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MODERN MINING
January 2016
DIAMONDS
Top projects
The portal of the decline.
Ultimately the decline will
have a length of 7 km.
modification and expansion of the plant will be
required but the capex involved is minimal.”
The underground resource will be mined by
means of the Sub Level Caving (SLC) mining
method in the case of the bigger K01 orebody
with a modified SLC system being used for
K02. The K01 cave will produce 4 Mt/a and
the K02 cave 1,9 Mt/a. “The mining methods
are conventional and well proven, so there’s no
pioneering involved,” says Kühn. “What could,
however, be unusual is the possible use of an
automated trucking loop on the lines of what De
Beers put in at the Finsch mine in the Northern
Cape roughly ten years ago when it owned the
operation. We’re already in preliminary dis-
cussions with a couple of the OEMs on this,
although it must be stressed that at this stage
the use of driverless trucks is no more than a
possibility.” He adds that semi-automated drill-
ing is also under consideration.
While a project the size of the VUP will
typically have many different contractors, sub-
contractors and suppliers involved, Murray
& Roberts Cementation is handling the lion’s
share of the work. “Essentially, they’re respon-
sible for delivering the project to De Beers in
terms of the shafts and underground infrastruc-
ture required,” Kühn says.
Elaborating, he notes that Murray & Roberts
Cementation is responsible for the two vertical
shafts the project requires, both 7 m in diameter
and 1 080 m deep, one a production shaft and
the other a service shaft, as well as a decline for
trackless equipment which will ultimately be
7 km long and provide access to 900 m below
surface. In addition, the company will under-
take horizontal tunnel development to access
and establish the two caves and provide associ-
ated infrastructure, including two large crusher
chambers near shaft bottom.
According to Graham Chamberlain, Project
Executive with Murray & Roberts Cementation,
the VUP also marks a watershed inasmuch as
it is the first project where the Canadian shaft-
sinking methodology is being adopted in its
entirety.
“We have deployed aspects of the system on
some of our other current or recent projects but
the VUP will see it being used from start to fin-
ish in a systematic manner,” he says. “The main
motivation for adopting the method is its inher-
ent safety as all activities in the shaft-sinking
cycle now occur sequentially. At no point do
you have personnel working simultaneously
at different levels within the shaft – as you do
with conventional techniques – with all the
safety risks that this brings and there are fewer
people working in the shaft barrel at any one
time. Teams are multi-skilled and perform all
required tasks. This compares to the old sys-
tem where you had one crew to drill, another to
lash, a third to support and so on. Now we use
a single ‘super-crew’.
“To develop the necessary skills here in
South Africa, we’ve built shaft mock-ups
at our Bentley Park training academy near
Carletonville on the West Rand where trainees
are given total exposure to both the techniques
and equipment – and, importantly, the ‘mind-
set’ – required to implement the Canadian