IPCC
FLSmidth semi mobile
crushing stations, part
of an IPCC solution
provided to Barmer
Lignite Mining
Company Limited
(BLMCL) in Rajasthan,
India
Karara opts for mobile stacking
conveyor technology
Bis, FLSmidth and Karara Mining have developed a
“unique mobile stacking conveyor” solution that
has cut water use, costs and the environmental
footprint at the iron ore miner’s operation in
Western Australia.
If Karara’s iron ore mine had chosen a wet
tailings storage facility, the tailings pond would
have been roughly 8 km 2 based on its 30-year
mine life, according to FLSmidth.
The operation is also in the Mid-West region of
Western Australia, an area with scarce water
reserves, so losing so much water to wet tailings
would have been costly to both the environment
and Karara’s bottom line.
With these factors in mind, Karara looked at
implementing a dry-stacked/filtered tailings
system to allow for significant water recovery and
reuse. As well as reducing costs, dry stack
technology would reduce the tailings footprint to
around 4 km2, according to FLSmidth.
Bis worked with Karara and FLSmidth to
develop a solution to build, own, operate and
maintain a “unique mobile stacking conveyor”,
FLSmidth said. This fixed infrastructure solution
was developed by the three companies to
integrate a walking conveyor and stacking
technology normally used in large-scale copper
mining operations.
Aside from the significant reduction of the
physical footprint compared with the wet tailings
alternative, Karara was looking for cost efficiencies
in other areas, FLSmidth said. “For instance, the
planning of a wet tailings storage facility needs to
factor in an ongoing maintenance strategy. This
comes with a perpetual cost that can only be
guessed at while the decades pass,” the company
said. “With dry-stack tailings, the total cost of
ownership over the mine’s lifetime is easier to
estimate and Karara were confident the dry stack
solution would be cost competitive.”
Water usage was another key consideration for
Karara. With environmental and cost factors in
mind, Karara wanted to look at ways to have
greater control over water assets on site. The
ability to reuse and recycle water in the mining
process would lead to substantial cost efficiencies
by minimising the amount of makeup water
needed for the mining
operation, FLSmidth
said.
The technology
implemented into
Karara’s tailings storage facility was also an
important factor as Karara wanted the flexibility to
continually update the equipment with the view of
running it more efficiently as new technology
became available. It engaged Bis to operate the
facility machinery based on its deep industry
experience with materials handling and bulk
logistics, FLSmidth said.
FLSmidth, meanwhile, was identified by Karara
as being able to meet the project’s requirements
and mine-specific needs. The mining OEM said: “A
primary demand was the ability to supply a cost-
effective dry stacking technology ideal for dry
climate mining operations that reduced water
requirements. With FLSmidth’s advanced stacking
capability (machinery working off stacked pile) and
ability to stack tailings at 15% moisture content,
this meant tangible water savings for Karara.
“At Karara, the dry tailings will be stacked in
four lifts to the maximum height approved by the
MAY 2020 | International Mining 51