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 has been identified as 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 using heap leaching and activated carbon in an ADR plant where gold doré is produced and sent to a refinery. The Gualcamayo mine produced approximately 164,000 ounces of gold in 2016 and Yamana has projected 145,000 ounces of production during the 2017 year (75,091 ounces were produced during the first half of 2017). The Dec. 31, 2016 Proven and Probable Reserves at Gualcamayo contain 754 kozs of gold in 18.2 Mt at a grade of 1.29 g/t (1 g/t cut-off).
Sandstorm has a 1.0% net smelter returns royalty on the Gulacamayo project. The royalty was previously owned by Premier Royalty Inc., a company that Sandstorm acquired in October 2013.