The crystallization of natural phosphate (Apatite) depend on the temperature and the liberation of cao

Synthesizing apatite crystals has become an important research subject in recent years. There is a vast potential for applications in various fields due to multiple ions substitution in apatite structure. In this study, the phases developed in apatite, which exists in naturally formed apatite in Mazıdağı (Mardin) region of Turkey, were examined via single and double-step sintering at critical temperatures determined by thermal analyses. Determination of liberation temperature between apatite and CaO, and removal of impurities through washing was aimed via examining the changes in the structure of the phases. Thermal, mineralogical, optical, microstructural and molecular properties of apatite were determined. The crystallinity, crystallite size and lattice parameters were calculated via sintering at temperatures specified by thermal analyses. According to the results, natural apatite has plate-shape with agglomerated spherical grains. Apatite consisting 28% P2O5 is a valuable raw material for ceramic materials. Apatite contains A and B-type carbonated structure associated with apatite bearing chlorine, fluorine and hydroxyl. Calcite and quartz exist as gang minerals with apatite. The crystallinity of apatite is 0,78 with a-axis 9,363Å and c-axis 6,878Å. The peaks of distinctive (211) and (112) planes of apatite emerge after sintering above 850°C. Apatite exhibits expansion at temperatures above 1085°C. As a result, higher relative density can be achieved by sintering under pressure instead of solid state sintering. Apatite has the highest crystallinity with 0,92 at 1085°C. 20µm rod-shaped crystals were determined in sintered apatite at 1150°C. Aspect ratio of the crystals was measured as 7-10:1. Lattice parameters decrease while the crystallinity increases 10% after sintering. Apatite washed has a-axis 9,31-9,39Å and c-axis 6,85-6,91Å. The calcite separated by floating has a-axis 5Å and c-axis 17Å. It is determined that, calcite bound with apatite can be separated after sintering followed by washing in CaO structure.