Characterization of clays from the Fez area (northern Morocco) for potential uses in the ceramics industry

Abstract

Clays from the Saiss basin (Northern Morocco) used traditionally in the ceramic industry of Fez were studied by mineralogical and physico-chemical techniques in order to evaluate their potential suitability as raw materials for ceramic manufacture. X-ray diffraction (XRD) were used to determine the mineralogical composition. Physical properties were identified by particle size distribution and consistency limits. Chemical composition was carried out by XRF analysis and Fourier Transform-Infrared (FT-IR) spectrometry. The structural changes of mineral phases during firing in the raw materials have been studied with a range of temperature between 500 and 1000 °C. In the pottery site from Fez, the potters generally use a mixture of 25% of fine clay (ARFS) from the upper part of the Miocene marls deposit and 75% of sandy clay (ARFR) from lower level of Miocene marls. ARFS clay gives very rigid pieces after firing; they are difficult to handle with desired shapes and sizes by artisan potters. However, the pieces obtained with ARFR clay show signs of faltering. The mixture of these two clayey materials is therefore https://doi.org/10.1180/clm.2022.30 Published online by Cambridge University Press necessary for the optimal paste for ceramic proposes in this pottery site. The chemical compositions indicated that SiO 2 , Al 2 O 3, CaO and Fe 2 O 3 are major minerals, with small amounts of K 2 O and MgO. Quartz, feldspars and clay minerals prevail in all samples.Kaolinite, illite and smectite are the dominant clay mineral phases, with a trace of chlorite and interstratified. The classification of these samples using appropriate ternary diagrams showed that the proportions used in the mixture lead to a new material with adequate characteristics for the production of traditional ceramics.