How are PFCs generated during the primary aluminum production process?
When the alumina ore content of the electrolytic bath falls below critical levels optimal for the above chemical reaction to take place, rapid voltage increases occur, termed “anode effects”. During an anode effect, carbon from the anode and fluorine from the dissociated molten cryolite bath combine, producing CF4 and C2F6. These gases are emitted from the exhaust ducting system or other pathways from the cell (e.g., the hood of the cell). The magnitude of PFC emissions for a given level of aluminum production depends on the frequency and duration of anode effects.
