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The Role of Pulp Solids And Residence Time on Metallurgical
Performance of Concorde Cell™
Berivan Tunç, Sebastian Nikolov, Nathaliea Kupka, Rodrigo Grau, Alejandro Yáñez
Metso Finland
ABSTRACT: The Concorde Cell was invented and patented by Professor Jameson of the University of Newcastle
to be dedicated to fine-ultrafine flotation. In this paper, the effect of pulp solid and residence time has been
studied with fine-ultrafine liberated hydrophobic minerals in Concorde Cell. Blast tube residence time varied by
manipulating the feed flow rate and changing the Blast Tube capacity. In the second part of the study, the effect
of pulp solid was tested by considering the challenges of high solid content in ultrafine flotation.
INTRODUCTION
The challenges in fine flotation derive from their natural
physical and chemical properties. Fine–ultrafine particles
have a high surface area, low momentum, small mass, and
high surface energy, and therefore they bring some diffi-
culties such as high oxidation rate, low energy for bubble
attachment, high viscosity, high reagent consumption, and
entrainment (Farrokhpay et al., 2021 Pease et al., 2006).
Since fine particles have low momentum because of
their small mass, the kinetic energy required to intervene
to bubble liquid film is too small (Dobby &Finch, 1987).
Ultimately, providing more energy input will result in suc-
cessful bubble particle attachment (Miettinen et al., 2010)
The successful bubble-particle capture process is
controlled by the efficiency of three variables collision,
attachment, and stability (Dai et al., 1999). In flotation,
detachment matters if centrifugal forces are applied to a
particle exceeding the adhesive force of surface tension. In
turbulent flow rotation speed of microbubbles in their cen-
ter would be greater than large bubbles in turbulent flow
(Ahmed &Jameson, 1985). According to this theory, cen-
trifugal forces affect the particles attached to microbubbles
more. However, centrifugal forces exerted on a particle vary
as the cube of particle size, whereas surface tension is the
square of the particle, meaning that as particle size dimin-
ishes, consequentially, adhesive forces become significantly
more dominant than centrifugal forces (Jameson, 2010a).
It is evident that once fine particles are attached to a bub-
ble, it is unlikely that detachment will take place. In this
regard, It has been made clear that more attention should
be paid to ensuring high collision efficiency for increasing
the flotation rate of fine particles (Schubert, 2008).
Collision efficiency is strongly dependent on particle
size and bubble size. Efficiency varies as the square of the
particle size and inversely as the square of bubble size (Yoon
&Luttrell, 1989). This correlation shows that reducing
bubble size can improve collision probability in fine flo-
tation. Yoon (2000) experimentally showed that for fine
particles with a diameter of 11.4 µm, collision efficiency is
high where the bubbles are smaller than 100 µm however,
as bubble size increases, collision efficiency reduces signifi-
cantly. Even though the strong relation between flotation
kinetic rate and bubble size is experimentally supported,
its effect is dependent on many variables such as shear rate,
power input, the velocity of the bubble, particle size, and
density (Ahmed &Jameson, 1985 Hassanzadeh et al.,
2019 Jameson et al., 2007).
The Role of Pulp Solids And Residence Time on Metallurgical
Performance of Concorde Cell™
Berivan Tunç, Sebastian Nikolov, Nathaliea Kupka, Rodrigo Grau, Alejandro Yáñez
Metso Finland
ABSTRACT: The Concorde Cell was invented and patented by Professor Jameson of the University of Newcastle
to be dedicated to fine-ultrafine flotation. In this paper, the effect of pulp solid and residence time has been
studied with fine-ultrafine liberated hydrophobic minerals in Concorde Cell. Blast tube residence time varied by
manipulating the feed flow rate and changing the Blast Tube capacity. In the second part of the study, the effect
of pulp solid was tested by considering the challenges of high solid content in ultrafine flotation.
INTRODUCTION
The challenges in fine flotation derive from their natural
physical and chemical properties. Fine–ultrafine particles
have a high surface area, low momentum, small mass, and
high surface energy, and therefore they bring some diffi-
culties such as high oxidation rate, low energy for bubble
attachment, high viscosity, high reagent consumption, and
entrainment (Farrokhpay et al., 2021 Pease et al., 2006).
Since fine particles have low momentum because of
their small mass, the kinetic energy required to intervene
to bubble liquid film is too small (Dobby &Finch, 1987).
Ultimately, providing more energy input will result in suc-
cessful bubble particle attachment (Miettinen et al., 2010)
The successful bubble-particle capture process is
controlled by the efficiency of three variables collision,
attachment, and stability (Dai et al., 1999). In flotation,
detachment matters if centrifugal forces are applied to a
particle exceeding the adhesive force of surface tension. In
turbulent flow rotation speed of microbubbles in their cen-
ter would be greater than large bubbles in turbulent flow
(Ahmed &Jameson, 1985). According to this theory, cen-
trifugal forces affect the particles attached to microbubbles
more. However, centrifugal forces exerted on a particle vary
as the cube of particle size, whereas surface tension is the
square of the particle, meaning that as particle size dimin-
ishes, consequentially, adhesive forces become significantly
more dominant than centrifugal forces (Jameson, 2010a).
It is evident that once fine particles are attached to a bub-
ble, it is unlikely that detachment will take place. In this
regard, It has been made clear that more attention should
be paid to ensuring high collision efficiency for increasing
the flotation rate of fine particles (Schubert, 2008).
Collision efficiency is strongly dependent on particle
size and bubble size. Efficiency varies as the square of the
particle size and inversely as the square of bubble size (Yoon
&Luttrell, 1989). This correlation shows that reducing
bubble size can improve collision probability in fine flo-
tation. Yoon (2000) experimentally showed that for fine
particles with a diameter of 11.4 µm, collision efficiency is
high where the bubbles are smaller than 100 µm however,
as bubble size increases, collision efficiency reduces signifi-
cantly. Even though the strong relation between flotation
kinetic rate and bubble size is experimentally supported,
its effect is dependent on many variables such as shear rate,
power input, the velocity of the bubble, particle size, and
density (Ahmed &Jameson, 1985 Hassanzadeh et al.,
2019 Jameson et al., 2007).