Chemical and Morphological Analysis of Calcium Oxide (CaO) Powder from Sea Urchin (Diadema setosum) Shell

Abstract

Calcium carbonate (CaCO3) has been taken from sea urchin (Diadema setosum) shell and calcinated at several temperatures to obtain calcium oxide (CaO). X-Ray Fluorescence Spectroscopy (XRF) revealed that the powder from this shell had a high Ca level, which increased at a higher temperature. Fourier Transform Infrared Spectroscopy (FTIR) spectra agreed to an increase in Ca level that showed the presence of CaO at 900 °C and 1100 °C; otherwise, CaCO3 disappeared. Using Scanning Electron Microscopy (SEM), the powder morphology was more homogeneous at 900 °C and 1100 °C than at lower temperatures. This morphology was encouraged by decreasing particle size, indicating compound decomposition in the powder and Ca leaved. This decomposition was confirmed by an Energy Dispersive X-ray Spectroscopy (EDS) analysis that showed increased Ca content with higher mass and atomic level at a higher temperature.