Creation date
Metal: any of a class of substances characterized by high electrical and thermal conductivity as well as by malleability, ductility, and high reflectivity of light. Approximately three-quarters of all known chemical elements are metals.
The most abundant varieties in the Earth’s crust are aluminium, iron, calcium, sodium, potassium, and magnesium. The vast majority of metals are found in ores (mineral-bearing substances), but a few such as copper, gold, platinum, and silver frequently occur in the free state because they do not readily react with other elements.
Shredding process: Providing the economic recycling solution for ELVs
The vehicle-recycling plants processes vehicles into high-density fist-size pieces by using powerful shredding. The separated, shredded ferrous scrap that is produced is ideal for direct feed use in the furnaces of steel manufacturers. This material is of high physical and chemical quality, (ferrous content of 98%), and is highly sought after by steel manufacturers worldwide.
Shredders originated in the late 1950s to deal with the increasing number of ELVs. Prior to the invention of the shredder, the ELVs were manually dismantled – this process eventually became too slow to keep up with even the relatively low volume of ELVs in those days. Shredders have been steadily improved to increase efficiency, enhance the purity of the end-products. Much of the focus of these improvements has been on optimizing the separation of the metals. Many vehicle components are made of non-ferrous metals such as copper, aluminium and zinc. In the shredding process, magnetic separation is used to remove the magnetic ferrous fraction from the other materials. The non-ferrous metals are then processed further to segregate the various types. Foucault, eddy-current, separators induce energy that will literally magnetically separate one non-ferrous metal from another and any surrounding materials. Other various technologies are also used for separating shredded materials as needed.
Producing high quality products
Media separation plants employ fluids or mineral suspensions of varying specific gravity that allow selected materials to float while others sink. Therefore, a succession of various media separation stages, within a single plant, can effectively separate all non-ferrous metals. Media separation plants currently recover around 99.5% of the non-ferrous metals from shredded vehicles. Ongoing improvements continue in order to capture the other half percent.
The best environmental & effective solution
Not all separated materials are of reuse; and some residues are leftover. There are two main types of residues: the airborne dust ('fluff') caught by the shredder dust collection system, (consisting of upholstery fibres, dirt, rust, paint, etc.); and the non-metallic residues separated from the recovered materials by the media separation plants (consisting of unusable rubbers, plastics, stones, etc.). The airborne dust and the separated residues together represent about 17-25% of the average vehicle weight. However, progress in media separation technology is continuing and now enables some materials to be further recovered, while the remaining combustible materials may have potential as a fuel. Research and development continue in this area.
The EU's shredder and media separation infrastructure are economically self-supporting and positive for the environment. In addition to vehicles, millions of other consumer durables, including washing machines and other household appliances, are also processed – avoiding ending up in landfills. These plants provide first-grade processed materials to consumers worldwide, generating revenue for exporting countries; and because secondary materials are naturally less expensive than primary materials this offers a cost advantage to the industries that consume them. The use of secondary raw materials is highly beneficial, providing appreciable energy savings and producing fewer emissions.
Source: www.bir.org & https://www.bir.org/the-industry/ferrous-metals