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WO2008017797A1 - Post-combustion avec radiation - Google Patents

Post-combustion avec radiation Download PDF

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Publication number
WO2008017797A1
WO2008017797A1 PCT/GB2007/000571 GB2007000571W WO2008017797A1 WO 2008017797 A1 WO2008017797 A1 WO 2008017797A1 GB 2007000571 W GB2007000571 W GB 2007000571W WO 2008017797 A1 WO2008017797 A1 WO 2008017797A1
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Prior art keywords
melt
gas
combustion
radiative
oxidic
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Ceased
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PCT/GB2007/000571
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English (en)
Inventor
Noel Warner
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Publication of WO2008017797A1 publication Critical patent/WO2008017797A1/fr
Anticipated expiration legal-status Critical
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Classifications

    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B34/00—Obtaining refractory metals
    • C22B34/10—Obtaining titanium, zirconium or hafnium
    • C22B34/12—Obtaining titanium or titanium compounds from ores or scrap by metallurgical processing; preparation of titanium compounds from other titanium compounds see C01G23/00 - C01G23/08
    • C22B34/129—Obtaining titanium or titanium compounds from ores or scrap by metallurgical processing; preparation of titanium compounds from other titanium compounds see C01G23/00 - C01G23/08 obtaining metallic titanium from titanium compounds by dissociation, e.g. thermic dissociation of titanium tetraiodide, or by electrolysis or with the use of an electric arc
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21B—MANUFACTURE OF IRON OR STEEL
    • C21B13/00—Making spongy iron or liquid steel, by direct processes
    • C21B13/006—Starting from ores containing non ferrous metallic oxides
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
    • C21C5/56—Manufacture of steel by other methods
    • C21C5/567—Manufacture of steel by other methods operating in a continuous way
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B34/00—Obtaining refractory metals
    • C22B34/10—Obtaining titanium, zirconium or hafnium
    • C22B34/12—Obtaining titanium or titanium compounds from ores or scrap by metallurgical processing; preparation of titanium compounds from other titanium compounds see C01G23/00 - C01G23/08
    • C22B34/1218—Obtaining titanium or titanium compounds from ores or scrap by metallurgical processing; preparation of titanium compounds from other titanium compounds see C01G23/00 - C01G23/08 obtaining titanium or titanium compounds from ores or scrap by dry processes
    • C22B34/1231—Obtaining titanium or titanium compounds from ores or scrap by metallurgical processing; preparation of titanium compounds from other titanium compounds see C01G23/00 - C01G23/08 obtaining titanium or titanium compounds from ores or scrap by dry processes treatment or purification of titanium containing products obtained by dry processes, e.g. condensation
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B34/00—Obtaining refractory metals
    • C22B34/10—Obtaining titanium, zirconium or hafnium
    • C22B34/12—Obtaining titanium or titanium compounds from ores or scrap by metallurgical processing; preparation of titanium compounds from other titanium compounds see C01G23/00 - C01G23/08
    • C22B34/1263—Obtaining titanium or titanium compounds from ores or scrap by metallurgical processing; preparation of titanium compounds from other titanium compounds see C01G23/00 - C01G23/08 obtaining metallic titanium from titanium compounds, e.g. by reduction
    • C22B34/1281—Obtaining titanium or titanium compounds from ores or scrap by metallurgical processing; preparation of titanium compounds from other titanium compounds see C01G23/00 - C01G23/08 obtaining metallic titanium from titanium compounds, e.g. by reduction using carbon containing agents, e.g. C, CO, carbides
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B34/00—Obtaining refractory metals
    • C22B34/10—Obtaining titanium, zirconium or hafnium
    • C22B34/12—Obtaining titanium or titanium compounds from ores or scrap by metallurgical processing; preparation of titanium compounds from other titanium compounds see C01G23/00 - C01G23/08
    • C22B34/1295—Refining, melting, remelting, working up of titanium
    • 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; Electric arc furnaces ; Tank furnaces
    • F27B3/04—Hearth-type furnaces, e.g. of reverberatory type; Electric arc furnaces ; Tank furnaces of multiple-hearth type; of multiple-chamber type; Combinations of hearth-type furnaces
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C2100/00—Exhaust gas
    • C21C2100/02—Treatment of the exhaust gas
    • 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
    • Y02P10/134—Reduction of greenhouse gas [GHG] emissions by avoiding CO2, e.g. using hydrogen

Definitions

  • the present invention relates to metallurgical reactors in which reaction intensities are substantially lower than those associated with popular so-called "high-intensity" bath smelting reactors, such as characteristic of basic oxygen steelmaking and emerging smelting reduction technologies for iron and steelmaking from primary and secondary metaliferous feeds, such as lump ores, ore fines, partly reduced ore and metal-containing waste streams.
  • high-intensity bath smelting reactors such as characteristic of basic oxygen steelmaking and emerging smelting reduction technologies for iron and steelmaking from primary and secondary metaliferous feeds, such as lump ores, ore fines, partly reduced ore and metal-containing waste streams.
  • the applicant has been promoting this alternative lower intensity technology for many years and, for example, has asserted at the Yazawa International Symposium (2003 TMS Annual Conference, San Diego U. S. A) that continuous steelmaking cannot sensibly be based on what Bessemer, himself, referred to as "a veritable volcano in state of active eruption.”
  • the emphasis in the present invention is directed not at the smelting reactions themselves, but rather at the transfer of thermal energy from so-called "post combustion gases" into the molten phases involved, whether that be an oxidic melt such as slag, molten metals or combinations of both, in order to secure the lowest possible energy route practically achievable on a large scale.
  • CCS carbon capture and storage
  • the present invention reassesses the role of melt circulation in high temperature pyrometallurgy and concludes that there are metallurgical processes, which benefit from forced circulation of both slag and metal phases independent of each other and opens up the possibility that radiative post combustion to an oxidic melt or slag phase can be an attractive proposition in certain circumstances, rather than universally an impediment as implied in description so far of prior art, in which forced circulation at relatively high rates has never previously been suggested.
  • the present invention takes co-ordinated steps to reduce the thermal resistance of the slag "film" to convective heat transfer, such that the temperature drop across the slag film is normally no more than about 5O 0 C and preferably considerably less by substantially increasing the forced circulation rate of the slag above that perhaps originally envisaged, if it can be demonstrated that overall process benefits accrue.
  • the magnitude of convective heat transfer from gas to melt is normally relatively small compared to the radiant energy flux in what the applicant has termed "swimming pool reactors" with large gas free board to ensure a mean beam length for gas radiation, commensurate with the thermal load to be satisfied.
  • the emissivity of combustion gases in an isothermal enclosure depends on the temperature and (pco2L) and (pmoL), where L is the mean beam length and the first term of each product is the partial pressure of CO 2 and H 2 O, respectively. Provision of adequate L, say in the region of 5 m for operation at 1 bar, is needed or proportionately less, if it is decided that operation above atmospheric pressure yields beneficial attributes commensurate with the additional cost.
  • transpiration of carbon monoxide gas across a porous carbon lining constituting the walls and ceiling of the reactor offers the required resistance to oxidation, whilst the exceptionally good mechanical and thermal shock properties of baked carbon or graphite at temperatures below about 2200 0 C and probably closer to the 2100 0 C level actually required for effective radiant post combustion to a melt with a surface temperature in the region of 1900 0 C or so in the preferred embodiment, ensure structural stability under the proposed very demanding conditions.
  • the general arrangement of the overall titanium manufacturing process based on carbothermic reduction of ilmenite is shown in Fig. 1, so that the relationship of radiative post combustion with other in-line processing steps is made clear from the outset.
  • the first of the in-line reactors is Smelting Reduction Reactor (SRRl), in which both the oxidic melt and metal phases are independently circulated to effect complete back-mixing of both so that unmelted shells of titanium oxycarbide at the solidus composition can be used for melt containment under virtually equilibrium conditions.
  • SRRl Smelting Reduction Reactor
  • SRRl may be optionally followed by a second melt circulation loop (SRR2), employed principally to increase the carbide content of the oxidic melt.
  • SRR2 second melt circulation loop
  • the next in-line melt circulation loop is for continuous vacuum refining (CVR) of the oxidic melt.
  • CVR continuous vacuum refining
  • the refined oxidic melt then proceeds to electrochemical deoxygenation to produce titanium metal, optionally preceded by a degree of carbide removal by controlled oxidation using CCVoxygen.
  • the oxidic melt containing titanium carbide forming essentially an ideal solution in a thermodynamic sense, is chlorinated to produce a very high- grade titanium tetrachloride of about 99.95% purity, if pigment manufacturers prefer to capitalise on their vast experience in making pigments via the vapour-phase oxidation route. Under these latter conditions, environmental problems associated with disposal of waste chlorides would be reduced by at least one order of magnitude, because of the high purity of the oxidic melt initially chlorinated.
  • radiative post combustion is conducted on both arms of the melt circulation loop constituting SRRl. Segregation of post combustion to a separate arm is not necessary in the present invention. Combining both smelting reduction and post combustion advantageously gives rise to a uniform flux of carbon monoxide gas rising from the surface of the oxidic melt into the gas phase above throughout the entire melt circulation loop. Reactor dimensions are carefully selected such that the carbon monoxide evolved flows upwards under laminar flow conditions. Post combustion eventually takes place by admission of a preheated mixture of recycled carbon dioxide and technically pure oxygen into the turbulent well-mixed zone immediately above the laminar flowing carbon monoxide.
  • the Reynolds number (Re) is less than say 2000-3000 in the laminar zone, while in the combustion zone turbulence is established by both increased mass flow rate as well as being beneficially promoted by the influence of the injected or otherwise admitted oxidant gas mixture and Re is typically above 5000.
  • Transpiration cooling is used to lower the temperature of the walls of combustors, internal components of advanced gas turbines, external surfaces of spacecraft and rockets on re-entry to the earth's atmosphere and the like, to enable available materials (metals or ceramics) to be used under extreme temperature conditions.
  • the present invention does not use transpiration to effect any cooling whatsoever.
  • cooling containment walls in radiative post combustion would be totally counterproductive and would encourage deposition of materials from the gas phase to form troublesome solid accretions.
  • the preferred embodiment uses transpiration of carbon monoxide gas through porous carbon walls merely to alter the mass transfer coefficient by imposing a bulk flow component in the opposite direction to the net molecular diffusion flux involving transport of oxidant from the post combustion gases towards the carbon or graphite walls and ceiling, in which radiative post combustion is carried out.
  • the fundamental processes involved are restricted to the gas boundary layer associated with the contacting of the solid with a bulk gas phase in motion. If any cooling does take place, this is co-incidental to the main objective.
  • the mass fluxes involved in the transpiration must be considerably lower than those associated with transpiration cooling, otherwise radiant heat transfer from the hot post combustion gases to the containment walls and ceiling would drastically reduce the thermal efficiency of radiative post combustion.
  • the first pre-requisite is to have relatively low intensity mass transfer conditions by employing planar surfaces and of course relatively low levels of turbulence. It is well known that small particles of carbon (soot) are oxidised by CO 2 at very high temperatures at rates controlled by chemical reaction kinetics and not by gaseous molecular diffusion. Similarly, academic studies, designed to eliminate the effects of gas diffusion, impinge high velocity gas jets onto solid carbon or melt surfaces to study interfacial chemical kinetics. It must be obvious that these situations and related phenomena have to be avoided in radiative post combustion. In the limit, high intensity eventually favours chemical rate control, but such conditions are rarely met in practical engineering applications and are therefore believed to be irrelevant to the present invention.
  • the oxidic melt comprised principally of titanium oxycarbide and a whole range of titanium oxides TiO, Ti 2 O 3 , Ti 2 O 5 and TiO 2 all in virtually thermodynamic equilibrium with each other, is force circulated at a high rate somewhere in the region of 1500 to 1 nominal melt circulation ratio based on equivalent TiO 2 in product melt, for reasons not immediately obvious, if radiative post combustion were being considered in isolation, which may pertain in other embodiments utilising the same generic principles, such as processes relating the continuous iron and steelmaking.
  • the new titanium metal technology demands temperatures, which are considerably higher that say 1400-1600 0 C, more representative of smelting reduction for steelmaking, for example.
  • the mole fraction of titanium carbide close to the liquidus temperature is typically between 0.1 and 0.15 at 1900 0 C, an operating temperature typical of SRRl in the preferred embodiment.
  • Titanium carbide has an exceptionally high thermal conductivity (k) of about 43 W/mK at 1900 0 C, so its presence even at the aforementioned level in the oxidic melt is bound to increase k above normal values for current industrial titania slags, whose effective k in the liquid state has been taken as 5 W/mK by Pistorius et al. (J. H. Zietsman and P. C. Pistorius: Minerals Engineering, 19, Issue 3, March 2006, 262-279) in modelling and ilmenite-smelting DC arc furnace process.
  • Pr Prandtl Number
  • Fig. 1 shows schematically the arrangement of two melt circulation reactors (SRRl and CVR) in which radiative post combustion is used to transmit thermal energy released in post combustion of smelting reduction gases.
  • a second melt circulation reactor (SRR2) for optionally increasing the carbide content of the melt in order to produce a higher-grade product in CVR is not shown.
  • Fig. 2 is a schematic sectional plan view of the first of the smelting reduction reactors (SRRl) showing the extensive flow area (rectangle abed) through which carbon monoxide produced by carbothermic reduction rises upwards.
  • SRRl smelting reduction reactors
  • Fig 3 is a schematic external plan view of the melt circulation loop reactor (SRRl) shown in Hg. 2.
  • Fig. 4 is a half-sectional elevation of the plan views in Fig. 2 and Fig. 3 of the melt circulation reactor (SRRl).
  • Fig. 5 is a sectional elevation taken across the width of the melt circulation loop (SRRl).
  • Fig. 1 the major portion of the thermal energy demand of the processes conducted in SRRl 3 SRR2 and CVR is satisfied by radiative post combustion. It can be shown quantitatively that for a plant producing 500,000 tonnes per annum of TiO 2 equivalent, SRRl requires two arms of a melt circulation loop, each arm being say 10m in width by about 50 m in length. For an oxidic melt depth of 0.5 m and an average velocity of 1.25 m/s, the oxidic melt flow is characterised by a Froude Number of less than unity, so the flow is sub-critical turbulent.
  • the temperature drop across the oxidic melt "liquid film" associated with convective heat transfer into the bulk of the circulating oxidic melt is evaluated to be less than 10 0 C.
  • the very low temperature drop of 10 0 C clearly demonstrates that the thermal resistance for convective transfer of heat into the bulk oxidic melt from the melt surface, receiving radiant energy input from post combustion, is negligible.
  • a brief statement concerning its evaluation is appropriate.
  • the radiative flux to the oxidic melt surface is estimated to be about 128 kW/m 2 for an oxidic melt at 1900 0 C and a combustion gas temperature of 2100 0 C.
  • the carbon walls 2 and ceiling, enclosing the radiative post combustion zone above the oxidic melt would be oxidised at a rate of 3.6 x 10 "6 kmol/s m 2 by combustion gases containing 85% by volume CO 2 and the balance principally CO.
  • the combustion gases, including recycled CO 2 as well as recycled but not transpired CO in this hypothetical case, flow upwards on each arm at an average velocity of about 0.24 m/s. Under these conditions, the bulk gas phase Re is about 12000, indicating that the flow upwards has progressed from initial laminar flow through transition to well- established turbulence.
  • the mean transpiration flux is about 1.6 x 10 "4 kmol/s m 2 .
  • the mass transfer coefficient for transport of CO 2 to the carbon surfaces is reduced drastically from about 1.14 x 10 "3 to 4.22 x 10 "5 m/s. For a graphite wall this corresponds to 25 mm depletion of graphite wall thickness per year.
  • the CO used for transpiration in this particular embodiment comprises CO released in electrochemical deoxygenation for titanium metal production, optionally CO released in association with lowering the carbide content of the oxidic melt in advance of deoxygenation and CO recovered from the vacuum system associated with CVR
  • These streams of CO represent significant thermal energy, so steps are taken to recover this as the streams are cooled, filtered and then compressed in preparation for preheating ahead of admission to the various faces of the walls 2 and ceiling all constructed from porous baked carbon or graphite.
  • Fig. 3 shown in section is a single baked carbon or graphite lined gas offtake 3, through which post combustion gases are ejected under the influence of a total pressure gradient by means of slot jets into the quench zone immediately above (not shown).
  • the hot gas off-takes 3 are designed 4 to be readily accessible and therefore easily replaceable employing standby units with consumable baked carbon or graphite linings 5 in place ready for immediate installation on a routine periodic basis.
  • the objective is to achieve partial quenching of the post combustion gases from a temperature in the region of 2100 0 C down to a lower temperature level, say 1300 0 C to 1200 0 C immediately they leave the upper region of the post combustion zone.
  • an axisymmetric jet of hot gas is formed, which is capable of entraining recycled cooled combustion gas, principally CO 2 at around 125 0 C, to effect cooling of the post combustion gases containing various elemental vapours and compounds without ever allowing the gases to contact solid surfaces and form accretions.
  • stable condensed dispersoids are formed in the bulk of the gas phase and quenched to a temperature level such that they are non-sticky and are entrained in the bulk gas, enabling the downstream use of conventional refractory lined gas off-take ducts.
  • Energy recovery from the off-gases now at about 1300 0 C is achieved by heat exchange using a moving packed bed regenerative preheater or similar device in order to raise the temperature of recycled CO 2 and technically pure oxygen to about 1200 0 C, before injection into the radiative post combustion zone.
  • This injected or otherwise added mixture of CO2 and O 2 promotes turbulence and supplies the oxidant for combustion of the evolved smelting reduction gases and CO associated with transpiration through the porous carbon walls and ceiling.
  • the partially quenched combustion gases still containing some CO, then become the carrier gas for fluid bed preheating of dried mineral concentrates, such as ilmenite under controlled oxygen potential conditions to say 1350 0 C to ensure removal of sulphur to very low levels in advance of feeding the preheated concentrate into SRRl .
  • Fig. 3 Also shown in Fig. 3 are the two rows of lances 6 and 7 for establishing the gas/liquid two- phase regions associated with independent forced circulation of both the oxidic melt and liquid metal phases, respectively. It is important to appreciate that these lances, which are submerged in the appropriate liquids, are withdrawn upwards in the event of a prolonged stoppage and melt freeze over. Normally, electrical conductive heating is employed to maintain the oxidic melt close to the liquidus temperature for shorter periods of times, such as involved in replacement of the consumable baked carbon or graphite-lined gas off-take from the post combustion zone. Referring now to Fig. 4 and Fig.
  • the gas off-take from the combustion zone is shown in half- section.
  • the initial internal dimensions of the off-take slot were 1.2 m wide x 10 m length, at the end of the tenth day, gas phase mass transfer controlled oxidation at 2100 0 C with 85% CO 2 at 15% CO by volume would enlarge the slot 4 to about 2.7 m wide x 11.5 m length, for example.
  • the carbon depletion rate is non-linear with respect to time and as the slot enlarges the carbon mass depletion rate progressively decreases.
  • the gas phase Re is about 125,000 and by the end of the tenth day this has decreased to 98,000 so the flow remains very turbulent over this period.
  • the carbon depletion cannot be allowed to continue indefinitely, because of the need to quench the post combustion gases 14 to a required lower temperature level by entraining recycled cooled combustion gas 15, principally CO 2 at around 125 0 C, within a specified distance before the slot jet impinges on solid surfaces 16 and forms accretions.
  • For an axisymmetric turbulent jet the extent of cooler gas entrainment was studied in the now classic work of Ricou and Spalding (F. D. Ricou and D. B. Spalding, J. Fluid Meek, 11, 1961, 21-32).
  • the concentrates are fluid bed preheated and then fed at 1350 0 C into SRRl, which is operated nominally at one bar pressure and 1900 0 C. Melt is over flown or otherwise removed from SRRl to SRR2, which operates at nominally one bar pressure at 2000 0 C, where the carbide concentration is increased to facilitate vacuum refining in CVR at 1920 0 C and at operating total pressure of 1 mbar.
  • the principal thermal demands are in SRRl, where a heat input of 612 MJ per kmol of TiO 2 equivalent is needed and CVR, where some 155 MJ per kmol TiO 2 equivalent is required.
  • SRR2 has been designed to have a relatively smaller thermal load of 55 MJ per kmol TiO 2 equivalent, because operation at 2000 0 C makes it more demanding to supply energy by radiative post combustion, if a maximum operating temperature of 2100 0 C or thereabouts is imposed so that structural graphite can be kept well below 2200 0 C 5 a conservative recommended upper temperature limit for engineering applications.
  • Carbon monoxide is exhausted from the CVR melt circulation loop under vacuum using a steam jet ejector system based on established steelmaking practise for oxygen top-blown circulating flow vacuum degassing of liquid steel.
  • An overall energy balance on the entire process indicates that the steam consumed by the ejector pumping system accounts for 60-70 per cent of the steam generated in waste heat recovery, leaving after allowing for other minor steam requirements, about 15-20 per cent available for on-site power generation, if so desired.
  • all the energy requirements associated with the smelting reduction and vacuum refining thermal loads are provided by radiative post combustion.
  • the door is open to titanium metal production, directly from ilmenite concentrates at an overall energy consumption about one third of the current best available technology employing the Kroll process.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Metallurgy (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Geology (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Environmental & Geological Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Manufacture And Refinement Of Metals (AREA)

Abstract

L'invention concerne une circulation forcée de matière fondue à la fois de la phase oxyde et de la phase métallique qui ouvre de façon indépendante la perspective d'un traitement continu jusqu'à 2200°C en utilisant des réacteurs en ligne en graphite. Au centre de la nouvelle technologie, on trouve une combustion de CO à base d'oxygène avec une radiation de gaz des zones de combustion vers des surfaces de matière en fusion totalement rétro-mélangées situées immédiatement en dessous, à partir desquelles du CO est uniformément dégagé, formant ainsi une couche de protection laminaire s'écoulant vers le haut, et ensuite une zone de combustion seulement modérément turbulente après l'ajout d'un oxydant. Les régions de paroi et de toit principales sont protégées en réduisant les valeurs déjà basses des coefficients de transfert de masse d'un facteur d'environ 30, en utilisant une transpiration de CO sous un gradient de pression total opposé à la direction du CO2 pour obtenir des durées de service de 1 à 5 ans. Les dégagements gazeux post-combustion sont refroidis par entraînement dans du CO2 recyclé en utilisant des jets turbulents axisymétriques sortant de fentes garnies de graphite, facilement accessibles et facilement remplaçables sur une base périodique routinière.
PCT/GB2007/000571 2006-08-11 2007-02-21 Post-combustion avec radiation Ceased WO2008017797A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB0615952A GB0615952D0 (en) 2006-08-11 2006-08-11 Radiative post combustion
GB0615952.9 2006-08-11

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WO2008017797A1 true WO2008017797A1 (fr) 2008-02-14

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB868717A (en) * 1956-05-25 1961-05-25 Union Carbide Corp Improvements in the treatment of ferro-titanium ores
DE1433293A1 (de) * 1964-10-16 1969-01-09 Air Liquide Kontinuierliches Verfahren zur Herstellung von Stahl aus Eisenerz
US5885325A (en) * 1994-12-20 1999-03-23 Usx Corporation Process and apparatus for the manufacture of steel
WO2004007775A2 (fr) * 2002-07-15 2004-01-22 Noel Alfred Warner Production directe de metaux et d'alliages affines
WO2005118890A2 (fr) * 2004-05-29 2005-12-15 Noel Warner Recuperation d'acier dans de la ferraille a trier

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB868717A (en) * 1956-05-25 1961-05-25 Union Carbide Corp Improvements in the treatment of ferro-titanium ores
DE1433293A1 (de) * 1964-10-16 1969-01-09 Air Liquide Kontinuierliches Verfahren zur Herstellung von Stahl aus Eisenerz
US5885325A (en) * 1994-12-20 1999-03-23 Usx Corporation Process and apparatus for the manufacture of steel
WO2004007775A2 (fr) * 2002-07-15 2004-01-22 Noel Alfred Warner Production directe de metaux et d'alliages affines
WO2005118890A2 (fr) * 2004-05-29 2005-12-15 Noel Warner Recuperation d'acier dans de la ferraille a trier

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