Invention Turns our Electronic Waste into 22-carat Gold Nuggets Instead of Toxic Trash

When a slice of this sponge meets a beaker filled with dissolved circuit boards, gold ions rush toward the proteins and cling tightly.

SEATTLE (Scrap Monster): The thin line of gold behind every tap, swipe, and click on our electronic devices rarely enters daily conversation, yet the metal keeps digital life running, then eventually turn into landfills full of toxic e-waste.

From the contacts in a phone jack to the chips inside a smartwatch, gold moves electrons smoothly and shrugs off corrosion.

Mining more, however, blasts mountains, drains rivers, and spews carbon. With the global appetite for electronics still climbing, attention has turned to the growing junkyard of cast‑off gadgets.

E‑waste is now the quickest‑rising waste stream on the planet – roughly 63 million short tons in 2024 according to United Nations estimates – and only a small share gets recycled in certified facilities.

Most of our old electronics end up in landfills or backyard workshops, which then leak metals into the groundwater, creating toxic brews. A cleaner strategy is to reclaim precious metals safely before our devices make their way into the garbage heaps.

Cheese, e-waste, and gold

A research team is now working to change that script. Professor Raffaele Mezzenga at ETH Zurich and senior scientist Mohammad Peydayesh assembled colleagues in search of a simpler tool than acid vats or cyanide baths. Their unlikely inspiration bubbles up in cheese factories.

Cheese makers separate curds from whey, leaving behind nearly nine pounds of watery by‑product for every pound of cheddar. Whey is rich in proteins that twist into hair‑thin amyloid fibrils when warmed in acid.

The Zurich group realized those fibrils could be coaxed into a feather‑light sponge that prefers gold over the other metals lurking in shredded phones and laptops.

Adding a cheesy twist to golden e-waste

The researchers stirred the fibrils into a gel, then dried it into an aerogel – think Styrofoam’s airiness on a nanoscale. Microscopic pores criss‑cross the material, offering miles of surface area inside a crumb‑sized cube.

When a slice of this sponge meets a beaker filled with dissolved circuit boards, gold ions rush toward the proteins and cling tightly.

Early trials showed the aerogel collecting a far higher share of gold than plastic resins that recyclers often use. Better yet, the process skips noxious solvents.

Water, moderate heat, and the natural chemistry of protein do the heavy lifting, which slashes both hazard and cost.

From e-waste ions to gold nuggets

Pulling ions from solution is useful; turning them back into solid metal is crucial. The Zurich group warmed the loaded sponge until the gold ions shed their charge and merged into shimmering flakes.

Heating continued until the flakes fused into a nugget weighing roughly 450 milligrams. Chemical analysis showed the lump was 91 percent gold and 9 percent copper, again hitting the mark for 22 carats.

This step also freed the protein skeleton. Burned away under controlled heat, the whey‑derived matrix leaves no synthetic residue, easing cleanup. Conventional resin beds cannot claim the same neat exit.

Courtesy: www.earth.com