Electronic printed circuit boards are complex assemblies that include numerous materials, and these materials require large quantities of energy and other materials to manufacture. They also include significant quantities of metals such as lead, copper and nickel. While some of these are toxic in nature, all of them are valuable resources.The recycling of electronic printed circuit boards begins with the circuit boards being passed through the Component Removal Machine. This machine automatically separates all the assembled components on the circuit board. It is then pulverized and shredded. The output from these processing stages is the blank board and its components. The blank board primarily contains copper, which is smelted and electro-refined to obtain 99.9% pure copper bars. The separated components are classified as heavy and light chips and include transistors, diodes, connectors and miscellaneous parts such as capacitors and heat sinks among others. Magnetic separation is carried out to separate ferrous metals as well as some of the copper alloys. This is followed by eddy current separation to separate non-ferrous metals. All of these components are smelted to obtain pure metals. Plastic components are separated through density based separation.