Produced by: Mohsin Shaikh
That old phone in your drawer? It could contain 22-carat gold—most of which ends up buried in landfills every year.
E-waste holds more gold per ton than mined rock. Up to 400 grams per ton—yet 80% of global e-waste remains unrecycled.
Traditional gold recovery uses mercury or cyanide—methods that poison ecosystems while chasing precious metal.
ETH Zurich scientists found a cleaner way: a sponge made from cheese industry waste traps gold ions from dissolved electronics.
The sponge is made from whey protein fibrils, turning dairy leftovers into a high-tech tool for sustainable mining.
Once captured, gold is heated into 22-carat nuggets. Twenty circuit boards can yield nearly half a gram of pure gold.
This spongey, gold-loaded aerogel could shift how the world views “waste” — it’s not garbage, it’s a resource mine.
Combined with other recovery methods, this tech could lead to smarter, more sustainable electronics recycling worldwide.
This eco-breakthrough is more than a novelty—it redefines e-waste as a goldmine and a path to cleaner tech practices.