Operator: Chifeng Jilong Gold Mining Co., Ltd.
Location: Western Region, Ghana
Term of Stream: Life of Mine
The Wassa mine and 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. Chifeng Jilong Gold Mining Co., Ltd., owns a 90% interest in GSWL, with the Government of Ghana owning the remaining 10%.
The Wassa mine was originally developed as a 3 million tonne per annum (Mtpa) open-pit heap leach operation with first ore mined in 1998. After approximately one year of production, it became evident that the predicted heap leach gold recovery of 85% in the oxide ore could not be achieved and the operation was shut down. In 2002 Golden Star Resources acquired the property and constructed a 2.7 Mtpa carbon-in-leach (CIL) plant. The Wassa open-pit operations commenced in 2005. In 2017 commercial production was achieved at the underground operation. Both open-pit and underground mining continue to operate.
Access to the underground mine is via declines in the Wassa open-pit, with the capacity to support a production rate of 5,000 tonnes per day. The mining method is sublevel open-stoping with cemented paste backfill. 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 using 40 tonne trucks.
RGLD Gold AG owns the right to purchase 10.5% of payable 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 or 99% in any other form.