Effect of moisture content on extrusion process of kaolinitic–illitic clay in manufacturing of ceramic Raschig ring

The investigation addresses the effect of moisture content of typical illitic–kaolinitic clay on behavior of extruded ceramic Raschig ring. Extrusion behavior was assessed by determining bulk density and total porosity of green body. The shaped bodies were sintered at 1200 °C and diametric shrinkage, water absorption, bulk density, porosity, as well as diametric compressive strength were measured. The strength data were analyzed statistically by Weibull theory. It was found that with rising of moisture content in paste the reliability of compressive strength decreases considerably. The finding results were confirmed on studying the sintered samples with a scanning electron microscopy.