Technologies for Recycling Shredder Residue 2007-01-0526
Recovering metals from obsolete automobiles, home appliances, and other metal-containing obsolete durables and other scrap involves shredding these objects and separating the reusable metals from the shredded material by using magnets, eddy current separators, and metal detectors. Over 12 million automobiles are shredded annually in the United States alone, and almost all of the 4.5 million metric tonnes (5 million short tons) of the shredder residue produced in the United States annually is disposed of in landfills. Over 13.6 million tonnes (15 million tons) of shredder residue is generated worldwide every year. The rise in disposal costs is further exacerbated in that the percentage of shredder residue that must be disposed of, in comparison with the percentage of marketable recovered metals, is increasing because of the increasing content of polymers in automobiles and in home appliances. Many organizations worldwide, including Argonne National Laboratory (in cooperation with the Vehicle Recycling Partnership and the American Plastics Council), are developing technology for recovering materials from shredder residue for recycling. This paper reviews some of these technologies. These include mechanical, thermal, chemical, and thermo-chemical methods for separating and recovering materials and resources from shredder residue. Some of these technologies are on the road to commercialization in Europe and Japan where, in comparison with the United States, disposal cost is much higher and regulations are more stringent. Materials and resources recovered by these technologies from shredder residue include metals, plastics, rubber, fuels, and energy.