XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 2191
Diffraction Data (ICDD) and previous relevant literature
(Konkena et al., 2016 Liu et al., 2019 Liu et al., 2022
Nkoma and Ekosse, 1999 Yuan et al., 2017). Pentlandite,
including pyrrhotite, talc, FeS, pyroxene and pyrite are
identified in the pentlandite mineral sample, while lizardite
and antigorite ((Mg2+, Fe2+)3Si2O5(OH)4) are recognised
in the lizardite mineral sample (Liu et al., 2019 Lu et al.,
2017 Pereira et al., 2007 Zhang et al., 2019).
Microflotation Performance
Cumulative recoveries of microflotation of mineral samples
generated under pH neutral experimental conditions in
the absence/presence of CuSO4 are displayed in Figure 4,
and the error bar stands for a standard error of the mean
generated from two independent runs. As can be seen
from Figure 4, with the CuSO4 used as the activator, both
cumulative recoveries of pentlandite and lizardite increased
with the recovery of pentlandite increasing from 37.02 to
73.34%, and the recovery of lizardite increasing from 4.25
to 8.41%. The addition of activator CuSO4 further increase
flotation recoveries of both pentlandite and serpentine, this
was also verified by other researchers (Bao et al., 2018
Fornasiero and Ralston, 2005 Huang and Zhang, 2019).
Influence of pH
The recoveries of microflotation of mineral samples gen-
erated from experimental conditions in the presence of
CuSO4 at different pH values are displayed in Figure 5 (a),
while the selectivity indexes under the sample experimental
conditions are displayed in Figure 5 (b).
According to Millican and Sauers (Millican and Sauers,
1979), SEX easily adsorbs on the surface of sulfide miner-
als, the aqueous solution of SEX is stable at high pH if
not heated. It rapidly hydrolyses at pH less than 9 at 25
°C as shown in Equation 5. It is the conjugate base of the
ethyl xanthic acid, a strong acid with pKa of 1.6 and pKb
estimated as 12.4 for the conjugate base. It is susceptible to
oxidation at low pH as well as shown in Equation 6.
C2H5OCS2Na +H+ → C2H5OH +CS2 +Na+ (5)
10 20 30 40 50
0
200
400
600
800
1000
1200
1400
2θ (°)
F -FeS
H -Pyrrhotite
P -Pentlandite
T -Talc
X -Pyroxene
Y -Pyrite
P
P
P
P
P
P
P
H
T
Y
H
Y
H
Y
H
X
Y
F
H
F
H
P
X
F
F
H T
T T T
T
X
P
(a)
10 20 30 40 50
0
300
600
900
1200
1500
1800
2100
2400
2700
3000
2θ (°)
A -Antigorite
L -Lizardite
L
L
L
L
L
L A
L
L
L
L
A
A
A
A
A
(b)
Figure 3. XRD patterns of pentlandite mineral sample (a) and lizardite mineral sample (b) in the particle size range of 38 –
75 µm
0 2 4 6 8 10
0
10
20
30
40
50
60
70
80
90
Time (min)
Pentlandite Lizardite
Without CuSO
4
With CuSO4
Figure 4. Cumulative recoveries of micro floatation of
mineral samples in the absence/presence of CuSO4 under a
pH neutral experimental condition. The error bar stands for
a standard error of the mean of two independent runs
Intensity
(Counts)
Intensity
(Counts)
Cumulative
Recovery
(%)
Diffraction Data (ICDD) and previous relevant literature
(Konkena et al., 2016 Liu et al., 2019 Liu et al., 2022
Nkoma and Ekosse, 1999 Yuan et al., 2017). Pentlandite,
including pyrrhotite, talc, FeS, pyroxene and pyrite are
identified in the pentlandite mineral sample, while lizardite
and antigorite ((Mg2+, Fe2+)3Si2O5(OH)4) are recognised
in the lizardite mineral sample (Liu et al., 2019 Lu et al.,
2017 Pereira et al., 2007 Zhang et al., 2019).
Microflotation Performance
Cumulative recoveries of microflotation of mineral samples
generated under pH neutral experimental conditions in
the absence/presence of CuSO4 are displayed in Figure 4,
and the error bar stands for a standard error of the mean
generated from two independent runs. As can be seen
from Figure 4, with the CuSO4 used as the activator, both
cumulative recoveries of pentlandite and lizardite increased
with the recovery of pentlandite increasing from 37.02 to
73.34%, and the recovery of lizardite increasing from 4.25
to 8.41%. The addition of activator CuSO4 further increase
flotation recoveries of both pentlandite and serpentine, this
was also verified by other researchers (Bao et al., 2018
Fornasiero and Ralston, 2005 Huang and Zhang, 2019).
Influence of pH
The recoveries of microflotation of mineral samples gen-
erated from experimental conditions in the presence of
CuSO4 at different pH values are displayed in Figure 5 (a),
while the selectivity indexes under the sample experimental
conditions are displayed in Figure 5 (b).
According to Millican and Sauers (Millican and Sauers,
1979), SEX easily adsorbs on the surface of sulfide miner-
als, the aqueous solution of SEX is stable at high pH if
not heated. It rapidly hydrolyses at pH less than 9 at 25
°C as shown in Equation 5. It is the conjugate base of the
ethyl xanthic acid, a strong acid with pKa of 1.6 and pKb
estimated as 12.4 for the conjugate base. It is susceptible to
oxidation at low pH as well as shown in Equation 6.
C2H5OCS2Na +H+ → C2H5OH +CS2 +Na+ (5)
10 20 30 40 50
0
200
400
600
800
1000
1200
1400
2θ (°)
F -FeS
H -Pyrrhotite
P -Pentlandite
T -Talc
X -Pyroxene
Y -Pyrite
P
P
P
P
P
P
P
H
T
Y
H
Y
H
Y
H
X
Y
F
H
F
H
P
X
F
F
H T
T T T
T
X
P
(a)
10 20 30 40 50
0
300
600
900
1200
1500
1800
2100
2400
2700
3000
2θ (°)
A -Antigorite
L -Lizardite
L
L
L
L
L
L A
L
L
L
L
A
A
A
A
A
(b)
Figure 3. XRD patterns of pentlandite mineral sample (a) and lizardite mineral sample (b) in the particle size range of 38 –
75 µm
0 2 4 6 8 10
0
10
20
30
40
50
60
70
80
90
Time (min)
Pentlandite Lizardite
Without CuSO
4
With CuSO4
Figure 4. Cumulative recoveries of micro floatation of
mineral samples in the absence/presence of CuSO4 under a
pH neutral experimental condition. The error bar stands for
a standard error of the mean of two independent runs
Intensity
(Counts)
Intensity
(Counts)
Cumulative
Recovery
(%)