Yamana Gold says it is evaluating the installation of a backfill plant at its Jacobina gold mine in Brazil (pictured) in a move that would reduce the asset’s environmental footprint, as well as extend the life of the operation’s existing tailings storage facility.
The backfill plant would allow up to 2,000 t/d of tailings to be deposited in underground voids, Yamana said in its 2021-2023 guidance and 10-year overview release.
The miner said the construction and operation of a backfill plant would also improve mining recoveries at the operation, resulting in increased conversion of mineral resources to mineral reserves.
Jacobina produced 44,165 oz of gold during the December quarter and an all-time high of 177,830 oz for 2020, the company reported in a separate release.
This was the seventh consecutive year of increasing production at the operation, a trend that is expected to continue in the coming years, Yamana said.
“Successful infill and exploration drilling in the Canavieiras and João Belo sectors during 2020 continues to generate significant growth potential,” the company added.
Production in 2021 is forecast to be in a similar range to the 177,830 oz recorded in 2020, Yamana said.
“The operation exceeded the targeted throughput rate of 6,500 t/d for the Phase 1 expansion, and it continues to identify and implement additional processing plant optimisations to further increase throughput, improve recoveries and reduce costs,” the company said. “Beyond further optimisations, the feasibility study for Jacobina’s Phase 2 expansion plans to increase throughput to 8,500 t/d and raise annual production to 230,000 oz remains on track for mid-2021.”
Yamana’s base case in its 10-year overview also included production from an underground mine at the Canadian Malartic operation in Quebec, Canada. This consists of the East Gouldie, Odyssey, and East Malartic zones, (collectively known as the Odyssey project).
Owned 50:50 by Yamana and Agnico Eagle, the Canadian Malartic open-pit mine exceeded its revised 2020 guidance, producing 568,000 oz of gold (on a 100% basis). Production last year was impacted by COVID-19 related restrictions on mining in Quebec and is forecast to increase in 2021 to 700,000 oz, with all-in sustaining costs projected to decline to $850-$885/oz, from $945/oz in 2020.
The Canadian Malartic open pit will be depleted in the first half of 2023, and waste rock and tailings will be deposited into the pit beginning in 2023, Yamana says.
This coincides with planned first production from the Odyssey South zone at the underground project, with the Upper East Gouldie zone expected to come online in 2027.
The most recent underground mineral resource for the project, which was published in February 2020, showed more than 10 Moz of gold (100% basis), including 9.6 Moz ounces of inferred mineral resources (100% basis) and 830,000 oz of indicated mineral resources (100% basis).
“In the interim, exploration results have been exceptional, improving economics and increasing confidence that the underground project will be a multi-hundred-thousand-ounce annual producer for decades,” Yamana said.
Key development milestones for the underground project over the next three years include the development of a ramp into the Odyssey, East Malartic, and East Gouldie zones, which will allow for tighter definition drilling to further expand the mineral resource base, along with headframe construction and shaft sinking, Yamana said.
A preliminary economic assessment for the project is expected to be completed in February.