The de-coating is a thermal treatment applied on the aluminium scrap, used to remove from the surface of the material all the contaminants as paper, oil, links, paint, plastic.

Drosses are generally classified in accordance with metal content into white and black dross. White dross contains larger quantity of aluminium content and it is produced from primary and secondary aluminium smelters. White dross contains from 15 to 70% recoverable metallic aluminium and it contains a fine powder from skimming the molten aluminium. For the case of black dross, it contains lesser metal content and is generated during aluminium recycling. Black dross consists of a mixture of aluminium oxides and slag, with recoverable aluminium content ranging between 12 and 18%, and larger salt content i.e., higher than 40% compared to white dross. The term ‘salt cake’ signifies the non metallic residue obtained from dross smelting operations and generally contains 3–5% residual metallic aluminium. It was reported in the literature that about four million tonnes of white dross and more than one million tonne of black dross is being produced every year and about 95% of this is landfilled.

As for our company we use machines for decoating of waste aluminums, and then recycling to other areas.