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Updated: Jul 2, 2026
05:16
UV-Vis Spectroscopic Characterization of Nanomaterials in Aqueous Media
Published on: October 25, 2021
Characterisation of red mud by UV-vis-NIR spectroscopy
Sara J Palmer1, B Jagannadha Reddy, Ray L Frost
1School of Physical and Chemical Sciences, Queensland University of Technology, Brisbane, Queensland 4001, Australia.
Summary
This study used diffuse reflectance spectroscopy to characterize red mud, identifying ferric ions (Fe3+) as responsible for spectral bands. Seawater neutralization did not alter the red mud
Area of Science:
- Materials Science
- Spectroscopy
- Environmental Chemistry
Background:
- Red mud, a byproduct of alumina extraction, contains significant amounts of iron and aluminum.
- Understanding the speciation of iron in red mud is crucial for its potential valorization and environmental management.
Purpose of the Study:
- To characterize red mud using diffuse reflectance spectroscopy (DRS) in the UV-vis-NIR region.
- To identify the ferric ion (Fe3+) responsible for specific spectral bands.
- To investigate the effect of seawater neutralization (SWN) on the structural composition of red mud.
Main Methods:
- Diffuse reflectance spectroscopy (DRS) in the UV-vis-NIR region.
- Electronic spectroscopy for ion identification.
- Vibrational spectroscopy to assess structural changes.
Main Results:
- Diffuse reflectance spectroscopy identified specific NIR and visible spectrum bands attributed to Fe3+ in distorted sixfold coordination.
- For the first time, electronic spectroscopy confirmed the presence and role of ferric ions in red mud spectra.
- Identical spectral patterns before and after seawater neutralization indicated no structural cation substitution.
Conclusions:
- The study successfully characterized red mud using DRS, identifying Fe3+ as the key species responsible for observed spectral features.
- Seawater neutralization was found to have no impact on the structural integrity or cation composition of red mud.
- These findings contribute to a better understanding of red mud's composition, aiding in its potential reuse and environmental assessment.
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