BHP plans to keep critical mineral mines running without adding to emissions by capturing carbon from mine waste and turning it into rock.

Canadian carbon mineralisation company Arca announced on Wednesday a trial with BHP that will use tailings at the Mount Keith open pit nickel mine near Wiluna in Western Australia.

The trial to clean up the extraction of nickel, a critical metal for batteries to power electric cars and grid-scale energy storage, is the first such pilot project at an active mine.

The clean energy transition will require more mining, not less, of key minerals, according to the International Energy Agency. 

But auto and battery makers will be required to trace and disclose the sources of their supplies from mine to factory.

Resource-rich economies such as Australia and Canada want to grab market advantage in more sustainable mining as consumers and manufacturers outside China demand products with higher environmental and labour standards.

Canada’s Minister of Natural Resources Jonathan Wilkinson said the “air-to-rock” project is an example of the technology needed to accelerate towards a net-zero emissions future by 2050, while immediately reducing emissions.

The trial at BHP’s mine has been backed by a Canadian grant of $A1.39 million from the British Columbia Centre for Innovation and Clean Energy (CICE). 

“There is already far too much carbon dioxide in the atmosphere,” Arca CEO Paul Needham said.  

“Support from CICE gives us an opportunity to rapidly pilot our negative emissions technologies with companies that produce critical metals for the clean energy transition,” he said.

The 18-month project is designed to demonstrate the method of using the waste from critical mineral mines can be scaled up to work safely as part of mining operations.

Low-grade ore is mined from Mount Keith, while high-grade nickel sulphide ore is mined at BHP’s Cliffs and Leinster underground mines, with most of it shipped into the global battery supply chain.

According to Arca, mine tailings have the potential to remove gigatonnes of carbon from the atmosphere and serve as a massive “carbon sink”.

Using rovers, surface manipulation technology and machine learning, the technology can measure the carbon as it is captured and stored.

But critics say investment should be poured into clean energy investments and new industries, not technology that is yet to be proven on a commercial scale.

–AAP