Preparation and characterization of anorthite and hydroxyapatite from Algerian Kaolin and natural phosphate
Résumé
Different composite materials were prepared using kaolin (DD2) and natural phosphate. Several mixtures were used by varying the kaolin content from 20 to 80 mass %. All powders were mixed and grounded by ball milling and then pressed in cylindrical form. Finally, the green samples were sintered between 1273 and 1673 K for 2 h under static air. Reactions and phase transformations of the powder sintering were studied by BET, thermal techniques (DTA/TG), X-ray diffraction, infrared spectroscopy (FT-IR), dilatometry and SEM analysis. The DTA/TG analysis and dilatometric curves showed some microstructure transformations in these mixtures. From the X-ray diffractograms, we put in evidence the formation of several composites such as: anorthite–Hap-β-TCP, anorthite–Hap, Hap–anorthite, anorthite and anorthite–mullite. The presence of the different composites was confirmed by micrographic observations.