APPLYING OF ALUMINIUM SCRAP RECYCLING WASTE (NON-METAL PRODUCT, NMP) FOR PRODUCTION ENVIRONMENTAL FRIENDLY BUILDING MATERIALS

An aluminium scrap recycling waste called non-metal product (NMP) was tested as raw material for production of expanded clay aggregates. Processing of NMP created in the aluminium scrap recycling companies is one of the most challenging tasks due to its toxic nature in accordance with the Basel Convention, Annex III, marking of this waste is H 4.3 (reaction with water results in highly inflammable substances) and H 10 (reaction with water results in increased concentration of toxic gases, for instance, ammonia). The main phases of the starting waste are spinel (FeAl2O4) or (MgAl2O4) and aluminium nitride (A1N). The main task of the present research is to investigate the possibility of non-waste utilization of NMP and reprocessing it into environmental friendly material. The heat treatment in the temperature higher than 1100 degrees C was selected as appropriated method in order to eliminate impurities of NMP, like ammonia and others. It is approved by results obtained from chemical and mineralogical investigations of expanded clay aggregates. The phenomenon of gasses emission during the heat treatment of NMP is used as initiator for creation of extra porous structure of sintered ceramic bodies. Physical, mechanical and microstructural properties of sintered aggregates were determined as well as chemical and mineralogical composition of raw materials and end product were fixed.