MINE HOISTS
Getting a handle
on hoisting
There are some really big projects set to come on-line in the
near term with record hoisting capacity, whilst on the
technology side there are still some new ideas, reports
Paul Moore
The scale and scope of hoisting projects for
some of today’s projects is impressive both
in terms of hoisting capacity and speed. At
Ivanhoe’s Platreef project on the Northern Limb of
South Africa’s Bushveld Igneous Complex, the
main production shaft is Shaft 2, located
approximately 100 m northeast of Shaft 1, which
will have an internal diameter of 10 m. It will be
lined with concrete and sunk to a planned, final
depth of more than 1,104 m below surface. It will
be equipped with two FLSmidth Koepe winding
plants, one equipped with 40 t rock-hoisting
skips capable of hoisting a total of 6 Mt/y of ore
– the single largest hoisting capacity at any mine
in Africa.
The headgear for the permanent hoisting
facility was designed by South Africa’s Murray &
Roberts Cementation. The box-cut excavation to a
depth of approximately 29 m below surface,
including the concrete foundation, has been
successfully completed and will form the
foundation of the 103 m tall concrete headgear
that will house the shaft’s permanent hoisting
facilities and support the shaft collar. Work on
Shaft 2 has been temporarily deferred while the
company completes its review of the phased
development production plan using Shaft 1 as the
mine’s initial production shaft.
Vedanta’s Hindustan Zinc Ltd (HZL), one of the
world’s largest zinc-lead-silver producers, in its
Q1 2020 report said that a major milestone had
been achieved with the start of ore hauling post
commissioning of the 955 m, 7.5 m diameter
production shaft during the quarter. While the
underground mine has been operating for a
number of years using the decline access, the
shaft completion will enable Rampura Agucha
Underground to finally achieve its slated ore
production capacity of over 5 Mt/y.
The underground mine also includes two
ventilation shafts, two declines from surface and
paste fill plants. The mining method is longhole
open stoping with paste filling. The open pit mine
in the same complex has been operating since
1990. The three shaft hoists were all supplied by
ABB and consist of two friction hoists and one
single drum hoist. The sinking of the three shafts
was all contracted to Shaft Sinkers back in 2012
but significant delays have been experienced as
that company faced severe financial difficulties; it
went on to be acquired by UMS Group in 2015.
At Oyu Tolgoi, Shaft 2 construction was
completed in October 2019, and was fully
commissioned in
February 2020. With
a depth of 1,284 m it
is the main
production shaft and
primary access point
for people and
materials and
provides
infrastructure for the
materials handling
system in the
underground mine.
Its ABB production
hoist is the largest
Koepe rope hoist
system in the world
with two 60 t
capacity skips capable of hoisting 28,000 t of ore
per day at a maximum speed of 59 km/hr. Shaft 2
can carry 300 people per cage cycle versus a
The ABB Koepe hoist for Shaft 2 at Oyu Tolgoi
maximum of 60 people per cage cycle through
Shaft 1. Shaft 2’s hoist rope-up process took 23
days by a team of approximately 500 people –
one of the safest and most efficient rope-ups
undertaken anywhere in the world.
FLSmidth sees increasing NA demand
Matt Goddard, Global Product Director, Mine
Shaft Systems at FLSmidth,told IM: “Our recent
hoist installations include two hoists in Ontario,
Canada, in a copper mine. These were installed
and commissioned in early 2019 and were just
coming up on their one year inspection in July
2020. They were two 5 m double drum hoists,
including production and service. Hoist enquiries
in the North American Region are growing rapidly
over the last year.” He added that in terms of
technology, its Crank Type Dump Mechanism
(CTDM), which reduces the overall cycle time
through synchronised loading and discharging,
leading to potential production increases, is
getting a lot of attention and the company is
anticipating a first installation soon. Goddard
adds: “Globally, we are chasing a few different
orders for potential hoists this year with quite
few feasibility inquiries for some very large
installations in the coming years in North
America.”
FLSmidth says it is also currently in the
process of expanding its steel guide safety brake
for conveyances to four large guide cages. It is
shipping a two guide conveyance to Finland
shortly, which is equipped with the technology.
“This technology is all about safety and has the
potential to save the customer significant amount
of money in maintenance of mine shafts
replacing wood guides while protecting the
miners.”
FLSmidth says it is seeing quite a few feasibility
enquiries for some very large hoist installations
in the coming years in North America
78 International Mining | JULY/AUGUST 2020