Influence of sintering temperature on raw and beneficiated clay “Klokoti”

The raw clay ?Klokoti? from middle Bosnia was beneficiated by method of wet separation which results in removing fraction over 20 ?m. The raw clay was characterized by chemical composition, grain size distribution and characteristic temperatures on heating microscope. The beneficiated clay was characterized by chemical composition and characteristic temperatures. The phase composition of raw and beneficiated clay was observed by RDA while the microstructure was monitored on scanning electron microscope (SEM). The sintering process was performed at 1100?C, 1250?C, 1320?C and 1400?C with two hours holding time at the highest temperature. The obtained results indicate a big content of coarse quartz in raw clay and gradually increase of crystalline mullite content with increasing temperature of sintering. Beneficiated clay at higher temperature of sintering produces larger glassy phase content, which is result of larger fluxing content in its composition. It is also observed that from beneficiated clay by sintering at 1250?C crystallize the most mullite along with minimum porosity and the lowest glassy phase content.