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
  • C21B13/004—Making spongy iron or liquid steel, by direct processes in a continuous way by reduction from ores
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21B—MANUFACTURE OF IRON OR STEEL
  • C21B13/00—Making spongy iron or liquid steel, by direct processes
• • 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
  • C21B13/00—Making spongy iron or liquid steel, by direct processes
  • C21B13/0033—In fluidised bed furnaces or apparatus containing a dispersion of the material
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21B—MANUFACTURE OF IRON OR STEEL
  • C21B13/00—Making spongy iron or liquid steel, by direct processes
  • C21B13/0073—Selection or treatment of the reducing gases
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P10/00—Technologies related to metal processing
  • Y02P10/10—Reduction of greenhouse gas [GHG] emissions
  • Y02P10/122—Reduction of greenhouse gas [GHG] emissions by capturing or storing CO2

Definitions

• the invention relates to methods and apparatus for the reduction of iron ore-containing feedstocks or for the production of pig iron or liquid steel precursors in a melting unit, in particular a melter gasifier, wherein the starting materials are at least partially reduced in at least one reduction unit, in particular a fluidized bed reactor by means of a reducing gas and optionally at least a portion of the at least partially reduced feedstocks in a melter gasifier or in a blast furnace with supply of coal or coke and oxygen-containing gas are melted with simultaneous formation of the reducing gas and the reducing gas or in a external, in particular in a reforming process, generated reducing gas is fed to the reduction unit ,
• the problem is that in case of disturbances of the process or at planned shutdowns, the starting materials must be removed from the aggregates so that they do not cool and it does not freeze, so the solidification of the starting materials the process reactors comes. Furthermore, the feedstock must be removed before scheduled shutdowns in order to perform a maintenance of the system. Due to the size of the plants, in the case of a standstill, mostly large quantities of hot starting materials must be able to be handled.
• the invention is in an interruption of the reduction process or the pig iron or steel precursor production, as z. B. takes place in a process standstill, which empties at least one reduction unit. But it is also conceivable that only a partial stream of production is discharged.
• the at least partially reduced and usually hot starting materials, such as fine-grained or lumpy iron ores are introduced into at least one vessel, such as a bunker or another reduction unit, and kept under a non-oxidizing inert gas atmosphere.
• the protective gas atmosphere ensures that there is no renewed oxidation of the already at least partially reduced feedstocks.
• the reduction state of the starting materials can be maintained even in the case of an interruption of the process for the production of pig iron or steel precursors and subsequent use after completion of the standstill, such as in the continuation of the process supplied.
• Elaborate treatments of the starting materials can be omitted, in particular, can be achieved by continuing the process quickly stable operating condition.
• the process can be stopped more cost-effectively and the reduction unit emptied. This allows a shorter duration for the cooling of the system and thus reduced downtime due to work on the system.
• the costs for processing the starting materials are reduced since they no longer have to be cooled in a water bath and subsequently treated, as is customary in the prior art. By eliminating this cooling in a water bath eliminates the processing of the resulting sludge and the necessary for subsequent processing facilities.
• the emptied starting materials are cooled to a temperature, in particular below 150 ° C., during which no reoxidation of the starting materials takes place. Since oxidation processes proceed more rapidly with increasing temperature, the reoxidation can be largely suppressed by cooling, even when stored in air, since the oxidation processes are hardly or only very slowly.
• An advantageous embodiment of the method according to the invention provides that the starting materials in the vessel for material loosening and / or for inerting and / or for at least partial cooling with a protective gas, in particular nitrogen, are rinsed.
• a protective gas in particular nitrogen
• the starting materials are thus first removed from the reduction unit and stored under a protective gas atmosphere in the vessel.
• the starting materials can be stored intermediately or cooled in a controlled manner.
• the cooling can take place during the discharge from the vessel by means of cooling screws.
• the starting materials are guided by means of a screw through a (water) cooled tubular housing in which the (water) cooled screw is arranged, thereby strongly cooled and discharged from the vessel.
• the cooled starting materials are transported out of the vessel, in particular pneumatically by means of a carrier gas, into a bearing for storing the cooled starting materials.
• the pneumatic transport of the feedstock which has been discharged from the vessel is a particularly simple and inexpensive solution, using as carrier gas e.g. Inert gas from the vessel or other process gas or mixtures thereof can be used.
• a special embodiment of the method according to the invention provides that the starting materials are introduced into the metallurgical vessel at the operating pressure of the reduction unit.
• the operating pressure can be used to transport the feedstock into the vessel, wherein the pressure in the vessel can be set correspondingly lower than the operating pressure.
• the pressure in the vessel before a discharge of the starting materials in particular to a differential pressure of at least 0, 1 bar, in particular to at least 0.5 bar relative to the reduction unit, lowered.
• the pressure in the vessel can therefore be adjusted accordingly when filling from the reduction unit to its operating pressure and lowered before the discharge of the starting materials from the vessel again.
• the pressure difference in the vessel to the environment, in which the starting materials are discharged can be adjusted.
• An advantageous embodiment of the method according to the invention is achieved by the reduction gas, which is introduced together with the feedstock into the vessel, is introduced into an entry container for charging reduced feedstocks in a Brikettier Anlagen.
• Aggregates in reduction or smelting reduction plants usually require entry containers, in which the starting materials are stored before the entry into the respective unit and which also serve to adapt the pressure to the operating pressure of the unit.
• the excess reducing gas is led out of the vessel into the feed tank.
• the starting materials are introduced alternately into at least two vessels.
• This allows for alternate use of the vessels such that e.g. one vessel can be emptied while the other vessel is being filled.
• a particular embodiment of the method according to the invention provides that the transport of the starting materials from the reduction unit into the vessel by gravity and / or pneumatically, using the reducing gas from the reduction unit as a carrier gas, takes place. If necessary, the speed at which the starting materials from the reduction unit can be brought into the vessel can be set, wherein the transport can be adjusted via the pressure of the reducing gas and the pressure difference between the reduction unit and the vessel.
• the device according to the invention for the reduction of feedstocks or for the production of pig iron or liquid steel precursors comprises at least one reduction unit, such as a reduction shaft or a fluidized bed reactor, for the at least partial reduction of iron ore containing feedstocks by means of a reducing gas, and optionally a melting aggregate, in particular a melter gasifier or a blast furnace , wherein at least a portion of the at least partially reduced feedstocks can be melted down in the melter gasifier with the supply of coal or coke and oxygen-containing gas with simultaneous formation of the reducing gas and the formed or in an external, in particular a Reformationspro- Zess, reducing gas generated via a reducing gas line is fed to the reduction unit.
• a reduction unit such as a reduction shaft or a fluidized bed reactor
• a melting aggregate in particular a melter gasifier or a blast furnace
• At least one vessel in particular a bunker or a further reduction unit, is provided, in which, in the event of an interruption of the reduction process or the production of pig iron or steel precursors, in particular during a process standstill, at least one reduction unit can be emptied.
• Inertizing devices are provided in the vessel, so that the at least partially reduced feedstocks can be introduced and kept under a non-oxidizing inert gas atmosphere.
• the inerting devices are formed by a multiplicity of protective gas connections in the vessel so that the starting materials can be rendered inert and / or fluidized and / or cooled.
• the choice of the type of vessel depends essentially on the production capacity of the plant for the reduction of iron ore-containing feedstocks or for the production of pig iron or liquid steel precursors, taking into account the needs for process stoppages.
• the capacity of the vessel or vessels are chosen such that a complete emptying in a short time is possible, for example, a duration for the complete emptying of the reduction units in about a Vi to 4 hours is considered technically realistic.
• the total volume of one or all vessels is dimensioned such that at least the starting materials can be taken up from a reduction unit and at most from all reduction units.
• At least two vessels are provided, so that they can be charged alternately with starting materials. Thereby, e.g. one container are filled while the other is emptied. A simultaneous filling of the vessels is also possible, this allows an even faster emptying of the reduction units.
• the vessel has at least one cooling screw for cooling and metered discharge of the starting materials from the vessel.
• Cooling screws have screw-like conveying devices, which are arranged in a coolable, mostly water-cooled, substantially tubular housing. Due to the high specific surface area and good mixing of the feed materials, cooling screws fulfill the special requirements regarding the cooling of hot, reduced iron oxides.
• the length of the screw, the screw shape, the diameter, the operating speeds and other parameters can be adjusted as needed, so that a specific cooling rate can be guaranteed for a defined delivery volume.
• the Number of cooling screws per vessel adapted as required.
• each vessel has 1 to 6 cooling screws. The design is carried out in such a way that a complete emptying of the vessel in about 4 to 16 hours can be ensured.
• a device for pneumatic conveying of the starting materials from the vessel which connects the vessel to a bearing for storing the cooled starting materials in air.
• the pneumatic conveying allows a simple and inexpensive transport, which can be avoided due to the elimination of mechanical conveyors wear on transport equipment due to the highly abrasive acting feeds.
• a cascade reduction units in particular fluidized bed reactors are provided, which are connected to each other via a reducing gas line, a transport line for the starting materials and a separate discharge line, so reducing gas and feedstocks in Can flow countercurrently, which in a process standstill first lowermost reduction unit R1 drained through a drain and then the next higher reduction unit can be emptied into the lower reduction unit via the separate drain line.
• the separate discharge line between the reduction units is designed such that its inlet just above the nozzle bottom of the higher reduction unit starts and thereby at least a majority of the bed material can be passed into the lower-lying reduction unit.
• the separate discharge line between the reduction units can be closed by a valve in normal operation.
• the feedstocks of the lowest-lying reduction aggregate can e.g. be supplied to a briquetting.
• the reduction units assume the role of the vessel in this embodiment, so that can be done by the stepwise emptying storage and cooling in the downstream reduction units or.
• the device according to the invention are 2 to 6, in particular 4, connected in a cascade reduction units R1, R2, R3, R4, in particular fluidized bed reactors provided, which are connected to each other via a reducing gas line and a transport line for the starting materials, so Reduction gas and feedstocks can flow in countercurrent, the reduction units are each connected to a common discharge for emptying the reduction units and the derivative with the vessel or via a Connecting line is connected to a Brikettierstrom.
• This special solution allows emptying of the reduction units via the common discharge into the vessel or in a Brikettierstrom. Subsequently, in both cases, a cooling is possible.
• the vessel is connected via an exhaust pipe to an entry container for charging reduced feedstocks into a briquetting device, so that the reducing gas discharged from the vessel can be supplied to the entry container.
• the exhaust gas line By way of the exhaust gas line, the reducing gas can be supplied to the input container on the one hand and can thus be treated in a usually existing device for purifying the reducing gas. An additional device can therefore be omitted.
• the vessel is connected via an exhaust pipe to a device for cleaning the gas discharged from the vessel, in particular a scrubber.
• a scrubber or dry dedusting means may be provided which allows for the purification of the gas discharged from the vessel, e.g. Solids, dusts, etc. are separated from the gas and the clean gas can be fed to a re-use in the reduction process.
• Fig. 1 Inventive plant for the production of pig iron or liquid steel precursors with connection to the entry container
• Fig. 2 Inventive plant for the production of pig iron or liquid steel precursors with scrubbers
• Fig. 3 Inventive plant for the reduction of iron ore-containing feedstocks with connection to the entry tank
• Fig. 4 Inventive plant for the reduction of iron ore-containing feedstocks with scrubbers
• FIG. 1 shows a melting unit 1, such as a melter gasifier, in which with the addition of carbon carriers, such as coal and / or coke K, feedstocks E, which are at least partially reduced, such as fine ore or fine iron ore, are melted, wherein a reducing gas is formed, which is introduced into the series of series-connected reduction units R1 to R4.
• the reducing gas flows countercurrent to the feedstocks E to be reduced and, if appropriate, additives.
• Z which are mixed and dried prior to entry into the reduction unit R4.
• the means for purifying the reducing gas with which the reducing gas generated in the melting unit is cleaned and its temperature set before the introduction into the reduction units, are not detailed here, since they belong to the prior art.
• the at least partially reduced feedstocks can be made 2 pieces in a hot compacting and usually still hot introduced into the entry tank 3 and melted in the melting unit 1 to pig iron RE.
• a common discharge line 4 is provided, can be derived via the feedstock from the reduction units R4, R3 and R2 in at least one vessel.
• a discharge line 14 from the reduction unit R1 is provided in a vessel.
• two vessels 5 and 6 are shown, which are provided for an alternate operation.
• the vessels 5 and 6 could also be arranged and connected in such a way that they can simultaneously receive feedstocks from the reduction aggregates.
• the vessels 5 and 6 are each equipped with inertizing devices 7a, 7b, so that the starting materials are shielded with inert gas, e.g. Nitrogen, or mixtures of shielding gases can be purged or cooled.
• a further variant of the device according to the invention is shown.
• This provides a separate discharge line 15, which is arranged in each case so that their inlet just above the nozzle bottom of the higher reduction unit begins and thereby at least a majority of the bed material can be passed into the lower-lying reduction unit.
• This separate discharge line 15 can be provided either instead of the common discharge 4 but also together with this.
• the vessels 5, 6 are each equipped with one or more screw coolers 8a, 8b, which cause cooling of the starting materials in the course of the discharge of the starting materials from the vessel.
• This is preferably done by a water-cooled housing in which at least one discharge screw with (water) cooled screw flights is arranged.
• the discharged starting materials can be introduced into a carrier gas stream in a device for pneumatic conveying 9 and thus be brought into a warehouse. Via lines 10a, 10b, a pressure equalization between the screw cooler 8a, 8b and the vessels 5, 6 is produced and the Feed gas introduced.
• the discharge of the starting materials and the pneumatic transport can take place in a closed system, so that no environmental effects such. Emissions occur.
• the starting materials from the reduction unit R1 can also be supplied to a briquetting device 2.
• the reducing gases can be supplied via scrubbers 12a, 12b to scrubbers 16a, 16b, wherein the scrubbing of the gas takes place with the addition of a scrubbing liquid.
• the purified gas CG can be supplied to a re-use in the process of pig iron or steel precursor production, the separated dust, which is obtained as sludge S for further processing.
• FIG. 3 shows a plant according to the invention for the reduction of iron-rich feedstocks with connection to the feed tank.
• Reduction gas which is optionally produced by mixing purified top gas and gas from a gas reformer, an optional C0 2 separation and cooling, becomes a Reduction unit R1 supplied.
• FIG. 4 shows a system according to the invention for the reduction of iron ore-containing feedstocks with scrubbers 16a and 16b.
• scrubbers 16a and 16b instead of the scrubbers, devices for dry cleaning, in particular for dry dedusting, could also be used.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Dispersion Chemistry (AREA)
• Manufacture Of Iron (AREA)
• Manufacture And Refinement Of Metals (AREA)
• Waste-Gas Treatment And Other Accessory Devices For Furnaces (AREA)

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• 2010
  • 2010-01-15 AT AT0004910A patent/AT509357B1/de not_active IP Right Cessation
  • 2010-12-01 CA CA2787199A patent/CA2787199A1/en not_active Abandoned
  • 2010-12-01 EP EP10785067A patent/EP2524061A1/de not_active Withdrawn
  • 2010-12-01 BR BR112012017162A patent/BR112012017162A2/pt not_active Application Discontinuation
  • 2010-12-01 US US13/522,477 patent/US8945273B2/en not_active Expired - Fee Related
  • 2010-12-01 KR KR1020127021496A patent/KR101775374B1/ko not_active Application Discontinuation
  • 2010-12-01 WO PCT/EP2010/068615 patent/WO2011085863A1/de active Application Filing
  • 2010-12-01 CN CN201080061556.1A patent/CN102695808B/zh active Active
  • 2010-12-01 UA UAA201208696A patent/UA106100C2/uk unknown
  • 2010-12-01 JP JP2012548362A patent/JP2013517376A/ja active Pending
  • 2010-12-01 AU AU2010342436A patent/AU2010342436B2/en not_active Ceased
  • 2010-12-01 RU RU2012134750/02A patent/RU2530180C2/ru active

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