After being de-coated, the aluminium shreds are fed into melting furnaces containing submerged stirrers that create a vortex in the pool of molten aluminium and drag the shreds quickly down into the melt. The molten metal is transferred into a holding furnace, where it is treated to remove impurities before casting the aluminium. Ingots are cast by tilting the holding furnace and pouring the molten metal into a casting unit. The metal is treated in a two-stage process to remove any remaining microscopic, non-metallic particles and gases, with chemical composition and metal cleanliness tested on each cast. As the metal flows into the moulds, it is chilled by jets of cool water pumped around and through the base of the mould. The aluminium ingot solidifies gradually during the casting process, which takes approximately three hours. This is then re-used as cans throughout the UK, and abroad.
Steel cans, tins and aerosols