Metal Sensing, Metal Separation, and Metal Sorting
Metallic compounds are in a finite supply on Earth. The demand for these materials is approaching infinite. In order for the supply of metals to meet the demand, recycling of used materials is a necessity in the modern world. Many foundries are now equipped to handle and refine the materials from metal recycling centers. Before new products can be made from the old metals, first the recycling center must detect the metals in recycled materials, remove them from other components, and sort between the different types of metal.
Metal sensing is the first step a recycler must take. Bulk recyclers take in shredded cars, extra materials from construction, and waste from demolition sites. From this, they have to detect the different types of metal in a massive mixture of plastics, glass, rubber, and other components. Magnets can be used to remove any steel, iron or other ferrous metals. However, this won’t work on aluminum and other nonferrous metals. Other metal sensing techniques must be used for these other metals. The techniques may include x-ray detection, vacuum technology, and by creating magnetic eddy currents to electrically charge the metallic items.
Metal detecting and metal separation from other recyclable materials are complimentary parts of the recycling process. Removing the metals from other recyclable materials also separates some of the different types of metals from each other. For further recycling, more metal separation must be completed. Some of this is done by hand by smaller recycling centers. Others will melt down the composite metals and separate them in their liquid forms.
Metal sorting is only the beginning. The resulting metal scraps must then be processed in order to be reused. The exact process is determined by the metal, how it was previously used, and and what it will be used for next. As general rule, processing plants will pay a higher price for metals of higher quality and purity. Removing impurities from scrap after the metal sorting process usually involves melting the metal down and refining it in a manner similar to removing the metal from its ore. This results in metals close to pure and ready for manufacturing into something new.