With the exception of some metals like uranium and plutonium, almost all metals can be recycled. Metals can be continuously recycled without undergoing any changes to their composition or physical characteristics. Metal recycling entails gathering scrap metal, crushing, compacting, removing non-metal components, and melting the metal in furnaces to produce metal sheets. The process of making new metals typically produces more greenhouse gases and uses more water and energy than recycling. Steel is one of the metals that is recycled the most, according to the AISI, out of all the metals.