THE SOURCES OF CARCINOGENIC PAH EMISSION IN ALUMINIUM PRODUCTION USING SODERBERG CELLS

摘要

Specific yields were determined for tars, benzo(a)pyrene, diberzo(ah)anthracene and benzo(ghi)perylene from the main PAH sources in aluminium production using Soderberg cells with anode pastes based on medium- (MP) and high- (HP) softening-point pitches. It was evaluated that the most significant source of carcinogens from the Soderberg cell is the open hole during the process stage of repositioning the current-carrying studs. This phase of the work contributes about 60-70% of the total carcinogenic PAH emissions to the atmosphere. It is shown that a replacement of MP with HP results in a decrease of the specific tar yields from all sources, but it does not reduce the specific yield of the carcinogenic PAHs and therefore the carcinogenic danger of this technology.