The influence of magnesium oxide on natural fluorapatite decomposition during the preparation of ye'elimite-spinel based multi-phase composites

This study investigates the development of compounds based on ye'elimite-spinel, which incorporates magnesium oxide (MgO) and fluorapatite. Utilizing natural fluorapatite as a raw material not only provides a cost-effective source of calcium oxide but also reduces the dependency on limestone, thereby decreasing CO₂ emissions linked to decarbonization. This research presents an in-depth analysis of the sintering behavior and phase transformations of ceramic materials. Techniques such as X-Ray diffraction (XRD), Rietveld method, SEM-EDS, FT-IR, and TG/DTG were employed to explore the effects of temperature (ranging from 1000 to 1500 °C) and varying MgO content (0–6 wt%) on phase formation, including fluorapatite, ye'elimite, spinel, and other high-temperature phases like hibonite, beta-tricalcium phosphate, and grossite. These findings indicate that increasing MgO content promotes the formation of spinel while stabilizing ye'elimite at higher temperatures. The results provide valuable insights for optimizing the composition and thermal properties of these composites for high-temperature applications, such as cements, refractories, and advanced ceramics.