Raw Kaolinitic Clays from Serbia and their Potential in the Production of Extruded Ceramic Tiles

Abstract

The present study analyses the usage possibility of the 7 raw kaolinitic clays from Serbia. The characterization of raw materials is done by using instrumental techniques to determine chemical and mineralogical compositions, particle size distribution and behavior during firing (changes in mass, temperature of the system and dimensions). Additionally, refractoriness is determined for each of the materials. The samples are shaped by the extrusion process and fired in a 1000-1250 °C range. The ceramic and technological characteristics of the fired samples are determined, and micromorphology is recorded. It is concluded that most of the tested clays can be used to produce cream-colored extruded ceramic tiles with water absorption between 0.20 and 5.28 % by firing at 1250 °C. The majority of the samples can be used as ceramic tiles for flooring purposes after firing at 1200 °C. Additionally, all samples are found suitable for special purpose roofing tiles production after firing at 1100 °C.