Effect of "singular blended clay" on microstructure and thermo-mechanical properties of vitreous sanitary porcelain

An attempt has been made to develop a ``Singular Blended Clay'' (SBC) having plastic properties and dry strength required for the production of vitreous sanitary porcelain and tableware. A predetermined mixture of a crude china clay, plastic ball clay and a plastic fire clay from Indian origin were crushed, blended together and impurities removed by wet processing including gravity settling, screening, deironing and filter pressing. The physico-chemical properties of feed raw materials have also been studied with emphasis on singular blended clay and its influence on thermo-mechanical properties and microstructure of vitreous sanitary porcelain compositions. Progressive substitution of singular blended p to 60 wt % leading to almost complete replacement of traditional crude clays resulted in an increase of flexural strength (similar to 32%) and a rse in thermal expansion (similar to 22.7%) due to decrease in residual quartz content in the compositions. The addition of SBC had although little effect on the mullite content of the fired bodies but decreased the vitrification temperature by 50 degrees C and also enhanced the vitrification range