PASTE FLSMIDTH_proof 25/05/2016 09:38 Page 1
Paste Supplement
Embrace the unconventional
FLSmidth looks at innovations for better tailings
management solutions
FLSmidth’s Colossal™
pressure filter has a 2,080 m2
filtration area
e regularly read in the news about the
damage sustained from tailings
spillages and the human,
environmental, political and financial impact
they create. In the last few years alone, large
tailings disasters have re-focused attention on
mine safety and especially mining companies’
responsibility. These challenges cannot be taken
lightly and today’s mines are under more
scrutiny than ever before to be in compliance
with ever-increasing environmental regulations,
requiring more emphasis on long-term planning
for proper and safe tailings disposal and
management.
Tailings management challenges are not new
to the FLSmidth process and equipment experts.
In fact, FLSmidth’s tailings experience spans
over a century of research, development and
practical application to continually improve on
process technologies and not only meet today’s
demanding standards but also to prepare for
future requirements and legislation.
W
The need for sustainable tailings
management
The processes used in mineral extraction
produce enormous volumes of waste materials.
These tailings can make up as much as 98% of
the total ore mined. The leftover wet tailings
slurry mixture often contains close to 75% water
and, in many conventional plants, is pumped
directly into massive tailings ponds that allow
excess water to evaporate or dissipate back into
the soil.
P10 International Mining | JUNE 2016 Supplement
A traditional tailings pond takes up a large
area of land and requires a great deal of
maintenance and monitoring. Such ponds carry
a heightened risk for affected water to seep into
the groundwater or for dams to break, despite
precautions taken to protect the local
environment. The large surface area of the pond
also means that it will claim a higher percentage
of precipitation.
Wet tailings disposal is commonly identified
as the single most important source of impact
on long-term economic costs and environmental
concerns for many mining operations. What has
long been regarded as standard operating
procedure now needs to be replaced with more
responsible and maintainable mining practices.
Reducing the
need for tailings
ponds
FLSmidth’s dry tails
stacking disposal
bridges these evolving
mining paradigms and
effectively eliminates
the critical liabilities
associated with wet
tailings disposal.
Mining companies can
effectively reduce the
need for tailings ponds
A 22 m Deep Cone®
paste thickener
installed by FLSmidth
and instead promote ongoing reclamation and
revegetation of the surrounding landscape, thus
creating more favourable circumstances to
protect the environment and for obtaining and
renewing operating permits.
How is this done? Utilising FLSmidth’s
thickening, filtration, conveying and dry stacking
technologies; tailings can be effectively
dewatered and safely managed. An additional
and huge advantage is that water is recovered
and can be recycled for re-use in the plant’s
processes. When used for reclamation efforts,
customers quickly realise the added benefits of
FLSmidth’s tailings management solutions
which give the mine a long-term, responsible
and sustainable working solution.
Once mineral processing has taken place
within the plant, the remaining tailings are sent
to a sedimentation circuit to settle and thicken
the solids and to recover water. Thickened
underflow can be further dewatered using filters
to produce a stackable cake which can be
conveyed, minimising or eliminating the need
for dams.
Conventional thickeners
FLSmidth brings extensive experience to
thickening requirements having supplied over
10,000 thickeners and clarifiers to installations
worldwide. Correct thickener and clarifier sizing
and selection assures a margin of safety for
process upsets and allows the greatest
operational flexibility. This will include
determining settling rates, detention times
required for clarification, and the unit area and
solids-retention time required for thickening.
Although an older technology, FLSmidth is
constantly looking for ways to improve
thickening equipment and system operating
efficiencies, reduce maintenance costs, improve
process efficiencies, enhance functionality and