Steel is the most recycled material on the planet, more than all other materials combined. Steel retains an extremely high overall recycling rate, which in 2012, stood at 88 percent.
The amazing metallurgical properties of steel allow it to be recycled continually with no degradation in performance, and from one product to another.
The sources for steel scrap are plentiful, but are classified into three main categories: home scrap, prompt scrap and obsolete scrap.
Home scrap is the scrap that is produced from within the mill itself and is available within weeks. Prompt scrap is scrap that it is produced from manufacturing products from steel, and is available within months. Obsolete scrap is scrap produced from steel products at the end of their lives and it may be decades before this scrap is available (example: The Golden Gate Bridge).
Even while two out of every three tons of new steel are produced from old steel, it is still necessary to continue to use some quantities of virgin materials. This is true because many steel products remain in service as durable goods for decades at a time and demand for steel around the world continues to grow.
Beyond the steel scrap itself, the steel industry has long recycled its by-products: mill scale, steelmaking slags, water and processing liquids. Likewise, steelmaking dusts and sludges are processed so that other metals, such as zinc, can be recovered and resused.