Modelling the reduction of an iron ore-coal composite pellet with conduction and convection in an axisymmetric temperature field

K e y w o r d s C o n t r o l volume, Iron ore direct reduction, Composite pellet, Axisymmetric heat transfer. 1. I N T R O D U C T I O N Some coal-based i ron ore direct reduc t ion processes are based on format ion of composi te pellets which consist of a mix ture of fines of i ron-bear ing oxide, carbonaceous mater ia l , for example, coal, coke, or char and a smal l a m o u n t of binder . Then , the pellets are placed on a ro ta ry hear th and the i ron ore is reduced to iron by chemical reactions. The nonun i f o r mi t y of heat ing, heterogeneous *Author to whom all correspondence should be addressed. This work is supported by the AustrMian Research Council under the Linkage scheme, with BHP-Billiton as the industrial partner. We are also grateful to a referee for the recommendation on the modification of the control volume section and pointing us to Zhang and Nguyen's papers. 0895-7177/05/$ see front matter @ 2005 Elsevier Ltd. All rights reserved. doi:10.1016/j.mcm.2005.05.014 Typeset by .AA/~S-TEX