We are talking about computers that had already served their time. In landfills they accumulate so much that in Germany recently built a factory for processing "computer recycling". The fact that this waste a lot of precious metals, which still can be used. First old computers pressed into blocks, which are then crushed into a fine powder. The magnets extract the iron, and the remaining mixture of polymers and non-ferrous metals into the plant, where compressed air "blow away" plastic dust. Then, using chemical methods of metal powder is divided into copper, silver and other metals, including gold.