The Ternary System H₃PO₄– Ca(OH)₂–H₂O Isotherms at 15 and 45 °C
Pages 76-81
K. Labgairi, A. Jourani and M. Kaddami

DOI: http://dx.doi.org/10.6000/1929-5030.2016.05.02.3

Published: 30 May 2016

Abstract: The solid–liquid phase equilibria of the system H₃PO₄– Ca(OH)₂–H₂O were studied under air pressure using a synthetic method based on conductivity measurements. Two isotherms at 15 and 45 °C were completely defined. The stable solid phases which appear in this range of temperature are hydroxyapatite (Ca₁₀(PO₄)₆(OH)₂), calcium hydrogen phosphate dihydrate (CaHPO₄.2H₂O), calcium hydrogen phosphate anhydrous (CaHPO₄) and calcium dihydrogen phosphate monohydrate (Ca(H₂PO₄)₂.H₂O). These solid phases were characterized using X ray diffraction.