XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 2367
increasing collector dosage, particles became more hydro-
phobic, and this enhance the agglomeration of particles
based on the hydrophobic interaction (Takamori 1985). As
a result, apparent agglomerate particle size increased signifi-
cantly, and it causes the increase in the collision probability
between particles and air bubbles in flotation, causing an
enhancement of flotation kinetics.
The results of the agglomeration and batch flotation
tests suggested that the increase in surface hydrophobic-
ity at the conditions of the collector dosage had a signifi-
cant effect on the increasing in the particle size and the
recovery. In flotation, induction time is very important for
the attachment probability between bubbles and particles
(Nguyen and Schulze 2004). Induction time is the time
it takes for a particle to break through the layer of water
between the bubble and the particle and contact with the
bubble (Schulze 1983, Schulze 1989). The mechanism of
agglomeration under the conditions of collector dosage
may also be predicted by evaluating the induction time
between particles and particles.
CONTINUOUS FLOTATION TESTS
Continuous flotation tests were conducted by using a
column flotation cell. Figure 5 (i), (ii), and (iii) show the
effects of collector dosage, pulp density and carrier addition
on the recovery at different residence time. As shown in
Figure 5(i), the recoveries increased with increasing collec-
tor dosage. This agrees with the results of agglomeration test
and batch flotation tests. With a high dosage of collector,
the flotation rate was improved because the particles were
agglomerated and the apparent particle size was increased
at the conditioning stage. Afterward, in the column flota-
tion, because surfaces of the particles are hydrophobic with
the collector addition, they attached to the bubbles and the
recoveries increased.
CONCLUSIONS
The effects of agglomeration on the flotation of a fine cop-
per concentrate were studied. Agglomeration tests, batch
flotation tests, and continuous flotation tests were con-
ducted at various collector dosage, pulp density, and carrier
addition. During the conditioning, apparent particle size
increased significantly by agglomeration, especially when a
high dosage of collector was used. The flotation rate and
recoveries of the batch and continuous flotation tests were
also increased with high collector dosage.
Although copper concentrates were used as the ore
sample in this study, column flotation is usually applied
Figure 3. The batch flotation results of experimental copper recoveries (dot) and fitted curves (line) at the conditions of
collector dosage (i), pulp density (ii), and carrier addition (iii)
Figure 4. The batch flotation results of maximum recovery
R
max and the flotation rate constant k with several collector
dosages
increasing collector dosage, particles became more hydro-
phobic, and this enhance the agglomeration of particles
based on the hydrophobic interaction (Takamori 1985). As
a result, apparent agglomerate particle size increased signifi-
cantly, and it causes the increase in the collision probability
between particles and air bubbles in flotation, causing an
enhancement of flotation kinetics.
The results of the agglomeration and batch flotation
tests suggested that the increase in surface hydrophobic-
ity at the conditions of the collector dosage had a signifi-
cant effect on the increasing in the particle size and the
recovery. In flotation, induction time is very important for
the attachment probability between bubbles and particles
(Nguyen and Schulze 2004). Induction time is the time
it takes for a particle to break through the layer of water
between the bubble and the particle and contact with the
bubble (Schulze 1983, Schulze 1989). The mechanism of
agglomeration under the conditions of collector dosage
may also be predicted by evaluating the induction time
between particles and particles.
CONTINUOUS FLOTATION TESTS
Continuous flotation tests were conducted by using a
column flotation cell. Figure 5 (i), (ii), and (iii) show the
effects of collector dosage, pulp density and carrier addition
on the recovery at different residence time. As shown in
Figure 5(i), the recoveries increased with increasing collec-
tor dosage. This agrees with the results of agglomeration test
and batch flotation tests. With a high dosage of collector,
the flotation rate was improved because the particles were
agglomerated and the apparent particle size was increased
at the conditioning stage. Afterward, in the column flota-
tion, because surfaces of the particles are hydrophobic with
the collector addition, they attached to the bubbles and the
recoveries increased.
CONCLUSIONS
The effects of agglomeration on the flotation of a fine cop-
per concentrate were studied. Agglomeration tests, batch
flotation tests, and continuous flotation tests were con-
ducted at various collector dosage, pulp density, and carrier
addition. During the conditioning, apparent particle size
increased significantly by agglomeration, especially when a
high dosage of collector was used. The flotation rate and
recoveries of the batch and continuous flotation tests were
also increased with high collector dosage.
Although copper concentrates were used as the ore
sample in this study, column flotation is usually applied
Figure 3. The batch flotation results of experimental copper recoveries (dot) and fitted curves (line) at the conditions of
collector dosage (i), pulp density (ii), and carrier addition (iii)
Figure 4. The batch flotation results of maximum recovery
R
max and the flotation rate constant k with several collector
dosages