The use of recycling in the manufacturing processes of materials such as iron, steel and aluminium has been “a main driver” of improvements in energy efficiency within the industry.

That’s according to the US Energy Information Administration (EIA), which suggests production of these metals accounts for 10% of total manufacturing energy use.

“Primary production, in which steel is made from iron ore and aluminium from bauxite ore, is energy intensive. However, secondary production, which involves the use of recycling scrap to make steel and aluminium, is much more energy efficient”, the EIA said.

Estimates from the Environment Protection Agency show secondary steel production uses around 74% less energy than the production of steel from iron ore while the US Department of Energy reported that secondary aluminium production requires 90% less energy than primary production, it added.

The US exported 24.3 million metric tonnes of scrap in 2011, the EIA said.