Physico-chemical characterization of clay raw materials from the Thicky quarry (Senegal) for the manufacture of earth bricks

This study focuses on the physico-chemical characterization of the clayey raw materials of the Thicky quarry. We made a geotechnical, mineralogical, chemical and microscopic study of the laterite and the Thicky clay. Mineralogical analysis by X-ray diffraction (XRD) reveals that our clay consists mainly of quartz (Q), kaolinite (K), illite (I) and calcite (C) while laterite consists of quartz (Q), kaolinite (K), hematite (H) and calcite (C). The results of the chemical composition show the presence of SiO2, Al2O3 and Fe2O3 in large quantities and also K2O, CaO, MgO, Na2O, TiO2 and P2O5 in small quantities in our materials. Infrared spectroscopy reveals the presence of relatively broad absorption bands located around 3500 cm-1 which are related to phyllosilicates such as kaolinite or illite. Microscopic observation of clay and laterite samples shows that the texture is relatively compact, formed of several superimposed planar sheets with turbostratic disorder. The results obtained show that these clayey raw materials are poor in organic matter and calcium carbonates so they can be used for the manufacture of earth bricks.