文摘
The present work aims at the characterization and leachability examination of aluminium dusts, generated during the secondary aluminium production from scrap. Two different types of dusts were examined: a cyclone aluminium dust and a fabric filter aluminium dust, derived from the waste gases de-dusting system, produced during the Al scrap meltdown. The characterization of both dusts was carried out using particle size distribution analysis, chemical analysis, X-ray diffraction and thermogravimetric/differential thermal analyses. Their microstructure and morphological characteristics were examined by scanning electron microscopy and transmission electron microscopy. The results showed that the basis of the examined dusts was different, as they consisted of different mixtures of metallic aluminium, salt flux constituents, aluminium oxide and aluminium nitrides. Their behaviour during leaching was determined by the toxicity characteristic leaching procedure test and the EN 12457-2 compliance leaching test. The results revealed that both dusts should be treated as hazardous wastes and in case of landfilling they should be disposed of at appropriate, regulation-prescribed waste dumps, after removing the water-soluble phases, such as chlorides or nitrides.KeywordsSecondary aluminium dustCyclonesFabric filtersCharacterizationLeachability