NARROW VEIN & LOW-PROFILE MINING
No-constraints innovation
Dan Gleeson looks at some of the conventional – and
unconventional – ways metals and minerals can be extracted
from narrow vein and low-profile mines
The development of narrow vein and lowprofile
mines has proven to be a major
technology catalyst within the underground
mining industry.
The need to remove people from confined,
unsupported and potentially risky areas
underground led to the introduction of
teleremote, line-of-sight loading: a precursor for
full machine automation.
The difficulties and cost associated with
installing and maintaining fans for adequate
mine ventilation in these compact environments
could also be seen as another contributing factor
to the automation trend. This also had an impact
on the onset of electrical-powered production
and development machines.
And, of course, as more miners looked to
develop and mine narrower and more compact
orebodies in an effort to reduce dilution and cut
operating costs, original equipment
manufacturers (OEMs) were forced to make
equipment that delivers the same performance as
conventional machines within a much smaller
footprint. This is another development the wider
underground mining industry is thankful for.
Engines for the environment
Aramine has ended up specialising in building
equipment tailored to these cramped conditions,
with several machines in its range designed for
narrow-vein applications.
Marc Melkonian, President of the company,
says one of the biggest issues that has plagued
the underground mining industry for decades is
the air pollution that affects worker health.
“To respond to this issue, we have always
equipped our diesel miniLoader ® with an exhaust
purifier,” he told IM.
Aramine’s second step to decarbonise the
environment was developing an electric machine
with a cable – “the battery-powered machine was
already in our mind, but this technology was not
reliable enough at that time and very expensive”,
he explained.
Today, after two years of R&D, the company
has a reliable and competitive battery-powered
product for the narrow-vein mining sector in its
miniLoader L140B.
An optimised and advanced version of the
L120B, the miniLoader L140B can carry a 1.4 t
payload, has a 0.6-0.8 cu.m bucket, and comes
with a length of 5.3 m and width of 1.1 m, making
it suitable for narrow-vein operations.
“Compared to the diesel-powered alternative,
the Aramine miniLoader L140B clearly enhances
the quality of the work environment for the
operators and employees working around the
machine,” Melkonian said.
It is also very quiet when operating and the
battery-drive technology offers not only improved
air quality, but also significant savings on mine
ventilation, he added.
The miniLoader L140B is now operating in mines
in Europe, Russia, and even at high altitudes in
South America, according to Melkonian.
“The true challenge for the users is to change
their habits (to get the most out of the machine),
but our machine reliability and ease of use have
immediately pleased the users,” he said.
“The battery-powered machines offer the
same, or even more breakout force than the
diesel equivalent. As our battery-powered
machines are using an electric transmission, this
allows adjustment of the torque depending on
the mine ground to provide just enough power
and avoid tyre spinning,” he said.
“Plus, Aramine has reduced the maximum
number of components in the hydraulic system to
GHH’s low-profile loaders have excellent
weight distribution, resulting in better loading
characteristics and increased component and
tyre life, according to the company
increase the maintenance intervals to 2,000
hours (apart from daily checks and lubrication).”
While improving the working environment for
miners and reducing the maintenance
requirements are both valuable benefits, any new
electrified machine will have to match up to its
diesel equivalent to find widespread appeal in all
markets.
“The solution is successful because our clients
can keep the same productivity compared to
working with a diesel-powered machine, and
even increase it on some days,” Melkonian said.
The miniLoader L140B has been aided in this
productivity quest by the ability to carry out four
hours of continuous operation without recharging
– enough to muck three to four faces in
one shift. After this point, an on-board charging
system, requiring only 7 kW of power, is plugged
into a wall socket to charge the battery.
For those requiring even more productivity, the
Quick Replacement System (QRS) has been
designed.
This allows the battery in the miniLoader
L140B to be changed in just a few minutes. A
stationary changing bench that can hold up to
three battery packs with a crane to assist and
facilitate the battery replacement has been
designed by Aramine, and the company is also
testing a mobile station to enhance the QRS
flexibility.
Melkonian explained: “Depending on the mine
layout, it (the mobile station) can be useful when
the changing bench can follow to the face to
muck and stay close to the miniLoader to reduce
the running distance.
JULY/AUGUST 2020 | International Mining 55