Name of the Project
Wassa underground gold project.
Location
Ghana.
Client
Golden Star Resources (GSR).
Project Description
The project involves the development of an underground mining operation at the currently operating Wassa openpit mine.
Access development to the underground stoping areas will be through a twin decline system from the north-east wall of the openpit.
The twin decline system will ensure efficient ventilation during the early underground stages and will obviate the requirement for a raisebore ventilation raise and escape way close to the start of the decline. The main decline will be 5.8 m high and 5.2 m wide and will be developed using standard trackless mechanised mining methods. The upper stopes will be mined using longitudinal longhole open stoping with waste rockfill. This will allow for efficient early production before a cemented rockfill preparation and delivery system is installed. The Wassa openpit will eventually descend to the top of these upper stopes, but only towards the end of the life-of-mine.
In the deeper, wider areas of the deposit, a transverse longhole open-stoping method will be used. A primary-secondary mining sequence will be implemented, with the primary stopes filled with cemented rockfill and the secondary stopes with waste rockfill. The overall stoping sequence will be bottom-up to reduce the incidence of sill pillar development. New surface infrastructure to support the underground mining will be built, including electrical power supply from the grid, with backup genset support, and surface mechanical and electrical workshops. At steady-state production, the Wassa underground mine is expected to produce an average of about 2 000 t/d across the life-of-mine.
Jobs to be Created
Not stated.
Net Present Value/Internal Rate of Return
The project has a net present value, at a 5% discount rate, of $176-million and an internal rate of return of 83% at a $1 200/oz gold price.
Value
Preproduction incremental capital expenditure for Wassa underground is estimated at $39-million.
Duration
Not stated.
Latest Developments
Commercial production has been achieved at GSR’s Wassa underground project.
Since GSR blasted the first stope at the project in July 2016, the company has been mining development and stope ore in the F Shoot.
Gold production is expected to continue to ramp up during 2017 as GSR’s mining operations begin to access the B Shoot, which is a higher-grade arear of the Wassa underground orebody.
The company plans to begin longitudinal stoping of the B Shoot in the first quarter of 2017, with the larger transverse slopes expected to be accessed in the third quarter of this year.
Key Contracts and Suppliers
Not stated.
On Budget and on Time?
The project construction, including the installation of ancillary infrastructure, is essentially complete and operational, in accordance with GSR’s planned schedule and budget.
Contact Details for Project Information
Golden Star Resources VP: investor relations Angela Parr, tel +1 416 583 3800 or email investor@gsr.com.