Posted: May 14, 2014
Source: U.S. Energy Information Administration
The production of iron, steel, and aluminum is a highly energy-intensive process, accounting for 10% of total manufacturing energy use. The use of recycling in the manufacturing process of these metals has been a main driver of improvements in energy efficiency within the industry.
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% less energy than the production of steel from iron ore, while the U.S. Department of Energy reports that secondary aluminum production requires 90% less energy than primary production.
Secondary production accounts for nearly 60% of U.S. aluminum production (counting both old and new scrap), while primary production accounts for almost 40%. Similarly, recycling is used in most steel production. According to the U.S. Geological Survey (USGS), 40% of U.S. steel production in 2011 came from basic oxygen furnaces (BOF), whose inputs are almost 80% pig iron (molten iron), whereas 60% of production came from electric arc furnaces (EAF), which use more than 90% scrap.