WINNING
NPC Sterkspruit Aggregate supplies a wide
variety of local clients such as block yards,
asphalt plants, hardware shops and precast
concrete manufacturers. Its business depends
to a large degree on local road projects in the
surrounding area.
material as possible. Thereafter the drilling
contractors come in and they will drill the
bench according to pattern and depths
we have agreed upon. They then come
and charge up the drill holes and set off
the blast. The excavators and dumpers
remove all the blasted material to the
crushing plant where it’s broken down to
the different aggregate sizes we require,”
explains Mandass.
For the high walls, the company’s code
of practice dictates its walls be kept to a
maximum height of 15m and minimum
bench width of 20m. “Adhering to the code
of practice is a challenge due to nature of
our deposit,” says Mandass.
From this process, Sterkspruit produces
aggregates in the form of concrete stone
26.5mm down to 6.7 mm; crusher dust; as
well as of base course from G1 to G7. The
tonnage produced at the quarry is closely
aligned to sales rather than actual capacity –
the higher the sales, the higher the tonnage
processed. “We supply a wide variety of
local clients such as block yards, asphalt
plants, hardware shops and precast concrete
manufacturers. We also depend on to quite
a large extent on local road projects in the
surrounding area.”
Little of the product is beneficiated at
the plant, with the one exception being
the washing of the crusher sand. “The
one advantage of the product from the
NPC Sterkspruit Aggregate quarry is the
beautiful colour of the quartzite,” says Avin.
Operations on the quarry are highly
efficient, with one load cycle of aggregate
“If you were to time it I believe would take
about 15 minutes from the time rock it was
tipped into the primary crusher hopper
until it ends up as product.”
Quartzite requires rugged
equipment
Crushers and screens are supplied by a
combination of mainly Osborne and Metso,
all long established suppliers in
the industry.
“The Dezzi equipment we have was
“We monitor and benchmark our electricity usage
against our sister quarries in South Africa and elsewhere
in the world, so that if any of them are controlling their
electricity consumption better than us then we can learn
from and follow their example.”
Quartzite’s soundness and abrasion resistance are superior to most other materials, making it a
superior construction material.
www.quarryonline.co.za
QUARRY SA | NOVEMBER/DECEMBER 2018_21