Chemical and structural characterization of natural phosphate of Hahotoe (Togo)

Gado Tchangbeddji; Gnande Djeteli; Koffi Ani Kili; Jean Michel Savariault; Jean Louis Lacout

doi:10.4314/bcse.v17i2.61659

Gado Tchangbeddji Laboratoire de Physico-Chimie des Matériaux, Faculté des Sciences Université de Lomé, BP 1515, Lomé, Togo
Gnande Djeteli Laboratoire de Physico-Chimie des Matériaux, Faculté des Sciences Université de Lomé, BP 1515, Lomé, Togo
Koffi Ani Kili Laboratoire de Physico-Chimie des Matériaux, Faculté des Sciences Université de Lomé, BP 1515, Lomé, Togo
Jean Michel Savariault Centre d'Elaboration de Matériaux et d'Etudes Structurales, CNRS, BP 4247, F-31055 Toulouse Cedex 4, France
Jean Louis Lacout CIRIMAT Equipe Physico-Chimie des Phosphates ENSIACET INP TOULOUSE, 118 route de Narbonne 31077 Toulouse Cedex 4, France

DOI: 10.4314/bcse.v17i2.61659

Keywords: Natural phosphate, Fluoroapatite, Infrared, X-Ray diffraction, Rietveld structure refinement

Abstract

Chemical and structural characterizations of natural phosphates of Hahotoe (Togo) have been performed. From chemical analysis and FTIR study, it can be concluded that the material is carbonated fluoroapatite with poor substitution of calcium by cadmium and manganese. From these results, the molecular formula proposed is:

Ca_9.925Cd_0.004Mn_0.013[(PO₄)_5.886(CO₃)_0.113]F₂.

Powder X-ray diffraction fitting results confirm that compound belongs to the apatite family crystallising in the hexagonal system, space group P6₃/m. The cell parameters are: a = 9.3547(5) Å; c = 6.8929(4) Å.

KEY WORDS: Natural phosphate, Fluoroapatite, Infrared, X-Ray diffraction, Rietveld structure refinement

Bull. Chem. Soc. Ethiop. 2003, 17(2), 139-146.

Chemical and structural characterization of natural phosphate of Hahotoe (Togo)

Abstract

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