2
as “slurry”). For the sandy tailings generated in the flotation
process, SAMARCO adopted dewatering using vacuum
disc filters, followed by dry stacking disposal. The figure
below provides a simplified overview of the production
process, highlighting the two types of tailings generated.
Several studies are underway to enable the dry stack-
ing of dewatered ultrafine tailings, either independently
or co-disposed with sandy tailings and/or waste rock. Dry
Stacking technology emerges as an alternative for tailings
disposal in a scenario that does not require tailings dams.
Multiple studies have been conducted to evaluate this
approach, particularly the geotechnical aspects related to
the workability and trafficability of these tailings’ mixtures.
The dewatering process for these tailings is essential to
achieve optimal moisture content for subsequent compac-
tion. Among available filtration technologies, the two pri-
mary options are filter presses and vacuum disc filters.
Brazilian filtration plants have been optimizing oper-
ational parameters such as pulp density, particle size dis-
tribution, filtration equipment, filter media, pressure and
filtration times to achieve the dry-stacking KPIs. In addi-
tion, to overcome the challenges of capillary forces plus
ultrafine particles, chemical additives are being studied to
improve tailings filtration performance. Flocculants, surfac-
tants, and coagulants have been evaluated as filter aids. It is
well known that chemicals can modulate the desired surface
chemistry by changing the zeta potential of particles, the
pulp rheology and the fluid surface tension, which results
in modifying floc dimensions, structure and strength, as
well as the pulp viscosity and the wettability of particles
(Mamghaderi et al., 2021). Filter aids improve specific cake
resistance and cake formation time, ultimately reducing
cake moisture and maximizing filtration rates. While the
effectiveness of filter aids when filtering concentrates is well
established, laboratory and plant testing have shown that
the chemical solutions that are efficient for filtering concen-
trates are often not suitable for tailings filtration.
Thus, the filter aids designed specifically for tailings
plays a crucial role in enhancing the dewatering efficiency
of tailings mixtures, facilitating optimal moisture reduction
for dry stacking.
FLOTICOR FA series are presenting formulations
with superior performance for filtration of tailings with the
presence of ultrafines (FAUSTINO et al., 2023 COSTA
2021).
Taylor made polymers aggregate mineral particles in
a desired size, avoiding water to be confined inside these
structures. Laboratory trials with samples composed by
coarse tailings from flotation process and varying percent-
age of ultrafines (5 to 20%) from desliming process in iron
ore industry indicated at least double-fold filter rates, as
shown in Figure 2.
Considering the improved performance achieved with
the FLOTICOR FA series for tailings filtration at the labo-
ratory scale, the next step was to understand how the use of
these products would perform at an industrial scale.
Given SAMARCO’s extensive experience with vacuum
disc filters in pellet feed and flotation tailings filtration,
the use of this technology for dewatering tailings mixtures
(sandy tailings and ultrafine tailings) was preliminarily
evaluated
through leaf tests (VIEIRA et al., 2023). The results,
especially for the 90/10 mixture (90% sandy tailings and
10% ultrafine tailings), motivated industrial testing at
SAMARCO’s sandy tailings filtration plant.
Figure 2. Laboratory filtration results (leaf test bottom-feed) with the filter aid FLOTICOR FA 17416
as “slurry”). For the sandy tailings generated in the flotation
process, SAMARCO adopted dewatering using vacuum
disc filters, followed by dry stacking disposal. The figure
below provides a simplified overview of the production
process, highlighting the two types of tailings generated.
Several studies are underway to enable the dry stack-
ing of dewatered ultrafine tailings, either independently
or co-disposed with sandy tailings and/or waste rock. Dry
Stacking technology emerges as an alternative for tailings
disposal in a scenario that does not require tailings dams.
Multiple studies have been conducted to evaluate this
approach, particularly the geotechnical aspects related to
the workability and trafficability of these tailings’ mixtures.
The dewatering process for these tailings is essential to
achieve optimal moisture content for subsequent compac-
tion. Among available filtration technologies, the two pri-
mary options are filter presses and vacuum disc filters.
Brazilian filtration plants have been optimizing oper-
ational parameters such as pulp density, particle size dis-
tribution, filtration equipment, filter media, pressure and
filtration times to achieve the dry-stacking KPIs. In addi-
tion, to overcome the challenges of capillary forces plus
ultrafine particles, chemical additives are being studied to
improve tailings filtration performance. Flocculants, surfac-
tants, and coagulants have been evaluated as filter aids. It is
well known that chemicals can modulate the desired surface
chemistry by changing the zeta potential of particles, the
pulp rheology and the fluid surface tension, which results
in modifying floc dimensions, structure and strength, as
well as the pulp viscosity and the wettability of particles
(Mamghaderi et al., 2021). Filter aids improve specific cake
resistance and cake formation time, ultimately reducing
cake moisture and maximizing filtration rates. While the
effectiveness of filter aids when filtering concentrates is well
established, laboratory and plant testing have shown that
the chemical solutions that are efficient for filtering concen-
trates are often not suitable for tailings filtration.
Thus, the filter aids designed specifically for tailings
plays a crucial role in enhancing the dewatering efficiency
of tailings mixtures, facilitating optimal moisture reduction
for dry stacking.
FLOTICOR FA series are presenting formulations
with superior performance for filtration of tailings with the
presence of ultrafines (FAUSTINO et al., 2023 COSTA
2021).
Taylor made polymers aggregate mineral particles in
a desired size, avoiding water to be confined inside these
structures. Laboratory trials with samples composed by
coarse tailings from flotation process and varying percent-
age of ultrafines (5 to 20%) from desliming process in iron
ore industry indicated at least double-fold filter rates, as
shown in Figure 2.
Considering the improved performance achieved with
the FLOTICOR FA series for tailings filtration at the labo-
ratory scale, the next step was to understand how the use of
these products would perform at an industrial scale.
Given SAMARCO’s extensive experience with vacuum
disc filters in pellet feed and flotation tailings filtration,
the use of this technology for dewatering tailings mixtures
(sandy tailings and ultrafine tailings) was preliminarily
evaluated
through leaf tests (VIEIRA et al., 2023). The results,
especially for the 90/10 mixture (90% sandy tailings and
10% ultrafine tailings), motivated industrial testing at
SAMARCO’s sandy tailings filtration plant.
Figure 2. Laboratory filtration results (leaf test bottom-feed) with the filter aid FLOTICOR FA 17416