Physicochemical and ceramic properties of clays from jebel kebar (Central Tunisia)

Resumo

The mineralogical and chemical compositions and the physical properties are determined for three representative clay samples from the Sidi Bouzid area in Tunisia in order to evaluate their industrial aptitude for ceramic applications. The semi-quantitative mineralogical analysis shows that illite and kaolinite are the major clay phases associated with crystalline phases as quartz, K-feldspar and calcite. In addition, some quantities of smectite, interstratified illite–smectite, dolomite and gypsum are also detected. The chemical analysis reveals that the silica phase is relatively high. The CaO rate is approved by the mineralogical analysis. The classification of the selected clays by the Holtz and Kovacs diagram suggests their possible use in the manufacturing of the red bricks in ceramic industry. For the Geotechnical test, ceramic products were prepared by mixing the three clays with different weight proportions (40, 40, and 20% respectively for green clay, red clay and red silty clay samples).