Pellet phase changes during reduced iron production by rotary kiln process

Magnetite concentrates from eastern Serbia have the potential to be processed into reduced iron pellets that can be used in the iron and steel industry. This paper investigates the reducibility and crushing strength of pellets made from these concentrates, reduced to iron in a rotary kiln using coal (anthracite and brown lignite) as an external solid reductant, based on the observed phase changes. The phase changes were investigated by chemical analysis, microscopic analysis, X-ray diffraction and electron microanalysis. The dependences of the phase changes on the degree of reduction, as well as on reduction time and temperature, were determined. Also, the dependences of the volume change and compression strength of pellets on reduction temperature were determined.