Kinetics of smelting reduction of fluxed composite iron ore pellets

Kinetic studies on smelting reduction of unreduced fluxed composite pellets (FCP) and fluxed composite pre-reduced iron ore pellets (FCRIP) have been carried out in an induction furnace. The pellets are charged into the slag layer floating on the carbon saturated molten iron bath in a graphite cruci ble. The slag basicity was however varied such that it has the same value a s that of the pellets charged. The temperature of the slag is varied within the range of 1623K to 1823K for the pellets of basicity 2.0. Kinetic studi es show a mixed kinetic model of both diffusion and chemical reaction contr olled. While the smelting of FCRIP follows the model expressed as G(alpha) = 1-(2/3)(alpha) - (1-alpha)(2/3), the unreduced FCP pellets initially foll ow the diffusion controlled model of G(alpha) = alpha(2) followed by a chem ical reaction controlled first order model of -In(1-alpha) at the latter st ages of smelting reduction, where a denotes the degree of reduction. The ba sicity dependence on the kinetics is not very significant. Comparison of th e activation energy values explains that the smelting reduction with pre-re duced pellets seems to be a rather less energy intensive process.