About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
|
| Symposium
|
Rare Metal Extraction & Processing
|
| Presentation Title |
Hydrometallurgical recycling of exhausted iron-molybdate catalysts using ammoniacal leaching process |
| Author(s) |
Muhammad Farhan, Rajiv Srivastava, Sadia Ilyas |
| On-Site Speaker (Planned) |
Muhammad Farhan |
| Abstract Scope |
Iron-molybdate (Fe-Mo) mixed oxides exhibit high catalytic performance in the selective oxidation of methanol to formaldehyde. A high molybdenum content is often necessary to prevent the formation of unselective, iron-rich phases during redox reactions. However, the partial loss of active molybdenum species over time leads to catalyst deactivation and reduced lifespan. Despite this, spent catalysts remain a valuable secondary source of molybdenum, making them attractive for urban mining, although the recycling process remains challenging. In this study, we investigated the ammoniacal leaching of spent Fe-Mo catalysts to understand molybdenum extraction behavior from bimetallic systems. The leaching process was examined in the context of chemical equilibria and the buffering effect of the ammoniacal solution. Over 95% of molybdenum was selectively leached, primarily as MoO42– species, guided by redox potential–pH equilibria. In some cases, transient formation of soluble iron-ammine complexes was also observed, which gradually diminished over time. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Hydrometallurgy, Recycling and Secondary Recovery, Extraction and Processing |