Abstract:
Red clay is one of the cheapest types of clay commonly found in Sri Lanka. The potsherds
and roof tile pieces unearthed all over the island, bear witness to the use of clay for
various purposes in the past. The present study explores the possibility of using the
fillers and fluxes treated with red clay for the preparation of cookware and tiles. Eight
samples of the traditional earthenware were prepared with different compositions. The
first three samples were prepared using 15 wt%, 20 wt% and 25 wt% of red clay. Among
the prepared three samples, 15 wt% red clay sample found to be best for further studies
for improvement of physical properties. The optimized sample was treated with fillers
and fluxes of fumed silica, alumina, talc, rice husk ash, and calcite to investigate their
physical properties such as density, viscosity, thickness, particle size, drying or firing
shrinkage, firing color, loss on ignition, water absorption, and modulus of rupture. It was
found that all fillers and fluxes could be used to improve certain important properties
of red clay. The optimum firing temperature for all the samples was 800 oC. Results
of this study show that all the physical properties of earthenware and tiles have been
enhanced comparable with other similar high-quality materials. Findings of this study
hence useful for production of quality cookware and tiles for domestic and exportation
purposes.
