Abstract :
Edible clays from West Africa (Senegal, Cote dIvoire, Guinee) are characterized by XRD, IR, TGA and ICP. The major component is kaolinite and silica is the main impurity while illite is found in some of them. Kinetic analysis of salting out of Ca^2+ and Mg^2+ were studied by Ionic Chromatography in physicochemically simulated physiological mediums (SPM). Raw and heated (110 °C) materials have been studied. Cations releasing from both materials was higher for Ca^2+ than Mg^2+. Stomachal SPM (1 (less than) pH (less than) 2) is the most favourable to this behaviour. Cations exchange is the most probable process involving Na^+ (0.102 nm) (SPM) and Ca^2+ (0.100 nm), Mg^2+ (0.072 nm) (Clay).
