XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 2519
weight (Echeverry et al. 2021/2022 Estrada 2020). PAM
can significantly inhibit flotation through alterations to the
interfacial characteristics of the solid/liquid and liquid/gas
interfaces (Moudgil, 1983). It was previously reported that
modified PAMs (hydroxamic, carboxylated, sulfonated,
hydroxylated, and modified by xanthation) can interact
with pyrite through chemical bonding and depress its flo-
tation (Zhang et al., 2004 Boulton et al., 2001 Wang et
al., 2012). It was also reported that cationic PAMs can be
used as depressants to separate kaolinite and diaspore using
flotation with dodecyl amine as collector (Liu et al., 2007).
It was also shown that anionic PAMs of degrees of anionic-
ity of 8.15 and 11.9% depress molybdenite flotation under
varying physicochemical environments and low mechanical
degradation (Echeverry et al., 2021 Estrada et al., 2020).
Studies on the effect of anionic PAMs on the flotation
of relevant copper sulfides such as bornite, enargite and
chalcopyrite are scarce. In this work, results on the effect
of an anionic PAM of medium-low anionicity on the flota-
tion of chalcopyrite, enargite, and bornite are reported and
analyzed.
METHODOLOGY
Materials and Reagents
The enargite mineral sample was acquired from the
Quiruvilca mine in Perú, and chalcopyrite and bornite
were provided by Ward´s Natural Science Establishment.
The samples were initially crushed by hand grinding to a
size range of –2 +1.4 mm, and then manually concentrated
to remove visually evident impurities. Later, a magnetic
separator was used to remove magnetic minerals, and des-
liming (–600#) was applied to remove ultra-fines. X-ray
diffraction (XRD) using Bruker ® D4 Endeavor equipment
with Cu radiation and Ni Kβ radiation filter was used to
analyze the minerals. XRD analyses indicate that enargite,
chalcopyrite, and bornite samples were 99.8%, 99.5%,
and 99.7% purity respectively. Enargite contained minor
amounts of tennantite, while the chalcopyrite and bornite
samples reported low concentrations of pyrite and quartz.
The carboxylated PAM tested in the study was obtained
from SNF-Chile (99.99% as indicated by the company)
and was identified as SNF2350. The PAM was presented
in dry white granules and was tested in the study with no
treatment and/or purification. The provider indicated that
the PAM flocculant was anionic in nature and of molecular
weight of around 16 × 106 Da. Previous characterization of
the same PAM sample reported a DA of 11.9%.
Potassium amyl xanthate (PAX from Solvay) purified
using ether and acetone was used as collector, and methyl
isobutyl carbinol (MIBC) from Merck as frother. Milli-Q
water of a resistivity of 18.4 MΩ∙cm at 25 °C was used in
all the experiments. pH was adjusted with sodium hydrox-
ide (NaOH). The aqueous medium for the experiments was
a 0.01 M NaCl.
Procedure
Microflotation
Mineral flotation was evaluated through microflotation
experiments conducted in a 150 mL Partridge and Smith
glass cell following the procedure described in Figure 1.
Initially, the copper sulfides in the –2 +1.4 mm size fraction
were wet ground using a lab carbon steel ball mill (7 cm
diameter and 12 cm length) charged with 270 g of carbon
steel balls (12 balls of 13 mm diameter 8 balls of 17 mm
diameter). The micro-flotation experiments considered
3 grams of the mineral samples previously ground to a P80
NaOH
PAX
MIBC
Conditioning
t=2 min
Mineral
0,01M NaCl
Aqueous
solution
P80=
74 μm
t=2 min
N
2 ,80 mL/min
Concentrate
Wet
Grinding Volume
150 mL
Pulp
Partridge
Smith glass
cell
Conditioning
t=2 min
PAM
Conditioning
t=2 min
Tailing
Figure 1. Microflotation procedure
weight (Echeverry et al. 2021/2022 Estrada 2020). PAM
can significantly inhibit flotation through alterations to the
interfacial characteristics of the solid/liquid and liquid/gas
interfaces (Moudgil, 1983). It was previously reported that
modified PAMs (hydroxamic, carboxylated, sulfonated,
hydroxylated, and modified by xanthation) can interact
with pyrite through chemical bonding and depress its flo-
tation (Zhang et al., 2004 Boulton et al., 2001 Wang et
al., 2012). It was also reported that cationic PAMs can be
used as depressants to separate kaolinite and diaspore using
flotation with dodecyl amine as collector (Liu et al., 2007).
It was also shown that anionic PAMs of degrees of anionic-
ity of 8.15 and 11.9% depress molybdenite flotation under
varying physicochemical environments and low mechanical
degradation (Echeverry et al., 2021 Estrada et al., 2020).
Studies on the effect of anionic PAMs on the flotation
of relevant copper sulfides such as bornite, enargite and
chalcopyrite are scarce. In this work, results on the effect
of an anionic PAM of medium-low anionicity on the flota-
tion of chalcopyrite, enargite, and bornite are reported and
analyzed.
METHODOLOGY
Materials and Reagents
The enargite mineral sample was acquired from the
Quiruvilca mine in Perú, and chalcopyrite and bornite
were provided by Ward´s Natural Science Establishment.
The samples were initially crushed by hand grinding to a
size range of –2 +1.4 mm, and then manually concentrated
to remove visually evident impurities. Later, a magnetic
separator was used to remove magnetic minerals, and des-
liming (–600#) was applied to remove ultra-fines. X-ray
diffraction (XRD) using Bruker ® D4 Endeavor equipment
with Cu radiation and Ni Kβ radiation filter was used to
analyze the minerals. XRD analyses indicate that enargite,
chalcopyrite, and bornite samples were 99.8%, 99.5%,
and 99.7% purity respectively. Enargite contained minor
amounts of tennantite, while the chalcopyrite and bornite
samples reported low concentrations of pyrite and quartz.
The carboxylated PAM tested in the study was obtained
from SNF-Chile (99.99% as indicated by the company)
and was identified as SNF2350. The PAM was presented
in dry white granules and was tested in the study with no
treatment and/or purification. The provider indicated that
the PAM flocculant was anionic in nature and of molecular
weight of around 16 × 106 Da. Previous characterization of
the same PAM sample reported a DA of 11.9%.
Potassium amyl xanthate (PAX from Solvay) purified
using ether and acetone was used as collector, and methyl
isobutyl carbinol (MIBC) from Merck as frother. Milli-Q
water of a resistivity of 18.4 MΩ∙cm at 25 °C was used in
all the experiments. pH was adjusted with sodium hydrox-
ide (NaOH). The aqueous medium for the experiments was
a 0.01 M NaCl.
Procedure
Microflotation
Mineral flotation was evaluated through microflotation
experiments conducted in a 150 mL Partridge and Smith
glass cell following the procedure described in Figure 1.
Initially, the copper sulfides in the –2 +1.4 mm size fraction
were wet ground using a lab carbon steel ball mill (7 cm
diameter and 12 cm length) charged with 270 g of carbon
steel balls (12 balls of 13 mm diameter 8 balls of 17 mm
diameter). The micro-flotation experiments considered
3 grams of the mineral samples previously ground to a P80
NaOH
PAX
MIBC
Conditioning
t=2 min
Mineral
0,01M NaCl
Aqueous
solution
P80=
74 μm
t=2 min
N
2 ,80 mL/min
Concentrate
Wet
Grinding Volume
150 mL
Pulp
Partridge
Smith glass
cell
Conditioning
t=2 min
PAM
Conditioning
t=2 min
Tailing
Figure 1. Microflotation procedure