Data were collected on energy requirements to recycle prompt industrial and obsolete scrap for nine metal commodities: iron and steel, aluminum, copper, zinc, lead, stainless steel, titanium, tin, and nickel and nickel alloys. Major process routes for recycling were considered, starting from the first collection point through scrap preparation, transportation, smelting and/or refining to the molten metal, ingot, or other semifinished form approximately equivalent to a primary metal of a similar composition. Available data for 1976 were collected in the amounts of each metal commodity recycled by major scrap categories. In addition, energy requirements were estimated for separating municipal solid wastes into four major categories: refuse-derived fuel, magnetic aluminum, and glass cullet fractions. Finally, areas of research were identified to enhance recycling and/or increase the efficiency of energy use.