4
various scales—from laboratory to industrial. Metso has
systematically incorporated CFD modeling, particularly
in the early stages of development. This approach allows
for the early identification of promising design concepts,
saving resources and accelerating the eventual productiza-
tion of commercially viable designs. CFD modeling is not
limited to these early stages and remains utilized through-
out the entire development process, primarily to validate
experimental results as the project progresses.
FLOATFORCE®+ DESIGN JOURNEY
The development of FloatForce+ began in 2019 with the
ideation phase which involved an extensive team of Metso
experts. The outcome of that phase was the definition of
a series of requirements that the new mechanism design
should achieve, considering as a starting point or mini-
mum requirements, those already achieved by its predeces-
sor design, the FloatForce.
Next phase involved brainstorming sessions for new
design concepts that could meet the additional require-
ments of a new rotor and stator. CFD modelling progressed
immediately after, utilizing multiple possible designs based
on the conceptualization carried out in the previous phase,
This CFD modeling allowed comparison of some key per-
formance indicators such as power draw and several hydro-
dynamic parameters, in relation to the existing mixing
mechanism design. This process was executed iteratively
over the following two years, involving the review and
reworking of ideas and concepts, contrasting the results
of the CFD modelling with experimental results at differ-
ent scales, mainly involving a 45-liter laboratory cell and
a 1 m3 TankCell ®. This phase concluded with an in-depth
evaluation by screening the 3 rotor designs that showed
the most promising results during the iteration process. All
this research was carried out at the Metso Research Center
facilities located in Pori, Finland.
The outcome of the concept development phase was
the selection of the design that best fit the performance
requirements defined at the beginning of the development
journey. The FloatForce+ basic shape is similar to the pre-
vious FloatForce and its main features were kept, which
included its differentiated channels for both air and slurry.
This ensured the new design would still provide the well-
recognized high mixing capacity, even at high air rates. The
most noticeable difference of the FloatForce+ rotor design
are the added top holes, which provide improved pump-
ing and re-mixing in the region directly above the rotor,
while still maintaining the required quiescent zone. Most
of the CFD modelling performed around the final concept
showed a higher turbulent kinetic energy and improved
energy dissipation rate along with an even turbulence dis-
sipation through the tank, compared to FloatForce. One
example of these simulations is shown in Figure 4.
As introduced above, the FloatForce+ basic shape is
close to the previous design, but optimized for increased
pumping effectiveness and reduced power draw along with
a sustainable manufacturing. The new FloatForce+ rotor
shape design is shown in Figure 5. The stator design was
also optimized but is not shown here since it is still moving
forward with an industrial scale evaluation with the rotor
in a second assessment stage where it is expected to validate
its new features.
A key design requirement during development was that
the new FloatForce+ mechanism can be directly placed in
existing Metso legacy flotation cells, without the need for
any retrofit design or work. This still allows the same retro-
fit capability that FloatForce has with third party machines.
It will be available in the same sizes, setup, and connect-
ing dimensions as all legacy mechanisms. The final scope
of supply when upgrading to FloatForce+ will be based on
the specific current installation baseline. As an example, the
simplest case will be upgrading from a current FloatForce ®
setup, only involving a plug and play rotor/stator change.
As the final concept definition was completed, the
selected design was manufactured for a 160 m3 TankCell to
allow evaluation at industrial scale. This evaluation was car-
ried out in late 2021 in a site located in the Nordics. Some
key results of this first evaluation are shown in this work.
Further metallurgical assessments at different sites involv-
ing larger volume cells and the complete FloatForce+ rotor/
stator setup are currently ongoing.
Table 2. FloatForce® references results summary
Result
Increased overall
recovery X X X X X X X X
Increased coarse
particle recovery X X X X
Lower energy
consumption X X X X X
Improved
maintenance X X
Cesnik,
F.,
2009
Gamez
et
al.,
2011
Valdivia
et
al.,
2011
Outotec,
2011
Leon
and
Porras,
2013
Yianatos
et
al.,
2012
Bird
et
al.,
2015
Morgan
et
al.,
2017
Morgan
et
al.,
2021
various scales—from laboratory to industrial. Metso has
systematically incorporated CFD modeling, particularly
in the early stages of development. This approach allows
for the early identification of promising design concepts,
saving resources and accelerating the eventual productiza-
tion of commercially viable designs. CFD modeling is not
limited to these early stages and remains utilized through-
out the entire development process, primarily to validate
experimental results as the project progresses.
FLOATFORCE®+ DESIGN JOURNEY
The development of FloatForce+ began in 2019 with the
ideation phase which involved an extensive team of Metso
experts. The outcome of that phase was the definition of
a series of requirements that the new mechanism design
should achieve, considering as a starting point or mini-
mum requirements, those already achieved by its predeces-
sor design, the FloatForce.
Next phase involved brainstorming sessions for new
design concepts that could meet the additional require-
ments of a new rotor and stator. CFD modelling progressed
immediately after, utilizing multiple possible designs based
on the conceptualization carried out in the previous phase,
This CFD modeling allowed comparison of some key per-
formance indicators such as power draw and several hydro-
dynamic parameters, in relation to the existing mixing
mechanism design. This process was executed iteratively
over the following two years, involving the review and
reworking of ideas and concepts, contrasting the results
of the CFD modelling with experimental results at differ-
ent scales, mainly involving a 45-liter laboratory cell and
a 1 m3 TankCell ®. This phase concluded with an in-depth
evaluation by screening the 3 rotor designs that showed
the most promising results during the iteration process. All
this research was carried out at the Metso Research Center
facilities located in Pori, Finland.
The outcome of the concept development phase was
the selection of the design that best fit the performance
requirements defined at the beginning of the development
journey. The FloatForce+ basic shape is similar to the pre-
vious FloatForce and its main features were kept, which
included its differentiated channels for both air and slurry.
This ensured the new design would still provide the well-
recognized high mixing capacity, even at high air rates. The
most noticeable difference of the FloatForce+ rotor design
are the added top holes, which provide improved pump-
ing and re-mixing in the region directly above the rotor,
while still maintaining the required quiescent zone. Most
of the CFD modelling performed around the final concept
showed a higher turbulent kinetic energy and improved
energy dissipation rate along with an even turbulence dis-
sipation through the tank, compared to FloatForce. One
example of these simulations is shown in Figure 4.
As introduced above, the FloatForce+ basic shape is
close to the previous design, but optimized for increased
pumping effectiveness and reduced power draw along with
a sustainable manufacturing. The new FloatForce+ rotor
shape design is shown in Figure 5. The stator design was
also optimized but is not shown here since it is still moving
forward with an industrial scale evaluation with the rotor
in a second assessment stage where it is expected to validate
its new features.
A key design requirement during development was that
the new FloatForce+ mechanism can be directly placed in
existing Metso legacy flotation cells, without the need for
any retrofit design or work. This still allows the same retro-
fit capability that FloatForce has with third party machines.
It will be available in the same sizes, setup, and connect-
ing dimensions as all legacy mechanisms. The final scope
of supply when upgrading to FloatForce+ will be based on
the specific current installation baseline. As an example, the
simplest case will be upgrading from a current FloatForce ®
setup, only involving a plug and play rotor/stator change.
As the final concept definition was completed, the
selected design was manufactured for a 160 m3 TankCell to
allow evaluation at industrial scale. This evaluation was car-
ried out in late 2021 in a site located in the Nordics. Some
key results of this first evaluation are shown in this work.
Further metallurgical assessments at different sites involv-
ing larger volume cells and the complete FloatForce+ rotor/
stator setup are currently ongoing.
Table 2. FloatForce® references results summary
Result
Increased overall
recovery X X X X X X X X
Increased coarse
particle recovery X X X X
Lower energy
consumption X X X X X
Improved
maintenance X X
Cesnik,
F.,
2009
Gamez
et
al.,
2011
Valdivia
et
al.,
2011
Outotec,
2011
Leon
and
Porras,
2013
Yianatos
et
al.,
2012
Bird
et
al.,
2015
Morgan
et
al.,
2017
Morgan
et
al.,
2021