About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
|
| Symposium
|
Fundamentals of Sustainable Metallurgy and Processing of Materials
|
| Presentation Title |
Sustainable Pre-reduction of Ferromanganese Oxides with Hydrogen: Heating Rate-Dependent Reduction Pathways and Microstructure Evolution |
| Author(s) |
Anurag Bajpai, Barak Ratzker, Shiv Shankar, Dierk Raabe, Yan Ma |
| On-Site Speaker (Planned) |
Anurag Bajpai |
| Abstract Scope |
The reduction of ferromanganese ores into metallic feedstock is highly energy-intensive and emits substantial amounts of CO2, underscoring the need for sustainable alternatives. Hydrogen-based pre-reduction of manganese-rich ores offers a low-emission pathway to support thermic Fe–Mn alloy production. This study investigates the effect of heating rate (2–20 °C/min) on the hydrogen-based reduction of Nchwaning ore and synthetic Mn2O3–9 wt.% Fe2O3 analog. Non-isothermal thermogravimetric analysis revealed a multistep reduction with overlapping kinetic regimes. Isoconversional analysis showed rising activation energy with conversion, indicating a shift from surface-reaction to diffusion-controlled mechanisms. Interrupted XRD showed slow heating enables complete MnO and Fe formation, while fast heating causes Fe–Mn oxide intermixing. Thermodynamic predictions revealed Mn-stabilized Fe spinel and halite phases. Microstructural analysis showed fine Fe dispersion in MnO matrix at slow heating, versus Fe-rich agglomerates at fast heating. Heating rate thus governs reduction pathway, phase evolution, and microstructure, guiding efficient hydrogen-based ferromanganese processing. |
| Proceedings Inclusion? |
Planned: |