business
view, aiding in the mapping of geological
structures over large surface areas. These
drones can, if fitted with the correct
camera equipment, capture high-resolution
overlapping stereo-photogrammetric photos,
which are used to generate aerial maps and
3-D models of the landscape.
Steenkamp explains that on the
environmental side, drones can be used for
erosion detection and inundation tracking,
as well as for the long-term monitoring
and tracking of changes in vegetation, and
the movement of wild animals in protected
and sensitive areas. Drones are also
useful for hydrogeological investigation
activities, including drainage and water
management planning; the mapping of
watersheds, drainage basins and water
flow; and the thermal detection of
groundwater inflows. And in geotechnical
operations, drones can be used for looking
at joint mapping in quarries; monitoring
the surface stability of sidewalls, high
4. Reporting: Drones can be used to
monitor the production process in
open-pit mines and for early detection
of deviations and threats, enabling
mine owners to increase safety and
decrease costs of controlling processes.
Early detection of irregularities and
correct assessment of the open pit
allows for quick response and better
planning, and could also be used to
reduce extraction costs.
According to independent geological
consultant Dr Nicolaas Steenkamp, while
conducting aerial geological surveys was
expensive and time consuming in the past,
the introduction of UAVs with their ability
to fly at low altitude at a slow, controlled
speed along a predetermined flight path
offers many advantages compared with
the piloted vehicles used before. Compared
to commercial satellite photography
or photographs from manned aircraft,
drones provide a stable, 360-degree aerial
Professionals from various industries, including mining, gathered at the Drone Con 2017
conference to hear the latest about the use of drones in industry in South Africa.
Using drones for topographic surveys reduces wear and tear on equipment
while simultaneously improving data collection and turnaround time.
14 _ QUARRY SA | SEPTEMBER 2017
walls and benches; and mapping steep,
inaccessible inclined areas.
He adds that there are significant
potential benefits to using UAVs in opencast
mining operations, including assistance with
short-term planning in the field (open-pit
and dump management, haul route surface
optimisation, and damage assessment and
control) and long-term planning applications
(haul road, dump and pit design, and control
of mining in high-risk void areas). Drones
can also be used to optimise drill-and-blast
operations by providing up-to-date surface
images for blast designs, collecting pre- and
post-blast data, and identifying misfires and
wall damage.
Blasting optimisation
Speaking at the recent Drone Con conference
held at Vodaworld in Midrand, blasting
optimisation manager for AEL Mining
Services, Hennie van Niekerk, explained how
drones can be used to optimise blasting and
analyse fragmentation. “How can drones
assist in getting blasting improvements and
improving efficiencies for a mine? First, you
need a very accurate GPS. Then you need
a high-resolution camera and you need
to know the orientation so that you can
contextualise the information. Once you
have all of this, then the data capturing
starts. And a drone is just a data capturing
device — it’s how you use the data that will
make the difference. You need the correct
software, which needs to provide output
in a useable format that you can use to
improve your efficiency and improve your
mining stream.”
Van Niekerk explained that using
drones to assist in analysing fragmentation
distribution can improve both accuracy and
safety. “At the moment, we are doing it sort
of manually; there’s a guy walking around
with all the loose materials and rocks and it’s
actually very dangerous. But if we get drones
to assist with this and take the pictures, they
know the exact altitude, how far away they
are from the rock, and can triangulate the
size of the rocks based on the pixels of the
camera. Feeding this information into the
appropriate software then gives you your
fragmentation distribution.
“This is particularly important in the
quarry market, where your earthmoving
material is generally a bit smaller than your
big draglines, but you want to move it as
quickly as possible. If your fragmentation is
small and designed for your shovel, you can
get optimal efficiencies from your shovel
and from your earthmoving vehicle — you
can fill them optimally. If you have big
boulders or lots of fines, you decrease the
efficiencies of the material.”