XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 2187
on a large scale (Gray et al., 1990). Laterite nickel ores
are extensively exploited, and the recent nickel boom has
been almost solely off the back of laterites. The nickel sul-
fide ore is currently the most used type of nickel resource,
accounting for 59% of the world’s nickel production. The
world’s basic nickel reserves amount to 14 billion tonnes,
with nickel sulfide ore resources accounting for only 30%.
Despite this, nickel sulfide ore resources are highly sought-
after due to their superior quality and mature process tech-
nology (Sharma, 2011).
Froth flotation is a water-intensive physiochemical sep-
aration process widely employed in the minerals processing
field, usually requiring a substantial amount of fresh water.
Due to the scarcity of fresh water, many flotation operations
utilize recycled water, underground water, saline water, or
seawater as a sustainable alternative (Peng and Seaman,
2011). The widely observed increase in flotation recovery
with using saline water replacing fresh water is linked to
improved gas dispersion and bubble coalescence inhibi-
tion associated with decreased bubble size, and increased
foam/froth stability (Dong and Wang, 2023). However, the
cations and ions in the saline water may also do harm to
the separation process when the classification and/or con-
centration are not proper (Peng et al., 2011). Considering
that the chemical formula of pentlandite is (Fe,Ni)9S8 and
serpentine is Mg3Si2O5(OH)4, it is expected that the fol-
lowing ions are also available in solutions Mg2+, Fe2+, and
Ni2+. This is very important considering that a small dis-
solution of various minerals was observed, leading to the
formation of different ions in solutions and thus activation
of mineral surfaces during flotation.
In this work, the influence of divalent cations on
the flotation of pentlandite and lizardite is investigated.
Additionally, characterizations of minerals (pentlandite and
lizardite) are introduced, such as X-ray diffraction (XRD)
analysis of original minerals to see the minerology of miner-
als. A new microflotation column was prepared, and suitable
experimental parameters were explored. To characterize the
influence of divalent cations on the flotation performance,
zeta potential measurement, ultraviolet-visible (UV-vis)
analysis, and micro floatation tests were carried out.
MATERIALS AND METHODOLOGY
Materials
Chemicals
Different chemical reagents were used in this work, such as
frother, collector, and activator, which are listed in Table 1,
including their chemical names, formula, suppliers, and
purities. Methyl isobutyl carbinol (MIBC) frother with
concentrations of 20, 30 and 40 ppm were prepared for
use. Sodium ethyl xanthate (SEX) collector solution with
a molar concentration of 2 × 10–4 mol/L was prepared and
used as collector for the microflotation experiments (Huang
and Zhang, 2019). The CuSO4 solution with a concentra-
tion of 1 wt.% was prepared for further use as an activator.
The deionised water with a resistivity of 18.2 MΩ·cm was
used for all the experiments. The electrolytes and deionised
water were mixed to produce electrolyte solutions with dif-
ferent molar concentrations, such as 0.001, 0.01, 0.1 and
1 mol/L.
Minerals
The nickel sulfide ore rock was collected from the Cliffs mine
site of BHP Nickel West in Western Australia, Australia,
and its main mineral is pentlandite ((Fe,Ni)9S8). The lizard-
ite was mined from Norway, Europe, and its main mineral is
Mg3Si2O5(OH)4. The ore rock samples were crushed firstly
using a jaw crusher EB 50×40-L (Siebtechnick GmbH,
Mülheim, Germany), then a roll crusher (Vickers Ruwolt
Pty. Ltd). After that the collected small rock pieces were
ground using the pulveriser (Rocklabs Limited, Auckland,
New Zealand) for one minute each time. The collected
mineral particles were screened with different aperture
sizes (e.g., 38 and 75 um) and an electric shaker Ro-Tap ®
Testing Sieve Shaker Model B (W.S. Tyler, Incorporated
Table 1. Functional chemical reagents used in the present work
Functional
Reagents Chemical Name and Formula Supplier Purity (%)
Medium Deionised water Milli-Q® (Millipore, USA) 100
Frother Methyl isobutyl carbinol (MIBC) Rowe Scientific ≥98
Collector Sodium ethyl xanthate (SEX) Chem-supply ≥98
Activator Copper sulphate pentahydrate (CuSO
4 ·5H
2 O) Sigma-Aldrich, Australia ≥98
Electrolytes Calcium chloride dihydrate (CaCl
2 ·2H
2 O) Thermo Fisher Scientific ≥99
Magnesium chloride hexahydrate (MgCl2·6H2O) Chem-supply ≥99
Nickel chloride hexahydrate (NiCl2·6H2O) Chem-supply ≥98
Ferrous chloride tetrahydrate (FeCl
2 ·4H
2 O) Sigma-Aldrich, Australia ≥98
on a large scale (Gray et al., 1990). Laterite nickel ores
are extensively exploited, and the recent nickel boom has
been almost solely off the back of laterites. The nickel sul-
fide ore is currently the most used type of nickel resource,
accounting for 59% of the world’s nickel production. The
world’s basic nickel reserves amount to 14 billion tonnes,
with nickel sulfide ore resources accounting for only 30%.
Despite this, nickel sulfide ore resources are highly sought-
after due to their superior quality and mature process tech-
nology (Sharma, 2011).
Froth flotation is a water-intensive physiochemical sep-
aration process widely employed in the minerals processing
field, usually requiring a substantial amount of fresh water.
Due to the scarcity of fresh water, many flotation operations
utilize recycled water, underground water, saline water, or
seawater as a sustainable alternative (Peng and Seaman,
2011). The widely observed increase in flotation recovery
with using saline water replacing fresh water is linked to
improved gas dispersion and bubble coalescence inhibi-
tion associated with decreased bubble size, and increased
foam/froth stability (Dong and Wang, 2023). However, the
cations and ions in the saline water may also do harm to
the separation process when the classification and/or con-
centration are not proper (Peng et al., 2011). Considering
that the chemical formula of pentlandite is (Fe,Ni)9S8 and
serpentine is Mg3Si2O5(OH)4, it is expected that the fol-
lowing ions are also available in solutions Mg2+, Fe2+, and
Ni2+. This is very important considering that a small dis-
solution of various minerals was observed, leading to the
formation of different ions in solutions and thus activation
of mineral surfaces during flotation.
In this work, the influence of divalent cations on
the flotation of pentlandite and lizardite is investigated.
Additionally, characterizations of minerals (pentlandite and
lizardite) are introduced, such as X-ray diffraction (XRD)
analysis of original minerals to see the minerology of miner-
als. A new microflotation column was prepared, and suitable
experimental parameters were explored. To characterize the
influence of divalent cations on the flotation performance,
zeta potential measurement, ultraviolet-visible (UV-vis)
analysis, and micro floatation tests were carried out.
MATERIALS AND METHODOLOGY
Materials
Chemicals
Different chemical reagents were used in this work, such as
frother, collector, and activator, which are listed in Table 1,
including their chemical names, formula, suppliers, and
purities. Methyl isobutyl carbinol (MIBC) frother with
concentrations of 20, 30 and 40 ppm were prepared for
use. Sodium ethyl xanthate (SEX) collector solution with
a molar concentration of 2 × 10–4 mol/L was prepared and
used as collector for the microflotation experiments (Huang
and Zhang, 2019). The CuSO4 solution with a concentra-
tion of 1 wt.% was prepared for further use as an activator.
The deionised water with a resistivity of 18.2 MΩ·cm was
used for all the experiments. The electrolytes and deionised
water were mixed to produce electrolyte solutions with dif-
ferent molar concentrations, such as 0.001, 0.01, 0.1 and
1 mol/L.
Minerals
The nickel sulfide ore rock was collected from the Cliffs mine
site of BHP Nickel West in Western Australia, Australia,
and its main mineral is pentlandite ((Fe,Ni)9S8). The lizard-
ite was mined from Norway, Europe, and its main mineral is
Mg3Si2O5(OH)4. The ore rock samples were crushed firstly
using a jaw crusher EB 50×40-L (Siebtechnick GmbH,
Mülheim, Germany), then a roll crusher (Vickers Ruwolt
Pty. Ltd). After that the collected small rock pieces were
ground using the pulveriser (Rocklabs Limited, Auckland,
New Zealand) for one minute each time. The collected
mineral particles were screened with different aperture
sizes (e.g., 38 and 75 um) and an electric shaker Ro-Tap ®
Testing Sieve Shaker Model B (W.S. Tyler, Incorporated
Table 1. Functional chemical reagents used in the present work
Functional
Reagents Chemical Name and Formula Supplier Purity (%)
Medium Deionised water Milli-Q® (Millipore, USA) 100
Frother Methyl isobutyl carbinol (MIBC) Rowe Scientific ≥98
Collector Sodium ethyl xanthate (SEX) Chem-supply ≥98
Activator Copper sulphate pentahydrate (CuSO
4 ·5H
2 O) Sigma-Aldrich, Australia ≥98
Electrolytes Calcium chloride dihydrate (CaCl
2 ·2H
2 O) Thermo Fisher Scientific ≥99
Magnesium chloride hexahydrate (MgCl2·6H2O) Chem-supply ≥99
Nickel chloride hexahydrate (NiCl2·6H2O) Chem-supply ≥98
Ferrous chloride tetrahydrate (FeCl
2 ·4H
2 O) Sigma-Aldrich, Australia ≥98