ABSTRACT
Recovery and recycling of waste metals acquire additional merit when consideration is given to the stress on technology and the increased environmental penalties of continually seeking recovery from more dilute concentrations from progressively more extensive areas. Several efforts have been made to assess the magnitude of the rates at which metal resources of the United States are being exhausted. An interesting comparison is the relative mineral self-sufficiency of two nations with large resources, such as the US and the USSR. An assessment by the US Office of Technology Assessment arrived at a hierarchy of technical options for conservation of eight metals: iron, copper, aluminum, magnesium, chromium, nickel, tungsten, and platinum. This hierarchy consists of substitution; product recycling; elimination of nonessential metal in products; extended product life; and reduced use of material-intensive systems such as alloys.
