XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 3647
or for different cleaner stages. If the plant feed sol-
ids flow rate is 100 tph and the rougher concentrate
solids flow rate is 20 tph, then the mass recovery for
rougher is 20%. If the final cleaner concentrate sol-
ids flow rate is 5 tph, then the overall flotation mass
recovery is 5%.
• Concentration ratio (CR): This is the ratio of con-
centrate grade to head grade, also known as the con-
centrate up-grade ratio. In this paper, the head grade
to the flotation plant will be the reference point. If
the head grade is 0.5% Cu and the final rougher con-
centrate grade is 5% Cu, then the CR for rougher
is 10. Now if the rougher concentrate is upgraded
to 25% Cu, then CR for the overall flotation circuit
is 50. Flotation is all about concentration of values,
and this parameter helps to quantify the concentra-
tion not just for rougher cells down-the-bank but
also for various cleaning stages.
• Drop back (DB): This is defined as the percentage of
values, targeted for flotation, lost in the tailings. If
the recovery of the targeted mineral is 90%, then the
drop back is 10%. The aim of any flotation process is
to maximize concentration, depending on the needs
of the downstream processes such as roasting, smelt-
ing or autoclaving, with minimal drop back of values
to tailings.
• Flotation efficiency (FE): Flotation efficiency is
defined as the ratio of cumulative concentration
0
20
40
60
80
100
120
0 5 10 15 20
Survey 1 unsized Survey 1 Size +150 mic
Survey1 Size -150+75 mic Survey1 Size -75+53 mic
Survey1 Size -53+38 mic Survey1 Size -38+20 mic
Survey1 Size -20 mic Bench 7.5 l/min
Bench 10 l/min Bench 12.5 l/min
Bench 15 l/min
Mass Recovery %
0
10
20
30
40
50
60
0 2 4 6 8 10 12 14 16 18
Survey1 unsized Survey 1 Size +150 mic
Survey1 Size -150+75 mic Survey1 Size -75+53 mic
Survey1 Size -53+38 mic Survey1 Size -38+20 mic
Survey1 Size -20 mic Bench 7.5 l/min
Bench 10 l/min Bench 12.5 l/min
Bench 15 l/min
Mass Recovery %
(b)
Figure 2. (a) Relationship between concentration ratio and mass recovery for both bench and plant treating a copper-gold ore
(b) Relationship between drop back and mass recovery in both roughers and cleaners of bench and plant operation treating a
copper-gold ore
Concentrag415onRag415o
DropBack%
or for different cleaner stages. If the plant feed sol-
ids flow rate is 100 tph and the rougher concentrate
solids flow rate is 20 tph, then the mass recovery for
rougher is 20%. If the final cleaner concentrate sol-
ids flow rate is 5 tph, then the overall flotation mass
recovery is 5%.
• Concentration ratio (CR): This is the ratio of con-
centrate grade to head grade, also known as the con-
centrate up-grade ratio. In this paper, the head grade
to the flotation plant will be the reference point. If
the head grade is 0.5% Cu and the final rougher con-
centrate grade is 5% Cu, then the CR for rougher
is 10. Now if the rougher concentrate is upgraded
to 25% Cu, then CR for the overall flotation circuit
is 50. Flotation is all about concentration of values,
and this parameter helps to quantify the concentra-
tion not just for rougher cells down-the-bank but
also for various cleaning stages.
• Drop back (DB): This is defined as the percentage of
values, targeted for flotation, lost in the tailings. If
the recovery of the targeted mineral is 90%, then the
drop back is 10%. The aim of any flotation process is
to maximize concentration, depending on the needs
of the downstream processes such as roasting, smelt-
ing or autoclaving, with minimal drop back of values
to tailings.
• Flotation efficiency (FE): Flotation efficiency is
defined as the ratio of cumulative concentration
0
20
40
60
80
100
120
0 5 10 15 20
Survey 1 unsized Survey 1 Size +150 mic
Survey1 Size -150+75 mic Survey1 Size -75+53 mic
Survey1 Size -53+38 mic Survey1 Size -38+20 mic
Survey1 Size -20 mic Bench 7.5 l/min
Bench 10 l/min Bench 12.5 l/min
Bench 15 l/min
Mass Recovery %
0
10
20
30
40
50
60
0 2 4 6 8 10 12 14 16 18
Survey1 unsized Survey 1 Size +150 mic
Survey1 Size -150+75 mic Survey1 Size -75+53 mic
Survey1 Size -53+38 mic Survey1 Size -38+20 mic
Survey1 Size -20 mic Bench 7.5 l/min
Bench 10 l/min Bench 12.5 l/min
Bench 15 l/min
Mass Recovery %
(b)
Figure 2. (a) Relationship between concentration ratio and mass recovery for both bench and plant treating a copper-gold ore
(b) Relationship between drop back and mass recovery in both roughers and cleaners of bench and plant operation treating a
copper-gold ore
Concentrag415onRag415o
DropBack%