Representative Sampling, Fractionation and Melting of Al-Scrap

Abstract

The production of deoxidation granules for steel metallurgy is done by the re-melting of aluminium scrap in a two-chamber furnace. In order to determine the amounts of aluminium, non-metals and foreign metals in mixed scrap of an Austrian Al-smelter, representative sampling of Al-scrap is first carried out. Subsequently, the obtained sample is divided manually into the different fractions. These are, on the one hand, the fractions of aluminium and foreign metals like Cu, Fe, Zn and brass, and on the other hand, non-metals such as plastics, glass, wood and fines. Accurate characterization of the separated fines is done by TGA, TC, XRF and XRD analysis. Furthermore, melting experiments of the scrap on laboratory scale into a primary aluminium melt are conducted according to the industrial process. The results are of great importance, since the quality of the scrap influences the melting process significantly and the purchasing department must adjust accordingly.