Preparation of β-Ca3(PO4)2 bioceramic powder from calcium carbonate and phosphoric acid

When preparing β-tricalcium phosphate (β-TCP) with Ca(NO3)2 or Ca(OH)2 as the raw materials, because of the problem of filtering, it is difficult to industrialize traditional methods. In this paper, β-TCP was prepared with calcium carbonate and phosphoric acid. According to XRD spectrum, the precursor of this system is octacalcium phosphate (OCP) [Ca8H2(PO4)6 · 5H2O] instead of non-stoichiometric hydroxyapatite (HA) obtained from traditional methods, and thermodynamics mechanism of the reaction was also studied. The crystal β-TCP powders were obtained after the precursor had been calcined at 850-1150 °C for 2 h. SEM images showed that hardening could eliminate the reunion to a great extent, and obtain dispersive β-TCP powders with a particle diameter between 0.5 and 2.0 μm. The main advantages of this process over traditional methods are the fast reaction rate, the easy filtering, the fine particle size and the minimum impurity.