XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 1807
roasting pretreatment was more efficient than direct acid
leaching.
Potential Mechanism Model
According to the analysis results mentioned above, being
suspension oxidation roasted, the vanadium extraction effi-
cient are obviously improved. The potential mechanism
model of enhanced vanadium extraction from shale ore is
shown in Figure 11. CaF2, as an aid leaching agent, is used
in direct acid leaching to generated HF. HF could react
with aluminosilicate mineral in high concentrate acid solu-
tion and contributed to release vanadium from vanadium-
bearing muscovite. However, HF and H+ only gradually
diffused from outer edge into the interior of particles. The
reacting rates are very slow. Meanwhile, concentration of
impurity ion of Al3+, K+, Si4+, and Fe3+ are too high to
affect the final products purity owing to exist of HF and
high concentration of sulfuric acid. Compared with direct
acid leaching, suspension oxidation roasting-acid leaching
provide more efficient method. Decomposition reaction
and dehydroxylation reaction occur in roasting process.
The lattice structure of muscovite was destroyed. Being
roasted, the dense structure became loose and porous. The
changes contribute to the oxidation of V(III) in roasting
and V(V) replaces by H+ in leaching. As the acid and CaF2
dosages drop to below 10 wt.% and 0%, respectively. The
impurity iron concentration can sharply reduce and vana-
dium leaching efficiency increases at least 15% at the same
time. Therefore, suspension oxidation roasting-acid leach-
ing is an environmental-friendly and efficient to promote
vanadium-bearing shale ore resource utilization.
CONCLUSION
In this study, the mechanism of enhanced vanadium extrac-
tion from shale ore by suspension oxidation roasting was
investigated. Compared with the leaching behavior of
Figure 11. The potential mechanism model of enhanced vanadium extraction from shale ore by suspension oxidation roasting
roasting pretreatment was more efficient than direct acid
leaching.
Potential Mechanism Model
According to the analysis results mentioned above, being
suspension oxidation roasted, the vanadium extraction effi-
cient are obviously improved. The potential mechanism
model of enhanced vanadium extraction from shale ore is
shown in Figure 11. CaF2, as an aid leaching agent, is used
in direct acid leaching to generated HF. HF could react
with aluminosilicate mineral in high concentrate acid solu-
tion and contributed to release vanadium from vanadium-
bearing muscovite. However, HF and H+ only gradually
diffused from outer edge into the interior of particles. The
reacting rates are very slow. Meanwhile, concentration of
impurity ion of Al3+, K+, Si4+, and Fe3+ are too high to
affect the final products purity owing to exist of HF and
high concentration of sulfuric acid. Compared with direct
acid leaching, suspension oxidation roasting-acid leaching
provide more efficient method. Decomposition reaction
and dehydroxylation reaction occur in roasting process.
The lattice structure of muscovite was destroyed. Being
roasted, the dense structure became loose and porous. The
changes contribute to the oxidation of V(III) in roasting
and V(V) replaces by H+ in leaching. As the acid and CaF2
dosages drop to below 10 wt.% and 0%, respectively. The
impurity iron concentration can sharply reduce and vana-
dium leaching efficiency increases at least 15% at the same
time. Therefore, suspension oxidation roasting-acid leach-
ing is an environmental-friendly and efficient to promote
vanadium-bearing shale ore resource utilization.
CONCLUSION
In this study, the mechanism of enhanced vanadium extrac-
tion from shale ore by suspension oxidation roasting was
investigated. Compared with the leaching behavior of
Figure 11. The potential mechanism model of enhanced vanadium extraction from shale ore by suspension oxidation roasting