Phase transformation characterization of olivine subjected to high temperature in air

Olivine is one of the well-suited materials for fluidized bed reactor technology. After calcination at high temperature, olivine undergoes phase transformations resulting in dehydration and oxidation of fayalite to hematite and magnetite. The transformation mechanisms of olivine subjected to a calcination process at 1400 °C for 4 h are studied. Calcined olivine is characterized by X-Ray Diffraction (XRD), in situ XRD at varying temperatures and Raman spectroscopy. This paper explains the contribution of Raman spectroscopy to the study of iron oxide with regard to XRD. The heterogeneous distribution of hematite, magnetite and forsterite in the calcined material is exhibited by Raman mapping.