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MODERN MINING
January 2016
Top projects
COPPER
H
aving gained experience from its
initial transition to underground
mining nearly 20 years ago,
Palabora is taking advantage of
similar conditions and grades
to forge a 33 500 tonne per day (t/d) operation
from a production level at 1 650 m below sur-
face. The aim is produce ore by late 2017.
Plans to mine underneath Africa’s widest
open pit – some 2 000 m in diameter at sur-
face and over 800 m deep – were first put into
action in 1997, when shaft construction began
on the Lift I project at 1 200 m deep. First ore
was drawn from Lift I in 2001, well-timed to
overlap with the open pit’s closure in 2002,
although it took until May 2005 to reach target
production of 30 000 t/d.
Mainly due to the competence of the rock
mass – leading to insufficient fragmentation
of blasted ore and later the subsidence of the
pit’s north-west wall – the lifespan of Lift I was
shorter than expected, and a base-case pre-fea-
sibility study was therefore conducted for Lift
II and approved in June 2012.
A bankable feasibility study followed in May
2014, providing a positive business case to pro-
ceed, based on a grade of 0,64 per cent copper
and an orebody very similar in size, shape and
grade to the one exploited by Lift I.
“Key to the confidence underlying the Lift
II project has been the geological certainty
around the deposit,” said Nick Fouche, General
Manager for Palabora’s Growth Division,
responsible for Lift II. “We had the benefit of
all the initial drilling results for the opencast
pit, followed by about 26 000 m of drilling for
Lift I, and then another extensive programme
totalling 72 000 m of core drilling data, more
recently for Lift II.”
This, he said, gave them a better understand-
ing of how the cave would develop and how
the ore grades would transfer to the produc-
tion level, giving more certainty about what ore
values would report to the drawbells at every
stage. By the time the go-ahead for the project
was given in November 2014, shareholders had
allowed about R2 billion to be invested in the
Yet another lease on life
for
Celebrating a new record
at Palabora. The machine
in the background is
Master Drilling’s 120-ton
RD8 raise borer. The brand
newmachine – the largest
manufactured by Master
Drilling to date and one of
the biggest in the world – is
being used to bore two
6,1 m diameter ventilation
shafts for the Lift II project to
a depth 1,2 km.
Taking over where its Lift I project left off, Palabora
Copper’s R9 billion Lift II expansion is giving the well-
known South African mine another two decades of life
– by developing one of the world’s deepest and largest
block-cave operations.
Modern Mining
contributor Paul
Crankshaw reports on the project.