WINNING
A front-end loader in action loading a truck
for delivery to the processing plant.
“A big cost on our quarry is the wire saws,
because if that gets stuck you cannot get it
out easily. The 100m mass of mountain above
it creates massive pressure which closes the
hole made by the saw blade. All that weight
lies on that wire — costing R100 000 on
average for 75m of diamond wire,” says Smit.
Bearing in mind the cost, another one of the
challenges facing the operation is theft of
diamond wire, but equally of other drill
parts. They are sold to other mines (though
only another granite mine can buy it).
“Historically, we just left it lying around at
knock-off time. Now we have to pack up
everything — all the equipment, wire,
1 000W electrical cables (which thieves just
cut off and steal) and lock it away. This now
consumes an hour and a half of production
time a day. We sometimes get mines calling
us to report someone selling our equipment.
Where we can figure out how it gets stolen,
we have opened criminal cases, sometimes
against our own employees.”
20_QUARRY SA| MARCH/APRIL 2019
During the last quarter of 2018, the quarry
lost 10 days of production due to the theft of
Eskom power line cables.
“Another challenge for the workers on the
benches is the weather: rainy days, harsh sun,
and wind. We have had to develop new codes
of practice (COP) for lightning and rain.
Granite is a conductor of electricity and work
has to stop when there’s heavy rain (due to
slip hazard), and especially thunder and
lightning. We budget to lose three to four
days a month to weather, except winter, and
have lost up to a week at one time. “We are
working at full capacity, so it is not always
possible to make up the days — though we
try wherever possible.”
A quarry manager hopes for light rain to
dampen the dust — but equally hopes it
doesn’t rain so hard as to stop operations.
One 20 000ℓ water truck and another 8 000ℓ
truck dampens the road network every day to
reduce dust, an issue which is more of a
challenge in summer than in winter.
The pit bottom is full of water — a valuable
source of water for dampening the roads
providing 132 000ℓ/day for one water truck
(each truck fills up about four times a day).
The rest of the operations — plant and
offices — use about 40 000ℓ/day of water
from a borehole, and most of this is recycled,
as a filtration and recycling system was
installed at the processing plant.
“We put the graders on the road network
to keep it neat and tidy, which assists greatly
with the maintenance of the loader trucks. In
the past, tyres were cut up like a knife
through butter due to the hard nature of the
granite rock — just a small piece could cut a
R90 000 tyre. Once it is cut, it can’t be fixed
because of the weight of the machine and the
weight it has to carry. We did a risk
assessment and put in place a COP for all
operators coming into a pit with lots of
stones lying around — to first clean the area
with the excavator. Then we throw gravel
down so the trucks are not driving on the
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