With the need for metal growing by the day and the supply being limited, recycling of metals is a major industry, also called the secondary metals industry. Therefore, recycling of scrap metals plays a key role in the supply chain of the metal industry and scrap metal discarded and sent to landfills is being recovered more and more by collectors. Household articles contribute in a big way to the supplies of the metal recycling industry and there are a number of small and large companies involved in recycling as well as in research and development of improved recycling techniques.