Gold can be extracted from electronic waste with a new method

A new method allows gold to be profitably extracted from electronic waste.

A new method allows gold to be profitably extracted from electronic waste.

We live in a technological world that requires a very wide variety of chemical elements to manufacture all types of components, circuits and electronic devices. A mobile phone contains silicon, aluminum, iron, phosphorus, gallium, antimony, lead, copper, tantalum, silver and even gold.

Here’s an amazing fact: More than 300 tons of gold is used in electronic products every year. Which turns the recycling of electronic devices into a real “urban mine”. Whereas the percentage of gold in your computer circuit board is between 200 to 250 grams per ton. We can find 300 to 350 grams of gold per ton in mobile phones., This means that “electronic waste mining” is clearly more profitable than traditional gold mining because “to obtain one kilo of gold, three to four Tons of smartphones are enough.”

Despite this, there is so much wealth hidden in the garbage 53.6 million tonnes of electronic waste who were born in 2019 Only 17.4% was recycled, the rest is thrown away, wasted and becomes a global ecological problem. By 2030, approximately 80 million tons of electronic waste is expected to be generated and we urgently need more effective ways to recover these materials before they end up in giant landfills.

That’s why a recent study published in the journal Advanced Materials by a team of researchers at the Polytechnic University of Zurich (ETH Zurich) is so interesting. An innovative way to recover gold profitably Electronic waste when it reaches the end of its useful life.

Scheme of gold recovery process from electronic waste using by-product of food industry.  Pedayesh et al.  doi:10.1002/adma.202310642.Scheme of gold recovery process from electronic waste using by-product of food industry.  Pedayesh et al.  doi:10.1002/adma.202310642.

Scheme of gold recovery process from electronic waste using by-product of food industry. Pedayesh et al. doi:10.1002/adma.202310642.

In their project, the researchers removed metal parts from 20 old computer motherboards and dissolved them in an acid bath to ionize the metals and separate them into positive and negative ions. They then used a fiber sponge that attracted the gold ions and stuck to them. “While other metals (such as copper or iron) were also absorbed by the sponge, it turned out that gold stuck to it more efficiently.”

The next step was to heat the sponge which converted the ions into gold pieces which eventually melted into nuggets with a mass of about 500 mg. After analyzing this nugget they discovered that it was Composed primarily of gold (90.8% by weight) reflecting the great purity of gold obtained, corresponding to 21 or 22 carats,

With their article, the Swiss researchers have demonstrated the commercial feasibility of this new method, taking into account both the acquisition costs of the source material and the energy costs required for the entire process. The findings show that “the total cost of extracting one gram of gold from electronic waste is 50 times less than the value of the recovered gold.”

Even better: this method This is also appropriate from environmental point of view. Because conventional activated carbon is used to recover the gold it produces only 116 grams of carbon dioxide, while the carbon footprint of the sponge is much lower, producing only about 87 grams of greenhouse gases in total… which is The volume is very small compared to traditional mining.

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Scientific references and further information:

Paydayesh, Mohammad, et al. “Gold recovery from e-waste by food-waste amyloid aerogels”. Advanced Materials (2024) DOI:10.1002/adma.202310642.

Fabio Bergamin “Turning Trash into Gold” ETH Zurich

(TagstoTranslate)Electronic Waste(T)Bronze Age

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