Abstract

In the present work, coal fly ashes from a Spanish coal-fired power plant were used to synthesize zeolite using an alkaline treatment. The feasibility of making highly fire-insulated panels using these zeolitized fly ashes was examined. The panels were prepared using zeolitized fly ashes as the main component (50, 60, and 70% by weight) combined with gypsum, silica fume (4.5% by weight, constant), and glass fiber (9.5% by weight, constant). The manufactured panels had great water retention capacity and, consequently, showed up to 30% greater insulating properties compared to commercial gypsum panels. It was found that compression and bending strengths diminished as the proportion of zeolitized fly ashes increased, and the panels did not present any leachability of heavy metals or radiological problems. The panels developed with zeolitized fly ashes could potentially be useful as a component in construction materials for passive fire protection in doors and firewalls in buildings and industrial installations.