Spectroscopic Analysis of Chemical Compounds Derived from the Calcination of Snail Shells Waste at Different Temperatures

Biogenic calcium carbonate (CaCO3) has attracted great attention in multiple applications. This study investigates the influence of different calcination temperatures (200-1000 degrees C) on the morphology and the structure of snail shells waste. The different chemical compounds obtained were characterized by scanning electron microscope (SEM), energy dispersive X-ray analyzer (EDXS), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and differential thermal analysis (DTA), Fourier transform infrared spectroscopy (FT-IR) and Raman spectroscopy (Raman). The identified particles for raw and calcined SSP at 200 degrees C were aragonite polymorphs, calcite for 400-600 degrees C and calcium oxide (CaO) for 800-1000 degrees C. The endothermic decomposition of the CaCO3 phase to CaO occurs in the temperature range of 668-870 degrees C. The transformation takes along with a loss of about 40% of the initial weight of the sample due to the CO2 release. Ca-OH bond was revealed in FT-IR spectra at calcination >= 700 degrees C. It was caused by the reaction of CaO with H2O in atmospheric air. The preparation of CaO from snail shells waste as the primary source is environmentally sustainable. Snail shells based CaO can potentially be exploited for various applications, especially for catalyst, wastewater treatment and biomedical.