Rio Tinto reported an 18% year-on-year increase in diamond output for the fourth quarter of 2023, reaching 775,000 carats.
The rise follows efforts to ramp up production after addressing ground subsidence issues and transitioning to underground mining at the Diavik mine’s A21 pit.
The miner completed the first phase of underground development at A21, where open-pit operations concluded in late 2023.
Rio Tinto is now scaling up processing in the area to achieve commercial production. Elsewhere within the deposit, production resumed after a temporary shutdown in July due to ground instability.
Carat recovery improved significantly, climbing 43% compared to the previous quarter.
Despite the strong fourth-quarter performance, full-year production declined 17% to 2.8 million carats, attributed to a 25% drop in ore processed, which totaled 1.3 million carats.
Diavik remains Rio Tinto’s sole diamond mine following the closure of the Argyle deposit in November 2020.
The company increased its stake in Diavik to 100% in November 2021 after acquiring its joint-venture partner Dominion Diamond Mines’ share.
In 2023, Rio Tinto sold its 75% stake in the Fort à la Corne diamond exploration project in Saskatchewan to Star Diamond Corporation to focus on metals and minerals. The company also continues diamond exploration efforts in Angola.
Rio Tinto has invested $40 million to transition to underground mining at A21, a move expected to add over 2 million carats of rough diamonds and extend the mine’s life until early 2026.
However, the miner has not provided production guidance for 2025.
