Effect of Heat Treating Temperature on Chemical and Physical Properties of Natural Hydroxyapatite Produced From Bovine Bone

This study focused on chemical and physical properties of Hydroxyapatite powder was prepared by burning bone and heat treating the obtained bone ash at different temperatures (600, 700, 800, and 1100 °C) in an air furnace. The black ash was converted to a white powder after heat treatment. Results of X-ray diffraction analysis and Fourier transform infra-red spectroscopy that were done on heat treated powders in different temperatures indicated that the white powder was hydroxyapatite and did not contain any organic components of the bone. Furthermore, results of X-ray diffraction analysis were shown that phase transformation of the resulted hydroxyapatite to other calcium phosphate phases did not occur up to 1100 °C. X-ray fluorescence analyses revealed that calcium and phosphorous were the main elements and magnesium and sodium were present as minor impurities. The results of the energy dispersive X-ray analysis showed that Ca/P ratio of this natural hydroxyapatite varies between 1.46 and 2.01. The resulted material was found to be thermally stable up to 1100 °C. The density of natural hydroxyapatite heat treated at 800 °C was measured to be 3.187 g/cm³.