In terms of production volume, aluminium is the leading metal in non-ferrous metallurgy. In particular, the recycling of aluminium-containing residues has increased strongly in recent years and will continue to gain importance in the future. Aluminium dross is a residue, which contains up to 80 % of metallic Al. It arises during the smelting, melt treatment and casting of aluminium and its alloys in primary smelters, foundries and recycling plants. On the one hand, the natural oxide layer leads to the formation of dross when remelting solid input materials such as aluminium scrap. On the other hand, it is also caused by turbulence and movements of the melt during furnace work.
In the present work, a literature study is conducted on the formation and possible further processing of aluminium dross. Within the scope of the experimental work, the remelting of different drosses originating from the production process is carried out with the addition of smelting salt on a laboratory scale. For this purpose, different drosses that are produced in the industrial process in a hearth furnace with the addition of different charge materials are used. By taking a sample of the dross that is as representative as possible, the evaluation of its metal content is carried out by remelting experiments with the addition of salt in the induction furnace. The quantities of dross produced in the production process are also evaluated. The results of these experiments are of considerable importance. On the one hand, they can be used to optimise the charging process with regard to the grading of the scrap and the timing of the addition of the different types of scrap. On the other hand, the metal yields achieved by external reworking of the dross are checked against the laboratory results.