摘要:
A process for at least partially reducing iron oxides comprises forming a bed of reactants on a hearth of a rotary hearth furnace, the reactants comprising (a) mixture of iron ore fines and particulate carbonaceous material and/or (b) micro-agglomerates of iron ore fines and particulate carbonaceous material. The mixture and/or the micro-agglomerates are heated in the rotary hearth furnace to at least reduce the iron oxides. The "micro-agglomerates" are agglomerates that are less than 1400 microns (and preferably more than 500 microns) in diameter. The at least partially reduced product is preferably used in the production of metallic iron. An apparatus for at least partially reducing iron oxides is also claimed. The process permits operation of the rotary hearth furnace without requiring pelletisation of iron oxide fines and coal.
摘要:
Apparatus (10) for preheating self-reducing pellets for direct use in ironmaking or steelmaking in which a preheat chamber (14) contains the pellets and is primarily externally heated using waste exhaust gases and secondarily heated directly by using an internal preheat burner (24). The preheat chamber gases are vented into the external heating chamber (26) where any CO present is post-combusted to produce CO2 with the energy from the post-combustion used to contribute to external heating of the preheat chamber (14).
摘要:
Solid state iron oxide reduction in a gas-solid reduction zone is combined with continuous melting of the hot solid reduced iron in a fuel-fired gas-solid-liquid melting zone within a rotary furnace. The process includes direct pneumatic transfer of the hot reduced iron by carrier gases through a transfer duct incorporating an injection lance nozzle projecting a jet of hot reduced iron downwards into the metal bath within the melting zone. Oxygen is also introduced into the hot gas stream at selected locations in the melting zone for post-combustion with carbon monoxide generated by a carbon boil and combustion with other combustible gases prior to exit from the rotary furnace, thereby furnishing heat for melting. The hot gas stream is then utilized to provide a significant part of the heat requirement for reduction, prior to exhausting into the atmosphere.
摘要:
Raw materials, including a metal oxide and a carbonaceous material, are supplied into a rotary hearth furnace. Then, the raw materials are heated and reduced by burners, which are arranged to cause a strong stirring action for an atmosphere around the raw materials, in an early reducing period that is defined as a period during which 70 - 80 % of a total amount of a flammable gas generated from the raw materials is generated. In a latter period subsequent to the early reducing period, the raw materials are heated and reduced by burners arranged to cause a weak stirring action for an atmosphere around the raw materials, whereby a metal is manufactured. With the present invention, productivity can be improved and the fuel consumption per unit product can be reduced.
摘要:
Method for the pyrometallurgical treatment of iron oxides and/or zinc oxides and/or heavy metals, such as those contained in the fumes of electric arc furnaces, whereby the oxides and possibly the heavy metals are fed into a rotary furnace (21) so as to obtain oxides of heavy metals and/or cast-iron, the oxides being collected (34) and sent to a distillation furnace (67), whence the heavy metals are obtained in the liquid state.
摘要:
Der Eisenschwamm wird durch Direktreduktion von eisenoxidhaltigen Materialien mittels fester kohlenstoffhaltiger Reduktionsmittel in einem Drehrohrofen erzeugt, wobei der Austrag des Drehrohrofens in Eisenschwamm und überschüssigen Kohlenstoff enthaltendes Material getrennt wird, das Kohlenstoff enthaltende Material in einem Wirbelschichtreaktor mit zirkulierender Wirbelschicht verbrannt wird, und die erzeugte Verbrennungswärme abgeführt und zur Erzeugung von elektrischer Energie verwendet wird. Zur Ausnutzung der überschüssigen Energien des Drehrohrofenprozesses und Verminderung des Anfalles an SO 2 , NO X und CaS wird das staubhaltige Abgas des Drehrohrofens in den Wirbelschichtreaktor geleitet und dort nachverbrannt, mindestens der überwiegende Teil des gesamten in den Wirbelschichtreaktor eingeführten sauerstoffhaltigen Gases als Fluidisierungsgas in den unteren Bereich des Wirbelschichtreaktors eingeleitet, die Verbrennung der brennbaren Bestandteile mit einem überstöchiometrischen Sauerstoffgehalt durchgeführt, und die mit den Gasen aus dem Wirbelschichtreaktor ausgetragenen Feststoffe derart in den Wirbelschichtreaktor zurückgeleitet, dass der stündliche Feststoffumlauf mindestens das 5-fache des im Wirbelschichtreaktor befindlichen Feststoffgewichts ausmacht.