Giga Metals, a Canadian miner, has said it is committed to making the Turnagain nickel project carbon-neutral.
The company announced the results of tests at the University of British Columbia this week.
With an average absorption rate of 2.7kg CO2 / m2 / year for the controlled sample, 900,000 tonnes of CO2 may be sequestered over the life of the mine, or 0.72 tonnes of CO2 saved for each tonne of nickel produced.
The second sample showed a sustained 25% increase in the carbon sequestration rate, which increased to three times the long-term average during optimal humidity and mixing.
The principle of the test is that carbon dioxide is absorbed by exposing tailings or other waste rock to the atmosphere, which converts the host rock minerals into carbonate minerals and traps the carbon dioxide.
Tests show that only about 10% of brucite has been consumed in the sequestration reaction after one month, and the reaction continues, and the sequestration may increase over time if atmospheric or dissolved carbon dioxide continues to be exposed.
This initial rate would make Turnagain a carbon neutral project if an electrified transport fleet were available, due to seasonal variations and management strategies that may cause CO2 sequestration rates to vary.
Martin Vydra, Giga Metals president, said in a media statement: "We now have the data to support our construction of the world's first truly carbon-neutral nickel mine.
"This undeveloped nickel mine is the only one in North America focused solely on the Class I and battery feedstock markets, and our focus on low carbon and other ESG principles will make us an ideal source of battery metals for electric vehicles."
Located approximately 65 km east of the community of Dease Lake in north-central British Columbia, Turnagain is expected to produce 33,000 tonnes of nickel per year, with a maximum of 45,000 tonnes per year over the 37-year life of the mine.
