IPCC
TNT helping mines go SUPERPORTABLE ®
Terra Nova Technologies (TNT) told IM it has been busy with a number of
interesting projects in the last two years and is actively adapting and re-
introducing their highly flexible heap leach SUPERPORTABLE ® Mobile
Stacking Technologies for use in waste rock disposal for IPCC and dry tails
stacking.
Along with their JV construction partner Vial y Vives DSD, TNT recently
completed a crushing and conveying brownfields expansion at the BHP
Spence mine in Chile. The scope included a fully modular primary
gyratory station, the first of its kind in South America, complete with 27 m
high mechanically stabilised earth crusher wall, 33 modular structures
installed in 10 phases, a 60” X 113” – 750 kW gyratory crusher, associated
pollution control and a hydraulically driven 3 m wide sacrificial conveyor
complete with all electrical rooms, sub-stations and automation. The
station feeds 6,250 t/h of ore along a 54” wide and 3 km long overland
conveyor, equipped with belt condition monitoring and two 1,865 kW
WRIM drives, to the 200,000 t coarse ore stockpile. The modularised
station and stacking structure ensured fast schedule and lower
construction costs with record construction times.
TNT has also had a large 10,000 t/h SUPERPORTABLE ® multi-lift mobile
heap leach stacking system operating in excess of 95% availability for
more than 10 years at a South American copper mine. It also recently
commissioned for the same mining company another significant 6,500 t/h
SUPERPORTABLE ® multi-lift stacking system at a copper mine in the US.
This was the third system supplied by TNT to this mine, and the fifth
successful stacking system supplied to this customer. This most recent
system represented the latest advancements and technology that is the
culmination of years of advancements made working with this long-time
customer’s operational staff. In the first month of operations, they set
several daily records exceeding 130,000 t/d.
Underground crushing and conveying is another area where TNT has
expanded its offerings, having recently completed the delivery of
underground crushing and conveying, and surface conveying packages at
Lundin’s Neves Corvo mine in Portugal, as well as an underground
conveying system at Pumpkin Hollow in Nevada. TNT is also working on
the engineering for a complete crushing and underground to surface
conveying project in Canada, that will eventually convey both ore and
waste rock to surface, with waste rock being disposed of via a stacking
system into an old open pit.
Newmont Goldcorp recently awarded TNT the replacement of an
underground conveying system that was damaged in a fire at the
Musselwhite Mine in Canada. This venture into the underground arena
has led to an almost immediate integration into the Cementation
Group in their first year of their ownership of TNT, with the parent
company being responsible for varying degrees of underground mine
construction and installation on the Musselwhite Project. TNT also now
has several conveying and stacking solutions operating in extreme Arctic
conditions, including the Nordgold Gross project that operates at
temperatures down to -50 C in Siberia.
According to TNT’s Director of Project Development, Paul Emerson, TNT
is receiving a lot of interest from clients regarding the adaptation of their
SUPERPORTABLE ® technology into both dry stack tailings and waste rock
and overburden disposal due to the mobility, flexibility, as well as proven
high utilisation and availability when compared with alternate stacking
solutions. TNT has over the last year worked on numerous paid studies
and projects with multi-lift stacking plan development for a variety of new
projects and brownfield sites that often consider a variety of adaptations
of both tailings and waste material disposal. One project considers the
SUPERPORTABLE ® technology to stack rock abutments around an existing
wet tailings impoundment to increase the safety and volume. The system
International Mining | MAY 2020
The innovative modular primary gyratory at BHP Spence
also provides a more economical haulage of waste than traditional
truck/dump scenarios. Another project considered dry tails with complex
gradients and topography with stacking lift restrictions due to seepage
and geotechnical stability that essentially could not be contemplated
otherwise.
Yet another project considers the crushing, conveying and advance
stacking of PAG waste within a wet tailings empowerment so that the
tailings can flood the acid generating material to prevent ARD. And a
futher project considers conveying filtered tails and waste rock, with the
SUPERPORTABLE ® system essentially “mixing” the material through the
multiple transfer points at 76 m centres until disposed on the stacking
system and preventing liquefaction or segregation right before the
disposal onto the stacked area, thereby ensuring the best possible
encapsulation of acid generating waste rock and geotechnical stability.
“A big misconception related to the SUPERPORTABLE ® system is that
that multiple transfer points reduce the availability and utilisation. In
reality, TNT’s clients are advising that they are operating these systems at
high 95% plus availabilities.” According to Emerson, in the past the
arguments against the IPCC or dry tails solutions was that when one
conveyor shuts down, the system is down, whereas if one truck goes
down you are still operating. That is where the SUPERPORTABLE ® system
is similar to trucks since if any one of the string of mobile
SUPERPORTABLE ® conveyors has an unscheduled breakdown, it is simply
removed and replaced in a similar fashion to trucks. “In normal operation
this happens periodically and a SUPERPORTABLE ® is added in for advance
stacking or removed in retreat stack mode. Where high availability is
TNT's mobile conveyor systems for heap leach and tailings disposal are
both super portable as well as super flexible in operations