Mine copper without destroying the planet? London-based project gives scientists hope

Experts hope research can create greener methods of extracting the metal vital for renewable energy revolution and boom in electrical devices

It is the key ingredient of bronze, the alloy that helped create some of the world’s greatest civilisations and took humanity out of the stone age on its way to modern times. For good measure, the metal is invaluable for electrical wiring, plumbing and industrial machinery. We owe a lot to copper.

But the metal now faces an uncertain future as manufacturers prepare to expand its use to make the electric cars, renewable power plants and other devices that will help the planet move towards net zero. Unrestricted extraction could cause widespread ecological devastation, scientists have warned.

The issue is to be the prime focus for the new Rio Tinto Centre for Future Materials, based at Imperial College London in partnership with several international university groups. A total of $150m has been set aside for its first 10 years of operations.

“The world needs to electrify its energy systems, and success will absolutely depend on copper,” materials scientist and Imperial vice-provost Prof Mary Ryan, one of the centre’s founders, told the Observer last week. “The metal is going to be the biggest bottleneck in this process. So, in setting up the centre, we decided copper would be the first challenge that we dealt with – though we will turn our attention to other materials in future.”

This point was backed by Dr Sarah Gordon, the centre’s co-director. “Our first aim is to find new, responsible ways to source metals – in particular copper. Can we extract it without disturbing rocks at all? Or could we use viruses and bacteria to harvest copper? These are the first crucial questions the centre aims to answer.”

Copper has become essential for powering devices ranging from smartphones to electric vehicles because it transmits electricity with minimal loss of power and is resistant to corrosion. Around 22m tonnes of copper were mined in 2023, a 30% increase from 2010, and annual demand will reach around 50m tonnes by 2050, say analysts.

Such an output will have enormous environmental consequences because copper mining uses acids that poison rivers, contaminate soil and pollute the air. Producers such as Peru, Chile and the Democratic Republic of the Congo have seen natural habitats destroyed, wildlife populations wiped out and human health damaged near mines. Deep-sea mining has been proposed, but the idea horrifies marine biologists, who say such enterprises would devastate sea life.

The aim of the new centre is to find ways round these problems and help provide the materials the world will need to reach net zero. It is funded by the mining group Rio Tinto and hosted by Imperial College London in partnership with the University of British Columbia in Vancouver, the University of California, Berkeley, the Australian National University and the University of the Witwatersrand, Johannesburg.

One key project is seeking new ways to mine copper. “We typically extract it from minerals that have crystallised out of very saline, copper-rich brines,” said Professor Matthew Jackson, chair in geological fluid dynamics at Imperial College. “However, this process requires huge amounts of energy to break open the rocks and bring them to the surface and also generates a lot of waste as we extract copper from its source ores.”

To get round this issue, Jackson, working with international partners, has been searching for underground sites where copper-rich brines are still in liquid form. These brines are created by volcanic systems which can, crucially, provide geothermal energy for extraction.

“That means we can extract the copper by pumping the brines to the surface via boreholes – which is relatively easy – and also use local energy to power the mine itself and possibly provide excess energy for nearby communities,” Jackson said. “Essentially, we are seeking to build self-powered mines and have already pinpointed promising sites in New Zealand, and there is potential to explore conventionally barren areas such as Japan.”

Cover photo:  Biological approach to copper … Imperial College researchers Franklin Keck, left, and Ion Ioannou. Photograph: Handout