The Wassa mine and oxide ore mill are located in the Wassa East District, in the Western Region of Ghana. Golden Star Wassa Ltd. (GSWL) owns the rights to mine the Wassa, Benso and Hwini-Butre concessions. Golden Star Resources Ltd. (Golden Star) owns a 90% interest in GSWL, with the Government of Ghana owning the remaining 10%.
The Wassa open-pit operations commenced in 2005 and the Wassa underground mine achieved commercial production in January 2017. In early 2018, Wassa transitioned into an underground-focused operation.
Gold mineralization at Wassa is structurally controlled and related to vein densities and sulphide contents. The mineralization is subdivided into several domains that each represent discontinuous segments of the main mineralized system, and the domains include the F Shoot, B Shoot, 242, South East, Starter, 419, Mid East and Dead Man’s Hill. Golden Star’s current primary underground mining targets are the F Shoot and the B Shoot.
The underground mine design utilizes a twin decline access from the base of the open pit, with the capacity to support a production rate of 5,000 tonnes per day. The mining method is sublevel open-stoping using unconsolidated waste backfill, with conversion to cemented paste backfill occurring in 2020. Mining is undertaken using trackless, diesel powered equipment including twin boom jumbos for development and long-hole drills for production drilling, and mined material is trucked to surface through a combination of 17 tonne loaders and 40 tonne trucks. Ore is treated in a carbon-in-leach (CIL) mill with a capacity of 7,400 tonnes per day.
In May 2015, Royal Gold’s wholly-owned subsidiary, RGLD Gold AG, acquired a $130 million gold stream from a wholly-owned subsidiary of Golden Star Resources Ltd. (Golden Star), which was increased by $15 million to $145 million in December 2015. This stream included production from Golden Star’s Wassa, Prestea and Bogoso mines. Effective September 30, 2020, upon the sale of the Prestea and Bogoso mines by Golden Star, RGLD Gold AG and Golden Star separated the stream agreement to provide for a separate stream agreement for the Wassa mine.
RGLD Gold AG owns the right to purchase 10.5% of the gold produced from the Wassa mine until the delivery of 240,000 ounces, upon which the stream percentage will decrease to 5.5% for the remaining life of mine. The cash purchase price for gold is 20% of the spot price of gold per ounce delivered until the delivery of 240,000 ounces, and 30% thereafter. Payable gold is calculated as 99.5% of contained gold in doré.
*Detailed information on our interest can be found on the Portfolio Asset Summary table