Development of hydrogen-based reduction processes for recovery of iron, alumina, and other valuable materials from bauxite residues
Project scope
- This project will:
- Investigate hydrogen-based reduction of bauxite residues
- Evaluate the role of mineral additives in preventing hercynite formation
- Improve iron reduction efficiency at elevated temperatures
- Facilitate downstream magnetic separation and alumina recovery
- Develop technically and economically viable mineral addition strategies
- Performed on campus - workload to be agreed with Supervisor
- Suitable for School of Engineering research-based courses, such as: ENGN3712, ENGN4200, ENGN4350, ENGN4712, ENGN4718, ENGN8601, and ENGN8602.
- Suitable for both domestic and international students.
Project description
The principal method for producing alumina (the intermediate material for aluminium production) is the Bayer process. This process generates large quantities of bauxite residue — approximately 1–1.5 tonnes per tonne of alumina produced — resulting in global generation of ~150 Mt annually.
With only 2–3% of residues currently utilised, the global inventory has reached ~4.6 Gt and may grow to 10 Gt by 2050. This presents a major environmental and storage challenge, and a significant opportunity for resource recovery, especially since Bauxite residues contain valuable elements such as iron, aluminium, and rare earth elements (e.g., scandium).
Traditional recovery methods often rely on carbothermic reduction, which produces significant CO₂ emissions. Hydrogen-based direct reduction offers a low-emission alternative but faces technical challenges — particularly the formation of hercynite (FeAl₂O₄) at temperatures above 760 °C, which inhibits iron recovery and separation.
Mineral additives such as lime and limestone show promise in preventing hercynite formation and improving downstream separation efficiency. However, further research is required to optimise additive selection and mixing strategies for industrial-scale deployment.
Deliverables
- Experimental evaluation of additive performance (Project 1)
- Design and assessment of additive–residue mixing strategies (Project 2)
- Technical report suitable for thesis submission
- Potential contribution to peer-reviewed publication
- Presentation of findings
Information for applicants
Two students will contribute to this emerging research area:
- Project 1: Evaluation of low-cost mineral additives and their impact on mineral phase transformations during hydrogen reduction of bauxite residues.
- Project 2: Design of mineral additive–bauxite residue mixing strategies suitable for industrial hydrogen-based direct reduction reactors.
Essential skills and background
- Background in chemical engineering, materials engineering, metallurgy, or related field
- Basic understanding of thermodynamics and reaction kinetics Interest in sustainable metallurgy and industrial decarbonisation
- Experience with laboratory experimentation or process modelling (advantageous but not essential)
Desirable requirements
- Prior coursework in extractive metallurgy, mineral processing, or reaction engineering
- Experience with high-temperature processing or hydrogen-based reduction systems
- Familiarity with characterisation techniques such as XRD, SEM, or thermodynamic modelling (e.g., FactSage, HSC, or similar tools)
- Strong data analysis and report writing skills
- Ability to work both independently and collaboratively within a research team
Student takeaways
- Low-emission metallurgical process design
- Hydrogen-based reduction technologies
- Mineral phase transformation analysis
- Sustainable resource recovery
- Experimental and/or modelling-based research
How to apply
If you are interested, please email a brief Expression of interest, along with a copy of your CV (resume) and academic transcript to the project supervisor.