
6 Aluminum Recycling
Aluminum recycling was at rst conducted directly, with purchased scrap being
consumed by foundries without prior treatment (Aluminum Association, 1998).
However, as scrap began to travel over greater distances and the reliability of its
composition improved, it became desirable to produce a scrap product of greater
consistency. As a result, secondary smelters began to appear after 1910 (Hollowell,
1939). These smelters produce a secondary ingot from mixed loads of scrap, with a
composition matching one of several standardized grades. Table 1.1 lists the com-
positions of secondary alloys specied in the United Kingdom in ...