Mineralogical, Physico-chemical and Geochemical Characterization of Three Kaolinitic Clays (Ne Algeria): Comparative Study

Abstract Forteen clay samples collected from three kaolin deposits (Tamazert, Hadj Ali and Chekfa; NE Algeria) are characterized by several techniques in order to compares them to somes kaolins used in industry especially that used in ceramics. All the samples were investigated by X-ray diffraction, Infrared absorption spectroscopy, thermal analysis (TG), plasticity, environmental scanning electron microscopy and chemical major elements analysis. The bulk mineralogical composition of all clays samples is dominated by kaolinite (21-75%), illite/ muscovite (33-76%) and quartz (7-21%). K-feldspar and plagioclase are only present in Chekfa and Hadj Ali clays with small amounts. Clay fraction (< 2µm) dominated by kaolinite and illite (98%). Chlorite and smectite are present in some samples of Chekfa and Hadj Ali clays with insignificant amount (˂1%). The particles-size distribution of all samples showed the abundance of sandy silt fraction (28-63%) and silty sand (39-64%) with moderate clayey fraction (2-7%). The chemical composition showed variable amounts of SiO2 (59-68%), Al2O3 (18-39%), Fe2O3 (.26-1.38%) and TiO2 (0.34-0.69%) in accordance with the free quartz in all studied samples. Plasticity-index (7.5-7.9%), Specific surface (28-47m2) and Cation exchange (5-11meq/100g) values are moderate in all samples. Given these properties, these clays may be suitable in bricks and ceramic product.