Abstract
During preparation, the synthesis of magnesium pyrophosphate or orthophosphate is strongly affected by the nature of both starting materials and precipitating agents. Also the stoichiometry of reactants influences on the structure and composition of prepared samples. Several magnesium phosphate samples were prepared at room temperature as Mg3(PO4)2·22H2O, MgHPO4·3H2O, NH4MgPO4·H2O and NH4MgPO4·6H2O. After calcinations of these samples at 850 °C for 6 h, MgHPO4·3H2O, NH4MgPO4·H2O and NH4MgPO4·6H2O were converted to pyrophosphates (α-Mg2P2O7). But Mg3(PO4)2·22H2O converted to orthophosphate. The obtained solids were investigated as synthesized or after calcinations by various physicochemical techniques as X-ray diffraction (XRD), thermogravemetric analysis (TGA) and differential thermal analysis (DTA). IR spectroscopy was used for only calcined samples.
