2420 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
a manual rock crusher, a roller mill with two rollers having
a maximum speed of 100 rpm (supplied by Paul O. Abbe
Equipment Company, a division of Aaron Engineered
Process Equipment Inc.), a Denver D12 mechanical flo-
tation cell, an XRF spectrometer (Bruker S2 Puma), a
zeta potential analyzer (Colloidal Dynamics ZetaProbe
Analyzer), a FHD 1080p Action Camera (Kaiser Baas
X230, 60 fps), and a pH meter (Horiba Laqua – pH1300).
EMULSION FORMULATION AND
CHARACTERIZATION
Emulsion formulation was conducted with an oil:water
mass ratio of 1:3. The ratio was selected to create an oil-in-
water emulsion and minimize the oil dosage used in the for-
mulation. A 10 μm emulsion droplet was chosen arbitrarily
because it can deliver a 4 nm thick layer of oil on a 100 µm
diameter particle. The mass of the surfactant required to
form an emulsion with an average size of 10 μm was first
calculated using the properties of the surfactant (such as
the molecular mass and head group area) and kerosene (i.e.,
density 0.8 g/ml). The head group area of the xanthate was
obtained from the literature data (Fornasiero et al., 1995
Liu et al., 2014 Bowden and Young, 2016). The surface
area (Ao) and mass (mo) of a 10 µm oil droplet (Ao) are esti-
mated as shown in Equations 1 and 2 respectively.
Ao =4πro2 =4 × π × 52 =314 (µm)2 (1)
mo =ρ 3
4 πr13 =0.8 × 3
4 × π × 0.00053
=4.19 × 10−10g (2)
Next, the average head group area of xanthate surfac-
tant is 24.1 × 10−8(µm)2. So, the mass (mx) of xanthate
molecules required to cover a 10 µm droplet is calculated
in Equation 3. The molecular weight of potassium amyl
xanthate (PAX) is roughly 202.4 g/mol.
.4
.38
m
24.1 10 6.022 10
314 202
4 10 g
x 23
13
###
#
#
=
=
-8
-
(3)
Thus, the xanthate:oil mass ratio is provided in Equation 4.
.
.38
.00105
m
mo 4 1 019
4 10
0
g
g
g
g
x
13
#
#
==
-10
-
(4)
Based on this mass ratio, 0.105 g of PAX was dissolved in
300 g of water and allowed to dissolve completely. This was
followed by the addition of 100 g of kerosene. Then, the
mixture was homogenized with the high-speed mixer, and
emulsion characteristics (such as droplet size, zeta poten-
tial, rate of creaming, and oil separation) were investigated.
The characterization of the emulsion was conducted with
the standard procedures recommended by the equipment
manufacturers. The size distribution was measured with
the Malvern Mastersizer 3000. The system was cleaned
three times with water. Then, a clean beaker was filled with
500 mL of RO water, and the material optical properties
(i.e., density and refractive index) as well as those of the
dispersant were input into the system. The density of 0.8 g/
cm3 and refractive index of 1.44 were used for kerosene
while 2.77 g/cm3 and 1.53 were used for the ore sample.
Afterward, the background was measured, and a few
drops of the emulsion were added to have an obscura-
tion of slightly above 1%. Then, the size distribution was
measured five times, and the average value was recorded.
The zeta potential and conductivity of the emulsion were
measured with a Colloidal Dynamics ZetaProbe Analyzer.
The system was calibrated with 300 mL standard solution
(0.25 S/m KSiW). The pH probe of the analyzer was also
calibrated with the buffer solutions (pH values of 4, 7,
and 10). Afterward, the system was cleaned and filled with
300 mL emulsion, and the magnetic stirrer was turned on.
Subsequently, the solvent and material properties (such as
density, concentration, and dielectric constant) were added
to the system. The zeta potential was measured three times,
and the average value was recorded.
The rate of creaming and oil separation from the
emulsion were studied with the Kaiser Baas X230 camera.
Within 2 min after the emulsion formulation, approxi-
mately 360 mL of the emulsion was poured into a 500 mL
graduated cylinder up to 20 cm high and allowed to rest
undisturbed in ambient conditions for 100 h. The recorded
images of the emulsion over this period were used to esti-
mate the oil separation as the height of the separated oil at
the top of the column. Next, the cream height was deter-
mined as the difference between the heights of the separated
oil above the cream and the water column below the cream.
MINERAL SAMPLING AND GRIND
CALIBRATION STUDY
The ore sample was initially crushed with a manual rock
crusher and passed through a 2 mm sieve. Then, a riffle
splitter was used to split the feed sample of 6,400 g into
representative samples. A total of 32 samples (approxi-
mately 200 g each) were obtained from the process.
A grind calibration study was conducted after mineral
sampling. Initially, the density of the feed ore sample was
estimated as 2.77 g/cm3 with Archimedes’ principle. Then,
theoretical calculations were carried out to determine the
sample mass, ball size, and rotational speed required for a 2
L mill jar and the roller mills. The assumptions of 40%
a manual rock crusher, a roller mill with two rollers having
a maximum speed of 100 rpm (supplied by Paul O. Abbe
Equipment Company, a division of Aaron Engineered
Process Equipment Inc.), a Denver D12 mechanical flo-
tation cell, an XRF spectrometer (Bruker S2 Puma), a
zeta potential analyzer (Colloidal Dynamics ZetaProbe
Analyzer), a FHD 1080p Action Camera (Kaiser Baas
X230, 60 fps), and a pH meter (Horiba Laqua – pH1300).
EMULSION FORMULATION AND
CHARACTERIZATION
Emulsion formulation was conducted with an oil:water
mass ratio of 1:3. The ratio was selected to create an oil-in-
water emulsion and minimize the oil dosage used in the for-
mulation. A 10 μm emulsion droplet was chosen arbitrarily
because it can deliver a 4 nm thick layer of oil on a 100 µm
diameter particle. The mass of the surfactant required to
form an emulsion with an average size of 10 μm was first
calculated using the properties of the surfactant (such as
the molecular mass and head group area) and kerosene (i.e.,
density 0.8 g/ml). The head group area of the xanthate was
obtained from the literature data (Fornasiero et al., 1995
Liu et al., 2014 Bowden and Young, 2016). The surface
area (Ao) and mass (mo) of a 10 µm oil droplet (Ao) are esti-
mated as shown in Equations 1 and 2 respectively.
Ao =4πro2 =4 × π × 52 =314 (µm)2 (1)
mo =ρ 3
4 πr13 =0.8 × 3
4 × π × 0.00053
=4.19 × 10−10g (2)
Next, the average head group area of xanthate surfac-
tant is 24.1 × 10−8(µm)2. So, the mass (mx) of xanthate
molecules required to cover a 10 µm droplet is calculated
in Equation 3. The molecular weight of potassium amyl
xanthate (PAX) is roughly 202.4 g/mol.
.4
.38
m
24.1 10 6.022 10
314 202
4 10 g
x 23
13
###
#
#
=
=
-8
-
(3)
Thus, the xanthate:oil mass ratio is provided in Equation 4.
.
.38
.00105
m
mo 4 1 019
4 10
0
g
g
g
g
x
13
#
#
==
-10
-
(4)
Based on this mass ratio, 0.105 g of PAX was dissolved in
300 g of water and allowed to dissolve completely. This was
followed by the addition of 100 g of kerosene. Then, the
mixture was homogenized with the high-speed mixer, and
emulsion characteristics (such as droplet size, zeta poten-
tial, rate of creaming, and oil separation) were investigated.
The characterization of the emulsion was conducted with
the standard procedures recommended by the equipment
manufacturers. The size distribution was measured with
the Malvern Mastersizer 3000. The system was cleaned
three times with water. Then, a clean beaker was filled with
500 mL of RO water, and the material optical properties
(i.e., density and refractive index) as well as those of the
dispersant were input into the system. The density of 0.8 g/
cm3 and refractive index of 1.44 were used for kerosene
while 2.77 g/cm3 and 1.53 were used for the ore sample.
Afterward, the background was measured, and a few
drops of the emulsion were added to have an obscura-
tion of slightly above 1%. Then, the size distribution was
measured five times, and the average value was recorded.
The zeta potential and conductivity of the emulsion were
measured with a Colloidal Dynamics ZetaProbe Analyzer.
The system was calibrated with 300 mL standard solution
(0.25 S/m KSiW). The pH probe of the analyzer was also
calibrated with the buffer solutions (pH values of 4, 7,
and 10). Afterward, the system was cleaned and filled with
300 mL emulsion, and the magnetic stirrer was turned on.
Subsequently, the solvent and material properties (such as
density, concentration, and dielectric constant) were added
to the system. The zeta potential was measured three times,
and the average value was recorded.
The rate of creaming and oil separation from the
emulsion were studied with the Kaiser Baas X230 camera.
Within 2 min after the emulsion formulation, approxi-
mately 360 mL of the emulsion was poured into a 500 mL
graduated cylinder up to 20 cm high and allowed to rest
undisturbed in ambient conditions for 100 h. The recorded
images of the emulsion over this period were used to esti-
mate the oil separation as the height of the separated oil at
the top of the column. Next, the cream height was deter-
mined as the difference between the heights of the separated
oil above the cream and the water column below the cream.
MINERAL SAMPLING AND GRIND
CALIBRATION STUDY
The ore sample was initially crushed with a manual rock
crusher and passed through a 2 mm sieve. Then, a riffle
splitter was used to split the feed sample of 6,400 g into
representative samples. A total of 32 samples (approxi-
mately 200 g each) were obtained from the process.
A grind calibration study was conducted after mineral
sampling. Initially, the density of the feed ore sample was
estimated as 2.77 g/cm3 with Archimedes’ principle. Then,
theoretical calculations were carried out to determine the
sample mass, ball size, and rotational speed required for a 2
L mill jar and the roller mills. The assumptions of 40%