April 17, 2024

Innovative Method Uses Food Industry Byproduct to Recover Gold from E-Waste

Professor Raffaele Mezzenga from ETH Zurich has successfully recovered gold from electronic waste using a byproduct of the cheesemaking process. Mezzenga’s team, with their sustainable approach, has found a new method that is not only efficient and cost-effective but also environmentally friendly compared to traditional methods that are energy-intensive and use toxic chemicals.

The process involves creating a sponge made from a protein matrix by denaturing whey proteins under specific conditions to form protein nanofibrils. This sponge is then utilized to extract gold from electronic waste. In a recent experiment, the team extracted metal parts from 20 computer motherboards and used the protein fiber sponge to selectively adsorb gold ions, demonstrating its efficiency over other metal ions.

Following adsorption, the researchers heated the sponge to reduce the gold ions into flakes, which were then melted down to obtain a gold nugget weighing approximately 450 milligrams. The purity of the recovered gold was measured at 91%, equivalent to 22 carats. The economic feasibility of this technology is promising, with the total costs of procurement and energy significantly lower than the value of the recovered gold.

Mezzenga and his team plan to advance the technology for market readiness, exploring various sources of electronic waste and industrial byproducts for gold extraction. Besides electronic waste, potential sources include waste from microchip manufacturing and gold-plating processes. Moreover, they aim to investigate the use of other protein-rich byproducts or food industry waste to manufacture the protein fibril sponges.

Mezzenga states, “The fact I love the most is that we’re using a food industry byproduct to obtain gold from electronic waste.” This innovative method not only transforms waste products into valuable resources but also embodies sustainability at its core. The team’s breakthrough serves as a significant step towards a more sustainable and eco-friendly approach to recovering precious metals from electronic waste.

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1. Source: Coherent Market Insights, Public sources, Desk research
2. We have leveraged AI tools to mine information and compile it