This article was taken from the March 2014 issue of Wired magazine. Be the first to read Wired’s articles in print before they’re posted online, and get your hands on loads of additional content by
There’s gold in them thar circuit boards — laptops, phones, cameras and other devices use the precious metal to connect components, and it can be extracted relatively simply. A typical handset holds around 0.2g of gold, which means about £1.80 for your pocket.
lectronics-technology engineer Josehf Lloyd Murchison claims he has extracted up to $1,600 (£980) worth of gold in three months of collecting junk electronics — and you can too. “Surprisingly, chemical recovery of gold takes almost no skill,” he says.
However, you should only attempt this if you have a basic knowledge of chemistry and are aware of the dangers of working with the chemicals and tools mentioned on the right. Make sure you have suitable protective equipment (goggles, gloves and overalls to protect your clothes) and a suitable and well ventilated (or outdoor) work space. Some of the chemicals produce noxious fumes, are highly flammable or strong oxidants, and can cause skin burns. Learn basic first aid before you try this.
“Hydrogen peroxide is used to bleach hair and is a good antiseptic,” says John Turner, a reader in inorganic physical chemistry at the University of Sussex, “and although hydrochloric acid isn’t usually found in the house, the actions are very easy to do. It’s the possible hazards [from the chemicals] that gives you the frisson. If you are careful, I don’t really see [the experiment] as a problem. Someone with A-level chemistry should be able to do it.”
Collect your scrapsIn phones, most of the gold is in the SIM card, the main board and the smaller components on the back of the LCD screen. Use a magnet to separate all gold-plated steel parts, as you need a different process to extract it. “Older electronics have more gold in them,” says Murchison. “The best thing I extracted gold from was industrial video equipment — a couple of ounces [up to 56g] per machine.”
Strip out the boardsPlace your circuit boards in a glass vessel. In another container, mix two parts hydrochloric acid and one part weak hydrogen peroxide (a concentration of three per cent).
Pour this mixture over the circuit boards so they are completely submerged. Wait for a week, giving the vessel a stir every day with a glass or plastic rod. Over time, the acid will darken and gold flakes will come off the scraps.
Collect the flakesPour the mixture through a coffee filter and into another glass container. The gold flakes will be left behind. Pour the remaining circuit-board bits into a deep plastic tray filled with water. Save any pieces with remaining gold for re-dipping. Pour the water through the filter to collect any gold dust, and flush the flakes with water. Wash them with methanol, then again with water to rinse away any residue.
Melt the goldWearing protective, flame-resistant clothing, boots and goggles, heat a clay bowl with a blowtorch. Add some borax (available from chemists); this enables the gold to be melted at a temperature lower than 1,064C. When the borax begins to soften, add the gold flakes. Heat until the flakes melt into a gold bead. Now let it cool before chipping the gold out of the re-solidified borax