Turning Tech Trash Into Literal Gold

Urban mining of gold is now a possibility, necessity even, as piles of tech rubble become common modern “ores” from which innovators and scientists creatively extract precious metals.

Turning Tech Trash Into Literal Gold

The green metallic innards of outdated television sets, phones and computers may look like trash to most people but to Dr Will Barker, they are worth their weight in gold. The New Zealander founded cleantech company Mint Innovation, which harnesses microbes such as algae, bacteria and fungi, all of which suck up valuable metal components like copper and gold from electronic waste.

The start-up expects to recover a variety of precious metals worth up to US$10,000 ($14,000) from each tonne of crushed and powdered e-waste supplied by Remarkit, a recycler in Wellington. If the numbers add up, there is clearly money to be made by this modern metal-mining.

Barker explains, “Globally, about 45 million tonnes of e-waste are generated per annum. The metallic value alone in e-waste is said to be almost US$50 billion. This includes US$22 billion in gold, found primarily in printed circuit boards. That ‘urban ore’ is attractive feedstock for us.”

Likewise, research has shown that these modern, gold-digging facilities can be far more profitable than traditional mining. It is possible to extract 100 grammes of gold per tonne from electronic scrap compared to just eight grammes per tonne from mining-ore concentrate.

Will Barker, CEO of Mint Innovation, has found another way to dig for gold.

The New Zealand government is finally taking notice too. While Mint Innovation has been successfully running its modest metal-extracting laboratory in Auckland for about a year now, a recent grant from the Ministry for the Environment’s Waste Minimisation Fund helps give the company a final push to scale up. Currently, it is constructing a pre-commercial demo plant nearby its lab, which will be open for recyclers from around the world to visit.

Though Barker and his team aren’t the first players to have unearthed the shiny opportunity of plucking out gold from e-waste, they are the first to develop a bio-refinery that uses proprietary microorganisms to bind and concentrate metals under environmentally benign conditions. Mint Innovation’s cyanide-free, low-carbon process is a far cry from most recovery plants, especially those in developing countries, where mishandling during processing has had acute impacts on quality of life. “Everyone knows that e-waste is a very toxic waste stream, containing lead, cadmium and mercury. There are very few looking to do something about it correctly too. Even at an individual level, the majority of people have a drawer full of obsolete electronics because they simply don’t know how to dispose of them,” Barker says.

And he’s right. An estimated 75 percent of mobile phone users don’t throw their phones away. Of the approximately 350,000 mobile phones that do get chucked into the bin on a daily basis, only less than 20 percent of those trashed tech get recycled. The rest ultimately end up in landflls or incinerators — and that’s kilogrammes of gold, gone forever. Mobile phones alone, on average, contain 200 grammes of gold per tonne.

This tiny gold bar could be hiding inside your smartphones. If you had a literal tonne of them, that is.

Still, it’s not easy trying to recover the miniscule quantities of gold and other precious metals from electronics. Many companies have spent years trying to find the magic solution. It is difficult for processors like smelters to recover the full value, as it is energy and capital intensive to incinerate circuit boards to liberate gold and other precious metals, which by the way, releases cancer-causing gases such as dioxins. A large percentage of the gold in e-waste sent to smelters is never recovered anyway.

That being said, there is now an increasing number of new, innovative companies across the globe similar to Mint Innovation that are tackling the problem from several different angles. In Finland, researchers have developed a biological filter made of mushrooms that could recover as much as 80 percent of the gold in e-scrap. Comparably, a new fungus type was recently discovered in Western Australia that can extract small quantities of gold from soil, which could prove useful in recovering a higher amount of gold from e-waste. In Singapore, integrated waste management firm Blue Planet Environmental Solutions tactically acquired Liverpool’s Smart Creative Technologies to tackle Asia’s growing e-waste problem.

Jonathan Quinn, founder of Smart Creative, says, “In Asia, there are many unsafe and unethical recycling techniques and mining practices that have a significant negative impact on society. We at Smart Creative have developed a clean, ethical and environmental solution which recovers 99 percent of all materials. This is achieved by using nonhazardous chemicals which gives higher yield and returns compared to traditional technologies.”

Smart Creative also uses ultrasound agitation to reduce the processing time by up to 20 times. Furthermore, the company’s recovery system for lead, among other metals, from printed circuit boards and cathode-ray tubes, provides a local, sustainable alternative to treating e-waste that eliminates the need and high cost of exporting e-waste.

Isolating gold from other detritus is no easy task.

Yet, the existing export trade routes, both licit and illicit, for electronic waste materials are highly profitable for a few actors, which is a real challenge for clean technology companies, according to Barker. “Our technology threatens to disrupt this by returning valuable metals into the economy where they are collected. While this type of circular economy is strongly promoted by governments and residents, in reality, there are few incentives or drivers to actually make it work.”

Still, recent bans by key e-waste importers such as China, and the increasing awareness of e-waste’s environmental and humanitarian catastrophes, have given rise to the need for innovative technologies offered by companies like Mint Innovation and Smart Creative to address all aspects of this particularly noxious waste stream. And reaching for the gold metal — and medal — is always a winning strategy.