WINNING
The biggest challenge in quarrying granite is what lies behind the wall face.
saws loosen the rock by creating 90cm holes;
the conventional method is then to split the
bench by using a combination of explosives,
drilling, and expansive mortar, with the
non-conventional method involving cutting
the slab with circular saws. It depends on
the geology.”
Finstone is increasingly turning to
percussion rigs on its quarries: it currently
has five, of which two are in use at
Springbok, and plans to acquire a further
three rigs during this year. Finstone COO
Ian Ashmole explains that these deliver the
same production as 20 handheld
jackhammers, being more efficient and less
labour intensive. Mechanisation is part of
the group’s initiative to drive down costs
and restore its competitiveness in the
export market.
Although Springbok was using circular
saws on the day of the Quarry Southern
Africa visit, Ashmole explains that this is the
exception, as circular saws only suit wide
benches, which is not the case at Springbok.
They were in use only to level out the size of
its benches in one location.
18_QUARRY SA| MARCH/APRIL 2019
“The saws loosen the benches for the drill
rig operators to take out the 10m blocks. We
try to keep all our benches within this 10m
height range. This helps reduce waste: a block
cannot be higher than 2m, or it is too big. If
the bench were to be 11m, then one metre
would be wasted. A defect is one thing, but we
don’t want to waste quality material,” says Smit.
“We use the diamond wire saw and the
circular saws to cut all the sides of the block
loose; thereafter we use the drill rig to drill
holes and the percussion rigs to intercept
holes for the circular saws to get all the wires
in and to loosen the benches for production.
Then it gets hauled by an Iveco truck to the
production plant where it is cut and readied
for shipping.”
The quarry uses all its own workers
for the drilling and blasting, with no
contractors employed for this function. It
has 58 employees at the moment. The only
contracting is for the transportation of
material from the quarry to port.
Smit describes the break-even target as
20m 3 production a head — only above that
level does the mine start to make a profit. It
is easier at a large quarry such as Springbok
to make up days lost to weather or other
reasons. “But on a small quarry, a day lost
to weather or a day without electricity is lost
production.”
One way of making up lost production at
Springbok is to work the cleanest bench with
the highest recovery to get faster production.
This is precisely where it was working at the
time of the site visit.
Making up time makes for demanding
schedules: “A few years ago, we were
compelled by the DMR (Department of
Mineral Resources) to employ numbers of
women in the pit. We put them on the saws,
on the jackhammers, on the liners and the
dumpers — but it didn’t work over a period
of three cycles. They physically could not
perform the work. It was the same experience
throughout the whole group — we have
only one of the ladies left working in the
quarry [there are women in other jobs]. We
documented everything and presented it to
the DMR.”
There is a large processing plant on the site,
but Smit says that as part of a restructure,
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