Scrap can be recovered from structures, industrial machines and equipment, and consumer goods. Some structural materials (construction steels, bridges, rails, etc.) can recovered easily to provide consistent scrap qualities.
End of life vehicle scrap
One major source of steel scrap is from end-of-life vehicles. In 2010 the global fleet of vehicles exceeded 1 billion and is projected to reach 2.5 billion by 2050. New vehicle production will exceed 60 million for the first time. Assuming that each vehicle produces about one tonne of steel scrap, this gives an indication of the size of this market.
The current method for processing vehicles is predominantly partial dismantling and shredding. Vehicle designers have not always taken end-of-life management into account. For example, the use of mercury tilt switches for alarm systems in the past resulted in increased levels in mercury in EAF dust. Moreover the increased use of small electric motors in vehicles (for windows, mirrors, seats, etc) has made it more difficult to produce scrap with low copper contents.
Smaller items and consumer goods are often collected as part of mixed waste streams and must be processed to recover the steel content. This material will often be galvanised, and/or coated with paints systems or plastics. The inclusion of significant volumes of galvanised steel scrap in steel melts will result in elevated levels of zinc in the dust collected in the furnace off-gas system.