|About this Abstract
||2021 TMS Annual Meeting & Exhibition
||Aluminum Reduction Technology
||On Gaseous Emissions during Alumina Feeding
||Sindre Engzelius Gylver, Åste Hegglid Follo, Vegard Aulie, Espen Sandnes, Helene Marie Eng Granlund, Anders Sørhuus, Kristian Etienne Einarsrud
|On-Site Speaker (Planned)
||Sindre Engzelius Gylver
Aluminium electrolysis involves feeding of alumina into a cryolite based bath. Water originating from alumina as well from air reacts with fluorides and results in HF evolution. Untreated HF gas is a significant environmental and economical issue. HF is however effectively adsorbed in (primary) alumina before being fed back to the cell as secondary alumina, thereby recycling the fluoride. As alumina is fed to the cell, it forms a raft, delaying the dissolution process and linked to several operational challenges.
The goal of the current work is twofold; first, water content is investigated in a lab scale setting, aiming to explain raft porosity, ultimately causing it to float rather than disperse in the bath. Secondly, the evolution of HF is investigated for different aluminas in both a lab scale setting and in industrial measurements performed at Alcoa Mosjøen, aiming to identify correlations between gas evolution and alumina properties.
||Planned: Light Metals