When the term “venerable goldmine” is used, it’s hard to conjure up images of old computers, used cell phones and broken keyboards. But old devices contain a surprising amount of useful and valuable metals that would be a shame to let go to waste. So just what types of metals are lurking in that outdated computer or old cell phone? 
Last year, London artists Revital Cohen and Tuur Van Balen decided to delve into old electronics to show us just what precious metals were contained therein. They grabbed a bunch of old computers and machinery from a bankrupt factory and decided to pull out the precious metals. What they have to show us is a hunk of precious metals that looks like it was pulled straight from the ground. It puts into perspective the raw materials that could still be used in other devices. The chunk of rock contains gold, copper, tantalum, aluminum and whetstone, all kept separated enough to really see what goes into our devices. That’s just from factory computers and equipment. 
The EPA gives some numbers on the staggering amount of precious metals we have in our electronics: “One metric ton of circuit boards can contain 40 to 800 times the amount of gold and 30 to 40 times the amount of copper mined from one metric ton of ore in the US.” The EPA also lists that cell phones alone contain gold, silver, platinum, palladium, copper, tin and zinc. Those recovered materials can then be used in plating, jewelry, electronics, cars and art. 
To put some more numbers on it, the EPA states that for every 1 million cell phones recycled we can get these amounts of precious metals: 
  • 35,274 pounds of copper 
  • 772 pounds of silver 
  • 75 pounds of gold 
  • 33 pounds of palladium 
An old computer alone contains a host of metals waiting to be harvested. The Refining Company, Inc. gives a good breakdown of an old computer, complete with photos by part. Gold a key part of most circuit boards, due to how great of an electricity conductor it is, its malleability and its resistance to tarnish. The power supply has an iron core inside. Silver and palladium make up the solder and components of many circuit boards. Although less precious of a metal, steel makes up part of the outer casing. Gold-plated pins and connectors run throughout the machine, as well. Copper makes up the connective wires. 
A study out of the Harare Institute of Technology also listed that printed circuit boards contain, “about 20 wt% copper, 0.04 wt% gold, 0.15 wt% silver, and 0.01 wt% palladium,” with wt% representing percentage by weight. A chart in the study from the Proceedings of the International Conference on Sustainable Solid Waste Management also listed the presence of precious metals in keyboards, personal computers, printed circuit boards and car electronics. Silver, gold, copper, zinc, nickel, bismuth, iron and antimony are present in all four devices listed. Silver, gold, copper, zinc, iron and antimony have a recycling efficient percentage in the 60 to 99 percent range. 
Vague statements always get tossed around about how there are “a lot” of precious metals in our electronic devices, but here are the hard numbers and lists that tell us just how valuable our old electronics are.