Johannesburg - De Beers, the world’s biggest diamond
producer by value, says it could operate a carbon-neutral mine within half a
decade.
The Anglo American unit plans to store carbon-dioxide in
kimberlite rock -- a type of ore best known for containing diamonds, but which
also naturally reacts with carbon to remove it from the atmosphere. By
accelerating that process and using readily-available waste rock, De Beers
could offset the emissions from its mines, according to Evelyn Mervine, who’s
leading the research project for the company.
While mineral carbonation isn’t a new idea, kimberlite
offers ideal properties for storing very large volumes of carbon, Mervine said.
De Beers has vast amounts of previously mined waste rock stored in so-called
tailings dams above ground at its mines. Depending on how the research
progresses, De Beers could eventually offset more emissions than it produces,
she said.
“There will be key learnings from this that can be used
in larger bodies of rock that can be found throughout the world,” she said.
De Beers is looking at removing carbon dioxide from power
generators at its mines by piping the gas through a fluid that can then be
injected into the kimberlite waste rock and stored safely, Mervine said. It’s
also studying the potential to spread waste rock more thinly to increase carbon
extraction from the atmosphere.
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Carbon capture and storage is seen as key to tackling
climate change, by removing pollution from the atmosphere that would otherwise
be spewed out by power generators and industry. Yet progress in developing the
technology has been slow and expensive.
De Beers estimates it could achieve carbon-neutral status
at some operations within five to 10 years and is already studying the
possibilities at its Venetia mine in South Africa and Gahcho Kue in Canada. The
potential for storage at historic tailings at Debswana in Botswana will also be
assessed, Mervine said.