Interrelation between kinetics of reduction and volume change during formation of directly reduced iron rod

Abstract

A kinetic study on reduction has been carried out by heating a central column of blue dust (a fine variety of iron ore) surrounded by a concentric layer of non‐coking coal fines in the temperature range of 1173‐ 1323 K. The temperature of the periphery of blue dust column is kept constant at the temperature of experimentation, however, the temperature of the interior of the cylindrical column increases with time of residence and the change in volume of the reaction mass occurs. The loose column of blue dust gets reduced, consolidated and sintered to produce directly reduced iron rod (DRIR). The work also comprises studies concerning the effect of volume change on the reduction kinetics. The reduction phenomena are very much influenced by the change in volume of reaction mass. The kinetics of reduction shows an agreement with Ginstling‐Brounshtein model whereas the kinetics of change in volume is interpreted using Johnson‐Mehl equation. The rate constants k1 and k2 derived from kinetic analysis of reduction and volume change respectively are shown to be linearly interrelated till the change in volume with respect to the original volume becomes more or less constant.