How are old automobiles processed to recover steel and other reusable materials?

The processing of end-of-life automobiles is a systematic operation designed to recover valuable materials and minimize waste. The process typically follows these stages:

• Salvage: Before reaching a reprocessor, vehicles are stripped of functional parts, such as transmissions and electrical components, which are rebuilt and resold. Engine blocks are often removed to be melted down for recasting.1
• Preparation and Shredding: The remaining automobile body is crushed and flattened. It is then fed into hammer mills, which shred the metal into small pieces.1
• Material Separation: Powerful magnets are used to extract ferrous metals (iron and steel) from the shredder residue. Other materials are separated using manual sorting or jets of air.1
• Recovery: The recovered scrap steel serves as a vital feed for electric arc and basic oxygen furnaces. While plastics, textiles, and rubber from the residue are generally not reused, manufacturers are increasingly designing vehicles with end-of-life recycling in mind to improve material recovery rates.12

This process is essential for the secondary aluminum industry as well, as discarded automobiles provide a significant source of "old" scrap metal.3