A Mathematic Model for the Reduction of Iron Ore in a Moving Bed

A one-dimensional mathematical modei was developed for describing a moving bed reactor in which iron oxide pellets are reduced to me ta 1 lie iron with hydrogen and/or carbon monoxide in a counter-current flow a-rrangement.The model uses the "three-interface shringking core model" as the expression of single-pellet reaction kinetics.The model consists of the reaction rate equations of iron oxides and the heat and mass balance equations for both of the gas and the solid streams.The model shows the longitudinal distribution of the process variables such as degree of pellets recuction,and composition,pressure as well as temperature of the gas stream.
For the purpose of investigating the reduction process of pellets in a moving bed and checking the correctness of the model, a bench-scale moving bed reactor was established. The experiments were carrieb out until the steady state was reached.The calculating results based on the model s-how reasonable agreement with the experimental measurements.The model can be used for describing an industrial shaft furnace,and shows a difference characteristic between the reduction process of iron ore in a shaft furnace and the reduction process of iron ore under fixed conditions in laboratory.