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June 2015
MODERN MINING
51
MINING IN AFRICA
feature
I
n March 2014 Resolute released results
from a PFS for a proposed underground
operation at the Syama project. The
study – completed by independent ex-
perts Snowden Mining Industry Consul-
tants – identified an opportunity to migrate to
a long-term, underground mining operation by
exploiting the extensive mineral resource be-
neath the open pit.
During 2014 the company completed a
13 600 m drilling programme to infill and
extend the underground resource. The results
of this drilling were reported throughout the
year and were highlighted by many broad
high-grade intercepts.
In March 2015 Resolute announced that ore
contained within the Stage 2 open-pit mine
plan was best extracted from underground, pro-
viding greater return on capital and a smoother
cash flow profile. It was subsequently con-
cluded that a revised Underground PFS would
incorporate the Stage 2 open-pit resource, as
well as the remodelled deeper resources from
the highly successful drilling programme,
to determine the operational and financial
improvements compared to the earlier study.
Summary of revised PFS analysis
Through geotechnical analysis and investiga-
tion of various underground mining methods,
Snowden determined that the orebody footprint
was sufficiently large for a caving operation to
be developed and selected traditional SLC (Sub
Level Caving) as the preferred mining method
for the following reasons:
The orebody geometry and geotechnical con-
ditions are suited to SLC.
SLC is a highly mechanised mining method,
well-understood and used in many locations
around the world; it can deliver the required
production rate to replace open-pit produc-
tion (about 2 Mt/a) at an acceptable cost.
The subsidence zone will not impact on or
affect critical infrastructure.
Geotechnical conditions are unfavourable for
more traditional open-stoping methods, mak-
ing them lower production rate and higher
cost options.
Resolute successfully uses a similar method
at its Mt Wright operations in Ravenswood,
Queensland, Australia.
The mine design parameters have been based
on Australian experience including Mt Wright
and other typical Australian SLC operations.
Specific mine design parameters may change as
more data and information becomes available
through the Definitive Feasibility Study (DFS)
Revised PFS
delivers boost for
underground mining at
Syama
Syama cross-section displaying decline and level development.
Australia’s Resolute Mining, listed
on the ASX, reports that the results
from an independent revision of
the Underground Pre-Feasibility
Study (PFS) at its Syama gold mine
in Mali confirm that an early move
to underground mining in 2016 will
produce robust economics with
operations at strong cash margins.
The updated study also delivers a
significant increase in underground
ore reserves, incorporating recent high
grade results from diamond drilling
conducted over 2014, including the
previous Stage 2 open-pit resource.