Mineralogical evaluation and industrial applications of the Triassic clay deposits, Southern Tunisia

This study deals with the mineralogical and thermal analysis of Triassic clays in the south-Eastern Tunisia (Medenine area) in order to use them in the faience ceramic. That is why the study had recourse to several quantitative and qualitative research instruments: chemical analysis, mineralogical study, thermal analyses and analyses of geotechnical traits. The data collected from these techniques show that illite and kaolinite are the major clay phases. The accessory minerals detected in powdered rock are; quartz, dolomite and hematite.Geotechnical characterization was carried out on the three representative mixtures of Triassic clay samples. Each mixture is fired at three different temperatures 850,900 and 950 °C. Firing characteristics (shrinkage, water absorption, and mechanical resistance to the inflection) were measured and 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 faience ceramic and earthenware production.