Precipitation of stoichiometric apatitic tricalcium phosphate prepared by a continuous process

Abstract

Various stages of the continuous precipitation of a stoichiometric apatitic tricalcium phosphate (Ca : P =1.50) have been observed with increasing duration of precipitation, particularly during the first 3 h necessary for the reactor to reach a steady state. The results show that an amorphous Ca²⁺-deficient phosphate close to the composition of octacalcium phosphate is formed in the early minutes of precipitation, then, after hydrolysis, it is transformed into an apatitic phase which leads to a stoichiometric apatitic tricalcium phosphate.