Siberian Federal University

S. A. Khramenko, Deputy Director of an Industrial Park, e-mail: sergey.khramenko@mail.ru

A. N. Anushenkov, Professor

LLC “RusEngineering”

E. N. Marakushina, Manager of a Laboratory of Carbonic Raw Materials and Other Materials

Ya. A. Tretyakov, Manager of a Mathematical Modeling Department

The estimation of 16 PAHs emission from surface of colloid and dry anode pastes for different temperatures and during transposition of vertical studs on Soderberg anode has been made. Anode paste — colloid (24% of pitch content) or dry (28% of pitch content) — was exposed to heat treatment in laboratory reactor at 140 ^oС, 155 ^oС or 170 ^oС during 60 minutes. The reactor volume was blown through by argon at a speed of 60 l/hour. At the reactor’s output PAHs were caught by liquid nitrogen. An amount and composition of PAHs was determined by the method of highefficiency liquid chromatography. It is shown that between 140 and 170 ^oС emission of PAHs increases in 3 and 5 times from colloid and dry paste, accordingly. Emission of benz(a)pyren (BaPs) increases in 8 and 10 times accordingly. Total emissions of PAHs and BaPs from Soderberg anode are expected considering the temperature distribution on the surface. The temperature distribution on anode surface was measured by mathematical modeling. The contribution of every temperature zone to total emission of PAHs and benz(а)pyren (BaPs) was found. It is shown that the 155–170 ^oС zone (4.7% of anode surface) brings 18.3% of PAHs emission and 19% of BaPs emission. The second source of carcinogenic PAHs in Soderberg technology is open stud hole. Estimation of emissions during transposition of studs was carried out in electrolysis line. Sampling was carried out by remote collector of local evacuation of gases from the open stud hole. Gas flow rate and temperature in the collector was reiterated during sampling. Emission of BaPs in atmosphere increases in two times if time of transposition of anode stud increases from 8 to 12 minutes. The comparison shows that the transposition of studs is more intense source of PAHs and BAPs emission than anode surface.

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