IPCC
necessary such as in a tails deposition application, we usually have a spare
stacker and stacker feed conveyors which effectively provides a redundant
system, particularly if there are an extra couple of spare
SUPERPORTABLES ® as well. Since you are adding and removing
SUPERPORTABLES ® in and out of the string TNT states that they can
usually arrange the stacking solutions in a manner that has the spare
stacker ‘share’ SUPERPORTABLES ® and provide a redundant system with
very little extra equipment making these systems extremely cost effective
and versatile.”
An example of redundant stacking systems depositing tails on a multi-
lift retreat stack is the redundant system operating at Ma’aden Phosphate
Company in Saudi Arabia. This system has dry stacked 35,000 t/d of
tailings since 2010 on a pad that has five lifts, each 10 m high, with an
eventual footprint of 1,200 m x 3,200 m. TNT is currently supplying the
third expansion for the dry stack tailings system. “This is an example of a
completely stable and safe tailings pad that has saved tremendous
amounts of water, and what we see as the new standard for tailings
systems.”
between the rotor and stator only being allowed to
deviate from the setpoint within small tolerances.
This is because deviations in the air gap reduce
the efficiency of the motor and, if the rotor and
stator were to make contact, it would damage the
motor.
The air gap is continuously monitored during
operation. If deformations and/or subsidence in
the steel structure or motor foundations lead to a
deviation in the air gap setpoint, the stator has to
be realigned. To simplify this process, the spacing
between the rotor and stator at the non-driven end
of the motor was fixed by a support bearing.
A membrane coupling compensates for
deformation of the pulley shaft caused by belt
tension. The adjustable motor frame facilitates
alignment of the motor during installation and
ensures simple realignment if necessary.
Eccentrics and spindles allow the stator to be
adjusted in all directions. Should a motor fail, it
can be quickly moved into a disabled position by
opening the membrane coupling and adjusting the
spindles. The system can then operate with
reduced power.
The landscape has been shaped by over 100 years
of mining, with, in addition to processing plants,
waste heaps, train tracks, roads, pipelines and
buildings. The challenge was to design an overland
conveyor system that took into consideration this
landscape for its entire length from the end of the
underground tunnel to the processing plant more
than 5 km away. A continuous single flight conveyor
was developed as follows:
n Distance of 5,330 m between the material
loading point and discharge with a difference in
height of 287 m
n Horizontal curves with tight radii (1,600 m to
2,300 m) on more than 60% of the conveyor
length
n Approximately 50% of the conveyor length on
elevated structure with variable lengths
According to Emerson, it is encouraging to see clients starting to engage
TNT directly much earlier in dry tails stacking and IPCC waste stacking
projects, which is key. “It is logical and easy to understand the advantages
of conveyor haulage versus trucks when considering the environment,
safety, water usage, carbon footprints, dust and OPEX. Making the
paradigm shift is more difficult because trucks are ‘easy’ and a known
quantity. However, by involving the OEM equipment suppliers early in the
design, the optimum use and application of their systems is better applied.
In reality, the CAPEX is generally similar, the OPEX is half or less and the
resulting cash flow/IRR are much improved when conveyors are maximised
in the mining process. Again, it is logical and common sense. With
conveyors as flexible and mobile as TNT’s SUPERPORTABLE ® systems,
many of the advantages of the trucks disappear. Water, CO 2 , dust and
labour will force us to all look at the best haulage systems for waste, ore
and tailings that are better for the environment and the bottom line. This is
where TNT sees the future of mining projects, and where we believe the
SUPERPORTABLE ® technology will excel due to the mobility, flexibility and
versatility of the design.”
adapted to local conditions for foundations
positioning and with support intervals of up to
96 m.
All loading points were optimised to reduce
conveyor belt wear. Newly designed transfer
chutes allow wear plates to be replaced quickly
and easily. A specially designed TAKRAF
maintenance vehicle travels along the conveyor
path, enabling the conveyor belt to be lifted and
worn idlers to be safely and efficiently replaced.
At the material discharge point, a bunker
building provides limited material storage. Two
feeder conveyors remove the material and feed it
to the processing plants. Three 5,000 kW direct
drive motors drive this conveyor, using a St 6,800
conveyor belt with a belt safety of S = 5.
McLanahan feeder breakers set for
Indonesian coal mine expansion
US-based McLanahan Corporation says it
continues its long-standing support of Indonesian
coal projects after being awarded an A$4.5 million
contract to supply custom-engineered Feeder-
Breakers to PT Bukit Asam. PT
Bukit Asam’s main sites are the
Air Laya, Muara Tiga Besar
North and West & Central Banko
mines with a combined
production of over 25 Mt/y.
The contract includes the
manufacture, assembly, supply
and commissioning on site for
two McLanahan FB48-50-46
Dump Hopper Feeder-Breakers
and one RFB48-50-49 Reclaim
Feeder-Breaker. The ROM Dump
Feeder Breakers will be
handling raw coal. Each
machine will be positioned
underneath a 150 t, 12 m long hopper allowing two
50 t rear dump trucks unloading from each side of
the hopper. All machines are being designed,
manufactured, assembled and shipped from
McLanahan’s Australian factory in Cameron Park,
NSW, where factory acceptance testing will also
be witnessed by the client’s representative.
“It’s a real thrill to be able to showcase our
technology to one of Asia’s most trusted coal
mining companies,” said Chris Knowles, Director
of Sales and Marketing at McLanahan. “As an
Australian OEM, we feel that our experience in
developing equipment focused on safety and ease
of maintenance, along with automation, was a big
factor in our selection. Of course, it helps to have
a partnership with the industry’s best service
provider, PT Suprabakti Mandiri. Pt Supra offers
highly trained local personnel who are able to
respond immediately and meet the needs of the
customer.
“Coming off the back of the most successful
year in our history, we see this new project as a
great start to the new year, and confirmation that
our continued investment in the region is well
supported,” Knowles said. IM
Similar McLanahan ROM Dump Feeder
Breakers to those being supplied to PT Bukit
Asam in Indonesia
MAY 2020 | International Mining 59