3532 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
precipitate, comprising 99.76% TiO2, 0.20% Al2O3,
0.02% Fe2O3 and 0.03% SiO2. The remaining solution
can be further treated through solvent extraction to extract
rare earths and scandium.
Process Comparison
The hydrometallurgical processes presented in this work
provide different possibilities for comprehensively utiliz-
ing bauxite residue. The hydro-based approach mainly
focuses on recovering different metallic oxides with high
purity, whereas pig iron is the primary product recovered
from the traditional smelting-based process. Figure 6 shows
the flowsheet for hydrometallurgical processes described in
this work and the conventional smelting-based approach.
Table 2 presents a comparative analysis of these processes.
Overall, the hydrometallurgical process is better due to the
potential to recover multiple metallic oxides of high purity
and high volume utilization. The selective recovery of dif-
ferent metallic oxides at various stages of treatment pro-
vides better separation efficiency and a high recovery rate.
While the smelting-based process is relatively simple,
with easier separation and recovery of iron as pig iron, cer-
tain disadvantages restrict the application for large-scale
processing. The critical drawbacks of the smelting process
include high energy consumption due to high temperatures
and difficulties with metal recovery from slag. The slag
generated during smelting needs to be further processed
through a hydrometallurgical process to recover critical
elements (scandium, titanium), resulting in a combined
hydro and pyrometallurgy-based process for comprehensive
recycling.
Conclusions and Recommendations
Bauxite residue is a multi-element industrial waste gener-
ated during the production of alumina. The presence of dif-
ferent elements within bauxite residue makes it a potential
multi-element resource. However, the complex association
of these elements and the complex chemical and physical
characteristics of bauxite residue make the recycling process
challenging. Based on the research work carried out, the
following conclusions are made.
Characterization studies reveal the presence of mul-
tiple elements, with iron, titanium, aluminum, and
scandium being of the highest economic value. The
different elements are associated in the complex
matrix of bauxite residue and are present as com-
pounds or mixed phases, making their separation
difficult.
The hydrometallurgical process includes selective
leaching of different elements in different stages of
Figure 6. Conceptual flowsheets for processing of bauxite residue for metal recovery
Previous Page Next Page