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MODERN MINING
June 2016
WEST AFRICA
feature
The open pit at Wassa.
Ore from the underground
mine will soon start to
supplement the open-pit
production.
GSR personnel at Prestea. The mine’s infrastructure – operated over 100 years – includes vertical and inclined shafts,
horizontal development, raises and stopes developed along the 9 km of strike length of the gold mineralisation.
metallurgical recovery in fresh ore is currently
93 % and future recovery from the combined
Wassa open-pit and underground operations is
expected to be the same.
Work started in earnest on Wassa Under
ground after completion of the FS and in May
this year GSR reported that the declines had
advanced 1,9 km, with the average rate of
advance achieved being 8,6 m per day dur-
ing the first quarter of 2016 (which was more
than 20 % higher than the development rate
in Q4 2015). GSR is currently predicting that
Wassa will produce between 120 000 and
135 000 ounces of gold this year, with between
20 000 and 25 000 ounces of this total coming
from underground.
Turning to Prestea, this is located south-west
of Wassa near the town of Prestea. Probably
the most famous mine in Ghana after Obuasi,
it started production in the late 19th century
and has reputedly produced 9 million ounces
of gold over its life. It consists of an established
underground mine and adjacent surface depos-
its. It was acquired by GSR in 2002 but placed