Mining in focus
At the end of the long line of grasshopper conveyors, a transverse
conveyor is installed, normally at an angle of 90 degrees. The transverse
conveyor, in turn, feeds into a stacker feed conveyor.
thoroughly with the ore fines, which
ultimately makes the process more
efficient.
“The agglomeration drum is the start
of the heap leach stacking process,
which ends at the leaching pad,” says
Theo Winterbach, mechanical and
materials handling manager at Senet.
From the agglomeration drum, the
material is transferred via an intricate
conveyor system to the heap leach pad.
“The heap leach pad covers a large area
and the product has to reach the entire
pad. The system thus requires multiple
conveyors to transfer the material to
the furthest point of the pad,” says
Winterbach. The agglomerate should
be transferred as smoothly as possible,
as it is important to keep it intact. One
benefit of having multiple and mobile
equipment is that a company will not
have to lay out all the capital in the
beginning. Once the team has decided
where the pad will be located, they can
acquire only the necessary equipment
until production starts ramping up.
“The added advantage is that the mobile
equipment allows for a certain amount
of flexibility; therefore, the entire
system can be moved to ensure that
the conveyors feed the stacker at the
end of the chain,”
says Winterbach.
A typical heap is
between eight and
10 metres high.
The normal flow of
material is from the
agglomeration drum
to the grasshoppers
and then to the
linear index
conveyor, which
delivers it to the
stacker machine.
Stacking
the heap
The linear index
and stacker machine
need to move
backwards as the
stockpile is stacked
in preparation for
the leaching. At
A stacker feeder adding agglomerate to the heap
times (depending
where it will be further leached.
on the size of the
heap leach pad),
the entire set of machines has to be
the entire system needs to be adjusted,
fully retracted and repositioned to a
front-end loaders or other applicable
new position on the heap leach pad
equipment can be used to move the
before the process is repeated. When
equipment, as most of the equipment,