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OP-III-B-15COMBINED TECHNOLOGY OF UTILIZATION OF SO 2 FROMWASTE GASES RELEASED BY ANODE PRODUCTIONOF ALUMINIUM PLANTSPai Z.P. and Simonov A.D.Boreskov Institute of Catalysis SB RAS,Prosp. Akad. Lavrentieva, 5, Novosibirsk 630090, RussiaFax: (383) 326 95 67, E-mail: zpai@catalysis.ruThe development of new technologies for deep cleaning of industrial gases fromtoxic admixtures is an actual problem. Over a long period, the researches on thedevelopment of gas- and liquid-phase processes for cleaning of industrial gases fromdifferent toxic pollutants, such as SO 2 , H 2 S, NO x , As 2 O 3 , HCN etc. have been carriedout in the Boreskov Institute of Catalysis [1, 2]. In particular, it was suggested topurify gas flows resulting from the coke calcination on the production of anode massfor aluminum plants by a combined technology of utilization of sulfur dioxide with theproduction of sodium sulfate as a commercial product. On the production of anodemass, the combustion of mazut (containing up to 4% of sulfur) yields a considerablequantity of sulfur dioxide (about 7 000 mg/nm 3 ).The suggested technology includes the following stages:1. Dry adsorption-catalytic cleaning of gas;2. Liquid-phase cleaning of gas.After a calcination furnace (1), an effluent gas flow is directed to a waste-heatboiler (2), where the gas is cooled to 250-300°С, and then directed to the cyclone(3а) to be cleaned from dust. The degree of gas cleaning from dust is 85-90%. Thenthe gas passes to an adsorber (4) (stage 1) to undergo the dry adsorption-catalyticcleaning. The degree of gas cleaning from sulfur dioxide is 99.0-99.5%. The cleanedgas is discharged into the atmosphere from the cyclone (3b). A reactor-regenerator(5) permits nonstop catalytic regeneration of the adsorbent. The concentrated gasflow is directed from the reactor-regenerator (5) to the cyclone (3c), where it ispurified from adsorbent and catalyst particles. Then the gas flow containing sulfurdioxide is directed to a reactor-absorber (6) (stage 2), where the main reactionsbetween sulfur dioxide and sodium hydroxide solution occur to yield sodium sulfate.The purified gas flow from the reactor-absorber 6 meets a gas flow from the cyclone3b, the combined flow is vented into the atmosphere through a smoke flue. To spraythe absorber, a solution is fed from the tank (7). A portion of the solution from the209