There are two principal methods in use for processing the 8 million cars that are scrapped annually in the United States. About one-half of the cars are processed by shredding in which automobiles minus radiators, batteries, engines, gas tanks, and seats are ripped into fist-sized chunks and then magnetically separated to produce a ferrous scrap fraction and a nonmagnetic fraction. The remaining half of the cars are processed by hand removal of nonferrous, steel, and cast iron parts from the burned or unburned cars, followed by baling or shearing of the stripped hulks. For both methods, the starter and generator (or alternator) are generally removed, although the number of generators still exceeds alternators on scrapped cars, this ratio will shift markedly in a few years because, by 1968, alternators became standard equipment on almost all cars. Currently, the starters, generators, and alternators scrapped annually are estimated to contain 20,000 tons of copper and 130,000 tons of iron. Improved techniques for incineration and dismantling have been reported and are gradually being adopted by scrap processors.
