Diavik to spend $40M mining below A21 pit, extending life

Diavik diamond mine owner Rio Tinto will spend $40 million to begin mining below the A21 open pit, likely extending the NWT mine’s life to at least early 2026.

Thursday’s announcement adds about a year to the operating life of Diavik, which was the second diamond mine to come on-stream in the Northwest Territories when production began in 2003.

The investment is a boost for Yellowknife’s economy, which has relied on diamond mining for decades, and is the latest demonstration of additional life being eked out of the territory’s three operating diamond mines. Arctic Canadian plans to experiment with underwater mining crawlers to extend the neighbouring Ekati mine’s life.


Open-pit mining at A21, an expansion that opened in 2018, recently concluded.

Rio Tinto says $40 million will start a first phase of underground mining below the pit, with a second phase at extra cost to be put forward for approval in 2024.

“Diavik is now expected to end commercial production in the first quarter of 2026,” the company stated.

Phase one below A21 is expected to produce an extra 1.4 million carats, with phase two providing another 0.8 million carats.

“This is good news for our employees, partners, suppliers and local communities in the Northwest Territories,” said Sinead Kaufman, Rio Tinto Minerals’ chief executive, in a press release.


Rio Tinto said existing employees and contractors will be moved from other areas of the mine to work on the construction and production phases of the underground project.

“Rio Tinto’s decision to support the underground development of the A21 pipe was prefaced on compelling industry fundamentals, our proven capacity to safely develop diamond mines in extreme conditions and a track record in competing successfully in the global diamond industry,” Kaufman was quoted as saying.