The recycling of metals—II. Nonferrous metals

Abstract

This paper deals primarily with the recycling of copper, aluminium, lead and zinc and also with some aspects of that of other nonferrous metals. Nonferrous metal recycling is highly developed. Home scrap, prompt industrial scrap and old scrap are recovered. Old scrap is most important for metals such as copper which have been in use for a long time. Nonferrous scrap is beginning to be recovered by auto shredders. The recovery of nonferrous metals from municipal solid waste will mainly involve aluminium. The nonferrous secondary industry collects, sorts and physically processes scrap. Some scrap, in particular copper and lead, is metallurgically processed either in primary or secondary circuits; others, such as aluminium, are usually recovered in separate secondary circuits. The purity of the scrap determines the extent of processing carried out. Alloys are largely recovered as alloys. The secondary metals produced may be of the same quality as primary metals but some are of lower quality and are used in appropriate applications. Prompt industrial and old scrap make appreciable contributions to supplies; they are ca. 50% of current consumption for copper and lead and ca. 20% for aluminium. Secondary production of nonferrrous metals is less capital-intensive, consumes less energy and tends to be less polluting than primary production.