Latest Results from PFC Investigation in China

In the first half year of 2011, PFC investigation has been conducted on five potlines whose line currents are at the range of 200~350kA. The total aluminum output is 1.35 million tons per year. Both PFC caused by anode effects and PFC unrelated to anode effects were monitored and calculated. C3F8 was observed during anode effects for the first time and its peaks were at the same location as C2F6 and CF4 at the timetable. The weigh ratio of C3F8/CF4 was 4.19%, and that of C2F6/CF4 was 11.61%. C3F8 was observed only in the monitoring of two potlines and no C3F8 in the other three potlines. Concentration curves of C3F8 were plotted with C2F6. Percentage of Non Anode Effect PFC (NAE-PFC) of five potlines was calculated. The highest was 92.8% while the potline has the lowest anode effect frequency (AEF) and its AEF is 0.01 AEs/cell-day.