Moving-bed studies on reaction behavior of iron-ore and coal char mixtures in gasifying agents

Abstract

Coaction of coal/char gasification and iron ore reduction in ore-coal/char mixtures has been investigated using a novel moving bed technique (MBT) to study the effects of several parameters (such as ratio of ore to coal/char, heating rate and particle size) on gasification rate. The MBT is essentially a technique for controlled non-isothermal kinetic studies on relatively large samples. The MBT data have been compared with TGA data generated from gasification of coal/char by externally introduced carbon dioxide gas and coaction of coal/char gasification and iron-ore reduction. The results are interpreted in terms of metallic iron produced in situ and acting as a catalyst during CO2 gasification. The results indicate that MBT is a rapid and reliable means of measuring the reaction rate of a solid reaction mixture, namely reduction of iron-ore coupled with gasification of coal.