1616 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
V2O5 reserves, more than the sum of vanadium reserves in
other countries in the world (Hu et al., 2021). However,
the grade of V2O5 for most vanadium-bearing shale is less
than 1%, which is accepted as a kind of complex and low-
grade vanadium containing resources (Zhang, 2014). It is
well known that vanadium mainly replaces Al(III) in the
form of V(III) isomorphism and occurs in the octahedron
of mica minerals crystal lattice. Therefore, the destruction
of the lattice and efficient dissolution of vanadium is the
key determining the vanadium leaching efficiency attrib-
uting to the stable structure of mica minerals (Bao et al.,
2020).
At the moment, the two kinds of techniques of pyro-
and hydro-metallurgy combined process and whole hydro-
metallurgical process have been exploited by researchers for
vanadium extraction from vanadium-bearing shale. Jian
et al. (Jian et al., 2018) adopted sodium hydroxide alka-
line roasting and water leaching to extract vanadium form
shale and found that the vanadium leaching ratio attained
84.63%. Vanadium-bearing shale was extracted via roast-
ing with compound additives and sulfuric acid leaching
by Cai et al., and it was discovered that the vanadium
leaching ratio was only 81.07% after calcination at 850°C
(Cai et al., 2015). The whole hydrometallurgical process
was proposed so as to solve relevant issues existing dur-
ing pyro- and hydro-metallurgy combined process. He et
al. (Hu et al., 2017) tried to extract vanadium from shale
with sulfuric acid direct leaching technique and found that
the vanadium leaching ratio was only 74.1% after leach-
ing for 6 h. Wang et al. (Wang et al., 2015) explored the
effect of CaF2 on the whole hydrometallurgical leaching of
vanadium-bearing shale. It was discovered that the leach-
ing ratio of vanadium obviously increased from 47.46% to
92.93% with the addition of 5 wt.% CaF2 after leaching
for 4 h. In order to strengthen the whole hydrometallurgi-
cal leaching process, some researchers tried to add oxidants
to promote the destruction of vanadium-containing mica
structure and improve the vanadium leaching ratio. Huang
et al. (Huang et al., 2015) extracted vanadium from shale
by pressure leaching in O2, and it was found that the vana-
dium leaching ratio was 80.51% under the O2 pressure of
1.0 MPa, leaching temperature of 150°C and leaching time
of 2 h. Ji et al. (Ji et al., 2014) added NaClO3 and CaF2
into the direct sulfuric acid leaching system for vanadium
extraction. The results showed that with the addition of
1.25 wt.% NaClO3 and 12 wt.% CaF2, the leaching ratio
of vanadium achieved more than 90% after leaching for 11
h. Huang et al. (Huang et al., 2020) explored the leaching
behaviours of vanadium with the assistance of MnO2 and
discovered that the leaching ratio of vanadium achieved as
89.3% with the addition of 3 wt.% MnO2 after leaching
for 7.9 h. It can be concluded from the current research sta-
tus for vanadium leaching within vanadium-bearing shale
that the whole hydrometallurgical leaching technique is
more low-carbon and clean compared to pyro- and hydro-
metallurgy combined technology, by which vanadium can
be released and dissolved from vanadium containing miner-
als without high temperature roasting. However, the whole
hydrometallurgical leaching technique commonly suffers
from relatively low leaching ratio, long leaching duration
and high reagents consumption, which hinders the sustain-
able development of green extraction metallurgy technol-
ogy for vanadium-bearing shale.
Ultrasound has been widely applied as an auxiliary
technique to strengthen the hydrometallurgical leaching
process of valuable metals from low-grade mineral ores and
secondary resources(Bao et al., 2023). It is well accepted
that the introduction of ultrasound will obviously increase
the leaching percentage of metals, shorten leaching dura-
tion as well as lower reagent and energies consumption.
Oza et al. (Oza et al., 2011) extracted Ni from spent cata-
lysts via ultrasound-assisted HNO3 leaching. It was found
that the optimal Ni leaching ratio (93%) was obtained
after a long leaching time of 9 h with conventional leach-
ing, while the leaching ratio of nickel achieved as 95%
with ultrasound leaching for only 50 min. Knaislova et al.
(Knaislova et al., 2018) compared the effect of ultrasound
and microwave on the extraction of Cu from deep-sea
manganese using (NH4)2S2O3 as reductant. It was dis-
covered that the leaching ratio of Cu can reach 83% with
ultrasound leaching for 90 min, but the leaching ratio was
only 67% after microwave-assisted leaching for 210 min.
Souada et al. (Souada et al., 2018) investigated the leaching
process of In from end-of-life liquid crystal display (LCD)
and found that the leaching ratio of In was just 13% after
leaching for 4 min without ultrasound, whereas ultrasound
obviously increased the leaching ratio to higher than 82%
at the same conditions. Yu et al. (Yu et al., 2020) reported
that the leaching ratio of Au achieved as 99% at leaching
temperature of 10 °C in the presence of ultrasound, which
is equal to that obtained at traditional leaching at 25°C. In
particular, the unit addition of NaCN can be reduced by
16%.
In order to solve the abovementioned issues concern-
ing to the whole hydrometallurgical leaching technique for
vanadium from vanadium-bearing shale, the ultrasound
was introduced into the oxidative leaching process. In
this study, the leaching kinetics of vanadium in the pres-
ence and absence of ultrasound were comparatively inves-
tigated. Meanwhile, the transformation of the phases,
V2O5 reserves, more than the sum of vanadium reserves in
other countries in the world (Hu et al., 2021). However,
the grade of V2O5 for most vanadium-bearing shale is less
than 1%, which is accepted as a kind of complex and low-
grade vanadium containing resources (Zhang, 2014). It is
well known that vanadium mainly replaces Al(III) in the
form of V(III) isomorphism and occurs in the octahedron
of mica minerals crystal lattice. Therefore, the destruction
of the lattice and efficient dissolution of vanadium is the
key determining the vanadium leaching efficiency attrib-
uting to the stable structure of mica minerals (Bao et al.,
2020).
At the moment, the two kinds of techniques of pyro-
and hydro-metallurgy combined process and whole hydro-
metallurgical process have been exploited by researchers for
vanadium extraction from vanadium-bearing shale. Jian
et al. (Jian et al., 2018) adopted sodium hydroxide alka-
line roasting and water leaching to extract vanadium form
shale and found that the vanadium leaching ratio attained
84.63%. Vanadium-bearing shale was extracted via roast-
ing with compound additives and sulfuric acid leaching
by Cai et al., and it was discovered that the vanadium
leaching ratio was only 81.07% after calcination at 850°C
(Cai et al., 2015). The whole hydrometallurgical process
was proposed so as to solve relevant issues existing dur-
ing pyro- and hydro-metallurgy combined process. He et
al. (Hu et al., 2017) tried to extract vanadium from shale
with sulfuric acid direct leaching technique and found that
the vanadium leaching ratio was only 74.1% after leach-
ing for 6 h. Wang et al. (Wang et al., 2015) explored the
effect of CaF2 on the whole hydrometallurgical leaching of
vanadium-bearing shale. It was discovered that the leach-
ing ratio of vanadium obviously increased from 47.46% to
92.93% with the addition of 5 wt.% CaF2 after leaching
for 4 h. In order to strengthen the whole hydrometallurgi-
cal leaching process, some researchers tried to add oxidants
to promote the destruction of vanadium-containing mica
structure and improve the vanadium leaching ratio. Huang
et al. (Huang et al., 2015) extracted vanadium from shale
by pressure leaching in O2, and it was found that the vana-
dium leaching ratio was 80.51% under the O2 pressure of
1.0 MPa, leaching temperature of 150°C and leaching time
of 2 h. Ji et al. (Ji et al., 2014) added NaClO3 and CaF2
into the direct sulfuric acid leaching system for vanadium
extraction. The results showed that with the addition of
1.25 wt.% NaClO3 and 12 wt.% CaF2, the leaching ratio
of vanadium achieved more than 90% after leaching for 11
h. Huang et al. (Huang et al., 2020) explored the leaching
behaviours of vanadium with the assistance of MnO2 and
discovered that the leaching ratio of vanadium achieved as
89.3% with the addition of 3 wt.% MnO2 after leaching
for 7.9 h. It can be concluded from the current research sta-
tus for vanadium leaching within vanadium-bearing shale
that the whole hydrometallurgical leaching technique is
more low-carbon and clean compared to pyro- and hydro-
metallurgy combined technology, by which vanadium can
be released and dissolved from vanadium containing miner-
als without high temperature roasting. However, the whole
hydrometallurgical leaching technique commonly suffers
from relatively low leaching ratio, long leaching duration
and high reagents consumption, which hinders the sustain-
able development of green extraction metallurgy technol-
ogy for vanadium-bearing shale.
Ultrasound has been widely applied as an auxiliary
technique to strengthen the hydrometallurgical leaching
process of valuable metals from low-grade mineral ores and
secondary resources(Bao et al., 2023). It is well accepted
that the introduction of ultrasound will obviously increase
the leaching percentage of metals, shorten leaching dura-
tion as well as lower reagent and energies consumption.
Oza et al. (Oza et al., 2011) extracted Ni from spent cata-
lysts via ultrasound-assisted HNO3 leaching. It was found
that the optimal Ni leaching ratio (93%) was obtained
after a long leaching time of 9 h with conventional leach-
ing, while the leaching ratio of nickel achieved as 95%
with ultrasound leaching for only 50 min. Knaislova et al.
(Knaislova et al., 2018) compared the effect of ultrasound
and microwave on the extraction of Cu from deep-sea
manganese using (NH4)2S2O3 as reductant. It was dis-
covered that the leaching ratio of Cu can reach 83% with
ultrasound leaching for 90 min, but the leaching ratio was
only 67% after microwave-assisted leaching for 210 min.
Souada et al. (Souada et al., 2018) investigated the leaching
process of In from end-of-life liquid crystal display (LCD)
and found that the leaching ratio of In was just 13% after
leaching for 4 min without ultrasound, whereas ultrasound
obviously increased the leaching ratio to higher than 82%
at the same conditions. Yu et al. (Yu et al., 2020) reported
that the leaching ratio of Au achieved as 99% at leaching
temperature of 10 °C in the presence of ultrasound, which
is equal to that obtained at traditional leaching at 25°C. In
particular, the unit addition of NaCN can be reduced by
16%.
In order to solve the abovementioned issues concern-
ing to the whole hydrometallurgical leaching technique for
vanadium from vanadium-bearing shale, the ultrasound
was introduced into the oxidative leaching process. In
this study, the leaching kinetics of vanadium in the pres-
ence and absence of ultrasound were comparatively inves-
tigated. Meanwhile, the transformation of the phases,