The objectives at the forefront of this research are process optimization of fluidized-bed based technologies for iron- and steelmaking and the characterization of the process behavior of different globally traded iron ore brands. Direct reduction or smelting reduction technologies as an alternative to the traditional blast furnace process have been developed in recent years which can use iron ore fines directly without prior benefication processes. The reduction behavior of different iron ore fines were investigated by means of reduction tests and morphological characterization of the iron oxide phases in the iron ore. Tests were performed in a lab scale fluidized bed reactor and petrographical characteristics were investigated for the raw ore and reduced samples during and after the tests. The influence of process mode, residence time, pre-reduction temperature and gas composition for a sequenced fluidized bed reactor system on the reduction behavior of hematite ore was studied. Furthermore, the reduction behavior of different iron ore brands and their morphological evolution during the process could be characterized.