Your outdated tech might be a ‘goldmine'

Yahoo

28-06-2025

In 2025, it's not uncommon for a typical household to have a drawer overflowing with discarded phones and cables. But this graveyard of circuitry isn't just a static memorial to past tech trends. For those willing to put in the effort, each of those old iPhones and micro USB cables still contains a small amount of valuable metals and minerals—including gold. Researchers estimate that a single printed circuit board can contain around 200–900 mg of gold per kilogram.
The actual extraction of those precious metals from discarded tech is a labor-intensive process. Historically, it has often required the use of highly toxic chemicals like cyanide and mercury, which can be harmful both to the individuals doing the extraction and to the environment. But, researchers at Flinders University in Australia now say they've developed a new method of gold extraction and recycling that is far less hazardous and may have a lower environmental impact if scaled for production. By using a leaching reagent derived from trichloroisocyanuric acid—a sustainable compound commonly used in water disinfection—they were able to dissolve and extract gold without relying on dangerous chemicals.
The researchers, who published their findings in the journal Nature Sustainability this week, demonstrate they could use their process to extract gold from e-waste, as well as used ore.
'Overall, this work provides a viable approach to achieve greener gold production from both primary and secondary resources, improving the sustainability of the gold supply,' they write in the paper.
Gold has captured human attention for millennia. It backed the currency of empires, adorned countless pieces of royal jewelry, and has come to the rescue in root canals. Today, the coveted element is widely used in electronics, valued for its natural electrical conductivity, durability, and high resistance to corrosion. As a result, small amounts of gold are likely present in most of the devices found on a typical office worker's desk. And while tech companies have taken steps to extract and recycle that gold for years, much of it still ends up in landfills. The United Nations estimates that the world produced around 62 million tons of e-waste in 2022—a figure that's up 82 percent from 2010.
Contamination from toxic substances used to strip gold from devices isn't the only concern. The industrial leaching process typically requires vast quantities of water, further compounding its environmental impact. Runoff from those facilities can also make their way into food supplies or local wildlife.
The Flinders University researchers took a different approach. First, they developed a process using the trichloroisocyanuric acid that, when activated by salt water, effectively dissolved gold without the need for toxic substances. Next, they bound the dissolved gold to a new sulfur-rich polymer they designed themselves. The polymer was engineered to serve as a vehicle for selectively capturing gold, even in the presence of many other metals. Once the gold was extracted, the polymer could 'unmake' itself, reverting to its monomer state and leaving the gold behind. That fully separated gold could then be recycled and used again in new products.
'The aim is to provide effective gold recovery methods that support the many uses of gold, while lessening the impact on the environment and human health,' Flinders University professor and paper authorJustin Chalker said in a statement.
In testing, the researchers demonstrated that their process could extract gold not only from e-waste, but also from ore concentrates and scientific waste streams. Although, the sheer volume of global e-waste makes it the most obvious candidate to benefit from this method. The researchers say they are currently working with mining and e-waste recycling companies to test the process on a larger scale.
'We dived into a mound of e-waste and climbed out with a block of gold!' Flinders University research associate and paper co-author Harshal Patel said in a statement. 'I hope this research inspires impactful solutions to pressing global challenges.'
That said, everyday electronics consumers don't need to wait for this new method to scale up in order to benefit from e-waste recycling. Most major cities have certified e-waste recycling centers that accept large quantities of discarded electronics. Local scrap yards, as well as some private companies, will also pay a small amount for scrapped devices—especially those containing relatively high amounts of gold, silver, or copper. Large nonprofits like Goodwill also offer electronics recycling services. Many of these organizations handle the hard work of separating components from used devices, then sell the individual parts to industrial recyclers.