Some barriers to the use of materials recovered from municipal solid waste
Abstract Municipal solid waste (MSW) contains materials which could be put to good use, yet it continues to be discarded, which suggests that it contains little or nothing of value under current conditions. This paper discusses the technical reasons for the lack of commercial interest in recovering materials from MSW. After examining the nature of the salvage industry and trends in the use of materials, the paper considers the characteristics of secondary materials, the properties required of them, and the scope for increased salvage activity. The market prospects are described for waste paper, ferrous and non- ferrous scrap, glass and polymers.
The influence of tin content on the reuse of magnetic metals recovered from municipal solid waste
Abstract The magnetically recoverable fraction of municipal solid waste (MSW magnetics) contains a large percentage of tinplate steel cans and, therefore, significant tin content. For areas where detinning is not readily available, this tin content is recognized as a potential barrier to the use of MSW magnetics in iron and steel production. Published reports on the effects of tin in iron and steel are reviewed. Tin is usually reported to harden steel, increase yield and tensile strength and decrease ductility and toughness, but the quantitative effects of tin have not been well defined. Reported tin levels in MSW magnetics are presented and a geometrical progression model for calculating tin residual buildup after repeated recycling is described. Based on tolerances for tin, a hierarchy of potential uses for MSW magnetics is proposed On a national scale, tin, by itself, would not present a barrier to reuse of recovered magnetics but this is not necessarily so on a local scale. Some steel plants, because of the types of products made, may not be able to reuse any MSW magnetics. Technological approaches to removing tin or reducing its effects are discussed.
The automobile as a renewable resource
Abstract The present system which has led to a high rate of recovery of the ferrous and non-ferrous metals from the obsolete automobile processed by shredding is described. Projections of the potential resource recovery from the non-metallic components of the shredded automobile are presented along with a detailed account of the current research and development programme directed toward such recovery.