NARROW
VEIN
& LOW
PROFILE
MINING
NARROW
VEIN
& LOW
PROFILE
MINING
Anaconda Mining’s goal of finding a technology to economically extract
gold from the Romeo & Juliet deposit at its Point Rousse operation in the
Baie Verte region of Newfoundland, Canada, has gained a global audience
since it was named a finalist at the Goldcorp-backed #DisruptMining
event earlier this year.
The company’s technology-focused subsidiary thinks a combination of
drilling and imaging techniques already proven in the oil & gas industry
will provide the technical and economical means to mine the steeply
dipping narrow vein mineralisation at the deposit.
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, Anaconda said, adding that once the pilot has
been drilled, a large hole-opener can be used to enlarge the hole’s
trajectory up to 2 m in a single pass.
While Anaconda is focused on using SMD to mine its own complex
deposit, as with many innovations in the mining sector, the technology
looks like having global applications.
IM spoke with Dustin Angelo, President and Director of Anaconda
Mining, to find out, among other things, how SMD can: reduce the cost to
extract ore by 50% over conventional underground narrow vein mining
techniques; increase operator safety by locating personnel above ground;
access areas not open to conventional mining; reduce the environmental
footprint of an operation; and bypass the crushing and grinding circuits
by moving the ±2 mm drill cuttings in a slurry direct to the mill.
IM: Anaconda says the technology that has gone into SMD is proven in
other industries: what are these industries?
DA: We’re basically adapting technologies that have been used in the oil
& gas industry for quite some time; directional drilling and sub-surface
imaging. Even though we are dealing with new technology and a new
process, what we’re working with, fundamentally, has been used
elsewhere in other industries. We’re not reinventing the entire wheel;
we’re just adding to that wheel.
We have got patent-pending inventions within SMD related to two key
areas – the drilling and imaging. From the drilling standpoint, one of the
key considerations we need to address is being in ore right from surface.
We have developed some inventions that are added to a pile top drill rig
to be able to get the required torque and thrust immediately from
Anaconda’s Dustin Angelo says the company has developed some
inventions that are added to a pile top drill rig to be able to get the
required torque and thrust immediately from surface to extract ore using
SMD
surface. We have also created a component that enables a drill string to
be more flexible than normal to allow for course change during the hole
opening phase.
In terms of sub-surface imaging, we are looking at ground penetrating
radar (GPR), which is right off the shelf, but we’re adding some surveying
tools to it in order to be able to improve visualisation and more clearly
orient ourselves when steering.
IM: How flexible is that drill string? Are there limitations in terms of angle
and depth?
DA: We’re looking at a 1 degree change every three metres in the work we
are planning to carry out at Romeo & Juliet. And, right now, the depth is
down to about 300 m. What we’re using is RC airlift assist to bring the
cuttings back up, so the technologies that are out there allow us to go to
that depth. Yet, one of the drill manufacturers we are talking to is
experimenting with getting down to 400 m; this is all dependent on the
production environment, according to Tom Sertic,
DOK-ING South Africa General Manager. This trial
should happen during the second half of 2019, standardisation of spare parts (each NRE prime
mover has the same components with the
difference in tool attachments), and streamlined
he added.
“The unique features of the NRE equipment
include the ability to work in stoping widths from training for the operators and maintenance
person, Sertic said.
Sertic concluded: “Manufacturing of the prime
mover machine was completed in South Africa
and skills transfer will continue in the near future
to enable the complete equipment to be made in
0.9-1.7 m, as well as the ability to interchange
the prime mover for dozer and sweeper and
another for drill rig and support rig,” Sertic said.
These features address a lot of the common
issues related to operation and maintenance of
the equipment, he explained.
Such features result in lower capital expense
due to less prime movers and more tools,
44 International Mining | JULY 2019
the country.”
Hybrid miniDriller
Aramine has looked to complete its narrow vein
equipment range with the introduction of the
diesel-electric hybrid miniDriller DM901 HDE drill
rig.
The machine uses the diesel engine for
tramming and electric motor for drilling, while it
can be operated tele-remotely, removing the
operator from potential hazards, Aramine says.
The DM901 HDE has a low centre of gravity for
optimal stability. Despite its narrow width, the
two front stabilisers offer perfect drilling
conditions, according to the company, thus
allowing both face and vertical drilling.
Aramine says the DM901 HDE only requires a
400 V electric connection and a water supply to
operate and is designed with modular elements