Statistical analysis of apatitic tricalcium phosphate preparation

Abstract

Apatitic tricalcium phosphate was obtained by a continuous (3–5 kg per 24 h) process using the conventional double decomposition method between an aqueous calcium nitrate solution, Ca(NO₃)₂, and an aqueous ammonium phosphate solution, (NH₄)₂HPO₄. To check the effect of certain variables on the reaction, a fractional central composite design was set up taking six variables into account: pH, (Ca/P)_reagents, concentration of the calcium nitrate solution ([Ca²⁺]), temperature (T), duration of precipitation (R) and speed of stirring (S). The limiting factors of precipitation for apatitic tricalcium phosphate are discussed.