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GOLD
22
MODERN MINING
July 2015
D
esigned as a hybrid gravity/
CIL and heap leach operation,
the Namoya mine poured its
first gold in Q4 2014. The prop-
erty lies at the southern end of
the Twangiza-Namoya gold belt in Maniema
Province, 225 km south-west of Bukavu, and
consists of one PE (Exploitation Permit) cover-
ing an area of 174 km
2
. Alluvial gold was first
discovered in the area in 1930 and was mined
between 1931 and 1947. Primary gold was
also discovered during this period and under-
ground mining on the Filon ‘B’ deposit began
in 1947. Formal mining ceased in the 1960s,
only recommencing with Banro’s development
of the present mine.
During wet commissioning of the process
plant last year, it became apparent that the effi-
ciency of the CIL circuit was being hampered
by the quantity of fines content in the ore, as
it exceeded the design capacity. The company
determined that the best solution to the problem
was to acquire an agglomeration drum to run the
mine as an agglomerated heap leach operation
while pursuing options to best utilise the CIL
plant to process the fines material. An agglom-
eration drumwas procured in the fourth quarter
of 2014 and installed in January this year.
In its quarterly report, Banro says that – as
previously reported – a delay in financing
resulted in a need to modify the mine plan to
allow for the pre-stripping of the Kakula reserve
pit. This modification impacted ore availabil-
ity early in the second quarter as the mine fleet
focused on waste removal in order to allow for
increased access to mining faces when the first
additions to the mobile fleet were commissioned
in late May. This contributed to a decrease in the
stacking level in April to 57 211 tonnes, which
subsequently increased to 130 974 tonnes in
May and 142 082 tonnes in June.
The significant decrease in stacking levels
fromMarch’s 103 163 tonnes to the much lower
April figure was also driven by the adverse
impact of unseasonably high rains which inter-
rupted supply routes and the ability to deliver
procured materials and supplies.
The availability of ore from mining activi-
ties and the available medium grade stockpile
material resulted in the stacking of ore with an
average grade of 1,52 g/t Au.
According to Banro, Namoya management is
Namoya
continues ramp-up
to
commercial
production
The processing plant at the
Namoya site.
Reporting on its activities in the second quarter, Canada’s
Banro Corporation says that its new Namoya gold mine
in the DRC continued to ramp up toward commercial
production levels, achieving stacking levels greater than
140 000 tonnes of agglomerated ore in June.