The Gualcamayo mine is an open pit and underground heap leach operation that reached commercial production in 2009. Gualcamayo consists of three substantial zones of gold mineralization called Quebrada del Diablo (QDD), Amelia Ines-Magdalena (AIM) and QDD Lower West. QDD is a sediment-hosted disseminated gold deposit while AIM is a sulphide-bearing skarn deposit containing copper, zinc and molybdenum with gold-arsenic mineralization. Porphyry style molybdenum mineralization also occurs at the project.
The process facility at Gualcamayo is designed to treat 24,000 tpd and includes a primary, secondary and tertiary crushing circuit. Gold recovery of approximately 60% is achieved with heap leaching and activated carbon in an ADR plant where gold doré is produced and sent to a refinery.
As of June 30, 2021, Measured & Indicated Mineral Resources, OP and UG exclusive of Mineral Reserves, for Gualcamayo were estimated to total 26.3 Mt at a grade of 1.9 g/t gold for 1.6 Moz gold based on a cut-off grade of 0.2–0.4 g/t for open pit and 0.63–1.85 g/t for underground resources. In addition, Inferred Mineral Resources were estimated at16.1 Mt at a grade of 2.3 g/t gold for 1.2 Moz gold. The Proven & Probable Mineral Reserves for combined OP and UG were estimated at 3.3 Mt at 1.65 g/t gold for 174 koz gold based on a cut-off grade ranging from 0.32–0.52 g/t for open pit and 0.84 g/t for UG.
Mineros S.A. provided updated guidance on mineral resources and reserves.
Mineros S.A. plans to continue making investments in exploration at Gualcamayo to increase the life of the mine.
Yamana announced the sale of the Gualcamayo mine to Mineros S.A. for approximately $85.0 million. Mineros S.A. is a Columbia based gold producer with operations in Columbia and Nicaragua. Gualcamayo produced close to 70,000 ounces of gold during the first three quarters of 2018.