Saturday 1 April 2023

Scientists develop way to extract metals from mining waste using engineered microorganisms

 Billions of dollars’ worth of precious metals are hiding in the leftover waste, known as tailings, from mining operations. And scientists are figuring out how to extract them for profit.

A Burnaby-based (Vancouver area of British Columbia, Canada) company called Tersa Earth Innovations says it is using modified microorganisms to filter out valuable metals like copper and gold from the discarded waste material, which was thought to be worthless.

It turns out that copper and gold comprise the majority of the metals found in tailings at 46 percent and 21 percent, respectively. Up until now, however, there was no known way to extract it, hence why it was left behind as waste.

According to Natural Resources Canada, there is about $10 billion worth of precious metals hiding in Canadian gold-mining waste. Toronto-based BacTech has calculated a much higher figure, estimating that $27 billion worth of metals is hiding in just the mine waste from Sudbury, a mining area to the north of Toronto.

“Our uniqueness is two-fold,” said Vikramaditya Yadav, CEO of Tersa Earth. “One is the type of micro-organisms we use.”

Using special bioelectrical fuel cells, Tersa Earth’s process causes microorganisms to generate an electric current that removes the dissolved metals from the waste product. This is done using a continuous flow process rather than the batch process method used by various other companies.

“So we have specifically engineered these microorganisms to behave in a particular way,” Yadav further revealed. “The second is the way in which we have assembled and constructed our system that allows them to be operated in a continuous manner.” 

Billions in hidden value lurking in old metal mines – is this a new gold rush?

BacTech’s extraction methods are similar in that the company also uses bacteria to pull precious metals out of the waste from Sudbury mines. This differs from the chemical-based solutions being used by companies like Phoenix Tailings, which is trying to do the same thing but in a different way.

When a mine is orphaned, meaning it is no longer operational, the companies that exploit their tailings get to keep all the value they extract – at least in Tersa Earth’s case. For mines that are still active, these companies aim to license the technology using a profit-sharing framework.

Since money is everything in today’s world, this new gold rush is making millionaires with the help of life sciences that are closing the technology gap, allowing for more extraction of profits from the earth.

“That entire toolbox is synthetic biology,” Yadav said. “The way in which we are contemplating and using systems did not exist in its current form as recently as 10 years ago. It has really flourished because of enabling developments in the life sciences.”

As for mining in general, demand is high but interest in expanding is not. BMO Capital Markets released a report showing that mining companies are opting to return money back to shareholders rather than build new mines.

Even though the “green” industry is reliant upon earth metals, the industry is scaling back rather than expanding forward. What do the mining companies know that the rest of the world does not about the green revolution and its prospects for the future?

“Imagine that – recycling actually works,” wrote one sarcastic commenter about the prospect of recycling tailings waste and turning it into usable metals through synthetic biology. “What will they think of next?”

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