XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 3325
similarities of associated pegmatite minerals such as quartz,
feldspar, and mica (Gibson et al., 2017). Therefore, devel-
oping comprehensive enrichment schemes that combine
multiple processing methods is essential to efficiently sepa-
rate and extract valuable minerals from complex ores.
In Kazakhstan, there has been significant exploration
and development of lithium-bearing deposits and tailings.
Preliminary estimates indicate promising lithium reserves
in six locations in Eastern Kazakhstan: Yubileynoye,
Akhmetkino, Bakkennoye, Verkhne-Baymurzinskoye,
Akhmirov, and Maralushenskoye, highlighting the
impact of reserve accessibility on technological progress
(Bishimbayeva et al., 2020). The dumps from processing
plants contain more than 10,000 tons of lithium, with
low lithium concentrations ranging from 0.1% to 1.5%
(Hasanov et al., 2023). The ability to access reserves has a
major impact on technological advancement (Berdikulova
et al., 2022).
Primary spodumene beneficiation typically involves
steps like sizing, classification, dense media separation
(DMS), magnetic separation, de-sliming, flotation, and
washing to produce concentrates containing 5–7% lithia
(Legault-Seguin et al., 2016, Oliazadeh et al., 2018,
Yelatontsev et al., 2021). Gravity separation methods,
such as jigging, spiral beneficiation, and shaking tables, are
less effective in separating spodumene from gangue min-
erals due to the small density difference (Manser, 1975).
Heavy liquid beneficiation or dense medium separation has
proven to be successful and serves as the primary concentra-
tion process in spodumene beneficiation. Spodumene has
a reported specific gravity (S.G.) of 3.15, while quartz and
feldspar have S.G. between 2.5 and 2.6, and mica has an
SG between 2.8 and 3.0. The spodumene, therefore, sinks
while lighter silicate minerals float in the dense medium of
appropriate S.G., and thus separate from each other. The
sink product is expected to have a lithium assay approxi-
mately of 7.0% (Li2O). However, the efficiency of DMS
is contingent on the degree of mineral liberation and asso-
ciation at the coarsest grain size. Although DMS is effec-
tive for concentrating spodumene, flotation may still be
required to process the DMS middlings and/or the under-
size fraction which is outside the particle size range hav-
ing a very nominal difference in specific gravity between
the valuables and the rejects (Aghamirian et al., 2012,
Oliazadeh et al., 2018). Especially, it has permitted the
processing of complex or low-grade ores which have other-
wise been regarded as uneconomic or secondary resources
(Tadesse et al., 2019, Xie et al., 2021). However, recov-
ering low-grade spodumene with flotation remains chal-
lenging, even with advanced collectors (Bian et al., 2023).
Therefore, improving the flotation efficiency of low-grade
spodumene is both economically and scientifically impor-
tant. This study investigates the effectiveness of DMS and
froth flotation in beneficiating lithium ore from low-grade
spodumene in Eastern Kazakhstan. The beneficiation pro-
cess involved applying DMS to two sizes of coarser frac-
tions and froth flotation of fines with a mixed collector of
dodecylamine acetate (DAA) and sodium oleate (NaOL),
demonstrating the role of mixed anionic/cationic collector
systems in lithium flotation.
MATERIALS AND METHODS
Materials and Chemicals
The spodumene sample utilized in this study was obtained
from the Akhmetkino deposit in Eastern Kazakhstan. The ore
sample was first crushed to 100% passing 5.00 mm, ground
to a size of 1.00 mm, and classified on –1000/+850 μm,
–850/+500 μm, and –500 μm screens. The two coarse frac-
tions were fed to DMS, and the fines were reground and
screened to –74/+38 μm for the flotation test followed
by desliming at 20 μm. The composition of sample and
separation products was determined by whole-rock analy-
sis using XRF (Rigaku ZSX Primus II) and XRD (Rigaku
Miniflex) for major elements, except for lithium. Lithium
concentration in the feed sample was analyzed by MP-AES
(Agilent). The chemical composition and XRD analysis
of the three composite samples are shown in Table 1 and
Figure 1, respectively. As can be seen from Table 1 the grade
of Li2O in the sample indicates the characteristics of the ore
sample with a high content of gangue and a low content of
lithium. The XRD analysis in Figure 1 illustrates that the
main phases of the ore sample were quartz (SiO2), feldspar
([K,Na]AlSiO3), muscovite (KAl2(AlSi3O10)(OH)2), and
spodumene (LiAl(SiO2)3).
Sodium polytungstate (3Na2WO4∙9WO3∙H2O,
solid density: 2.82 g/cm3) used for DMS was purchased
from TC-Tungsten Compounds, Germany. This nontoxic
solid can be mixed with water to form a liquid with a fluid
density that can be adjusted from pure water with a density
of 1 g/cm3 to a saturated solution with a density of 3.10 g/
cm3 (Skipp et al., 1993). Sodium oleate (NaOL, 97.0%)
and dodecylamine acetate (DAA, 98.0%) were purchased
from the Tokyo Chemical Industry Co, Ltd as a collector in
the batch flotation experiment. Sodium hydroxide (NaOH,
98%), hydrochloric acid, and starch were used as pH regu-
lators and dispersant, respectively. The deionized water (DI
water) with a resistivity of 18.25 MΩ·cm was used for the
experiments. Zeta potential measurements were performed
using an ELSZ-1000 (Otsuka Electronics, Japan).
similarities of associated pegmatite minerals such as quartz,
feldspar, and mica (Gibson et al., 2017). Therefore, devel-
oping comprehensive enrichment schemes that combine
multiple processing methods is essential to efficiently sepa-
rate and extract valuable minerals from complex ores.
In Kazakhstan, there has been significant exploration
and development of lithium-bearing deposits and tailings.
Preliminary estimates indicate promising lithium reserves
in six locations in Eastern Kazakhstan: Yubileynoye,
Akhmetkino, Bakkennoye, Verkhne-Baymurzinskoye,
Akhmirov, and Maralushenskoye, highlighting the
impact of reserve accessibility on technological progress
(Bishimbayeva et al., 2020). The dumps from processing
plants contain more than 10,000 tons of lithium, with
low lithium concentrations ranging from 0.1% to 1.5%
(Hasanov et al., 2023). The ability to access reserves has a
major impact on technological advancement (Berdikulova
et al., 2022).
Primary spodumene beneficiation typically involves
steps like sizing, classification, dense media separation
(DMS), magnetic separation, de-sliming, flotation, and
washing to produce concentrates containing 5–7% lithia
(Legault-Seguin et al., 2016, Oliazadeh et al., 2018,
Yelatontsev et al., 2021). Gravity separation methods,
such as jigging, spiral beneficiation, and shaking tables, are
less effective in separating spodumene from gangue min-
erals due to the small density difference (Manser, 1975).
Heavy liquid beneficiation or dense medium separation has
proven to be successful and serves as the primary concentra-
tion process in spodumene beneficiation. Spodumene has
a reported specific gravity (S.G.) of 3.15, while quartz and
feldspar have S.G. between 2.5 and 2.6, and mica has an
SG between 2.8 and 3.0. The spodumene, therefore, sinks
while lighter silicate minerals float in the dense medium of
appropriate S.G., and thus separate from each other. The
sink product is expected to have a lithium assay approxi-
mately of 7.0% (Li2O). However, the efficiency of DMS
is contingent on the degree of mineral liberation and asso-
ciation at the coarsest grain size. Although DMS is effec-
tive for concentrating spodumene, flotation may still be
required to process the DMS middlings and/or the under-
size fraction which is outside the particle size range hav-
ing a very nominal difference in specific gravity between
the valuables and the rejects (Aghamirian et al., 2012,
Oliazadeh et al., 2018). Especially, it has permitted the
processing of complex or low-grade ores which have other-
wise been regarded as uneconomic or secondary resources
(Tadesse et al., 2019, Xie et al., 2021). However, recov-
ering low-grade spodumene with flotation remains chal-
lenging, even with advanced collectors (Bian et al., 2023).
Therefore, improving the flotation efficiency of low-grade
spodumene is both economically and scientifically impor-
tant. This study investigates the effectiveness of DMS and
froth flotation in beneficiating lithium ore from low-grade
spodumene in Eastern Kazakhstan. The beneficiation pro-
cess involved applying DMS to two sizes of coarser frac-
tions and froth flotation of fines with a mixed collector of
dodecylamine acetate (DAA) and sodium oleate (NaOL),
demonstrating the role of mixed anionic/cationic collector
systems in lithium flotation.
MATERIALS AND METHODS
Materials and Chemicals
The spodumene sample utilized in this study was obtained
from the Akhmetkino deposit in Eastern Kazakhstan. The ore
sample was first crushed to 100% passing 5.00 mm, ground
to a size of 1.00 mm, and classified on –1000/+850 μm,
–850/+500 μm, and –500 μm screens. The two coarse frac-
tions were fed to DMS, and the fines were reground and
screened to –74/+38 μm for the flotation test followed
by desliming at 20 μm. The composition of sample and
separation products was determined by whole-rock analy-
sis using XRF (Rigaku ZSX Primus II) and XRD (Rigaku
Miniflex) for major elements, except for lithium. Lithium
concentration in the feed sample was analyzed by MP-AES
(Agilent). The chemical composition and XRD analysis
of the three composite samples are shown in Table 1 and
Figure 1, respectively. As can be seen from Table 1 the grade
of Li2O in the sample indicates the characteristics of the ore
sample with a high content of gangue and a low content of
lithium. The XRD analysis in Figure 1 illustrates that the
main phases of the ore sample were quartz (SiO2), feldspar
([K,Na]AlSiO3), muscovite (KAl2(AlSi3O10)(OH)2), and
spodumene (LiAl(SiO2)3).
Sodium polytungstate (3Na2WO4∙9WO3∙H2O,
solid density: 2.82 g/cm3) used for DMS was purchased
from TC-Tungsten Compounds, Germany. This nontoxic
solid can be mixed with water to form a liquid with a fluid
density that can be adjusted from pure water with a density
of 1 g/cm3 to a saturated solution with a density of 3.10 g/
cm3 (Skipp et al., 1993). Sodium oleate (NaOL, 97.0%)
and dodecylamine acetate (DAA, 98.0%) were purchased
from the Tokyo Chemical Industry Co, Ltd as a collector in
the batch flotation experiment. Sodium hydroxide (NaOH,
98%), hydrochloric acid, and starch were used as pH regu-
lators and dispersant, respectively. The deionized water (DI
water) with a resistivity of 18.25 MΩ·cm was used for the
experiments. Zeta potential measurements were performed
using an ELSZ-1000 (Otsuka Electronics, Japan).