Russian diamond producer Alrosa Group has completed the first phase of a study that examined the ability of kimberlite ores to absorb carbon dioxide (CO₂) from the Earth's atmosphere.

Alrosa's preliminary studies, which were undertaken with leading research centres in Russia, have demonstrated that there is a degree of interaction between kimberlites and atmospheric CO₂. The research is scheduled to last until 2023.

The company noted that the discovery that kimberlites ores can absorb carbon has created an opportunity for diamond mining companies to advance climate initiatives that involve CO₂ capture and storage.

These preliminary studies focused on the chemical processes that take place in spent ore. They included samples of ore from various stages of the mining lifecycle, such as extraction, processing and post-processing storage.

Selected ore samples that had gone through the technological cycle and were then placed in tailings storage tanks for periods of between one month and 10 years were evaluated against original kimberlite samples that had were extracted from the sample of drill core.

Mikhail Dubovichev, head of Alrosa's innovation and technology center, said: "The studies on original diamond ore samples are set to continue until 2023, and we are planning to engage leading geochemical and geological research centres in the process. If future research confirms the preliminary data found, we will have established significant potential for compensating greenhouse gas emissions in diamond mining through the ore's ability to absorb carbon dioxide from the atmosphere. This discovery could mark a new step in the efforts to preserve our planet's ecosystem."

The initial results indicate that the CO₂ absorption potential of the kimberlite ore is comparable to, and in some scenarios several times greater than, the CO₂ emissions of the entire Alrosa Group. This suggests that CO₂ absorption by kimberlites in Alrosa's Udachnaya pipe could be as high as 80kg per tonne of processed ore, which is almost four times greater than the average annual CO2 emissions from Alrosa's diamond production.

Polina Anisimova, chief ecologist at Alrosa, added: "Transport and power generation are the biggest sources of greenhouse gas emissions in diamond mining. Alrosa Group currently generates around 90% of its power from renewable sources, while its logistics function is replacing traditional liquid fuel with natural gas, enabling a structural reduction in greenhouse gas emissions. However, achieving carbon neutrality today merely by upgrading existing production processes is challenging. Alrosa's ambitious carbon neutrality goals can only be met through a combined approach that also includes absorbing CO2 from the atmosphere and offset measures."

Researchers from Alrosa have written an article called ‘Potential for Compensating Greenhouse Gas Emissions from Alrosa Group Enterprises by Carbonisation of Processed Kimberlite' which was co-authored with researchers from the Moscow State Institute of Radio Engineering, Electronics and Automation and the Institute of General and Inorganic Chemistry of the Russian Academy of Sciences. The article has been accepted for publication in the scientific journal Rational Exploitation of Mineral Resources.