Allied Gold’s expansion strategy to incorporate more high-grade fresh ore and boost production to 300,000-400,000 oz/y at its 80%-owned Sadiola open-pit mine in Mali is being re-evaluated, and a number of optimisation options are on the table, CEO Peter Marrone told IM on the sidelines of the Future Minerals Forum in Riyadh last week.
Sadiola, also owned 20% by the Mali Government, is currently a circa 200,000 oz/y producing asset processing approximately 80% oxide material through a conventional processing plant with a nameplate capacity of 5 Mt/y.
The company has disclosed plans to double production at Sadiola by the end of the decade. This move will increase throughput and incorporate increased ratios of high-grade, fresh ore. Given that the company has around 10 Moz in resources and over 7 Moz in reserves on its books at Sadiola, it will make it a large-scale, generational asset.
Phase one of this expansion is already in motion and set to come into production by the end of the year. This phase, costing around $62 million, will see the mining company feed up 5.7 Mt/y of ore with a fresh:oxide feed ratio approaching 60:40. The company will achieve this through the addition of tertiary crushing and a ball mill at the front end of one of the lines of the existing CIP circuit.
Phase two, which has already gone through engineering and a feasibility study in 2022, would see the company build a new 8-10 Mt/y CIL plant dedicated to processing fresh ore. It would also involve increasing mining activities to supply ore to the expanded processing facility. The capital expenditure for this second expansion has been estimated at $350-400 million.
At FMF 2025, Marrone told IM that an incremental and progressive step, or “Phase 1.5”, was also being discussed and scoped internally as part of a value optimisation strategy since taking the company public in late 2023. Focusing on building on Phase 1’s upgrades could see the company further debottlenecking and optimising the existing processing plant progressively and organically. The initiative could boost Sadiola’s processing capacity even higher than Phase 1 and potentially improve the projected gold recoveries to levels approaching 85% compared with the 75% levels in the original feasibility study. This concept still requires further test work, engineering, a new feasibility study and signoff from the Government of Mali.
Notably, this optimisation option could provide Sadiola with similar output levels to the original plan but with a more efficient and progressive deployment of capital and progressive increases in production. “The potential to feed additional oxide ore in the following years could also leverage this expanded processing capacity at the mill, providing increased operational flexibility and production levels to Sadiola and, ultimately, increase value to our shareholders,” Marrone said.
