XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 2189
cos
K
$x b i =m (2)
Zeta Potential Measurement
Zeta potential measurements will also be determined to
analyse charge of mineral particles and thus determine
adsorption properties on mineral surfaces to better under-
stand the flotation mechanisms. The collected mineral par-
ticles with a particle size range of – 38 µm are used for the
zeta potential analysis. Those mineral particles are further
ground using a mortar and pestle and screened through
25 μm sieve to collect the undersized fraction. 0.01 g
mineral particles were added to 20 µL CuSO4 solution
(1 wt.%), SEX solution (0.2 mol/L), and MIBC solution
(3 g/L) 20 mL HCl solutions with pHs of 3 or 5, or NaOH
solutions with pHs of 9 or 11, or deionised water (treated
as pH neutral solution), or electrolyte solutions with dif-
ferent electrolyte molar concentrations. The final suspen-
sion with an approximate solid concentration of 0.05%
was used for the zeta potential measurements. Before zeta
potential experiments, the suspension samples are stirred
and conditioned for 3 min. The conditioning procedure is
similar to the microflotation experiments. After condition-
ing, large particles were allowed to settle down from the
suspension. Then, the supernatant solution was collected
and transferred to a zeta potential measurement cell via a 1
mL syringe. The analysis for each suspension sample were
conducted in six runs, four results were recorded, the mean
was reported with the error bars.
UV-vis Analysis
UV-vis analysis can be used to understand the adsorption
of SEX in the presence of different solutions. The collected
mineral particles with a particle size range of +38–75 µm
are used for the zeta potential analysis. In this analysis,
frother was not added, which was supposed not to influence
the collector adsorption by minerals based on the previous
work (Zhou et al., 2019). The suspensions are stirred for
1800 s to ensure adsorption equilibrium, then filtrated, and
the concentration of residual collector is measured by the
PerkinElmer UV/VIS Spectrometer Lambda 35 equipment
(PerkinElmer, Inc., USA). The wavelength ranges from 700
to 200 nm during all measurements. The collector adsorp-
tion capacity on the surface of minerals is calculated using
Equation 3:
(
m
C C) V
0 #
C =
-
(3)
where Γ is the collector adsorption capacity on the surface
of minerals (mol/g), C0 is the initial concentration of col-
lector in slurry (mol/L), C is the residual concentration of
collector in slurry (mol/L), V is the slurry volume (L), m is
the mass of sample (g).
Since experiments are conducted in the saline water,
following cations need to be considered: Ca2+, Mg2+,
Fe2+, Ni2+, Na+, and K+. Although Na+, K+ may adsorb
on mineral surfaces but they cannot bind to sulphur atom
in xanthate or other atoms in the suspension with a col-
lector and thus activate more mineral particles. The reason
is that these ions are missing one electron only, i.e., these
100 200 300 400 500
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
Air flowrate (mL/min)
Deionised water
MIBC 20 ppm
MIBC 30 ppm
MIBC 40 ppm
(a)
100 200 300 400 500
−20
0
20
40
60
80
100
120
Air flowrate (mL/min)
0-20 ppm/Total
20-30 ppm/Total
30-40 ppm/Total
(b)
Figure 2. (a) Gas holdup measurement of deionised water and MIBC solutions with different concentrations under different
air flowrates. (b) The percentage of the gas holdup increment occupies the total gas holdup increment from with deionised
water to with MIBC with a concentration of 40 ppm
Gas
holdup
(Percentage*102)
Gas
holdup
increment/Total
(%)
cos
K
$x b i =m (2)
Zeta Potential Measurement
Zeta potential measurements will also be determined to
analyse charge of mineral particles and thus determine
adsorption properties on mineral surfaces to better under-
stand the flotation mechanisms. The collected mineral par-
ticles with a particle size range of – 38 µm are used for the
zeta potential analysis. Those mineral particles are further
ground using a mortar and pestle and screened through
25 μm sieve to collect the undersized fraction. 0.01 g
mineral particles were added to 20 µL CuSO4 solution
(1 wt.%), SEX solution (0.2 mol/L), and MIBC solution
(3 g/L) 20 mL HCl solutions with pHs of 3 or 5, or NaOH
solutions with pHs of 9 or 11, or deionised water (treated
as pH neutral solution), or electrolyte solutions with dif-
ferent electrolyte molar concentrations. The final suspen-
sion with an approximate solid concentration of 0.05%
was used for the zeta potential measurements. Before zeta
potential experiments, the suspension samples are stirred
and conditioned for 3 min. The conditioning procedure is
similar to the microflotation experiments. After condition-
ing, large particles were allowed to settle down from the
suspension. Then, the supernatant solution was collected
and transferred to a zeta potential measurement cell via a 1
mL syringe. The analysis for each suspension sample were
conducted in six runs, four results were recorded, the mean
was reported with the error bars.
UV-vis Analysis
UV-vis analysis can be used to understand the adsorption
of SEX in the presence of different solutions. The collected
mineral particles with a particle size range of +38–75 µm
are used for the zeta potential analysis. In this analysis,
frother was not added, which was supposed not to influence
the collector adsorption by minerals based on the previous
work (Zhou et al., 2019). The suspensions are stirred for
1800 s to ensure adsorption equilibrium, then filtrated, and
the concentration of residual collector is measured by the
PerkinElmer UV/VIS Spectrometer Lambda 35 equipment
(PerkinElmer, Inc., USA). The wavelength ranges from 700
to 200 nm during all measurements. The collector adsorp-
tion capacity on the surface of minerals is calculated using
Equation 3:
(
m
C C) V
0 #
C =
-
(3)
where Γ is the collector adsorption capacity on the surface
of minerals (mol/g), C0 is the initial concentration of col-
lector in slurry (mol/L), C is the residual concentration of
collector in slurry (mol/L), V is the slurry volume (L), m is
the mass of sample (g).
Since experiments are conducted in the saline water,
following cations need to be considered: Ca2+, Mg2+,
Fe2+, Ni2+, Na+, and K+. Although Na+, K+ may adsorb
on mineral surfaces but they cannot bind to sulphur atom
in xanthate or other atoms in the suspension with a col-
lector and thus activate more mineral particles. The reason
is that these ions are missing one electron only, i.e., these
100 200 300 400 500
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
Air flowrate (mL/min)
Deionised water
MIBC 20 ppm
MIBC 30 ppm
MIBC 40 ppm
(a)
100 200 300 400 500
−20
0
20
40
60
80
100
120
Air flowrate (mL/min)
0-20 ppm/Total
20-30 ppm/Total
30-40 ppm/Total
(b)
Figure 2. (a) Gas holdup measurement of deionised water and MIBC solutions with different concentrations under different
air flowrates. (b) The percentage of the gas holdup increment occupies the total gas holdup increment from with deionised
water to with MIBC with a concentration of 40 ppm
Gas
holdup
(Percentage*102)
Gas
holdup
increment/Total
(%)