The Atlantic profiles Christmas light recyclers, a job that moved to China when the environmental restrictions in the U.S. became too onerous.
In the past the rubber was just burned off to get the metal, but now the rubber has become a valuable commodity in its own right. Recyclers had to develop a way to separate the rubber from the metal using techniques borrowed from miners.
As the table shakes, the heavier flecks of copper (from the wire) and brass (from the light bulb sockets) flow in one direction, and the lighter plastic and glass (from the insulation and bulbs) flows in another. It’s the same concept that miners use when panning for gold, and the results of this updated, age-old technology can be found at the far end of the water tables: baskets of roughly 95% pure copper and brass alongside baskets of insulation and glass.