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MODERN MINING
June 2016
WEST AFRICA
feature
L
ocated approximately 35 km north-
east of the town of Tarkwa within
the southern portion of the Ashanti
greenstone belt, Wassa – acquired
by GSR in 2002 – is currently an
open-pit operation with the ore being treated
in a CIL plant with a nameplate capacity of
2,7 Mt/a. In late 2014, GSR initiated a Feasibil-
ity Study (FS) to determine the viability of an
underground mine operating in conjunction
with the open pit. The results were announced
in March last year and confirmed the econom-
ic case for the project.
The FS covers both the open-pit and under-
ground operations and essentially constitutes
a mine plan through to 2024. It estimates the
combined gold production from both opera-
tions over this period will average 163 000
ounces a year with the IRR (at a gold price of
US$1 200 per ounce) estimated at 83 % and the
NPV (assuming a 5 % discount rate) at US$176
million. The FS puts the payback period at
3,25 years.
The underground mine – which will exploit
an underground mineral reserve of 5,4 Mt
at 4,26 g/t for 745 000 ounces of gold – is
accessed by a twin decline system (currently
at an advanced stage of development) from the
north-east wall of the current Wassa open pit.
The system will enable efficient ventilation
during the early stages of the underground life
and removes the requirement for a raisebore
GSR goes underground
in Ghana
A Cat 50-t truck at Wassa.
The mining fleet deployed
on the project includes
Cat LHDs and haul trucks
and Sandvik jumbos and
drill rigs.
Golden Star Resources (GSR), listed on the TSX, NYSE AMEX and the Ghana Stock Exchange (GSE),
reports it is progressing well with the development of two high-grade, low cost underground mines at
its Wassa and Prestea properties in western Ghana. Wassa Underground is the more advanced project
and is due to deliver its first gold production within the next few weeks while Prestea Underground
should be in production by mid-2017. The estimated pre-production capex for the two projects is
US$39 million for Wassa and US$63 million for Prestea.