Investigations were undertaken to assess the thermal modification in clay products from the Triassic deposit (Southeast Tunisia), in order to use them in ceramic products. That is why the study had recourse to several quantitative and qualitative techniques of analysis; chemical analysis, a mineralogical study, thermal analyses and analyses of geotechnical traits. The geotechnical characterization was carried out on a representative mixture of Triassic clay. The samples were dry pressed on clay bodies and sintered at temperatures ranging from 850 to 1150 degrees C. XRD and SEM were used to identify the phases present and the densification level. The relationship between water absorption, shrinkage and resistance to inflection as a function of the firing temperature was examined in order to enhance the quality of the final products and to optimize the production process. The results revealed that sintering is governed by different mechanisms according to the temperature. The neomineralization processes were investigated principally by X-ray diffraction. At the end of this study one can affirm that these clays have qualities necessary for the manufacture of traditional ceramic products.

Keywords: Tunisian clay; ceramic; thermal analysis; firing