Turning E-Waste into Gold: The Revolutionary Process That’s Changing the Recycling Game

BY CHARLIE A | 05 JUNE 2024

Imagine turning discarded electronics into pure gold—this isn't a scene from a sci-fi movie, but a groundbreaking reality. As e-waste mounts globally, innovative methods to extract valuable materials from old gadgets are becoming more crucial. Researchers at ETH Zurich have developed a sustainable, efficient method to recover gold from electronic waste, using a surprising ingredient from the food industry: whey, a by-product of cheese making. This blog delves into this fascinating process and its broader implications for the environment and economy.

The E-Waste Challenge: A Growing Problem

E-waste, or electronic waste, is the world's fastest-growing waste stream. According to the United Nations Environment Programme, an estimated 50 million tonnes of e-waste are produced globally each year. Despite containing valuable materials like gold, only 20% of e-waste is formally recycled, with the rest ending up in landfills or incinerated, causing significant environmental harm.

Forty tons of e-waste are discarded into landfills.

The Golden Opportunity: Why Extract Gold?

Gold is a non-renewable resource with extensive applications in electronics, aerospace, medicine, and more. As the demand for gold rises, traditional mining methods become less sustainable. Extracting gold from e-waste not only recycles this precious metal but also reduces the need for environmentally damaging mining practices .

The Innovative E-waste into Gold Process: Cheese Whey to Gold Nuggets

Researchers at ETH Zurich have developed a process to extract gold from e-waste using an amyloid nanofibril (AF) aerogel derived from whey. Here’s how it works:

1. Initial Cleaning: The motherboard is cleaned and unwanted components are removed.

2. Dissolution: The cleaned motherboard is dissolved in an acidic bath called aqua regia .

3. Gold Absorption: The AF aerogel, acting like a sponge, absorbs the gold ions from the solution.

4. Gold Recovery: The aerogel is dried, combusted, and mixed with borax, then melted and cooled to form nearly pure gold nuggets .

This diagram illustrates the process by which gold ions attach to a sponge made of protein fibrils, enabling the separation of gold from other elements. ETH Zurich/Advanced Materials

This method is not only efficient but also significantly reduces the carbon footprint compared to traditional methods using activated carbon. Recovering 1 gram of gold requires only 5.26 grams of AF aerogel, compared to 15.15 grams of activated carbon, cutting the carbon footprint by 25% .

Beyond Gold: Potential for Other Metals

While gold is the focus, this method shows promise for extracting other valuable metals from e-waste, including platinum, palladium, silver, and exotic rare earth metals. This versatility could revolutionize how we handle electronic waste, making it possible to recover a wide range of valuable materials efficiently.

Economic and Environmental Impact: A Win-Win

The economic benefits are clear. For every dollar spent on the extraction process, approximately $50 worth of gold is recovered. Environmentally, the process uses a by-product of the dairy industry, which itself is often wasted, adding another layer of sustainability.

Global Applications: Scaling the Technology

The Royal Mint in the UK is already exploring similar techniques to recover precious metals from e-waste. Their process, developed with Canadian start-up Excir, extracts 99% of gold from circuit boards at room temperature, using a recyclable chemical solution. This scalable method aims to process 90 tonnes of circuit boards per week, reducing the need for raw material mining and cutting greenhouse gas emissions.

Conclusion: The Future of E-Waste Recycling

As we face an ever-growing e-waste problem, innovative solutions like these offer a beacon of hope. By turning electronic waste into valuable resources, we can reduce our environmental footprint, recover critical materials for new technologies, and pave the way for a more sustainable future. The cheese whey to gold process is a remarkable example of how science and sustainability can come together to solve some of our most pressing challenges.

Call to Action: Join the Revolution

Stay informed about the latest advancements in e-waste recycling and support sustainable practices. Together, we can make a difference in reducing e-waste and preserving our planet's valuable resources. Follow our blog for more updates on innovative recycling techniques and eco-friendly solutions.

Sources

1. IEEE Spectrum

2. New Atlas

3. BBC Future

4. Mezzenga, Raffaele. "Researchers Turn Electronic Garbage Into Gold." ETH Zurich.

5. Mezzenga, Raffaele. "Pulling gold out of e-waste suddenly becomes super-profitable." ETH Zurich.

6. Messenger, Hayley. "The gold jewellery made from old phones." Royal Mint, Cardiff.

7. Loveridge, Mark. "A chemical solution for e-waste." Royal Mint, Cardiff.