A Study of Kinetics and Mechanisms of Iron Ore Reduction in Ore/Coal Composites

Abstract

<p>For environmental and economical considerations, it is desirable to use iron ore concentrates directly without agglomeration and coal directly without coking for ironmaking. The present work is a study of the kinetics and mechanisms of iron ore reduction in ore/coal composites. An experimental system has been designed and experiments have been conducted with in-situ measurements of temperature and pressure to establish profiles within the ore/coal packing with the furnace temperature maintained at 1200 or 1300ºC. Samples were taken at various locations for chemical analysis in the partially reacted specimens. These experiments lead to a better understanding of this non-isothermal and non-isobaric system. A non-isothermal and non-isobaric mathematical model has been developed and validated by the experimental data. Mechanisms of heat transfer, mass transfer and interfacial reactions were studied using the mathematical model. The contribution of the individual kinetic steps to the rate of overall reaction were compared to evaluate the rate controlling step. The contribution of the author is the design of the experimental system which has demonstrated the non-isothermal and non-isobaric nature of the reaction system, and the development of the mathematical model. The present study may be used in new ironmaking processes and carbothermic process, such as FASTMET and cokemaking processes.</p>