The London-based firm will work with international scientists to investigate the storage potential of kimberlite, a rare type of rock that remains after diamonds are removed from the ore. Scientists estimate that kimberlite tailings offer ideal properties for storing carbon, which could offset up to 10 times the emissions of a typical mine.

De Beers Group’s project lead for the initiative Dr Evelyn Mervine said: “This project offers huge potential to completely offset the carbon emissions of De Beers’ diamond mining operations.

“The research is in its early stages and it may take some time before it is economically or practically achievable to tap into this full storage potential. However, even just tapping into a small amount could greatly reduce the net emissions at many of our mine sites in the near future, and possibly lead to carbon-neutral mining at some sites within the next five to ten years.

“As technology improves over time, more and more carbon could feasibly be stored in kimberlite tailings, meaning we could ultimately offset more emissions than we are producing.”

Energy storage assessment studies are currently underway at the Venetia Mine in South Africa and Gahcho Kué Mine in Canada, with further research to continue through to 2018.

De Beers believes the work being undertaken by the project team could have significant applications for the wider mining sector, as the ideal carbon storage characteristics of kimberlite rock are also found in rocks mined for other commodities, such as nickel and platinum.

The company’s chief executive Bruce Cleaver said: “By replicating this technology at other mining operations around the world, this project could play a major role in changing the way not only the diamond industry, but also the broader mining industry, addresses the challenge of reducing its carbon footprint.”

Sustainable extraction

The mining industry has long been linked to environmental and social harm in developing countries, with pollution and environmental degradation in particular major downsides. With fossil fuels accounting for 77% of the company’s total energy consumption across its mining sites in Botswana, Namibia, South Africa and Canada, De Beers has set out to improve its sustainability impact in recent times.

As highlighted in its latest CSR report released last week, De Beers has set itself a list of key commitments for 2020: to reduce water usage by 20%, energy use by 8% and carbon emissions by 9%. While the report does not confirm whether De Beers is on course to meet these targets, it does claim that progress against these goals has resulted in total savings of £8.2bn since 2014.

“It is undeniable that mining leaves behind a social and environmental footprint,” De Beers chairman Mark Cutifani said. “We have to ensure the socioeconomic benefits from what we do have a sustainable impact and are a catalyst for growth and national benefit.”

Water scarcity is a major problem in South Africa, Botswana and Namibia, the three countries that collectively account for more than 96% of the rough diamonds mined by De Beers. To tackle the issue, the firm has developed a new diamond sorting system which improves recovery rates and requires less than 1% of the water consumption in the current system. These types of innovative solutions have helped De Beers reduced water usage by 0.3 billion litres in 2016, the firm said.

The report also highlights that a biodiversity and conservation programme has linked seven diverse sites covering 145,000 hectares across southern Africa, an area five times larger than that affected by the company’s mining activities.

George Ogleby

Action inspires action. Stay ahead of the curve with sustainability and energy newsletters from edie