Behaviour of bone origin hydroxyapatite at elevated temperatures and in O2 and CO2 atmospheres

In the present work the behaviour of HAp extracted from pig bones at elevated temperatures up to 1000 °C in O2 and CO2 atmospheres has been studied. It has been found that CO2 atmosphere arrests HAp decomposition. Chemical analysis and infrared spectroscopy reveal that no free CaO appears and no decrease of CO3−2 group concentration occurs in the material calcined in CO2 atmosphere. In the O2 atmosphere at elevated temperatures, CaO and CO2 are emitted from the samples, although the remaining material retains the HAp structure as indicated by the X-ray diffraction.