Technological behaviour of some Tunisian clays prepared by dry ceramic processing


Lower Cretaceous (AJO and AJR) and Oligocene clays (AS) from northern Tunisia were analysed to evaluate their possible use in the production of earthenware tiles by dry processing and fast double-firing. The Cretaceous clays are carbonate-rich (AJO = 20%, AJR = 12%) while the Oligocene ones are carbonate-free. This led to noticeable difference,, in firing behaviour (shrinkage, sintering rate and loss on ignition and consequently in functional properties (water absorption, mechanical strength. porosity). The AJO firing shrinkage is very small. which makes this clav suitable for rapid firing. The clays are illite-kaolinite-rich but the AS sample is mostly smeetitic (44%) and so is used (10 wt.% maximum) only to adjust the consistency of the powder during pressing. The average agglomerate size ranges from 100 to 350 mu m and the distribution is suitable for easy pressing of powders without any special need for further adjustments. Characterization of fired products confirms the high potential of these clays since all properties fall within the ceramic International Standards (ISO). For both technical and economic reasons dry processing is recommended for production of earthenware tiles, in particular for countries in sunnier climates, where solar energy call be exploited for clay drying.



subject category

Chemistry; Geology; Mineralogy


Jeridi, K; Hachani, M; Hajjaji, W; Moussi, B; Medhioub, M; Lopez-Galindo, A; Kooli, F; Zargouni, F; Labrincha, J; Jamoussi, F

our authors


This research received financial support from the Ministry of Higher Education, Scientific Research and Technology (Tunisia) according to the contract 'Programs with Foreign Research and Development Institutes in the Field of Materials Science' (Agencia Espanola de Cooperacion Internacional, Group RNM-0179 of the Junta de Andalucia). We wish to express our gratitude to three anonymous referees for their useful comments, and also to Prof. Ian Maccandless (Department of English and German Philology, University of Granada) for assisting us with the English version of the text.

Share this project:

Related Publications

We use cookies for marketing activities and to offer you a better experience. By clicking “Accept Cookies” you agree with our cookie policy. Read about how we use cookies by clicking "Privacy and Cookie Policy".