The production of iron, steel and aluminum accounts for 10 percent of total manufacturing energy use, according to the US Energy Information Administration. However, metal recycling is saving significant amounts of energy.
Primary production, in which steel is made from iron ore and aluminum from bauxite ore, is energy intensive. However, secondary production, which involves the use of recycling scrap to make steel and aluminum, is much more energy efficient. The Environmental Protection Agency estimates that secondary steel production uses about 74 percent less energy than the production of steel from iron ore, while the US Department of Energy reports that secondary aluminum production requires 90 percent less energy than primary production.
Secondary production accounts for nearly 60 percent of US aluminum production (counting both old and new scrap), while primary production accounts for almost 40 percent. Similarly, recycling is used in most steel production. According to the US Geological Survey, 40 percent of US steel production in 2011 came from basic oxygen furnaces, whose inputs are almost 80 percent pig iron (molten iron), whereas 60 percent of production came from electric arc furnaces (EAF), which use more than 90 percent scrap.