Novel Ceramic Pigments Based on Industrial Wastes

Abstract

We report the preparation of ceramic pigments using industrial wa stes as primary sources. An Al-rich sludge (generated in the wastewater treatment unit of an anodising or surface coating industrial plant), a galvanizing sludge (from the Cr/Ni plating process ), a Fe-rich sludge (generated during steel wiredrawing), a foundry sand and a marble sawing sludge are combined to formulate distinct pigment structures via the solid state reaction method. In particular, a black spinel and a novel blue pigment based on the hibonite structure are detailed. A green olivine, and brown and pink sphenes are also reported. The pigments were fully characterized, and then were tested in a standard transparent bright ceramic glaze. Typical working conditions and colour development are fully described.