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

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.