An excellent conductor of electricity that does not oxidize, gold is an important component of modern technology. Few people know, but all our smartphones and computers contain small amounts of this precious metal. Of course, you can’t get rich by dismantling just one of your phones, but if someone did it on an industrial scale, they could make a lot of money from it.

How does it work

Researchers have developed a new method to extract gold from electronic waste. This method is based on a by-product of the food industry and is therefore cheap and therefore profitable: According to the team, you can get $50 worth of gold for every dollar you spend.

Also, according to them, this an incredibly environmentally friendly process. The team behind the method discovered that protein fibrillar sponges, made from protein-rich by-products of cheese making, could be used to extract gold from discarded e-waste.

As detailed in a new paper published in the journal Advanced Materials, the team Managed to extract 450 milligrams of 22-carat gold nugget from just 20 old computer motherboards. To do this, the team denatured whey proteins under acidic conditions and at high temperatures, creating a suspension of protein nanofibrils. They then dried this gel and created a sponge.

After melting and ionizing the metal parts of 20 motherboards in a bath, they placed a sponge in the solution to attract gold ions. By heating the sponge, the team turned the collected ions into flakes and eventually melted them into a small gold nugget. This 450-milligram bar was 91 percent gold and 9 percent copper. At the current exchange rate, that’s about $33.

According to the team, energy costs are only 50 percent of the value of gold that can be mined, making this process incredibly profitable at scale. The researchers are now looking to bring their idea and other protein-rich byproducts that could be turned into sponges to market.