Compacts of pure Fe
2O
3 and Fe
2O
3-doped with either of 1.0 % CaO and/or 1.0 % MgO, sintered at 1473 K for 20 h, were isothermally reduced at 1173-1473 K with 10%CO-90%CO
2 to magnetite then to metallic iron with purified CO. The oxygen weight-loss resulted from Fe
2O
3-Fe
3O
4 or Fe
3O
4-Fe reduction steps was continuously recorded as a function of time. Chemical and X-ray analyses, microscope examination and pore size analyzer were used to characterize the fired and reduced compacts. The influence of CaO and/or MgO on the reduction behaviour of Fe
2O
3 and Fe
3O
4 was intensively studied. The reduction mechanisms predicted from both of apparent activation energy values and heterogeneous gas-solid mathematical models were correlated with the microstructures of partially reduced samples. The results obtained showed that the doping of these fluxing oxides promoted the reduction of Fe
2O
3 at 1173-1473 K. The reduction of pure and doped Fe
2O
3 compacts is controlled by gaseous diffusion at early stages and by interfacial chemical reaction at later stages. In Fe
3O
4-Fe reduction step, the doping of CaO and/or MgO enhanced the reduction at early stages which is temperature and compact composition dependent. With progress in reduction, the presence of MgO retarded the reduction of Fe
3O
4 at ≤1273 K resulting a slowing down in the rate at latter stages. This was attributed to formation of entrapped lower oxide relics which hindered gaseous diffusion. At early stages, the reduction of pure and doped Fe
3O
4 compacts is controlled by mixed control reaction mechanism. At latter stages, interfacial chemical reaction is the rate determining step for pure and CaO-containing samples, whereas solid-state diffusion is the rate controlling step for MgO-doped compacts.
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