Magnetic separation is a unit operation whereby ferrous metals are separated from other waste materials by utilizing their magnetic properties. Magnetic separation is used to recover ferrous materials from source-separated, commingled, and shredded MSW. Magnetic separation is used commonly to separate aluminum cans from tin cans in source-separated waste where the two types of metals are mixed. Ferrous materials are usually recovered either after shredding and before air classification or after shredding and air classification. In ferrous materials before shredding (this operation is known as scalping).
When commingled MSW is burned in combustors, magnetic separation is used to remove the ferrous materials from combustion residue. Magnetic recovery systems have also been used at landfill disposal sites. The specific location such as the reduction of wear and tear on processing and separation equipment, the degree of product purity to be achieved, and the required recovery efficiency.
