Microstructure and Phase Analysis of Ethyl Silicate-Bonded Alumina-Zircon Refractories

Abstract

Alumina-zircon refractories are prepared using an aqueous ethyl silicate solution as the gel-polymerized bond. Test specimens are heat-treated by reaction sintering at different temperature (1450 – 1600°C) and holding times (1 – 4 h) to yield new refractory phases zirconium dioxide and mullite. The specimens are tested for strength, porosity, sintering shrinkage, apparent density, and chemical and phase composition using x-ray diffractometry and electron scanning microscopy. Reactive sintering is shown to be a effective route towards obtaining ethyl-silicate-bonded alumina-zircon refractories with tailored microscopic and physical properties.