Hydroxyapatite bio-ceramic powder was synthesized using waste eggshells as calcium source by
a straight forward thermal method. The process is carried out at high temperature. Different
calcium phosphate phases were obtained just by changing the thermal treatment. HAp is the only
apatite present in the reaction products, along with minute fractions of other calcium
compounds. The final product was characterized by X-ray diffraction, Scanning electron
microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FT-IR). Thermal analysis
(TG–DTA) was carried out to investigate the thermal stability of HAp.