Fly ash from coal fired power stations is a potential raw material for the production of ceramic tiles, bricks
and blocks. Previous work has demonstrated that the addition of metals can significantly alter fly ash
sintering. Metal finishing produces problematic waste filter cakes and sludges that are increasingly diffi-
cult to dispose of to landfill. The objective of this research was to investigate the effect of selected metal
finishing wastes on the properties of sintered fly ash. A 10 wt.% addition of dried metal finishing sludge
obtained from the phosphate bath at a tri-cationic phosphating operation significantly reduced the sintering
temperature for maximum density by approximately 75 ◦C. The addition of the phosphate bath sludge
also reduced leaching of As, to the extent that fly ash ceramics containing this waste would be classified
as inert. Potential industrial applications for these novel waste-derived ceramic materials are discussed