UNDERGROUND RAIL
One of five 20 t trolley locos at Sierra Metals'
Yauricocha silver-lead-zinc-copper-gold mine,
supplied by Clayton Equipment between 2007
and 2012
Despite rail in underground mining
conjuring up images of men or ponies
hauling heavy ore cars, the reality is that
rail is very much a part of today’s mining industry,
being integral to operations especially in
countries such as South Africa, Peru, Canada,
Russia, Indonesia and China but even in Europe
in operations like LKAB’s Kiruna in Sweden. This
includes both long established set-ups in existing
mines but also completely new mines being
designed around rail. The fact is that where a
mine has a dedicated haulage level and a well
designed network of ore passes, in terms of
capacity and reliability rail still wins out over
trackless mobile equipment. Plus given its nature
it is much easier to go fully autonomous, while
hybrid or battery solutions are much easier to
work with. Already several major mines are in the
process of installing large rail networks based on
the latest lithium-ion battery technology, while in
South Africa, Anglo American Platinum has a
liquid organic hydrogen carrier (LOHC)
technology production test trial phase at the
moment. The fuel cell unit is manufactured by
Hydrogetics and Anglo itself.
The mining rail industry goes hand in hand
with the tunnelling rail business with most OEMs
involved in both, but as will be outlined later in
comments from key players, the markets are
actually very different. Though there are
examples where the two cross over, a classic one
being the new Woodsmith polyhalite mining
project in the UK, which was formerly Sirius
Minerals now acquired by Anglo American. It
Maximum
traction
Paul Moore spoke to all the major players in underground rail
for mining, a fascinating market that still holds its own in the
right context and application for sheer reliability and capacity
as well as being amenable to the latest technologies from
lithium batteries to automation
includes a locomotive supplied by Diepholz,
Germany-based tunnelling loco specialist
Schoema to work in a 13 km section of the 37 km
long tunnel that will connect the mine at
Sneatonthorpe near Whitby in North Yorkshire
with the Wilton International complex on
Teesside. The tunnel in which the loco will work
has a maximum gradient of 3.5% with the loco
towing capacity being 110 t.
NMT's and Schalke’s next levels
North Bay, Ontario, Canada-based Nordic
Minesteel Technologies Inc and subsidiary
Schalke Locomotives GmbH in Gelsenkirchen,
Germany continue to occupy an important place
in the underground mining rail sector across all
size classes and levels of complexity including
the latest automation
systems and hybrid or
full battery technology
including Schalke’s
modular ModuTrac
locomotive which can be
easily converted from
diesel to battery
operation in less than
one hour. When
equipped with an
additional pantograph,
the locomotive can also
be operated as a multimode
unit.
Looking at some of NMT’s ongoing flagship
projects, they include the fully autonomous
NMT/Schalke continuous haulage system on
LKAB’s Kiruna mine level (1,365 m) which handles
some 30 Mt/y of iron ore and has been running
for almost ten years now. This is likely to be just
the latest chapter in this development, with LKAB
looking at more orebodies at the same level as
well as developing the 1,565 m level below. A
fully loaded Kiruna mine underground train hauls
1,608 t comprising one Schalke 108 t locomotive
and 21 NMT mining cars of 17 m 3 .
In Indonesia, NMT/Schalke are the primary
suppliers of underground rail solutions to PT
Freeport Indonesia, starting with the GBC mine
which handles some 60 Mt/y of copper/gold ore.
First production started with two autonomous
trains but is now expanding to ten trains as the
mine ramps up and the chute galleries come into
play. A fully loaded GBC mine train carries 708 t
and comprises one Schalke 40 t locomotive and
11 NMT mining cars of 20 m 3 . The locomotive is
designed with a hybrid power supply system,
featuring a pantograph for overhead catenary
and powerpacks for diesel or battery operation.
The powerpacks can be quickly and smoothly
replaced in approximately one hour as required.
This ModuTrac locomotive is therefore equipped
with several state-of-the-art traction technology
systems simultaneously.
The GBC mine uses MMT-M-270-BDE locos
with a total weight of 40 t, which are the next
generation of the locomotives operating at
Esmeralda mine, which is part of the El Teniente
mining complex operated by Codelco. This
ModuTrac locomotive is designed with a central
cab and is currently the heaviest twin-axle
locomotive Schalke manufactures. Each wheelset
is driven by a 135 kW AC electric traction motor.
Two state-of-the-art liquid-cooled IGBT-controlled
traction converters make it possible to control
each wheelset individually.
Some of the underground rail mining cars NMT
is supplying to Shougang's massive new
Macheng iron ore operation
20 International Mining | JUNE 2020