Kann mir jemand Seiten empfehlen die das Corex-Verfahren gut beschreiben? Ich bin bei meinen bisherigen Rescherchen auf eineige seiten gestoßen doch diese haben nicht die Infos enthalten die ich bräuchte. Infos die ich benötige z.B: Schema einer Anlage die das Corexvefahren betreibt[ RI-Schema].
Alichimist
08.08.2004, 16:15
The Corex process is designed to operate under elevated pressure, up to 0.5 MPa.
Coal is fed into the gasifier (a) where it comes into contact with a reducing gas atmosphere at a temperature of ca. 1000 – 1100 °C. Instantaneous drying and degasification of the coal particles occur in this upper portion of the melter –gasifier. Reducing gas is generated in a fluidized bed, by the partial oxidation of coal. At first carbon is oxidized to carbon dioxide. Then, carbon dioxide reacts with free carbon to form carbon monoxide. The gas temperature in the fluidized bed is in the range of 1600 – 1700 °C. The temperature conditions in the freeboard zone above the fluidized bed guarantee production of a high-quality reducing gas which contains ca. 65 – 70 % carbon monoxide, 20 – 25 % hydrogen, and 2 – 4 % carbon dioxide. The remaining constituents are methane, nitrogen and steam.
After leaving the melter – gasifier, the hot gas is mixed with cooling gas to obtain a temperature suitable for direct reduction, ca. 850 – 900 °C. The gas is then cleaned in hot cyclones (d) and fed to the shaft furnace as reducing gas. A small amount of the cleaned gas is converted to cooling gas in a gas cooler. The fines captured in the hot cyclone are reinjected into the melter – gasifier.
The reducing gas is fed into the reduction furnace and countercurrently ascends through the iron burden.
The iron ore, charged into the shaft furnace through a lock hopper system, descends by gravity. The reduction reaction in the shaft furnace, using gas with ca. 70 % carbon monoxide and 25 % hydrogen is exothermic, leading to temperatures in the burden which are above the reducing gas temperature. Because of carbon monoxide decomposition, carbon deposits will form on the iron and act as a lubricant. Formation of Fe3C occurs as well and cluster formation is avoided. The top gas is cleaned and cooled in a scrubber, and is then available for various purposes. Metallization of the DRI averages 90 – 95 %, and its carbon content is in the range of 3 – 5 %, depending on the raw material used and operating conditions.
anbei ein Anlagenschema: