Particle formation of hydroxyapatite precursor containing two components in a spray pyrolysis process

Abstract

The particle formation mechanism of hydroxyapatite precursor containing two components, Ca(OOCCH₃)₂ and (NH₄)₂HPO₄ with a ratio of Ca/P= 1.67, in a spray pyrolysis process has been studied by computational fluid dynamics (CFD) simulation on the transfer of heat and mass from droplets to the surrounding media. The focus included the evaporation of the solvent in the droplets, a second evaporation due to crust formation, the decomposition reaction of each component of the precursor, and a solid-state reaction that included the kinetic parameters of the precursor regarding its two components that formed the hydroxyapatite product. The rate of evaporation and the reacted fraction of the precursor both increased with temperature. The predicted average size of the hydroxyapatite particles agreed well with the experimental results. Therefore, the selected models were also suitable for predicting the average size of particles that contain two components in the precursor solution.

Keywords

droplet / hydroxyapatite particle / CFD / tubular furnace / spray pyrolysis

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Acknowledgments

Research Grant sponsored by the Directorate General for Higher Education, Ministry of Education and Culture of Indonesia for Institut Teknologi Sepuluh Nopember (Penelitian Strategis Nasional, Contract No. 10473/I2.7/PM/2009) is gratefully acknowledged.

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2014 Higher Education Press and Springer-Verlag Berlin Heidelberg