STATISTICAL-ANALYSIS OF APATITIC TRICALCIUM PHOSPHATE PREPARATION

Apatitic tricalcium phosphate was obtained by a continuous (3-5 kg per 24 h) process using the conventional double decomposition method betw een an aqueous calcium nitrate solution, Ca(NO3)2, and an aqueous ammo nium phosphate solution, (NH4)2HPO4. To check the effect of certain va riables on the reaction, a fractional central composite design was set up taking six variables into account: pH, (Ca/P)reagents, concentrati on 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.