platinum
31
07.13
The No 16 Shaft complex. Once in full production, it will produce 185 000 ounces of platinum per year.
economic climate in the early 90s was not good. No 15
Shaft was stopped and No 16 Shaft was left on paper.
At this time Impala went through a major restructur-
ing and No 16 Shaft went through many options.
“These options and trade-off studies carried on
over the next 10 years and eventually – in 2002 – a
final option was tabled. No 16 Shaft was a large com-
plex, producing over 500 kt/month. It had 10 levels,
twin production shafts and four other vent/fridge
shafts. There were trackless and hybrid mining sec-
tions, as well as conventional mining sections, and it
was located over the road near to where No 17 Shaft
is today. It was a very exciting proposition and looked
like it held promise to go forward.
“However, there was also a substantial capital
outlay and the NPV financial model did not give a
positive return,” Bremner continued. “We could not
make it work. All stakeholders then requested that
due diligence be carried out to identify issues and
opportunities.”
Bremner said the result of the due diligence was
that Impala reverted to its “traditional model” and
what it did best on other shafts. “The first thing we
did was to revert to the traditional 2 km dip and 4 km
strike mining block with six levels,” he said. “This
moved No 16 Shaft to the current block. We then
derived the resource to set the initial criteria for the
project at a very high level to determine if we had a
viable opportunity or not.”
The Feasibility Study was started in mid-2003 and,
according to Bremner, this was when the challenges
started. “We had no geotechnical evaluation holes for
the shafts (essential to determine the structural integ-
rity amongst others) and we also had to locate them in
the mining block,” he said. “The old ones were in the
block across the road. So they were drilled. Also we
had low resolution 3D seismics of the block and new
high resolution 3D seismics were also carried out to
improve the confidence levels and reduce the risks of
the unknown.
“As the information came in, we had to make
changes. First, the dip of the reef changed in the up-
per levels and we had to add a level. This was after
we had done a lot of work on the mine design. Then
the Hex River Fault hit us and we had to address the
challenges – including water – associated with this
geological anomaly.
“We identified the opportunity of developing a
RAW from No 1 Shaft to utilise spare vent capacity
and for a second outlet to reduce risk and improve
safety. There were others and eventually in 2004 we
had a project that worked on paper and we secured
Board approval in 2004 with lots of lobbying and pre-
sentations.”
Recounting the early months of the project, Brem-
ner said site establishment took place in September
2004 and that soon thereafter holes being drilled for
geotech work hit water a few metres below surface.
This resulted in the shaft layout being changed, with
the main shaft moving to the vent shaft position and
the vent shaft moving to a new location.
Concluding his talk, Bremner listed some of the
highlights of the project including the slide of the con-
crete headgear in just 33 days – which he described
as “fantastic to witness” – and the start of sinking on
both shafts ahead of schedule. He also noted that the
project team had delivered the project on time de-
spite many heated – but always constructive – meet-
ings and “much planning and replanning”.
The final word on No 16 Shaft should probably go
to Implats’ CEO, Terence Goodlace. In a statement
released to coincide with the beneficial handover,
he said the project team could be extremely proud
of its safety performance and project milestone
achievements. “This team has achieved more than
two million fatality free shifts and the shaft has been
equipped and commissioned within planned param-
eters and budget,” he said. “Preparations for mining
operations will start immediately and first stoping is
expected to start in the September 2013 quarter. The
new shaft complex ensures that Implats remains in
an excellent position to benefit from the long term
PGM market fundamentals, specifically in an indus-
try in which the supply side is being constrained by
a lack of investment. This will also secure jobs for
6 500 people that are currently employed at the older
generation Rustenburg shafts.”
Photos: Arthur Tassell
