HIGH PROFILE
How mining stacks up
Paul Moore spoke with FLSmidth Director of Tailings, Todd
Wisdom, covering water saving, desalination & new
tailings technology adoption
Q The big water challenges are being met with
technology like paste tailings and dry-stack
tailings – yet still there has been little actual
deployment of these solutions when you consider
the whole mining industry. Part of this is a lack of
experience and the planning involved, are things
speeding up since Brumadindo?
A There has historically been a slow adoption of
high performance tailings dewatering equipment
for larger mines but recently there has been
some movement. For instance, there have been
over 30 vacuum filters purchased from FLSmidth
in Brazil for tailings dewatering. We are also
seeing customers taking a more life-cycle
approach to costs – and when that happens, dry
stack, or filtered tailings, often comes into play
when the cost of water is taken into account or as
post-closure costs are reduced, for instance. Risk
and regulation are also factors that are
increasingly impacting decision making and
driving a change in the adoption rates of new
technologies.
70 International Mining | APRIL 2020
Q Many big mines in arid regions are phasing in
desalination plants. What implications does this
“new water” have for process equipment in terms
of chemistry etc?
A There have been some corrosion issues
associated with desalinated water and there are
also potential issues with the high-salt
concentration brine that is discharged from a
desalination plant. There is growing concern that
this could have a negative impact on the local sea
environment around the desalination plant. But
using desalination means that you do not
compete with the local community and other
industries for fresh water. But though the use of
untreated seawater or desalination has been a
viable option for some, it can come at substantial
cost because it may require many kilometres of
piping to connect the processing plant to the
water source. That can be very energy intensive
and expensive. Desalination removes competition
with the local community and other industries for
fresh water, but it does not address a number of
related risks with managing the water and tailings
afterwards. This includes tailings that have been
contained behind dams, leaving mine owners with
large pools to maintain and manage for the long
term, the immense liability of potential tailings
dam failures, and community concerns over dam
breakages or overflow risk.
Q Will it ever be possible for a
process plant to achieve a near
closed loop in terms of water
consumption?
A A near closed loop, yes. There will
always be some water that is lost in
the filter cake. As the water balance
closes there may need to be some
water treatment conducted to keep
impurities from building up and
impacting metal recoveries. This type of water
treatment is available and is on the market today.
The FLSmidth Colossal Filter demo plant at a
concentrator in the Atacama region in Chile
Q As a company how important is water saving
now at a technology development level?
A This is very important to FLSmidth and a key
part of our strategy and R&D efforts. We have
focused on improving tailings dewatering
equipment for some time and we are also looking
at other areas across the mining flowsheet. Late
last year, we launched MissionZero, our ambition
to enabling our customers to move towards zero
water waste, zero emissions and zero energy
waste by 2030. This is a very tangible and
solution-based ambition that will deliver
significant and quantifiable benefits to our
customers and the industry, making mining more
efficient, cost efficient and, of course, sustainable.
Already, we have solutions such as dry-stack, or
filtered, tailings that enables our customers to
recover up to 95% of their process water and
multiple digital solutions that provide greater
processing efficiency. But we are also identifying
opportunities to significantly improve customers’
productivity and reduce environmental impact
across the entire mining flowsheet, including
crushing, flotation, thickener upgrades and
filtration, as well as the potential of pumps and
cyclones. MissionZero is also an invitation to
customers, third parties and our peers to co-
create and ensure adoption of solutions that will
transform mining into a more sustainable
industry. We are asking them to join us on this
journey.
Q This year, the Global Tailings Review will report
back with new industry standards. Do you think
this will add momentum to the action mining
companies are already taking in assessing current
and future TSFs? What role is FLSmidth playing in
all these reviews and discussions?
A FLSmidth has presented our EcoTails ® solution
and our new 5 m x 3 m filter, capable of filtering
30,000 tonnes per day per filter, to ICMM. Both
technologies are ready for full scale operation,
likely at a demonstration type facility. Pilot testing
has been successfully completed for the EcoTails
Part of a demonstration of the largest filter
press plate ever built, the 5 m x 3 m AFP, for the
EcoTails project