Mineralogy and firing characteristics of clayey materials used for ceramic purposes from ! Sale region (Morocco)

Clayey marls from the Bouregreg basin (Morocco) used traditionally in the ceramic industry of Sale were studied by mineralogical and physico-chemical characterization in order to evaluate their potential suitability as raw materials in ceramic applications. X-ray diffraction (XRD) and Fourier Transform-Infrared (FT-IR) spectrometry are used to establish the mineralogical composition. Physical properties were identified by particle size distribution and consistency limits. Chemical composition was carried out by XRF technique. The clay suitability for traditional ceramics was discussed in view of its granulometric distribution, plasticity and thermal behavior. Two clay materials, 75% of upper Miocene marl (ARSNS) and 25% of Triassic clay (ARSNI), are used for the manufacture of utility ceramics in Sale region, the first rich in carbonates (20% of CaO) and the second non-calcareous. The chemical compositions indicated that Si_O2, Al_2O_3 and Fe_2O_3 are major elements while K_2O and MgO are less abundant. Quartz, Feldspar and clay minerals prevail in all samples, with kaolinite, illite and smectite being the dominant phases. The classification of these samples using appropriate ternary diagrams showed that the proportions used in the mixture lead to a new material (ARSM) with adequate characteristics for the production of traditional ceramics.