Structural Changes Occuring During the Direct Reduction of Attepe Iron Ore

Abstract

At present, most of the World's iron (over 95 %) is produced in blast furnaces where it is essential to use high grade coking coal which is in great demand, scarce and very expensive. In addition, the building of blast furnaces requires huge capital investments and because of their large sizes they are not flexible for limited operations. These led, since 1950s to the development of direct reduction processes which have reached a worldwide production of 60 million tons per annum. The iron produced by direct reduction can be used directly as raw material in electric arc furnaces as a replacement of scrap, thus increasing the steel quality. The fact that Turkey imports around 15 million tons of scrap per year for steel production, indicates alone the importance of investigation of suitability of domestic iron ores to the direct reduction. Since the direct reduction processes involve typical gas-solid reactions, the structure of iron ore and structural changes taking place during reaction within the solid phase, have great impact on process kinetics. This study therefore, deals with the changes observed before (i.e. during preheating) and during reduction in the surface area and porosity of Attepe iron ore.

Keywords

• Direkt İndirgenme, Gaz-Katı Reaksiyonları, Porozite, BET yüzey alanı.