NARROW VEIN & LOW-PROFILE MINING
variety of mineral deposits, and thus designs and
cross-sectional areas of underground openings
differ greatly. Usually the most common ones are
narrow-vein mines, which have diameters of about
2 x 2 m to 3 x 3 m.”
The latest addition to the company’s lineup is a
lithium battery LHD LE110, which comes with a
1.25 m width (length 4.9 m, height 1.67 m) and a
tramming capacity of 1 t (featured in more detail in
IM June 2020’s Load and Haul feature).
Narrowing down the drills
Since IM heard from Peru-based Resemin in this
same feature last year, the company has secured
another two orders for its 1.15 m MUKI Bolter
suitable for narrow-vein mining applications, CEO
James Valenzuela said.
Like the organisers and exhibitors of MINExpo
2020, the company has been affected by the
lockdowns and travel restrictions tied to the onset
of COVID-19.
It has been working on electrifying its fleet of
narrow-vein mining equipment for some time and,
prior to the onset of COVID-19, was making
headway with its Troidon 55 battery-powered drill
rig.
Valenzuela told IM that the lockdowns that
came into force in Peru on March 15 stopped
progress on electrifying this single boom front
face rig.
“Now we expect to end construction of the
machine at the end of this month, so a trial will be
planned around mid-July,” he said.
Despite this setback, the company has been
making progress on its other area of technology
focus: automation.
Having previously sold three MUKI LHBP-25
long hole drills equipped with CAN BUS system for
tethered teleremote control to India last year, the
company recently offloaded some small long hole
drill rigs with these capabilities.
Fully autonomous machine requests have been
seen by the company in tenders for projects, but
Valenzuela felt the need to clarify the realities of
deploying such technology underground.
“Digitalisation on drilling rigs is good, but it has
some challenges because more automation
means less confident machines,” he said. “I say
this because electromagnetic sensors are very
vulnerable to the tough environment of
underground mines; they fail very often.”
This makes fully automated drilling, for
example, very hard to carry out. “It is a well
published technology that doesn’t work basically,”
he said. “It is a fact.”
Sandvik Mining and Rock Technology has made
automation leaps in the field of underground
development drilling, yet it has also developed
products specifically for narrow-vein mines and
other confined areas.
Its new 2711 class of drills are simple and safe
to operate, with robust components, and provide
an excellent performance to ownership cost ratio,
according to the company.
Sandvik explained: “Selective mining methods
and small tunnel developments have proved to be
a good way to extract ore economically, and
control the dilution when ore is distributed in
narrow veins typically less than 2-3 m in width.
Sandvik’s narrow size underground drills are thus
designed specifically with the requirements of
drilling narrow vein drifts and that of small tunnels
projects in mind.”
The drills are also equipped with Sandvik’s
Fleet Data Monitoring systems, enabling mines to
improve fleet performance and management, it
says.
The 2711 series consists of three drill types
using a common platform covering different
applications: namely development drilling,
DD2711, rock support bolting, DS2711, and long
hole production drilling, DL2711 and DL2721.
The DD2711 is a compact and flexible single
boom electro-hydraulic jumbo with a minimum
cross section of 2.7 m x 2.7 m. The versatile boom
delivers large coverage and fully-automatic
parallelism for fast and accurate face drilling,
while 20 kW of drilling percussion power is
provided through Sandvik’s HXL5 rock drill, it said.
The rig is designed for underground hard-rock
applications that require high capacity and
reliability in development blast holes ranging from
3.7-4.3 m in length.