Experimental new recycling methods could save millions by blasting pure gold out of old SIM cards.
You might not realize, but every SIM card contains a little bit of gold. With millions of customers switching to SIM Only deals every year, there’s a lot of old, useless SIMs (and the gold inside them) that’s going straight into the bin.
A single SIM card only contains about 1 milligram of gold, but that tiny amount adds up quickly.
Over $22 billion of gold is wasted each year through discarded electrical products. This “e-waste” adds up to around 45 million tons globally, becoming one of the fastest growing sources of environmental waste.
Just 20% of e-waste ends up getting recycled, even though electrical products can contain numerous valuable materials, including silver, platinum and copper.
Current recycling techniques leave a lot to be desired. They are expensive, inefficient, and can’t simply can’t match the vast capacity of waste. What’s worse, is that these recycling processes can be damaging to the environment.
Recycling centers extract minerals from e-waste with powerful solvents and high-temperature furnaces. To get the gold of a SIM card, everything else must be melted and burned away.
This means that recycling plants have shockingly high carbon emissions, as well as dumping other toxic pollutants, like sulfur dioxide, into the atmosphere. It is recycling entirely for profit, and not to help the environment.
However, new research from Sandia National Laboratories has demonstrated a cheap, effective, and environmentally friendly method for extracting the gold out of SIM cards.
This new process involves coating SIM cards in a kind of detergent before submerging them in water. This lowers the surface tension between the water and the SIM card – creating tiny air bubbles when the water is blasted with ultrasonic waves.
These bubbles heat up rapidly, raising the temperature of the water to 4700°C. The combination of heat and pressure turns the SIM card’s water-bath into a tiny smelter, forcing the gold out in tiny “microjets” of particles.
The gold particles can then be collected out of the mixture and easily recycled into a usable state.
Using sound waves to heat gold instead of typical methods results in far lower energy consumption, and very little environmental damage from emissions.
The technology, called “cavitation”, is still within its experimental stages, but researchers hope to expand the technology to extract further valuable metals, such as palladium, from other types of electronic waste in the future.