Study of the calcination temperature in samples of calcium phosphate synthesized by the method of direct way

The use of phosphates in bioceramics have attracted the interest of many researchers, especially when it is in the Ca / P = 1.67, which allows the obtention of the hydroxyapatite. This work aims to investigate different calcination temperatures on the structural and morphological characteristics of samples of calcium phosphates synthesized by the method of direct way, aiming for hydroxyapatite as a major phase. For this purpose, we used the calcium hydroxide and phosphoric acid in the Ca / P = 1.67. The samples were calcined at temperatures of 600, 700, 800, 900, 1000, 1100, 1200 and 1350°C/2h, and characterized by XRD, FTIR and Size Distribution. The XRD showed that 600-800°C, the major phase is the tricalcium phosphate, 900-1100°C, there is a phase calcium pyrophosphate. And at 1200 and 1350 ° C, there is a phase monetite. The infrared spectrum showed the characteristic vibrations of calcium phosphates in all conditions studied. It was observed from the results of FTIR presence of bands of the P-OH group and HPO₄^2-, PO₄³, for all temperatures studied. The highest average size of agglomerates of 108.05 mM was observed for the temperature of 1100 ° C. (author)