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IPCC
Dos Santos high angle conveyors for Colombia gold miner
Dos Santos International recently commissioned two Sandwich belt high
angle conveyors for Continental Gold’s Buriticá project in Antioquia,
Colombia. The DSI Sandwich high angle conveyors will serve as transfer
conveyors elevating crushed pebble ore, each at a rate of 135 t/h, and
operating at an incline angle of 45°. While not IPCC per se, the same
technology is highy applicable within the pit as well, and DSI has also
supplied IPCC solutions.
These two systems were rationalised to be the same belt width, and to
use the same mechanical equipment (idlers, drives, pulleys, belt, etc).
However, the first unit achieves a higher lift and length than the other.
Unit 1, adjacent to the grinding SAG mill has a lift of 14,250 mm and a
length of 34,100 mm. It feeds a crusher, when then feeds the second
Sandwich conveyor. That unit has a shorter lift and length at 6,750 mm
and 17,500 mm, respectively. Unit 2 elevates the pebble ore outside of the
building and discharges onto a conveyor which also delivers stockpiled
material into the building.
Early in the commissioning process, Continental Gold determined that
a conventional conveyor on the site (not supplied by DSI) would need to
be modified from a simply supported structure to a cantilevered head
end. Continental reached out to DSI for their structural engineering
expertise, and the additional task was completed quickly and
economically. Though the new steel was procured by the site personnel,
DSI ensured that the modifications could be made with minimal
additional cost. The result was an elegant strut design that maintained
the support at the head end, while also incorporating modifications to
allow for access to important equipment.
This is the second gold project on which DSI has cooperated with M3
Engineering. DSI also executed a contract through M3 for an overland
conveyor system at Goldcorp’s Los Filos Project in the Nukay mining
district of central Guerrero State in Southern Mexico.
The long-hole open stoping mining method will be employed to extract
high-grade ore from the underground deposit. Cut-and-fill method and
inherently share the same benefits associated
with highly efficient, lower-risk, conventional belt
conveyors. Faster removal of material at higher
tonnage rates, continuous haulage, conveying
irregular-shaped spoil with moisture content
ranging from dry to very wet, has now been proven
numerous times by using vertical sandwich belt
technology.”
Capacities of more than 4,500 t/h and lifts
greater than 175 m have been achieved. "The use
of a simple - yet effective - spring-loaded pressing
device provides the proper amount of hugging
pressure required to produce the right amount of
friction between material and the belt, and the
internal friction of material on material to help
prevent slide back from occuring when designed
per customer-supplied criteria. This gentle
hugging pressure is also considered self-
regulating as the amount of pressure applied to
the belts is dependent on the depth of material
being conveyed."
As the bed depth increases, so does spring
compression, thereby introducing more pressure
on the belts. Komatsu is now incorporating its
sizer product in their HAC systems to crush the
material to a cubic, conveyable size.
International Mining | MAY 2020
shrinkage stoping methods will be applied to extract lower quality ore.
The Buritica underground ore body will be accessed via three ramps
namely South ramp, Yaraguá ramp, and the Higabra valley tunnel. The
mining rate will initially be 2,100 t/d and will be ramped up to 3,000 t/d
by the third year.
DSI Sandwich belt high angle conveyors take on many forms the
company says they offer many advantages. "Each DSI Sandwich Conveyor
uses two standard, smooth-surfaced conveyor belts, face-to-face, to
gently but firmly contain the product being carried. This not only makes
steep angles possible; it also offers a spillage free, environmentally
sound operation because the material remains secured between the
belts. A DSI sandwich conveyor is capable of higher conveying speeds
and greater capacities than other high angle conveying methods. With the
availability of wider belts and accompanying hardware, capacities greater
than 10,000 t/h can be easily achieved with a DSI Sandwich conveyor.
High angles of 90° are typical, and lifts of 300 m are easily accomplished.
The use of all conventional conveyor parts ensures high availability and
low maintenance costs, as well as interchangeability of components and
fast delivery of replacement parts."
The second DSI Sandwich belt conveyor at Continental Gold’s Buriticá
project is fed by the first
TAKRAF’s journey at Chuquicamata
Underground
In 2019, Codelco’s Chuquicamata mine – situated
in northern Chile and one of the world’s largest
copper mines – was converted from an open-pit
mine to an underground operation. Over 100
years of open-pit mining had resulted in a mine
that was some 1,000 m deep, 5,000 m long and
3,000 m wide. Once the rock had been mined by
drilling and blasting, the ore and waste material
was transported to surface by trucks for
processing or for disposal.
However, it was becoming no longer
economically viable to mine deeper ore bodies
using this process. Moreover, longer truck routes
combined with a larger number of vehicles
resulted in higher costs for vehicle maintenance
and fuel, greater environmental pollution and
safety concerns.
In 2015, Tenova TAKRAF was awarded the
contract to supply the principal ore transportation
system moving crushed copper ore from
underground storage bins to the surface
processing site. Mario Dilefeld, Head of Belt
Conveyor Systems at TAKRAF outlined the project
in some detail to IM.
The system called for no redundancies, which
meant that high system availability, minimal
system wear and easy maintenance of
components were critically important. The project
scope called for removal of crushed ore from 60 m
high underground storage bins with a conveying
capacity of 11,000 t/h, transportation to the
surface with a minimum number of material
transfer points, and conveying of the ore from the
underground tunnel exit to the existing processing
plant, taking into account existing infrastructure.
In designing the system, numerous innovations
resulted in six patents being implemented for the
first time, resulting in a modern, powerful and
environmentally friendly conveyor system. Highly
efficient electric drive motors replaced diesel truck
engines and as a result, CO 2 emissions produced
by transporting the material have been reduced by
more than two thirds for the same copper
production volume.
TAKRAF employed a feeder conveyor in place of
conventional belt conveyors for controlled
material discharge. The conveyor belt has a 45
degree trough angle along the entire conveyor
route, with the only chutes being in the storage
bin discharge area. The contour of the material