Carbothermic reduction kinetics of nanocrystallite Fe2O3/NiO composites for the production of Fe/Ni alloy

Nanocrystalline Fe-Ni alloy has been fabricated by reduction of Fe2O3/NiO composite materials with solid carbon. Nanocrystalline compacts of pure and 26% NiO doped iron oxide were reduced at 800-1100 degrees C by solid carbon. The reduction behavior was investigated using advanced quadrupole mass spectrometer. XRD, SEM and TEM analysis were used to characterize the reduced samples. The aim of work is to clarify the reduction behavior of Fe2O3/NiO composite materials with solid carbon which is an important step for production of nanocrystalline Fe-Ni alloys. The influence of reduction conditions on the structural characteristics of the products was extensively studied to get clear comprehension of reduction process. It was found that the reduction rate increases with temperature. The experimental measurements were used to elucidate the carbothermic reduction mechanism of iron oxide doped with NiO. The reactions proceeded in a stepwise manner and Boudouard reaction is the major controlling step particularly at low temperatures whereas more contribution to solid state reaction control seems to have an effect at high temperatures. (C) 2008 Elsevier B.V. All rights reserved.