Preparation of hydroxyapatite by neutralization at low temperature - influence of purity of the raw material

A method to prepare hydroxyapatite-Ca-10(PO4)(6)(OH)(2)-at low temperature is studied. This simple and non-polluting method consists in neutralizing a suspension of lime (Ca(OH)(2)) with a solution of orthophosphoric acid. Th e chemical and physical properties of the initial lime particles have a gre at influence on the quality of the hydroxyapatite produced. Several kinds o f lime were characterized by X-ray diffraction, infrared spectroscopy, scan ning electron microscopy, size analysis, specific surface area and chemical analysis and tested in this work. Among the impurities contained in the li me, magnesium ion shows a strong influence on the formation of hydroxyapati te. The stoichiometry of the hydroxyapatite precipitate and its purity once calcinated depend on the quality of the raw materials. (C) 1999 Elsevier S cience S.A. All rights reserved.