The X-ray powder diffraction (XRD) analysis of the synthesized HAp samples was done (Bruker
D-8 Advanced, Germany) in reflection mode with Cu Kα (λ=1.5405 Å) radiation. The data were
analyzed in the 2Ө range from 10º to 80º with a scanning step of 2º per min. The results reveal
that the thermal processing of CaO in the phosphate solution at 9500C produces a solid material
of white color with porous structure having pores of irregular diameter and high mechanical
strength. X-ray diffraction of this sample in Fig. 3 shows several phases. The crystalline phases
was identified as HAp (JCPDS, 9-0432), with some phases of calcium oxide (JCPD, 37-1497).
and calcium hydroxide (JCPDS,4-0733). These phases may be attributed to incomplete
transformation of calcite, resulting from interruption in supply of steam atmosphere at the high
temperature during reaction process.