Phase evolution and microstructural characterization of sintered ceramic bodies from contaminated marine sediments

Abstract

The phase evolution during firing of ceramic bodies from three different contaminated marine sediments was investigated as a function of temperature. The mineralogical evolution examined by X-ray diffraction (XRD) revealed that quartz, which is a main crystalline phase in the original marine sediments, remains as a main phase in the sintered bodies. In addition, a glassy phase and new crystalline phases appear as result of different chemical reactions during firing. Scanning electron microscopy (SEM) showed a homogeneous microstructure composed by pores, crystals and a ceramic matrix. Energy X-ray dispersive spectroscopy (EDS) analyses permitted to distinguish the crystalline phases previously identified by XRD and also minor phases, which were not detected in the X-ray diffractograms.