NARROW VEIN & LOW-PROFILE MINING
improved labour efficiencies, Anglo Platinum said.
The machines have sensors and cameras
allowing production data to be monitored in real
time from the surface. Ultimately, it will be
possible to also operate the units from surface.
In Australia, a DOK-ING XLP dozer is also set for
a trial at a small underground gold mine in the
Goldfields region of Western Australia. The mine in
question, which uses the long hole open stoping
method, has been unable to recover ore from a flat
dipping area of the orebody.
Facilitated through DOK-ING’s Australia
distributor, Mine Tech Australia, the trial could
take place over a one- to two-month-period and
involve an XLP dozer recovering gold the mine
owner had previously written off, Brendan Tritton,
Director – Operations Manager at Mine Tech
Australia, told IM.
“The client has a couple of areas they are
looking to utilise the DOK-ING XLP dozer in,” he
said. “It could help reclaim lost ore that has been
left behind due to it being a horizontal flat-dipping
orebody that doesn’t suit their standard operating
procedure.”
The trial, which will involve a diesel-powered
unit, was yet to start when IM spoke with Tritton
in June, but he said the Mine Tech Australia team
were now well equipped to handle the teleremote
unit having recently completed advanced training
to meet the client’s needs.
He is excited about the prospects for these
machines in Australia, saying the incorporation of
battery technology will open the number of
applications.
“It will be a real turning point for this
equipment in Australia,” he said. “With smaller
orebodies, ventilation costs are huge. If you can
operate off a smaller size fan through using
battery-electric equipment, it can dramatically
change the mine economics.”
The unconventional approach
As OEMs continue to come up with new designs
for narrow-vein mines, others in the space are
looking to turn conventions on their head.
Bauer Technologies is a company usually
associated with civil engineering, yet the trench
cutting technology it initially developed for this
industry appears to have applications in various
bulk sampling and mining contexts.
Among these is narrow-vein mining, with the
company’s Vertical Cutter Mining System having
previously been tested on dykes and veins below
surface at Koidu Limited’s kimberlite mining
leases in Sierra Leone.
Looking to mine dykes for kimberlites to a
greater depth, Koidu and Bauer agreed to trial the
BC 33 cutter at the mine in 2010. The cutter width
chosen was 800 mm, based on Koidu’s
assumption of a dyke width of between 800 and
1,000 mm.
While the test appeared to be a success, Bauer
has not trialled this system in a narrow-vein
mining context since. Still, it sees plenty of
prospects ahead.
“We see a lot of opportunities not only in
kimberlites, but also in other commodities like
gold, metallurgical coal and uranium, as well as
for deep sea SMS deposits,” the company told IM.
To try and entice the industry into testing this
technology, Bauer is working on extending the
application of the standard cutter system towards
the mining of much harder rocks at much higher
production rates, it said.
“Secondly, based on the very positive
experience on our FalCon kimberlite bulk sampling
project in Canada, now our system, proven in the
mining industry, can reach a depth of 250 m from
a working elevation,” the company said.
“Both systems are key elements to make the
cutter system more attractive to the mining
industry.”
Anaconda Mining spin off Novamera is also
plotting its entry into the underground narrowvein
mining market from surface.
The company thinks a combination of drilling
and imaging techniques already proven in the oil
& gas industry could provide the technical and
economical means to mine steeply dipping
narrow-vein orebodies.
The process, Sustainable Mining by Drilling
(SMD), is divided into two campaigns: drilling the
pilot holes and accurately
mapping the vein, then
enlarging the pilot holes
to predetermined sizes to
recover the ore. Using an
inclined mast drilling rig,
an inclined pilot hole is
drilled along the centre
line of the vein
(equidistant between the
hangingwall/footwall)
with a directional drilling
system.
Steering the pilot holes
live with a survey tool will
determine the current
orientation and refine the
3D model of the vein used
to plan the pilot hole
enlargement, the
company says. Once the
pilot has been drilled, a
large hole-opener can be
used to open the hole’s
trajectory up to 2 m in a
single pass.
Novamera President
and CEO, Dustin Angelo,
told IM that the company
had plenty of work to
carry out prior to the planned field tests of SMD in
early-2022.
This includes developing a prototype near bore
hole imaging tool (NBIT) to use with its ground
penetrating radar unit.
“We'll be field testing the NBIT tool around the
August 2020 timeframe,” Angelo said. “We will
also continue to refine the tools we use to filter
the data and produce 3D images.”
With respect to the hole opening and
excavation part of the SMD system, the company
will be working on optimising penetration rates,
carrying out testing on fatigue and cutter wear
rates, and hole stability tests, he said.
“We are evaluating the possibility of doing a
small field trial of the pile top drill rig,” Angelo
added.
The company is also identifying and reviewing
additional off-the-shelf, already commercialised
equipment and components that can be used in
the SMD system development to mitigate any
perceived technology risk.
He concluded: “Based on our current plans, we
are targeting to have the full prototype SMD
system ready by the end of June 2021. We would,
then, begin validation testing and make
subsequent adjustments throughout the
remainder of 2021 with the intention to begin to
mobilise in early 2022 for the full scale field trial
at Anaconda Mining's mine site in Newfoundland
in late spring/summer 2022.” IM
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JULY/AUGUST 2020 | International Mining 63