Rio Tinto has started commercial production at phase 1 of the A21 underground mine at its Diavik diamond mine in Canada following the completion of the development and construction.
After the completion of the first phase, Rio Tinto approved phase 2 of the A21 underground project earlier this year, with an additional investment of $17m. The second phase aims to optimise the value of the Diavik mine’s known resources until its closure.
Fully owned and operated by Rio Tinto, the Diavik diamond mine is said to be among Canada’s largest diamond mines by volume of rough diamonds. The mine has produced more than 144 million carats of rough diamonds since operations began in 2003.
Located nearly 200km south of the Arctic Circle at the bottom of Lac de Gras, the mine comprises four diamond-bearing pipes. Currently, the commercial production is expected to end in 2026.
In February 2023, Rio Tinto announced a $40m investment in phase 1 of underground mining below the existing A21 open pit at the Diavik mine.
The A21 underground mine construction encompassed the development of more than 1,800m of underground tunnels to access the orebody and commence production.
Diavik diamond mine chief operating officer Matt Breen said: “The A21 underground operation is positive news for our employees, partners, suppliers and local communities in the Northwest Territories, as it will enable operations to continue through to closure.
“Rio Tinto’s decision to proceed with Phase 2 is a testament to the excellent performance of our Diavik team in successfully developing the underground mine beneath the previously mined A21 open pit.”
According to the mining company, the project reported no lost time injuries after more than 100,000 labour hours were completed over the 20-month development and construction period.
Rio Tinto is also continuing its investment in the closure and remediation works of the Diavik diamond mine site. The company is focusing on progressive reclamation activities, including site clean-up, earthworks, equipment procurement, and other closure readiness initiatives.
