended in the slag.
• the invention is not intended to be restricted to the above described and illustrated embodiment, in which the invention primarily is described in connection with melt reduction in a process with prereduction in a flame chamber.
• the invention can as well be used in various converter processes.
• the invention can be modified in many ways within the scope of the inventive idea defined in the appended claims.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Organic Chemistry (AREA)
• Metallurgy (AREA)
• Manufacturing & Machinery (AREA)
• Environmental & Geological Engineering (AREA)
• Manufacture Of Iron (AREA)
• Carbon Steel Or Casting Steel Manufacturing (AREA)
• Manufacture And Refinement Of Metals (AREA)
• Furnace Details (AREA)

Applications Claiming Priority (3)

Publications (1)

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ID=8537466

Family Applications (1)

Country Status (11)

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Family Cites Families (5)

• 1993
  • 1993-02-26 FI FI930864A patent/FI93027C/sv not_active IP Right Cessation
• 1994
  • 1994-01-21 WO PCT/FI1994/000023 patent/WO1994019497A1/en not_active Application Discontinuation
  • 1994-01-21 CA CA002156631A patent/CA2156631A1/en not_active Abandoned
  • 1994-01-21 JP JP6518683A patent/JPH08506858A/ja active Pending
  • 1994-01-21 BR BR9406272-2A patent/BR9406272A/pt unknown
  • 1994-01-21 CN CN94191797A patent/CN1121358A/zh active Pending
  • 1994-01-21 EP EP94905111A patent/EP0686204A1/en not_active Withdrawn
  • 1994-01-21 KR KR1019950703611A patent/KR960701224A/ko not_active Application Discontinuation
  • 1994-01-21 AU AU58854/94A patent/AU673049B2/en not_active Expired - Fee Related
  • 1994-02-04 ZA ZA94772A patent/ZA94772B/xx unknown
  • 1994-02-17 TW TW083101316A patent/TW260711B/zh active

Non-Patent Citations (1)

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