J. Phys. IV France
Volume 123, March 2005
Page(s) 351 - 354

J. Phys. IV France 123 (2005) 351-354

DOI: 10.1051/jp4:2005123064

Study of the chemical mechanisms of the reaction of neutralization of calcium hydroxide by phosphoric acid

M. Elgadi, E. Mejdoubi, L.L. Elansari, A. Essaddek, S. Abouricha and A. Lamhamdi

Laboratoire de Chimie du Solide Minéral, Département de Chimie, Faculté des Sciences Université Mohamed I, Oujda, Maroc

Calcium phosphates reported in this study, are prepared following an acido-basic reaction between phosphoric acid and calcium hydroxide. These phosphates are the brushite, tricalcium phosphate, hydroxyapatite and oxygenated apatite. The follow-up of the reaction by infra-red spectroscopy of absorption showed that the alkaline pH of calcium hydroxide solution, favours the formation of carbonated apatite, at the start of the reaction. Following the addition of phosphoric acid, the pH becomes increasingly favourable to the formation of the desired phase. The insertion of molecular oxygen in the apatitic tunnel is carried out by the use of hydrogen peroxide. The molecular oxygen rate in the apatite is then determined by volumetric analysis.

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