1800 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
oxidation roasting. The change of feed ore and roasted
products in the leaching process will be compared. In this
paper, the effect of leaching parameters on leaching rate,
phase transformation, and micromorphology evolution are
discussed. The findings in this paper can assist in promot-
ing the industrialization of technology and improve the
utilization efficiency of vanadium-bearing shale resources.
EXPERIMENTAL
Materials
Vanadium-bearing shale used in this research was obtained
from Shaanxi province, China. The raw ore was crushed
to –1 mm and then preconcentrated by gravity concentra-
tion and discarding tailing. The preconcentrated ore was
called feed ore in this paper and as raw material for sus-
pension oxidation roasting and direct acid leaching. The
roasted product was obtained from a suspension oxidation
roasting system (Liaoning Dongda Mining Metallurgy Co.,
Ltd) under the following conditions: roasting temperature
of 870 °C–900 °C, feed rate of 20 kg/h, total gas flow of 32
Nm3/h, and air gas(Zhu et al., 2023).
The chemical elemental analysis results of samples are
listed in Table 1. Compared with feed ore, the V2O5 con-
tents of the roasting products were lower. It was owing to
that a small amount of fine material was collected in the
dust bin and returned to the reactor (SOR system diagram
was shown in Figure 4). The content of S of the roasted
product was similar to feed ore, and the content of C
decreased after roasting.
The mineral composition of the feed ore was deter-
mined by X-ray diffraction, and the results were shown in
Figure 1. The feed ore was formed of quartz, muscovite,
kaolinite, limonite, calcite, feldspar, and barite. After roast-
ing, the diffraction peaks of muscovite, kaolinite, limonite,
and calcite disappeared. It indicated that these miner-
als’ lattice structures were destroyed. The diffraction peak
of barite was unchanged after roasting. Comprehensive
analysis of the results of chemical composition and X-ray
diffraction analysis, in the feed ore, S mainly occurred in
barite, so the content of S did not change after roasting. C
mainly occurred in calcite and transformed to CO2 during
the roasting process, therefore, the content of C obviously
decreased after roasting.
The results of vanadium phase and valence distribution
analysis were shown in Figure 2 and Figure 3, respectively.
Aluminosilicate minerals (muscovite and kaolinite) were
the main vanadium-bearing minerals with a vanadium con-
tent of 63.21%. In addition, 35% of vanadium occurred
in free iron oxide (limonite) and very little in carbon. In
the shale ore, 77.72% of vanadium was water and sulfur
acid-insoluble V(III) and the rest was acid-soluble V(IV).
There was no V(V). In the sulfuric acid leaching system,
only V(IV) and V(V) could be dissolved in the leaching
solution. Therefore, it was necessary to realize efficient use
of the resource that destroys vanadium-bearing minerals,
release of central vanadium atoms, and oxidation of low-
valence vanadium.
Table 1. Chemical composition of feed ore and roasted product
Element
Content, %
Element
Content, %
Feed Ore Roasted Product Feed Ore Roasted Product
V2O5 1.67 1.60 Al2O3 6.62 6.32
SiO
2 62.74 64.28 K 1.53 1.46
Na 0.15 0.11 TFe 3.37 3.92
CaO 3.42 4.47 MgO 2.34 1.91
S 0.60 0.66 C 0.86 0.09
P 0.35 0.34 LOI 6.24 0.05
Figure 1. XRD pattern of feed ore and roasted product
oxidation roasting. The change of feed ore and roasted
products in the leaching process will be compared. In this
paper, the effect of leaching parameters on leaching rate,
phase transformation, and micromorphology evolution are
discussed. The findings in this paper can assist in promot-
ing the industrialization of technology and improve the
utilization efficiency of vanadium-bearing shale resources.
EXPERIMENTAL
Materials
Vanadium-bearing shale used in this research was obtained
from Shaanxi province, China. The raw ore was crushed
to –1 mm and then preconcentrated by gravity concentra-
tion and discarding tailing. The preconcentrated ore was
called feed ore in this paper and as raw material for sus-
pension oxidation roasting and direct acid leaching. The
roasted product was obtained from a suspension oxidation
roasting system (Liaoning Dongda Mining Metallurgy Co.,
Ltd) under the following conditions: roasting temperature
of 870 °C–900 °C, feed rate of 20 kg/h, total gas flow of 32
Nm3/h, and air gas(Zhu et al., 2023).
The chemical elemental analysis results of samples are
listed in Table 1. Compared with feed ore, the V2O5 con-
tents of the roasting products were lower. It was owing to
that a small amount of fine material was collected in the
dust bin and returned to the reactor (SOR system diagram
was shown in Figure 4). The content of S of the roasted
product was similar to feed ore, and the content of C
decreased after roasting.
The mineral composition of the feed ore was deter-
mined by X-ray diffraction, and the results were shown in
Figure 1. The feed ore was formed of quartz, muscovite,
kaolinite, limonite, calcite, feldspar, and barite. After roast-
ing, the diffraction peaks of muscovite, kaolinite, limonite,
and calcite disappeared. It indicated that these miner-
als’ lattice structures were destroyed. The diffraction peak
of barite was unchanged after roasting. Comprehensive
analysis of the results of chemical composition and X-ray
diffraction analysis, in the feed ore, S mainly occurred in
barite, so the content of S did not change after roasting. C
mainly occurred in calcite and transformed to CO2 during
the roasting process, therefore, the content of C obviously
decreased after roasting.
The results of vanadium phase and valence distribution
analysis were shown in Figure 2 and Figure 3, respectively.
Aluminosilicate minerals (muscovite and kaolinite) were
the main vanadium-bearing minerals with a vanadium con-
tent of 63.21%. In addition, 35% of vanadium occurred
in free iron oxide (limonite) and very little in carbon. In
the shale ore, 77.72% of vanadium was water and sulfur
acid-insoluble V(III) and the rest was acid-soluble V(IV).
There was no V(V). In the sulfuric acid leaching system,
only V(IV) and V(V) could be dissolved in the leaching
solution. Therefore, it was necessary to realize efficient use
of the resource that destroys vanadium-bearing minerals,
release of central vanadium atoms, and oxidation of low-
valence vanadium.
Table 1. Chemical composition of feed ore and roasted product
Element
Content, %
Element
Content, %
Feed Ore Roasted Product Feed Ore Roasted Product
V2O5 1.67 1.60 Al2O3 6.62 6.32
SiO
2 62.74 64.28 K 1.53 1.46
Na 0.15 0.11 TFe 3.37 3.92
CaO 3.42 4.47 MgO 2.34 1.91
S 0.60 0.66 C 0.86 0.09
P 0.35 0.34 LOI 6.24 0.05
Figure 1. XRD pattern of feed ore and roasted product