Pore structure of lightweight clay aggregate incorporate with non-metallic products coming from aluminium scrap recycling industry

This paper deals with the non-waste utilisation of aluminium recycling waste called non-metallic products (NMP) and their reprocessing into environmentally friendly material. In the present studies, lightweight expanded clay aggregates were produced from natural plastic clay and NMP. They were obtained recovering Al metal from black dross by using conventional metallurgical process. Based on the results obtained from chemical and mineralogical investigations of NMP, heat treatment in the temperature range from 1150 °C to 1280 °C was selected as an appropriate method to eliminate impurities of residues, such as aluminium nitride (AlN), iron sulphite (FeSO3), aluminium chloride (AlCl3). Emissions of gases during high-temperature treatment of NMP act as initiators to create extra porous structure of sintered ceramic bodies. The effect of raw material composition, previous treatment of NMP and sintering temperatures on the aggregate's properties were evaluated. Physical and microstructural properties of sintered aggregates were determined.