ON THE GROUND
Resembling something akin to an apocalyptic
movie, dust swirls in on the mine.
process designed by Osborn for
efficient crushing and screening
to minimise dust emissions in the
production of calcite and lime,
Shozi points out.
“We have a modular 3042 jaw
plant feeding into a modular 2340
jaw plant, then over modular 6
× 20 triple deck screen, splitting
the product. The primary reason
for the two-stage jaw crushing
process is to minimise the
generation of fines (-10mm), the
material of which cannot be used
in the next stage and is potentially
a waste product,” he adds.
The extraction process
is revolutionary in that a
conventional crushing plant would
be a jaw and cone configuration
to crush down to a -80mm
product from a run of mine of
600mm. The crushing plant
produces 150 tonnes an hour.
“Using modern mining
methods, the mine uses the
latest advances in sorting
technology, which is the IMS
Engineering range, thereby
sorting material to suit client
needs,” he says.
“On the sorting side of the
business, we sort in terms of two
characteristics — chemistry and
colour — and the main equipment
is the sorter itself. It is equipped
with three cameras, including
an infrared camera and a laser
to separate out the impurities
from the pure stone. The sorter
currently produces 50 tonnes an
hour — though we are about to
double it up with a second sorter
on the side,” he highlights.
The sand plant produces 70
tonnes an hour. The impactor with
the hammer mill reduces 80mm
We’re moving rock all the time, and dust is not
friendly to equipment — so regular service and
inspection is necessary.”
stone down to fine sand, where
the finest product is as low as
50-micron, 250-micron and as
much as 1.4, which is the biggest
of the sand plant, Shozi explains.
Osborn also supplied the
mine’s next stage with its
imported high-frequency screens,
to cut at -2+1,2mm; -1,2+0,8mm;
-0,8+0,4mm; and -0,4+0,075mm.
Moving the material is solved
with a range of vehicles, Shozi
explains. “We drill and blast and
then we haul the material using
dumper trucks and excavators,
and front-end loaders at the
plant.”
Rossmin has selected to use
local equipment manufacturer
Dezzi Equipment to undertake
haulage on the mine, supplying
three front-end loaders. “Two are
used for sorting and one is used
mainly for customer loading. The
three dumper trucks are deployed
to feed the crusher,” he adds.
“There were three reasons
why we chose Dezzi,” he
says and points out that as
a local manufacturer, the
factory employs staff from the
community “benefitting our local
community”, he says. Also, owing
to proximity, the OEM is able to
respond timeously to support the
fleet on the mine with servicing
and maintenance requirements,
ensuring maximised productivity
while minimising downtime.
Dezzi also visits for weekly
checks on the vehicles to prevent
out-of-maintenance issues
and greasing of the machines,
thereby conducting preventative
maintenance. In an environment
where there is significant
dust generated, this is a key
factor in the OEM’s after-sales
commitment.
“This is useful,” says Shozi,
“because dust is our businesses!
We’re moving rock all the time,
and dust is not friendly to
equipment — so regular service
and inspection is necessary.”
OCTOBER 2018
15