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MODERN MINING
December 2016
MINING News
Namibian copper miner Weatherly
International, listed on AIM, reports that its
Tschudi project near Tsumeb in northern
Namibia re-attained its nameplate pro-
duction rate during October, two months
earlier than forecast.
In October the company repeated its
Tschudi guidance from July that name-
plate production rates of 1 417 tonnes
per month (tpm) would be re-attained by
December 2016, following the reduced
production in the June and September
2016 quarters due to excessive groundwa-
ter inflow to the pit.
Weatherly has also updated on its
potential Tschudi expansion to 20 kt/a,
which it first announced in December 2015
when it said the expansion would require
expenditure of US$1,2 million. Subsequent
optimisation of the operating parameters
used within the solvent extraction and
electro-winning plants has now reduced
this capital estimate to US$0,2 million.
The company says the focus for the
expansion opportunity evaluation has now
shifted to evaluating mining, pad devel-
opment, stacking, and leach scheduling
paths to sustain such a potential expan-
sion and quantifying potential operating
cost savings from the expansion.
Regarding its Otjihase and Matchless
underground mines in the Windhoek area,
both in care and maintenance, Weatherly
says the mineral resources at the mines
plus the installed processing plant capac-
ity present a valuable opportunity for the
company. Success will be dependent on
achieving higher production rates and
lower unit costs than were achieved dur-
ing the period from 2011 to 2015. This will
be critically dependent on safer and more
productive undergroundmining execution
capability and operator skills development
in this area is the critical requirement to
unlock the opportunity.
The company notes that the geol-
ogy and processing characteristics of the
Otjihase and Matchless orebodies are
well understood and offtake agreements
remain in place for the high-quality con-
centrate which can be produced. While
some further geological resource devel-
opment work may be required over time,
for example to upgrade the historical esti-
mate at Old Matchless to a JORC mineral
resource estimate and to upgrade and
extend the Matchless Western Extension
resource estimate down plunge, the criti-
cal path to implementing a sustainable
restart of operations lies with underground
mining skills development.
Weatherly says it has identifed a
potential opportunity to commence a
skills development programme in a man-
Tschudi gets back to nameplate capacity
The Tschudi open-pit, heap leach, SX-EW operation near Tsumeb in northern Namibia. Its current capacity is 17 kt/a of LME Grade A copper cathode (photo:
Weatherly International).
ner which could be incrementally cash
generative at current spot prices within
six months of commencement, partially
offsetting current care and maintenance
costs being incurred at the sites. Ultimately
it is envisaged that a period of up to two
years may be required to develop the
requisite improvements in underground
mining operator skills and to train suffi-
cient Namibians to the best international
standard and fully realise the potential of
Otjihase and Matchless.
Under the proposal, small scale min-
ing and campaign processing would be
conducted by a small team in the first
scheduled primary mining area at Otjihase.
All of this mining would be conducted in
ore and the programme would commence
with the establishment of productive and
safe primary mining systems.
The current strategic goal envisaged for
such a restart would be safe and sustainable
production from the Otjihase concentra-
tor of 10-12 kt/a of copper in concentrate
at C1 unit costs of below US$2/lb. Due to
the large amount of underground access
infrastructure in place plus the fact that the
Otjihase concentrator is well maintained
and capable of treating up to 800 kt/a of
ore, the capital expenditure required to
deliver such an outcome is expected to be
very low, and would likely rank as one of
the lowest capital intensity copper produc-
tion opportunities in the world.